[Federal Register Volume 81, Number 224 (Monday, November 21, 2016)]
[Proposed Rules]
[Pages 83556-83615]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-26962]



[[Page 83555]]

Vol. 81

Monday,

No. 224

November 21, 2016

Part V





 Consumer Product Safety Commission





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16 CFR Part 1241





Safety Standard for Portable Generators; Proposed Rule

  Federal Register / Vol. 81 , No. 224 / Monday, November 21, 2016 / 
Proposed Rules  

[[Page 83556]]


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CONSUMER PRODUCT SAFETY COMMISSION

16 CFR Part 1241

[Docket No. CPSC-2006-0057]
RIN 3041-AC36


Safety Standard for Portable Generators

AGENCY: Consumer Product Safety Commission.

ACTION: Notice of proposed rulemaking.

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SUMMARY: The U.S. Consumer Product Safety Commission has determined 
preliminarily that there may be an unreasonable risk of injury and 
death associated with portable generators. To address this risk, the 
Commission proposes a rule that limits CO emissions from operating 
portable generators. Specifically, the proposed rule would require that 
portable generators powered by handheld spark-ignition (SI) engines and 
Class I SI engines not exceed a weighted CO emission rate of 75 grams 
per hour (g/hr); generators powered by one-cylinder, Class II SI 
engines must not exceed a weighted CO emission rate of 150 g/h; and 
generators powered by Class II SI engines with two cylinders must not 
exceed a weighted emission rate of 300 g/h.

DATES: Submit comments by February 6, 2017.

ADDRESSES: You may submit comments, identified by Docket No. CPSC-2006-
0057, by any of the following methods:
    Electronic Submissions: Submit electronic comments to the Federal 
eRulemaking Portal at: http://www.regulations.gov. Follow the 
instructions for submitting comments. The Commission does not accept 
comments submitted by electronic mail (email), except through 
www.regulations.gov. The Commission encourages you to submit electronic 
comments by using the Federal eRulemaking Portal, as described above.
    Written Submissions: Submit written submissions by mail/hand 
delivery/courier to: Office of the Secretary, Consumer Product Safety 
Commission, Room 820, 4330 East West Highway, Bethesda, MD 20814; 
telephone (301) 504-7923.
    Instructions: All submissions received must include the agency name 
and docket number for this notice. All comments received may be posted 
without change, including any personal identifiers, contact 
information, or other personal information provided, to: http://www.regulations.gov. Do not submit confidential business information, 
trade secret information, or other sensitive or protected information 
that you do not want to be available to the public. If furnished at 
all, such information should be submitted in writing.
    Docket: For access to the docket to read background documents or 
comments received, go to: http://www.regulations.gov, and insert the 
docket number CPSC-2006-0057, into the ``Search'' box, and follow the 
prompts.

FOR FURTHER INFORMATION CONTACT: Janet Buyer, Project Manager, 
Directorate for Engineering Sciences, Consumer Product Safety 
Commission, 5 Research Place, Rockville, MD 20850; telephone: 301-987-
2293; email: [email protected].

SUPPLEMENTARY INFORMATION:

I. Background

    A portable generator is an engine-driven machine that converts 
chemical energy from the fuel powering the engine into rotational 
energy, which, in turn, is converted to electrical power. Reports of 
portable generator-related fatalities and injuries prompted the U.S. 
Consumer Product Safety Commission (Commission or CPSC) to publish an 
advance notice of proposed rulemaking (ANPR) in December 2006 to 
consider whether there may be an unreasonable risk of injury and death 
associated with portable generators (71 FR 74472 (December 12, 2006)). 
The ANPR began a rulemaking proceeding under the Consumer Product 
Safety Act (CPSA). The Commission received 10 comments in response to 
the ANPR. Subsequently, in a two-part technology demonstration program, 
CPSC contracted with the University of Alabama (UA) to conduct a low CO 
emission prototype generator technology development and durability 
demonstration and contracted with NIST to conduct comparative testing 
of an unmodified carbureted generator and prototype generators in an 
attached garage of a test house facility. CPSC staff published a report 
regarding the results of the UA technology demonstration and received 
12 comments in response to this report. NIST published a report 
concerning its comparative testing of generators and received four 
comments in response to its report. The Commission is now issuing a 
notice of proposed rulemaking (NPR) that would establish requirements 
for carbon monoxide emission rates.\1\ The information discussed in 
this preamble is derived from CPSC staff's briefing package for the 
NPR, which is available on CPSC's Web site at: https://www.cpsc.gov/s3fs-public/ProposedRuleSafetyStandardforPortableGenerators.pdf.
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    \1\ The Commission voted (4-1) to publish this notice in the 
Federal Register. Chairman Elliot F. Kaye and Commissioners Robert 
S. Adler, Joseph P. Mohorovic, and Marietta S. Robinson voted to 
approve publication of the proposed rule. Commissioner Ann Marie 
Buerkle voted against publication of the proposed rule.
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II. Statutory Authority

    Portable generators are ``consumer products'' that can be regulated 
by the Commission under the authority of the CPSA. See 15 U.S.C. 
2052(a). Section 7 of the CPSA authorizes the Commission to promulgate 
a mandatory consumer product safety standard that sets forth certain 
performance requirements for a consumer product or that sets forth 
certain requirements that a product be marked or accompanied by clear 
and adequate warnings or instructions. A performance, warning, or 
instruction standard must be reasonably necessary to prevent or reduce 
an unreasonable risk or injury. Id.
    Section 9 of the CPSA specifies the procedure that the Commission 
must follow to issue a consumer product safety standard under section 
7. In accordance with section 9, the Commission may commence rulemaking 
by issuing an ANPR; as noted previously, the Commission issued an ANPR 
on portable generators in December 2006. (71 FR 74472 (December 12, 
2006)). Section 9 authorizes the Commission to issue an NPR including 
the proposed rule and a preliminary regulatory analysis, in accordance 
with section 9(c) of the CPSA and request comments regarding the risk 
of injury identified by the Commission, the regulatory alternatives 
being considered, and other possible alternatives for addressing the 
risk. Id. 2058(c). Next, the Commission will consider the comments 
received in response to the proposed rule and decide whether to issue a 
final rule, along with a final regulatory analysis. Id. 2058(c)-(f). 
The Commission also will provide an opportunity for interested persons 
to make oral presentations of the data, views, or arguments, in 
accordance with section 9(d)(2) of the CPSA. Id. 2058(d)(2).
    According to section 9(f)(1) of the CPSA, before promulgating a 
consumer product safety rule, the Commission must consider, and make 
appropriate findings to be included in the rule, on the following 
issues:
     The degree and nature of the risk of injury that the rule 
is designed to eliminate or reduce;
     the approximate number of consumer products subject to the 
rule;
     the need of the public for the products subject to the 
rule and the

[[Page 83557]]

probable effect the rule will have on utility, cost, or availability of 
such products; and
     the means to achieve the objective of the rule while 
minimizing adverse effects on competition, manufacturing, and 
commercial practices.

Id. 2058(f)(1). Under section 9(f)(3) of the CPSA, to issue a final 
rule, the Commission must find that the rule is ``reasonably necessary 
to eliminate or reduce an unreasonable risk of injury associated with 
such product'' and that issuing the rule is in the public interest. Id. 
2058(f)(3)(A)&(B). Additionally, if a voluntary standard addressing the 
risk of injury has been adopted and implemented, the Commission must 
find that:
     the voluntary standard is not likely to eliminate or 
adequately reduce the risk of injury, or that
     substantial compliance with the voluntary standard is 
unlikely. Id. 2058(f)(3)(D). The Commission also must find that 
expected benefits of the rule bear a reasonable relationship to its 
costs and that the rule imposes the least burdensome requirements that 
would adequately reduce the risk of injury.

Id. 2058(f)(3)(E)&(F).

III. The Product

    A portable generator is an engine-driven machine that converts 
chemical energy from the fuel powering the engine to mechanical energy, 
which, in turn, is converted to electrical power. The engine can be 
fueled by gasoline, liquid propane, or diesel fuel.\2\ A portable 
generator has a receptacle panel for connecting appliances or other 
electrical loads \3\ via a cord with a plug connection. Portable 
generators are designed to be carried, pulled, or pushed by a person.
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    \2\ Engines that operate on gasoline or liquid propane are 
called spark ignition (SI) engines and engines that operate on 
diesel fuel are called compression ignition (CI) engines.
    \3\ An electrical load is an electrical component or portion of 
a circuit that consumes electric power. This is opposed to a power 
source, which produces power, such as a battery or generator. 
Examples of loads include: Appliances, lights, and power tools.
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    Portable generators that are the subject of the proposed standard 
commonly are purchased by household consumers to provide electrical 
power during emergencies (e.g., power outages caused by storms), during 
other times when electrical power to the home has been shut off, when 
power is needed at locations around the home without access to 
electricity, and for recreational activities (e.g., camping or 
recreational vehicle trips). Built-in wheels or optional wheel kits are 
often available for heavier, more powerful units (e.g., units with 3 kW 
power ratings and more).
    One of the primary features of a generator is the amount of 
electrical power the generator can provide on a continuous basis. This 
power, commonly referred to in the industry as ``rated power,'' is 
advertised in units of watts or kilowatts (kW), and can range anywhere 
from under 1 kW for the smallest portable generators, to nominally 15 
kW for the largest portable generators.\4\ Knowing the generator's 
rated power is useful in choosing the appropriate size generator for a 
particular electrical load, such as providing power to power tools, 
household appliances, or recreational equipment.
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    \4\ As we will discuss further herein, the generator's rated 
power is generally a function of the size of the engine. However, 
there is no industry standard for relating the generator's rated 
power to the size of the engine; nor is there any uniform way in 
which electrical output capacity is advertised as ``rated.''
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IV. Risk of Injury

A. Description of Hazard

    Carbon monoxide is a colorless, odorless, poisonous gas formed 
during incomplete combustion of fossil fuels, such as the fuels used in 
engines that power portable generators. The initial effects of CO 
poisoning result primarily from oxygen deprivation (hypoxia) due to 
compromised uptake, transport, and delivery of oxygen to cells. Carbon 
monoxide has a 250-fold higher affinity for hemoglobin than does 
oxygen. Thus, inhaled CO rapidly enters the bloodstream and effectively 
displaces oxygen from red blood cells, resulting in the formation of 
carboxyhemoglobin (COHb).\5\ The heart, brain, and exercising muscle 
are the tissues with the highest oxygen requirements; consequently, 
they are most sensitive to CO-induced hypoxia. The CO-induced hypoxia 
is reflected in the non-specific, flu-like symptoms of mild CO 
poisoning and early symptoms of severe poisoning, e.g., headache, 
lightheadedness, nausea, and fatigue. More severe CO poisoning can 
result in progressively worsening symptoms of vomiting, confusion, loss 
of consciousness, coma, and ultimately, death. The high CO emission 
rate of current portable generators can result in situations where the 
COHb levels of exposed individuals rise suddenly and steeply, causing 
people to experience rapid onset of confusion, loss of muscular 
coordination, and loss of consciousness. This can occur without people 
first experiencing milder CO poisoning symptoms associated with a low, 
or slowly rising, CO level.
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    \5\ COHb, expressed as a percentage, reflects the percentage 
share of the body's total hemoglobin pool occupied by CO. Although 
the relationship is not absolute, percent COHb levels can provide a 
useful index of CO poisoning severity. It is measured with a blood 
sample from the exposed person.
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B. Incident Data

1. Portable Generator Carbon Monoxide Fatalities
    The Commission publishes an annual report that summarizes CO 
incidents associated with engine-driven generators and other engine-
driven tools.\6\ The Commission is using this report to provide the 
base number of incidents for the rulemaking. CPSC staff set a date of 
May 21, 2015, as a cut-off for the incident data used in the briefing 
package. As of May 21, 2015, CPSC databases contained reports of at 
least 751 generator-related consumer CO poisoning deaths resulting from 
562 incidents that occurred from 2004 through 2014.\7\ Due to incident 
reporting delays, statistics for the two most recent years, 2013 and 
2014, are incomplete because data collection is ongoing. Therefore, the 
numbers for these years will likely increase.\8\ Figure 1 shows the 
count of deaths involving a generator derived from CPSC databases for 
each of these years. Note that reporting of generator-related deaths is 
not a statistical sample or a complete count of incidents.
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    \6\ These numbers are taken from a June 2015 reported by the 
CPSC, Hnatov, Matthew, Incidents, Deaths, and In-Depth 
Investigations Associated with Non-Fire Carbon Monoxide from Engine-
Driven Generators and Other Engine-Driven Tools, 2004-2014, U.S. 
Consumer Product Safety Commission, Bethesda, MD, June 2015. (Docket 
Identification CPSC-2006-0057-0026, available online at: 
www.regulations.gov).
    \7\ Id.
    \8\ Note that the epidemiological benefits analysis and 
preliminary regulatory analysis, discussed in Sections IV and X, do 
not include the 85 deaths reported to CPSC as of May 21, 2015, for 
the years 2013 and 2014 because reporting for these years is 
considered incomplete. The epidemiological benefits analysis and 
preliminary regulatory analysis also exclude incidents involving 
generators that are out of the scope of the proposed rule (7 deaths 
in 5 incidents). Therefore, the Commission's epidemiological and 
regulatory analyses are based on 659 deaths in 493 incidents that 
occurred from 2004 through 2012.

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[GRAPHIC] [TIFF OMITTED] TP21NO16.003

2. Portable Generator Carbon Monoxide Injuries
    Based on CPSC's National Electronic Injury Surveillance System 
(NEISS) database,\9\ CPSC estimates that for the 9-year period of 2004 
through 2012, there were 8,703 CO injuries associated with generators 
seen in emergency departments (ED). This estimate should not be 
considered definitive because physicians have noted difficulty in 
correctly diagnosing these injuries. Carbon monoxide poisoning may 
mimic many nonfatal conditions, including alcohol or drug intoxication, 
psychiatric disorders, flulike illnesses, and other conditions that can 
lead to misdiagnosis. Measurement of COHb levels in the victim's blood, 
which could confirm CO poisoning, can also be confounded based on the 
time elapsed and any supplemental oxygen treatment administered, which 
can lower COHb counts prior to measurement. In addition, in some 
incidents, first responders transported severely poisoned victims found 
at the scene directly to a medical facility with a hyperbaric oxygen 
(HBO) chamber \10\ for treatment rather than to a hospital ED. These 
incidents would not have been captured in NEISS. For these reasons, the 
Commission believes that the injury estimate for this proposed rule may 
be low.
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    \9\ The NEISS database is a national probability sample of 
hospitals in the United States and its territories. Patient 
information is collected from each NEISS hospital for every 
emergency visit involving an injury associated with consumer 
products. From this sample, the total number of product-related 
injuries treated in hospital emergency rooms nationwide can be 
estimated.
    \10\ An HBO chamber is a facility used for exposing patients to 
100 percent oxygen under supra-atmospheric conditions, to shorten 
the time it would otherwise normally take for the CO to leave the 
bloodstream and to increase the amount of oxygen dissolved in the 
blood. A broad set of recommendations has been established for HBO 
treatment for CO poisoning, which includes a COHb level above 25 
percent, loss of consciousness, severe metabolic acidosis, victims 
with symptoms such as persistent chest pain or altered mental 
status, and pregnant women. Treatment is not recommended for mild-
to-moderate CO poisoning victims, other than those at risk for 
adverse outcomes.
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    In addition to using the NEISS database to estimate CO poisoning 
injuries for the years 2004 through 2012, the Commission examined the 
narratives of the 292 records of CO-related ED visits to NEISS-member 
hospitals associated with generators for the years 2004 through 2014. 
The narratives helped illustrate the range of treatments received, the 
symptoms, and the reasons why victims went to a hospital ED.\11\
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    \11\ Hnatov, Matthew, Summary of NEISS Records Associated with 
Carbon Monoxide Exposure Cases Related to Engine-Driven Generators 
in 2004 through 2014, U.S. Consumer Product Safety Commission, 
Bethesda, MD, November 2015. (Docket Identification CPSC-2006-0057-
0028, available online at: www.regulations.gov).
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    The Commission used the Injury Cost Model (ICM) to estimate the 
number of injuries treated in locations other than hospital EDs. The 
ICM uses empirical relationships between the characteristics of 
injuries and victims in cases initially treated in hospital EDs and 
those initially treated in other medical settings (e.g., physicians' 
offices, ambulatory care centers, emergency medical clinics), based 
primarily on data from the Medical Expenditure Panel Survey,\12\ to 
estimate the number of medically attended

[[Page 83559]]

injuries treated outside of hospital EDs. The ICM also analyzes data 
from the Nationwide Inpatient Sample of the Healthcare Cost and 
Utilization Project \13\ to project the number of direct hospital 
admissions bypassing the hospital EDs. According to the ICM estimates, 
there were an additional 16,660 medically attended CO injuries 
involving generators during 2004-2012. Consequently, based on NEISS and 
ICM estimates, there was a minimum of about 25,400 medically attended 
CO injuries treated during the 9-year period. This is a ratio of almost 
39 generator-related CO injuries to every CO death that occurred in 
that period.
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    \12\ The Medical Expenditure Panel Survey (MEPS) is a nationally 
representative survey of the civilian non-institutionalized 
population that quantifies individuals' use of health services and 
corresponding medical expenditures. The MEPS is administered by the 
Agency for Healthcare Research and Quality (U.S. Department of 
Health & Human Services). The MEPS has been collected continuously 
since 1999 and is the principal data set used to monitor medical 
spending in the United States.
    \13\ The National (Nationwide) Inpatient Sample (NIS) is part of 
a family of databases and software tools developed for the 
Healthcare Cost and Utilization Project (HCUP). The NIS is the 
largest publicly available all-payer inpatient health care database 
in the United States, yielding national estimates of hospital 
inpatient stays. HCUP is a family of health care databases and 
related software tools and products developed through a federal-
state-industry partnership and sponsored by the Agency for 
Healthcare Research and Quality (U.S. Department of Health & Human 
Services).
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    Table 1 presents a list of the most commonly identified symptoms 
given in the NEISS case narratives of 292 cases involving generator-
related CO injuries that occurred in the 11-year period from 2004 
through 2014. In many cases, multiple symptoms were reported, but in 29 
percent of the cases (85 of 292), symptoms were not described in the 
NEISS narrative, although the diagnosis was reported. The weighted 
proportion of the total appears to account for the selection 
probabilities of each case.

   Table 1--Most Common Symptoms Reported in NEISS CO Poisoning or CO
             Exposure Cases Involving Generators, 2004-2014
------------------------------------------------------------------------
                                                              Weighted
                 Common symptoms *                   Cases   proportion
                                                                 (%)
------------------------------------------------------------------------
Headache..........................................      73            27
Nausea, Felt Sick.................................      77            30
Dizzy/Confused, Disorientation, Lightheaded.......      70            25
Vomiting..........................................      34            16
Passed Out, Unconscious, Unresponsive.............      18             5
------------------------------------------------------------------------
* Cases may appear multiple times in Table 1 because victims may have
  exhibited multiple symptoms.

    Table 2 presents a summary of the reasons why the patients said 
they went to the emergency room for treatment or to be checked out. In 
the majority of cases, the medical records, from which the narratives 
were abstracted, provided little or no information on how the patients 
knew they needed to go to the emergency room or how they got there. 
However, in 47 of the 93 cases in which this information was available, 
the patient realized something was wrong and arranged to get to the 
emergency room.

 Table 2--Reason Victim Went to ED for NEISS CO Poisoning or CO Exposure
                  Cases Involving Generators, 2004-2014
------------------------------------------------------------------------
                                                             Weighted
                 Reason                        Cases      proportion (%)
------------------------------------------------------------------------
Victim realized something was wrong and               47              23
 arranged to get to ER..................
Discovered in distress by family,                     24               6
 friend, or due to a welfare check......
Carbon monoxide alarm sounded, arranged               22               9
 to get to ER...........................
Unknown why or how taken to Emergency                199              62
 Room...................................
                                         -------------------------------
    Total...............................             292             100
------------------------------------------------------------------------

    Table 3 presents a summary of the location of the generator 
involved with the CO poisoning event. The three most common locations 
identified were ``Inside the home'' (33%); ``Inside the garage'' (25%); 
and ``In the basement'' (18%). In 11 percent of the reported cases, the 
generator was located outside. In half of the ``Outside the home'' 
scenarios, the narrative specifically states the location was near a 
window, door, or air conditioner.

 Table 3--Location of Generator in Cases Reported in NEISS CO Poisoning
       or CO Exposure Cases Associated With Generators, 2004-2014
------------------------------------------------------------------------
                                                              Weighted
                Generator location                   Cases  proportion *
                                                                 (%)
------------------------------------------------------------------------
Inside the home...................................      86            33
Inside the garage.................................      70            25
In the basement...................................      56            18
Outside the home..................................      29            11
Other/Unknown.....................................      51            14
                                                   ---------------------
  Total...........................................     292           100
------------------------------------------------------------------------
* Percentages do not sum to 100% due to rounding.

    The high number of estimated injuries relative to fatalities 
suggests that many more people leave the scene of the generator, are 
rescued, or seek care than fatally succumb to CO poisoning. As detailed 
in subsequent sections, reduced CO emissions will greatly extend the 
time it takes for CO exposures to result in incapacitation and 
subsequent death. Moreover, in some cases, reduced CO emissions will 
actually prevent incapacitation and death from happening, even if an 
individual does not leave the exposure location. In situations where a 
generator is operated indoors, the extended window of time will allow 
exposed individuals a much greater chance of terminating their CO 
exposure or increase the chance of being found by others before serious 
injury and/or death can occur. Exposure termination could occur for 
several reasons, including the following:
     Exposed individuals might leave the exposure location to 
engage in everyday activities (e.g., work, school),

[[Page 83560]]

without necessarily being aware of any developing CO hazard.
     In some cases, exposure termination might occur without 
the individual leaving the location, simply because the generator runs 
out of fuel, or power is restored and the generator is shut down in 
response, which allows CO levels to decay naturally without reaching 
lethal exposure.
     Exposed individuals might respond to a CO alarm 
activation.
     Exposed individuals might recognize a growing health 
concern and leave to seek treatment or summon help (call a friend, 
relative, or 9-1-1), even if they do not necessarily recognize CO 
emissions as the cause of early nonspecific adverse health effects of 
CO poisoning.
     Exposed individuals might be found in an impaired state by 
other, lesser affected, co-exposed individuals who had been in 
locations farther away from the generator.
     Exposed individuals might be found by concerned outside 
parties conducting welfare checks, or by outside parties simply 
arriving at their home for other reasons, such as, to co-commute to 
work, a social or official visit, or the return home of a co-occupant 
from work or school.
    The Commission notes that all the reasons specified above for 
exposure termination have been reported in incidents where there are 
survivors of carbureted, generator-related CO poisoning. More such 
cases would be expected with reduced CO emissions, due to an overall 
downward shift in expected CO poisoning severity. The Commission 
recognizes that consumers cannot be relied upon to react appropriately 
to any indication of a CO exposure, and that even those who recognize a 
developing CO hazard, might decide to enter the area where a generator 
is located in an attempt to switch it off. This behavior is known to 
have resulted in lethal outcomes with carbureted generators because CO 
can accumulate to levels that can cause near-immediate loss of 
consciousness due to hypoxia/anoxia. However, with reduced CO 
emissions, the peak CO levels attained in an unventilated area where 
the generator is operated will be considerably lower than the level 
that would cause near-immediate loss of consciousness. This potentially 
could reduce the incidence of death among individuals who enter an 
unventilated area to turn off a generator, by allowing them time to 
egress the area before being overcome.

C. Hazard Characteristics

    As stated in the previous section, as of May 2015, there were 562 
incidents involving fatalities from portable generators reported to 
CPSC, which occurred between 2004 through 2014. CPSC assigned In-Depth 
Investigations (IDI) for 535 of these 562 incidents (95 percent), to 
gather more detailed information about the incident and the product(s) 
in use. CPSC categorized the incident data in the IDI reports according 
to the location where the incident occurred:
     75 percent of deaths (565 deaths, 422 incidents) occurred 
in a fixed-structure home location, which includes detached and 
attached houses, apartments, fixed mobile homes, and cabins used as a 
permanent residence;
     16 percent (117 deaths, 81 incidents) occurred at non-
fixed-home locations or temporary structures, such as trailers, horse 
trailers, recreational vehicles (RV), cabins (used as a temporary 
shelter), tents, campers, and boats, and vehicles in which the consumer 
brought the generator on board or into the vehicle;
     6 percent (48 deaths, 46 incidents) occurred in external 
structures at home locations, such as sheds and detached garages;
     3 percent (21 deaths, 13 incidents) occurred at unknown or 
other locations.
    In the same 11-year period, 42 deaths from 30 incidents \14\ 
occurred with the generator operating outdoors, where the exhaust 
infiltrated into a nearby fixed-structure home, a non-fixed-structure 
home, or temporary shelter.\15\ See Figure 2.
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    \14\ These figures exclude two deaths in 2011 caused by a 
stationary generator operated outdoors.
    \15\ Hnatov, Matthew, Carbon Monoxide Deaths Associated with 
Engine-Driven Generators Located Outdoors in 2004 through 2014, U.S. 
Consumer Product Safety Commission, Bethesda, MD, November 2015. 
(Docket Identification CPSC-2006-0057-0028, available online at 
www.regulations.gov).

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[GRAPHIC] [TIFF OMITTED] TP21NO16.004

    Of the 565 deaths (422 incidents) that occurred at a fixed 
structure home:
     45 percent (256 deaths, 191 incidents) occurred when the 
generator was operated in the living space \16\ of the house;
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    \16\ Used here, living space includes all rooms, closets, 
doorways and unidentified areas inside a home, but does not include 
basements, which are treated as a separate category.
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     25 percent (140 deaths, 108 incidents) occurred when the 
generator was in the attached garage or enclosed carport;
     25 percent (139 deaths, 98 incidents) occurred when the 
generator was in the basement or crawlspace;
     3 percent (16 deaths, 12 incidents) occurred when the 
generator was operated outside; \17\
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    \17\ Another 28 deaths from 19 incidents occurred with 
generators operating outside structures other than fixed-structure 
home sites, such as RV, camper or trailer, vehicle, boat, or cabin 
used other than as a permanent residence.
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     2 percent occurred when the generator was at the fixed-
structure home site, but exact location was unknown.

See Figure 3.

[[Page 83562]]

[GRAPHIC] [TIFF OMITTED] TP21NO16.005

    The reason the generator was needed was identified in more than 80 
percent of the 562 incidents. Following are the three biggest causes:
     27 percent (152 incidents) were associated with the use of 
generators during a temporary power outage stemming from a weather 
problem or a problem with power distribution;
     21 percent of the fatal incidents (116 incidents) were 
associated with the use of generators after a power shutoff by the 
utility company for nonpayment of a bill, a bill dispute, or other 
reason.
     19 percent of the fatal incidents (109 incidents) did not 
indicate why the generator was in use, or why there was no electricity 
at the location of the incident.
    Of the 152 fatal incidents associated with a power outage due to 
weather or a problem with power distribution, 93 percent were due to 
specific weather conditions. Ice or snow storms are associated with the 
largest percentage of weather-related CO fatal incidents, accounting 
for nearly half (49%) of the power outage-related incidents. Hurricanes 
and tropical storms were associated with 28 percent of CO fatal 
incidents. More than half (31 of 61) of the generator-related CO 
fatalities that were hurricane- or tropical storm-related (20 of 42 
fatal incidents) occurred in 2005, a year of above-average hurricane 
activity.
    The size of the generator involved in a CO fatality was identified 
in 45 percent of the 562 incidents. Because most of the generators that 
were associated with fatal CO poisoning were gasoline-fueled,\18\ staff 
categorized the size of the generator by using the U.S. Environmental 
Protection Agency's (EPA) classification of the small SI engine 
powering it: A handheld engine \19\; a non-handheld, Class I engine; or 
a non-handheld, Class II engine.\20\ The incidents involving generators 
powered by non-handheld, Class II engines were then divided by whether 
the engine had a single cylinder or twin cylinders.\21\ In the majority 
of cases (55%), CPSC staff was unable to obtain sufficient information 
to be able to categorize the generator into one of these 
classifications. In the incidents where engine classification could be 
determined, slightly more than one-third (35 percent) involved Class I 
engine powered generators, and slightly less than two-thirds (63 
percent) involved single-cylinder, Class II

[[Page 83563]]

engine-powered generators. See Figure 4. There were two incidents 
involving generators powered by handheld engines that caused one death 
in each incident. There were three incidents involving generators 
powered by twin-cylinder, Class II engines that caused seven deaths. 
Two of the incidents were single-death incidents, and the third 
incident, with the generator operating outside an RV, caused five 
deaths inside the RV.
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    \18\ In 52 of the 562 incidents, the fuel type could not be 
ascertained. Of the 510 cases where the fuel type used in the 
generator was known, 99 percent (506 of 510) were gasoline-fueled 
generators. Of the remaining incidents, three involved propane-
fueled generators, and the other incident involved a diesel-fueled 
generator.
    \19\ Although handheld engines generally are used in equipment 
that is held or supported by an operator during use (such as 
trimmers), handheld engines may also be used to power non-handheld 
equipment, such as smaller portable generators.
    \20\ The EPA broadly categorizes small SI engines as either non-
handheld or handheld, and within each of those categories, further 
distinguishes them into different classes, which are based upon 
engine displacement. Non-handheld engines are divided into Class I 
and Class II, with Class I engines having displacement above 80 cc 
up to 225 cc, and Class II engines having displacement at or above 
225 cc, but with maximum power of 19 kilowatts (kW). Handheld 
engines, which are divided into Classes III, IV, and V, are all at 
or below 80 cc.
    \21\ When the IDI did not report the generator's engine 
displacement, or it was not obtainable from other information in the 
IDI, staff considered the power rating of the generator, if the IDI 
contained information regarding the power rating of the generator. 
Staff classified generators with a reported wattage of 3.5 kW and 
larger as powered by a Class II engine and those less than 3.5 kW as 
powered by either a handheld or a Class I engine. To distinguish the 
handheld powered generators from the Class I powered generators when 
there was no information to ascertain the engine displacement, 
generators with wattage of 2 kW to 3.5 kW were considered to have a 
Class I engine. To distinguish the single-cylinder Class II engines 
from the twin-cylinder Class II engines, staff determined from a 
search of EPA's exhaust emission certification database 
(www3.epa.gov/otaq/certdata.htm#smallsi) that twin-cylinder, class 
II engines generally have a maximum engine power of nominally 12 kW 
and higher. Based on manufacturers' generator specifications 
available online, generators with engines with power equal to or 
greater 12 kW, typically have a rated power of 9kW and higher. 
Therefore, staff considered generators with rated power of 3.5 kW up 
to 9 kW to be powered by a single-cylinder, Class II engine, and 
those 9 kW and greater to be powered by a twin-cylinder, Class II 
engine when there was no information to ascertain the engine 
displacement and number of cylinders.
[GRAPHIC] [TIFF OMITTED] TP21NO16.006

V. Overview of Proposed Requirements

    The proposed standard would apply to portable generators powered by 
small handheld and non-handheld SI engines. The Commission categorized 
the size of the generator using the EPA's classification of the small 
SI engine powering it: A handheld engine, a non-handheld Class I 
engine, or a non-handheld Class II engine. The Commission further 
categorized the generators powered by non-handheld Class II engines by 
whether the engine had a single cylinder or twin cylinders. The 
Commission defines the generator categories (as distinguished from the 
engine categories) as follows:
     A handheld generator is a generator powered by an SI 
engine with displacement of 80 cc or less;
     A class 1 generator is a generator powered by an SI engine 
with displacement greater than 80 cc but less than 225 cc;
     A class 2 single cylinder generator is a generator powered 
by an SI engine with one cylinder having displacement of 225 cc or 
greater, up to a maximum engine power of 25 kW; and
     A class 2 twin cylinder generator is a generator powered 
by an SI engine with two cylinders having a total displacement of 225 
cc or greater, up to a maximum engine power of 25 kW.
    Although the Commission categorized generators based on the EPA 
classification of the engines powering them, it is important to 
distinguish these engines from the portable generators that they are 
used in because the engines are also used in other products. To provide 
a clear distinction, the Commission refers to engines according to 
EPA's classification: Handheld engines, non-handheld Class I engines, 
and non-handheld Class II engines, while referring to portable 
generators according to the Commission's definitions, handheld 
generators, class 1 generators, class 2 single-cylinder generators and 
class 2 twin-cylinder generators.
    Generators within the scope of the proposed rule provide receptacle 
outlets for AC output circuits and are intended to be moved, although 
not necessarily with wheels. Products that would not be covered by the 
proposed rule include permanently installed stationary generators, 50 
hertz generators, marine generators, generators permanently installed 
in recreational vehicles, generators intended to be pulled by vehicles, 
generators intended to be mounted in truck beds, and generators that 
are part of welding machines. Generators powered by compression-
ignition (CI) engines (engines fueled by diesel) are also excluded from 
the scope of the proposed rule. These inclusions and exclusions are 
largely consistent with the scope of the two U.S. voluntary standards 
for portable generators, UL 2201--Safety Standard for Portable 
Generator Assemblies and PGMA G300--Safety and Performance of Portable 
Generators.
    The great majority of the units that fall within the scope of the 
proposed standard are gasoline-fueled, but portable generators powered 
by engines fueled by liquid propane (LP) present similar risks of CO 
poisoning, and these units also would be covered by the proposed rule. 
Some portable generators can operate fueled by gasoline, LP and natural 
gas, and these would also be covered by the scope of the proposed rule.
    The proposed rule specifies different limits on weighted carbon 
monoxide emission rates for different classes of generators in 
recognition of the effects

[[Page 83564]]

of factors such as engine size and other engine characteristics on CO 
emissions, generator size, weight, and hazard patterns and the 
different challenges that may be faced in meeting CO emission rates 
expressed in grams per hour. The performance requirements for the 
different classes of generators also have a scaling factor of 1.5 
applied to the technically feasible rates to account for production 
variation. Specifically, the proposed rule would require that handheld 
generators and class 1 generators not exceed a weighted CO rate of 75 
grams per hour (g/hr); class 2 single-cylinder generators not exceed a 
weighted CO emission rate of 150 g/hr; and class 2 twin-cylinder 
generators not exceed a weighted CO emission rate of 300 g/h. The 
weighted emission rates are based on weighting of six modes of 
generator operation, ranging from maximum generator load capability 
(mode 1) to no load (mode 6), similar to a procedure used by EPA to 
certify compliance with its emission standards for small SI engines. 
More detail about this procedure can be found in CPSC's staff briefing 
package. The performance requirements apply when generators operate at 
normal oxygen content; however, the Commission remains interested in CO 
emissions when generators operate at reduced oxygen content of 17 
percent. The Commission welcomes comments on the advantages and 
disadvantages of setting performance requirements at 17 percent oxygen 
instead of normal oxygen as well as comments on the technically 
feasible CO emission rates for generators operating at 17 percent 
oxygen, for each of the generator categories. Furthermore, the 
Commission welcomes comments on the test methods for CO emissions in 
both normal oxygen and 17 percent oxygen in Tab J, Appendices A2 and A3 
of the staff's briefing package.
    The proposed rule does not dictate how generators would meet the CO 
emission limits. Rather, under the proposed rule, firms have the 
flexibility to determine the appropriate technology to meet the 
specified performance requirements. To determine feasibility and to 
estimate likely costs of the proposed rule, staff's briefing package, 
and this preamble, discuss ways that staff believes companies might 
modify generators to meet the CO emission limits. However, companies 
could use other approaches.
    The proposed rule describes the test procedure and equipment that 
the Commission would use to assess compliance with the standard. 
Manufacturers, however, need not use this particular test, so long as 
the test they use effectively assesses compliance with the standard. 
The Commission believes this approach provides added flexibility to 
manufacturers to reduce testing burdens. The Commission welcomes 
comments on the benefits and costs of this approach versus requiring a 
specifc test method for manufacturers to demonstrate compliance.
    In accordance with Section 9 of CPSA, the proposed rule contains a 
provision that prohibits a manufacturer from ``stockpiling,'' or 
substantially increasing the manufacture or importation of noncomplying 
generators between the date that the proposed rule may be promulgated 
as a final rule, and the final rule's effective date. The rule would 
prohibit the manufacture or importation of noncomplying portable 
generators by engine class in any period of 12 consecutive months 
between the date of promulgation of the final rule and the effective 
date, at a rate that is greater than 125% of the rate at which they 
manufactured or imported portable generators with engines of the same 
class during the base period for the manufacturer. The base period is 
any period of 365 consecutive days, chosen by the manufacturer or 
importer, in the 5-year period immediately preceding promulgation of 
the rule.
    Generator sales can vary substantially from year to year, depending 
upon factors such as widespread power outages caused by hurricanes and 
winter storms. Annual unit shipment and import data obtained by CPSC 
staff show that it has not been uncommon for shipments to have varied 
by 40 percent or more from year to year at least once in recent years. 
The anti-stockpiling provision is intended to allow manufacturers and 
importers sufficient flexibility to meet normal changes in demand that 
may occur in the period between promulgation of a rule and its 
effective date, while limiting their ability to stockpile noncomplying 
generators for sale after the effective date. The Commission seeks 
comments on the proposed product manufacture or import limits and the 
base period for the stockpiling provision.

VI. CPSC Technical Analysis and Basis for Proposed Requirements

A. CPSC's Two-Part Prototype Low CO Emission Generator Technology 
Demonstration Program

    CPSC staff developed a two-part technology demonstration program to 
demonstrate that the small SI engine powering a commercially available 
portable generator could be modified with existing emission control 
technology to reduce its CO emission rate to levels expected to reduce 
the risk of fatal and severe CO poisoning. The objective of the first 
part of the program was to develop, from a current carbureted engine-
driven generator, a prototype with a CO emission rate reduced to the 
lowest technically feasible level: (1) Without negatively impacting the 
engine's power output, durability, maintainability, fuel economy, and 
risk of fire and burn; and (2) while also ensuring that the engine 
continued to meet EPA's small SI engine exhaust emission standard for 
hydrocarbons and oxides of nitrogen (HC+NOX), to which the 
unmodified OEM version of the engine was originally labeled as being 
certified. For this, CPSC staff sought a target CO emission rate 
reduction of 90 percent. The objective of the second part of the 
program was to assess the efficacy of the prototype generator in 
reducing occupant exposure profiles created by its operation in a fatal 
scenario commonly reported in CPSC's incident data compared to the 
exposure profiles created by the unmodified carbureted generator.\22\
---------------------------------------------------------------------------

    \22\ Complete documentation on the prototype generator and both 
parts of the demonstration program is provided in Buyer, Janet, 
Technology Demonstration of a Prototype Low Carbon Monoxide Emission 
Portable Generator, September 2012. (available online at: http://www.cpsc.gov/PageFiles/129846/portgen.pdf and in www.regulations.gov 
in docket identification CPSC-2006-0057-0002).
---------------------------------------------------------------------------

Part One: Prototype Development and Durability Testing at University of 
Alabama
    The Commission contracted with the University of Alabama (UA) to 
conduct the prototype development and durability phase of the program. 
The prototype development started with a commercially available 
generator with an advertised continuous electrical power output rating 
of 5.0 kW that was powered by a small, air-cooled, single-cylinder non-
handheld Class II carbureted engine with a 389 cubic centimeter (cc) 
displacement and overhead valve (OHV) configuration. The prototype was 
a modification of that engine. To develop the prototype, UA replaced 
the engine's carburetor with a closed-loop electronic fuel-injection 
(EFI) system, used an oxygen sensor in the exhaust for closed-loop 
fuel-control feedback, tuned the fuel control to stoichiometry \23\ and 
replaced the muffler with a muffler that had a small three-way catalyst 
(TWC) integrated into it. UA subjected the

[[Page 83565]]

prototype generator to a durability program for a total of 500 hours, 
which was the manufacturer's rated useful life of the engine at the 
time of the program. Simultaneous to the durability program on the 
prototype generator, UA subjected a baseline unmodified carbureted 
generator, the identical model to the prototype generator before 
modification, to the same durability program. UA made periodic emission 
measurements on both the prototype and the unmodified carbureted 
generator during the 500 hours of operation to compare the performance 
of the prototype to the baseline unmodified carbureted generator. After 
the 500-hour durability program concluded on both the baseline 
carbureted generator and the prototype generator, an independent 
laboratory, Intertek Carnot Emission Services (CES), conducted end-of-
life emission testing, both with the engine installed in the generator 
as well as on a dynamometer,\24\ in accordance with the EPA small SI 
engine test procedures. The purpose of this testing was to ascertain 
whether, at the end of the engine's rated useful life, the prototype 
engine's emissions would meet: (1) The EPA's Phase 2 requirements for 
HC+NOX, and (2) CPSC staff's target reduction for the 
exhaust CO emission rate.
---------------------------------------------------------------------------

    \23\ Stoichiometry is the theoretical air-fuel ratio (AFR) for 
complete combustion and is the theoretical point for nearly the 
lowest amount of CO production. AFR associated with stoichiometry 
for typical gasoline formulations is nominally 14.6.
    \24\ A dynamometer is an instrument that measures the power 
output of an engine.
---------------------------------------------------------------------------

    CES's testing in accordance with EPA test procedures showed that 
the prototype engine, while mounted on a dynamometer and equipped with 
the muffler that had a catalyst installed, had a 6.0 g/kW-hr CO 
emission rate. This CO emission rate is 99 percent below the EPA's 
Phase 2 and Phase 3 CO standard of 610 g/kW-hr.\25\ The prototype 
engine had an HC+NOX exhaust emission rate of 6.7 g/kW-hr. 
This rate is 45 percent below the EPA's Phase 2 HC+NOX 
standard for a Class II engine, to which the engine was originally 
certified, and 16 percent below the Phase 3 HC+NOX standard 
that came into effect shortly after CPSC's development program with UA 
began. CES's dynamometer testing also showed that the prototype engine 
delivered a maximum power of 7.9 kW, which is within 0.3 kW of the 
advertised rated power for the unmodified OEM carbureted engine. CES's 
emission testing of the prototype generator (with the engine still 
installed in the generator, as opposed to mounted on the dynamometer) 
measured a weighted CO emission rate of 26.10 g/hr.\26\ Thus, at the 
end of the engine's rated useful life, the prototype engine's emissions 
met both EPA's Phase 2 requirements for HC+NOX and CPSC 
staff's target reduction for the exhaust CO emission rate. Staff's 
prototype findings have since been repeated by others who patterned 
their reduced CO emissions prototype generators on the design concept 
developed for CPSC by the University of Alabama.\27\ Moreover, new 
generator products with reduced CO emissions, achieved by similar 
engine design modifications and use of catalysts, are beginning to 
enter the retail market.\28\
---------------------------------------------------------------------------

    \25\ The EPA sets emission standards for all small SI engines. 
These engines provide power for a wide range of products typically 
owned by consumers, including portable generators. The EPA's primary 
emphasis is on regulating emissions that contribute significantly to 
nonattainment of the National Ambient Air Quality Standards (NAAQS) 
for ozone, of which hydrocarbons and oxides of nitrogen 
(HC+NOX) are precursors. For non-handheld engines, the 
EPA adopted emission standards referred to as Phase1 in 1995, Phase 
2 in 1999, and Phase 3 in 2008.
    \26\ The highest of three tests was 26.10 g/hr. The other two 
tests yielded weighted CO rates of 23.47 and 19.38 g/hr.
    \27\ See Techtronic Industries (TTi) presentation on 3/17/16, at 
PGMA's Technical Summit on Carbon Monoxide Hazard Mitigation for 
Portable Generators--pages 85-105 of 178 page pdf file at: http://www.cpsc.gov//Global/Newsroom/FOIA/Meeting%20Logs/2016/MeetingLogPGMA31716.pdf.
    \28\ See Tab I staff's briefing package.
---------------------------------------------------------------------------

Part Two: Comparative Testing of Unmodified Carbureted (Baseline) and 
Prototype Generators at National Institute for Standards and Technology
    The Commission entered into an interagency agreement with NIST to 
conduct the second part of the program. In this part of the 
demonstration program, NIST operated one generator in its unmodified 
carbureted configuration and another generator in the prototype 
configuration in the attached garage of a test house on NIST's campus. 
The test house is used for conducting indoor air quality (IAQ) studies. 
NIST measured the CO accumulation in the garage and transport into the 
house. The results provide a sense of how quickly a commonly fatal 
consumer scenario develops with an existing carbureted generator, and 
what the comparative results are from the same tests with the fuel-
injected catalyzed prototype.\29\
---------------------------------------------------------------------------

    \29\ Another objective of the IAG was to determine each 
generator's mass CO emission rates at each of the six loads used in 
the load profile. This work also supported NIST's validation of 
NIST's multizone airflow and contaminant transport model CONTAM, 
which is used to predict contaminant concentrations throughout a 
modeled structure resulting from a source mass emission rate located 
somewhere within the structure. NIST used CONTAM in predicting the 
health effects of the CO rates associated with the proposed 
performance requirements.
---------------------------------------------------------------------------

    NIST compared the garage CO concentrations from the prototype and 
the unmodified carbureted generator, after equal periods of generator 
run-time in the tests, with the garage bay door fully closed. NIST 
found that the prototype showed 97 percent reduction in the amount of 
CO released into the garage, compared to the unmodified carbureted 
generator. This reduction is consistent with UA's findings and 
translated to much lower levels of CO transporting throughout the 
house. Taking into consideration the CO time course profile (which is 
the CO concentration over time) of each room of the house and of the 
garage, the Commission performed health effects modeling and estimated 
that the prototype generator resulted in a significantly extended time 
interval for hypothetical occupants to escape or to be rescued before 
being incapacitated. For example, in one test in which the garage bay 
door and connecting door to the house were both closed, the time 
interval increased by a factor of 12 with the prototype, compared to 
the unmodified carbureted generator (from 8 minutes to 96 minutes) for 
the deadly scenario of a consumer in the garage with the generator. The 
time interval increased even more for occupants inside the house.
    The Commission believes that this increased time interval could 
give occupants an opportunity to remove themselves from the exposure 
before being incapacitated (perhaps due to their symptoms or other 
reasons such as an unrelated need to leave the house) or to be found 
alive by others. In contrast, the Commission predicts that the high CO 
emission rate of the unmodified carbureted generator would cause some 
of the occupants, depending on where they are located, to experience 
relatively quick onset of confusion, loss of muscular coordination, 
loss of consciousness, and death, without having first experienced 
milder CO poisoning symptoms associated with low or slowly rising CO-
induced hypoxia.

B. Staff Assessment of Feasible CO Rates Based Upon EPA's Technology 
Demonstration Program and Staff Testing of Fuel-Injected Generators

    A technology demonstration conducted by EPA further demonstrates 
the feasibility of significantly lowering CO emission generators using 
EFI.\30\ In

[[Page 83566]]

2006, EPA examined the feasibility of reducing HC+NOX 
emissions beyond their Phase 2 standards.\31\ EPA applied EFI and high-
efficiency catalysts on two single-cylinder, air-cooled engines, both 
nominally 500 cubic centimeters (cc) in displacement with overhead 
valve (OHV) configurations. Because CO and NOX emissions 
have an inverse relationship, in focusing on reducing HC+NOX 
emissions, EPA specifically chose to test with catalysts formulations 
designed to minimize CO oxidation.\32\
---------------------------------------------------------------------------

    \30\ McDonald, Joseph, Olson B, and Murawski M, Demonstration of 
Advanced Emission Controls for Nonroad SI Class II Engines, SAE 
paper 2009-01-1899; McDonald, Joseph, Memorandum, Re: Supplemental 
Engine Dynamometer Data, May 5, 2006. (available online in: 
www.regulations.gov in docket identification EPA-HQ-OAR-2004-0008-
0372.).
    \31\ U.S. EPA, Control of Emissions from Marine SI and Small SI 
Engines, Vessels, and Equipment--Final Regulatory Impact Analysis, 
EPA420-R-08-014, September 2008 (available online in 
www.regulations.gov in docket identification EPA-HQ-OAR-2004-0008-
0929); U.S. EPA, EPA Technical Study on the Safety of Emission 
Controls for Nonroad Spark-Ignition Engines <50 Horsepower, EPA420-
R-06-006, March 2006, Docket Identification EPA-HQ-OAR-2004-0008-
0333. (available online at: (http://www.epa.gov/nonroad/equip-ld/phase3/420r06006-rpt-2appdx.pdf).
    \32\ Oxidation of CO to carbon dioxide (CO2) is the 
means by which CO emissions are reduced in a catalyst.
---------------------------------------------------------------------------

    EPA used low-cost engine management and fuel injection systems that 
were similar to that which UA used for the CPSC prototype generator. 
While the UA generator prototype used a closed-loop system and tuned 
the fuel to stoichiometry at the high loads, in interest of cost-
savings, the EPA engines did not use an oxygen sensor necessary to make 
it a closed-loop fuel system. For its engines, EPA replaced the 
carburetor with open-loop EFI that was calibrated rich of 
stoichiometry, i.e., a lower air-to-fuel ratio, at moderate-to-high 
loads and near stoichiometry at light load conditions to achieve the 
desired emission control of HC+NOX. EPA developed integrated 
catalyst-muffler systems for its engines, all selected to prioritize 
NOX reduction and HC oxidation over CO oxidation. Even 
though EPA was intentionally trying to select catalysts that would 
minimize CO oxidation, both engines achieved an average 68 percent 
reduction in the weighted CO emission rate. The average of the weighted 
CO emission rate of the two carbureted OEM configurations was 1,760 g/
hr, and the average of the two EFI configurations with the catalyst 
providing the most reduction in CO emissions was 565 g/hr.
    Although the EPA noted that some engines may need improvements to 
accommodate stoichiometric fuel control (such as redesign of cooling 
fins, fan design, combustion chamber design, and a pressurized oil lube 
system), EPA concluded that closed-loop EFI with fuel control at or 
near stoichiometry is technically feasible and is not cost prohibitive 
on all Class II engines.\33\
---------------------------------------------------------------------------

    \33\ U.S. EPA, EPA Technical Study on the Safety of Emission 
Controls for Nonroad Spark-Ignition Engines <50 Horsepower, EPA420-
R-06-006, March 2006, Docket Identification EPA-HQ-OAR-2004-0008-
0333. (available online at: (http://www.epa.gov/nonroad/equip-ld/phase3/420r06006-rpt-2appdx.pdf).
---------------------------------------------------------------------------

    CPSC staff believes that with a focus on reducing CO emissions, a 
lower weighted CO emission rate could have been achieved by using an 
oxygen sensor for closed-loop feedback, operation closer to 
stoichiometric at the higher loads, and a different catalyst formulated 
for higher conversion efficiency of CO.\34\
---------------------------------------------------------------------------

    \34\ See CPSC staff's briefing memorandum and Tab I of the 
briefing package for a more detailed explanation.
---------------------------------------------------------------------------

    CPSC staff tested three fuel-injected generators created by three 
different manufacturers.\35\ Two of these generators, neither of which 
was designed for low CO emissions, are available in the marketplace, 
and the third is a manufacturer's prototype generator that was designed 
for low CO emissions. The first of the three generators is a 10.5 kW 
rated generator powered by a twin-cylinder Class II engine with nominal 
700 cc displacement and overhead valve (OHV) configuration. The 
generator does not have a catalyst for aftertreatment and the 
generator's engine is calibrated rich of stoichiometry at higher loads 
and at stoichiometry with closed-loop fuel control at moderate-to-light 
load conditions. Based on CPSC staff's testing of this generator in 
normal atmospheric oxygen, which found a 670 g/hr weighted CO emission 
rate, as well as on staff's engineering assessment of its physical and 
operational characteristics, staff believes that it is reasonable to 
expect that this engine could operate closer to stoichiometric at the 
higher loads and that a catalyst formulated for some CO conversion 
efficiency could be used for aftertreatment to further reduce its CO 
emission rate to nominally 200 g/hr.
---------------------------------------------------------------------------

    \35\ See Tab I of the staff's briefing package.
---------------------------------------------------------------------------

    The second generator is a 5.5 kW rated power generator powered by a 
single-cylinder Class II engine with nominal 400 cc displacement and 
OHV configuration, equipped with an oxygen sensor for some form of 
partial closed-loop operation and a catalyst. The engine is calibrated 
rich of stoichiometry at all loads. Based on staff's testing in normal 
atmospheric oxygen that found a nominal weighted CO rate of 560 g/hr, 
staff believes a CO emission rate of nominally 100 g/hr is possible, if 
the generator were operated closer to stoichiometric for at least some 
of the loads and used a catalyst formulated for higher CO conversion 
efficiency.
    The third generator is a 5.5 kW rated power generator powered by a 
closed-loop fuel-injected single-cylinder Class II engine with nominal 
400 cc displacement and OHV configuration. It has a catalyst for 
aftertreatment and the engine is calibrated to stoichiometric AFR with 
closed-loop operation at all loads. Staff's testing of this generator 
in normal atmospheric oxygen found a weighted CO rate of 81 g/hr.

C. Assessment of Epidemiological Benefits of Reduced CO Emission 
Portable Generators--NIST CO and COHb Modeling Study

1. Background
    To assess the epidemiological benefits of reduced CO emission 
generators, CPSC contracted NIST to perform a series of CO exposure 
simulations that would model the operation of a portable generator in 
various locations within various house configurations and other 
structures, and at various CO emission rates.\36\ CPSC used these 
results to determine the possible deaths averted if reduced CO emission 
generators had been used, as described below.
---------------------------------------------------------------------------

    \36\ Emmerich, Steven J., B. Polidoro, W. Dols, Simulation of 
Residential CO Exposure Due to Portable Generator Operation in 
Enclosed Spaces (NIST Technical Note 1925), 2016.
---------------------------------------------------------------------------

2. CO Emission Modeling
    NIST modeled 40 different structures, including houses with 
basements and others with crawlspaces, as well as ones with slab-on-
ground construction, with and without attached garages, and including 
older construction and newer construction homes. Three different 
external residential structures designed to represent detached garages 
and sheds were included in the 40 structures. The 37 different house 
models included detached home, attached home, and manufactured home 
designs. House models and other structures used in the modeling study 
were matched to 503 out of the 659 actual generator-related CO 
fatalities reported to CPSC over the period 2004 to 2012. One hundred 
fifty-six fatalities (659 minus 503) were not included in the modeling 
analysis because the generator was either outdoors or in a structure 
such as a camper, RV, tent, church, boat, or apartment complex that was 
not similar to any of the structure models used by NIST. The Commission 
believes that reduced emission generator use in these scenarios would 
most likely have produced fewer CO fatalities than the number observed 
in the incident data.

[[Page 83567]]

This would be especially true in scenarios with the generator running 
outdoors, or in a large-volume space, such as a church.
    CPSC staff chose the modeled CO emission rates based on: (1) CPSC's 
estimates of elevated CO emission rates expected for the four 
categories of current carbureted generator products when operating in a 
reduced oxygen environment, and (2) a series of reduced CO generation 
rates that allowed CPSC to assess benefits and costs of various levels 
of reduced emissions within technically feasible rates for each 
generator category.
    The first part of the modeling study used the NIST multizone 
airflow and contaminant transport model CONTAM, which predicted CO 
levels in different areas of each structure, over a 24-hour period.
Determination of CO Emission Rates, Run Times, and Heat-Release Rates 
for Carbureted Generators
    Staff determined CO emission rates, run times, and heat release 
rates for NIST to model for current, carbureted generators (baseline 
carbureted generators) based on data from EPA's non-road small spark-
ignition engine (NRSI) certification data Web site and advertised power 
ratings and engine specifications for representative products. These 
baseline parameters are shown in Table 4, and an explanation of the 
basis for the parameters follows.

    Table 4--Modeled CO Emission Rates, Run Times, and Heat-Release Rates for Baseline Carbureted Generators
----------------------------------------------------------------------------------------------------------------
                                                                      Average
                                                                   weighted  CO    Average  run    Average heat
                       Generator category                          rate at  17%     time (hrs)      rlease rate
                                                                     O2 (g/hr)                         (kW)
----------------------------------------------------------------------------------------------------------------
Handheld........................................................             900               8               2
Class 1.........................................................           1,800               9               6
Class 2 Single Cylinder.........................................           4,700              10              13
Class 2 Twin Cylinder...........................................           9,100               9              25
----------------------------------------------------------------------------------------------------------------

    To determine values for CO emission rates, run times, and heat-
release rates representative of current generators involved in the 
fatal incidents, staff considered the generators produced by six large 
generator manufacturers. All of these manufacturers are members of the 
Portable Generator Manufacturers Association (PGMA), and, as documented 
on PGMA's Web site, are the major manufacturers of portable generators 
sold in North America and a significant majority of the industry.'' 
\37\ Staff used the manufacturers' reported product specifications for 
31 generators ranging from 900 to 15,000 watts rated power and 
developed the representative parameters for each of these inputs based 
on the range of generators in each of the four categories in Table 4.
---------------------------------------------------------------------------

    \37\ www.pgmaonline.com.
---------------------------------------------------------------------------

    Staff used the engine specifications provided by the generator 
manufacturer to search the EPA's NRSI engine certification data Web 
site to find the published CO emission rate corresponding to each 
generator's engine. Staff then calculated the weighted CO emission rate 
(in g/hr) for each generator's engine, by multiplying the g/kW-hr rate 
by 46.7 percent of the maximum engine power (46.7 percent of the 
maximum engine power is the weighted average based on the EPA six-mode 
calculations).\38\ Staff assumes that the typical load profile of a 
portable generator used by a consumer is that of the weighted profile. 
In addition, staff assumes the engine's weighted CO rate is that of the 
generator.
---------------------------------------------------------------------------

    \38\ The engine manufacturer's CO emission rate reported in the 
EPA's exhaust emission certification Web site, in terms of grams per 
kilowatt-hour (g/kW-hr), is the sum of six weighted CO rates in 
grams per hour (g/hr) that the engine emits while installed on a 
dynamometer test platform and operating with each of six steady-
state loads applied (also referred to as modes) divided by the sum 
of the weighted power for those six modes. The EPA's six-mode test 
cycle was developed with industry to replicate typical in-use 
operation of small utility engines when used in all types of engine-
driven products.
---------------------------------------------------------------------------

    Considering that 95 percent of the generator-related CO fatalities 
in CPSC's databases occurred when the generator was operated in an 
enclosed space, it is important for modeling studies to consider the CO 
emission rate when a carbureted generator is operating in such enclosed 
space scenarios. Evidence supporting this view is seen in results of 
findings from generator tests conducted by NIST under a prior 
interagency agreement with CPSC.\39\ NIST's tests, as well as 
subsequent staff testing, showed that the CO emission rate of current 
carbureted generators increases threefold as the oxygen drops from 
normal levels (approximately 20.9 percent oxygen) to approximately 17 
to 18 percent oxygen when a generator is operated in an enclosed space, 
such as those reported in the incident data. Consequently, to reflect 
more accurately current carbureted generator operation under oxygen 
depletion conditions, staff's calculated weighted CO emission rate, 
when each generator is operated outdoors at normal oxygen, was 
multiplied by a factor of 3.
---------------------------------------------------------------------------

    \39\ Emmerich, S.J., A. Persily, and L. Wang, Modeling and 
Measuring the Effects of Portable Gasoline-Powered Generator Exhaust 
on Indoor Carbon Monoxide Level (NIST Technical Note 1781), Feb 
2013.
---------------------------------------------------------------------------

    The generators' run time on a full tank of gas that was associated 
with 50 percent of the advertised rated load was used to determine the 
full-tank run time used in the modeling. Fifty percent load was used 
because, as stated above, 46.7 percent of the engine's maximum power 
represents the weighted load profile, which is nominally 50 percent. 
Staff generally used manufacturer's product specifications for run time 
at 50 percent load, and in a few cases, used engineering estimates to 
determine the run times. Staff chose to model run times based on a full 
tank of fuel as a conservative assumption, despite knowledge of 
scenarios where a generator was used to allow completion of a specific 
short-duration task, in temporary power outage situations where power 
was restored within a few hours before a full tank of fuel could be 
consumed, or in scenarios where the generator was still running when 
victims were found, had summoned help, and/or had removed themselves 
from the area.
    Staff estimated heat-release rates for these generators based on 
the fuel-consumption rate at 50 percent load, the manufacturer's 
specification for the generator's tank capacity, a heat of combustion 
of gasoline of 42.5 MJ/kg, and an assumed conservative 35 percent 
thermal efficiency of the engine.

[[Page 83568]]

Determination of CO Emission Rates, Run Times, and Heat Release Rates, 
for Reduced Emission Rate Portable Generators
    NIST used the same values for run times and heat-release rates for 
the reduced CO emission rates of each generator category as those used 
for current generators.\40\ NIST modeled the rates of 50, 125, 250, 
500, 1,000 and 2,000g/hr. The three lowest of these approximates the 
range of CO emission rates that staff believes are technically feasible 
for both the handheld and class 1 generator categories (50 g/hr), class 
2 single-cylinder category (100 g/hr), and class 2 twin-cylinder 
category (200 g/hr) in ambient air with normal atmospheric oxygen.
---------------------------------------------------------------------------

    \40\ CPSC staff reasons that an additional weight and volume of 
the emission control components needed to reduce the CO emission 
rate, could be offset by a smaller fuel tank and due to the improved 
fuel efficiency of reduced emission engines, the smaller tank would 
still be able to maintain similar run times to carbureted units with 
larger fuel tanks.
---------------------------------------------------------------------------

Weather, Temperature and CO Rate Parameters for Carbureted and Reduced 
CO Emission Generators
    Simulations were run for each model structure and model generator 
location for 28 representative weather days to determine the CO time 
course profiles, which are the minute-by-minute CO concentration levels 
in each of the various rooms of the house. The 28 weather days were 
chosen to include 14 cold weather days (Detroit, MI), seven weather 
days from warm months (Miami, FL) and seven transition months weather 
days (Columbus, OH) to represent the distribution of fatalities, which 
has been seen to skew towards cold-weather days in a similar 
manner.\41\ Starting indoor temperatures were assumed to be 23 [deg]C 
in all rooms, and temperatures were modeled to change within the rooms, 
based on heat transfer related to the heat release from the generator. 
Thus, generators of various sizes were modeled to be running on 28 
different weather days for a full-tank run time \42\ in various rooms 
within each of the structures, with run times and heat-release rates 
appropriate to that size of generator, and emissions based on current 
carbureted generators, or based on possible reduced-emission generators 
for comparison. In the modeling of baseline carbureted generators, to 
simulate the increasing CO emission rate as the oxygen level drops in 
the space the generator is operating (and thus, a lower CO emission 
rate at the beginning of operation than later), NIST modeled CO rates 
for the first 2 hours of operation that were only two-thirds of the 
rates shown in Table 4. After 2 hours, the CO rates were increased to 
the rates in Table 4 for the duration of the run time. In contrast, as 
another conservative assumption, NIST modeled reduced CO emission rates 
as constant rates for the entire respective generator run time. The 
results of the models provided CO time-course profiles for each room of 
each structure on each weather day for each generator type and location 
and emission rate.
---------------------------------------------------------------------------

    \41\ The 28 individual days were selected using historic weather 
data recorded at three different geographic locations and three 
different temperature ranges to approximate the distribution of 
incidents observed in the CPSC incident data at a generalized level. 
Although the weather days may be consecutive (e.g., 14 consecutive 
cold weather days), there was no carry-over effect from one day to 
the next. Each day modeled was reset to zero CO. Therefore, each 
day, from a CO standpoint, was an independent event.
    \42\ NIST also modeled half-tank run times to simulate scenarios 
where shorter duration were considered more appropriate (e.g., in 
scenarios in which the generator was being used to allow completion 
of a specific short-duration task at an unpowered location, in 
temporary power outage situations, where power was restored within a 
few hours before a full tank of fuel could be consumed, or in 
scenarios where the generator was still running when victims were 
found, had summoned help, and/or had removed themselves from the 
area). While staff has these modeling results, staff only analyzed 
the modeling results for the full-tank run times to estimate those 
benefits so as to be consistent with a conservative estimate of 
benefits.
---------------------------------------------------------------------------

3. Application of COHb Modeling
    The second part of the modeling study used the CONTAM-generated CO 
time course profiles as input values to predict corresponding COHb 
levels expected in healthy adults, as a function of time, using Coburn 
Forster Kane (CFK) modeling.\43\ Conservative assumptions were made 
about respiratory rates, given expected activity rates over the 24-
hours of modeled exposure. The respiratory minute volume (RMV), 
expressed in liters per minute (L/min), is the specific inhalation rate 
input value used in the CFK, and for the epidemiological benefits 
calculated in this analysis, staff used an RMV of 10 L/min. Staff's use 
of a constant 10 L/min RMV for light activity likely overestimates the 
breathing rate (and CO uptake rate) of a significant number of victims. 
In the majority of fatal incidents, victims were at home during an 
unplanned power outage, or an outage due to utility shut off, and there 
was no indication that they had engaged in more than sedentary-to-light 
activity levels for most of the time. For example, in several of these 
cases, a generator was first started in an enclosed space late in the 
evening/night at a time where victims were clearly preparing for/or 
retired to bed; in these instances, a sedentary/resting activity level 
of 6 L/min RMV would be more appropriate. Thus, use of an RMV of 10 L/
min is another conservative assumption in the analysis. This is 
explained in more detail in Tab K of staff's briefing package and its 
appendix.
---------------------------------------------------------------------------

    \43\ The CFK modeling is a nonlinear differential equation that 
is a physiologically based mechanistic model for predicting CO 
uptake and COHb formation and elimination in humans; it has been 
validated by empirical data from human studies and is widely 
regarded by authoritative sources as a reasonably reliable and 
broadly applicable COHb model for acute exposures.
---------------------------------------------------------------------------

    To assess the impact of low-emission generators on potential 
reductions in CO fatalities, the number of observed fatalities from the 
incident data were assigned to one of the model structures. The initial 
step was to assign the fatalities that occurred in an ``exact match'' 
structure type. ``Exact match'' structures are defined as those that 
match all of the NIST structure characteristic parameters used in the 
analysis to describe the structure, such as floor area, number of 
floors, existence of a garage and/or basement. Where exact matches 
could not be assigned, fatalities were apportioned among best matching 
structure types (those matching the most number of NIST parameters).
    These simulations included various generator location scenarios, 
dependent on house/structure model designs (i.e., only models that had 
a basement included the generator-in-basement scenario; and only models 
that had an attached garage included the generator-in-the-attached 
garage scenario). To match, as closely as possible, actual usage 
patterns, the simulation results of the generator locations within the 
house/structure were proportionately equal to those observed in the 
incident data.
    The victim's location in the modeled house is assumed to have equal 
probability of occurring in any living space room. This assumption was 
made for three reasons. In multi-fatality incidents, victims were often 
found in different locations within a house. In many cases, the 
victim's location could not be determined from available reports. 
Moreover, it was frequently unclear whether victims were located in a 
single area in which they were found for the entire time or if the 
individual moved around through various parts of the structure. An 
example of the latter case could be that an individual felt sick and 
moved, perhaps, to a bedroom to lie down before expiring.
    Next, CPSC staff incorporated criteria that staff developed to 
evaluate modeled COHb profiles considered indicative of

[[Page 83569]]

fatal versus nonfatal outcomes. CPSC's Health Sciences (HS) staff 
developed four ``COHb Analysis Criteria'' to assess whether predicted 
COHb profiles from modeled residential scenarios were likely indicative 
of fatal or nonfatal CO exposures in average adults.\44\ Where a fatal 
outcome is predicted, the criteria can be used to assess the predicted 
time to reach fatal exposure during a 24 hour modeling period for each 
simulated CO exposure. The criteria are intended to reflect the fact 
that lethal CO health effects are not simply a function of acute 
hypoxia resulting from a critical reduction in blood levels of oxygen 
delivered to tissues, as indicated by attainment of a specific peak 
COHb level.\45\ The criteria include some consideration of the level 
and duration of the predicted COHb elevation, which recognizes that, in 
addition to reducing oxygen delivery to tissues, CO can enter the non-
vascular body compartment and adversely impact important cellular 
functions by displacing oxygen from various intracellular heme proteins 
(particularly myoglobin proteins found predominantly in cardiac and 
skeletal muscles, and certain cytochrome P-450 enzymes involved is 
cellular respiration). In some prolonged CO elevations, the additional 
nonvascular adverse effects of CO can result in death at COHb levels 
that are not typically lethal.
---------------------------------------------------------------------------

    \44\ See Tab K and Tab K appendices of staff's briefing 
memorandum.
    \45\ Oxygen binding sites of hemoglobin molecules have more than 
200-fold higher affinity for CO than for oxygen.
---------------------------------------------------------------------------

    Although the relationship is not absolute, physiological, 
epidemiological, and clinical studies provide evidence that acute CO 
poisoning effects in healthy adults tend to follow toxicological dose-
response principles, and that risk of more serious adverse CO poisoning 
effects worsen progressively as blood levels of COHb increase.\46\ 
However, it is clear that lethal CO exposures cannot be defined simply 
by attainment of a single COHb level. Staff used several information 
sources to develop COHb assessment criteria to facilitate calculation 
of benefits estimates predicted for generators with reduced CO 
emissions. A recent authoritative review of CO toxicity by the Agency 
for Toxic Substances and Disease Registry indicates that there is a 
high risk of lethal outcome once COHb levels have reached a critical 
window, which, for healthy individuals, is generally considered to lie 
between 40 percent and 60 percent COHb.\47\ HS staff reviewed 
information on COHb levels of victims who experienced acute, generator-
related CO poisoning; COHb levels documented in fatal CO poisoning 
cases reported to CPSC were compared with COHb levels reported for a 
select group of survivors who received hyperbaric oxygen treatment 
(HBO-T) for generator-related CO poisoning injuries considered to be of 
high severity. Staff also considered information on fatal and nonfatal 
COHb levels reported in non-fire-related CO poisoning cases that did 
not specifically involve generator-related CO exposures. Based on 
review of available data on COHb levels in fatal and nonfatal 
generator-related CO exposures, and other non-generator, non-fire 
related CO deaths and injuries, staff developed the following criteria 
to distinguish between modeled COHb levels indicative of lethal versus 
nonlethal outcome:
---------------------------------------------------------------------------

    \46\ For example, loss of consciousness is not generally 
expected in average adults if peak COHb levels remain below 20 
percent, but becomes increasingly more likely as levels approach, 
and exceed, 40 percent COHb. (Note: Staff is referring to the acute 
COHb blood levels actually reached, or predicted by modeling, which 
is not necessarily the same as the highest measured COHb levels 
reported in clinical cases, where initial COHb measurements are 
typically reduced from peak levels attained, primarily due to the 
time lag between the end of CO exposure and blood sampling, plus use 
of supplemental oxygen during this interval).
    \47\ Agency for Toxic Substances and Disease Registry (ATSDR), 
(June 2012) Toxicological Profile for carbon monoxide (web link: 
http://www.atsdr.cdc.gov/toxprofiles/tp201.pdf.
---------------------------------------------------------------------------

    (1) If peak level is >=60% COHb, assume death.
    (2) If peak level is >=50% COHb but <60%, assume death unless 
average duration of elevation >50% COHb is less than 2 hours, and 
average duration of elevation between >=40% and <50% COHb is less than 
4 hours.
    (3) If peak level is >=40% COHb, but <50% COHb, assume death if 
duration of the average in this range exceeds 6 hours.
    (4) If peak level is <=40% COHb, assume survival.
4. Determination of Deaths Averted
    The final part of the modeling study used patterns evident in fatal 
incident data (such as the known percentages of deaths related to 
various generator locations for various generator sizes and structure 
types) to modulate the modeled COHb data to estimate the number of 
fatal CO exposures reported for each generator category that could have 
been averted at each reduced emission rate. The modeling included 
exposure duration of up to 24 hours, estimated on a minute-by-minute 
resolution, and determined the status of living versus dead for modeled 
occupants at each minute in time. The model assumed equal probabilities 
of intervention over a 24-hour period. This assumption was used because 
frequently, one could not determine from the incident data how long of 
an interval between when the generator was started and when the victim 
died or some other type of intervention occurred.
    Although CPSC incident data reflect primarily fatal CO incidents, 
the assumption that surviving people eventually depart the exposure is 
supported by staff's estimates of at least 25,400 medically attended CO 
injuries involving generators over the period of the deaths modeled and 
the fact that in some fatal incidents, there were surviving victims. 
For each scenario (CO emission rate, structure model, generator 
location, occupied zone, weather day), the model produced estimated 
COHb levels. From these COHb levels, staff determined at each minute 
interval, whether the victim was dead or alive, based on the criteria 
outlined above. The average per-minute interval over the 28 days 
produced a probability of fatality at the given time. Under the 
assumption of equal probability of intervention over the 24-hour 
period, the average probability of fatality over the 24-hour period is 
the overall fatality rate for the given scenario. For the current 
carbureted generator model simulation, the probability was normalized 
(scaled up) to 100 percent of the allocated deaths because this is 
based on the actual incident data. The reduced emission rate simulation 
results were scaled up by the same factor to normalize the data. The 
difference between the allocated deaths per scenario and the number 
estimated for the reduced emission levels is the estimate of the deaths 
averted for the specified scenario. The summation of all the modeled 
scenarios (at a given emission level) represents an estimate of the 
potential deaths averted, if a reduced emission level generator had 
been in use in place of the current carbureted types. Thus, the same 
scenarios and assumptions were used for each generator size, generator 
location, structure, and weather day combination for current and 
reduced emissions generators so that the comparison was consistent and 
the assumptions would apply in the same way to current and reduced 
emissions.
    Table 5 presents a summary of the number of deaths that potentially 
could have been averted over the 2004 to 2012 time span, if low-
emission generators were used in place of the high CO output generators 
that were in use during this period. CPSC staff estimates that a total 
of 208 out of 503 deaths

[[Page 83570]]

could have been averted. CPSC staff realizes there is uncertainty 
associated with this estimate given the assumptions and estimations 
staff used in developing this estimate. However, CPSC staff used 
conservative values and believes the uncertainty in the estimate is 
within the range of the sensitivity analysis that staff performed on 
the effectiveness of the emission rates, as described in the 
preliminary regulatory analysis.

 Table 5--Summary of Potential Deaths Averted at Technically Feasible CO Emission Rates in Reduced Oxygen, 2004-
                                                      2012
----------------------------------------------------------------------------------------------------------------
                                                   CO emission
                                                      rate *
                                                    simulating        Actual         Potential       Potential
               Generator category                   generator       fatalities        deaths        lives saved
                                                   operation in    allocated by       averted        rate  (%)
                                                   an enclosed         class
                                                      space
----------------------------------------------------------------------------------------------------------------
Handheld.......................................              150             3.7             1.7            46.6
Class 1........................................              150           176.2            87.7            49.7
Class 2 Single Cylinder........................              300           321.3           117.9            36.7
Class 2 Twin Cylinder..........................              600             1.8             0.3            17.2
                                                ----------------------------------------------------------------
    Total......................................  ...............           503.0    207.6 = ~208            41.3
----------------------------------------------------------------------------------------------------------------
* These rates are 3 times the technically feasible rates at normal ambient oxygen (~20.9%) to account for CO
  emission rate increase in reduced oxygen. To account for production variation the CO emission rates in the
  proposed requirements are 1.5 times the technically feasible rate in normal oxygen.

The numbers are based on the conservative assumption of CO emission 
rates tripling from technically feasible rates in normal oxygen for 
each generator category when operating in theorized oxygen depletion. 
Staff tripled the rates because staff determined that in reduced oxygen 
levels, the emission rates of generators that meet the technically 
feasible rates in ambient air may increase. This factor of 3 is based 
on testing of carbureted generators conducted by NIST \48\ and CPSC 
staff.\49\ However, test results from NIST \50\ indicate that the EFI 
generator depleted the oxygen significantly less than the carbureted 
generator when tested in each matched pair identical test scenario. 
Furthermore, based on staff's testing of three generators with fuel-
injected engines having different degrees of closed-loop operation, 
staff believes the factor of increase when the oxygen is 17 percent may 
be less than 3 for some generators that use closed-loop EFI.\51\ 
Therefore, based on both of these issues, the factor of 3 could likely 
overstate the weighted CO emission rates for some EFI generators when 
operated indoors, and understate the reduction in deaths and injuries 
resulting from the proposed standard. Consequently, staff believes that 
the assumption of a threefold increase in the technically feasible 
rates in ambient oxygen is an appropriate assumption to model, 
conservatively, for generators operating in enclosed space. Thus, staff 
ultimately determined epidemiological benefits overall, based on 
emission rates of 150, 300, and 600 g/hr technically feasible rates, as 
shown in Table 5.
---------------------------------------------------------------------------

    \48\ Emmerich SJ, Polidoro, B, Dols WS. Simulation of 
Residential CO Exposure Due to Indoor Portable Generator Operation, 
NIST Technical Note 1925, 2016.
    \49\ See Tab J in the staff's briefing package.
    \50\ Buyer J. Technology demonstration of a Prototype Low Carbon 
Monoxide Emission Portable Generator. U.S. Consumer Product Safety 
Commission, Bethesda, MD, September 2012.
    \51\ Tab J of staff's briefing package.
---------------------------------------------------------------------------

    Staff expects that some additional, but unquantified deaths, could 
be averted in the remaining 24 percent of fatalities that were not 
modeled, especially in fatal incidents where a generator was operated 
outdoors, and/or, that had co-exposed survivors. Staff's 
epidemiological benefits analysis is contained in TAB K of the staff's 
briefing package.

VII. Relevant Existing Standards

A. Portable Generator Label

    On January 4, 2007, the CPSC voted unanimously (2-0) to require 
manufacturers of portable generators to warn consumers of carbon 
monoxide (CO) hazards through a mandatory label containing performance 
and technical data related to the performance and safety of portable 
generators. The required warning label informs purchasers: ``Using a 
generator indoors CAN KILL YOU IN MINUTES''; ``Generator exhaust 
contains carbon monoxide. This is a poison you cannot see or smell''; 
``NEVER use inside a home or garage, EVEN IF doors and windows are 
open''; ``Only use OUTSIDE and far away from windows, doors, and 
vents.'' The label also includes pictograms. The label requirement went 
into effect on May 14, 2007, and is required for any portable generator 
manufactured or imported after that date.\52\ Although the Commission 
believes that the mandatory label for portable generators might prevent 
some incidents of CO poisoning and death, as discussed in more detail 
in Section VIII of this preamble, evidence suggests that labeling alone 
is not sufficient to address the CO poisoning hazard, and that 
performance requirements for portable generators are needed.
---------------------------------------------------------------------------

    \52\ 16 CFR part 1407.
---------------------------------------------------------------------------

B. Voluntary Standards

    Underwriters' Laboratories Inc. (UL) and the PGMA have each been 
accredited by the American National Standards Institute (ANSI) to 
develop a U.S. safety standard for portable generators. However, only 
PGMA has developed an ANSI standard for portable generators, ANSI/PMGA 
G300-2015. UL has also developed a standard, UL 2201, which has not 
become an ANSI standard, due to lack of consensus. International 
Organization for Standardization (ISO) 8528-13:2016, Reciprocating 
Internal Combustion Engine Driven Alternating Current Generating Sets--
Part 13: Safety, is a standard applicable to portable generators sold 
overseas.
1. UL 2201
    In 2002, UL formed a standards technical panel (STP) to develop the 
first voluntary standard in the United States, dedicated solely to 
portable generators, UL 2201 Safety Standard for Portable Generator 
Assemblies. CPSC technical staff joined the STP for UL 2201 at its 
inception and has been an active participant with a long record of

[[Page 83571]]

advocating that the standard address CO poisonings.
    The requirements in UL 2201 cover internal combustion engine-driven 
generators rated 15 kW or less, 250 V or less, which are provided only 
with receptacle outlets for the AC output circuits. The scope section 
of UL 2201 states that the standard addresses: ``the electric shock, 
fire, and casualty aspects associated with the mechanical performance 
and the electrical features of portable engine-driven generator 
assemblies.'' The standard restates the mandatory CPSC label 
requirement, but the standard does not otherwise address the risks 
related to CO poisoning. UL 2201 includes construction requirements to 
define minimum acceptability of components of the fuel system, engine, 
alternator, output wiring and devices, frame/enclosures and others, to 
ensure their suitability in this application to mitigate the risk of 
shock, fire and physical injury to users. The standard includes tests 
applicable to electrical, fire or mechanical hazards, as well as 
manufacturing tests.
    UL has been unable to achieve consensus within the STP for UL 2201 
to be recognized as an ANSI standard. Therefore UL 2201, first 
published in 2009, currently exists as a UL standard without ANSI 
recognition.
    In January 2014, CPSC staff sent a letter to the UL 2201 STP Chair 
to request that a task group be formed to work on proposals to address 
the CO hazard that would eventually be balloted by the STP.\53\ The 
letter outlined a framework of requirements based on work done by and 
for CPSC staff, which could be used as a starting point for 
discussions. This letter is described in more detail in the staff's 
briefing package. Accordingly, UL formed a task group with a roster of 
37 members representing a broad range of stakeholder interests, 
including manufacturers of engines, generators, fuel-control systems 
and emission control components; public health officials; first 
responders; medical experts; indoor air quality experts; and government 
representatives from National Institute for Occupational Safety and 
Health (NIOSH), Centers for Disease Control and Prevention (CDC), NIST, 
and CPSC staff. The task group chair is a representative from NIOSH. 
The first meeting of the task group was held in May 2014. As of August 
2016, there have been 26 meetings, all held as teleconference meetings, 
and there has been active participation and constructive input from a 
number of the members, but the task group has not yet sent a proposal 
to the STP to consider for adoption into UL 2201. A more detailed 
description of this effort is provided in TAB I of the staff's briefing 
package.
---------------------------------------------------------------------------

    \53\ Buyer, Janet, letter to Diana Pappas-Jordan, RE: CPSC Staff 
Request for Formation of a Working Group and Staff's Recommendations 
for Requirements to Address the Carbon Monoxide Poisoning Hazard 
Associated with Portable Generators, January 14, 2014. http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Voluntary-Standards/Portable-Generators/CPSCstafflettertoULdatedJan142014.pdf.
---------------------------------------------------------------------------

    The Commission is unaware of any portable generator that is, or has 
been, certified to UL 2201; as such, it is unlikely that there would be 
substantial compliance with the standard it if CO emissions 
requirements were incorporated.
2. ANSI/PGMA G300-2015
    In 2011, PGMA was accredited by ANSI to be a standards development 
organization, allowing PGMA, in addition to UL, to develop a standard 
for portable generators. PGMA is the accredited standards development 
organization for ANSI PGMA G300--Safety and Performance of Portable 
Generators. CPSC staff served on PGMA's canvass committee. CPSC staff 
submitted comments to the standard, including comments regarding the 
lack of requirements in the standard to address the CO hazard.\54\ PGMA 
published the first edition PGMA G300 as an American National Standard 
in June 2015.
---------------------------------------------------------------------------

    \54\ Buyer, Janet, letter to Joseph Harding, Subj: CPSC Staff 
Comments on BSR/PGMA G300-201x, Safety and Performance of Portable 
Generators, January 2, 2015. http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Voluntary-Standards/Portable-Generators/CPSCstafflettertoPGMAregardingG300draftstandarddated122015.pdf; 
Buyer, Janet, letter to Joseph Harding, Subj: CPSC Staff Comments on 
BSR/PGMA G300-201x, Safety and Performance of Portable Generators 
dated January 30, 2015, March 6, 2015. http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Voluntary-Standards/Portable-Generators/CPSC-staff-letter-to-PGMA-with-comments-on-draft-G300-standard.pdf.
---------------------------------------------------------------------------

    PGMA G300 provides a method for testing the safety and performance 
of portable generators ``rated 15 kW or smaller; single phase; 300 V or 
lower; 60 hertz; gasoline, liquefied petroleum gas (LPG) and diesel 
engine driven portable generators intended for multiple use and 
intended to be moved, though not necessarily with wheels.'' PGMA G300 
includes construction requirements for engines, fuel systems, frame/
enclosures, alternators, and output wiring and devices. The standard 
includes safety tests intended to address electrical, fire or 
mechanical hazards during intended generator operation. It also 
includes a section on testing for determination of output power rating 
that it delineates as non-safety based. PGMA G300 also includes 
manufacturing tests to ensure minimum levels of safety for production 
units. Although the standard restates the mandatory CPSC label 
requirement for portable generators, it does not otherwise address the 
risks related to CO poisoning.
    CPSC staff continues to work with PGMA and urge them to address the 
CO hazard.\55\ CPSC staff participated in a PGMA technical summit on 
March 17, 2016, and reaffirmed this commitment.\56\ In April 2016, PGMA 
informed staff that ``the PGMA Technical Committee will create a 
performance based standard that addresses the CO hazard created when 
portable generators are misused by operating them in or near occupied 
spaces as its top priority. The performance standard, once developed, 
will be proposed to the canvass group for addition to ANSI/PGMA G300 in 
the next revision cycle.'' \57\ CPSC staff responded to PGMA \58\ and 
met with PGMA again at PGMA's request in August \59\ and September 
2016.\60\
---------------------------------------------------------------------------

    \55\ Letter from PGMA to Joel Recht, dated April 20, 2016, 
available online at: http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Voluntary-Standards/Voluntary-Standards-Reports/PGMALettertoRechtCPSCCooperationFinal.pdf.
    \56\ CPSC staff presentation, CPSC Staff Technical Research to 
Address the Carbon Monoxide Hazard for Portable Generators, March 
17, 2016.
    \57\ The Commission's understanding is that PGMA's revision 
cycle is every 5 years.
    \58\ Recht, Joel, Letter to Susan Orenga, Response to PGMA 
Letter to Joel Recht dated April 20, 2016, May 13, 2016. http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Voluntary-Standards/Portable-Generators/CPSCRechtLettertoPGMAMay132016inresponsetoPGMAletterdatedApril202016.pdf.
    \59\ Smith, Timothy, Log of Meeting, CPSC Staff, PGMA, and 
Exponent, August 12, 2016, available online at: https://www.cpsc.gov/s3fs-public/Meeting%20Log%20for%20meeting%20with%20PGMA%202016-08-12_0.pdf.
    \60\ Recht, Joel, Log of Meeting, CPSC Staff and PGMA, September 
6, 2016, available online at: https://www.cpsc.gov/s3fs-public/09%2006%2016%20Meeting%20with%20PGMA%20Follow%20up%20on%20Technical%20Summit%20on%20Carbon%20Monoxide%20Hazard%20Mitigation%20for%20Portable%20Generators.pdf.
---------------------------------------------------------------------------

    On September 19, 2016, PGMA emailed a letter to Chairman Kaye 
indicating that PGMA is in the process of re-opening G300 and 
announcing its intent to develop a ``performance strategy focused on CO 
concentrations.'' \61\ In the letter to Chairman Kaye and in CPSC 
staff's September meeting with PGMA, PGMA described only broad 
generalities of a framework for modifying G300 that involves testing a 
generator in an

[[Page 83572]]

enclosed space (test chamber).\62\ The Commission looks forward to 
working with PGMA on developing a performance requirement addressing 
the CO poisoning hazard associated with portable generators. Given that 
PGMA described only broad generalities to CPSC regarding PGMA's intent 
to modify G300, the Commission does not have an adequate basis to 
determine if modifications to the voluntary standard would likely 
eliminate or reduce the risk of injury or death. In addition, because 
the Commission is unaware of any portable generator that is or has been 
certified to G300, it is unlikely there would be substantial compliance 
if CO emissions requirements were incorporated.
---------------------------------------------------------------------------

    \61\ Letter from PGMA to Chairman Elliot Kaye, dated September 
16, 2016, available online at: https://www.cpsc.gov/s3fs-public/PGMALtrChairKayeVoluntaryStandardFinal.pdf.
    \62\ Product Safety Letter, PGMA Talks Broad Strokes on 
Standards Work with CPSC, Volume 45, Issue 34, September 12, 2016.
---------------------------------------------------------------------------

3. ISO 8528-13:2016
    ISO 8528-13:2016 Reciprocating Internal Combustion Engine Driven 
Alternating Current Generating Sets--Part 13: Safety, is a standard 
applicable to portable generators sold overseas. Its requirements 
regarding the CO poisoning hazard are limited to labels and markings. 
It requires that the generating set must have a visible, legible, and 
indelible label that instructs the user: ``exhaust gas is poisonous, do 
not operate in an unventilated area.'' The standard also requires that 
the general safety information section of the instruction manual 
mention: ``Engine exhaust gases are toxic. Do not operate in 
unventilated rooms. When installed in ventilated rooms, additional 
requirements for fire and explosion shall be observed.''

C. Adequacy of the Voluntary Standards for Portable Generators in 
Addressing CO Deaths and Injuries

    The Commission does not believe that any of the standards discussed 
in the previous section are adequate because they fail to address the 
risk of CO hazard beyond restating the CPSC mandatory labeling 
requirement and the Commission does not believe that the mandatory 
labeling requirements, alone, are sufficient to address the hazard. 
Additionally, the Commission is not aware of any firms certifying 
products to these standards. Thus, the Commission does not believe 
there is substantial compliance with the standards. Therefore, the 
Commission concludes that the voluntary standards are not adequate in 
addressing CO deaths and injuries.

VIII. Response to Comments

    In this section, we describe and respond to comments to the ANPR 
for portable generators. We present a summary of each of the 
commenter's topics, followed by the Commission's response. The 
Commission received 10 comments in response to the ANPR. Subsequently, 
in a two-part technology demonstration, CPSC contracted with UA to 
conduct a generator prototype development and durability demonstration 
program and contracted with NIST to conduct comparative testing of an 
unmodified carbureted generator and prototype generators in an attached 
garage of a test house facility. CPSC staff published a report 
regarding the results of the two-part technology demonstration program 
that included both the UA development and durability program and the 
NIST comparative testing program \63\ and received 12 comments in 
response to this report. NIST published a report concerning its 
comparative testing of generators,\64\ and staff received four comments 
in response to its report. The Commission responds to these comments, 
as well. The comments can be viewed on: www.regulations.gov, by 
searching under the docket number of the ANPR, CPSC-2006-0057.
---------------------------------------------------------------------------

    \63\ Buyer, Janet, Technology Demonstration Of A Prototype Low 
Carbon Monoxide Emission Portable Generator, September 2012. 
(available online at: http://www.cpsc.gov/PageFiles/129846/portgen.pdf and in www.regulations.gov in docket identification 
CPSC-2006-0057-0002.).
    \64\ Emmerich, S.J., A. Persily, and L. Wang, Modeling and 
Measuring the Effects of Portable Gasoline Powered Generator Exhaust 
on Indoor Carbon Monoxide Level (NIST Technical Note 1781), National 
Institute of Standards and Technology, Gaithersburg, MD, February 
2013. (available online at: http://www.cpsc.gov/Global/Research-and-Statistics/Technical-Reports/Home/Portable-Generators/PortableGenerators041213.pdf.
---------------------------------------------------------------------------

A. Mandatory Carbon Monoxide Label

    Comment: One commenter claimed that the CO hazard will continue to 
exist even if the Commission's demonstrated technology of the prototype 
were applied to commercially available generators and that ``educating 
owners about the proper use of their generators will therefore remain 
the first line of defense.'' The commenter claimed that, for this 
reason, the CPSC should ``conduct a study that includes a human factors 
analysis to determine the effectiveness of the CPSC mandated CO warning 
adopted in 2007.'' The commenter also encouraged CPSC to revise the 
mandated warning ``to incorporate the standards and format'' in ANSI 
Z535.3-2011, American National Standard Criteria for Safety Symbols, 
and Z535.4-2011, American National Standard Product Safety Signs and 
Labels.
    Response: Although the Commission concurs with the commenter that 
the CO hazard associated with portable generators will continue to 
exist to some degree, even if CPSC's demonstrated technology were 
applied to commercially available generators, it does not necessarily 
follow that educating owners about the proper use of generators is, 
should be, or would remain, the first line of defense. Human factors 
and safety literature identify a classic hierarchy of approaches to 
control hazards, based primarily on the effectiveness of each approach 
in eliminating or reducing exposure to the hazard. The use of hazard 
communications such as warning labels is universally recognized as less 
effective than designing-out the hazard of the product or guarding the 
consumer from the hazard. Thus, hazard communications are lower in this 
``hazard control hierarchy'' than these other two approaches.\65\ 
Hazard communications are less effective because they do not prevent 
consumer exposure to the hazard; instead, they must persuade consumers, 
who see and understand the communication, to alter their behavior in 
some way to avoid the hazard. Thus, hazard communications should be 
thought of as ``last resort'' measures that supplement, rather than 
replace, product redesign or guarding efforts to address residual 
risks, unless these higher level hazard-control efforts are unfeasible.
---------------------------------------------------------------------------

    \65\ Laughery, K.R., & Wogalter, M.S. (2011). The Hazard Control 
Hierarchy and its Utility in Safety Decisions about Consumer 
Products. In W. Karwowski, M.M. Soares, & N.A. Stanton (Eds.), Human 
Factors and Ergonomics in Consumer Product Design: Uses and 
Applications (pp. 33-39). Boca Raton, FL: CRC Press; Vredenburgh, 
A.G., & Zackowitz, I.B. (2005). Human Factors Issues to Be 
Considered by Product Liability Experts. In Y.I. Noy & W. Karwowski 
(Eds.), Handbook of Human Factors in Litigation (Chapter 26). Boca 
Raton, FL: CRC Press; Williams, D.J., & Noyes, J.M. (2011). Reducing 
the Risk to Consumers: Implications for Designing Safe Consumer 
Products. In W. Karwowski, M.M. Soares, & N.A. Stanton (Eds.), Human 
Factors and Ergonomics in Consumer Product Design: Uses and 
Applications (pp. 3-21). Boca Raton, FL: CRC Press.
---------------------------------------------------------------------------

    The commenter recommends that CPSC conduct a study to determine the 
effectiveness of the CPSC-mandated CO warning. The commenter states 
that testing is needed because of the importance of ``educating owners 
about the proper use of their generators.'' Based on this assertion, 
the Commission infers that the commenter's measure of effectiveness is 
the extent to which the warning is understood by consumers, assuming 
the warning had initially captured and maintained the

[[Page 83573]]

consumers' attention. CPSC's mandatory labeling requirements for 
portable generators states that the product label shall be located on a 
part of the generator that is ``prominent and conspicuous to the 
operator,'' while performing at least two of the following operations: 
Filling the fuel tank, accessing the receptacle panel, and starting the 
engine.\66\ The rule also requires that the label remain permanently 
affixed, intact, legible, and largely unfaded over the life of the 
product.\67\ These requirements, as well as the minimum type size 
requirements,\68\ were developed purposefully to address issues related 
to capturing and maintaining consumer attention and should address most 
concerns of this type, except for cases in which the user of the 
generator is not literate in English. However, the question of whether 
the label also should be provided in languages other than English was 
raised and addressed in detail in the final rule.\69\ In summary: (1) 
Available generator-related incident data have revealed no pattern of 
incidents involving people who could not read English; (2) the overall 
positive impact of adding another language to a label is likely to be 
very small; and (3) the regulation does not prohibit the addition of 
another language version of the warning message to the mandatory label.
---------------------------------------------------------------------------

    \66\ 16 CFR 1407.3(a)(iii)(B).
    \67\ 16 CFR 1407.3(a)(iv).
    \68\ The signal word ``DANGER'' must be in letters not less than 
0.15 inches and the remaining text must be in type whose uppercase 
letters are not less than 0.10 inches, or about 10-point type size.
    \69\ 72 FR 1443 (January 12, 2007).
---------------------------------------------------------------------------

    The Commission supports the testing of warnings and other hazard 
communications. However, as discussed in the preamble to the mandatory 
labeling final rule, an independent contractor already performed focus-
group testing with low-literacy individuals on the product label 
initially proposed in the notice of proposed rulemaking (NPR), and the 
Commission revised the final label to address the message text 
comprehension problems identified during testing.\70\ The Commission 
acknowledges that incremental improvements to the language of the label 
might be possible by conducting additional comprehension testing. 
However, the Commission also believes that the most significant label 
comprehension problems have already been addressed and that additional 
testing of this sort is unlikely to detect problems that would 
substantially impact comprehension among those at risk.\71\ In terms of 
the formatting of the mandatory label, the Commission notes that the 
formatting and requirements of the mandatory generator label are 
virtually identical to the requirements of ANSI Z535.4-2011 and Z535.3-
2011. Although the Commission acknowledges that the formatting of the 
mandatory label technically does not match the panel format 
requirements of ANSI Z535.4, these differences were deliberate and 
intended to improve warning comprehension. In addition, the Z535 series 
of standards includes exceptions and examples that are consistent with 
the formatting of the mandatory label. Revising the mandatory label to 
strictly meet the panel format requirements of Z535.4 is unlikely to 
improve the effectiveness of the label, and the Commission believes 
such changes actually could have a negative impact because it would 
separate the graphics from the relevant safety messages. Thus, the 
Commission believes that such revisions are neither appropriate, nor 
desirable.
---------------------------------------------------------------------------

    \70\ Id.
    \71\ Virzi, R.A. (1992). Refining the test phase of usability 
evaluation: How many subjects is enough? Human Factors, 34(4), 457-
468, has found that about 80 percent of all usability problems tend 
to be detected with only four or five subjects; about 95 percent of 
all problems are detected with nine subjects; and each additional 
subject was less likely to detect new usability problems. The 
Commission believes that these general principles are likely to 
apply to comprehension testing as well, particularly in tests that 
oversample low-literacy individuals.
---------------------------------------------------------------------------

B. Technical Requirements/Specifications

    1. Comment: Two commenters state that significant engine design 
changes would be required to incorporate and adapt emission 
technologies for use into any prototype portable generators. The 
commenters assert that engine designs that incorporate the prototype 
design changes are possible, but may not be suitable for all engines, 
especially when considering price and reliability considerations.
    Response: To reduce the CO exhaust levels in portable generator 
units, staff developed the prototype generator with commercially 
available parts for better fuel delivery controls and exhaust emission 
controls. The prototype generator did not require extensive design 
changes. The prototype generator engine was derived from a readily 
available unit with a carburetor-equipped engine, which was retrofitted 
with sensors and components for electronic microprocessor controls of 
the intake manifold fuel injection and combustion spark timing. The 
prototype engine with electronic fuel controls required no disassembly 
between the engine cover, engine block, or cylinder head. Therefore, 
the head gasket and cylinder compression rings were left in their 
original condition. Considering price, staff agrees that there is an 
added cost to EFI engines, as discussed in the preliminary regulatory 
analysis. As to reliability, staff notes that the prototype generator 
was successfully tested for its longevity in service (durability) for 
500 hours, which was the rated useful life, as established by the 
manufacturer.
    Staff notes that the CPSC prototype generator was meant to be a 
durability program demonstration to support substantially reduced CO 
emission rates and encourage research on an approach to mitigate the 
risk of fatal and severe CO poisoning. The prototype portable generator 
was not intended to be a production unit, as manufacturers would need 
to consider appropriate suitable designs for their engine families in 
portable generators. Staff's prototype findings have since been 
repeated by others who patterned their reduced CO emissions prototype 
generators on the design concept developed for CPSC by the University 
of Alabama.\72\
---------------------------------------------------------------------------

    \72\ See Techtronic Industries (TTi) presentation 3/17/16 at 
PGMA's Technical Summit on Carbon Monoxide Hazard Mitigation for 
Portable Generators--pages 85-105 of 178 page pdf file at: http://www.cpsc.gov//Global/Newsroom/FOIA/Meeting%20Logs/2016/MeetingLogPGMA31716.pdf.
---------------------------------------------------------------------------

    2. Comment: The Truck and Engine Manufacturers Association (EMA) 
asserts that similar engine designs, including basic fuel-injection and 
ignition design are uniform across several manufacturers' product lines 
of gasoline-fueled engines, where possible. Products like lawn mowers 
and portable generators may use a similar engine design and components, 
and EMA states that this uniformity across many products provides 
manufacturing flexibility and economy of scale. EMA states the 
implementation of a different engine design in portable generators, 
such as described in the prototype program, may impact cost and 
availability of the product.
    Response: The prototype design was specifically originated and 
developed through available off-the-shelf electronic fuel controller 
and components adapted onto an existing marketed portable generator 
engine. The prototype generator was successfully tested for its 
longevity in service (durability) for 500 hours, which were the 
longevity and emission outcomes of the new EFI engine through the rated 
useful life, as established by the manufacturer.
    CPSC staff acknowledges the EMA concern that adoption of a portable 
generator engine, specifically designed to reduce CO emissions, may 
have

[[Page 83574]]

different engine components pricing compared to the current portable 
generator engine without the emission reduction. CPSC staff notes that 
portable generators with EFI (though not specifically designed for low 
CO emissions) have been increasing in availability in the market as new 
models have been introduced.
    3. Comment: Honda states that the photos of the prototype unit 
cylinder head in the University of Alabama report, Prototype Low Carbon 
Monoxide Emission Portable Generator Build Description and Performance 
Evaluation,\73\ may indicate that combustion gases had been leaking to 
the outside because the head gasket was in the early stages of failure 
prior to the time that the engine was disassembled. Honda indicates 
that they made these findings based on the carbon deposits on the 
prototype cylinder head fin and head gasket seating surface, shown in 
the photos in Figure 22 of UA's report.
---------------------------------------------------------------------------

    \73\ UA's report (Puzinauskas, P, Dantuluri, R, Haskew, T, 
Smelser, J, . Prototype Low Carbon Monoxide Emission Portable 
Generator Build Description and Performance Evaluation,, The 
University of Alabama, Tuscaloosa, AL, July 2011) is available as 
TAB G in the staff report referenced previously (Buyer, Janet, 
Technology Demonstration Of A Prototype Low Carbon Monoxide Emission 
Portable Generator, September 2012.)
---------------------------------------------------------------------------

    Response: The cylinder heads, pistons and several other components 
are photographed and compared in the post durability wear analysis 
section of Contractor University of Alabama's report, Low Carbon 
Monoxide Emission Prototype Portable Generator Build Description and 
Performance Evaluation. Figure 22 in UA's report shows a side-by-side 
comparison of the cylinder heads from the baseline generator (an 
unmodified unit) to the prototype generator unit after completion of 
the 500 hours of durability testing. CPSC staff partly agrees with the 
Honda photo assessment because more carbon deposits are visible on the 
prototype cylinder head gasket surface, compared to the same component 
in the baseline. However, the prototype's head gasket endured 
approximately 585 engine hours of the durability program and subsequent 
emission testing. According to UA's report, the head gasket with the 
baseline unit leaked after 175 engine hours into the durability test 
and was replaced. The cylinder head photos, which compared the 
generator units after completion of the durability test, showing less 
carbon deposit on the baseline engine's cylinder head gasket seating 
surface may be explained by fewer accumulated engine hours on the newer 
head gasket. Furthermore, staff notes that the prototype engine had 
been run for 585 hours by the time the photograph was taken, which was 
85 hours beyond the manufacturer's rated useful life of the engine.
    4. Comment: Honda states that that the increased combustion 
temperature due to the prototype's stoichiometric air-to-fuel mixture 
and reliance on radiant cooling is insufficient, as evident in the 
condition of photographed engine components, such as the pistons, after 
completion of the durability test.
    Response: CPSC staff agrees with Honda that leaner fuel ratios 
generally result in increases in combustion temperatures. Increasing 
the air-to-fuel ratio available for combustion was intentional in the 
prototype engine, to influence and reduce the CO mass flow in the 
exhaust emission. Cylinder head temperatures were measured in generator 
units at all various load profiles for each occurrence of emission 
testing. These emission tests occurred before modifications to engine 
or durability testing, during the durability testing, in which hours of 
engine operation were accumulated, and after the durability tests.
    Emission and engine test data were collected on the as-received, 
carburetor-fueled generators units. According to the University of 
Alabama report, Low Carbon Monoxide Emission Prototype Portable 
Generator Build Description and Performance Evaluation, the as-received 
generator unit selected to become the prototype, but not yet modified, 
measured a 13.98 AFR at full generator loading (mode 1), with an 
associated 227 [deg]C cylinder head temperature. In addition, the range 
of AFR values for this pre-modified prototype generator measured 13.98-
11.26, with progressively richer AFRs toward idle or no-load. The 
maximum cylinder head temperatures with the stoichiometric EFI after 
prototype engine modification were no hotter than the original unit. 
Staff believes that the 14.0 AFR carburetor design offered no cylinder 
head cooling capacity over the stoichiometric EFI design. Throughout 
the prototype generator program, including independent laboratory 
dynamometer emission testing after 500-cyclic engine hours of 
operation, the engine demonstrated a cylinder head temperature less 
than 227 [deg]C at full load. The mid-to-no load operating temperatures 
were cooler. All of these recorded measurements of the prototype 
cylinder head temperatures, including full load, were well below the 
manufacturer-recommended temperature limits.
    Another comparison of cylinder head temperatures involves the 
baseline generator, which remained unmodified as the original unit, and 
the prototype generator. According to the Low Carbon Monoxide Emission 
Prototype Portable Generator Build Description and Performance 
Evaluation report, the carburetor fuel system of the baseline generator 
delivered 13.4 to 10.5 AFR values for the range of generator loads 
throughout the durability program. Similar to the pre-modified 
prototype generator, progressively richer AFRs occurred in the baseline 
generator towards idle or no-load. Alternatively, the prototype 
generator fuel strategy sought to maintain the same stoichiometric AFR 
across all loads. These differences in AFR values created an average 
elevated temperature of 28 [deg]C in the prototype unit to the baseline 
unit. Staff believes the 28 [deg]C average hotter temperatures across 
all loads created more discoloration in the prototype piston. There 
appears to be more blackened areas of the piston ring, and more 
coloring below the seated position of the piston ring indicate hotter 
operating temperatures in the prototype cylinder compared to the 
baseline unit. However, as mentioned, the recorded measurements of the 
prototype cylinder head temperatures, including full load, were well 
below the manufacturer recommended temperature limits. For the 
technology demonstration program, the prototype's leaner AFR to 
minimize CO exhaust production was believed to be balanced with higher, 
but acceptable, cylinder temperatures.
    5. Comment: EMA states that greater CO emission levels occurred 
with the prototype portable generator at 500 hour end-of-life compared 
to zero hour, suggesting that some deterioration of the prototype 
engine occurred with accumulation of engine hours.
    Response: The UA report contains an appendix with prototype and 
baseline generator engine-hour durability emission test results for 
low-, high- and mid-life engine hours. This appendix shows prototype 
portable generator post-catalyst CO emission results at 2 g/kW-hr near 
0 engine-hours and 17.5 g/kW-hr at 500 engine-hours. Staff does not 
believe that these results reflect deterioration, but rather, a mid-
load controller calibration performance issue, which surfaced primarily 
in the post-durability emission tests.
    This 500-hour prototype emission test performance was due to 
portions of the fuel look-up tables \74\ that were not

[[Page 83575]]

calibrated in the initiation of the engine build. Initially, it was not 
known that rated engine speeds supporting an alternator would involve 
extensive variation. Therefore, only certain areas of the controller 
look-up tables were mapped. Retrospectively, it is known that the mode 
4 or mid-load solution was simply to expand the same parameters 
throughout the ECU look-up tables and all engine speeds. In the final 
emission tests, larger AFR excursions and higher CO emissions occurred 
when the engine operated in the unmapped portions of the controller. 
While the post durability prototype generator CO emissions results show 
more than 90 percent reduction over the baseline unit, the emission 
reduction with the prototype could likely be reduced further with more 
comprehensive calibration of the controller.
---------------------------------------------------------------------------

    \74\ The fuel look-up tables are part of the electronic 
programming of the Engine Control Unit (ECU) of the EFI system. The 
tables are used to associate engine operating parameters measured by 
the system's sensors with how much fuel the injectors need to 
deliver to the combustion chamber in order for the EFI system to 
maintain the desired air/fuel mixture.
---------------------------------------------------------------------------

    6. Comment: Honda states that the CPSC testing did not evaluate 
engine and generator performance in transient load conditions of 
performance.
    Response: The empirical testing in the NIST test house included 
transient loads. NIST Technical Note 1781,i Modeling and 
Measuring the Effects of Portable Gasoline Powered Generator Exhaust on 
Indoor Carbon Monoxide Level, describes how NIST evaluated the 
performance of both the prototype and baseline unmodified generators in 
the garage, with several electrical loading variations, including the 
generator cyclic load profile in the durability program and emission 
testing.\75\ The measuring test equipment at the NIST test house 
continuously collects CO measurements as the electrical and engine load 
profile was altered. The proposed performance requirement is based on 
measuring emissions while the generator is operating with a steady load 
applied, as opposed to a transient load.
---------------------------------------------------------------------------

    \75\ Emmerich, S. J., A. Persily, and L. Wang, Modeling and 
Measuring the Effects of Portable Gasoline Powered Generator Exhaust 
on Indoor Carbon Monoxide Level (NIST Technical Note 1781), National 
Institute of Standards and Technology, Gaithersburg, MD, February 
2013 (available online at: http://www.cpsc.gov/Global/Research-and-Statistics/Technical-Reports/Home/Portable-Generators/PortableGenerators041213.pdf and in: www.regultations.gov in docket 
identification CPSC-2006-0057-0005.)
---------------------------------------------------------------------------

    7. Comment: Two commenters asserted that CPSC's prototype 
components may cause exacerbated reliability issues after long-term 
storage.
    Response: Staff disagrees because fuel-injection improves 
reliability. A fuel-injected system is sealed, so the fuel is not 
exposed to air like the vented system associated with a carburetor. 
Exposure to air significantly contributes to degrading gasoline during 
long-term storage and, in turn, causes problems with starting and 
running the engine. Manufacturers advertise improved reliability as one 
of the benefits associated with fuel injection.
    Comment: One commenter asserted that it is harder to apply EFI and 
catalyst on the smaller engines used in 1 kW-3 kW units and that they 
are sold in higher numbers than 5 kW units. In a similar comment, 
another commenter noted that CPSC's prototype used a commercial-grade 
engine in open frame, yet closed-frame units are more popular.
    Response: CPSC has observed that there are fuel-injected handheld 
Class I engines, with and without catalysts, in the marketplace. CPSC 
acknowledges, however, that there may be more challenges associated 
with implementing the emission control technology on these smaller 
engines and the generators that these engines power. Thus, there is a 
later compliance date in the proposed rule for these models, relative 
to the larger generators powered by Class II engines. Based on CPSC 
staff's analysis of the market data, CPSC concurs that smaller 
generators are becoming more popular, relative to larger generators. 
CPSC staff used a larger generator, powered by a class II, single-
cylinder engine, in the technology demonstration program because the 
Commission's incident data show that generators with these engines were 
associated with almost two-thirds of the CO deaths involving generators 
that have been reported to CPSC, when the size of the generator was 
identified, for the years from 2004 through 2012. The lower proposed 
performance requirements for smaller generators are expected to reduce 
deaths that could otherwise be expected to occur with increasing 
popularity of these smaller units.
    8. Comment: One commenter stated that stable engine operation under 
transient loads requires richer-than-stoichiometric AFR. Without it, 
the commenter asserted, there is unreliable operation, which can result 
in damaged electrical loads and warranty claims.
    Response: The Commission acknowledges this operating challenge, and 
for this reason, the proposed performance requirement is based on 
measuring emissions while the generator is operating with a steady load 
applied, as opposed to a transient load.
    9. Comment: One commenter noted that their company uses more severe 
modes and requirements to test product durability, which they are 
doubtful the prototype would have survived. In a related comment, a 
commenter asserted that significantly reduced CO emissions at the 
highest loads resulting from operation near stoichiometric fuel control 
will negatively impact engine durability.
    Response: The Commission notes that the proposed performance 
requirement for generators powered by class II single-cylinder engines 
is nominally six times higher (less stringent) than the CO rate that 
the prototype generator achieved. The Commission believes that the 
proposed CO emission requirements can be achieved on many existing 
engines by replacing the carburetor with closed-loop EFI and 
integrating a catalyst without engine design modification and without 
negatively impacting engine durability. The Commission notes, however, 
that for some engines, modifications might be needed to enable 
operation closer to stoichiometry. For other engines that cannot be 
improved through design modifications, those could still be used in 
generator applications by using a product integration strategy that 
precludes installed engine operation at loads where fuel enrichment is 
needed.
    10. Comment: One commenter stated that the performance standard for 
CO emission rates must take into account deterioration of emissions to 
achieve the target exposure over the life of the engine.
    Response: The Commission took deterioration into account in 
developing the performance requirements. The Commission believes 
deterioration of CO emissions to be minimal. This is based on both the 
performance of CPSC's durability-tested prototype at end of life as 
measured by CES, as well as by observation of published deterioration 
factors for CO, which are measures of the increase in CO emissions for 
an aged engine, relative to its emissions when new. The Commission 
observed in the EPA's exhaust emission database for model year 2015 
that a vast majority of the engines have a deterioration factor below 
1.1 (thus indicating the emissions worsen by less than 10 percent above 
initial emissions).
    11. Comment: One commenter stated that the target CO emission rate 
in terms of g/kW-hr should be based on engine displacement, with lower 
rates (in terms of g/kW-hr) for larger engines to achieve the same 
target exposure.
    Response: The Commission believes lower CO emission rates are 
technically feasible for smaller engines, compared to larger engines. 
Consequently, the Commission is proposing performance requirements for 
four different size

[[Page 83576]]

categories of generators that are each based on technical feasibility 
and analysis of benefits and costs as a function of engine 
displacement, and, for the largest category, also whether the engine 
has one or two cylinders. The epidemiological benefits considered 
exposure differences for different generator types, by allocating known 
incidents based on location of generator and location of victims in 
various house types.
    12. Comment: One commenter asserted that reducing CO emissions will 
increase other pollutant emissions and risk of fire and burn hazard.
    Response: The Commission does not agree that reducing CO emissions 
will increase other pollutant emissions. Based on the emission results 
from CPSC's prototype generator, as well as those from the EPA's 
demonstration program, reducing CO emission rates also results in 
reduced HC+NOX emissions. CPSC staff acknowledges that for 
CPSC's prototype, the leaner air fuel ratio resulted in elevated 
exhaust temperatures compared to the carbureted configuration. Staff 
notes, however, that the muffler that was used was chosen to easily 
accommodate integration of the small catalyst into it. This muffler had 
less internal baffling, which resulted in average muffler surface 
temperatures of approximately 70[deg]C hotter than the OEM design. As a 
result, UA shrouded this muffler and that resulted in shroud surface 
temperatures that were lower than the OEM muffler that was not 
shrouded. Staff notes that use of better designed mufflers, and, if 
needed, improved flow of cooling air over the exhaust, could mitigate 
the effect of elevated exhaust temperatures.
    13. Comment: One commenter stated that EFI systems are becoming 
more low cost and noted that an oxygen sensor of one particular design 
can serve as a safety switch if the engine starts operating rich of 
stoichiometric.
    Response: The Commission has observed that small SI engines with 
EFI have entered the marketplace in recent years, and expects this 
would mean that they have become less expensive. The Commission is 
interested in combining reduced CO emissions with a mechanism that will 
shut off a generator when operated in an enclosed or semi-enclosed 
space.
    14. Comment: One commenter stated that the results from testing the 
generators in NIST's garage should not be relied upon for any 
rulemaking related to portable generator safety because, the commenter 
asserted, the attached garage on NIST's test house is not sufficiently 
representative of how garages are conventionally constructed.
    Response: The Commission used the results from NIST's test house to 
provide an example of the reduction in the house's hypothetical 
occupants' exposure that the reduced CO emission rate from a portable 
generator can yield when compared to a current carbureted generator 
when operated in the same garage. The Commission is basing the proposed 
performance requirements for the rule on technically feasible CO 
emission rates, along with an assessment of the impact of those rates 
through indoor air quality modeling of 40 structures, representative of 
the U.S. housing stock, where generators were operated in 503 of the 
deaths in CPSC's databases that occurred from 2004 through 2012.
    15. Comment: Several commenters expressed concern about CO deaths 
caused by generators and expressed support for reducing generators' CO 
emission rates and their belief in the technical feasibility to do so.
    Response: The Commission agrees with the commenters.

C. CO Poisoning Effects

    1. Comment: The commenter considers that CPSC staff assumes COHb 
levels below 10 percent are not harmful. The commenter notes that there 
is no scientific basis for such an assumption and also notes that, in 
many studies, COHb levels do not correlate consistently with symptoms.
    Response: The Commission does not assume that a CO exposure 
resulting in less than 10 percent COHb is incapable of causing adverse 
health effects. The Commission has long recognized the existence of 
populations especially sensitive to CO health effects (fetuses, 
asthmatics, and individuals with cardiovascular diseases). Most 
authorities, including CPSC, consider individuals with coronary artery 
disease [CAD] to be the population most sensitive to potential adverse 
health effects of CO at the lowest exposure levels. Some studies report 
individuals with CAD might perceive adverse health effects, and/or, 
tests show that they may experience adverse health effects that they 
are unaware of, at about 2 percent to 5 percent COHb. The Commission 
understands that the pathophysiological effects of CO are complex and 
strongly influenced by multiple factors, particularly CO level, 
exposure duration, and exposed individual's inhalation rate and health 
status. In the ANPR on portable generators, and in the prototype report 
documents, CPSC focused on extremely high-level, acutely lethal, CO 
exposures caused by generator exhaust. Therefore, rather than provide 
an exhaustive review of all studies, including equivocal findings in 
some low-level exposure studies, CPSC is providing an overview of the 
complex interactions between multiple variables that influence the end 
effects of acute, high-severity CO exposures in humans. CPSC emphasizes 
that CO poisoning effects should be understood to be a continuum of 
effects of the exposure, rather than be viewed as discrete health 
effects tightly tied to specific CO levels or COHb levels.
    2. Comment: One commenter stated that although a low CO emissions 
generator would undoubtedly save lives if widely applied, ``prediction 
of confusion and incapacitation from COHb levels is not possible.'' The 
commenter cited his recent publication reporting that ``symptoms of CO 
poisoning do not correlate well with COHb levels.'' Based on his 
findings and other clinical reports, the commenter questions the 
validity and/or concept of a table relating COHb levels to particular 
symptoms, as used by the Commission. The commenter believes that it is 
incorrect to use COHb levels to calculate egress times from a CO-
containing environment and notes that there are no data to support the 
method. Another commenter also questioned the validity of an 
approximate relationship between COHb levels and severity of CO 
poisoning symptoms and health effects.
    Response: The Commission's use of predicted COHb levels was not 
intended to calculate an actual egress time from a CO exposure, and the 
Commission noted that reduced emission generators would not guarantee 
egress by exposed individuals. Rather, the Commission considers that 
reduced generator CO emissions, as achieved with its prototype unit, 
will substantially delay the rate at which CO levels rise in poorly 
ventilated spaces, and will thus delay the rate at which COHb levels of 
exposed individuals rise (in some cases reducing the peak COHb level 
attained). This will provide significantly increased time available for 
individuals to remove themselves from the exposure environment or to be 
rescued by an outside party. Supporting evidence that some individuals 
will react appropriately to slower onset of CO poisoning effects has 
been reported (e.g., 111 of 167 patients with CO poisoning presented to 
Florida hospital emergency departments (ED) between 5 a.m. and 10 a.m., 
after waking and feeling ill consequent to overnight use of a generator 
during hurricane-related power outages). CPSC data indicate that in 69 
of 93 cases where it was known

[[Page 83577]]

how and why a patient with generator-related CO exposure presented to 
an ED, the patient had either transported themselves or contacted 
others (9-1-1, family, friends) to arrange for their transport to the 
ED. In the remaining cases, individuals were found in distress by 
others (either a lesser affected co-exposed individual or an outside 
party).
    The Commission recognizes that even healthy individuals can exhibit 
variability in individual susceptibility to CO health effects under 
identical exposure scenarios. The Commission understands that, in 
clinical situations, CO poisoning symptoms and health effects do not 
necessarily correlate well with a patient's initial COHb measurement, 
which is often confounded (generally reduced by factors such as time 
interval relative to cessation of CO exposure and provision of 
supplemental oxygen). Clearly, COHb measurements can be of limited 
value to physicians when determining appropriate treatment plans for 
individual patients. Rather than make clinical decisions, the 
Commission needed to provide controlled, systematic comparisons of how 
CPSC's reduced CO emissions prototype generator could be expected to 
reduce the lethal CO hazard presented by the unmodified original 
generator. Therefore, CPSC used identical physiological input 
parameters for a healthy adult to model COHb formation and elimination 
from empirical generator CO time course exposure data. CPSC used 
predicted times taken to rise to, and progress through, three 
convenience benchmark percentile COHb values to compare the relative CO 
poisoning hazard presented by a generator before and after design 
modifications to reduce its CO emission rate. The Commission considered 
these benchmark values to approximate relatively mild (20% COHb), 
potentially incapacitating (40% COHb), and likely lethal (60% COHb) 
exposure levels. Although indicating health effects generally first 
reported at these benchmark COHb levels, CPSC did not intend to convey 
that they represented precise measures when appearance of symptoms and 
adverse health effects would be expected in all individuals. CPSC noted 
that rapidly rising, high-level CO exposures of several thousand ppm 
(as can occur with current carbureted generators) would result in 
extreme oxygen deprivation and fast-rising COHb levels, causing rapid 
incapacitation, loss of consciousness and death, without individuals 
necessarily experiencing milder, progressively worsening CO poisoning 
symptoms typically manifested in slowly rising or lower-level CO 
exposures.
    As further detailed in the staff's briefing package, the available 
physiological research data and clinical findings in the scientific 
literature support the use of ``COHb benchmarks,'' for approximate 
estimation and comparison of CO-related health effects expected during 
generator-related exposures.\76\ The Commission welcomes suggestions on 
alternative health-based approaches to compare the reduced CO emissions 
generators with current products in terms of improved safety benefits.
---------------------------------------------------------------------------

    \76\ Tab K, Appendices, of staff's briefing package.
---------------------------------------------------------------------------

D. Jurisdiction

    Comment: One commenter asserted that pursuant to Sec.  31 of the 
CPSA, the CPSC lacks authority to regulate the risk of injury 
associated with CO emissions from portable generators because that risk 
could be addressed under the Clean Air Act (CAA). Specifically, the 
commenters rely on Section 213 of the CAA, which directs the EPA to 
conduct a study of emissions from non-road engines to determine if they 
cause or contribute to air pollution, ``which may reasonably be 
anticipated to endanger public health or welfare.'' 42 U.S.C. 
7547(a)(1)(2006). Under this provision of the CAA, the EPA has 
promulgated regulations governing CO emissions from portable 
generators. In particular, 40 CFR part 90 imposes requirements to 
control emissions from non-road spark-ignition engines, which includes 
portable generators, at or below 19 kilowatts.
    Response: Section 31 of the CPSA does not establish an absolute 
prohibition to CPSC action whenever the CAA is implicated. Rather, the 
Commission lacks authority to regulate a risk of injury associated with 
a consumer product if that risk ``could be eliminated or reduced to a 
sufficient extent through actions'' taken under the CAA. 15 U.S.C. 
2080(a). Case law and the legislative history of Sec.  31 confirm this. 
See ASG Industries, Inc. v. Consumer Product Safety Comm'n, 593 F.2d 
1323 (D.C. Cir. 1979) (under section 31, CPSC is to consider all 
aspects of the risk and make a judgment whether the alternate statute 
can sufficiently reduce the risk of injury).
    The legislative history indicates that Congress contemplated a 
stricter ban on the CPSC's jurisdiction and rejected it. Specifically, 
the Senate version of the bill for Sec.  31 would have precluded CPSC's 
jurisdiction if the product was ``subject to safety regulations'' under 
one of the statutes listed in section 31 of the CPSA. S. Rep. No. 92-
749, 92d Cong., 2d Sess. 12-13 (1972). In contrast, as the ASG court 
noted, under the House version of the bill, which was eventually 
enacted, the Commission has authority if there has not been sufficient 
reduction or elimination of the risk of injury. H.R. Rep. No. 92-1593, 
92d Cong., 2d Sess. 38 (1972).
    The CAA and the EPA regulations promulgated under it that address 
CO emissions from portable generators have not sufficiently reduced or 
eliminated the risk of CO poisoning associated with portable generators 
that the CPSC seeks to address. Deaths and injuries associated with CO 
emissions from portable generators have increased since the EPA adopted 
its regulations limiting CO emissions from the type of engines used in 
portable generators.
    The CAA and the EPA's regulations create national standards 
intended to address large-scale ambient air pollution, not acute CO 
exposure from portable generators. The CAA and the EPA's regulations, 
created under 42 U.S.C. 7407, are designed to reduce CO emissions in 
regional areas that exceed National Ambient Air Quality Standards. 
These requirements are not designed to reduce the localized risk to 
consumers from acute CO poisoning when portable generators are used in 
the home.
    Additionally, EPA's 2008 adoption of an averaging program for CO 
emissions from marine engines further demonstrates that its regulations 
are not concerned with the risk of acute CO poisoning, but only large-
scale overall emission levels. This averaging program allows a 
manufacturer to exceed the EPA's CO emission limits for a group of 
similar engines, as long as the manufacturer offsets that increase with 
another ``engine family'' with emission levels below the EPA's limit. 
73 FR 59,034 (Oct. 8, 2008). It is noteworthy that this averaging 
program applies to CO emissions from marine engines, which the EPA 
explicitly acknowledges are associated with ``a substantial number of 
CO poisonings and deaths.'' 73 FR 59,034, 59,048 (Oct. 8, 2008). Under 
this program, emissions from an individual engine are inconsequential 
to EPA's rule, and so is the individual consumer's exposure level. 
Rather, the EPA's determination of CO emission limits focuses on 
ambient air pollution on a large scale.
    Finally, the structure of the CAA and its delegations of authority 
make the EPA unable to adequately address the risk of injury associated 
with CO poisoning to consumers from portable

[[Page 83578]]

generators. Under the CAA, the EPA sets National Ambient Air Quality 
Standards (NAAQS) and has oversight and enforcement authority, but the 
states retain primary responsibility for ensuring air quality. Section 
107 of the CAA sets out states' responsibilities for ensuring air 
quality, including determining how the state will meet NAAQS, and 
identifying attainment and non-attainment areas. 42 U.S.C. 7407. The 
U.S. Supreme Court has emphasized that the EPA is ``relegated by the 
[CAA] to a secondary role,'' as long as states adopt plans that meet 
the general requirements. Train v. Natural Resources Defense Council, 
Inc., 421 U.S. 60 (1975). This broad leeway provided to states 
indicates that the CAA and the EPA's regulations are not intended to 
and cannot provide sufficient specificity to mitigate the risk of CO 
poisoning.

E. CO Sensor Systems and Exhaust Pipe Extension

1. Generator-Mounted CO Sensing Shutoff Systems
    Comment: Four comments were submitted on the concept of a 
generator-mounted safety shutoff system using CO sensing technologies 
that could be used to limit consumer exposure to CO present in portable 
generator exhaust. Three of the four commenters advocated for such a 
system, and one advocated against it.
    One comment in support of the use of residential CO alarm 
technology noted that a CO sensor that is used to activate ventilation 
systems in parking garages can be used for turning off the generator 
when it senses 35 ppm CO. The Commenter also recommended that the 
system be interlocked to prevent generator operation every 2 to 3 
years, when the sensor's useful life is expended, and to prevent 
operation, if the user disables the system.
    The commenter who did not recommend the use of residential CO alarm 
technology expressed the belief that COS sensing technology near a 
generator may impair its operation, causing users to disconnect the 
sensors to ensure a steady source of electricity. The Commenter also 
noted that CO sensors require routine maintenance, and their 
capabilities can degrade with time and during extended periods of 
inactivity, adding that it may be unreasonable to expect consumers to 
regularly check and maintain the CO sensing equipment, particularly 
when the generator is not even being used.
    Response: The Commission shares the concern that using CO sensing 
technology in the vicinity of a portable generator may impair the 
generator's operation, causing users to disconnect the sensors. The 
Commission agrees that it is unreasonable to expect consumers to 
regularly check and maintain CO sensing equipment, particularly when a 
generator is not being used. Early in the portable generator project, 
the Commission investigated one version of the concept of an on-board 
CO sensing shutoff system; the investigation and its findings are 
documented in the staff report, Phase 2 Test Report: Portable Generator 
Equipped with a Safety Shutoff Device (Brown, 2013). Its goals were to: 
(1) Determine if a CO sensor/alarm output signal from commercially 
available residential CO alarms (meeting the requirements in UL 2034 
Single and Multiple Carbon Monoxide Alarms), when retrofitted with 
circuitry connected to the generator, could trigger a shutoff device 
installed on a portable generator when the CO alarm activated; and (2) 
measure CO concentrations around the generator when operated in 
multiple environments to assess CO migration and levels that might 
occur under several scenarios. Test environments examined included 
outdoors, in a two-sided structure, as well as inside and under a 
temporary modular storage (TMS) building.
    In that investigation, the Commission found that when the generator 
was operated inside the TMS building, the CO migrated and accumulated 
on the far side of the room more quickly than near the generator. The 
CO alarms on the generator never activated before those located 
elsewhere in the space activated, with the time difference generally 
ranging from 5 to 10 minutes. In some tests, CO levels in some parts of 
the room reached up to 1,000 ppm before the CO alarm on the generator 
activated and shut off the generator. When the generator was operated 
in wide-open outdoors in a light breeze condition, CO concentrations 
ranging up to 350 ppm were measured in the immediate vicinity of the 
generator. Although this did not activate the CO alarms mounted on the 
generator to shut it off, the Commission believes this could occur in 
some circumstances. This would detrimentally affect the utility of the 
generator when used in a proper location.
    In addition to these performance deficiencies, the Commission is 
concerned about the ability of CO sensors to survive the environments 
produced by an operating generator. Currently available electrochemical 
and semiconductor CO sensors, which dominate the CO sensing market, 
have numerous vulnerabilities that will compromise their ability to 
maintain accuracy if they are used in an atmosphere containing high 
concentrations of hydrocarbons, as is present in a generator's exhaust, 
particularly when used in a confined space.
    Regarding one commenter's recommendation to use CO sensors that 
turn on ventilation fans in parking garages, a recent energy efficiency 
study examining the performance of parking garages that have CO-sensing 
activated ventilation indicates that this type of system is subject to 
failure if not maintained on the manufacturer's recommended schedule 
(California Utilities Statewide Codes and Standards Team, 2011). 
Systems employing both electrochemical and solid state technology that 
were five and 12 years old, respectively, failed likely because they 
had not been calibrated. A properly maintained 2-year-old 
electrochemical sensor-equipped system performed well. The commenter 
suggested that to account for the referenced 2 to 3 year expected 
sensor life, the consumer replace the sensor at the end of the sensor's 
useful life. The Commission believes that it is not appropriate for 
consumers to be required to replace a primary safety device, let alone 
replace it every 2 to 3 years, when the life of the overall product is 
much longer. Furthermore, making the sensor replaceable makes it 
vulnerable to tampering. Notwithstanding the previously mentioned CO 
concentrations that CPSC measured around a generator operating in a 
proper location, the conflict between making the sensor consumer-
replaceable and tamper-proof leads the Commission to conclude that 
currently available sensors are not likely to be effective, given the 
long service life of portable generators. With respect to the 
recommendation for a 35 ppm CO set point for an on-board sensor, CPSC 
measured CO concentrations in excess of 35 ppm in the immediate 
vicinity of the generator, while operating outdoors within 11 minutes 
after starting the generator (Fig C2 in Brown, 2013). A 35 ppm limit 
for shutoff would greatly limit the utility of portable generators when 
used properly.
2. Remotely Located CO-Sensing Shutoff Systems
    Comment: Two commenters raised concerns about the concept of a 
remotely located CO-sensing shutoff system, such as that investigated 
and documented in the staff report, ``Demonstration of a Remote Carbon 
Monoxide Sensing Automatic Shut-Off Device for Portable Generators'' 
(Lee, 2006). Conceptually, a remotely located

[[Page 83579]]

CO-sensing shutoff system would use a CO sensor located indoors to 
monitor for CO infiltration at that location and when it detects an 
unsafe CO concentration there, the sensing shut-off device would 
communicate with the generator to shut it off. The report presents CPSC 
staff's investigation of one version of such a concept, consisting of a 
CO alarm retrofitted with a wireless transmitter, placed by the user in 
an indoor location, which communicated with a wireless receiver mounted 
onto a portable generator operating in an attached garage. When the CO 
alarm activated, it energized a circuit on the generator and shut off 
the generator.
    One commenter raised a number of behavioral and technical issues on 
the utility of such a system. This commenter noted that the same 
technical comments he made on the generator-mounted safety shutoff 
concept, discussed above, apply to the remote-sensing concept as well. 
This commenter also noted that remote-sensing technologies require 
consumers to take affirmative actions to properly locate sensors inside 
buildings and to monitor them to make sure that they continue to be 
operational. The commenter stated that the risk of the CO poisoning 
hazard would not be mitigated when consumers fail to locate or use the 
sensing technology properly or the detector malfunctions due to 
infrequent use or lack of maintenance.
    Another commenter enumerated a number of concerns about the concept 
of a remote CO-shutoff system that included:

 Sensor performance affected by ambient conditions
 battery life
 the ability of consumers to install
 nuisance trips causing consumers to disable system
 the need to maintain proper battery charge
 ability of consumer to start generator, then remove the remote 
sensor to an area without CO, to allow the generator to operate.

    Regarding the staff report, the commenter objected that only one 
model generator was included in the tests and that only a limited 
number of hazard scenarios were tested. The commenter provided a list 
of options that would need to be investigated to document remote CO-
sensing device acceptability. The options include: (1) Effectiveness of 
the mandatory warning label; (2) effects of environmental conditions on 
CO dispersion in a building; (3) effect of generator load profile on CO 
dispersion; (4) effect of walls and building materials on the sensor's 
radio frequency (RF) signal to the generator; and (5) maximum distance 
between sensor/transmitter and the generator. Additional areas the 
commenter listed include: (6) Consumer's ability to reset the system in 
adverse conditions (darkness, storms); (7) timing of product sales 
(pre- or post-storm); (8) minimum component performance requirements; 
and (9) minimum battery requirements.
    Response: The Commission agrees that there are multiple challenges 
with a remote CO-shutoff concept for portable generators, including 
many of the challenges identified by the commenters and notes that the 
staff report concluded with the following:
    The study was limited to proof-of-concept and did not consider 
issues such as life expectancy, reliability, usability, and 
environmental conditions. All of these factors would need to be 
considered in developing a remote CO detection/shut-off system for 
portable generators for consumer use.
    In addition to having the same sensor-related concerns as those 
stated above in CPSC's response to the on-board CO sensing shutoff 
concept, CPSC has additional concerns, a primary one being that a 
system of this sort would need to be provided with the generator and 
would require the consumer to properly install the sensing devices. The 
consumer could easily defeat the features by operating the generator in 
an enclosed location and intentionally placing the sensor outdoors or 
other locations away from where the CO is infiltrating in order to keep 
the generator running. Another scenario of concern involves the user 
placing the CO sensor in a room where he/she thinks the CO will 
infiltrate, but the CO infiltrates faster in another room that the 
system is not monitoring. Transmitter range is another concern; if a 
consumer properly locates the generator outdoors at a distance far 
enough from the dwelling to prevent CO infiltration, the distance may 
render the generator inoperable if it is not within range of the sensor 
signal. Based on the concerns mentioned above, the Commission is not 
pursuing this concept as a means of reducing the CO hazard associated 
with portable generators.
3. Flexible Exhaust Pipe Extension
    Comment: One commenter recommended using an exhaust hose that has 
one end that fits over the tailpipe and a laterally expandable window 
fitting on the other end to direct exhaust out through a window. The 
commenter recommended that the hose should have an electrical circuit 
wired through its entire length, which plugs into the generator to 
prevent operation if the hose is not properly attached.
    Response: There are several drawbacks to this approach. First, if 
the hose must be attached for the generator to operate, then it must be 
attached even if the generator is correctly located away from the 
house. CPSC believes this is not practical. Second, the CPSC database 
includes fatal CO incidents where the generator was located outside the 
dwelling, but not so far away to prevent exhaust from entering the home 
through leaks or openings (Hnatov, 2015). Third, CPSC staff believes 
that it is unlikely that an expandable window insert can be installed 
in such a way as to be leak tight. Last, this system's successful use 
depends on the consumer's ability to properly install both the hose and 
the window fitting. Given these concerns, the hose extension is not a 
technically feasible approach to address the carbon monoxide poisoning 
hazard associated with engine-driven portable generators.

F. Economic Considerations

    On February 12, 2007, counsel for American Honda Motor Co., Inc., 
Briggs & Stratton Company, and Yamaha Motor Corporation, USA (the 
companies), submitted comments jointly on the December 12, 2006 advance 
notice of proposed rulemaking (ANPR), concerning portable generators. 
The companies made the following comments on economic issues:
    1. Comment: The vast majority of consumers use their portable 
generators properly and safely. CPSC should give proper weight to the 
benefits and widespread uses of portable generators, as well as the 
affordability of current models.
    Response: Although the great majority of consumers might exercise 
proper safety precautions, improper use of the product can and does 
have disastrous consequences. The Commission evaluated different 
technologies to address the risk and has concluded that a performance 
standard that sets requirements that reduce CO emissions from 
generators is the most reliable regulatory alternative to address the 
risks of CO poisoning associated with portable generators. 
Manufacturing cost increases under the proposed rule would generally 
have a relatively greater impact on percentage price increases (and 
consumer demand) for low-price units, such as units lacking inverter 
technology (as discussed in the preliminary regulatory analysis 
section). However, the analysis finds that the

[[Page 83580]]

estimated benefits outweigh the costs to comply with the proposed rule.
    2. Comment: Staff has not provided consumer exposure data to 
support risk analysis of CO deaths associated with consumer use of 
generators.
    Response: Since the comment was filed, additional information and 
analysis has greatly improved the analysis of risks associated with 
consumer use of portable generators. The Commission's preliminary 
regulatory analysis has analyzed historical shipment information 
acquired from market research firms (Power Systems Research and 
Synovate), from federal data sources (the International Trade 
Commission and Bureau of the Census), and from individual manufacturers 
to estimate the numbers of portable generators in use, by engine class 
and other characteristics, during the period covered by CPSC staff's 
epidemiological benefits analysis (Hnatov, Inkster & Buyer, 2016). The 
new information and analysis has enabled CPSC to estimate CO poisoning 
risks (and societal costs) per generator in use. Additional information 
on product sales and use, which the industry is encouraged to provide 
in comments to this NPR, could further refine these estimates.
    3. Comment: In response to the technology demonstration report, one 
commenter stated that although engine designs that incorporate the 
report's design changes \77\ are possible, they may not be suitable for 
all engines, including many used to power portable generators. This is 
especially true when considering the price point and reliability 
considerations associated with portable generators designed and sold to 
consumers for emergency or infrequent use.
---------------------------------------------------------------------------

    \77\ Mr. Gault is referring to the incorporation of an 
electronic control unit, manifold air pressure sensor, fuel pump, 
fuel injector . . . exhaust oxygen sensor, catalyst aftertreatment 
and other components used on the prototype generator.
---------------------------------------------------------------------------

    Response: As noted, we agree that some types of generators (and 
engines) will be more severely affected by a proposed rule that is 
performance based, but is likely to be addressed by manufacturers 
through the use of EFI and catalysts (although some generators with 
handheld engines might not require catalysts) in terms of relative 
price increases that would result from incorporation of the 
technologies. The impact on demand for these products could affect 
their future availability to consumers.

IX. Description of the Proposed Rule

A. Scope, Purpose, and Compliance Dates--Sec.  1241.1

    The proposed standard would apply to ``portable generators'' 
powered by small handheld and non-handheld SI engines, and would 
include requirements intended to limit carbon monoxide emission rates 
from these portable generators. The requirements are intended to reduce 
an unreasonable risk of injury associated with portable generators.
    Generators within the scope of the proposed rule provide receptacle 
outlets for AC output circuits and are intended to be moved, although 
not necessarily with wheels. Products that would not be covered by the 
proposed rule include permanently installed stationary generators, 50 
hertz generators, marine generators, generators installed in 
recreational vehicles, generators intended to be pulled by vehicles, 
generators intended to be mounted in truck beds, and generators that 
are part of welding machines.\78\ Generators powered by compression-
ignition (CI) engines fueled by diesel also are excluded from the scope 
of the proposed rule.\79\
---------------------------------------------------------------------------

    \78\ Stationary generators, marine generators, and generators 
installed in recreational vehicles are excluded because they are not 
portable. Generators intended to be pulled by vehicles, intended to 
be mounted in truck beds, generators that are part of welding 
machines, and 50-hertz generators are excluded because they are not 
typically used by consumers.
    \79\ CI engines are not typically used by consumers. In 
addition, CI engines have relatively low CO emission rates. The 
current EPA standard for CO emissions from CI engines rated below 8 
kW is 8.0 g.kW-hr, which is significantly lower than the EPA 
standard of 610 g/kW-hr applicable to small SI engine classes used 
in portable generators.
---------------------------------------------------------------------------

    The requirements would apply to four categories of portable 
generators: (1) Handheld generators; (2) class 1 generators; (3) class 
2 single-cylinder generators; and (4) class 2 twin-cylinder generators. 
Handheld engines have total engine displacement of 80 cubic centimeters 
(cc) or less; non-handheld engines include EPA Class I engines, which 
have total engine displacement of less than 225cc, and Class II 
engines, which have displacement of 225cc and more. Class II engines 
have an upper limit determined by rated engine power, 19 kilowatts 
(kW), which is equivalent to 25 horsepower. Although the Commission 
categorized generators by the EPA classification of the engines 
powering them, it is important to distinguish these engines from the 
portable generators in which they are used because the engines are used 
in other products as well. To provide a clear distinction, the 
Commission refers to engines according to EPA's classification: 
Handheld engines, non-handheld Class I engines and non-handheld Class 
II engines, while referring to portable generators according to the 
Commission's definitions, handheld generators, class 1 generators, 
class 2 single-cylinder generators and class 2 twin-cylinder 
generators.
    Under the CPSA, the effective date for a consumer product safety 
standard must not exceed 180 days from the date the final rule is 
published, unless the Commission finds, for good cause, that a later 
effective date is in the public interest. To meet the proposed 
performance requirements, it is likely that engines will need closed-
loop fuel-injection, and with the exception of some handheld engines, 
the addition of a catalyst. Implementing closed-loop EFI and catalyst 
integration on all class II (single- and twin-cylinder) engines 
powering generators may require design modifications, such as redesign 
of cooling fins and a fan, to accommodate fuel control closer to 
stoichiometry. The Commission believes 180 days may not be adequate 
time to allow for such design modifications, and is instead proposing 
an effective date of 1 year following publication of the final rule, at 
which time portable generators with Class II single- and twin-cylinder 
engines, or class 2 single- and twin-cylinder portable generators, 
would be required to comply with the applicable requirements of the 
rule. The Commission proposes a compliance date of 3 years after 
publication of the final rule for generators powered by Class I engines 
and handheld generators, or class 1 and handheld generators. This later 
compliance date is to address manufacturers' concerns that, while 
industry has gained some limited experience with incorporating fuel 
injection on handheld and Class I engines, there may be different 
challenges associated with accommodating the necessary emission control 
technologies on these smaller engines. In addition, later compliance 
dates potentially could reduce the impact on manufacturers of 
generators, including small manufacturers, by providing them with more 
time to develop engines that would meet the requirements of the 
proposed rule, or, in the case of small manufacturers that do not 
manufacture the engines used in their generators, by providing them 
with additional time to find a supplier for compliant engines so that 
their generator production would not be interrupted.

[[Page 83581]]

B. Definitions--Sec.  1241.2

    The proposed standard would provide that the definitions in section 
3 of the Consumer Product Safety Act (15 U.S.C. 2051) apply. In 
addition, the proposed standard would include the following 
definitions:
    (a) handheld generator means a generator powered by a spark-ignited 
(SI) engine with displacement of 80 cc or less.
    (b) class 1 generator means a generator powered by an SI engine 
with displacement greater than 80 cc but less than 225 cc.
    (c) class 2 single-cylinder generator means a generator powered by 
an SI engine with one cylinder having displacement of 225 cc or 
greater, up to a maximum engine power of 25 kW.
    (d) class 2 two-cylinder generator means a generator powered by an 
SI engine with two cylinders having a total displacement of 225 cc or 
greater, up to a maximum engine power of 25 kW.

C. Requirements--Sec.  1241.3

1. Description of Requirements
    The proposed rule would require that portable generators powered by 
handheld engines and Class I engines, or handheld and class 1 
generators, not exceed a weighted CO at a weighted rate more than 75 
grams per hour (g/h); generators powered by one-cylinder Class II 
engines, or class 2 generators, must not exceed a weighted CO emission 
rate of 150 g/h; and generators powered by Class II engines with two 
cylinders, or class 2 twin-cylinder generators, not exceed a weighted 
CO emission rate of 300 g/h. The weighted emission rates are based on 
weighting of six modes of generator operation, ranging from maximum 
generator load capability (mode 1) to no load (mode 6), similar to a 
procedure used by EPA to certify compliance with its emission standards 
for small SI engines.
2. Rationale
    The proposed rule would impose different limits on weighted CO 
emission rates for different categories of generators in recognition of 
the effects of factors such as engine size and other engine 
characteristics on CO emissions, in addition to the different 
challenges that may be faced in meeting CO emission rates expressed in 
grams per hour. The proposed rule would apply different criteria to 
generators, based on EPA's classification of engines (and on the number 
of engine cylinders), rather than on power ratings of either the 
generators or the engines. This determination was based mainly on the 
absence of standard methods for defining the rated power, maximum 
power, or surge power of generators. Furthermore, staff determined that 
the technically feasible emission rates were different for different 
categories of generators. Staff also found differences in hazard 
patterns for different categories; this is reflected in the 
determination of epidemiological benefits (for example more fatalities 
associated with large generators involved their use in garages as 
opposed to basements, while for small generators the reverse was true, 
as described in detail in staff's briefing package in Tab K).
    The requirements of the proposed rule are based on technically 
feasible emission rates and an analysis of the benefits and costs 
associated with these technically feasible emission rates. The benefits 
analysis and cost analysis are explained in detail in Section VI and 
Section X, respectively, of this preamble.

D. Test Procedures--Sec.  1241.4

    The proposed rule details the test procedure that the Commission 
would use to determine compliance with the standard, but also provides 
that any test procedure that will accurately determine the emission 
level of the portable generator may be used.
    The procedure the Commission would use is largely based on a test 
method that was developed in a collaborative effort with industry 
stakeholders and is explained in greater detail in Tab J of the 
briefing package. In brief, the Commission intends to perform the tests 
in ambient temperature in the range of 10-38 [deg]C (50-100 [deg]F) 
using E10 gasoline. The six loads that will be applied to the generator 
for determining the weighted CO emission rate are based on the 
generator's maximum load capability. Maximum load capability is 
determined by increasing the load applied to the generator to the 
maximum observed power output, without causing the voltage or frequency 
to deviate by more than 10 percent of the nameplate rated voltage and 5 
percent of the nameplate rated frequency and can be maintained for 45 
minutes with stable oil temperature. The loads will be applied using a 
resistive load bank capable of achieving each specified load condition 
to within 5 percent and will be measured using a power meter with an 
accuracy of  5 percent. The Commission will use constant 
volume sampling (CVS) emissions measurement equipment, as described in 
the EPA's regulations 40 CFR part 1054 and 40 CFR part 1065 as of 2016. 
If the generator is equipped with an economy mode or similar feature 
that has the engine operating in low speed when not loaded, the setting 
that produces the highest weighted CO emission rate will be used to 
verify whether the applicable carbon monoxide emissions rate is met.

E. Prohibited Stockpiling--Sec.  1241.5

    In accordance with Section 9 of the CPSA, the proposed rule 
contains a provision that prohibits a manufacturer from ``stockpiling'' 
or substantially increasing the manufacture or importation of 
noncomplying generators between the date of the final rule and its 
effective date (or compliance date, in the case of generators with 
handheld and Class I engines). The rule would prohibit the manufacture 
or importation of noncomplying portable generators by engine class in 
any period of 12 consecutive months between the date of the 
promulgation of the rule and the effective/compliance date at a rate 
that is greater than 125 percent of the rate at which they manufactured 
or imported portable generators with engines of the same class during 
the base period for the manufacturer. The base period is any period of 
365 consecutive days, chosen by the manufacturer or importer, in the 5-
year period immediately preceding the promulgation of the final rule.
    Generator sales can vary substantially from year to year, depending 
upon factors such as widespread power outages caused by hurricanes and 
winter storms. Annual unit shipment and import data obtained by CPSC 
staff show that it has not been uncommon for shipments to have varied 
by 40 percent or more from year to year at least once in recent years. 
The 5 year period in the anti-stockpiling provision is intended to 
allow manufacturers and importers sufficient flexibility to meet normal 
changes in demand that may occur in the period between the promulgation 
of a rule and its effective/compliance date while limiting their 
ability to stockpile noncomplying generators for sale after that date. 
Allowing manufacturers to produce noncomplying generators in amounts 
that total 125 percent of their peak 365-day period over the prior 5 
years could give manufacturers enough flexibility to respond to demand 
if there is a year of major power outages that create a demand for 
consumers to purchase portable generators. The Commission is aware of 
some large manufacturers that have seen year-to-year shipments increase 
by 50 percent and 70%, so the Commission believes that the allowable 
stockpiling percentage over a base period should be greater for 
generators than most other consumer products. The Commission

[[Page 83582]]

seeks comments on the proposed product manufacture or import limits and 
the base period.

F. Findings--Sec.  1241.6

    In accordance with the requirements of the CPSA, we are proposing 
to make the findings stated in section 9 of the CPSA. The proposed 
findings are discussed in section XVI of this preamble.

X. Preliminary Regulatory Analysis

    The Commission is proposing to issue a rule under sections 7 and 9 
of the CPSA. The CPSA requires that the Commission prepare a 
preliminary regulatory analysis and that the preliminary regulatory 
analysis be published with the text of the proposed rule. 15 U.S.C. 
2058(c). The following discussion is extracted from staff's memorandum, 
``Draft Proposed Rule Establishing Safety Standard for Portable 
Generators: Preliminary Regulatory Analysis.''

A. Introduction

    The CPSC is issuing a proposed rule for portable generators. This 
rulemaking proceeding was initiated by an ANPR published in the Federal 
Register on December 12, 2006. The proposed rule includes weighted 
carbon monoxide emission limits from four different categories of 
portable generators.
    Following is a preliminary regulatory analysis of the proposed 
rule, including a description of the potential costs and potential 
benefits.

B. CPSC Staff Assessment of the Adequacy of Voluntary Standards for 
Portable Generators in Addressing CO Deaths and Injuries

    As indicated in Section VII.B of this preamble, two organizations, 
Underwriters' Laboratories, Inc. (UL), and the Portable Generator 
Manufacturers Association (PGMA), have been accredited by the American 
National Standards Institute (ANSI) to develop U.S. safety standards 
for portable generators. Although each organization has developed a 
standard (designated as UL 2201 and PGMA G300, respectively), only 
PGMA's standard has achieved the consensus needed to be recognized by 
ANSI (as ANSI/PGMA G300-2015). A UL 2201 task group has been working on 
developing proposals to address CO hazards of portable generators; 
however, the task group has not yet sent a proposal to the standards 
technical panel established by UL to consider for adoption into UL 
2201. The current version of UL 2201 includes the mandatory CPSC label, 
but does not otherwise address the risks related to CO poisoning. In 
the Commission's view, the label alone is insufficient to address the 
risk of injury from CO poisoning. CPSC is unaware of any portable 
generator that has been certified to UL 2201. Therefore, it is unlikely 
whether there would be substantial compliance with UL 2201 if the 
standard were to incorporate CO emissions requirements (Buyer, 2016b).
    PGMA G300 also includes the mandatory CPSC label for portable 
generators, but it does not otherwise address the risks related to CO 
poisoning. In a letter emailed to Chairman Kaye on September 19, 2016, 
PGMA announced its intention to reopen G300 to develop a ``performance 
strategy focused on CO concentrations.'' As discussed in Section VII.B 
of this preamble, the Commission does not have an adequate basis to 
determine that PGMA's modification to G300 would likely eliminate or 
reduce the risk of injury or that there likely will be substantial 
compliance with the voluntary standard, once modified. In addition, 
based on the complex nature of setting CO limits and the fact that G300 
is just now being re-opened, the Commission is not convinced that a 
modification to the voluntary standard adequately addressing the risk 
of injury identified in the rulemaking would be accomplished within a 
reasonable period of time. CPSC believes that significant technical 
work, requiring significant time, would be required to develop 
appropriate requirements and test methods within the broad framework 
identified in the PGMA letter \80\ and at a September 6, 2016, public 
meeting between PGMA and staff.\81\ Specifically, as discussed at the 
meeting and in the NPR briefing memorandum, there are several technical 
concerns about shutoff criteria and testing that would need to be 
investigated (Buyer, 2016a). The Commission is concerned whether the 
test methodologies would be accurate, dependable and practicable and 
sufficient to ensure that the generators would shut off quickly enough 
in a sufficient number of common scenarios seen in portable generator 
incidents to result in an adequate reduction in the risk of injury and 
death. The Commission expects that significant periods of time will be 
needed to evaluate each of these factors. For example, determining the 
expected epidemiological benefits for the proposed rule required nearly 
a year for NIST to conduct a modeling study and for staff to evaluate 
the study. For the PGMA to develop an effective voluntary standard, 
similar efforts will be required to assess the standard after the 
technical details have been established.
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    \80\ https://www.cpsc.gov/s3fs-public/PGMALtrChairKayeVoluntaryStandardFinal.pdf.
    \81\ https://www.cpsc.gov/s3fs-public/09%2006%2016%20Meeting%20with%20PGMA%20Follow%20up%20on%20Technical%20Summit%20on%20Carbon%20Monoxide%20Hazard%20Mitigation%20for%20Portable%20Generators.pdf.
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C. Market Information

1. Manufacturers
    Based on data obtained from Power Systems Research, Inc. (``PSR''), 
a total of 78 domestic or foreign manufacturers produced or exported 
gasoline-powered portable generators for the U.S. market in recent 
years. However, most of these manufacturers were based in other 
countries. The Commission has identified 20 domestic manufacturers of 
gasoline-powered portable generators, 13 of which would be considered 
small businesses based on the Small Business Administration (``SBA'') 
size guidelines for North American Industry Classification System 
(``NAICS'') category 335312 (Motor and Generator Manufacturing), which 
categorizes manufacturers as small if they have fewer than 1,250 
employees.
    Few of the 78 firms involved in production for the U.S. market in 
recent years have held significant market shares: Less than half of 
these firms have reportedly had annual shipments of 1,000 units of 
more, and only six firms have had annual shipments of 50,000 units or 
more. From 2009 through 2013, the top five manufacturers combined for 
an estimated 62 percent of the U.S. market for portable generators with 
power ranges more likely to be in consumer use and the top 10 
manufacturers combined for about 84 percent of unit sales during that 
period. Under the CPSA, firms that import generators from foreign 
producers would be considered manufacturers of the products. A review 
of import records for portable generators found that the annual number 
of individual importers of record has ranged from about 25 to 30 in 
recent years. These firms would be responsible for certifying that the 
products they import comply with the rule, should it be finalized by 
the Commission.
2. Annual Shipments/Sales of Portable Generators
    CPSC Directorate for Economic Analysis staff acquired information 
on annual unit sales of portable generators through contract purchases 
from market research firms, from federal data sources (e.g., the 
International Trade Commission [ITC] and Bureau of the

[[Page 83583]]

Census), and other sources.\82\ Chart 1 presents information on sales 
of portable generators for 1995 through 2014. Sales estimates are based 
on estimated portable generator shipments and projected shipments to 
U.S. retailers for the years 1998-2002 and 2007-2013 (RTI 
International, 2006; \83\ Power Systems Research, 2012, 2013); \84\ and 
estimated U.S. consumer purchases of portable generators for 1995-1997 
and 2004-2008 (Synovate, 1999, 2006, 2009).
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    \82\ Power Systems Research, compiled information on domestic 
production and imports of portable generators from its OE 
LinkTM market intelligence database of original equipment 
and original equipment manufacturer (OEM) production & forecast 
data. Synovate (which was purchased by another market research firm, 
Ipsos, in 2011), based on analysis of surveys of the firm's 
Continuing Consumer Survey panel and the firm's Multi-Client 
Research Group (SMRG) sample.
    \83\ RTI International (2006, October), Industry Profile for 
Small Nonroad Spark-Ignition Engines and Equipment--revised draft 
report. Authored by Alex Rogozhin, William White & Brooks Depro.
    \84\ Power Systems Research, Inc. (2012, 2013), Excel data file: 
OE LinkTM original equipment database, portable generator 
sets produced and sold in the United States, Attached to email from 
Marilyn Tarbet, PSR, to Charles Smith, Directorate for Economic 
Analysis, CPSC, October 3, 2012, Excel data file: OE 
LinkTM original equipment production--forecast database 
with sales data, portable generators produced outside of the United 
States, sold in the United States, Attached to email from Marilyn 
Tarbet, PSR, to Charles Smith, Directorate for Economic Anaylsis, 
CPSC, October 4, 2013.
[GRAPHIC] [TIFF OMITTED] TP21NO16.007

    As shown by the chart, consumer demand for portable generators from 
year to year fluctuates with power outages, such as those caused by 
hurricanes and other storms along the Gulf and Atlantic coasts and by 
winter storms in other areas. Periods of increased demand for portable 
generators may be followed by reduced demand because a larger 
percentage of households had made recent purchases. Evidence of the 
importance of weather-related power outages in driving demand for 
portable generators was highlighted in the fiscal 2007 annual report 
issued by Briggs & Stratton, a leading manufacturer of engines used in 
the production of generators (its own and others). The report, noted 
that for 2007, the company had ``a 66% reduction of engine shipments 
for portable generators caused by a lack of events, such as hurricanes, 
that cause power outages'' (Briggs & Stratton, 2007). Additionally, 
spurred by widespread concerns over the possible impact of Y2K in 
disrupting power supplies, estimated portable generator shipments rose 
to about 2.2 million in 1999, still the highest year for estimated 
sales (RTI, 2006).
3. Product Characteristics of Portable Generators Shipped in Recent 
Years
Power Ratings
    Data obtained by the Commission in recent years show that portable 
generators purchased by consumers and in household use generally range 
from under 1 kW of rated power up to perhaps 15 kW of rated power. The 
Commission believes that the most powerful portable generators are 
mainly purchased for construction or commercial use, although some also 
end up in household use.\86\ In Table 6, we present information on 
generator power ratings for shipments of portable generators powered by 
Class I or Class II engines for the U.S. market for the years 2010 
through 2014, based on Commission analysis of data obtained from PSR, 
import data from the U.S. International Trade Commission, and 
information provided by individual firms. The generators are separated 
into six power-rating categories. Over this 5-year period for 
shipments, about 6.9 million gasoline-powered portable generators were 
shipped for consumer use, or an average of about 1.4 million units per 
year. Shipments of nearly 1.6

[[Page 83584]]

million units in 2013, made 2013 the peak year for sales during this 
period.
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    \86\ Although generator power ratings are only known for about 
48 percent of the units involved in death reports as of May 21, 
2015, for the period of 2004 through 2012, fewer than 3 percent of 
these units had power ratings of 8 kW or greater, and the most 
powerful unit involved was 10 kW (Hnatov. 2014).
---------------------------------------------------------------------------

    Data on recent portable generator shipments, as shown in Table 6, 
compared to information on consumer purchases before 2010, indicate 
that the U.S. market has shifted toward smaller, less powerful units. 
Synovate surveys on generators purchased by consumers from 2004 to 
2006, found that about 9 percent of units likely purchased for consumer 
use (< 15kW) had continuous electrical outputs of under 2 kW and about 
12 percent had ratings of 2-3.49 kW (Synovate, 2008). Data acquired 
from PSR and individual manufacturers on portable generator shipments 
in more recent years show that units with power ratings of under 2 kW 
comprised an estimated 21 percent of the market, and units with power 
ratings of 2-3.49 kW have held an estimated market share of about 36 
percent over 2010 to 2014 (as shown in Table 6). The market share of 
larger units, with outputs of 6.5 kW or more, fell from about 22 
percent of the market in 2004 to 2006, to about 9 percent over 2010 to 
2014.\87\
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    \87\ It is possible that some of the demand for generators with 
greater power in recent years has been increasingly met by sales and 
installation of stationary stand-by generators.
[GRAPHIC] [TIFF OMITTED] TP21NO16.008

Engine Classes
    Small spark-ignition engines used in the manufacture of portable 
generators are classified (by EPA and for the CPSC proposed rule) 
according to their total cylinder displacement in cubic centimeters 
(cc). Data on this engine characteristic were obtained from PSR and 
individual firms for recent shipments of portable generators, which 
enabled CPSC to estimate engine classes for the kilowatt ranges 
discussed above. Data on shipments of portable generators for 2010 
through 2014 show that portable generators with Class I engines (those 
with a total cylinder displacement of <225 cc) comprised about 59 
percent of units shipped, and those with Class II engines (those with 
total displacement >=225 cc) comprised about 41 percent. We estimate 
that total annual shipments of portable generators over 2010 to 2014 
averaged almost 1.4 million units; about 816,000 of these generators 
had Class I engines and about 568,000 had Class II engines.
    Although sometimes used in non-handheld equipment (such as portable 
generators), engines are classified as handheld by EPA if they have 
total displacement of less than or equal to 80 cc. Based on information 
provided by PSR and individual firms, we estimate that generators with 
handheld engines account for an average of about 10,000 to 20,000 units 
sold annually; about 1 percent of the overall consumer market for 
portable generators; and perhaps 2 percent of the units with smaller 
(<225 cc) engines.
    Chart 2 shows the relationship between rated kilowatt power of 
portable generators and their engine classes for 2010 through 2014. As 
can be seen, generators with rated power of under 2 kW were made with 
Class I engines; and virtually all of those with rated power of 5 kW or 
greater were made with Class II engines. For units with 2 to 3.49 kW 
(which was the largest single kW category, accounting for 36 percent of 
units in 2010 to 2014), the great majority (93%) were made

[[Page 83585]]

with Class I engines, while a majority (63%) of units with rated power 
in the range of 3.5 to 5 kW were made with Class II engines.
[GRAPHIC] [TIFF OMITTED] TP21NO16.009

Engine Cylinders
    Engines used in the manufacture of portable generators intended for 
consumer use have either one or two cylinders for combustion of fuel. 
Based on information on engine characteristics gathered and reported by 
PSR, virtually all of the portable generators with sustained power 
ratings below 6.5 kW that were sold from 2010 to 2014 were powered with 
one-cylinder engines. These power categories comprised about 91 percent 
of all units purchased by consumers during that period, as shown in 
Table 1. PSR data reveal that one-cylinder engines powered about 91 
percent of the generators with 6.5 to 7.99 kW and about 58 percent of 
units with power ratings from 8 to 9.99 kW. It is in more powerful 
generators, with sustained power ratings of 10 kW and greater, that 
two-cylinder engines are more common, accounting for about 93 percent 
of units sold from 2010 to 2014. Overall, the data indicate that one-
cylinder engines were used in the manufacture of at least 95 percent of 
total unit sales of portable generators to consumers, and in about 89 
percent of the Class II engines used to produce portable generators.
Fuel Distribution Systems
    The Commission believes that compliance with the CO emission 
requirements of the proposed rule likely would lead OEM manufacturers 
of portable generators to select engines that have fuel distribution 
systems that are more capable of controlling air-to-fuel ratios than 
traditional carbureted systems.\88\ Specifically, manufacturers are 
expected to switch to use of electronic fuel injection (EFI) instead of 
conventional carburetors to control the delivery of gasoline to the 
pistons of generator engines. The Commission is aware of at least five 
portable generator manufacturers that have either developed models with 
EFI for evaluation or actually marketed such models within the last 2 
years; and some of these models have been evaluated by the Commission 
at the National Product Test and Evaluation Center.\89\ However, 
virtually all generators currently in consumer use have carbureted fuel 
distribution systems.
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    \88\ Tab I of staff's briefing package.
    \89\ See Tab J of staff's briefing package.
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Engine Cycles
    Spark-ignition engines used in portable generators have either two 
or four piston strokes per combustion cycle. Two-stroke engines have 
simpler designs with fewer moving parts, making them easier to maintain 
and lighter in weight at a given displacement than four-stroke engines. 
They also reportedly can produce up to 40 percent more power than four-
stroke engines with the same displacement (MECA, 2009). These 
characteristics, and the ability to operate in many directions without 
flooding, make two-stroke engines attractive for use in handheld 
equipment, such as chainsaws, trimmers and leaf-blowers. Portable 
generators and other larger non-handheld equipment, such as lawn and 
garden equipment and pressure-washers, typically have 4-stroke engines. 
Although all of the portable generators reported in PSR's database of 
recent shipments had 4-stroke engines, the Commission found portable 
units with small (<80 cc) 2-stroke engines advertised for sale on 
internet Web sites. These units likely comprise an extremely small 
share of the market for portable generators.

[[Page 83586]]

Retail Prices
    With the wide range of engine power and other features available on 
portable generators shipped in recent years, these products also have 
been offered to consumers at a wide range of retail prices. The most 
recent survey data on retail prices was provided to the Commission by 
Synovate and covered the years 2004 through 2006. Consumer survey data 
developed by Synovate found that the average retail price paid by 
consumers for portable generators intended primarily for backup power 
in the event of electric power outages (the primary stated purpose for 
the purchase by about 75% of consumers) was about $1,040 in 2006.
    More recent pricing information was gained through an informal 
survey of advertised prices for portable generators by CPSC staff in 
October 2015 (which included units available in stores and via the 
Internet). This survey found that that retail prices generally vary by 
kW rating of the units, engine class and number of cylinders. For rated 
generator power, average prices were $393 for units under 2 kW; $606 
for 2 to 3.49 kW generators; $640 for 3.5 to 4.99 kW units; $936 for 
those with 5 to 6.49 kW ratings; $1,002 for units with 6.5 to 7.99 kW 
ratings; and $1,745 for units with kW ratings of 8 or more. Generator 
characteristics other than power ratings also affect price. For 
example, ``inverter generators'' have electronic and magnetic 
components that convert the AC power to DC power, which is then 
``inverted'' back to clean AC power that maintains a single phase, pure 
sine wave at the required voltage and frequency suitable for powering 
sensitive equipment, such as computers. These additional components add 
to the manufacturing cost, resulting in significantly higher retail 
prices than units with similar power outputs. For example, our limited 
retail price survey found that the average retail prices of generators 
with power ratings of under 2 kW were $242 for units not identified as 
inverters and $710 for those identified as inverters.
    Regarding retail price information by engine class and number of 
cylinders, staff's informal survey found that generators with handheld 
engines ranged in price from $133 to $799, with an average price of 
about $324. Generators with non-handheld Class I engines had a wide 
price range, from $190 to more than $2,000, with an average price of 
$534. Generators with one-cylinder Class II engines ranged in price 
from $329 to $3,999, with an average price of $1,009. Generators with 
two-cylinder Class II engines ranged in price from $1,600 to $4,999, 
and the average price of these units was $2,550.
    Table 7 shows selected characteristics (displacement, power rating, 
price and weight) for generators found in an informal retail market 
survey of generators, by engine class and type. 
[GRAPHIC] [TIFF OMITTED] TP21NO16.010

D. Portable Generators in Use

    In this section, we estimate the population of portable generators 
in use, averaged over the period 2004 to 2012, analyzed by the 
Directorate for Epidemiology, Division of Hazard Analysis.\90\ 
Estimates of the number of generators in use represent a measure of

[[Page 83587]]

risk exposure and is the necessary first step in calculating product-
related risks (e.g., generator-related deaths and injuries divided by 
the population of generators in use), determining the per-unit societal 
costs of deaths and injuries that would be addressed by the proposed 
standard, and finally, estimating the possible benefits of the proposed 
rule.
---------------------------------------------------------------------------

    \90\ Tab A of staff's briefing package.
---------------------------------------------------------------------------

    We estimated the population of portable generators in use with the 
CPSC's Product Population Model (PPM), a computer model that projects 
the number of products in use, given estimates of annual product sales 
and their expected product life.\91\ The expected useful life of 
generators, in years, is largely a function of engine size, loads 
placed upon the unit and hours of use. Portable generators primarily 
purchased for household backup power that are mainly used during 
occasional or rare power outages could have useful lives much longer 
than 10 years if they are maintained properly. An evaluation of data on 
historical sales in relation to surveys of product ownership suggests 
an expected useful product life of about 11 years. An assumption of a 
considerably shorter expected useful life using data on historical 
annual unit shipments would yield estimated numbers of units in use and 
saturation rates that are well below those indicated by Synovate survey 
data from 2005, as well as industry estimates of ownership in recent 
years.\92\
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    \91\ Lahr, M.L. & Gordon, B.B. (1980). Product life model 
feasibility and development study. Contract CPSC-C-79-009, Task 6, 
Subtasks 6.01-6.06). Columbus, OH: Battelle Columbus Laboratories.
    \92\ For example, portable and stationary generator 
manufacturer, Generac, reportedly estimated that about 12 percent of 
households had portable generators in 2013, up from 10 percent in 
2010 (Hill, 2013).
---------------------------------------------------------------------------

    Table 8 presents the product population estimates for the years 
2004 through 2012; estimated totals have increased from about 9.9 
million in 2004, to about 12.5 million in 2012. The average for the 
years 2004 to 2012 was about 11 million units in use. Table 8 also 
presents estimates of the numbers of portable generators in use by 
ranges of kW ratings. These estimates were based on (1) portable 
generator shipment and purchase data provided by PSR and Synovate for 
the years 2004 through 2013, augmented by estimates of annual sales 
developed for some individual manufacturers; and (2) estimates of 
aggregate annual sales for prior years, in combination with Synovate 
estimates of market shares for the various power categories for 
previous years. The PPM was then used to estimate the product 
population for each power category, assuming an 11-year average product 
life. According to the population estimates, the largest power category 
was generators 5 to 6.49 kW, accounting for an average of 3.6 million 
units in use, or about 33 percent of the total, followed by generators 
3.5 to 4.99 kW (averaging about 2 million units and 18.2% of the 
total).
[GRAPHIC] [TIFF OMITTED] TP21NO16.011

    Note that the estimates provided in Table 8 assume uniform expected 
product lives across engine sizes and power ratings; that is, the 
generators with smaller engine sizes are assumed to last as long as the 
larger engine sizes. Larger engines usually are rated for more hours of 
operation than smaller engines. Assuming the hour ratings reflect the 
relative differences in total hours of actual use, our estimates imply 
fewer hours of use per year for smaller generators versus larger units 
over their useful lives. This issue is addressed in the sensitivity 
analysis, and information regarding product lives of units and average 
annual hours of operation

[[Page 83588]]

would be welcome from industry and the public.
    The proposed rule specifies different requirements for CO emission 
rates depending on generator engine class and other objective 
characteristics, rather than engine or generator power ratings. The 
Directorate for Economic Analysis has estimated historical sales of 
generators by engine class from estimated sales by kW ratings using 
data from PSR reporting both generator power and engine displacement. 
Table 9 presents estimated units in use for 2004 to 2012, by engine 
class. Based on our analysis, the proportion of generators with smaller 
engines (handheld and Class I) has increased over the 9-year period. 
This is consistent with estimates of the increasing share of generators 
in use with power ratings of under 3.5 kW, shown in Table 8, which 
follows from the information presented regarding the apparent shift in 
the U.S. market towards smaller, less powerful units.
[GRAPHIC] [TIFF OMITTED] TP21NO16.012

E. Benefit--Cost Analysis

    This section of the analysis consists of a comparison of the 
benefits and costs of the proposed rule. The analysis is conducted from 
a societal perspective, considering all of the significant costs and 
health outcomes. Benefits and costs are calculated on a per-product-in-
use basis. The benefits are based on the reduced risk of fatal and 
nonfatal injury due to CO poisoning involving portable generators. The 
costs are defined as the added costs of making the portable generators 
comply with the proposed rule.
    Our primary outcome measure is the expected net benefits (i.e., 
benefits minus costs) of the proposed rule. As noted above, our primary 
analysis calculates the benefits and costs of the rule on a per-
product-in-use basis. However, aggregated estimates of the benefits and 
cost on an annual basis can be readily calculated, given projections of 
annual generator sales.
1. Societal Costs of Portable Generator Deaths and Injuries
    As discussed in Section III, the Directorate for Epidemiology, 
Division of Hazard Analysis (EPHA) reports that there were 659 deaths 
involving portable generators from 2004 to 2012, an average of about 73 
annually.\93\ The average annual societal costs of these CO deaths are 
estimated to be about $637 million in 2014 dollars, based on a value of 
a statistical life (VSL) of $8.7 million.\94\
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    \93\ Tab A of staff's briefing package.
    \94\ The estimated value of a statistical life (VSL) of $8.7 
million (in 2014 dollars) is a revision of the VSL estimated by the 
U.S. Environmental Protection Agency and is generally consistent 
with other estimates based on willingness-to-pay. Kneiser et al. 
(2012), suggested that a reasonable range of values for VSL was 
between $4 million and $10 million (in 2001 dollars), or about $5.3 
million to $13.3 million in 2014 dollars (BLS 2015).

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[[Page 83589]]

    EPHA also provided an estimate of CO-related injuries involving 
portable generators, based on estimates from the National Electronic 
Injury Surveillance System (NEISS) during the years 2004 through 
2012.\95\ According to EP, there was a minimum of 8,703 nonfatal CO 
poisonings involving portable generators that were treated in hospital 
emergency departments from 2004 through 2012, or a minimum of about 967 
annually.\96\ This NEISS estimate is considered a minimum because the 
estimate only included injuries that were explicitly attributed to CO 
poisoning injuries in the NEISS narrative.
---------------------------------------------------------------------------

    \95\ Stephen Hanway, Division Director, Division of Hazard 
Analysis, Directorate for Epidemiology, CPSC. Memorandum to Gregory 
B. Rodgers, AED, Directorate for Economic Analysis, CPSC: ``Injuries 
associated with generators seen in emergency departments with 
narratives indicative of CO poisoning 2004-2012 for injury cost 
modeling,'' October 6, 2015.
    \96\ Tab H of staff's briefing package.
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    The NEISS injury estimates are limited to individuals initially 
treated in hospital emergency departments. However, the CPSC's Injury 
Cost Model (ICM) uses empirical relationships between the 
characteristics of injuries and victims in cases initially treated in 
hospital emergency departments and those initially treated in other 
medical settings (e.g., physicians' offices, ambulatory care centers, 
emergency medical clinics), based primarily on data from the Medical 
Expenditure Panel Survey,\97\ to estimate the number of medically 
attended injuries that were treated outside of hospital emergency 
departments. The ICM also analyzes data from the Nationwide Inpatient 
Sample of the Healthcare Cost and Utilization Project \98\ to project 
the number of direct hospital admissions bypassing the hospital 
emergency departments. According to the ICM estimates, there were an 
additional 16,660 medically attended injuries during 2004 to 2012, or 
about 1,851 annually. Consequently, based on NEISS and ICM estimates, 
there was a minimum of about 2,818 medically attended injuries (967 ED 
+ 1,851 non-ED) treated annually during the 9-year period.
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    \97\ The Medical Expenditure Panel Survey (MEPS) is a nationally 
representative survey of the civilian non-institutionalized 
population that quantifies individuals' use of health services and 
corresponding medical expenditures. The MEPS is administered by the 
Agency for Healthcare Research and Quality (AHRQ). The MEPS has been 
collected continuously since 1999 and is the principal data set used 
to monitor medical spending in the U.S.
    \98\ The National (Nationwide) Inpatient Sample (NIS) is part of 
a family of databases and software tools developed for the 
Healthcare Cost and Utilization Project (HCUP). The NIS is the 
largest publicly available all-payer inpatient health care database 
in the United States, yielding national estimates of hospital 
inpatient stays. HCUP is a family of health care databases and 
related software tools and products developed through a Federal-
State-Industry partnership and sponsored by the Agency for 
Healthcare Research and Quality (U.S. Department of Health & Human 
Services).
---------------------------------------------------------------------------

    The ICM is fully integrated with NEISS and provides estimates of 
the societal costs of injuries reported through NEISS, as well as the 
costs associated with the estimated medically attended injuries treated 
outside of hospital emergency departments. The major aggregated 
societal cost components provided by the ICM include medical costs, 
work losses, and the intangible costs associated with lost quality of 
life or pain and suffering.
    Medical costs include three categories of expenditures: (1) Medical 
and hospital costs associated with treating the injury victim during 
the initial recovery period and in the long run; the costs associated 
with corrective surgery; the treatment of chronic injuries, and 
rehabilitation services; (2) ancillary costs, such as costs for 
prescriptions, medical equipment, and ambulance transport; and (3) 
costs of health insurance claims processing. Cost estimates for these 
expenditure categories were derived from a number of national and state 
databases, including the Medical Expenditure Panel Survey, the 
Nationwide Inpatient Sample of the Healthcare Cost and Utilization 
Project, the Nationwide Emergency Department Sample,\99\ the National 
Nursing Home Survey,\100\ MarketScan[supreg] \101\ claims data, and a 
variety of other federal, state, and private data.
---------------------------------------------------------------------------

    \99\ The Nationwide Emergency Department Sample (NEDS) is part 
of a family of databases and software tools developed for the 
Healthcare Cost and Utilization Project (HCUP). The NEDS is the 
largest all-payer emergency department (ED) database in the United 
States, yielding national estimates of hospital-based ED visits.
    \100\ The National Nursing Home Survey (NNHS) is a series of 
nationally representative sample surveys of United States nursing 
homes, their services, their staff, and their residents. The NNHS 
was first conducted in 1973-1974 and repeated in 1977, 1985, 1995, 
1997, 1999, and most recently in 2004.
    \101\ The MarketScan[supreg] Commercial Claims and Encounters 
(MarketScan) Database from Truven Health Analytics contains de-
identified, person-specific health data of reimbursed healthcare 
claims for employees, retirees, and their dependents of more than 
250 medium and large employers and health plans.
---------------------------------------------------------------------------

    Work loss estimates are based on information from the Nationwide 
Inpatient Sample of the Healthcare Cost and Utilization Project, the 
Nationwide Emergency Department Sample, Detailed Claims Information (a 
workers' compensation database), the National Health Interview Survey, 
the U.S. Bureau of Labor Statistics and other sources. These estimates 
include: (1) Forgone earnings of the victim, including lost wage work 
and household work; (2) forgone earnings of parents and visitors, 
including lost wage work and household work; (3) imputed long-term work 
losses of the victim that would be associated with permanent 
impairment; and (4) employer productivity losses, such as the costs 
incurred when employers spend time juggling schedules or training 
replacement workers.
    Intangible, or noneconomic, costs of injury reflect the physical 
and emotional trauma of injury, as well as the mental anguish of 
victims and caregivers. Intangible costs are difficult to quantify 
because they do not represent products or resources traded in the 
marketplace. Nevertheless, they typically represent the largest 
component of injury cost and need to be accounted for in any benefit-
cost analysis involving health outcomes.\102\ The ICM develops a 
monetary estimate of these intangible costs from jury awards for pain 
and suffering. Although these awards can vary widely on a case-by-case 
basis, studies have shown them to be systematically related to a number 
of factors, including economic losses, the type and severity of injury, 
and the age of the victim (Viscusi, 1988; Rodgers, 1993).\103\ 
Estimates for the ICM were derived from regression analysis of jury 
awards compiled by Jury Verdicts Research, Inc., for nonfatal product 
liability cases involving consumer products.
---------------------------------------------------------------------------

    \102\ Rice, D., MacKenzie, E. & Associates (1989). Cost of 
injury in the United States: A report to Congress. San Francisco, 
CA: Institute for Health & Aging, University of California and 
Injury Prevention Center, The Johns Hopkins University.
    \103\ Viscusi, W.K. (1988). The determinants of the disposition 
of product liability cases: Systematic compensation or capricious 
awards? International Review of Law and Economics, 8, 203-220; 
Rodgers, G. (1993). Estimating jury compensation for pain and 
suffering in product liability cases involving nonfatal personal 
injury. Journal of Forensic Economics 6[euro], 251-262.
---------------------------------------------------------------------------

    According to the ICM, the estimated injury costs of the 
approximately 2,817 medically attended portable generator CO injuries 
annually amounted to about $184 million (in 2014 dollars), an estimated 
average of $65,400 per injury. Medical costs and work losses accounted 
for about 53 percent of the total, while the non-economic losses 
associated with pain and suffering accounted for about 47 percent. The 
societal costs of both fatal and nonfatal CO poisoning injuries 
involving portable generators amounted to about $821 million ($637 
million for fatal

[[Page 83590]]

injuries + $184 million for nonfatal injuries) annually.
    The average annual societal cost estimates for generators in use in 
2004 through 2012, by engine class, are presented in more detail in 
Table 10. Row 1 provides the annual estimates of fatal CO poisoning 
injuries by engine class, and the estimated percent of all deaths 
involving each category. Note that information on engine class for 
generators involved in the deaths was available on only about 48 
percent of the cases. The cases in which the engine classes were not 
known were distributed proportionally to the cases in which the classes 
were known.
    Row 2 shows estimated annual nonfatal injuries by engine class; the 
nonfatal CO injuries were distributed proportionally to the deaths 
because very little information is available on the displacement of 
engines of generators involved in these injuries. Row 3 provides 
estimates of the aggregate annual societal costs of the deaths and 
injuries. Societal costs were based on a VSL of $8.7 million per death, 
and the nonfatal injury costs are from the ICM modeling. Row 4 provides 
the annual estimates of portable generators in use by engine class, as 
well as the estimated percent of all units in use for each category. 
Row 5 provides annual per-unit societal costs of deaths and injuries, 
which is based on the Row 3 estimates divided by the estimated numbers 
of portable generators in use (shown in Row 4).
[GRAPHIC] [TIFF OMITTED] TP21NO16.013

    Finally, Row 6 provides per-unit estimates of the present value of 
the expected societal costs (at a 3% discount rate) over the expected 
product life of a generator. This figure is useful in benefit-cost 
analysis because it represents the maximum per-unit benefits that might 
be derived from a product safety standard, if the standard prevented 
all deaths and injuries. The present value of expected societal costs 
is $687 per unit for portable generators with handheld engines (which 
are estimated to have accounted for less than 1% of units in use during 
the period 2004 through 2012); $672 per unit for generators with Class 
I engines (35.5% of units in use); $758 per unit for generators with 
one-cylinder Class II engines (56.7% of units in use); and $116 per 
unit for generators with two-cylinder Class II engines (7.1% of units 
in use). The societal costs associated with the two-cylinder Class II 
generators are substantially lower than for the other generator 
categories because of the small relative risk for the two-cylinder 
models. Because the two-cylinder models accounted for about 7.1 percent 
of generators in use, but only about 1.2 percent of the deaths, the 
risk of death with two-cylinder generators was only about 16 percent of 
the risk associated with generators with one-cylinder engines (i.e., 
handheld, Class I, and one-cylinder Class II generators). The average 
expected present value of societal costs of CO poisoning deaths and 
injuries for all portable generators is $682 per unit. These 
calculations also represent baseline estimates of the societal costs 
associated with portable generators, by engine class and other 
characteristics: Estimates of what per-unit societal costs would be in 
the absence of regulatory action. Benefits of the proposed rule can, 
therefore, be estimated as the expected reduction in the baseline 
societal costs.
2. Estimated Benefits of the Proposed Rule
    As described in Section IX, the requirements of the proposed 
performance standard require portable generators powered by handheld 
engines and Class I engines to emit CO at a weighted rate that is no 
more than 75 grams per hour (g/hr); generators powered by one-cylinder 
Class II engines to emit CO at a weighted rate that is no more than 150 
g/hr; and generators powered by two-cylinder Class II engines to emit 
CO at a weighted rate that is no more than 300 g/hr. As noted in CPSC 
staff's analysis that provides the rationale for the performance 
requirements, considering expected manufacturing variability of 50 percent, based on limited testing of

[[Page 83591]]

pairs of generators, as described in the staff's briefing package, 
these emission requirements reflect a factor of 1.5 over the expected 
technically feasible emission rates for each engine classification: 50 
g/h for those with handheld and Class I engines; 100 g/h for those with 
one-cylinder Class II engines; and 200 g/h for those with two-cylinder 
Class II engines.\104\ Comments and additional data on expected 
manufacturing variability would be welcome, given the limited data 
available to staff to evaluate variability.
---------------------------------------------------------------------------

    \104\ Tab I of staff's briefing package.
---------------------------------------------------------------------------

    To estimate the expected reduction in societal costs, and hence, 
the benefits from the proposed rule for portable generators, an 
interdisciplinary analysis by CPSC staff provided estimates of 
generator-related consumer CO poisoning deaths reported in the agency's 
databases that could have been avoided as a result of reduced CO 
emission rates from generators. An important part of the analysis was 
indoor air quality modeling by NIST under an interagency agreement to 
estimate the transport of CO emitted from generators and predicted 
health effects for scenarios and house characteristics found in CPSC's 
incident data. CPSC staff then compared the health effects resulting 
from emission rates from current generators to a range of lower CO 
emission rates to estimate deaths that could have been avoided for each 
emission rate.\105\
---------------------------------------------------------------------------

    \105\ See Tab K of staff's briefing package.
---------------------------------------------------------------------------

    The NIST modeling and CPSC staff analysis considered scenarios 
associated with 503 CO poisoning deaths over 2004 to 2012, or about 76 
percent of the 659 CO poisoning deaths in CPSC records over the 9-year 
period. These deaths occurred at various fixed-structure residential 
settings, including traditional houses, mobile homes, townhomes, and 
structures attached to a home, in addition to residential sites where 
generators were operated in separate structures, such as sheds cabins 
used for temporary (non-residential) shelter and detached garages. For 
the purposes of this analysis, deaths and injuries occurring in these 
settings are considered to be those that would be which would be 
addressable by the proposed rule. However, we note that an unquantified 
number of the 156 deaths not modeled by NIST might be addressed and 
prevented by the proposed rule.\106\
---------------------------------------------------------------------------

    \106\ IBID.
---------------------------------------------------------------------------

    Chart 3 presents the results of CPSC staff analyses of estimated 
reductions in CO poisoning fatalities that would result from lower-
weighted emission rates for modeled scenarios under various weighted CO 
emission rates. At each reduced emission rate, the estimated percentage 
reduction in fatalities is greater for generators powered with larger 
engines because of their higher average estimated base rate for CO 
emissions (4700 g/h for one-cylinder and 9100 g/h for two-cylinder 
Class II engines vs 1800 g/h for Class I non-handheld engines and 900 
g/h for handheld engines).\107\ In CPSC engineering staff's judgment, 
the technically feasible weighted CO emission rates are 50 g/h for 
generators powered by handheld and Class I engines, 100 g/h for 
generators powered by one-cylinder Class II engines, and 200 g/h for 
generators with two-cylinder Class II engines.\108\
---------------------------------------------------------------------------

    \107\ These rates assume a factor of 3 in the increase in CO 
emission rate of a generator operating in an enclosed space compared 
to operation outdoors in normal oxygen. This factor of 3 is based on 
testing of carbureted generators conducted by NIST (Emmerich, 
Polidoro & Dols, op. cit.) and CPSC staff (Brookman, 2016, TAB J of 
the NPR Briefing Package).
    \108\ See Tab I of staff's briefing package.
---------------------------------------------------------------------------

    Emission rates from generators meeting the proposed performance 
requirements are expected to be higher while operating indoors (at 
reduced oxygen levels of approximately 17%) than the feasible rates 
under conditions of approximately 20.9% oxygen: Perhaps 150 g/h for 
generators with handheld engines and Class I engines, 300 g/h for 
generators with one-cylinder Class II engines and 600 g/h for 
generators with two-cylinder Class II engines (three times the 
technically feasible rate for each generator category).\109\ Based on 
staff's analysis of 503 deaths (76 percent of all deaths) modeled by 
NIST (and generally deemed to be addressable by the proposed standard), 
these emission rates are expected to result in about a 47 percent 
reduction in (addressable) fatalities involving generators with 
handheld engines; about a 49 percent reduction in fatalities involving 
generators with Class I engines; a 37 percent reduction for those with 
one-cylinder Class II engines: And a reduction of about 17 percent for 
generators with two-cylinder Class II engines. The average expected 
reduction in CO poisoning fatalities across generators of all engine 
types is about 44 percent of the addressable deaths and injuries, or 
about 33 percent of all generator-related deaths and injuries (44% x 
76%).
---------------------------------------------------------------------------

    \109\ Based on CPSC's testing of three generators with fuel-
injected engines having different degrees of closed-loop operation 
(see TAB J of staff's briefing package), CPSC believes the factor of 
increase when the oxygen is 17 percent may be less than 3 for some 
generators that use closed-loop EFI. Furthermore, test results from 
NIST (Buyer, 2012) indicate the prototype EFI generator depleted the 
oxygen significantly less than the carbureted generator, when tested 
in each of four matched-pair identical test scenarios. Nevertheless, 
CPSC assumes in the benefits analysis a conservative factor of 3 for 
the increase in CO emissions for low-emission generators when 
operating at reduce oxygen levels of 17 percent. Therefore, the 
factor of 3 likely overstates the weighted CO emission rates for EFI 
generators when operated indoors, and understates the reduction in 
deaths and injuries resulting from the draft standard.

---------------------------------------------------------------------------

[[Page 83592]]

[GRAPHIC] [TIFF OMITTED] TP21NO16.014

    Table 11 presents estimated reductions in societal costs, and 
hence, benefits of the reduced CO emissions predicted to result from 
the proposed standard. The per-unit societal costs per generator, from 
Table 10, are included at row 1. However, as noted above, not all of 
these costs would be addressed by the proposed standard or were not 
included among the major residential scenarios modeled by NIST.\110\ 
The present value of expected societal costs of CO poisoning that would 
be addressed by an emission standard are shown in row 2 and average 
about $514 for generators with Class I engines and about $586 for 
generators with one-cylinder Class II engines--engine categories that 
combine for an estimated 92 percent of portable generators in use. 
Generators with handheld engines, estimated to account for less than 1 
percent of units in use, are estimated to average $525 in societal 
costs. Generators with two-cylinder Class II engines are estimated to 
average $26 in societal costs of CO poisoning over their useful lives. 
These larger generators are estimated to account for about 7 percent of 
all units in use.
---------------------------------------------------------------------------

    \110\ About 76 percent of all CO poisoning deaths from 2004 to 
2012 involved scenarios that were modeled by NIST. Among the 
scenarios that were not modeled are those involving CO poisoning 
deaths in apartments, vehicles and trailers (non-mobile homes), and 
other structures, such as a church, a sea-land container, and tents.
---------------------------------------------------------------------------

    Row 3 shows the staff's estimates of weighted CO emissions from 
complying generators of the different engine categories that would 
result from operation in conditions of reduced oxygen. Row 4 shows the 
estimated reduction in addressable societal costs resulting from the 
weighted emission rates, based on CPSC staff's estimate of the 
reduction in CO poisoning deaths.\111\ Our estimate of reduction in 
societal costs of CO poisoning deaths and injuries assumes that 
projected injury costs from annual production of generators will fall 
in proportion to estimated death reduction, with a minor adjustment to 
account for the possibility that deaths avoided by reduced CO emissions 
would still occur as injuries.\112\ With projected reductions in deaths 
and injuries under the proposed standard, the present value of benefits 
(shown in row 5 of Table 10) is estimated to average about $243 for 
generators with handheld engines; $254 per unit for generators with 
Class I engines; $214 per unit for generators with one-cylinder Class 
II engines; and $4 for generators with two-cylinder Class II engines. 
Average projected present value of benefits for all portable generators 
is about $227 per unit.
---------------------------------------------------------------------------

    \111\ Tab K of the staff's briefing package.
    \112\ We have assumed that avoided deaths under the proposed 
rule would still occur as nonfatal CO injuries of average severity 
and cost.
---------------------------------------------------------------------------

    Multiplying the present value of expected benefits per unit by 
estimated annual unit sales (in row 6) yields the estimated aggregate 
present value of benefits from annual sales of portable generators that 
would comply with the proposed standard. The estimated present value of 
benefits of reduced CO poisoning from complying portable generators 
sold in a year totals about $315 million. Nearly 99 percent of the 
total benefits are attributable to expected sales of generators with 
Class I engines and one-cylinder Class II engines. These two types of 
engines are expected to comprise about 94 percent of annual unit sales 
under the proposed standard.

[[Page 83593]]

[GRAPHIC] [TIFF OMITTED] TP21NO16.015

    Projections of benefits of the proposed rule should account for 
recent changes, and reasonably expected changes, in the market that 
will affect societal costs and the costs of compliance by 
manufacturers. One consideration that would be expected to reduce the 
addressable societal costs of the rule from those estimated for the 
period of 2004 to 2012 is the relatively recent introduction of units 
with EFI. Increased use of EFI would also reduce the costs of 
compliance with a standard based on reduced CO emissions. However, 
portable generators with EFI have not yet gained a significant share of 
the consumer market for portable generators, and we have little basis 
for incorporating projected sales of EFI units into the analysis. 
Regarding the introduction of EFI on expected hazard costs, most of the 
EFI-equipped portable generators have reportedly not targeted 
reductions in CO emissions, specifically. Therefore, a relatively small 
share of the generator market would not be expected to contribute to 
substantial reduction in the overall hazard. However, costs of 
compliance with a mandatory standard would be greatly reduced for units 
with EFI systems.
    In addition to reducing societal costs related to CO poisoning 
deaths and injuries, product modifications to achieve greatly reduced 
CO emissions could also result in improved fuel efficiency and other 
benefits, including easier starting, altitude compensation, fuel 
adaptability, improved power, better reliability and longer useful 
product life.
3. Estimated Costs of Compliance With the Proposed Rule
a. Costs of Compliance per Unit
    Based on the judgment of CPSC engineering sciences staff, the most 
likely technical means of compliance with the requirements of the 
proposed rule would be the use of closed-loop electronic fuel-injection 
systems to achieve and maintain the needed air-to-fuel ratios under 
different loads and ambient conditions.\113\ Another element expected 
to be part of the industry's technical response to the proposed 
standard is the addition of 3-way catalysts in the muffler systems of 
portable generator engines. Besides achieving further reductions in CO 
emissions, these catalysts would likely serve to reduce HC and 
NOX emissions for continued compliance with EPA emission 
standards for small spark-ignition engines.
---------------------------------------------------------------------------

    \113\ Janet L. Buyer, Technology Demonstration of a Prototype 
Low Carbon Monoxide Emission Portable Generator. U.S. Consumer 
Product Safety Commission, Bethesda, MD. September 2012.
---------------------------------------------------------------------------

    More detailed discussions of the expected product modifications, 
and other factors leading to cost increases, appear in the following 
discussion. All cost estimates are expressed in 2014 dollars, for 
comparison with estimated benefits of the proposed rule.\114\
---------------------------------------------------------------------------

    \114\ Cost estimates are adjusted to 2014 dollars by applying 
changes in the producer price index for riding lawn & garden 
equipment, a product group with similarities to portable generators.
---------------------------------------------------------------------------

(1.) Electronic Fuel Injection (EFI)

    The likely industry switch from engines with carburetors as the 
means of fuel delivery to closed-loop EFI is expected to be the most 
significant factor in determining cost increases under the proposed 
rule. This technology has been used for a number of years on the small 
spark-ignition engines in small motorcycles and scooters, as well as in 
more recent years in a variety of other product applications, including 
lawnmowers/tractors and golf carts. Although some firms have introduced 
portable generators with EFI for the consumer market in the last couple 
of years, generators with this fuel delivery system currently account 
for a very small fraction of sales. Associated components for closed-
loop EFI could include the electronic control unit, fuel pump, 
injector(s), pressure regulator, throttle body, and a variety of 
sensors, such as

[[Page 83594]]

manifold air pressure sensor or throttle position sensor, intake air 
temperature sensor, oil temperature sensor, crank position sensor, and 
related wiring and hardware, and an oxygen sensor for closed-loop 
feedback. According to the EPA, the combined costs of these elements 
for one-cylinder engines (which dominate the market for residential 
generators) are estimated to be about $90 per unit in 2014 
dollars.\115\ Cost savings of about $20 per unit are estimated for 
elimination of the carburetor, yielding estimated net costs of about 
$70 for the EFI components.
---------------------------------------------------------------------------

    \115\ U.S. Environmental Protection Agency (EPA), (2006, July). 
Small SI engine technologies and costs, final report. Prepared by 
Louis Browning and Seth Hartley, ICF International, for the 
Assessment and Standards Division, Office of Transportation and Air 
Quality, EPA. Washington, DC. These cost estimates include original 
equipment manufacturer markups and warranty markups totaling an 
estimated 34 percent; such markups were also included in EPA's cost 
estimates.
---------------------------------------------------------------------------

    The effectiveness of EFI in controlling the air-fuel ratio with 
resulting improved engine combustion efficiency and reduced CO 
emissions was demonstrated by CPSC staff's technology demonstration 
project,\116\ as well as by the EPA.\117\ The EPA's demonstration work, 
which formed the basis of their 2008 analysis of more stringent 
requirements for HC and NOX emissions of small non-road 
spark-ignition engines, provides a basis for our evaluation of this 
technology, specific to portable generators. The EPA estimates are 
largely consistent with other confidential estimates of costs provided 
by manufacturers of generators, as well as by a manufacturer of fuel-
control components during discussions with CPSC staff.
---------------------------------------------------------------------------

    \116\ Janet L. Buyer, Technology Demonstration of a Prototype 
Low Carbon Monoxide Emission Portable Generator. U.S. Consumer 
Product Safety Commission, Bethesda, MD. September 2012.
    \117\ McDonald, Joseph, Olson B, and Murawski M, Demonstration 
of Advanced Emission Controls for Nonroad SI Class II Engines, SAE 
paper 2009-01-1899.
---------------------------------------------------------------------------

    Most CO poisoning deaths from portable generators occur when 
generators are used in enclosed spaces, such as in a closed garage, 
basement, or room in the living space of a house, or in a partially 
enclosed space, such as in a garage with the garage door opened part 
way.\118\ In such scenarios, the spark-ignition engines are likely to 
be operating in conditions of decreasing oxygen concentrations in the 
ambient air. As noted previously, these conditions can make combustion 
less efficient, thereby increasing CO emission rates as the generators 
continue to operate, unless the reduced oxygen level is taken into 
account. CPSC's benefits analysis takes this into consideration by 
noting that both carbureted and closed-loop fuel-injected generators' 
CO emission rates increase as the oxygen in the intake air to the 
generator decreases.\119\ In CPSC staff's view, compliance with these 
performance requirements would likely require the use of an oxygen 
sensor placed in the engine's exhaust stream to provide closed-loop 
feedback to the fuel-control system. The oxygen sensor sends a voltage 
signal to the electronic control unit that varies with the amount of 
oxygen in the engine exhaust. The ECU uses this signal to check that 
the correct amount of fuel is being metered through the fuel injector 
to maintain the air/fuel ratio at or near stoichiometry, which is the 
theoretical point for near-complete combustion and minimized CO 
emissions. The ECU uses the other sensors to determine how much fuel to 
provide, and the oxygen sensor provides feedback on whether or not the 
fuel mixture is correct. In this closed-loop operation, the ECU would 
continually adjust the fuel mixture to maintain complying CO emission 
rates. Based on information developed for EPA when its staff considered 
more stringent requirements for HC and NOX emissions, engine 
manufacturers that incorporate oxygen sensors in the exhaust streams of 
portable generator engines could incur variable costs of about $10 per 
engine (adjusted to 2014 dollars).\120\
---------------------------------------------------------------------------

    \118\ Tab A of the staff's briefing package.
    \119\ See Tabs I and K of the staff's briefing package.
    \120\ U.S. Environmental Protection Agency (EPA) (2008, 
September). Control of emissions from marine SI and small SI 
engines, vessels, and equipment: Final regulatory impact analysis. 
Assessment and Standards Division, Office of Transportation and Air 
Quality. Washington, DC. Page 6-22; As with EFI cost estimates, this 
per-unit cost estimate related to oxygen sensors includes original 
equipment manufacturer and warranty markups totaling 34 percent.
---------------------------------------------------------------------------

    In its assessment of costs of this feature for small spark-ignition 
engines, the EPA (2006) also projected that Class I engines would also 
require batteries and alternators/regulators at estimated additional 
costs totaling about $17 (including original equipment manufacturer and 
warranty markups). As previously noted, data on shipments of portable 
generators for 2010 through 2014 show that portable generators with 
Class I engines comprised about 59 percent of units shipped, and those 
with Class II engines accounted for about 41 percent of units. 
Therefore, the estimated cost increase per unit for the EFI-related 
components identified in this section would be about $94 for generators 
with Class I engines (55% of units); about $79 for generators with one-
cylinder Class II engines (about 36%); and about $85 for generators 
with two-cylinder Class II engines.\121\
---------------------------------------------------------------------------

    \121\ Two-cylinder engines would require two fuel injectors, 
which increases costs versus one-cylinder Class II engines.
---------------------------------------------------------------------------

    We note that it may be technically feasible, and perhaps eventually 
less costly for manufacturers to incorporate EFI systems that power-up 
the fuel pump and electronic components by magnets when starter cords 
are pulled. Battery-less EFI systems have been available in consumer 
products for several years, including snowmobiles, outboard motors, and 
motorcycles. However, we are not aware of the current use of this 
technology in applications with Class I engines. Comments on 
prospective use (e.g., costs, applicability and challenges) of battery-
less EFI for portable generators would be welcome.
(2.) Catalysts in Mufflers
    Generator manufacturers also are likely to include three-way 
catalysts \122\ in the mufflers of generator engines to achieve the low 
CO emission rates that would be required by the proposed standard, and 
still allow compliance with EPA Phase 3 emissions standards for other 
pollutants in ES staff's judgment.\123\ Catalysts assist in chemical 
reactions to convert harmful components of the engine's exhaust stream 
(Hydrocarbons [HC] and oxides of nitrogen [NOX] in addition 
to CO) to harmless gases. According to the Manufacturers of Emission 
Controls Association (MECA), the catalysts perform this function 
without being changed or consumed by the reactions that take place. In 
particular, when installed in the exhaust stream, the catalyst promotes 
the reaction of HC and CO with oxygen to form carbon dioxide and water, 
and the chemical reduction of NOX to nitrogen is caused by 
reaction with CO over a suitable catalyst.\124\
---------------------------------------------------------------------------

    \122\ Three-way catalysts are designed to simultaneously convert 
three pollutants to harmless emissions: Carbon Monoxide [rarr] 
Carbon Dioxide; Hydrocarbons [rarr] Water, and; Oxides of Nitrogen 
[rarr] Nitrogen.
    \123\ Tab I of staff's briefing package.
    \124\ Manufacturers of Emission Controls Association (MECA) 
(2009, January). White Paper: Emission control of small spark-
ignited off-road engines and equipment. Washington, DC. Retrieved 
from: http://www.meca.org/galleries/files/sore_white_paper_0109_final.pdf.
---------------------------------------------------------------------------

    In its assessment of the costs of the Phase 3 emission standards 
for small SI engines, EPA estimated that 3-way catalysts in mufflers of 
one-cylinder engines of portable generators could add about $10 to $20 
in additional hardware costs to the manufacturing costs per engine, 
depending on capacity, power, and useful life.\125\ These estimates 
were

[[Page 83595]]

based on assumptions regarding use of precious metals (principally 
platinum and rhodium), which were not formulated to oxidize CO, and 
their prices in 2005. Based on our analysis of costs, including heat 
shields or double-walled mufflers that could be necessary, catalytic 
mufflers could add about $14 to the manufacturing cost of a Class I 
engine and about $19 to the cost of a Class II engine. These costs 
could vary, depending on choices and assumed loadings of precious 
metals. Recent evaluations of nonprecious metal catalysts by MECA have 
found that these less-costly catalysts perform well in the oxidization 
of CO.\126\ Application of this technology could lead to a reduction in 
costs of compliance related to catalytic after-treatment.
---------------------------------------------------------------------------

    \125\ EPA, op. cit.
    \126\ Kevin Hallstrom. ``Catalyst control of CO from portable 
generators.'' Presentation on behalf of Manufacturers of Emission 
Controls Association (MECA) at the PGMA Technical Summit, March 17, 
2016. Available online (pp. 125-141) at: http://www.cpsc.gov//Global/Newsroom/FOIA/Meeting%20Logs/2016/MeetingLogPGMA31716.pdf.
---------------------------------------------------------------------------

    Although EPA assumed that Class I and Class II engines would 
include catalytic mufflers under Phase 3 emission requirements, a 
majority of small SI engines submitted for EPA certification in recent 
years has not included after-treatment devices, such as catalysts. 
Current engines produced with catalytic after-treatment would incur 
smaller costs for this feature. In the view of CPSC engineering staff, 
portable generators powered by 4-stroke handheld engines might not 
require catalysts to comply with the proposed rule since the catalyst 
in both CPSC's and EPA's demonstration programs was primarily for 
NOX reduction, and handheld engines have less stringent 
NOX emission requirements under EPA emission standards.\127\ 
For purposes of estimating costs, we assume that catalyst-related costs 
for generators with handheld engines would average 50 percent of 
estimated costs for units with Class I engines, or about $7 per 
generator.
---------------------------------------------------------------------------

    \127\ Tab I of staff's briefing package.
---------------------------------------------------------------------------

(3.) Design and Development/Other Reengineering
    In an analysis of small SI engine technologies and costs, ICF 
International estimated that costs of conversion to EFI from 
carburetors would require 4 months of design time (engineers) and 6 
months for development (by engineers and technicians) for Class I 
engines and 2 months for design and 2 months for development for Class 
II engines).\128\ Based on estimated labor costs for engineering/
technical staff, EPA estimated that these design and development costs 
totaled about $175,000 for Class I engines and about $64,000 for Class 
II engines, for each engine family. Design and development costs for 
three-way catalysts in mufflers were estimated by EPA to be about 
$135,000 per engine line for 2 months of design time (engineers) and 5 
months of development time (engineers and technicians). Adjusting for 
changes in an appropriate producer price index, the total design and 
development costs for engines to incorporate EFI and catalysts are 
estimated to be about $316,000 for a Class I engine family and $203,000 
for a Class II engine family. We assume (as EPA did) that these costs 
are recovered over 5 years. If average annual production per-engine 
family ranges from 10,000 to 50,000 units, per-unit design and 
development costs could range from about $1 to $6 for Class I engines 
and under $1 to about $4 for Class II engines.
---------------------------------------------------------------------------

    \128\ EPA (2006), op. cit.
---------------------------------------------------------------------------

    These estimated costs could be applicable for portable generator 
manufacturers that supply their own engines. Engine manufacturers that 
supply engines to independent generator manufacturers might 
successfully pass along research and development costs with markups. 
EPA estimated that manufacturing and warranty markups by suppliers of 
EFI and catalytic components total 34 percent. Similar markups of 
design and development costs by suppliers of complying engines could 
increase generator manufacturing costs by about $2 to $8 for generators 
with Class I engines and by about $3 to $5 for generators with Class II 
engines. Manufacturers of approximately 80 percent of generators supply 
their own engines. Therefore, average generator manufacturing costs for 
design and development could be about $4.05 for generators with Class I 
engines and $2.60 for generators with Class II engines.\129\
---------------------------------------------------------------------------

    \129\ Midpoint estimates for annual engine family production 
ranging from 10,000 to 50,000 units.
---------------------------------------------------------------------------

    Costs of design and development for generators powered by handheld 
engines were not specifically addressed by EPA. For the purposes of 
this preliminary analysis, we assume that these costs will be similar 
to those estimated for units with Class I engines. However, we assume 
that costs per engine family would be apportioned over perhaps 5,000 to 
10,000 units annually. This assumption leads to average generator 
manufacturing costs for design and development of about $10 per unit 
for generators with handheld engines. We also acknowledge that models 
with handheld engines often are valued and promoted for their 
compactness and light weight. Accommodating new features that might be 
necessary for compliance with the proposed rule and still provide these 
desired product characteristics could present greater challenges and 
costs for product engineers and firms. The Commission welcomes comments 
on this issue, as well as on components and technologies that might be 
available to meet these challenges and moderate the impacts of the 
proposed rule on these models.
    Costs of new designs and tooling may also be required for generator 
frames and housings to accommodate additional components, such as 
batteries for generators with Class I engines, and to address reported 
concerns with heat dissipation. Modifications could be minimal for many 
larger generators with open-frame designs; but some smaller units with 
housings that enclose engines and other components could require 
larger, redesigned housings, at greater cost. We have assumed that per-
unit tooling costs for generators with handheld engines would be twice 
that of other generators, but costs may be underestimated for small 
generators. The Commission welcomes comments on this issue from firms 
that would be affected by the rule.
    The modifications to small SI engines to comply with the CO 
emission requirements of the CPSC standard would likely require engine 
manufacturers to seek certifications (as new engine families) under EPA 
requirements for HC+NOX and CO, with the attendant costs for 
fees and testing, which could be passed on to generator manufacturers 
that purchase the engines to power their products. Some of the larger 
manufacturers of portable generators are vertically integrated firms 
that also manufacture the engines that power their products. It is 
possible that engine modifications by engine manufacturers (including 
firms that also manufacture generators) to comply with the CPSC 
emission standards for CO could result in emissions of 
HC+NOX that are consistently lower than the EPA emission 
requirements. This potential effect of the use of EFI and catalysts was 
shown by demonstration programs sponsored by CPSC (conducted by the 
University of Alabama) and EPA, as detailed in the CPSC staff's 
technical rationale for the proposed standard.\130\ Consistently lower 
emission rates for HC+NOX could result in ``engine credits'' 
for engine families under EPA's

[[Page 83596]]

program for averaging, banking and trading (ABT) of emission credits. 
If manufacturers of engines participate in the ABT program, they could 
partially offset increased manufacturing costs of compliance with the 
proposed CPSC standard, and some of these savings could moderate the 
engine cost increases incurred by generator manufacturers that do not 
make their own engines.
---------------------------------------------------------------------------

    \130\ Tab I of the staff's briefing package.
---------------------------------------------------------------------------

(4.) Testing and Certification
    The proposed rule does not prescribe a particular test that 
manufacturers must use to assess compliance with the performance 
requirements. Instead, the proposed rule includes the test procedure 
and equipment that CPSC would use to assess compliance with the 
applicable performance requirements of the standard.\131\ Manufacturers 
need not use the particular test referenced by the proposed rule, 
although whatever test is used must effectively assess compliance with 
the standard. We have assigned minor costs per unit for this element in 
Table 12, but we welcome comments on this issue.
---------------------------------------------------------------------------

    \131\ i.e., Weighted CO emission rates emitted from the 
generator when operating in normal oxygen: 75 g/h for generators 
with handheld and Class I engines; 150 g/h for generators powered by 
one-cylinder Class II engines; and 300 g/h for generators powered by 
two-cylinder Class II engines.
---------------------------------------------------------------------------

b. Other Potential Costs
    Evaluation of more stringent emission standards by the EPA found 
that pressurized oil lubrication systems for engines would be among the 
engine design changes. EPA's assessment of this engine feature is that 
it results in ``enhanced performance and decreased emissions'' because 
it allows better calibrations and improved cooling potential.\132\ 
Based on estimates made for EPA, variable costs for a pressurized oil 
system would be about $19 for small spark-ignition engines that now 
lack this feature. In the view of the Directorate for Engineering 
Sciences, pressurized lubrication systems would not be necessary to 
comply with the draft standard. We welcome comments on this issue.
---------------------------------------------------------------------------

    \132\ EPA (2006), op. cit.
---------------------------------------------------------------------------

c. Total Costs,per Unit
    Aggregate estimated compliance costs to manufacturers of portable 
generators average approximately $113 per unit for engine and muffler 
modifications necessary to comply with the CO emission requirements of 
the proposed standard. Cost elements by engine class and 
characteristics are shown in Table 12.
[GRAPHIC] [TIFF OMITTED] TP21NO16.016

(1.) Implications for Retail Prices and Consumer Demand
    In addition to the direct costs of the rule, increases in the 
retail price of portable generators (as costs are passed forward to 
consumers) are likely to reduce sales. Additionally, consumers who no 
longer purchase portable generators because of the higher prices will 
experience a loss in utility that is referred to as consumer surplus, 
but is not included in the direct cost estimates described in the last 
section. These impacts are illustrated conceptually in Chart 4 below. 
For purposes of this analysis, we assume that cost increases are pushed 
forward to consumers.
    The downward sloping curve in Chart 4 represents the demand for 
generators; p1 and q1 represent the preregulatory 
price and quantity of generators demanded. After the regulation becomes 
effective, generator prices rise to p2, and

[[Page 83597]]

the quantity of generators demanded declines to q2. The 
value of p2 - p1 represents the direct costs of 
the rule per generator (e.g., $113 for those with Class I engines and 
$138 for two-cylinder Class II generators). The area given by the 
rectangle a represents the aggregate annual direct costs of the rule, 
which is equal to the product of the increase in portable generator 
price (p2 - p1) and the post-regulatory quantity 
demanded (i.e., q2). The triangle b represents additional 
costs of the rule in the form of a loss in consumer surplus: A value 
over and above what consumers paid for the product prior to the 
regulation, but that is lost to the consumers who do not purchase a 
generator at the higher price, p2.
[GRAPHIC] [TIFF OMITTED] TP21NO16.017

    Given information on the pre-regulatory price (p1) and 
quantity demanded (q1), the impact of the rule on product 
prices, and information on the elasticity of demand for portable 
generators (i.e., the percentage change in quantity demanded given a 
percentage change in price), we can make an estimate of the expected 
reduction in sales (q1 - q2), and the lost 
consumer surplus represented by triangle b in Chart 4. Based on 
information presented earlier, estimated preregulatory (current) sales 
(i.e., q1) consist of about 15,000 generators with handheld 
engines; about 801,000 generators with non-handheld Class I engines; 
about 504,000 generators with one-cylinder Class II engines; and about 
65,000 generators with two-cylinder Class II engines. Preregulatory 
retail prices of portable generators (p1) average about $324 
for generators with handheld engines; $534 for generators with non-
handheld Class I engines; $1,009 for generators with one-cylinder Class 
II engines; and $2,550 for generators with two-cylinder Class II 
engines.\133\
---------------------------------------------------------------------------

    \133\ Based on an October 2015 survey of retail prices of more 
than 350 portable generators as reported on Internet sites of six 
retailers.
---------------------------------------------------------------------------

    We are not aware of precise estimates of the price elasticity of 
demand for portable generators; however, the nature of the product 
could argue for a relatively inelastic demand: Sales of the product 
often peak when consumers need or anticipate the need for backup power 
for small and major appliances (e.g., during weather-related outages, 
anticipated Y2K outages). In these circumstances price may not be a 
significant determinant for many purchasing decisions. Based on 
available estimates of the price elasticity of demand for household 
appliances (for example: -0.23, by Houthakker & Taylor,\134\ and -0.35, 
for refrigerators, clothes washers and dishwashers, by Dale & Fujita, 
2008 \135\), the price elasticity for portable generators could be 
approximately -0.3. If this relationship between price increase and 
consumer demand holds true for complying portable generators marketed 
under the proposed rule, a 1.0 percent increase in price for generators 
would result in a 0.3 percent reduction in unit demand.
---------------------------------------------------------------------------

    \134\ Houthakker, H.S. and Taylor, L. (2010). Consumer demand in 
the United States: Analyses and projections, 2nd edition. Cambridge, 
MA: Harvard University Press.
    \135\ Dale, L. and Fugita, K.S. (2008, February). An analysis of 
the price elasticity of demand for household appliances. Energy 
Analysis Department, Environmental Energy Technologies Division, 
Lawrence Berkeley National Laboratory, University of California. 
Berkeley, CA.
---------------------------------------------------------------------------

    Given these parameters, the quantity demanded might decline by 
about 11 percent ($114/$324 x -0.3), on average, for generators with 
handheld engines (reducing sales from about 15,000 to about 13,400 
annually); by an average of about 6 percent ($113/$534 x -0.3) for 
generators with non-handheld Class I engines (projected to reduce sales 
from about 801,000 to about 750,000 annually); by about 3 percent 
($110/$1,009 x -0.3) for generators with one-cylinder Class II engines 
(projected to reduce sales from about 504,000 to about 487,000); and by 
about 1 percent ($138/$2,550 x -0.3) for generators with two-cylinder 
Class II engines

[[Page 83598]]

(projected to reduce sales from about 65,000 to 64,000). As noted in 
our discussion of retail price information, factors other than engine 
capacity or generator power affect retail prices; and lower-priced 
generators with each engine class/category would be expected to face a 
relatively greater price increase under the proposed rule, and 
correspondingly, a greater decrease in consumer demand. In general, we 
would anticipate that generators without features that increase price, 
such as inverter technology, would realize a more significant 
percentage impact on manufacturing costs, retail prices and consumer 
demand, at least initially. Price increases for new generators that 
would comply with the standard could lead more consumers to repair 
their older units or to purchase used units on the secondary market. 
Additionally, price increases for larger portable generators could lead 
more consumers to purchase stationary, standby generators for use 
during power outages.
    The value of lost consumer surplus resulting from increased prices 
under the proposed rule (represented by the area of triangle b in Chart 
4) could be about $4 million annually; comprised of about $90,000 for 
generators with handheld engines; $2.9 million for generators with 
Class I engines; about $910,000 for generators with one-cylinder Class 
II engines; and about $70,000 for generators with two-cylinder Class II 
engines.
(2.) Combined Direct Costs and Lost Consumer Surplus per Unit
    If the estimate of lost consumer surplus is spread over the 
remaining units sold, the estimated costs, per product sold, might 
average about $6.78 for generators with handheld engines ($91,000 / 
13,400 units); $3.85 for generators with Class I engines ($2,889,000 / 
750,000 units); $1.88 for generators with one-cylinder Class II engines 
($914,000 / 487,000 units); and $1.14 for generators with two-cylinder 
Class II engines ($73,000 / 64,000 units). If these per-unit costs of 
lost consumer surplus are combined with the direct manufacturing costs 
estimated previously in this section, the total estimated per-unit 
costs would amount to about $121 for generators with handheld engines; 
$117 for generators with Class I engines; $112 for generators with one-
cylinder Class II engines; and about $139 for generators with two-
cylinder Class II engines. These are the cost figures that will be 
compared to the expected benefits of the rule.
    It is possible, however, that some consumers might perceive greater 
value for complying generators, in terms of fuel efficiency, greater 
ease of starting, product quality and safety. These perceptions could 
moderate the adverse impact on demand (i.e., reduced sales) resulting 
from price increases.
1. Comparison of Benefits and Costs
    Table 13 presents both the estimated benefits (Row 1) and the 
estimated costs (Row 2) of the proposed rule. The expected per-unit 
benefits were derived in Table 5; they average about $243 for 
generators with handheld engines; $254 for generators with Class I 
engines; $214 per unit for generators with one-cylinder Class II 
engines, and; $4 for generators with two-cylinder Class II engines. The 
estimated $4 in benefits for the two-cylinder Class II engines reflects 
the fact that very few consumer deaths have involved these generators 
in the scenarios modeled by NIST and analyzed by CPSC staff, perhaps 
because they are less likely to be brought indoors because of their 
size and weight or loudness during operation. Additionally, given the 
limits on CO emissions for those generators, only about 17 percent of 
the addressable societal costs are projected to be prevented by the 
proposed rule.
    The costs, including both manufacturing compliance costs (from 
Table 12), and the costs associated with lost consumer surplus (from 
the previous section), amount to $121 for generators with handheld 
engines; $117 for generators with Class I engines; $112 for generators 
with one-cylinder Class II engines; and about $139 for generators with 
two-cylinder Class II engines.
    As shown in Row 3, the proposed CO emission standard is estimated 
to result in net benefits (i.e., benefits minus costs) of about $122 
per unit for generators with handheld engines ($243-$121); $137 per 
unit for generators with Class I engines ($254-$117); about $101 for 
generators with one-cylinder Class II engines ($214-$112); and 
approximately -$135 for generators with two-cylinder Class II engines 
($4-$139).
    Projected annual unit sales under the proposed standard are shown 
in Row 4. Finally, Row 5 shows aggregate net benefits based on the 
product of net benefits per unit (Row 3) and product unit sales (Row 
4).
    An examination of Row 5 indicates that aggregate net benefits would 
be maximized at about $153 million annually, if only handheld engines, 
Class I engines, and one-cylinder Class II engines are covered by the 
proposed rule. Including the two-cylinder Class II engines under the 
standard would reduce aggregate net benefits to about $145 million. 
Rather, under the CPSA, the benefits of the rule must bear a reasonable 
relationship to its costs, and the rule must impose the least 
burdensome requirement that prevents or adequately reduces the risk of 
injury. 15 U.S.C. 2058(f)(3)(E) and (F).
    Hence, the preliminary regulatory economic analysis suggests that 
excluding the portable generators with two-cylinder Class II engines 
from the rule would maximize net benefits, an outcome that would be 
consistent with OMB direction but not required under the CPSA. 
Generators with these larger and more powerful engines accounted for 
just 0.4 percent of the 503 consumer CO poisoning deaths addressed by 
the simulation analysis performed by NIST and the benefits analysis 
performed by CPSC staff (Hnatov, Inkster & Buyer, 2016). Portable 
generators with two-cylinder engines are estimated to have comprised 
about 7 percent of units in use over 2004 to 2012 (as shown in Tables 9 
& 10) and about 5 percent of unit sales in recent years (Table 11).

[[Page 83599]]

[GRAPHIC] [TIFF OMITTED] TP21NO16.018

    As discussed previously, the analysis was limited to the 503 out of 
659 CO poisoning deaths during the period 2004 through 2012. Commission 
staff reports that there could be some unquantified benefits associated 
with 156 deaths not modeled by NIST.\136\ However, this would not 
change the main findings of our analysis. If there were some additional 
deaths involving generators with handheld, Class I, or one-cylinder 
Class II engines that would have been prevented, our estimated net 
benefits for these generator classes would increase somewhat. On the 
other hand, even if all of the deaths involving generators with two-
cylinder Class II engines would have been prevented, the costs for this 
class of generators would have exceeded the benefits.
---------------------------------------------------------------------------

    \136\ See Tab K of the staff's briefing package.
---------------------------------------------------------------------------

    Additionally, one underlying assumption for the benefits estimate 
is that there would be no behavioral adaptations by consumers in 
response to the reduced rate of CO emissions from portable generators. 
Knowledge about reduced CO emissions from generators produced under the 
proposed rule could reduce consumers' perceptions of injury likelihood 
and susceptibility, which, in turn, could affect consumer 
behavior.\137\ In economic terms, the proposed rule could reduce what 
we might call the cost or risk-price of unsafe behavior, and implicitly 
provide an incentive for consumers to increase that behavior. If 
consumers are aware of the reduced CO poisoning risk, and the rule does 
not make it more difficult to operate generators indoors, it seems 
likely that there would be some increase in warned-against practices. 
For example, some consumers might reduce the distance between their 
house and the generator because they think closer proximity of the 
generator to the house will reduce the likelihood that the generator 
will be stolen. Similarly, to keep the generator out of the elements, 
some consumers who had run their generator outside might decide to 
bring it into the garage. Additionally, some consumers might even 
decide to run the generator inside their home. Behavioral adaptation as 
a potential effect of the rule is discussed by CPSC's Division of Human 
Factors (HF) (Smith, T., 2016). We cannot quantify this impact, and for 
reasons cited by HF, it could be small. However, while the proposed 
rule will significantly increase the safety of generators from an 
engineering standpoint, it seems likely that the increased technical 
safety predicted by modeling under the assumption of no behavioral 
adaptation will be partially be offset by the behavioral adaptations of 
some users.
---------------------------------------------------------------------------

    \137\ This potential effect of knowledge about improvements in 
safety has been addressed in human factors literature, such as the 
article by Leonard Evans in ``Human Behavior Feedback and Traffic 
Safety,'' published in Human Factors: The Journal of the Human 
Factors and Ergonomics Society, 27(5), 555-576. January 1985.
---------------------------------------------------------------------------

F. Sensitivity Analysis

    The benefit-cost analysis presented above compares benefits and 
costs of our base-case analysis. In this section, we present a 
sensitivity analysis to evaluate the impact of variations in some of 
the important parameters and assumptions used in the base-case 
analysis. Alternative inputs for the sensitivity analysis included:
     Shorter (8 years) and longer (15 years) expected product-
life estimates than the 11 years used in the base analysis;
     A discount rate of 7 percent, rather than 3 percent, to 
express societal costs and benefits in their present value;
     Compliance costs and lost consumer surplus per-unit that 
are 25 percent higher than the base analysis;
     Lower ($5.3 million) and higher ($13.3 million) values of 
a statistical life (VSL) than the $8.7 million value for the base 
analysis; and
     Lower (by 25%) and higher (by 25%) effectiveness for each 
engine class and characteristic at reducing societal costs of CO 
poisoning.
    The results of the sensitivity analysis are presented in Table 14, 
with Part A showing estimated net benefits per unit for generators in 
our base-case analysis (from Table 13) for each engine class and type, 
and Part B presenting the estimated net benefits per unit, using the 
alternative input values.
    Variations in the expected product life had a relatively small 
impact on net benefits; a reduced expected product life decreased 
expected net benefits slightly, while an increased expected product 
life increased net benefits (rows a and b).
    OMB (2003) recommends conducting a regulatory analysis using a 3 
percent and 7 percent discount rate.\138\ Because

[[Page 83600]]

of the relatively long product life of generators, using a 7 percent 
discount rate substantially reduced estimates of net benefits for the 
first three generator categories, but they remained positive (row c). 
However, because benefits were so small for the units with 2-cylinder 
Class II engines, the impact of the 7 percent discount rate on this 
category was negligible.
---------------------------------------------------------------------------

    \138\ Our base analysis discount rate is consistent with 
research suggesting that a real rate of 3 percent is an appropriate 
discount rate for interventions involving public health (see Gold, 
M., Siegel, J., Russell, L. and Weinstein, M., eds. (1996). Cost-
effectiveness in health and medicine. New York: Oxford University 
Press); a 3 percent discount rate (along with a 7 percent discount 
rate) is also recommended for regulatory analyses by the Office of 
Management and Budget (OMB, 2003).
---------------------------------------------------------------------------

    Variations in cost estimates would directly impact our estimates of 
net benefits. Discussions with generator and engine manufacturers 
suggest that the EPA cost estimates, upon which our analysis was based, 
may have led to underestimates of the incremental costs of EFI and 
other components that would be needed for the proposed rule. However, 
the results of this sensitivity analysis show that even if we had 
systematically underestimated the costs of the proposed rule by 50 
percent, the findings of the analysis would have remained unaltered: 
Generators with handheld, Class I, and one-cylinder Class II engines 
would continue to exhibit positive net benefits.
    Finally, we considered the impact of variations in the value of 
statistical life (VSL) on the results of the analysis. Kniesner, 
Viscusi, Wook and Ziliak (2012) suggested that a reasonable range of 
values for VSL was between $4 and $10 million (in 2001 dollars),\139\ 
or about $5.3 million to $13.3 million in 2014 dollars. Consequently, 
we evaluated the sensitivity of our results to variations in the VSL by 
applying these alternative VSLs (rows e and f). This variation had a 
substantial impact on the estimated net benefits (as would be expected 
given deaths account for the great majority of generator-related 
societal costs). Nevertheless, the variations in VSL did not affect the 
results of the analysis.
---------------------------------------------------------------------------

    \139\ Kneiser, Viscusi, Wook & Ziliak (2012). The value of a 
statistical life: Evidence from panel data. The Review of Economics 
and Statistics, 94(1), 74-87.
---------------------------------------------------------------------------

    In summary, for each variation analyzed, the overall estimated net 
benefits of the proposed standard were found to remain positive for the 
first three categories of generators. However, as with the base-case 
analysis, the sensitivity analysis showed that generators with two-
cylinder Class II engines had estimated costs that remained 
substantially greater than the present value of projected benefits.
[GRAPHIC] [TIFF OMITTED] TP21NO16.019


[[Page 83601]]


[GRAPHIC] [TIFF OMITTED] TP21NO16.020

G. Regulatory Alternatives

    In accordance with OMB (2003) guidelines to federal agencies on 
preparation of regulatory impact analyses, the Commission considered 
several regulatory alternatives available to the Commission that could 
address the risks of CO poisoning from consumer use of portable 
generators. The alternatives considered included: (1) Establishing 
less-stringent (higher allowable) CO emission rates; (2) excluding 
generators with Class II, two-cylinder engines from the scope of the 
rule; (3) an option for reducing consumer exposure to CO by using an 
automatic shutoff; (4) establishing later compliance dates; (5) relying 
upon informational measures only; and (6) taking no action.
1. Less Stringent (Higher Allowable) CO Emission Rates
    Cost savings from higher allowable CO emission rates might result 
from lower costs associated with catalysts (if they would not be 
required, or if less costly materials could suffice), less

[[Page 83602]]

extensive engine modifications (other than EFI-related costs) and less 
extensive generator-housing modifications (if housing enlargement and 
other retooling would be minimized). For example, CPSC staff's report 
presenting the technical rationale for the proposed standard speculates 
that 4-stroke handheld engines might not need a catalyst,\140\ and in 
our base-case estimate of catalyst-related costs for generators with 
handheld engines, we assumed an average of 50 percent of the estimated 
costs for units with Class I engines, or about $7 per unit. A less 
stringent emission standard could allow more units with handheld 
engines, and perhaps some with smaller Class I engines, to comply 
without catalytic after-treatment.
---------------------------------------------------------------------------

    \140\ See Tab I of the staff's briefing package.
---------------------------------------------------------------------------

    Expected reductions in societal costs from CO poisoning in 
scenarios analyzed by the Commission could be about 30 percent for 
units with handheld engines; about 36 percent for units with Class I 
engines; about 30 percent for generators with 1-cylinder Class II 
engines; and about 11 percent for generators with 2-cylinder Class II 
engines. We estimate that these reductions in societal costs would be 
reflected in decreased present value of benefits per unit of nearly $90 
for generators with handheld engines (a decrease of 36%); about $70 for 
generators with Class I engines (-28%); and about $40 for units with 1-
cylinder Class II engines (- 18%). It seems likely that cost savings 
from less stringent CO emission requirements would be less than 
expected reductions in benefits. Therefore, net benefits of the rule 
would probably decrease under this regulatory alternative.
    The Commission did not consider a more stringent alternative 
because CPSC engineering staff believes that the rates in the proposed 
rule are based on the lowest rates that are technically feasible. 
Comments providing information on the benefits and costs that would be 
associated with different CO emission rates would be welcome.
2. Alternative Scope: Limiting Coverage to One-Cylinder Engines, 
Exempting Portable Generators With Two-Cylinder, Class II Engines From 
the Proposed Rule
    The Commission could exempt portable generators with two-cylinder 
Class II engines from the requirements of the proposed rule. As shown 
in the base-case analysis, the gross benefits that would be derived 
from including this class of portable generators within the 
requirements of the standard would only amount to about $4 per unit. 
There are two reasons for the small per-unit benefit estimate. First, 
while generators with two-cylinder Class II engines accounted for 7.1 
percent of generators in use during the 2004 through 2012 study period, 
they accounted for only about 1.2 percent of deaths. Consequently, the 
relative risk for generators with two-cylinder Class II engines was 
only about 16 percent of the risk for the handheld and one-cylinder 
models. Second, the analysis of benefits of the proposed emission 
limits for generators with two-cylinder Class II engines (300 g/hr at 
unreduced ambient oxygen levels) suggests that the proposed rule would 
only prevent about 17 percent of the addressable deaths for this class 
of generators (Hnatov, Inkster & Buyer, 2016).\141\
---------------------------------------------------------------------------

    \141\ See Tab K of the staff's briefing package.
---------------------------------------------------------------------------

    The costs of the proposed rule are estimated to amount to $139 per 
two-cylinder, Class II generator, yielding negative net benefits of 
about $135 ($4 in benefits--$139 in costs) per unit. Given annual sales 
of about 64,000 units, the aggregate net benefits associated with this 
class of generators would amount to about -$8.6 million (64,000 
generators x $135 per generator) annually. In other words, excluding 
this class of generators from the requirements of the proposed rule 
would increase the net benefits of the rule by about $8.6 million 
annually, to approximately $153 million. We also note that the total 
estimated value of expected societal costs of CO poisoning deaths and 
injuries per unit, including those not addressed by the staff's 
epidemiological benefits analysis, is $116 per unit (as shown in Tables 
5 & 6); hence, even if all of the deaths attributed to generators with 
two-cylinder Class II engines were to be prevented by the proposed rule 
standard, the costs would exceed the benefits for these generators.
    Exclusion of generators with two-cylinder engines from the scope of 
the rule could create an economic incentive for manufacturers of 
generators with larger one-cylinder engines to either switch to two-
cylinder engines for those models, or if they already have two-cylinder 
models in their product lines, they could be more likely to drop larger 
one-cylinder models from their product lines. The precise impacts of 
such business decisions on aggregate net benefits of the rule are not 
known at this time, but it would likely be of marginal significance. We 
have no evidence that such substitution would occur or, even if it did, 
that the impact would be significant. Moreover, the higher cost of 
manufacturing the two-cylinder generators could offset any cost 
advantage that would result by avoiding the requirements of the 
proposed rule.
    If it would be technologically feasible and cost-effective for 
manufacturers to use smaller two-cylinder engines for generators in 
lower power ratings that are associated with greater per-unit societal 
costs, the reduction in scope of the rule might also specify a minimum 
engine displacement. For example, if this issue were a concern to the 
Commission, it could exempt generators with two-cylinder engines, but 
only if the two-cylinder models had a displacement above a specified 
value of total engine displacement.
    The Commission is including class 2 twin-cylinder generators in the 
scope of the proposed rule and seeks comments and input on whether 
class 2 twin-cylinder generators should be excluded from the scope and 
input on possible shifts in the market of generators powered by two-
cylinder engines, such as those discussed above, that might result if 
two-cylinder generators were excluded from the scope of the rule. The 
Commission seeks comments on what an appropriate limit on displacement 
would be if generators with two-cylinder engines above a certain 
displacement were excluded from the scope, to avoid creating a market 
incentive for small twin-cylinder generators that avoid the scope of 
the proposed rule.
3. Alternate Means of Limiting Consumer Exposure: Automatic Shutoff 
Systems
    CPSC staff considered options for reducing the risk of CO poisoning 
that would require portable generators to shut off automatically if 
they sensed that a potentially hazardous situation was developing, or 
if they were used in locations that are more likely to result in 
elevated COHb levels in users. CPSC engineering staff evaluated four 
shutoff strategies/technologies: (1) A generator-mounted CO-sensing 
system, which would (ideally) sense higher CO levels during operation 
indoors and shut off the engine before dangerous levels build up; (2) a 
CO-sensing system located away from the generator (e.g., inside the 
dwelling) that relies on the user to properly place the sensing unit in 
a location where it can communicate with the generator and send a 
signal remotely, causing the engine to shut down; (3) a generator-
mounted global-positioning (GPS) system intended to infer operation of 
the generator indoors (from detection of reduced satellite signal 
strength) and automatically shut down the engine; and (4) applicable to 
generators equipped with EFI, an

[[Page 83603]]

algorithm programmed into the engine control unit (ECU) that relies on 
system sensors to infer indoor operation, signaling the ECU to shut 
down the engine. The findings of the CPSC engineering evaluation 
reports on each of the shutoff strategies are summarized in detail in 
the briefing memorandum for the proposed rule.
    As alternative means of limiting exposure to CO, automatic shutoff 
systems could be incorporated into a standard that limits CO production 
per hour (such as the draft proposed standard), or they could enable 
compliance with an alternative standard that requires generators to 
shut off automatically if they are used in conditions that could lead 
to accumulation of hazardous levels of CO. Allowing the use of 
automatic shutoff systems, as either a supplement to limits on CO 
production per hour or under an alternative shutoff standard could 
potentially be less costly for manufacturers, and result in greater 
reductions in CO poisoning for consumers.
    However, CPSC staff does not believe that an automatic shutoff 
standard or option is sufficiently proven to be feasible at this time. 
As noted, CPSC engineering staff investigated four different approaches 
for an automatic shutoff system, and was not able to demonstrate how 
any of the shutoff systems could be implemented satisfactorily. 
Unresolved concerns with the automatic shutoff technologies studied by 
CPSC staff include: (1) Possibly creating a false sense of safety, 
which could lead to increased use of portable generators indoors; (2) 
alternatives that require CO sensors falsely could identify hazards, 
which would detrimentally affect the utility of the generator when used 
in proper locations, and could lead to consumers overriding the 
mechanism; (3) the system would have to be shown to be durable and 
capable of functioning after being stored for long periods and being 
used under widely different conditions; and (4) use of algorithms to 
shut off engines with ECUs would have to be engine-specific and 
tailored to each engine function, requiring a significant amount of 
additional testing on this system. These concerns would have to be 
resolved before a standard incorporating an automatic shutoff option 
could be developed.
4. Different (Longer) Compliance Dates
    As noted in the technical rationale for the proposed rule, staff 
believes that 1 year is sufficient lead time for manufacturers to 
implement the necessary modifications on both one-cylinder and two-
cylinder Class II engines powering generators.\142\ This assessment is 
partly based on greater industry experience in manufacturing small 
engines with closed-loop EFI for a variety of applications, including 
portable generators, since 2006, when the EPA estimated that 
manufacturers would need 3 years to 5 years to implement closed-loop 
EFI and make necessary engine improvements, if EPA were to adopt more 
stringent requirements for its HC+NOX emission standard for 
small SI engines. Because of the experience gained by engine 
manufacturers in recent years, the Commission thinks 1 year from the 
date of publication of the final rule would provide an appropriate 
lead-time for generators powered by Class II engines. The Commission is 
proposing a later compliance date that would take effect 3 years from 
the date of publication of the final rule for generators powered by 
smaller engines (handheld and Class I engines). This longer period 
addresses manufacturers' concerns that there may be different 
challenges associated with accommodating the necessary emission control 
technologies on these smaller engines (even though industry has also 
gained some limited experience with incorporating fuel-injection on 
handheld and Class I engines).
---------------------------------------------------------------------------

    \142\ Briefing memorandum for staff's briefing package.
---------------------------------------------------------------------------

    The Commission could decide that the recent industry experience in 
manufacturing small engines with EFI, cited in the staff's technical 
rationale (Buyer, 2016), while facilitating compliance for some 
manufacturers of engines and generators, might not shorten the time 
needed by other manufacturers that have not gained relevant experience 
in application of EFI technology to their products. Based on recent 
discussions with generator manufacturers, a longer time frame before 
compliance is required would allow firms more time to design and build 
parts in-house, which could be more cost-effective than outsourcing. 
Lack of relevant recent experience with incorporating EFI in engine 
manufacturing could be more common for small manufacturers of 
generators. As noted in the staff's initial regulatory flexibility 
analysis, a longer period before the rule becomes effective (or before 
compliance is required for generators with smaller engines) would 
provide small engine manufacturers more time to develop engines that 
would meet the requirements of the proposed rule, and in the case of 
small manufacturers of generators that do not also manufacture their 
own engines, ``it would provide them with additional time to find a 
supplier for compliant engines so that their production of generators 
would not be interrupted [and . . . ] for small importers, a later 
effective date would provide them with additional time to locate a 
supplier of compliant generators.'' \143\
---------------------------------------------------------------------------

    \143\ Tab M of the staff's briefing package.
---------------------------------------------------------------------------

5. Informational Measures
    OMB (2003) notes that informational measures often will be 
preferable when agencies are considering regulatory action to address a 
market failure arising from inadequate information. As discussed 
previously, although labels for generators were improved in 2007, with 
the introduction of mandatory labels, deaths and injuries from the 
improper placement of newly purchased generators suggest that at least 
some consumers poorly understand and process the information contained 
in the operating instructions and warning labels and consequently, 
these consumers continue to put themselves and others at risk through 
the improper placement of generators in enclosed areas. Additionally, a 
review of injury and market data since improved warning labels have 
been required finds that there is not sufficient evidence to conclude 
that the label required in the current labeling standard has reduced 
the CO fatality risks associated with portable generators. Moreover, 
findings of other general studies on the effectiveness of labels ``make 
it seem unlikely that any major reductions in fatalities should be 
anticipated due to the introduction of these labels.'' \144\
---------------------------------------------------------------------------

    \144\ Tab H of the staff's briefing package.
---------------------------------------------------------------------------

    Other informational measures that the Commission could take include 
increased provision of information through means such as government 
publications, telephone hotlines, or public interest broadcast 
announcements. CPSC has previously taken actions to alert consumers to 
the dangers of CO poisoning by portable generators, and the Commission 
believes that continued involvement in these activities is warranted. 
However, evidence of problems in processing information, and continued 
occurrence of deaths and injuries from improper use of portable 
generators, indicate that informational measures do not adequately 
address the risks presented by these products.
6. Taking No Action To Establish a Mandatory Standard
    The Commission could take no further regulatory action to establish 
a mandatory standard on portable

[[Page 83604]]

generators. Given that some generator manufacturers have demonstrated 
that it is technologically feasible to produce generators that emit 
significantly lower levels of CO, taking no regulatory action to 
establish a mandatory standard would allow manufacturers to market low 
CO-emitting generators if they believe that there would be a market for 
such products. In addition, it would allow fully informed consumers to 
purchase low CO-emitting generators if they value the reduced risk. 
However, the Commission does not expect that a significant number of 
generators with CO emission rates proposed by the standard would be 
marketed voluntarily, at least in the short run.

H. Conclusions From Preliminary Regulatory Analysis

    During 2004 to 2012, there was an average of about 73 portable 
generator-related deaths and at least 2,800 generator-related nonfatal 
injuries annually. The societal costs of these injuries, as described 
above, totaled about $820 million annually. During the same period, 
there was an average of about 11.1 million portable generators in use, 
suggesting about 0.66 deaths and at least 25.2 nonfatal CO poisonings 
per 100,000 portable generators in use. Based on indoor air quality 
modeling by NIST, and a staff technical evaluation of the predicted 
health effects for scenarios and housing characteristics found in the 
CPSC incident data, CPSC estimated that the proposed rule would prevent 
about one-third of these deaths and injuries.\145\
---------------------------------------------------------------------------

    \145\ See Tab K of the staff's briefing package.
---------------------------------------------------------------------------

    The preliminary regulatory analysis evaluated the benefits and 
costs of the proposed rule. It distinguished between four categories of 
portable generators by engine class and type: (1) Those with handheld 
engines with displacement of 80 cc or less; (2) generators with Class I 
engines with engine displacement of less than 225 cc; (3) generators 
with one-cylinder Class II engines with engine displacement of 225 cc 
or more; and (4) two-cylinder class II generators with engine 
displacement of 225 cc or more.
    Generators with Class I and one-cylinder Class II engines accounted 
for about 92.2 percent of portable generators in use over the period 
2004 through 2012. Generators with handheld engines (with engine 
displacement of 80 cc or less) and two-cylinder Class II engines (with 
displacement of 225 cc or more) accounted for 0.7 percent and 7.1 
percent of portable generators in use, respectively, over 2004-2012.
    The preliminary regulatory analysis suggests that the proposed rule 
could have substantial benefits for most generators. The estimated 
gross benefits per generator (over its expected product life) ranged 
from about $215 to $255 for models with hand-held, Class I, and one-
cylinder Class II engines. However, gross benefits for the units with 
two-cylinder Class II engines amounted to only about $4 per unit.
    The estimated costs of the proposed rule were generally similar 
across generator types, ranging from about $110 to $120 per generator 
for the models with handheld, Class I, and one-cylinder Class II 
engines, to about $140 for the models with two-cylinder Class I 
engines. The retail price increases likely to result from these higher 
costs could reduce portable generator sales by roughly 50,000 units 
annually, an overall sales reduction of about 3 to 4 percent. The 
relative impact on handheld generator sales could be greater because of 
the lower base price of these models.
    Given these benefit and cost estimates, net benefits (i.e., 
benefits minus costs) ranged from about $100 to about $140 per 
generator for the models with handheld, Class I, and one-cylinder Class 
II engines. However, net benefits were a negative $135 for the models 
with two-cylinder Class II engines (i.e., benefits of $4 per generator 
minus costs of $139 per generator). Consequently, net benefits for 
portable generators as a group would be maximized by excluding the 
models with two-cylinder Class II engines from the rule.
    Estimated net benefits can be converted to aggregate annual 
estimates, given estimates of the annual sales of portable generators. 
The estimated aggregate net benefits, based on 1 year's sales of the 
generators with handheld, Class I, and one-cylinder Class II engines 
amounted to $153 million. Including the models with two-cylinder Class 
II engines (which account for only about 5 percent of portable 
generators sold in recent years) under the requirements of the standard 
would reduce aggregate net benefits to about $145 million annually.
    The sensitivity analysis supported the findings of the base 
analysis. None of the inputs used in the sensitivity analysis altered 
the main findings that there would be positive net benefits for the 
generators with handheld, Class I, and one-cylinder Class II engines, 
but negative net benefits for the generators with two-cylinder Class II 
engines.
    Additionally, we note that benefits of the proposed rule were 
estimated based on an assumption that consumer behavior would not 
change in response to knowledge of the reductions in CO emissions from 
generators. However, a perceived reduction in the risk associated with 
using the generators in unsafe environments may increase the likelihood 
that some consumers will use their generators in the house, in the 
garage, or in outside locations that are near openings to the house--
behaviors the CPSC recommends against. Although such a response could 
offset the expected benefits from the proposed rule, staff anticipates 
that any impact would be minimal. On the other hand, the benefits 
estimates were based on 503 of the 659 CO-related deaths during 2004 
through 2012. These were the deaths occurring in fixed-residential or 
similar structures (e.g., detached and attached houses, and fixed 
mobile homes) that could be modeled by NIST. CPSC staff believes that 
some unquantified proportion of the remaining 156 deaths that were not 
modeled by NIST, because they occurred at non-fixed home locations 
(e.g., temporary structures such as trailers, horse trailers, 
recreational vehicles, or tents), and some that occurred when portable 
carbureted generators were operated outdoors, would have been 
prevented.\146\ If so, the benefits estimates would have been somewhat 
higher than presented in this analysis.
---------------------------------------------------------------------------

    \146\ Tab K of the staff's briefing package.
---------------------------------------------------------------------------

XI. Initial Regulatory Flexibility Analysis

    This section provides an analysis of the impact on small businesses 
of a proposed rule that would establish a mandatory safety standard for 
portable generators. Whenever an agency is required to publish a 
proposed rule, section 603 of the Regulatory Flexibility Act (5 U.S.C. 
601-612) requires that the agency prepare an initial regulatory 
flexibility analysis (IRFA) that describes the impact that the rule 
would have on small businesses and other entities. An IRFA is not 
required if the head of an agency certifies that the proposed rule will 
not have a significant economic impact on a substantial number of small 
entities. 5 U.S.C. 605. The IRFA must contain:
    (1) A description of why action by the agency is being considered;
    (2) a succinct statement of the objectives of, and legal basis for, 
the proposed rule;
    (3) a description of and, where feasible, an estimate of the number 
of small entities to which the proposed rule will apply;

[[Page 83605]]

    (4) a description of the projected reporting, recordkeeping and 
other compliance requirements of the proposed rule, including an 
estimate of the classes of small entities which will be subject to the 
requirement and the type of professional skills necessary for 
preparation of the report or record; and
    (5) identification to the extent practicable, of all relevant 
Federal rules which may duplicate, overlap or conflict with the 
proposed rule.
    An IRFA must also contain a description of any significant 
alternatives that would accomplish the stated objectives of the 
applicable statutes and that would minimize any significant economic 
impact of the proposed rule on small entities. Alternatives could 
include: (1) Establishment of differing compliance or reporting 
requirements that take into account the resources available to small 
businesses; (2) clarification, consolidation, or simplification of 
compliance and reporting requirements for small entities; (3) use of 
performance rather than design standards; and (4) an exemption from 
coverage of the rule, or any part of the rule thereof, for small 
entities.

A. Reason for Agency Action

    The proposed rule would limit the rate of CO emitted by portable 
generators and is intended to reduce the risk of death or injury 
resulting from the use of a portable generator in or near an enclosed 
space. The Directorate for Epidemiology, Division of Hazard Analysis 
(EPHA) reports that there were 659 deaths involving portable generators 
from 2004 to 2012, an average of about 73 annually.\147\ Furthermore, 
there was a minimum of 8,703 nonfatal CO poisonings involving portable 
generators that were treated in hospital emergency departments from 
2004 through 2012, or a minimum of about 967 annually (Hanway, 2015); 
and, as discussed in the preliminary regulatory analysis, there were an 
additional 16,600 medically attended injuries treated in other 
settings, or an estimated 1,851 per year. The societal costs of both 
fatal and nonfatal CO poisoning injuries involving portable generators 
amounted to about $821 million ($637 million for fatal injuries + $184 
million for nonfatal injuries) on an annual basis. The proposed 
standard is expected to significantly reduce generator-related injuries 
and deaths and the associated societal costs.
---------------------------------------------------------------------------

    \147\ Tab A of the staff's briefing package.
---------------------------------------------------------------------------

B. Objectives of and Legal Basis for the Rule

    The objective of the proposed rule is to reduce deaths and injuries 
resulting from exposure to CO associated with portable electric 
generators being used in or near confined spaces. The Commission 
published an ANPR in December 2006, which initiated this proceeding to 
evaluate regulatory options and potentially develop a mandatory 
standard to address the risks of CO poisoning associated with the use 
of portable generators. The proposed rule is being promulgated under 
the authority of the Consumer Product Safety Act (CPSA).

C. Small Entities to Which the Rule Will Apply

    The proposed rule would apply to small entities that manufacture or 
import SI portable generators. Based on data collected by Power Systems 
Research, Trade IQ, and general market research, the Commission has 
identified more than 70 manufacturers of generators that have at some 
time supplied portable generators to the U.S. market. However, most of 
these manufacturers were based in other countries. The Commission has 
identified 20 domestic manufacturers of gasoline-powered portable 
generators, of which 13 would be considered small based on the Small 
Business Administration (SBA) size guidelines for North American 
Industry Classification System (NAICS) category 335312 (Motor and 
Generator Manufacturing), which categorizes manufacturers as small if 
they have fewer than 1,250 employees. Four of the small manufacturers 
are engaged primarily in the manufacture or supply of larger, 
commercial, industrial, or backup generators, or other products, such 
as electric motors, which would not be subject to the draft standard. 
For the other nine small manufacturers, portable generators could 
account for a significant portion of the firms' total sales. Of these 
nine small, domestic manufacturers, six have fewer than 99 employees; 
one has between 100 and 199 employees; another firm has between 200 and 
299 employees; and one has between 300 and 399 employees, based on firm 
size data from Hoovers, Inc., and interviews with several 
manufacturers.
    In some cases, a small manufacturer may be responsible for 
designing its own brand of generators but outsource the actual 
production of the generators to other manufacturers, which are often 
based in China. Other small manufacturers may assemble using components 
(including engines) purchased from other suppliers. There may be some 
small manufacturers that manufacture or fabricate some components of 
the generators, in addition to assembling them.
    Using the same sources of data described above, the Commission 
identified more than 50 firms that have imported gasoline-powered 
portable generators. However, in some cases, the firms have not 
imported generators regularly, and generators appear to account for an 
insignificant portion of these firm's sales. Of these firms, the 
Commission believes that 20 may be small importers of gasoline-powered 
portable generators that could be affected by the proposed rule. 
Importers were considered to be a small business if they had fewer than 
200 employees, based on the SBA guidelines for NAICS category 423610 
(Electrical Apparatus and Equipment, Wiring Supplies, and Related 
Equipment Merchant Wholesalers) or $11.0 million in average annual 
receipts, based on the SBA guidelines for NAICS category 443141 
(Household Appliance Stores). Of the 20 small, potential importers 
staff identified, all have 50 or fewer employees, based on firm size 
data from Hoovers, Inc.

D. Compliance, Reporting, and Record Keeping Requirements of Proposed 
Rule

    The proposed rule would establish a performance standard that would 
limit the rate of CO that could be produced by portable generators that 
are typically used by consumers for electrical power in emergencies or 
other circumstances in which the electrical power has been shut off or 
is not available. The performance standard would be based on the 
generator's weighted CO emissions rate, and stated in terms of grams/
hour (g/hr), depending upon the class \148\ of the engine powering the 
generator. Generators powered by handheld engines and Class I engines 
would be required to emit CO at a

[[Page 83606]]

weighted rate that is no more than 75 grams per hour (g/hr). Generators 
powered by Class II engines with a single cylinder would be required to 
emit CO at a weighted rate that is no more than 150 g/hr. Generators 
powered by Class II engines with two (or twin) cylinders, which are 
generally larger than others in the class, and are believed to comprise 
a very small share of the consumer market, would be required to emit CO 
at a weighted rate of no more than 300 g/hr.
---------------------------------------------------------------------------

    \148\ Because most of the generators that were associated with 
fatal CO poisoning incidents reported to CPSC were gasoline-fueled, 
staff has chosen to set the performance standard based on the U.S. 
Environmental Protection Agency's (EPA) classification of the small 
SI engine powering the generator and the number of cylinders the 
engine has. The EPA broadly categorizes small SI engines as either 
non-handheld or handheld, and within each of those categories, 
further distinguishes them into different classes, which are based 
upon engine displacement. Nonhandheld engines are divided into Class 
I and Class II, with Class I engines having displacement above 80 cc 
up to 225 cc and Class II having displacement at or above 225 cc but 
maximum power of 19 kilowatts (kW). Handheld engines, which are 
divided into Classes III, IV, and V, are all at or below 80 cc. 
Staff chose to divide non-handheld Class II engines based on whether 
the engine had a single cylinder or twin cylinders.
---------------------------------------------------------------------------

    Section 14 of the CPSA requires that manufacturers, importers, or 
private labelers of a consumer product subject to a consumer product 
safety rule to certify, based on a test of each product or a reasonable 
testing program that the product complies with all rules, bans or 
standards applicable to the product. The proposed rule details the test 
procedure that the Commission would use to determine compliance with 
the standard, but also provides that any test procedure may be used 
that will accurately determine the emission level of the portable 
generator. However, for certification purposes, manufacturers must 
certify that the product conforms to the standard, based on either a 
test of each product, or any reasonable alternative method to 
demonstrate compliance with the requirements of the standard. For 
products that manufacturers certify, manufacturers would issue a 
general certificate of conformity (GCC).
    The requirements for GCCs are in Section 14 of the CPSA. Among 
other requirements, each certificate must identify the manufacturer or 
private labeler issuing the certificate and any third party conformity 
assessment body, on whose testing the certificate depends, the place of 
manufacture, the date and place where the product was tested, each 
party's name, full mailing address, telephone number, and contact 
information for the individual responsible for maintaining records of 
test results. The certificates must be in English. The certificates 
must be furnished to each distributor or retailer of the product and to 
the CPSC, if requested.
1. Costs of Proposed Rule That Would Be Incurred by Small Manufacturers
    The most likely method for manufacturers of portable generators to 
comply with the proposed CO emissions requirement is converting to the 
use of closed-loop electronic fuel-injection (EFI) systems instead of 
conventional carburetors, to control the delivery of gasoline to the 
pistons of generator engines. Manufacturers also are likely to use 
catalytic converters in the mufflers of the generator engines. As 
discussed in the preliminary regulatory analysis in Section X, the cost 
to manufacturers for complying with the proposed rule is expected to 
be, on average, about $114 per unit for generators with handheld 
engines (1.1% of unit sales between 2010 and 2014), $113 per unit for 
generators with Class I engines (57.8% of unit sales between 2010 and 
2014); $110 for those with single cylinder Class II engines (36.4% of 
unit sales between 2010 and 2014); and $138 for those with twin 
cylinder Class II engines (4.7% of unit sales between 2010 and 2014).
    These estimates include the variable costs related to EFI, 
including an oxygen sensor for a closed-loop system, a battery and 
alternator or regulator; and 3-way catalysts. The estimates also 
include the fixed costs associated with the research and development 
required to redesign the generators, tooling costs, and the costs 
associated with testing and certification that the redesigned engines 
comply with the EPA requirements for exhaust constituents they 
regulate, HC+NOX and CO emissions.\149\
---------------------------------------------------------------------------

    \149\ The modifications to small SI engines to comply with the 
CO emission requirements would likely require engine manufacturers 
to seek certifications (as new engine families) under EPA 
requirements for HC+NOX and CO, with the attendant costs 
for fees and testing, which could be passed on to generator 
manufacturers that purchase the engines to power their products. 
Some of the larger manufacturers of portable generators are 
vertically-integrated firms that also manufacture the engines that 
power their products. These testing and certification requirements 
are to meet EPA requirements and are in addition to the testing and 
certification requirements of Section 14 of the CPSA.
---------------------------------------------------------------------------

    Manufacturers likely would incur some additional costs to certify 
that their portable generators meet the requirements of the proposed 
rule, as required by Section 14 of the CPSA. The certification must be 
based on a test of each product or a reasonable testing program. 
Manufacturers may use any testing method that they believe is 
reasonable and are not required to use the same test method that would 
be used by CPSC to test for compliance. Based on information from a 
testing laboratory, the cost of the testing might be more than $6,000 
per generator model, although it may be possible to use the results 
from other tests that manufacturers already may be conducting, such as 
testing to ensure that the engines comply with EPA requirements, per 40 
CFR part 1054, for HC+NOX and CO emissions to certify that 
the generator meets the requirements of the proposed rule. 
Manufacturers and importers also may rely upon testing completed by 
other parties, such as their foreign suppliers, in the case of 
importers, or the engine suppliers in the case of manufacturers, if 
those tests provide sufficient information for the manufacturers or 
importers to certify that the generators comply with the proposed rule.
    The Commission welcomes comments from the public regarding the cost 
or other impacts of the certification requirements under Section 14 of 
the CPSA and whether it would be feasible to use the results of tests 
conducted for certifying compliance with EPA requirements to certify 
compliance with the proposed rule.
2. Impacts on Small Businesses
Manufacturers
    To comply with the proposed rule, small manufacturers would incur 
the costs described above to redesign and manufacture generators that 
comply with the CO emissions requirements and to certify that they 
comply. However, to the extent that the volume of generators produced 
by small manufacturers is lower than that of the larger manufacturers, 
the costs incurred by smaller manufacturers may be higher than the 
average costs reported above. One reason to expect that costs for 
lower-volume manufacturers could be higher than average is that some of 
the costs are fixed. For example, research and development costs were 
estimated to be about $203,000, on average, for Class II engines and 
about $316,000 for Class I engines. On a per-unit basis, the 
preliminary regulatory analysis estimated that these costs would 
average about $4 for Class I engines and $3 for Class II engines, but 
for manufacturers with a production volume only one-half the average 
production volume, the per-unit costs would be twice the average.
    For lower-volume producers, the per-unit costs of the components 
necessary to modify their engines might also be higher than those for 
higher-volume producers. As discussed in the preliminary regulatory 
analysis, generators that meet the requirements of the proposed rule 
would probably use closed-loop electronic fuel-injection instead of 
conventional carburetors. Therefore, manufacturers would incur the 
costs of adding components associated with EFI to the generator, 
including injectors, pressure regulators, sensors, fuel pumps, and 
batteries. Based on information obtained from a generator manufacturer, 
the cost of these components might be as much as 35 percent higher for 
a manufacturer that purchased only a few thousand units at a time, as 
opposed to more than 100,000 units.

[[Page 83607]]

    While the cost for small, low-volume manufacturers that manufacture 
their own engines might be higher than for high-volume manufacturers, 
small portable generator manufacturers often do not manufacture the 
engines used in their generators, but obtain them from engine 
manufacturers such as Honda, Briggs and Stratton, and Kohler, as well 
as several engine manufacturers based in China. These engine 
manufacturers often supply the same engines to other generator or 
engine-driven tool manufacturers. Because these engine manufacturers 
would be expected to have higher production volumes and can spread the 
fixed research and development and tooling costs over a higher volume 
of production, the potential disproportionate impact on lower-volume 
generator producers might be mitigated to some extent.
    As discussed in the preliminary regulatory analysis, the retail 
prices CPSC observed for portable generators from manufacturers and 
importers of all sizes ranged from a low of $133 to $4,399, depending 
upon the characteristics of the generator. On a per-unit basis, the 
proposed rule is expected to increase the costs of generators by an 
average of $110 to $140. Generally, impacts that exceed 1 percent of a 
firm's revenue are considered to be potentially significant. Because 
the estimated average cost per generator would be between about 3 
percent and 80 percent of the retail prices (or average revenue) of 
generators, the proposed rule could have a significant impact on 
manufacturers and importers that receive a significant portion of their 
revenue from the sale of portable generators.
    Based on a conversation with a small manufacturer, CPSC staff 
believes that the proposed rule may have a disproportionate impact on 
generator manufacturers that compete largely on the basis of price, 
rather than brand name or reputation. Currently, CPSC cannot identify 
how many of the nine domestic small manufacturers of engines compete on 
the basis of price. One reason for the disproportionate impact is that 
consumers of the lower priced generators are probably more price 
sensitive than consumers of the brand name generators and may be more 
likely to reduce or delay their purchases of generators in response to 
the cost increases that would be expected to result from the proposed 
rule. A second reason that manufacturers that compete largely on the 
basis of price could be disproportionately impacted is that brand name 
generator manufacturers might have more options for absorbing the cost 
increases that result from the proposed rule. For example a high-end 
generator manufacturer might be able to substitute a less expensive, 
but still adequate engine for a name brand engine that they currently 
might be using. On the other hand, manufacturers that have been 
competing primarily on the basis of price are more likely to have 
already made such substitutions and will have fewer options for 
absorbing any cost increases. As a result, the price differential 
between generators aimed at the low-end or price-conscious market 
segments and the name brand generators will be reduced, which could 
affect the ability of the manufacturers of generators aimed at the 
price conscious market to compete with the name-brand manufacturers.
Importers
    For many small importers, the impact of the proposed rule would be 
expected to be similar to the impact on small manufacturers. One would 
expect that the foreign suppliers would pass much of the costs of 
redesigning and manufacturing portable generators that comply with the 
proposed rule to their domestic distributors. Therefore, the cost 
increases experienced by small importers would be similar to those 
experienced by small manufacturers. As with small manufacturers, the 
impact of the proposed rule might be greater for those importers that 
primarily compete on the basis of price. Currently, CPSC cannot 
identify how many of the 20 domestic, small importers of engines 
compete on the basis of price.
    In some cases, the foreign suppliers might opt to withdraw from the 
U.S. market, rather than incur the costs of redesigning their 
generators to comply with the proposed rule. If this occurs, the 
domestic importers would have to find other suppliers of portable 
generators or exit the portable generator market. Exiting the portable 
generator market could be considered a significant impact, if portable 
generators accounted for a significant percentage of the firm's 
revenue.
    Small importers will be responsible for issuing a GCC certifying 
that their portable generators comply with the proposed rule should it 
become final. However, importers may rely upon testing performed and 
GCCs issued by their suppliers in complying with this requirement.

E. Federal Rules That May Duplicate, Overlap, or Conflict With the 
Proposed Rule

    The Commission has not identified any federal rules that duplicate 
or conflict with the proposed rule. The EPA promulgated a standard in 
2008 for small spark-ignited engines that set a maximum rate for CO 
emissions. However, the maximum level set by the EPA is higher than the 
proposed CPSC standard for portable generators.

F. Alternatives Considered To Reduce the Burden on Small Entities

    Under section 603(c) of the Regulatory Flexibility Act, an initial 
regulatory flexibility analysis should ``contain a description of any 
significant alternatives to the proposed rule which accomplish the 
stated objectives of the applicable statutes and which minimize any 
significant impact of the proposed rule on small entities.'' CPSC 
examined several alternatives to the proposed rule that could reduce 
the impact on small entities. These include: (1) Less stringent CO 
emission rates; (2) limit coverage to one-cylinder engines; (3) an 
option for reducing consumer exposure to CO by using an automatic 
shutoff; (4) establishing alternative compliance dates; (5) 
informational measures; or (6) taking no action. These alternatives are 
discussed in more detail in Section X.G.

G. Summary and Request for Comments Regarding Potential Impact on Small 
Business

    The Commission has identified about nine small generator 
manufacturers and about 20 small generator importers that would be 
impacted by the proposed rule.
    The most likely means of complying with the proposed rule would be 
to use closed-loop electronic fuel-injection (EFI) systems, instead of 
conventional carburetors, to control the delivery of gasoline to the 
pistons of generator engines and to use catalytic converters in the 
mufflers of the generator engines to be able to meet the EPA's 
HC+NOX emission standards. The Commission estimates that, on 
average, the requirements will increase the costs of generator 
manufacturers by about $110 and $140, depending upon engine type. The 
costs might be higher than average for lower-volume manufacturers.
    Manufacturers and suppliers that serve the low-end of the market 
and compete mostly on the basis of price might be more severely 
impacted by the proposed rule because their customers may be more price 
sensitive; and compared with larger manufacturers, they may not have 
the same options of reducing other costs to mitigate the impact of the 
proposed rule on the price of generators. Suppliers of name-brand 
generators or ones that compete on basis other than price might be able 
to make other adjustments, such as using less expensive engines to 
mitigate the

[[Page 83608]]

impact of the proposed rule on the price of their generators. CPSC 
currently cannot identify how many of the nine domestic, small 
manufacturers or the 20 domestic, small importers of engines compete on 
the basis of price.
    Generator manufacturers and importers will be responsible for 
certifying that their products comply with the requirements of the 
proposed rule. Testing and certification costs can have a 
disproportionate impact on small manufacturers, depending upon the cost 
of the tests and volume of production, relative to larger 
manufacturers. However, some of these testing costs might be mitigated, 
if manufacturers could use the results of testing already being 
conducted (such as, for example, testing to certify compliance with EPA 
requirements), to offset some of the testing costs required for 
certification with the proposed rule.
    The Commission invites comments on this IRFA and the potential 
impact of the proposed rule on small entities, especially small 
businesses. Small businesses that believe they will be affected by the 
proposed rule are especially encouraged to submit comments. The 
comments should be specific and describe the potential impact, 
magnitude, and alternatives that could reduce the impact of the 
proposed rule on small businesses.
    In particular, the Commission seeks comment on:
     The types and magnitude of manufacturing costs that might 
disproportionately impact small businesses or that were not considered 
in this analysis;
     the costs of the testing and certification requirements of 
the proposed rule, including whether EPA testing can be used to meet 
the certification requirements for the proposed rule;
     whether other factors not considered in this analysis 
could be significant, such as EPA's Averaging, Banking and Trading 
(ABT) program that could allow manufacturers of engine families that do 
have low CO emissions to meet the proposed rule and that also have very 
low HC+NOX emissions to ``buy credits'' in the ABT program, 
thus allowing their other engine families to exceed HC+NOX 
limits;
     differential impacts of the proposed rule on small 
manufacturers or suppliers that compete in different segments of the 
portable generator market; and finally,
     CPSC would be interested in any comments that provide 
alternatives that would minimize the impact on small businesses but 
would still reduce the risk of CO poisoning associated with generators.

XII. Environmental Considerations

    The Commission's regulations address whether CPSC is required to 
prepare an environmental assessment (EA) or an environmental impact 
statement (EIS). 16 CFR 1021.5. Those regulations state CPSC's actions 
that ordinarily have ``little or no potential for affecting the human 
environment,'' and therefore, are categorically excluded from the need 
to prepare an EA or EIS. Among those actions are rules, such as the 
portable generator NPR, which provide performance standards for 
products. Id. 1021.5(c)(1).

XIII. Executive Order 12988 (Preemption)

    In accordance with Executive Order 12988 (February 5, 1996), the 
CPSC states the preemptive effect of the proposed rule, as follows:
    The regulation for portable generators is proposed under authority 
of the CPSA. 15 U.S.C. 2051-2089. Section 26 of the CPSA provides: 
``whenever a consumer product safety standard under this Act is in 
effect and applies to a risk of injury associated with a consumer 
product, no State or political subdivision of a State shall have any 
authority either to establish or to continue in effect any provision of 
a safety standard or regulation which prescribes any requirements as to 
the performance, composition, contents, design, finish, construction, 
packaging or labeling of such product which are designed to deal with 
the same risk of injury associated with such consumer product, unless 
such requirements are identical to the requirements of the Federal 
Standard''. 15 U.S.C. 2075(a). Upon application to the Commission, a 
state or local standard may be excepted from this preemptive effect if 
the state or local standard: (1) Provides a higher degree of protection 
from the risk of injury or illness than the CPSA standard, and (2) does 
not unduly burden interstate commerce. In addition, the federal 
government, or a state or local government, may establish or continue 
in effect a non-identical requirement for its own use that is designed 
to protect against the same risk of injury as the CPSC standard if the 
federal, state, or local requirement provides a higher degree of 
protection than the CPSA requirement. 15 U.S.C. 2075(b).
    Thus, the portable generator requirements proposed in this Federal 
Register would (if finalized) preempt non-identical state or local 
requirements for portable generators designed to protect against the 
same risk of injury and prescribing requirements regarding the 
performance, composition, contents, design, finish, construction, 
packaging or labeling of portable generators.

XIV. Certification

    Section 14(a) of the CPSA requires that products subject to a 
consumer product safety rule under the CPSA, or to a similar rule, ban, 
standard or regulation under any other act enforced by the Commission, 
must be certified as complying with all applicable CPSC-enforced 
requirements. 15 U.S.C. 2063(a). A final rule on portable generators 
would subject portable generators to this certification requirement.

XV. Effective Date

    The CPSA requires that consumer product safety rules take effect 
not later than 180 days from their promulgation unless the Commission 
finds there is good cause for a later date. 15 U.S.C. 2058(g)(1). The 
Commission proposes that the rule would take effect 1 year from the 
date of publication of the final rule for generators powered by Class 
II engines and three years from the date of publication of the final 
rule for generators powered by handheld and Class I engines.
    Because of the experience gained by engine manufacturers in recent 
years in designing and building EFI small SI engines, the Commission 
believes one year from the date of publication of the final rule would 
provide an appropriate lead-time for generators powered by one and two 
cylinder Class II engines. The Commission is proposing an effective 
date of three years from the date of publication of the final rule for 
generators powered by handheld and Class I engines. This longer period 
to become compliant addresses manufacturers' concerns that there may be 
different challenges associated with accommodating the necessary 
emission control technologies on these smaller engines. In addition, 
later compliance dates could potentially reduce the impact on 
manufacturers of generators, including small manufacturers, by 
providing them with more time to develop engines that would meet the 
requirements of the proposed rule, or, in the case of small 
manufacturers that do not manufacture the engines used in their 
generators, by providing them with additional time to find a supplier 
for compliant engines so that their production of generators would not 
be interrupted.

[[Page 83609]]

XVI. Proposed Findings

    The CPSA requires the Commission to make certain findings when 
issuing a consumer product safety standard. Specifically, the CPSA 
requires that the Commission consider and make findings about the 
degree and nature of the risk of injury; the number of consumer 
products subject to the rule; the need of the public for the product 
and the probable effect on utility, cost, and availability of the 
product; and other means to achieve the objective of the rule, while 
minimizing the impact on competition, manufacturing, and commercial 
practices. The CPSA also requires that the Commission find that the 
rule is reasonably necessary to eliminate or reduce an unreasonable 
risk of injury associated with the product and issuing the rule must be 
in the public interest. 15 U.S.C. 2058(f)(3).
    In addition, the Commission must find that: (1) If an applicable 
voluntary standard has been adopted and implemented, that compliance 
with the voluntary standard is not likely to reduce adequately the risk 
of injury, or compliance with the voluntary standard is not likely to 
be substantial; (2) that benefits expected from the regulation bear a 
reasonable relationship to its costs; and (3) that the regulation 
imposes the least burdensome requirement that would prevent or 
adequately reduce the risk of injury. Id. These findings are discussed 
below.
    Degree and nature of the risk of injury.
    Carbon monoxide is a colorless, odorless, poisonous gas formed 
during incomplete combustion of fossil fuels, such as the fuels used in 
engines that power portable generators. Mild CO poisoning symptoms 
include headaches, lightheadedness, nausea, and fatigue. More severe CO 
poisoning can result in progressively worsening symptoms of vomiting, 
confusion, loss of consciousness, coma, and ultimately, death. The high 
CO emission rate of current generators can result in situations in 
which the COHb levels of exposed individuals rise suddenly and steeply, 
causing them to experience rapid onset of confusion, loss of muscular 
coordination, and loss of consciousness.
    As of May 21, 2015, CPSC databases contained reports of at least 
751 generator-related consumer CO poisoning deaths resulting from 562 
incidents, which occurred from 2004 through 2014. Due to incident 
reporting delays, statistics for the two most recent years, 2013 and 
2014, are incomplete, because data collection is still ongoing, and the 
death count most likely will increase in future reports.
    Based on NEISS, the Commission estimates that for the 9-year period 
of 2004 through 2012, there were 8,703 CO injuries seen in emergency 
departments (EDs) associated with portable generators. The Commission 
considers this number to represent a lower bound on the true number of 
generator-related CO injuries treated in EDs from 2004-2012. According 
to Injury Cost Model (ICM) estimates, there were an additional 16,660 
medically-attended CO injuries involving generators during 2004-2012.
    Number of consumer products subject to the rule.
    For the U.S. market for the years 2010 through 2014, about 6.9 
million gasoline-powered portable generators were shipped for consumer 
use, or an average of about 1.4 million units per year. Shipments of 
nearly 1.6 million units in 2013 made it the peak year for estimated 
sales during this period. Consumer demand for portable generators from 
year-to-year fluctuates with major power outages, such as those caused 
by tropical or winter storms. Portable generators purchased by 
consumers and in household use generally range from under 1 kW of rated 
power up to perhaps 15 kW of rated power. In the last 10 to 15 years, 
the U.S. market has shifted towards smaller, less powerful units.
    The need of the public for portable generators and the effects of 
the rule on their utility, cost, and availability.
    Portable generators that are the subject of the proposed standard 
commonly are purchased by consumers to provide electrical power during 
emergencies (such as during outages caused by storms), during other 
times when electrical power to the home has been shut off, when power 
is needed at locations around the home without access to electricity, 
and for recreational activities (such as during camping or recreational 
vehicle trips).
    The proposed rule is based on technically feasible CO emission 
rates, so that the function of portable generators is unlikely to be 
adversely affected by the rule. Moreover, there may be a positive 
change in utility in terms of fuel efficiency, greater ease of 
starting, product quality, and safety of portable generators. There may 
be a negative effect on the utility of portable generators, however, to 
the extent consumers are unable to purchase generators due to increased 
retail prices.
    In terms of retail price information, the Commission's review found 
that generators with handheld engines ranged in price from $133 to 
$799, with an average price of about $324. Generators with non-handheld 
Class I engines had a wide price range, from $190 to over $2,000, with 
an average price of $534. Generators with one-cylinder Class II engines 
ranged in price from $329 to $3,999, with an average price of $1,009. 
Generators with two-cylinder Class II engines ranged in price from 
$1,600 to $4,999, and the average price of these units was $2,550.
    Aggregate estimated compliance costs to manufacturers of portable 
generators average approximately $113 per unit for engine and muffler 
modifications necessary to comply with the CO emission requirements of 
the proposed standard. The net estimated manufacturing costs per unit 
to comply with the proposed standard is $114 for handheld engines, $113 
for Class I engines, $110 for Class II, one cylinder engines, and $138 
for Class II, two cylinder engines.
    The expected product modifications to produce complying generators 
(EFI & catalysts) are available to manufacturers, and the Commission 
does not have any indication that firms would exit the market because 
of the rule. Therefore, the availability of portable generators would 
not likely be affected by the rule.
    Other means to achieve the objective of the rule, while minimizing 
the impact on competition and manufacturing.
    The Commission considered alternatives to achieving the objective 
of the rule of reducing unreasonable risks of injury and death 
associated with portable generators. For example, the Commission 
considered less stringent CO emission rates for portable generators; 
however, cost savings from less-stringent CO emission requirements 
likely would be less than expected reductions in the benefits, so that 
the net benefits of the rule probably would decrease under this 
regulatory alternative. The Commission also considered including an 
option for reducing CO emissions through use of automatic shutoff 
systems, which could potentially reduce the impact of the proposed rule 
by providing an additional option for complying with the proposed rule; 
however, because of unresolved issues concerning an automatic shutoff, 
the Commission does not believe that a regulatory alternative based on 
automatic shutoff technology instead of reduced emissions is feasible 
for hazard reduction at this time.
    Unreasonable risk.
    As of May 21, 2015, CPSC databases contained reports of at least 
751 generator-related consumer CO poisoning deaths resulting from 562 
incidents, which occurred from 2004 through 2014. Due to incident 
reporting

[[Page 83610]]

delays, statistics for the two most recent years, 2013 and 2014, are 
incomplete, because data collection is still ongoing, and the death 
count most likely will increase in future reports.
    Based on NEISS, the Commission estimates that for the 9-year period 
of 2004 through 2012, there were 8,703 CO injuries seen in emergency 
departments (EDs) associated with portable generators. The Commission 
considers this number to represent a lower bound on the true number of 
generator-related CO injuries treated in EDs from 2004-2012. According 
to Injury Cost Model (ICM) estimates, there were an additional 16,660 
medically-attended CO injuries involving generators during 2004-2012.
    The Commission estimates that the rule would result in aggregate 
net benefits of about $145 million annually. On a per-unit basis, the 
Commission estimates the present value of the expected benefits per 
unit for all units to be $227; the expected costs to manufacturers plus 
the lost consumer surplus per unit to be $116; and the net benefits per 
unit to be $110. The Commission concludes preliminarily portable 
generators pose an unreasonable risk of injury and finds that the 
proposed rule is reasonably necessary to reduce that unreasonable risk 
of injury.
    Public interest.
    This proposed rule is intended to address an unreasonable risk of 
injury and death posed by portable generators. The Commission believes 
that adherence to the requirements of the proposed rule will reduce 
portable generator deaths and injuries in the future; thus, the rule is 
in the public interest.
    Voluntary standards.
    The Commission is aware of two U.S. voluntary standards that are 
applicable to portable generators, UL 2201--Safety Standard for 
Portable Generator Assemblies, and ANSI/PGMA G300-2015--Safety and 
Performance of Portable Generators. These standards include the same 
requirements set forth in the mandatory CPSC portable generator label 
but do not otherwise address the risks related to CO poisoning. The 
Commission does not believe the standards are adequate because they 
fail to address the risk of CO hazard beyond the CPSC mandatory 
labeling requirement. The Commission is unaware of any portable 
generator that has been certified to either of the standards, and as 
such it is unlikely whether there would be substantial compliance with 
it if CO emissions requirements were incorporated.
    Relationship of benefits to costs.
    The aggregate annual benefits and costs of the rule are estimated 
to be about $298 million and $153 million, respectively. Aggregate net 
benefits from the rule, therefore, are estimated to be about $145 
million annually. On a per unit basis, the Commission estimates the 
present value of the expected benefits per unit for all units to be 
$227. The Commission estimates the expected costs to manufacturers plus 
the lost consumer surplus per unit to be $116. Based on this analysis, 
the Commission preliminarily finds that the benefits expected from the 
rule bear a reasonable relationship to the anticipated costs of the 
rule.
    Least burdensome requirement that would adequately reduce the risk 
of injury.
    The Commission considered less-burdensome alternatives to the 
proposed rule on portable generators, but preliminarily concluded that 
none of these alternatives would adequately reduce the risk of injury.
    (1) The Commission considered not issuing a mandatory rule, but 
instead relying upon voluntary standards. As discussed previously, the 
Commission does not believe that either voluntary standard adequately 
addresses the CO risk of injury and death associated with portable 
generators. Furthermore, in the absence of any indication that a 
portable generator has been certified to either standard, the 
Commission cannot determine that there would be substantial compliance 
by industry.
    (2) The Commission considered excluding portable generators with 
two cylinder Class II engines from the scope of the rule. The 
Commission estimates that net benefits of the proposed rule range from 
about $100 to about $140 per generator for the models with handheld, 
Class I and one-cylinder Class II engines. However, the Commission 
estimates net benefits of negative $135 for the models with two-
cylinder Class II engines. Consequently, excluding portable generators 
with two cylinder Class II engines would result in a less burdensome 
alternative. However, it is possible that exclusion of generators with 
two-cylinder Class II engines from the scope of the rule could create 
an economic incentive for manufacturers of generators with larger one-
cylinder engines to either switch to two-cylinder engines for those 
models, or if they already have two-cylinder models in their product 
lines, they could be more likely to drop larger one-cylinder models 
from their product lines. Because the Commission lacks more specific 
information on the generators with Class II twin cylinder engines, the 
Commission is proposing this rule with the broader scope of including 
these generators. The Commission welcomes comments on inclusion of 
portable generators with Class II twin cylinder engines, or Class 2 
twin cylinder generators, in the scope of the rule.
    (3) The Commission considered higher allowable CO emission rates, 
which might result in costs savings from lower costs associated with 
catalysts (if they would not be required, or if less-costly materials 
could suffice), less-extensive engine modifications (other than EFI-
related costs) and less-extensive generator housing modifications (if 
housing enlargement and other retooling would be minimized). However, 
based on Commission estimates, it seems likely that cost savings from 
less-stringent CO emission requirements would be less than expected 
reductions in benefits. Therefore, the Commission is not proposing this 
alternative.

XVII. Ex Ante Retrospective Review

    As set forth in the Commission's Plan for Retrospective Review of 
Existing Rules (Retrospective Review Plan) (http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Rulemaking/DraftrulereviewplanSeptember2015Final.pdf) and consistent with the 
Regulatory Flexibility Act, as applicable, the Commission has 
established certain methods and processes for identifying and 
reconsidering certain rules that warrant repeal or modification, 
including rules that would benefit from strengthening, complementing, 
or modernizing. Consistent with the Retrospective Review Plan's methods 
and procedures, which permit the Commission to include retrospective 
review provisions in new rulemakings, the Commission is requesting 
comments on whether to develop ex ante criteria for the retrospective 
review of this proposed rule.

XVIII. Request for Comments

    We invite all interested persons to submit comments on any aspect 
of the proposed rule. More specifically, the Commission seeks comments 
on the following:
     The cost or other impacts of the certification 
requirements under Section 14 of the CPSA and whether it would be 
feasible to use the results of tests conducted for certifying 
compliance with EPA requirements to certify compliance with the 
proposed rule;
     The product manufacture or import limits and the base 
period in the proposed anti-stockpiling provision;

[[Page 83611]]

     Prospective use (e.g., costs, applicability and 
challenges) of battery-less EFI for portable generators;
     Costs of new designs and tooling that may be required for 
generator frames and housings to accommodate additional components, 
such as batteries for generators with handheld or Class I engines, and 
to address reported concerns with heat dissipation.
     Information on potential challenges in accommodating new 
features in handheld and Class I engines to comply with the proposed 
rule, as well as on components and technologies that might be available 
to meet these challenges and moderate the impacts of the proposed rule 
on handheld and Class I engines.
     Costs per unit element for testing and certification, 
including what additional costs per unit element might be if the 
Commission required specific testing requirements;
     Costs firms experience with testing and certification of 
engines for EPA emissions testing;
     Advantages and disadvantages of setting performance 
requirements at 17 percent oxygen instead of normal oxygen as well as 
comments on the technically feasible CO emission rates for generators 
operating at 17 percent oxygen, for each of the generator categories.
     Based on estimates made for EPA, estimated variable costs 
for a pressurized oil system would be about $19 for small spark-
ignition engines that that now lack this feature. In the view of the 
Directorate for Engineering Sciences, pressurized lubrication systems 
would not be necessary to comply with the draft standard. We welcome 
comments on this issue.
     Whether to exclude portable generators with two-cylinder 
Class II engines from the final rule, and if two-cylinder Class II 
engines were to be excluded, whether a limit on displacement should be 
included to avoid developing a market for small two-cylinder engines 
for portable generators that would be exempt from the rule;
     Information on the benefits and costs that would be 
associated with different CO emission rates;
     Information and data about the expected range of 
manufacturing variability for CO emissions from EFI equipped small 
spark ignited engines, including data on emissions variability from 
production target values and expected manufacturing tolerances.
     Information about the benefits and costs associated with 
altering the performance requirements for CO emissions such that an 
alternate performance requirement could be based on limits on those 
emissions when the generator is operating in air with reduced oxygen 
content of 17 percent oxygen (or a different reduced level) rather than 
normal atmospheric oxygen (approximately 20.9 percent), as proposed; if 
so, what that performance requirement should be and how should CPSC 
should test to verify compliance.
     Test methods staff use for determining CO emissions from 
generators in normal atmospheric oxygen levels (approximately 20.9 
percent) and at reduced oxygen levels (as described in staff's briefing 
package), as well information on benefits and costs that could be 
associated with requiring those specific methods for evaluation and the 
benefits and costs of not requiring a specific test method.
     The appropriateness of compliance dates that are one year 
from the date of publication of the final rule for portable generators 
with Class II engines, or class 2 generators, and three years from the 
date of publication of the final rule for generators with handheld and 
Class I engines, or handheld generators and class 1 generators.
     Whether the Commission should instead adopt a compliance 
date that is 18 months from the date of publication of the final rule 
for generators with handheld and Class I engines, or handheld 
generators and class 1 generators.
     Possible alternative technologies that would address the 
carbon monoxide hazard associated with portable generators other than 
or in addition to reduced carbon monoxide generation, such as, but not 
limited to, viable shut-off technology. For any proposed alternate 
technology, please provide a description of how its performance would 
be characterized, any challenges to implementation, data showing the 
viability of the technology in this application and any other 
information that would help evaluate the efficacy and cost of the 
alternate approach.
     The feasibility of continuing to lower in the future the 
CO rate requirements for portable generators as technology advances and 
whether the Commission can make related findings that CO emission rates 
lower than those set forth in the proposed rule will further reduce the 
risk of death and injury associated with this hazard. Provide 
information on a timetable or other automatic mechanism that would 
trigger a review of the emission rates for purposes of evaluating the 
feasibility of establishing lower rates as well as any metrics that 
would be used to evaluate the state of the technology for the purpose 
of lowering the CO rates in the rule.
     Potential increase in fuel economy resulting from this 
proposed performance standard and quantification of costs or benefits 
associated with such increase.
     Potential impact of this proposed performance standard on 
the market for handheld generators and costs or benefits associated 
with such impact.
     Potential impact noise emissions associated with this 
proposed performance standard and any advantages or disadvantages of 
such impact.
     The need for retrospective review of this proposed rule, 
including the need for development of ex ante criteria, pursuant to the 
selection criteria set forth in the Commission's Retrospective Review 
Plan. Examples of potential criteria for any future retrospective 
review of this proposed rule include, but are not limited to: The 
appropriate data points necessary to evaluate such measures, the 
appropriate interval for such retrospective review, and the appropriate 
goals to define success in each measure.
     Additional information on portable generator sales and 
use.
    Comments should be submitted in accordance with the instructions in 
the ADDRESSES section at the beginning of this document.

XIX. Conclusion

    For the reasons stated in this preamble, the Commission proposes 
requirements for portable generators to address an unreasonable risk of 
injury associated with portable generators.

List of Subjects in 16 CFR Part 1241

    Consumer protection, Imports, Information, Safety.

    For the reasons discussed in the preamble, the Commission proposes 
to amend Title 16 of the Code of Federal Regulations as follows:

0
1. Add part 1241 to read as follows:

PART 1241--SAFETY STANDARD FOR PORTABLE GENERATORS

Sec.
1241.1 Scope, purpose and compliance dates.
1241.2 Definitions.
1241.3 Requirements.
1241.4 Test procedures.
1241.5 Prohibited stockpiling.
1241.6 Findings.

    Authority:  15 U.S.C. 2056, 2058 and 2076.


Sec.  1241.1  Scope, purpose and compliance dates.

    (a) This part 1241, a consumer product safety standard, establishes

[[Page 83612]]

requirements for portable generators, as defined in Sec.  1241.2(b). 
The standard includes requirements for carbon monoxide emission rates 
for categories of portable generators. These requirements are intended 
to reduce an unreasonable risk of injury and death associated with 
portable generators.
    (b) For purposes of this rule, portable generators include single 
phase; 300 V or lower; 60 hertz; portable generators driven by small 
handheld and non-handheld (as defined by the Environmental Protection 
Agency) spark-ignited utility engines intended for multiple use which 
are provided only with receptacle outlets for the AC output circuits 
and intended to be moved, though not necessarily with wheels. For 
purposes of this rule, portable generators do not include:
    (1) Permanently installed generators;
    (2) 50 hertz generators;
    (3) Marine generators;
    (4) Trailer mounted generators;
    (5) Generators installed in recreational vehicles;
    (6) Generators intended to be pulled by vehicles;
    (7) Generators that are part of welding machines;
    (8) Generators powered by compression-ignition engines fueled by 
diesel.
    (c) Class 2 single cylinder and two cylinder generators, as defined 
in Sec.  1241.2(c) and (d) manufactured or imported on or after [date 
that is 365 days after publication of a final rule] shall comply with 
the requirements stated in Sec.  1241.3(b)(2) and (3). Handheld 
generators and Class 1 generators, as defined in Sec.  1241.2(a) and 
(b), manufactured or imported on or after [date that is 3 years after 
publication of a final rule], shall comply with the requirements stated 
in Sec.  1241.3(b)(1).


Sec.  1241.2  Definitions.

    In addition to the definitions in section 3 of the Consumer Product 
Safety Act (15 U.S.C. 2051), the following definitions apply for 
purposes of this part 1241.
    (a) Handheld generator means a generator powered by a spark ignited 
(SI) engine with displacement of 80 cc or less.
    (b) Class 1 generator means a generator powered by an SI engine 
with displacement greater than 80 cc but less than 225 cc.
    (c) Class 2 single cylinder generator means a generator powered by 
an SI engine with one cylinder having displacement of 225 cc or 
greater, up to a maximum engine power of 25 kW.
    (d) Class 2 two cylinder generator means a generator powered by an 
SI engine with two cylinders having a total displacement of 225 cc or 
greater, up to a maximum engine power of 25 kW.


Sec.  1241.3  Requirements.

    (a) When tested in accordance with the test procedures stated in 
Sec.  1241.4 (or similar test procedures), all portable generators 
covered by this standard shall meet the requirements stated in 
paragraph (b) of this section.
    (b) Emission rate requirements.
    (1) Handheld generators and Class 1 generators must not exceed a 
weighted CO emission rate of 75 grams per hour (g/hr).
    (2) Class 2 single cylinder generators must not exceed a weighted 
CO emission rate of 150 g/hr.
    (3) Class 2 two cylinder generators must not exceed a weighted CO 
emission rate of 300 g/hr.


Sec.  1241.4  Test procedures.

    (a) Any test procedure that will accurately determine the carbon 
monoxide emission rate of the portable generator may be used. CPSC uses 
the test procedure stated in this section to determine compliance with 
the standard.
    (b) Definitions.
    (1) Load bank and power meter means an AC electric resistor load 
bank used to simulate steady electric loads on the generator. The load 
bank shall be capable of adjustment to within 5 percent of each 
required load condition. A power meter is used to measure the actual 
electrical load delivered by the generator with an accuracy of 5 percent.
    (2) Fuel and lubricants means fuel and lubricants that meet 
manufacturer's specifications for the generator being tested.
    (3) Emission measurement system means the constant volume sampling 
(CVS) emission measurement system described in 40 CFR parts 1054 and 
1065.
    (4) Maximum generator load means the maximum output power 
capability of the generator assembly as determined by the maximum 
generator load determination procedures. The maximum generator load is 
used to establish the 6-mode load profile.
    (c) Determining maximum generator load.
    (1) Power saturation method for conventional (non-inverter) 
generator assemblies.
    (i) Ensure test facility is at ambient conditions 15-30 [deg]C (60-
85 [deg]F) and approximately 20.9 percent oxygen.
    (ii) Apply a load greater than 60 percent of the manufacturer's 
rated continuous power for a minimum of 20 minutes to warm the 
generator to operating temperature.
    (iii) Monitoring voltage and frequency, increase the load applied 
to the generator to the maximum observed power output without causing 
the voltage or frequency to deviate from the following tolerances:
    (A) Voltage Tolerance: 10 percent of the nameplate 
rated voltage.
    (B) Frequency Tolerance: 5 percent of the nameplate 
rated frequency.
    (iv) Maintain the maximum observed power output until the operating 
temperature of the engine stabilizes. The generator is at stable 
operating temperature when the oil temperature varies by less than 2 
[deg]C (4 [deg]F) over three consecutive readings taken 15 minutes 
apart. For the purpose of determining maximum generator load, if an 
overload protection device is present, it shall not activate for a 
period of 45 minutes from the initial operating temperature stability 
reading. The load may need to be adjusted to maintain the maximum 
observed power output while the generator temperatures are stabilizing. 
Record voltage, frequency, amperage, power, and oil and ambient air 
temperature.
    (v) The maximum generator load is the power supplied by the 
generator assembly that satisfies the tolerances in paragraph 
(c)(1)(iii) of this section when the generator is at stable operating 
temperature as defined in paragraph (c)(iv) of this section. Record the 
maximum generator load.
    (2) Power saturation method for inverter generator assemblies.
    (i) Ensure test facility is at ambient conditions 15-30 [deg]C (60-
85 [deg]F) and approximately 20.9 percent oxygen.
    (ii) Apply a load greater than 60 percent of the manufacturer's 
rated continuous power for a minimum of 20 minutes to warm the 
generator to operating temperature.
    (iii) Increase the load applied to the generator to the maximum 
observed power output.
    (iv) Maintain the maximum observed power output until the operating 
temperature of the engine stabilizes. The generator is at stable 
operating temperature when the oil temperature varies by less than 2 
[deg]C (4 [deg]F) over three consecutive readings taken 15 minutes 
apart. For the purpose of determining maximum generator load, if an 
overload protection device is present, it shall not activate for a 
period of 45 minutes from the initial operating temperature stability 
reading. The load may need to be adjusted to maintain the maximum 
observed power output while the generator temperatures are stabilizing. 
Record voltage, frequency, amperage,

[[Page 83613]]

power, and oil and ambient air temperature.
    (v) Maximum generator load is the maximum observed power output 
that satisfies the criteria defined in paragraph (c)(2)(iv) of this 
section. Record the maximum generator load.
    (d) Test method to determine the modal CO emission rates of a 
portable generator. To determine the weighted CO emission rate of a 
portable generator assembly, determine the modal CO emission rates at 
six discrete generator loads based on maximum generator load using a 
CVS emissions tunnel described in 40 CFR parts 1054 and 1065, and 
calculate the weighted CO emission rate. All tests shall be performed 
under typical operating conditions at an ambient air temperature of 15-
30 [deg]C (60-85 [deg]F) and approximately 20.9 percent oxygen. Testing 
shall be performed on a complete generator assembly and load shall be 
applied through the generators receptacle panel. If a generator is 
equipped with a system that provides different engine operating modes 
such as a fuel economy mode, the generator shall be tested to this 
Section in all available modes. CO emission performance shall be 
determined by the highest weighted CO emission rate calculated in 
paragraph (e) of this section.
    (1) Place the generator assembly in front of the CVS tunnel with 
the exhaust facing towards the collector. Connect the load bank and 
apply a load greater than 60 percent of the manufacturer's rated 
continuous power for a minimum of 20 minutes to warm the generator to 
operating temperature.
    (2) Adjust the load bank to apply the appropriate mode calculated 
from the maximum generator load. Modal testing shall be performed in 
order from mode 1 to mode 6. Mode points are determined by a percentage 
of the maximum generator load:

(i) Mode 1: 100 percent of maximum generator load
(ii) Mode 2: 75 percent of maximum generator load
(iii) Mode 3: 50 percent of maximum generator load
(iv) Mode 4: 25 percent of maximum generator load
(v) Mode 5: 10 percent of maximum generator load
(vi) Mode 6: 0 percent of maximum generator load

    (3) Stabilize oil and head temperatures by operating at mode for 5 
minutes. After the 5 minute stabilization period, record emissions for 
at least 2 minutes at a minimum rate of 0.1 Hz with the prescribed mode 
applied. Record the mean CO emission value for that mode during the 
data acquisition period.
    (4) Repeat steps in paragraphs (d)(2) to (d)(4) for the successive 
modes listed in paragraph (d)(2).
    (5) When all modal mean CO emission rates have been determined, 
calculate and report the weighted CO emission rate using guidance in 
paragraph (e).
    (e) Weighted CO emission rate calculation and reporting.
    (1) Calculate the weighted CO emission rate using the mean CO 
emission rates determined in paragraph (d).

mw = 0.09 x m1 + 0.20 x m2 + 0.29 x m3 + 0.30 x m4 + 0.07 x m5 + 0.05 x 
m6

Where,

mw = Weighted CO emission Rate (g/hr)
m1 = Mean CO emission Rate at Mode 1 (g/hr)
m2 = Mean CO emission Rate at Mode 2 (g/hr)
m3 = Mean CO emission Rate at Mode 3 (g/hr)
m4 = Mean CO emission Rate at Mode 4 (g/hr)
m5 = Mean CO emission Rate at Mode 5 (g/hr)
m6 = Mean CO emission Rate at Mode 6 (g/hr)

    (2) Report the following results for the generator:
    (i) Weighted CO emission rate in grams per hour.
    (ii) Modal information including the mean CO emission, and head and 
oil temperature.
    (iii) Maximum generator load information as determined in paragraph 
(c). Include maximum generator load, voltage, amperage, and frequency.


Sec.  1241.5  Prohibited stockpiling.

    (a) Base period. The base period for portable generators is any 
period of 365 consecutive days, chosen by the manufacturer or importer, 
in the 5-year period immediately preceding the promulgation of the 
final rule.
    (b) Prohibited acts. Manufacturers and importers of portable 
generators shall not manufacture or import portable generators that do 
not comply with the requirements of this part in any 12-month period 
between (date of promulgation of the rule) and (effective/compliance 
date of the rule) at a rate that is greater than 125% of the rate at 
which they manufactured or imported portable generators with engines of 
the same class during the base period for the manufacturer.


Sec.  1241.6  Findings.

    (b) General. In order to issue a consumer product safety standard 
under the Consumer Product Safety Act, the Commission must make certain 
findings and include them in the rule. 15 U.S.C. 2058(f)(3). These 
findings are discussed in this section.
    (c) Degree and nature of the risk of injury. Carbon monoxide is a 
colorless, odorless, poisonous gas formed during incomplete combustion 
of fossil fuels, such as the fuels used in engines that power portable 
generators. Mild CO poisoning symptoms include headaches, 
lightheadedness, nausea, and fatigue. More severe CO poisoning can 
result in progressively worsening symptoms of vomiting, confusion, loss 
of consciousness, coma, and ultimately, death. The high CO emission 
rate of current generators can result in situations in which the COHb 
levels of exposed individuals rise suddenly and steeply, causing them 
to experience rapid onset of confusion, loss of muscular coordination, 
and loss of consciousness.
    (1) As of May 21, 2015, CPSC databases contained reports of at 
least 751 generator-related consumer CO poisoning deaths resulting from 
562 incidents, which occurred from 2004 through 2014. Due to incident 
reporting delays, statistics for the two most recent years, 2013 and 
2014, are incomplete, because data collection is still ongoing, and the 
death count most likely will increase in future reports.
    (2) Based on NEISS, the Commission estimates that for the 9-year 
period of 2004 through 2012, there were 8,703 CO injuries seen in 
emergency departments (EDs) associated with portable generators. The 
Commission considers this number to represent a lower bound on the true 
number of generator-related CO injuries treated in EDs from 2004-2012. 
According to Injury Cost Model (ICM) estimates, there were an 
additional 16,660 medically-attended CO injuries involving generators 
during 2004-2012.
    (d) Number of consumer products subject to the rule. For the U.S. 
market for the years 2010 through 2014, about 6.9 million gasoline-
powered portable generators were shipped for consumer use, or an 
average of about 1.4 million units per year. Shipments of nearly 1.6 
million units in 2013 made it the peak year for estimated sales during 
this period. Consumer demand for portable generators from year-to-year 
fluctuates with major power outages, such as those caused by tropical 
or winter storms. Portable generators purchased by consumers and in 
household use generally range from under 1 kW of rated power up to 
perhaps 15 kW of rated power. In the last 10 to 15 years,

[[Page 83614]]

the U.S. market has shifted towards smaller, less powerful units.
    (e) The need of the public for portable generators and the effects 
of the rule on their utility, cost, and availability. Portable 
generators that are the subject of the proposed standard commonly are 
purchased by household consumers to provide electrical power during 
emergencies (such as during outages caused by storms), during other 
times when electrical power to the home has been shut off, when power 
is needed at locations around the home without access to electricity, 
and for recreational activities (such as during camping or recreational 
vehicle trips).
    (1) The proposed rule is based on technically feasible CO emission 
rates, so that the function of portable generators is unlikely to be 
adversely affected by the rule. There may be an effect on the utility 
of portable generators to the extent consumers are unable to purchase 
generators due to increased retail prices. There may be a positive 
change in utility in terms of fuel efficiency, greater ease of 
starting, product quality, and safety of portable generators.
    (2) In terms of retail price information, the Commission's review 
found that generators with handheld engines ranged in price from $133 
to $799, with an average price of about $324. Generators with non-
handheld Class I engines had a wide price range, from $190 to over 
$2,000, with an average price of $534. Generators with one-cylinder 
Class II engines ranged in price from $329 to $3,999 with an average 
price of $1,009. Generators with two-cylinder Class II engines ranged 
in price from $1,600 to $4,999 and the average price of these units was 
$2,550.
    (3) Aggregate estimated compliance costs to manufacturers of 
portable generators average approximately $113 per unit for engine and 
muffler modifications necessary to comply with the CO emission 
requirements of the proposed standard. The net estimated manufacturing 
costs per unit to comply with the proposed standard is $114 for 
handheld engines, $113 for Class I engines, $110 for Class II, one 
cylinder engines, and $138 for Class II, two cylinder engines.
    (4) The expected product modifications to produce complying 
generators (EFI & catalysts) are available to manufacturers, and the 
Commission does not have any indication that firms would exit the 
market because of the rule. Therefore, the availability of portable 
generators would not likely be affected by the rule.
    (f) Other means to achieve the objective of the rule, while 
minimizing the impact on competition and manufacturing. The Commission 
considered alternatives to achieving the objective of the rule of 
reducing unreasonable risks of injury and death associated with 
portable generators. For example, the Commission considered less 
stringent CO emission rates for portable generators; however, the 
Commission found that cost savings from less-stringent CO emission 
requirements likely would be less than expected reductions in the 
benefits, so that the net benefits of the rule probably would decrease 
under this regulatory alternative. The Commission also considered 
including an option for reducing CO emissions through use of automatic 
shutoff systems, which could potentially reduce the impact of the 
proposed rule by providing an additional option for complying with the 
proposed rule; however, because of unresolved issues concerning an 
automatic shutoff, the Commission does not believe that a regulatory 
alternative based on automatic shutoff technology instead of reduced 
emissions is feasible for hazard reduction at this time.
    (g) Unreasonable risk.
    (1) As of May 21, 2015, CPSC databases contained reports of at 
least 751 generator-related consumer CO poisoning deaths resulting from 
562 incidents, which occurred from 2004 through 2014. Due to incident 
reporting delays, statistics for the two most recent years, 2013 and 
2014, are incomplete, because data collection is still ongoing, and the 
death count most likely will increase in future reports.
    (2) Based on NEISS, the Commission estimates that for the 9-year 
period of 2004 through 2012, there were 8,703 CO injuries seen in 
emergency departments (EDs) associated with portable generators. The 
Commission considers this number to represent a lower bound on the true 
number of generator-related CO injuries treated in EDs from 2004-2012. 
According to Injury Cost Model (ICM) estimates, there were an 
additional 16,660 medically-attended CO injuries involving generators 
during 2004-2012.
    (3) The Commission estimates that the rule would result in 
aggregate net benefits of about $145 million annually. On a per-unit 
basis, the Commission estimates the present value of the expected 
benefits per unit for all units to be $227; the expected costs to 
manufacturers plus the lost consumer surplus per unit to be $116; and 
the net benefits per unit to be $110. The Commission concludes 
preliminarily portable generators pose an unreasonable risk of injury 
and finds that the proposed rule is reasonably necessary to reduce that 
unreasonable risk of injury.
    (g) Public interest. This proposed rule is intended to address an 
unreasonable risk of injury and death posed by portable generators. The 
Commission believes that adherence to the requirements of the proposed 
rule will reduce portable generator deaths and injuries in the future; 
thus, the rule is in the public interest.
    (h) Voluntary standards. The Commission is aware of two U.S. 
voluntary standards that are applicable to portable generators, UL 
2201--Safety Standard for Portable Generator Assemblies, and ANSI/PGMA 
G300-2015--Safety and Performance of Portable Generators. These 
standards include the same requirements set forth mandatory CPSC 
portable generator label but do not otherwise address the risks related 
to CO poisoning. The Commission does not believe the standards are 
adequate because they fail to address the risk of CO hazard beyond the 
CPSC mandatory labeling requirement. The Commission is unaware of any 
portable generator that has been certified to either of the standards, 
and as such it is unlikely whether there would be substantial 
compliance with it if CO emissions requirements were incorporated.
    (i) Relationship of benefits to costs. The aggregate annual 
benefits and costs of the rule are estimated to be about $298 million 
and $153 million, respectively. Aggregate net benefits from the rule, 
therefore, are estimated to be about $145 million annually. On a per 
unit basis, the Commission estimates the present value of the expected 
benefits per unit for all units to be $227. The Commission estimates 
the expected costs to manufacturers plus the lost consumer surplus per 
unit to be $116. Based on this analysis, the Commission finds 
preliminary that the benefits expected from the rule bear a reasonable 
relationship to the anticipated costs of the rule.
    (j) Least burdensome requirement that would adequately reduce the 
risk of injury. (1) The Commission considered less-burdensome 
alternatives to the proposed rule on portable generators, but concluded 
preliminary that none of these alternatives would adequately reduce the 
risk of injury.
    (2) The Commission considered not issuing a mandatory rule, but 
instead relying upon voluntary standards. As discussed previously, the 
Commission does not believe that either voluntary standard adequately 
addresses the CO risk of injury and death associated with portable 
generators. Furthermore, the Commission doubts that either of the

[[Page 83615]]

voluntary standards would have substantial compliance by industry.
    (3) Excluding portable generators with two cylinder, Class II 
engines from the scope of the rule. The Commission estimates that net 
benefits of the proposed rule range from about $100 to about $140 per 
generator for the models with handheld, Class I and one-cylinder Class 
II engines. However, net benefits were negative $135 for the models 
with two-cylinder class II engines. Consequently, excluding portable 
generators with two cylinder Class II engines would result in a less 
burdensome alternative. However, it is possible that exclusion of 
generators with two-cylinder Class II engines from the scope of the 
rule could create an economic incentive for manufacturers of generators 
with larger one-cylinder engines to either switch to two-cylinder 
engines for those models, or if they already have two-cylinder models 
in their product lines, they could be more likely to drop larger one-
cylinder models from their product lines. Because the Commission lacks 
more specific information on the generators with Class II twin cylinder 
engines, the Commission is proposing this rule with the broader scope 
of including these generators.
    (4) The Commission considered higher allowable CO emission rates, 
which might result in costs savings from lower costs associated with 
catalysts (if they would not be required, or if less-costly materials 
could suffice), less-extensive engine modifications (other than EFI-
related costs) and less-extensive generator housing modifications (if 
housing enlargement and other retooling would be minimized). However, 
based on Commission estimates, it seems likely that cost savings from 
less-stringent CO emission requirements would be less than expected 
reductions in benefits. Therefore, the Commission is not proposing this 
less burdensome alternative.

    Dated: November 3, 2016.
Todd A. Stevenson,
Secretary, Consumer Product Safety Commission.
[FR Doc. 2016-26962 Filed 11-18-16; 8:45 am]
 BILLING CODE 6355-01-P