[Federal Register Volume 87, Number 86 (Wednesday, May 4, 2022)]
[Rules and Regulations]
[Pages 26276-26295]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-08923]


=======================================================================
-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[EPA-HQ-OAR-2021-0347; FRL-8470-01-OAR]
RIN 2060-AV25


Protection of Stratospheric Ozone: Listing of HFO-1234yf Under 
the Significant New Alternatives Policy Program for Motor Vehicle Air 
Conditioning in Nonroad Vehicles and Servicing Fittings for Small 
Refrigerant Cans

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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

SUMMARY: Pursuant to the EPA's Significant New Alternatives Policy 
program, this action lists the refrigerant 2,3,3,3-tetrafluoroprop-1-
ene, also known as HFO-1234yf or R-1234yf, as acceptable, subject to 
use conditions, in the motor vehicle air conditioning end-use for 
certain types of newly manufactured nonroad (also called off-road) 
vehicles, which includes some vehicles that are also considered heavy-
duty vehicles. EPA is also adopting the current versions of the 
industry safety standards SAE J639, SAE J1739, and SAE J2844 by 
incorporating them by reference into the use conditions for the 
listings in nonroad vehicles and previous listings for certain onroad 
vehicles covered in final rules issued separately in March 2011 and 
December 2016. In addition, EPA is requiring unique servicing fittings 
for use with small refrigerant cans (two pounds or less) of 2,3,3,3-
tetrafluoroprop-1-ene that are used to service onroad and nonroad 
vehicles. Finally, EPA is adding a reference to the Agency's 
regulations under the Toxic Substances Control Act for 2,3,3,3-
tetrafluoroprop-1-ene for the listings in nonroad vehicles and previous 
listings for certain onroad vehicles.

DATES: This final rule is effective on June 3, 2022. The incorporation 
by reference of certain publications listed in the rule is approved by 
the Director of the Federal Register as of June 3, 2022.

ADDRESSES: EPA has established a docket for this action under Docket ID 
No. EPA-HQ-OAR-2021-0347. All documents in the docket are listed on the 
www.regulations.gov website. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, is not placed on the internet and will be 
publicly available only in hard copy form. Publicly available docket 
materials are available electronically through www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Chenise Farquharson, Stratospheric 
Protection Division, Office of Atmospheric Programs (Mail Code 6205 T), 
Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington, 
DC 20460; telephone number: 202-564-7768; email address: 
[email protected]. Notices and rulemakings under EPA's 
Significant New Alternatives Policy program are available on EPA's 
Stratospheric Ozone website at www.epa.gov/snap/snap-regulations.

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. General Information
    A. Executive Summary and Background
    B. SNAP Program Background
    1. Rulemaking
    2. Listing of Unacceptable/Acceptable Substitutes
    3. Petition Process
    4. 90-Day Notification
    C. Does this action apply to me?
    D. What acronyms and abbreviations are used in the preamble?
II. What is EPA finalizing in this action?
    A. Listing of HFO-1234yf as Acceptable, Subject to Use 
Conditions, for MVAC Systems in New Nonroad Vehicles
    1. What is the affected end-use?
    2. What are the ASHRAE classifications for refrigerant 
flammability?
    3. How does HFO-1234yf compare to other refrigerants for these 
MVAC applications with respect to SNAP criteria?
    4. What are the use conditions?
    B. Modifications to Use Conditions for MVAC Systems in Other 
Vehicle Types
    C. Servicing Fittings for Small Cans of HFO-1234yf
    1. What is the affected end-use?
    2. How does HFO-1234yf compare to other refrigerants for this 
MVAC application with respect to SNAP criteria?
    3. What is the use condition?
    D. Incorporation by Reference of SAE Standards
    E. What is the relationship between this SNAP rule and other 
federal rules?
    F. Response to Comments
III. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    K. Congressional Review Act (CRA)
IV. References

I. General Information

A. Executive Summary and Background

    As proposed, EPA is listing 2,3,3,3-tetrafluoroprop-1-ene, also 
known as hydrofluoroolefin (HFO)-1234yf or R-1234yf, hereafter referred 
to as ``HFO-1234yf,'' as acceptable, subject to use conditions, under 
the Significant New Alternatives Policy (SNAP) program, as of 30 days 
after publication of this final rule, for motor vehicle air 
conditioning (MVAC) systems \1\ in the following types

[[Page 26277]]

of newly manufactured (hereafter ``new'') \2\ nonroad vehicles,\3\ 
including some vehicles that are also considered heavy-duty (HD) \4\ 
vehicles:
---------------------------------------------------------------------------

    \1\ Under the SNAP program, MVAC systems are those systems that 
provide passenger comfort cooling for light-duty cars and trucks, 
heavy-duty vehicles (large pickups, delivery trucks, recreational 
vehicles, and semi-trucks), nonroad vehicles, buses, and rail 
vehicles. See final rules published on March 29, 2011 (76 FR 17488) 
and on December 1, 2016 (81 FR 86778). For informational purposes, 
we note that this includes systems that are also included in the 
definitions that apply under other provisions of EPA's regulations 
under title VI of the CAA. In this regard, we note that EPA's 
subpart F regulations at 40 CFR 82.152 define MVAC-like appliance to 
mean a mechanical vapor compression, open-drive compressor appliance 
with a full charge of 20 pounds or less of refrigerant used to cool 
the driver's or passenger's compartment of off-road vehicles or 
equipment. This includes, but is not limited to, the air-
conditioning equipment found on agricultural or construction 
vehicles. This definition is not intended to cover appliances using 
R-22 refrigerant. By contrast, EPA's subpart F regulations at 40 CFR 
82.152 define Motor vehicle air conditioner (MVAC) as ``any 
appliance that is a motor vehicle air conditioner as defined in 40 
CFR part 82, subpart B. The subpart B regulations at 40 CFR 82.32 
provide that: Motor vehicle air conditioners means mechanical vapor 
compression refrigeration equipment used to cool the driver's or 
passenger's compartment of any motor vehicle. This definition is not 
intended to encompass the hermetically sealed refrigeration systems 
used on motor vehicles for refrigerated cargo and the air 
conditioning systems on passenger buses using HCFC-22 refrigerant. 
Further, the subpart B regulations at 40 CFR 82.32 provide that: 
Motor vehicle as used in this subpart means any vehicle which is 
self-propelled and designed for transporting persons or property on 
a street or highway, including but not limited to passenger cars, 
light duty vehicles, and heavy duty vehicles. This definition does 
not include a vehicle where final assembly of the vehicle has not 
been completed by the original equipment manufacturer.
    \2\ This is intended to mean a completely new refrigeration 
circuit containing a new compressor, evaporator, condenser, and 
refrigerant tubing.
    \3\ In the past, EPA has referred to these vehicles as ``off-
road vehicles'' under the SNAP program. In this action, we are 
aligning our terminology with that of other EPA programs and using 
the term ``nonroad vehicle,'' which is defined under CAA section 216 
to mean ``a vehicle that is powered by a nonroad engine and that is 
not a motor vehicle or a vehicle used solely for competition.'' 
EPA's regulations issued under that section of the Act defining a 
nonroad engine are codified at subpart A of 40 CFR part 1068.
    \4\ Heavy-duty vehicles are often subdivided by vehicle weight 
classifications, as defined by the vehicle's gross vehicle weight 
rating (GVWR), which is a measure of the combined curb (empty) 
weight and cargo carrying capacity of the truck. Heavy-duty vehicles 
have GVWRs above 8,500. See https://www.epa.gov/emission-standards-reference-guide/vehicle-weight-classifications-emission-standards-reference-guide.
---------------------------------------------------------------------------

     Agricultural tractors with greater than 40 horsepower 
(HP);
     Self-propelled agricultural machinery;
     Compact equipment;
     Construction, forestry, and mining equipment; and
     Commercial utility vehicles.
    EPA received four comments on the proposed rule from refrigerant 
suppliers and equipment manufacturers, and all commenters strongly 
supported finalizing the rule as proposed. The comment summaries and 
EPA's responses to the comments are below in section II.F.
    EPA has previously listed HFO-1234yf as acceptable, subject to use 
conditions, in new light-duty (LD) passenger cars and trucks (76 FR 
17488; March 29, 2011) and new medium-duty passenger vehicles (MDPV), 
HD pickup trucks, and complete HD vans (81 FR 86778; December 1, 2016). 
The use conditions for those prior listings, which are intended to 
mitigate flammability and toxicity risks, require that MVAC systems 
designed to use HFO-1234yf meet the requirements of three technical 
safety standards developed by SAE International (SAE) (i.e., SAE J639, 
SAE J1739, and SAE J2844). In this action, EPA is requiring the same 
use conditions, with certain updates discussed below, for MVAC systems 
designed to use HFO-1234yf in certain new nonroad vehicles. EPA is 
listing HFO-1234yf as acceptable, subject to use conditions, after its 
evaluation of human health and environmental information on various 
substitutes submitted to the SNAP program. In listing HFO-1234yf as 
acceptable, subject to use conditions, this action provides additional 
flexibility for industry stakeholders by expanding the list of 
acceptable substitutes for certain types of nonroad vehicles.
    EPA is also adopting the current versions of SAE J639, SAE J1739, 
and SAE J2844 by incorporating them by reference into the use 
conditions for the nonroad vehicles addressed in this action. EPA is 
also modifying the use conditions for the previous listings of HFO-
1234yf in certain onroad vehicles to replace the references to older 
versions of the three SAE standards with references to the current 
versions. The current versions of the three standards are SAE J639 
(revised November 2020), ``Safety and Design Standards for Motor 
Vehicle Refrigerant Vapor Compression Systems;'' SAE J1739 (revised 
January 2021), ``Potential Failure Mode and Effects Analysis (FMEA) 
Including Design FMEA, Supplemental FMEA-MSR, and Process FMEA;'' and 
SAE J2844 (revised January 2013), ``R-1234yf (HFO-1234yf) New 
Refrigerant Purity and Container Requirements for Use in Mobile Air-
Conditioning Systems.''
    In addition, EPA is including a use condition, which requires 
unique servicing fittings, to provide for servicing MVAC systems in the 
nonroad vehicles addressed in this action, including use of small 
refrigerant cans (two pounds or less). For the previous listings of 
HFO-1234yf in certain onroad vehicles, EPA is revising the use 
conditions to require unique servicing fittings for use with small cans 
(two pounds or less).
    Finally, EPA is including a reference to the Agency's Significant 
New Use Rule (SNUR) for HFO-1234yf under the Toxic Substances Control 
Act (80 FR 37166, June 30, 2015) in Appendix B subpart G of part 82, 
under the `Comments' column, for the listings of HFO-1234yf for the 
nonroad vehicles addressed in this action, as well as for all the 
previous listings of HFO-1234yf in certain onroad vehicles. The SNUR 
states that commercial users or consumers can only recharge MVAC 
systems with HFO-1234yf where the original charging of the system with 
HFO-1234yf was done by the Original Equipment Manufacturer (OEM).
    The Agency is not modifying regulations promulgated under section 
608 of the Clean Air Act (CAA). EPA notes that there are additional 
requirements that concern the sale or offer for sale of refrigerants, 
including a sales restriction under the regulations implementing CAA 
section 608, which can be found at 40 CFR part 82 subpart F. These 
regulations collectively comprise the national recycling and emissions 
reduction program and may be commonly referred to as the stationary 
refrigeration and air conditioning management program. The general 
sales restriction provisions are codified at 40 CFR 82.154(c) and the 
specifications for self-sealing valves relevant to an exemption to the 
sales restriction for small cans of MVAC refrigerant are codified at 40 
CFR 82.154(c)(2). This action does not modify the provisions under 40 
CFR 82.154, including the restriction on the sale of substitute 
refrigerants and requirements for self-sealing valves.

B. SNAP Program Background

    The SNAP program implements CAA section 612. Several major 
provisions of section 612 are:
1. Rulemaking
    Section 612 requires EPA to promulgate rules making it unlawful to 
replace any class I (chlorofluorocarbon (CFC), halon, carbon 
tetrachloride, methyl chloroform, methyl bromide fluorocarbon, and 
chlorobromomethane) or class II (hydrochlorofluorocarbon (HCFC)) ozone-
depleting substances (ODS) with any substitute that the Administrator 
determines may present adverse effects to human health or the 
environment where the Administrator has identified an alternative that 
(1) reduces the overall risk to human health and the environment and 
(2) is currently or potentially available.

2. Listing of Unacceptable/Acceptable Substitutes

    Section 612(c) requires EPA to publish a list of the substitutes 
that it finds to be unacceptable for specific uses and to publish a 
corresponding list of acceptable substitutes for specific uses.
3. Petition Process
    Section 612(d) grants the right to any person to petition EPA to 
add a substance to, or delete a substance from, the lists published in 
accordance with section 612(c).
4. 90-Day Notification
    Section 612(e) directs EPA to require any person who produces a 
chemical substitute for a class I substance to notify the Agency not 
less than 90 days before a new or existing chemical is introduced into 
interstate commerce for significant new use as a substitute for a class 
I substance.\5\ The producer must

[[Page 26278]]

also provide the Agency with the producer's unpublished health and 
safety studies on such substitutes.
---------------------------------------------------------------------------

    \5\ EPA's SNAP regulations at 40 CFR 82.176 extend this 
requirement to substitutes for class II substances, providing that 
``[a]ny producer of a new substitute must submit a notice of intent 
to introduce a substitute into interstate commerce 90 days prior to 
such introduction.''
---------------------------------------------------------------------------

    The regulations for the SNAP program are promulgated at 40 CFR part 
82, subpart G, and the Agency's process for reviewing SNAP submissions 
is described in regulations at 40 CFR 82.180. Under these rules, the 
Agency has identified five types of listing decisions: Acceptable; 
acceptable subject to use conditions; acceptable subject to narrowed 
use limits; unacceptable; and pending (40 CFR 82.180(b)). Use 
conditions and narrowed use limits are both considered ``use 
restrictions,'' as described below. Substitutes that are deemed 
acceptable with no use restrictions (no use conditions or narrowed use 
limits) can be used for all applications within the relevant end-uses 
in the sector. After reviewing a substitute, the Agency may determine 
that a substitute is acceptable only if certain conditions in the way 
that the substitute is used are met to minimize risks to human health 
and the environment. EPA describes such substitutes as ``acceptable 
subject to use conditions.'' (40 CFR 82.180(b)(2)). For some 
substitutes, the Agency may permit a narrowed range of use within an 
end-use or sector. For example, the Agency may limit the use of a 
substitute to certain end-uses or specific applications within an 
industry sector. EPA describes these substitutes as ``acceptable 
subject to narrowed use limits.'' Under the narrowed use limit, users 
intending to adopt these substitutes ``must ascertain that other 
alternatives are not technically feasible.'' (40 CFR 82.180(b)(3)).
    In making decisions regarding whether a substitute is acceptable or 
unacceptable, and whether substitutes present risks that are lower than 
or comparable to risks from other substitutes that are currently or 
potentially available in the end-uses under consideration, EPA examines 
the criteria in 40 CFR 82.180(a)(7): (i) Atmospheric effects and 
related health and environmental impacts; (ii) general population risks 
from ambient exposure to compounds with direct toxicity and to 
increased ground-level ozone; (iii) ecosystem risks; (iv) occupational 
risks; (v) consumer risks; (vi) flammability; and (vii) cost and 
availability of the substitute.
    Many SNAP listings include ``comments'' or ``further information'' 
to provide additional information on substitutes. Since this additional 
information is not part of the regulatory decision, these statements 
are not binding for use of the substitute under the SNAP program. 
However, regulatory requirements so listed are binding as applicable 
under other regulatory programs (e.g., worker protection regulations 
promulgated by the U.S. Occupational Safety and Health Administration 
(OSHA)). The ``further information'' classification does not 
necessarily include all other legal obligations pertaining to the use 
of the substitute. While the items listed are not legally binding under 
the SNAP program, EPA encourages users of substitutes to apply all 
statements in the ``further information'' column in their use of these 
substitutes. In many instances, the information simply refers to sound 
operating practices that have already been identified in existing 
industry and/or building codes or standards. Thus, many of the 
statements, if adopted, would not require the affected user to make 
significant changes in existing operating practices.
    For additional information on the SNAP program, visit the SNAP 
portion of EPA's Ozone Layer Protection website at https://www.epa.gov/snap. Copies of the full lists of acceptable substitutes for ODS in all 
industrial sectors are available at https://www.epa.gov/snap/snap-substitutes-sector. For more information on the Agency's process for 
administering the SNAP program or criteria for evaluation of 
substitutes, refer to the initial SNAP rulemaking published March 18, 
1994 (59 FR 13044), codified at 40 CFR part 82, subpart G. SNAP 
decisions and the appropriate Federal Register citations are found at: 
https://www.epa.gov/snap/snap-regulations. Substitutes listed as 
unacceptable; acceptable, subject to narrowed use limits; or 
acceptable, subject to use conditions, are also listed in the 
appendices to 40 CFR part 82, subpart G.
    In this action, EPA refers to listings made in a final rule issued 
on December 1, 2016, at 81 FR 86778 (``2016 Rule'') in which the Agency 
listed HFO-1234yf as acceptable, subject to use conditions, in new 
MDPV, HD pickup trucks, and complete HD vans. The 2016 Rule also 
changed the listings for certain hydrofluorocarbons (HFCs) and blends 
from acceptable to unacceptable in various end-uses in the 
refrigeration and air conditioning, foam blowing, and fire suppression 
sectors. After a challenge to the 2016 Rule, the United States Court of 
Appeals for the District of Columbia Circuit (``the court'') issued a 
partial vacatur of the 2016 Rule ``only to the extent it requires 
manufacturers to replace HFCs that were previously and lawfully 
installed as substitutes for ozone-depleting substances.'' \6\ The 
court's decision on the 2016 Rule did not vacate the listing of HFO-
1234yf for certain types of vehicles, and this final rule is not EPA's 
response to the court's decision on the 2016 Rule.
---------------------------------------------------------------------------

    \6\ Mexichem Fluor, Inc. v. EPA, No. 17-1024, 760 Fed. Appx. 6, 
9 (D.C. Cir., April 5, 2019).
---------------------------------------------------------------------------

C. Does this action apply to me?

    The following list identifies types of regulated entities that may 
be affected by this action and their respective North American 
Industrial Classification System (NAICS) codes:
     All Other Basic Organic Chemical Manufacturing (NAICS 
325199)
     All Other General Merchandise Stores (NAICS 452990)
     All Other Miscellaneous Chemical Product and Preparation 
Manufacturing (NAICS 325998)
     Automotive Parts and Accessories Stores (NAICS 441310)
     Automotive Repair Shops Not Elsewhere Classified, 
Including Air Conditioning and Radiator Specialty Shops (NAICS 811198)
     Gasoline Stations with Convenience Stores (NAICS 447110)
     General automotive repair shops (NAICS 811111)
     Heavy Duty Truck Manufacturing (NAICS 336120)
     Industrial Gas Manufacturing (NAICS 32512)
     Motor Vehicle Body Manufacturing (NAICS 336211)
     Motor Vehicle Parts Manufacturing (NAICS 3363)
     Other Automotive Repair and Maintenance (NAICS 81119)
     Other Motor Vehicle Parts Manufacturing (NAICS 336390)
     Recyclable Material Merchant Wholesalers (NAICS 423930)
     Refrigeration Equipment and Supplies Merchant Wholesalers 
(NAICS 423740)
    This list is not intended to be exhaustive but provides a guide for 
readers regarding types of entities likely to be regulated by this 
action. This list includes the types of entities that EPA is now aware 
could potentially be regulated by this action. Other types of entities 
not listed above could also be regulated. To determine whether your 
facility, company, business, or organization could be affected by this 
action, you should carefully examine the regulations at 40 CFR part 82, 
subpart G. If you have questions regarding the applicability of this 
action to a particular entity, consult the person listed in the FOR 
FURTHER INFORMATION CONTACT section.

[[Page 26279]]

D. What acronyms and abbreviations are used in the preamble?

    Below is a list of acronyms and abbreviations used in the preamble 
of this document:

AIHA--American Industrial Hygiene Association
AC--Air Conditioning
ACH--Air Changes Per Hour
AEM--Association of Equipment Manufacturers
ANSI--American National Standards Institute
ASHRAE--American Society of Heating, Refrigerating and Air-
Conditioning Engineers
ASTM--American Society for Testing and Materials
ATEL--Acute Toxicity Exposure Limit
CAA--Clean Air Act
CAS Reg. No.--Chemical Abstracts Service Registry Identification 
Number
CBI--Confidential Business Information
CFC--Chlorofluorocarbon
CFD--Computational Fluid Dynamics
CFR--Code of Federal Regulations
CGA--Compressed Gas Association
CO2--Carbon Dioxide
CRP--Cooperative Research Project
DIY--Do-It-Yourself
E.O.--Executive Order
EPA--United States Environmental Protection Agency
FCL--Flammability Concentration Limit
FMEA--Failure Mode and Effects Analysis
FR--Federal Register
GHG--Greenhouse Gas
GWP--Global Warming Potential
GVWR--Gross Vehicle Weight Rating
HCFC--Hydrochlorofluorocarbon
HD--Heavy-Duty
HD GHG--Heavy-Duty Greenhouse Gas
HF--Hydrogen Fluoride
HFC--Hydrofluorocarbon
HFO--Hydrofluoroolefin
HP--Horsepower
ICF--ICF International, Inc.
IPCC--Intergovernmental Panel on Climate Change
LD--Light-Duty
LD GHG--Light-Duty Greenhouse Gas
LFL--Lower Flammability Limit
MDPV--Medium-Duty Passenger Vehicle
MVAC--Motor Vehicle Air Conditioning
MY--Model Year
NAAQS--National Ambient Air Quality Standards
NAICS--North American Industrial Classification System
NOAEL--No Observed Adverse Effect Level
NRC--National Research Council
OEM--Original Equipment Manufacturer
ODP--Ozone Depletion Potential
ODS--Ozone-depleting Substance
OMB--Office of Management and Budget
OSHA--Occupational Safety and Health Administration
PPE--Personal Protective Equipment
ppm--Parts Per Million
PRA--Paperwork Reduction Act
RCL--Reference Concentration Limit
RFA--Regulatory Flexibility Act
SAE--SAE International
SDS--Safety Data Sheet
SIP--State Implementation Plan
SNAP--Significant New Alternatives Policy
SNUN--Significant New Use Notice
SNUR--Significant New Use Rule
STEL--Short-term Exposure Limit
TFA--Trifluoroacetic Acid
TLV--Threshold Limit Value
TSCA--Toxic Substances Control Act
TWA--Time Weighted Average
UFL--Upper Flammability Limit
UMRA--Unfunded Mandates Reform Act
USGCRP--U.S. Global Change Research Program
VOC--Volatile Organic Compounds
WEEL--Workplace Environmental Exposure Limit

II. What is EPA finalizing in this action?

A. Listing of HFO-1234yf as Acceptable, Subject to use Conditions, for 
MVAC Systems in Certain new Nonroad Vehicles

    As proposed, (86 FR at 68968; December 6, 2021), EPA is listing 
HFO-1234yf as acceptable, subject to use conditions, for MVAC systems 
in several types of new nonroad vehicles, specifically: Agricultural 
tractors greater than 40 HP; self-propelled agricultural machinery; 
compact equipment; construction, forestry, and mining equipment; and 
commercial utility vehicles. All MVAC refrigerants listed as acceptable 
are subject to use conditions requiring labeling and the use of unique 
fittings as described in Appendix B to subpart G of part 82--
Substitutes Subject to Use Restrictions and Unacceptable Substitutes. 
EPA is listing HFO-1234yf as acceptable, subject to use conditions, in 
the five nonroad vehicle types. The use conditions require that MVAC 
systems designed to use HFO-1234yf meet the requirements of SAE J639, 
SAE J1739, and SAE J2844 to help ensure that use of HFO-1234yf does not 
have a significantly greater overall impact on human health and the 
environment than other alternatives for use in those vehicles. EPA is 
updating the existing use conditions that are currently required for 
the use of HFO-1234yf in MVAC systems in new LD vehicles, MDPVs, HD 
pickup trucks, and complete HD vans and applying them to all the MVAC 
systems addressed in this action. The use conditions are detailed below 
in section II.A.4, ``What are the use conditions?''
1. What is the affected end-use?
    Under SNAP, MVAC systems cool the passenger compartment of LD 
passenger vehicles and trucks, HD vehicles (e.g., large pickups, 
delivery trucks, and semi-trucks), off[hyphen]road vehicles, buses, and 
passenger rail vehicles. These systems are typically charged during 
vehicle manufacture, and the main components are connected by flexible 
refrigerant lines. Nonroad vehicles can be grouped into several 
categories (i.e., agriculture, construction, recreation, and many other 
purposes).\7\ The vehicle types addressed in this action include 
certain types of new nonroad vehicles, specifically:
---------------------------------------------------------------------------

    \7\ EPA, 2021. Basic Information about the Emission Standards 
Reference Guide for On-road and Nonroad Vehicles and Engines. 
Available online at https://www.epa.gov/emission-standards-reference-guide/basic-information-about-emission-standards-reference-guide-road and in the docket for this rulemaking at 
https://nepis.epa.gov/Exe/ZyPDF.cgi/P100K5U2.PDF?Dockey=P100K5U2.PDF.
---------------------------------------------------------------------------

     Agricultural tractors greater than 40 HP (including two-
wheel drive (2WD), mechanical front-wheel drive (MFD), four-wheel drive 
(4WD), and track tractors) that are used for a number of agricultural 
applications such as farm work, planting, landscaping, and loading; 
8 9
---------------------------------------------------------------------------

    \8\ Wagner, 2021. May 24, 2021, email from John Wagner of the 
Association of Equipment Manufacturers to EPA. Available in the 
docket for this rulemaking.
    \9\ AEM, 2021. Appendix A: Machine Forms as Classified by AEM 
Membership. Available in the docket for this rulemaking.
---------------------------------------------------------------------------

     Self-propelled agricultural machinery (including combines, 
grain and corn harvesters, sprayers, windrowers, and floaters) that are 
primarily used for harvesting, fertilizer, and herbicide operations; 
\10\
---------------------------------------------------------------------------

    \10\ Ibid.
---------------------------------------------------------------------------

     Compact equipment (including mini excavators, turf mowers, 
skid-steer loaders, and tractors less than 40 HP) that are primarily 
used for agricultural operations and residential, commercial, and 
agricultural landscaping; \11\
---------------------------------------------------------------------------

    \11\ Ibid.
---------------------------------------------------------------------------

     Construction, forestry, and mining equipment (including 
excavators, bulldozers, wheel loaders, feller bunchers, log skidders, 
road graders, articulated trucks, sub-surface machines, horizontal 
directional drill, trenchers, and tracked crawlers) that are primarily 
used to excavate surface and subsurface materials during construction, 
landscaping, and road maintenance and building; \12\ and
---------------------------------------------------------------------------

    \12\ Ibid.
---------------------------------------------------------------------------

     Commercial utility vehicles that are primarily used for 
ranching, farming, hunting/fishing, construction, landscaping, property 
maintenance, railroad maintenance, forestry, and mining.\13\
---------------------------------------------------------------------------

    \13\ Ibid.
---------------------------------------------------------------------------

    These nonroad vehicles are almost exclusively used and operated by 
professionals (e.g., agricultural owners or skilled employees/
operators) and vary by size, weight, use, and/or

[[Page 26280]]

horsepower.\14\ For example, commercial utility vehicles typically 
weigh between 1,200 and 2,400 pounds, while agricultural tractors >40 
HP typically weigh between 39,000 and 50,000 pounds.15 16 
MVAC systems in these nonroad vehicles can have charge sizes ranging 
from 650 grams (23 ounces) to 3,400 grams (120 ounces) depending on the 
manufacturer and cab size, compared to a range of 390 grams (14 ounces) 
to 1,600 grams (56 ounces) for MVAC systems in light and medium duty 
passenger vehicles, HD pickups, and complete HD vans.\17\ Additionally, 
unlike onroad passenger vehicles, for example, nonroad vehicles are 
limited to non-highway terrain (e.g., fields, construction sites, 
forests, and mines), have more robust components, are operated at low 
working speeds, and there are typically a limited number of vehicles in 
the same location.
---------------------------------------------------------------------------

    \14\ EPA, 2021. Basic Information about the Emission Standards 
Reference Guide for On-road and Nonroad Vehicles and Engines. 
Available online at https://www.epa.gov/emission-standards-reference-guide/basic-information-about-emission-standards-reference-guide-road and in the docket for this rulemaking.
    \15\ Heavy-duty vehicles are often subdivided by vehicle weight 
classifications, as defined by the vehicle's gross vehicle weight 
rating (GVWR), which is a measure of the combined curb (empty) 
weight and cargo carrying capacity of the truck. Heavy-duty vehicles 
have GVWRs above 8,500. See https://www.epa.gov/emission-standards-reference-guide/vehicle-weight-classifications-emission-standards-reference-guide.
    \16\ Wagner, 2021. May 24, 2021, email from John Wagner of the 
Association of Equipment Manufacturers to EPA. Available in the 
docket for this rulemaking.
    \17\ ICF, 2016. Technical Support Document for Acceptability 
Listing of HFO-1234yf for Motor Vehicle Air Conditioning in Limited 
Heavy-Duty Applications. Available in the public docket for this 
rulemaking.
---------------------------------------------------------------------------

2. What are the ANSI/ASHRAE classifications for refrigerant 
flammability?
    The American National Standards Institute/American Society of 
Heating, Refrigerating and Air Conditioning Engineers (ANSI/ASHRAE) 
Standard 34-2019 assigns a safety group classification for each 
refrigerant which consists of two to three alphanumeric characters 
(e.g., A2L or B1). The initial capital letter indicates the toxicity, 
and the numeral denotes the flammability. ASHRAE classifies Class A 
refrigerants as refrigerants for which toxicity has not been identified 
at concentrations less than or equal to 400 ppm by volume, based on 
data used to determine threshold limit value-time-weighted average 
(TLV-TWA) or consistent indices. Class B signifies refrigerants for 
which there is evidence of toxicity at concentrations below 400 ppm by 
volume, based on data used to determine TLV-TWA or consistent indices.
    Refrigerants are also assigned a flammability classification of 1, 
2, 2L, or 3. Tests for flammability are conducted in accordance with 
American Society for Testing and Materials (ASTM) E681 using a spark 
ignition source at 140 [deg]F (60 [deg]C) and 14.7 psia (101.3 kPa) 
\18\ . The flammability classification ``1'' is given to refrigerants 
that, when tested, show no flame propagation. The flammability 
classification ``2'' is given to refrigerants that, when tested, 
exhibit flame propagation, have a heat of combustion less than 19,000 
kJ/kg (8,169 Btu/lb.), and have a lower flammability limit (LFL) 
greater than 0.10 kg/m\3\. The flammability classification ``2L'' is 
given to refrigerants that, when tested, exhibit flame propagation, 
have a heat of combustion less than 19,000 kJ/kg (8,169 BTU/lb.), have 
an LFL greater than 0.10 kg/m\3\, and have a maximum burning velocity 
of 10 cm/s or lower when tested in dry air at 73.4 [deg]F (23.0 [deg]C) 
and 14.7 psia (101.3 kPa). The flammability classification ``3'' is 
given to refrigerants that, when tested, exhibit flame propagation and 
that either have a heat of combustion of 19,000 kJ/kg (8,169 BTU/lb.) 
or greater or have an LFL of 0.10 kg/m\3\ or lower. Using these safety 
group classifications, ANSI/ASHRAE Standard 34-2019 categorizes HFO-
1234yf in the A2L Safety Group.
---------------------------------------------------------------------------

    \18\ ASHRAE, 2019. ANSI/ASHRAE Standard 34-2019: Designation and 
Safety Classification of Refrigerants.
[GRAPHIC] [TIFF OMITTED] TR04MY22.001

3. How does HFO-1234yf compare to other refrigerants for these MVAC 
applications with respect to SNAP criteria?
    When reviewing a substitute under SNAP, EPA compares the risk posed 
by that substitute to the risks posed by other alternatives and 
considers whether that specific substitute under review poses 
significantly more risk than other available or potentially available 
alternatives for the same use. In the proposed rule (86 FR 68962; 
December 6, 2021), EPA provided information on the environmental and 
health properties of HFO-1234yf and other substitutes in these MVAC 
applications and described the Agency's comparative risk analysis, 
based on our criteria for review, including an

[[Page 26281]]

evaluation of environmental impacts, flammability, and toxicity. 
Redacted submissions that do not include information claimed as CBI by 
the submitter and supporting documentation for HFO-1234yf are provided 
in the docket for this rulemaking (EPA-HQ-OAR-2021-0347 at https://www.regulations.gov). EPA's assessments to examine the health and 
environmental risks of HFO-1234yf in each equipment type are also 
available in the docket for this rulemaking.19 20 21 22 23
---------------------------------------------------------------------------

    \19\ ICF, 2021a. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Agricultural Tractors Greater than 
40 Horsepower) (New Equipment).
    \20\ ICF, 2021b. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Self-Propelled Agricultural 
Machinery) (New Equipment).
    \21\ ICF, 2021c. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Compact Equipment) (New Equipment).
    \22\ ICF, 2021d. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Construction, Forestry, and Mining 
Equipment) (New Equipment).
    \23\ ICF, 2021e. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Commercial Utility Vehicles) (New 
Equipment).
---------------------------------------------------------------------------

    As explained more fully below, to help evaluate environmental, 
flammability, and toxicity risks resulting from the use of HFO-1234yf 
in certain types of new nonroad vehicles, EPA considered the Agency's 
analyses 24 25 26 27 28 29 30 31 32 conducted in support of 
the 2011 (76 FR 17488; March 29, 2011) and 2016 (81 FR 86778; December 
1, 2016) listing decisions for HFO-1234yf in MVAC systems, including 
information submitted during the public comment period of the proposal 
for the 2011 final decision (October 19, 2009; 74 FR 53445), such as 
the SAE Cooperative Research Project's (CRP) risk 
assessments.33 34 35 36 37 These risk assessments are 
available in the docket for this rulemaking. The refrigerants to which 
HFO-1234yf was compared in the 2011 action for LD vehicles are the same 
refrigerants available for use in the nonroad vehicle types included in 
this action. In addition, EPA considered risk assessments 
38 39 40 41 42 conducted by the Association of Equipment 
Manufacturers (AEM), an industry consortium of construction and 
agriculture equipment manufacturers, and found these were consistent 
with the Agency's assessments to examine the health and environmental 
risks of HFO-1234yf in each vehicle type.
---------------------------------------------------------------------------

    \24\ EPA, 2005. Risk Analysis for Alternative Refrigerant in 
Motor Vehicle Air Conditioning.
    \25\ ICF, 2008a. Air Conditioning Refrigerant Charge Size to 
Passenger Compartment Volume Ratio Analysis.
    \26\ ICF, 2008b. Revised Characterization of U.S. Hybrid and 
Small Car Sales (Historical and Predicted) and Hybrid Vehicle 
Accidents.
    \27\ ICF, 2009a. Revised Final Draft Assessment of the Potential 
Impacts of HFO-1234yf and the Associated Production of TFA on 
Aquatic Communities and Local Air Quality.
    \28\ ICF, 2009b. Risk Screen on Substitutes for CFC-12 in Motor 
Vehicle Air Conditioning: Substitute: HFO-1234yf.
    \29\ ICF, 2010a. Summary of HFO-1234yf Emissions Assumptions.
    \30\ ICF, 2010b. Summary of Updates to the Vintaging Model that 
Impacted HFO-1234yf Emissions Estimates.
    \31\ ICF, 2010c. Revised Assessment of the Potential Impacts of 
HFO-1234yf and the Associated Production of TFA on Aquatic 
Communities, Soil and Plants, and Local Air Quality.
    \32\ ICF, 2010d. Sensitivity Analysis CMAQ results on projected 
maximum TFA rainwater concentrations and maximum 8-hr ozone 
concentrations.
    \33\ CRP, 2008. Risk Assessment for Alternative Refrigerants 
HFO-1234yf Phase II. Prepared for SAE International Cooperative 
Research Program 1234 by Gradient Corporation.
    \34\ CRP, 2009. Risk Assessment for Alternative Refrigerants 
HFO-1234yf and R-744 (CO2) Phase III. Prepared for SAE 
International Cooperative Research Program 1234 by Gradient 
Corporation.
    \35\ DuPont and Honeywell. Guidelines for Use and Handling of 
HFO-1234yf (v8.0).
    \36\ Exponent. 2008. HFO-1234yf Refrigerant Concentration and 
Ignition Tests in Full-Scale Vehicle Passenger Cabin and Engine 
Compartment.
    \37\ CRP, 2013.SAE International Cooperative Research Project 
CRP1234-4 on R-1234yf Safety, Finishes Work and Presents 
Conclusions. Available online at: http://www.sae.org/servlets/pressRoom?OBJECT_TYPE=PressReleases&PAGE=showRelease&RELEASE_ID=2146.

    \38\ AEM, 2019. Risk Assessment for HFO-1234yf in Agricultural 
Tractors >= 40 HP including 2WD, MFD, 4WD and Track Type Equipment.
    \39\ AEM, 2020a. Risk Assessment for HFO-1234yf in Self-
Propelled Agricultural Machinery including Combines, Forage 
Harvesters, Sprayers, and Windrowers.
    \40\ AEM, 2020b. Risk Assessment for HFO-1234yf in Compact 
Equipment (Examples include Tractors <40HP, Turf Equipment, Skid 
Steer, Mini-Excavators and Track Loaders)
    \41\ AEM, 2020c. Risk Assessment for HFO-1234yf in Construction, 
Forestry and Mining Equipment.
    \42\ AEM, 2020d. Risk Assessment for HFO-1234yf in Commericial 
Utility Vehicles.
---------------------------------------------------------------------------

a. Environmental Impacts
    The SNAP program considers a number of environmental criteria when 
evaluating substitutes: Ozone depleting potential (ODP); climate 
effects, primarily based on global warming potential (GWP); local air 
quality impacts, particularly potential impacts on smog formation from 
emissions of volatile organic compounds (VOC); and ecosystem effects, 
particularly from negative impacts on aquatic life. These and other 
environmental and health risks are discussed below.
    HFO-1234yf is chemical substance identified as 2,3,3,3-
tetrafluoroprop-1-ene (CAS Reg. No. 754-12-1). HFO-1234yf has a GWP of 
four, 43 44 which is similar to or lower than the GWP of 
other alternatives for the nonroad vehicles addressed in this final 
rule. For example, its GWP is significantly lower than that of HFC-
134a, the refrigerant most widely used in these vehicles today, which 
has a GWP of 1,430. As shown in Table 1, two other alternatives, HFC-
152a \45\ and CO2,\46\ have GWPs of 124 and 1, respectively.
---------------------------------------------------------------------------

    \43\ Nielsen et al., 2007. Atmospheric chemistry of CF3CF=CH2: 
Kinetics and mechanisms of gas-phase reactions with Cl atoms, OH 
radicals, and O3. Chemical Physics Letters 439, 18-22. Available 
online at: http://www.cogci.dk/network/OJN_174_CF3CF=CH2.pdf.
    \44\ Papadimitriou et al., 2007. CF3CF=CH2 and (Z)-CF3CF=CHF: 
temperature dependent OH rate coefficients and global warming 
potentials. Phys. Chem. Chem. Phys., 2007, Vol. 9, p. 1-13. 
Available online at: http://pubs.rsc.org/en/Content/ArticleLanding/2008/CP/b714382f.
    \45\ HFC-152a is listed as acceptable, subject to use 
conditions, for new vehicles only at 40 CFR part 82 subpart G; final 
rule published June 12, 2008 (73 FR 33304).
    \46\ CO2 is listed as acceptable, subject to use 
conditions, for new vehicles only at 40 CFR part 82 subpart G; final 
rule published June 6, 2012 (77 FR 33315).
---------------------------------------------------------------------------

    Other acceptable refrigerants for the nonroad vehicles addressed in 
this action have GWPs ranging from 933 to 3,337. These include several 
blend refrigerants that are listed as acceptable, subject to use 
conditions, for these nonroad vehicles, including the HFC blends SP34E 
and R-426A (also known as RS-24) and the HCFC blends R-416A (also known 
as HCFC Blend Beta or FRIGC FR12), R-406A, R-414A (also known as HCFC 
Blend Xi or GHG-X4), R-414B (also known as HCFC Blend Omicron), HCFC 
Blend Delta (also known as Free Zone), Freeze 12, GHG-X5, and HCFC 
Blend Lambda (also known as GHG-HP). In a final rule issued July 20, 
2015, at 80 FR 42870 (``2015 Rule''),\47\ EPA listed the use of certain 
refrigerant blends, including the ones mentioned above, as unacceptable 
in new LD vehicles starting in MY 2017. EPA did not propose and is not 
finalizing a change of status for use of these refrigerant blends in 
MVACs in nonroad vehicles. Although EPA is not aware of the use of 
these refrigerant blends, they remain acceptable, subject to use 
conditions, for the nonroad vehicles addressed in this action. Also,

[[Page 26282]]

although they are listed as acceptable, subject to use conditions, EPA 
is not aware of the use or development of HFC-152a, CO2, or 
any of the refrigerant blends above in new nonroad vehicles.\48\ 
Additionally, all MVAC refrigerants are subject to use conditions 
requiring labeling and the use of unique fittings, and the two lower-
GWP alternatives currently approved for use in nonroad vehicles (i.e., 
HFC-152a and CO2) are subject to additional use conditions 
mitigating flammability and toxicity as appropriate to the alternative.
---------------------------------------------------------------------------

    \47\ The 2015 Rule, among other things, changed the listings for 
certain HFCs and blends from acceptable to unacceptable in various 
end-uses in the aerosols, refrigeration and air conditioning, and 
foam blowing sectors. After a challenge to the 2015 Rule, the United 
States Court of Appeals for the District of Columbia Circuit (``the 
court'') issued a partial vacatur of the 2015 Rule ``to the extent 
it requires manufacturers to replace HFCs with a substitute 
substance'' (see Mexichem Fluor, Inc. v. EPA, 866 F.3d 451, 462 
(D.C. Cir. 2017) and remanded the rule to the Agency for further 
proceedings. The court also upheld EPA's listing changes as being 
reasonable and not ``arbitrary and capricious.'' See Mexichem Fluor, 
866 F.3d at 462-63.
    \48\ The CAA and EPA's ODS regulations restrict the permissible 
uses of virgin HCFCs. With respect to refrigerants, virgin HCFC-22, 
HCFC-142b and blends containing HCFC-22 or HCFC-142b may now only be 
used to service existing appliances. Consequently, virgin HCFC-22, 
HCFC-142b and blends containing virgin HCFC-22 or HCFC-142b may no 
longer be used as a refrigerant to manufacture new pre-charged 
appliances or appliance components or to charge new appliances 
assembled onsite.

    Table 1: GWP, ODP, and VOC Status of HFO-1234yf Compared to Other Refrigerants in MVAC Systems of Nonroad
                                                  Vehicles \1\
----------------------------------------------------------------------------------------------------------------
           Refrigerants                   GWP             ODP             VOC status           Final decision
----------------------------------------------------------------------------------------------------------------
HFO-1234yf........................               4               0  No...................  Acceptable, subject
                                                                                            to use conditions.
CO2, HFC-152a, HFC-134a...........         1-1,430               0  No...................  No change.
Other refrigerants, including IKON       933-3,337         0-0.098  Yes \2\..............  No change.
 A, R-414B, R-416A, R-426A, SP34E.
----------------------------------------------------------------------------------------------------------------
\1\ The table does not include not-in-kind technologies listed as acceptable for the stated end-use.
\2\ One or more constituents of the blend are VOC.

    HFO-1234yf does not deplete the ozone layer. Similarly, HFC-134a, 
HFC-152a, CO2, and the HFC blends SP34E and R-426A do not 
deplete the ozone layer; however, the HCFC blends have ODPs ranging 
from 0.012 to 0.056.
    HFO-1234yf, HFC-134a, HFC-152a, and CO2 are exempt from 
the EPA's regulatory definition of VOC (see 40 CFR 51.100(s)) 
addressing the development of state implementation plans (SIPs) to 
attain and maintain the National Ambient Air Quality Standards (NAAQS). 
The HFC blends and some of the HCFC blends have one or more components 
that are VOC.
    Another potential environmental impact of HFO-1234yf is its 
atmospheric decomposition to trifluoroacetic acid (TFA, 
CF3COOH). TFA is a strong acid that may accumulate in soil, 
plants, and aquatic ecosystems over time and may have the potential to 
adversely impact plants, animals, and ecosystems.\49\ For information 
on recent analyses and research that has been conducted on TFA, 
including EPA's 2011 analysis, which was based on conservative 
emissions assumptions and a transition from HFC-134a to HFO-1234yf for 
all MVAC systems (not limited to LD vehicles), see section II.A.3.a of 
the proposed rule (86 FR at 68968; December 6, 2021). Taking into 
consideration the 2011 analysis and the research that has been 
conducted since, as discussed in section II.A.3.a in the proposed rule, 
EPA concludes that the use of HFO-1234yf in the nonroad vehicles 
addressed in this action does not pose a significant risk to the 
environment from atmospheric decomposition to TFA.
---------------------------------------------------------------------------

    \49\ Other fluorinated compounds also decompose into TFA, 
including HFC-134a.
---------------------------------------------------------------------------

    Therefore, based on the consideration of all of these environmental 
impacts, EPA concludes that HFO-1234yf does not pose significantly 
greater risk to the environment than the other alternatives for use in 
new nonroad vehicles addressed in this action, and it poses 
significantly less risk than several of the alternatives with higher 
GWPs and ODPs.
b. Flammability
    HFO-1234yf is a flammable refrigerant classified as A2L under 
ASHRAE 34-2013. HFC-134a, CO2, and the refrigerant blends 
SP34E and R-426A (also known as RS-24) and the HCFC blends R-416A (also 
known as HCFC Blend Beta or FRIGC FR12), R-414A (also known as HCFC 
Blend Xi or GHG-X4), R-414B (also known as HCFC Blend Omicron), HCFC 
Blend Delta (also known as Free Zone), Freeze 12, GHG-X5, and HCFC 
Blend Lambda (also known as GHG-HP) are nonflammable refrigerants, 
while HFC-152a and R-406A are slightly more flammable than HFO-1234yf 
with an ASHRAE classification of A2. HFO-1234yf is flammable when its 
concentration in air is in the range of 6.2 percent to 12.3 percent by 
volume (62,000 ppm to 123,000 ppm).\50\ In the presence of an ignition 
source (e.g., static electricity, a spark resulting from a switch 
malfunction, or a cigarette), an explosion or a fire could occur when 
the concentration of HFO-1234yf exceeds its LFL of 62,000 ppm, posing a 
significant safety concern for workers and consumers if it is not 
handled carefully. However, HFO-1234yf is difficult to ignite and, in 
the event of ignition, the flames would propagate slowly.\51\
---------------------------------------------------------------------------

    \50\ Chemours, 2019. HFO-1234yf for Use as a Refrigerant. 
Significant New Alternatives Policy Program Submission to the U.S. 
Environmental Protection Agency.
    \51\ HFO-1234yf has a high minimum ignition energy of 5,000-
10,000 mJ and a low burning velocity of 1.5 cm/s (Koban, 2011).
---------------------------------------------------------------------------

    With regards to flammability risks to workers, EPA's risk screens 
evaluated the potential for a fire from release and ignition in 
workplace situations and work-site operations, such as during equipment 
manufacture, servicing and disposal or recycling of vehicle end-of-life 
for the five nonroad vehicles. EPA considered the characteristics that 
could be different from LD and other HD vehicles, such as differences 
in the engine compartment size, passenger cabins, and operating 
conditions, and how those might impact risks. In order to determine the 
potential flammability risks during servicing of the vehicle or in case 
of a release of refrigerant into the cab, concentrations of HFO-1234yf 
immediately following a 60 percent release of refrigerant over a period 
of one minute into the cab were compared to the LFL and upper 
flammability limit (UFL) for HFO-1234yf reported by ASHRAE Standard 34 
(i.e., 62,000 ppm and 123,000 ppm, respectively). The one-minute time 
duration is most appropriate for determining the risks of flammable 
refrigerants because the potential maximum instantaneous concentration 
can be estimated and compared to the LFL. Two key inputs to the models 
were the cab volume (i.e., the space into which the refrigerant would 
leak) and the refrigerant charge size. Because passenger compartment 
volumes and refrigerant charge sizes can vary widely from model to 
model, the highest ratio of charge size to

[[Page 26283]]

compartment volume identified was used as the input into the models.
    In the event of a leak, SAE Standard J2772 specifies that nonroad 
vehicles be manufactured such that the pressure differential between 
the air conditioning system and the cab allows only up to 60 percent of 
the refrigerant charge to be released into the cab.\52\ Independent 
testing of refrigerant releases from nonroad vehicles, according to SAE 
Standard J2772, found that the amount of refrigerant released following 
a line leak was much lower than 60 percent.
---------------------------------------------------------------------------

    \52\ SAE, 2019. Standard J2772: Measurement of Passenger 
Compartment Refrigerant Concentrations Under System Refrigerant 
Leakage Conditions. SAE International.
---------------------------------------------------------------------------

    To represent a plausible worst-case scenario, EPA's box modeling 
assumed that 60 percent of the charge of the air conditioning systems 
for the five nonroad vehicles is released into the cab of the vehicles 
over a period of one minute. EPA's worst-case scenario box modeling 
resulted in the concentration of HFO-1234yf in the cab exceeding the 
LFL of 62,000 ppm by 2,100 ppm at the typical charge size (i.e., 1.3 
kilograms) and exceeding both the LFL (by 95,900 ppm) and the UFL (by 
34,900 ppm) at the maximum charge size (i.e., 3.2 kilograms), for the 
five nonroad vehicles. However, the estimated exposures were derived 
using conservative assumptions and represent worst-case scenarios with 
a low probability of occurrence, as the analyses assume a rapid release 
of refrigerant (i.e., one minute), assume the minimum required fresh 
air intake, and do not consider the air recirculation rate for the 
nonroad vehicles or other variables that would potentially reduce the 
concentration levels in the air to below the flammable range for HFO-
1234yf. Additionally, flammability concerns are further reduced due to 
the design of MVAC systems for the five vehicle types as described 
above in section II.A.1 and the low probability of collisions for these 
nonroad vehicles.
    MVAC systems in the nonroad vehicles are robust and made to 
withstand strenuous operation, which lowers the potential for line 
leaks due to wear. According to AEM, 53 54 55 56 57 the 
operator's compartment in agricultural tractors greater than 40 HP; 
self-propelled agricultural machinery; compact equipment; and 
construction, forestry, and mining equipment is a completely self-
contained unit which provides an additional level of safety in a 
collision event. For commercial utility vehicles, which are smaller 
than the other four nonroad vehicle types, AEM noted that the engine 
compartment is contained in the rear of the vehicle, under the cargo 
bed, with the main components of the MVAC system in the front of the 
cabin with only the compressor and two lines near the engine. The 
potential for collisions is also less likely because most of the 
vehicles are operated by trained professionals, typically at low speed, 
and are only driven on the highway to move from one site or nonroad 
location to another.
---------------------------------------------------------------------------

    \53\ AEM, 2019. Risk Assessment for HFO-1234yf in Agricultural 
Tractors >= 40 HP including 2WD, MFD, 4WD and Track Type Equipment.
    \54\ AEM, 2020a. Risk Assessment for HFO-1234yf in Self-
Propelled Agricultural Machinery including Combines, Forage 
Harvesters, Sprayers, and Windrowers.
    \55\ AEM, 2020b. Risk Assessment for HFO-1234yf in Compact 
Equipment (Examples include Tractors <40HP, Turf Equipment, Skid 
Steer, Mini-Excavators and Track Loaders).
    \56\ AEM, 2020c. Risk Assessment for HFO-1234yf in Construction, 
Forestry, and Mining Equipment.
    \57\ AEM, 2020d. Risk Assessment for HFO-1234yf in Commercial 
Utility Vehicles.
---------------------------------------------------------------------------

    In addition to the plausible worst-case scenario analysis, which 
employs a simple box model, EPA's risk screens reference modeling 
conducted by AEM in the flammability assessments. The AEM consortium 
used two different models in its assessments: (1) A box model to 
examine worst-case scenarios for a wide variety of nonroad vehicles 
addressed in this proposal and (2) a computational fluid dynamics (CFD) 
58 59 60 61 62 63 model to more realistically represent the 
behavior of the leaked refrigerant in an nonroad vehicle. The AEM box 
model modeled the release of 60 percent of the refrigerant charge in 
the vehicles with varying charge and cab sizes and assumed a near-
instantaneous leak of refrigerant over a period of 10 seconds. Six of 
the scenarios modeled in the box model resulted in the concentration of 
HFO-1234yf in the cab being equal to or exceeding the LFL; the 
concentrations from the remaining six scenarios were below the LFL. 
Similar to EPA's box modeling, the estimated exposures were derived 
using conservative assumptions and represent worst-case scenarios with 
a low probability of occurrence, as the analyses assume a rapid release 
of refrigerant, assume the minimum required fresh air intake (i.e., 43 
m\3\/hour), and do not consider the air recirculation rate for the 
nonroad vehicles or other variables that would potentially reduce the 
concentration levels in the air to below the flammable range for HFO-
1234yf.
---------------------------------------------------------------------------

    \58\ AEM, 2019. Risk Assessment for HFO-1234yf in Agricultural 
Tractors >= 40 HP including 2WD, MFD, 4WD and Track Type Equipment.
    \59\ AEM, 2020a. Risk Assessment for HFO-1234yf in Self-
Propelled Agricultural Machinery including Combines, Forage 
Harvesters, Sprayers, and Windrowers.
    \60\ AEM, 2020b. Risk Assessment for HFO-1234yf in Compact 
Equipment (Examples include Tractors <40HP, Turf Equipment, Skid 
Steer, Mini-Excavators and Track Loaders).
    \61\ AEM, 2020c. Risk Assessment for HFO-1234yf in Construction, 
Forestry, and Mining Equipment.
    \62\ AEM, 2020d. Risk Assessment for HFO-1234yf in Commercial 
Utility Vehicles.
    \63\ AEM, 2020e. CFD Leak Modeling-Supplemental Information to 
Compliment AEM Machine Form RAs.
---------------------------------------------------------------------------

    Conversely, the maximum concentration reached in the AEM CFD model, 
which models a realistic leak scenario with the release of 60 percent 
of the refrigerant charge released in the nonroad vehicles for 1000 
seconds of simulation, was significantly below the LFL for HFO-1234yf 
of 62,000 ppm. Construction, forestry, and mining vehicles were modeled 
to represent the five nonroad vehicles as they had the highest ratio of 
refrigerant charge to cabin volume among the five nonroad vehicles. AEM 
found that the maximum concentration of HFO-1234yf reached in the cab 
(i.e., 25,700 ppm) is not likely to exceed the LFL for the five nonroad 
vehicles. The AEM CFD model reflects the real-world behavior of 
refrigerant in the cab given a worst-case leak scenario because it 
considers the refrigerant entry and exit points and assumes worst-case 
scenario conditions, including the most likely scenario where an 
operator is likely to ignite a cigarette, the highest charge-to-cab 
ratio, minimal fresh air flow, and maximum air velocity and refrigerant 
penetration. Additionally, the CFD modeling demonstrates the 
conservativeness of the worst-case scenario box modeling and how 
unlikely its results are; therefore, the worst-case scenario box models 
may be overstating the true risks associated with the use of HFO-1234yf 
in MVAC systems in the nonroad vehicles compared to real-world 
conditions as presented in the CFD model.
    For these reasons, EPA concludes that the currently available 
assessments on the use of HFO-1234yf in new nonroad vehicles addressed 
in this action are sufficiently conservative to account for all 
probable flammability risks from the use of HFO-1234yf. Relying on a 
similar analysis considered in support of the 2011 and 2016 SNAP 
listings of HFO-1234yf in certain MVAC systems, verifying that more 
recent information is consistent with that analysis, and considering 
unique factors for the nonroad vehicle types, EPA concludes that the 
use of HFO-1234yf in the new nonroad vehicles addressed in this action 
does not pose significantly greater flammability risk than the other 
alternatives when used in accordance with the use conditions described 
below

[[Page 26284]]

in section II.A.4, which are intended to mitigate flammability risks, 
and recommendations in the safety data sheet (SDS) and EPA's risk 
screens.
c. Toxicity
    Potential health effects of exposure to HFO-1234yf include 
drowsiness or dizziness. HFO-1234yf may also irritate the skin or eyes 
or cause frostbite, and at sufficiently high concentrations, HFO-1234yf 
may cause irregular heartbeat. HFO-1234yf could cause asphyxiation if 
air is displaced by vapors in a confined space. These potential health 
effects are common to many refrigerants.
    The American Industrial Hygiene Association (AIHA) has established 
a Workplace Environmental Exposure Level (WEEL) of 500 ppm as an 8-hr 
TWA for HFO-1234yf. HFO-1234yf also has an acute toxicity exposure 
limit (ATEL) of 100,000 ppm and a refrigerant concentration limit (RCL) 
of 16,000 ppm, which are both established by ASHRAE. EPA anticipates 
that users will be able to meet the AIHA WEEL and ASHRAE ATEL and RCL, 
limits intended to reduce the risks of flammability in normally 
occupied, enclosed spaces, and address potential health risks by 
following requirements and recommendations in the manufacturer's SDSs 
and other safety precautions common to the refrigerant industry.
    To evaluate human health and safety impacts, including asphyxiation 
and toxicity risks, from the use of HFO-1234yf in the five types of 
nonroad vehicles, the Agency estimated the potential exposures to HFO-
1234yf in the event of a 60 percent release of refrigerant from the 
vehicles under reasonable worst-case scenarios described in the risk 
screens. In the event of a leak, SAE Standard J2772 specifies that 
nonroad vehicles be manufactured such that the pressure differential 
between the air conditioning system and the cab allows only up to 60 
percent of the refrigerant charge to be released into the cab.\64\ The 
analysis of asphyxiation risks considered whether a worst-case release 
of refrigerant under the cab would result in oxygen concentrations of 
12 percent or less. The analysis found that impacts on oxygen 
concentrations did not present a significant risk of asphyxiation at 
the typical charge sizes, and that a 60 percent leak of refrigerant at 
the maximum charge sizes could result in an oxygen concentration below 
19.5 percent but above 12 percent. The estimated exposures were derived 
using conservative assumptions, however, and conditions resulting in 
oxygen levels under 12 percent \65\ are only predicted to occur with 
charge sizes that are significantly larger than the maximum charge 
sizes provided by the submitter or cab sizes that are unlikely for the 
applications. Additionally, the worst-case scenarios did not consider 
conditions that are likely to occur that would increase oxygen levels 
to which individuals would be exposed, such as fresh air flow into the 
cab.
---------------------------------------------------------------------------

    \64\ SAE, 2019. Standard J2772: Measurement of Passenger 
Compartment Refrigerant Concentrations Under System Refrigerant 
Leakage Conditions. SAE International.
    \65\ Twelve percent oxygen in air (i.e., 120,000 ppm) is the No-
Observed-Adverse-Effect-Level (NOAEL) for hypoxia (ICF, 1997).
---------------------------------------------------------------------------

    To assess the toxicity risks to end-users, 15-minute and 30-minute 
TWA exposures were estimated and compared to the standard toxicity 
limits. The estimated TWA exposures were fairly conservative as the 
analyses assume a rapid release of refrigerant (i.e., one minute and 10 
seconds for EPA's and AEM's box models, respectively), assume the 
minimum required ventilation rate (i.e., 43 m\3\/hour), and do not 
consider the air recirculation rate for the vehicles or other variables 
that would potentially reduce the concentration levels in the air. EPA 
found that the estimated 15-minute and 30-minute TWA exposures for HFO-
1234yf in MVAC systems in the nonroad vehicles are not likely to exceed 
the ATEL for HFO-1234yf of 100,000 ppm in a one-minute release scenario 
under EPA's worst-case scenario modeling assumptions. The end-use 
exposures estimated by AEM across all scenarios were also well below 
the ATEL for HFO-1234yf. Furthermore, these exposure estimates were 
derived using conservative assumptions that do not necessarily reflect 
a real-world leak scenario or the larger cab size where MVAC systems 
using HFO-1234yf would typically be installed.
    Additionally, the estimated TWA exposure for HFO-1234yf determined 
from AEM's CFD modeling, which models a realistic leak scenario for the 
nonroad vehicles, was significantly below the ATEL for HFO-1234yf of 
100,000 ppm. Construction, forestry, and mining vehicles were modeled 
to represent the five nonroad vehicles. As noted above, these vehicles 
are a more conservative and an approximately equivalent proxy for the 
other four nonroad vehicle types because they have the highest ratio of 
refrigerant charge to cabin volume among the five nonroad vehicles. 
Therefore, the toxicity risks from using HFO-1234yf in the five nonroad 
vehicles is not likely to exceed the ATEL for the five nonroad 
vehicles.
    Concerning workplace exposure during charging, servicing, and 
disposal of the nonroad vehicles addressed in this proposal, we expect 
that professional technicians have proper training and certification 
and have the proper equipment and knowledge to minimize their risks due 
to exposure to refrigerant from an MVAC system. Thus, worker exposure 
to HFO-1234yf is expected to be low. The vehicles are typically charged 
by the OEM. During air conditioning system manufacture (i.e., charging 
at OEM location), points of release would be from connection/
disconnection of temporary lines for charging and recovery equipment, 
although exposure during these activities is expected to be minimal due 
to the use of left-hand threaded fittings on storage cylinders, as 
specified in SAE Standard J2844, intended to help mitigate any releases 
and restrict the possibility of cross-contamination with other 
refrigerants.\66 67 68 69 70\ Furthermore, equipment containing HFO-
1234yf is expected to be equipped with unique fittings for the low-side 
and high-side service ports of the MVAC system, according to SAE 
Standard J639, also intended to help mitigate any releases and restrict 
the possibility of cross-contamination with other refrigerants.\71\
---------------------------------------------------------------------------

    \66\ ICF, 2021a. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Agricultural Tractors Greater than 
40 Horsepower) (New Equipment).
    \67\ ICF, 2021b. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Self-Propelled Agricultural 
Machinery) (New Equipment).
    \68\ ICF, 2021c. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Compact Equipment) (New Equipment).
    \69\ ICF, 2021d. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Construction, Forestry, and Mining 
Equipment) (New Equipment).
    \70\ ICF, 2021e. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Commercial Utility Vehicles) (New 
Equipment).
    \71\ Ibid.
---------------------------------------------------------------------------

    Servicing of the vehicles is expected to take place in high-bays 
and/or outside (e.g., out in the field or other outdoor site) \72\ 
rather than at a typical servicing center for LD vehicles, for example; 
therefore, exposure during servicing is expected to be less than during 
charging the MVAC system during manufacture. Therefore, occupational 
exposure during these activities was conservatively modeled based on 
charging. The modeled maximum 15-minute TWA exposures

[[Page 26285]]

for HFO-1234yf during charging were compared to the short-term exposure 
limit (STEL) of 1,500 ppm. EPA's modeling indicated that the short-term 
(15-minute) worker exposure concentrations of HFO-1234yf are not likely 
to exceed its STEL for the typical or maximum charge size in the 
vehicles during charging or servicing. Additionally, these exposure 
estimates are significantly lower than the RCL and ATEL of 16,000 ppm 
and 100,000 ppm, respectively, for HFO-1234yf, which are limits 
intended to reduce the risks of asphyxiation and acute toxicity hazards 
in normally occupied, enclosed spaces according to ASHRAE Standard 34.
---------------------------------------------------------------------------

    \72\ Chemours, 2019. HFO-1234yf for Use as a Refrigerant. 
Significant New Alternatives Policy Program Submission to the U.S. 
Environmental Protection Agency.
---------------------------------------------------------------------------

    EPA also determined that occupational exposure during disposal of 
all the vehicles, except for construction, forestry, and mining 
equipment, at the typical and maximum charge sizes is not likely to 
exceed the long-term (8-hour) WEEL for HFO-1234yf (i.e., 500 ppm). 
Under the disposal release scenarios for construction, forestry, and 
mining equipment, the modeling showed that occupational exposure during 
disposal of MVAC systems containing HFO-1234yf at the maximum charge 
size (i.e., 3.4 kilograms (120 ounces)) could potentially exceed the 8-
hour long-term exposure limit by 10 ppm. The estimated exposures, 
however, were well below the RCL of 16,000 ppm for HFO-1234yf and were 
derived using conservative assumptions and represent a worst-case 
scenario with a low probability of occurrence. These MVAC systems are 
also disposed of by CAA section 608-certified personnel using proper 
industrial hygiene techniques while wearing PPE to maximize recovery 
efficiency and limit releases. EPA concludes that the manufacture, use, 
servicing, or disposal of HFO-1234yf MVAC systems in the new nonroad 
vehicles addressed in this action does not pose greater toxicity risk 
to workers than the other alternatives when used in accordance with the 
use conditions.
    Additionally, EPA's review of potential toxicity risks of HFO-
1234yf to the general population indicated that HFO-1234yf is not 
expected to pose significantly greater toxicity risk than other 
alternatives for the MVAC systems in the new nonroad vehicles addressed 
in this action. The general population is defined as non-personnel who 
are subject to exposure of the substitute near industrial facilities, 
including manufacturing or equipment production factories, equipment 
operating locations, or recycling centers, rather than personnel at 
end-use. EPA concludes that the use of HFO-1234yf in the new nonroad 
vehicles addressed in this action does not pose significantly greater 
toxicity risk than the other alternatives when used in accordance with 
the use conditions described below in section II.A.4, which are 
intended to mitigate toxicity risks, and recommendations in the SDS and 
EPA's risk screens.
4. What are the use conditions?
    All MVAC refrigerants listed as acceptable are subject to use 
conditions requiring labeling and the use of unique fittings. HFC-152a 
and CO2 are subject to additional use conditions mitigating 
flammability and toxicity as appropriate to the alternative. Neither 
HFC-152a nor CO2 can simply be ``dropped'' into existing 
MVAC systems because they are listed as acceptable only for new 
vehicles.
    EPA is listing HFO-1234yf as acceptable, subject to use conditions, 
in MVAC systems in certain new nonroad vehicles because the use 
conditions are necessary to ensure that use of HFO-1234yf will not have 
a significantly greater overall impact on human health and the 
environment than other alternatives. EPA is updating the existing use 
conditions that are currently required for the use of HFO-1234yf in 
MVAC systems in new LD passenger cars and trucks, MDPVs, HD pickup 
trucks, and complete HD vans and then applying them to all the MVAC 
systems addressed in this action. Manufacturing and service personnel 
or consumers may not be familiar with refrigeration or AC equipment 
containing a flammable refrigerant. These use conditions will be 
sufficiently protective to ensure use of HFO-1234yf in these nonroad 
vehicles does not pose significantly greater risk than use of other 
alternatives.
    The first use condition requires that HFO-1234yf may be used only 
in new MVAC systems which have been designed to address concerns unique 
to flammable refrigerants--i.e., HFO-1234yf may not be used as a 
conversion or ``retrofit'' refrigerant for existing MVACs designed for 
other refrigerants. HFO-1234yf was not submitted under the SNAP program 
for use in retrofitted MVAC systems, and no information was provided on 
how to address hazards if HFO-1234yf were to be used in MVAC systems 
that were not designed for a flammable refrigerant. Therefore, under 
this use condition, HFO-1234yf may be used only in new MVACs that have 
been properly designed for its use.
    The second use condition requires that MVAC systems designed to use 
HFO-1234yf in new agricultural tractors greater than 40 HP; self-
propelled agricultural machinery; compact equipment; construction, 
forestry, and mining equipment; and commercial utility vehicles must 
meet the requirements of SAE J639 (revised November 2020), ``Safety 
Standards for Motor Vehicle Refrigerant Vapor Compression Systems.'' 
This standard sets safety standards that include unique fittings; a 
warning label indicating the refrigerant's identity and that it is a 
flammable refrigerant; and requirements for engineering design 
strategies that include a high-pressure compressor cutoff switch and 
pressure relief devices. This use condition also requires that for 
connections with refrigerant containers for use in professional 
servicing, use fittings must be consistent with SAE J2844 (revised 
January 2013), ``R-1234yf (HFO-1234yf) New Refrigerant Purity and 
Container Requirements for Use in Mobile Air-Conditioning Systems,'' 
which specifies quick-connect fittings that are different from those 
for any other refrigerant. The low-side service port and connections 
will have an outside diameter of 14 mm (0.551 inches), and the high-
side service port will have an outside diameter of 17 mm (0.669 
inches), both accurate to within 2 mm. Under SAE J2844 (revised January 
2013), containers of HFO-1234yf for use in professional servicing of 
MVAC systems must have a left-handed screw valve with a diameter of 0.5 
inches and Acme (trapezoidal) thread with 16 threads per inch.
    HFO-1234yf is mildly flammable (A2L classification) and, like other 
fluorinated refrigerants, can decompose to form the toxic compound 
hydrogen fluoride (HF) when exposed to flame or to sufficient heat. 
Consistent with the conclusion EPA drew at the time of the Agency's 
listing decision for HFO-1234yf in LD vehicles, EPA believes that the 
safety requirements that are included in SAE J639 sufficiently mitigate 
risks of both HF generation and refrigerant ignition (March 29, 2011; 
76 FR 17488) for the nonroad vehicles addressed in this action. For 
example, SAE J639 provides for a pressure relief device designed to 
minimize direct impingement of the refrigerant and oil on hot surfaces 
and for design of the refrigerant circuit and connections to avoid 
refrigerant entering the passenger cabin. The pressure release device 
ensures that pressure in the system will not reach an unsafe level that 
might cause an uncontrolled leak of refrigerant, such as if the MVAC 
system is overcharged. The pressure release device will reduce the 
likelihood that refrigerant leaks would reach hot surfaces that might 
lead to either

[[Page 26286]]

ignition or formation of HF. These elements of the refrigerant circuit 
and connections are designed to prevent refrigerant from entering the 
passenger cabin if there is a leak. Keeping refrigerant out of the 
passenger cabin minimizes the possibility that there would be 
sufficient levels of refrigerant to reach flammable concentrations or 
that HF would be formed and transported where passengers might be 
exposed.
    The third use condition requires the manufacturer of MVAC systems 
and vehicles to conduct Failure Mode and Effects Analysis (FMEA) as 
provided in SAE J1739 (revised January 2021), ``Potential Failure Mode 
and Effects Analysis (FMEA) Including Design FMEA, Supplemental FMEA-
MSR, and Process FMEA,'' and keep records of the FMEA on file for three 
years from the date of creation. SAE J1739 (revised January 2021) 
describes a FMEA as ``a systematic group of activities intended to: (a) 
Recognize and evaluate the potential failure of a product/process and 
the effects and causes of that failure, (b) identify actions that could 
eliminate or reduce the change of the potential failure occurring, and 
(c) document the process.'' Through the FMEA, OEMs determine the 
appropriate protective strategies necessary to ensure the safe use of 
HFO-1234yf across their vehicle fleet. It is standard industry practice 
to perform the FMEA and to keep it on file while the vehicle is in 
production and for several years afterwards. As with the previous use 
condition, this use condition is intended to ensure that agricultural 
tractors greater than 40 HP; self-propelled agricultural machinery; 
compact equipment; construction, forestry, and mining equipment; and 
commercial utility vehicles manufactured with HFO-1234yf MVACs are 
specifically designed to minimize release of the refrigerant into the 
passenger cabin or onto hot surfaces that might result in ignition or 
in generation of HF.

B. Modifications to Use Conditions for MVAC Systems in Other Vehicle 
Types

    For the previous listings of HFO-1234yf in the March 29, 2011 (76 
FR 17488), and December 1, 2016 (81 FR 86778), final rules for MVAC 
systems in certain new vehicles, EPA is modifying the use conditions to 
replace the reference to older versions of SAE J639, SAE J1739, and SAE 
J2844.
    First, EPA is replacing the reference to SAE J639 (revised 2011) in 
the March 2011 and December 2016 final rules with a reference to the 
2020 version of the standard, ``Safety and Design Standards for Motor 
Vehicle Refrigerant Vapor Compression Systems.'' This is the most 
recent version of the SAE J639 standard, which was updated to include 
system design and safety-related requirements for secondary loop HFC-
152a MVAC systems and to make general improvements for clarity.
    Second, EPA is replacing the reference to SAE J1739 (adopted 2009) 
in the March 2011 and December 2016 final rules with a reference to the 
2021 version of the standard, ``Potential Failure Mode and Effects 
Analysis (FMEA) Including Design FMEA, Supplemental FMEA-MSR, and 
Process FMEA.'' The 2021 version is the most recent version of the SAE 
J1739 standard; it was revised to emphasize the process of FMEA 
selection, creation, documentation, reporting, and change management.
    Finally, EPA is replacing the reference to SAE J2844 (revised 2011) 
in the March 2011 final rule with a reference to the 2013 version of 
the standard, ``R-1234yf (HFO-1234yf) New Refrigerant Purity and 
Container Requirements for Use in Mobile Air-Conditioning Systems.'' 
This is the most recent version of the SAE J2844 standard; it was 
updated to add the requirements for certification according to SAE 
J2911, ``Procedure for Certification that Requirements for Mobile Air 
Conditioning System Components, Service Equipment, and Service 
Technician Training Meet SAE J Standards.''

C. Servicing Fittings for Small Cans of HFO-1234yf

    EPA is including a use condition for HFO-1234yf to provide for 
servicing air conditioning systems. The use condition would require 
unique servicing fittings for use with small cans (two pounds or less) 
for servicing of MVAC systems containing HFO-1234yf in the nonroad 
vehicles addressed in this action, as well as servicing of the MVAC 
systems in the vehicles for which HFO-1234yf has already been listed as 
acceptable, subject to use conditions (i.e., new LD passenger cars and 
trucks and new MDPVs, HD pickup trucks, and complete HD vans). The use 
condition is discussed below in section II.C.3, ``What is the use 
condition?''
    EPA previously listed HFO-1234yf as acceptable, subject to use 
conditions, for large containers of HFO-1234yf for professional 
servicing of MVAC systems (76 FR 17488, March 29, 2011; 77 FR 17344, 
March 26, 2012). Redacted submissions and supporting documentation for 
HFO-1234yf in small cans are provided in the docket for this rulemaking 
(EPA-HQ-OAR-2021-0347) at https://www.regulations.gov. As explained in 
the proposed rule (86 FR 68962; December 6, 2021) and below, to help 
evaluate environmental, flammability, and toxicity risks resulting from 
the use of HFO-1234yf in small cans for MVAC servicing, EPA conducted a 
risk screen which is available in the docket for this rulemaking.\73\
---------------------------------------------------------------------------

    \73\ ICF, 2021f. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Small Cans). Substitute: HFO-1234yf.
---------------------------------------------------------------------------

    Servicing of MVAC systems containing HFO-1234yf with small 
refrigerant cans is expected to take place in a variety of locations, 
including professional and residential garages with differing sizes and 
ventilation rates. As discussed below in section II.C.3 regarding the 
use condition, small refrigerant cans must be equipped with a Standard 
Compressed Gas Association (CGA) 166 left-hand thread outlet connection 
valve in accordance with SAE Standard J2844.\74\ The hose connected to 
the vehicle must also use the low side service port per SAE J639.
---------------------------------------------------------------------------

    \74\ SAE J2844 container valve requirements are for HFO-1234yf 
service cylinders with a volume less than or equal to 23 kilograms.
---------------------------------------------------------------------------

    For additional context, we further note that separate from the 
requirements in this action, the sale of such small refrigerant cans 
would be subject to the regulatory requirements under CAA section 608, 
codified at 40 CFR 82.154. These regulations restrict the sale, 
distribution, and offer for sale or distribution of refrigerants, 
including non-exempt substitute refrigerants, like HFO-1234yf, to 
circumstances where certain requirements are met. Specific to the sale 
of small cans of refrigerant, 40 CFR 82.154(c)(1)(ix) provides that 
non-exempt substitute refrigerant for use in an MVAC, e.g., HFO-1234yf, 
may be sold, including to DIYers, if it is in a container designed to 
hold two pounds or less of refrigerant which has a unique fitting, and, 
if manufactured or imported on or after January 1, 2018, has a self-
sealing valve that complies with the self-sealing valve specifications 
codified at 40 CFR 82.154(c)(2). EPA is not modifying the existing CAA 
section 608 provisions under 40 CFR 82.154, including the restriction 
on sale of substitute refrigerants and requirements for self-sealing 
valves. For additional information, EPA directs readers to 40 CFR 
82.152, where EPA defines a self-sealing valve as ``a valve affixed to 
a container of refrigerant that automatically seals when not actively 
dispensing refrigerant and that meets or exceeds established 
performance criteria as identified in Sec.  82.154(c)(2).''

[[Page 26287]]

1. What is the affected end-use?
    As proposed, EPA is listing HFO-1234yf as acceptable, subject to a 
use condition, in small cans (two pounds or less) for servicing of MVAC 
systems in the nonroad vehicles addressed in this action, as well as in 
MVAC systems in the vehicles for which HFO-1234yf has already been 
listed as acceptable, subject to use conditions. For the existing 
listings in the March 29, 2011 (76 FR 17488), and December 1, 2016 (81 
FR 86778), final rules, EPA is revising the use conditions to require 
unique servicing fittings for use with small cans.
2. How does HFO-1234yf compare to other refrigerants for these MVAC 
applications with respect to SNAP criteria?
a. Environmental Impacts
    HFO-1234yf has a GWP of four,75 76 which is similar to 
or lower than the GWP of the other acceptable alternatives for use in 
small cans (i.e., HFC-134a and CO2). HFO-1234yf, HFC-134a, 
and CO2 do not deplete the ozone layer, and are all exempt 
from the regulatory definition of VOC (see 40 CFR 51.100(s)) addressing 
the development of SIPs to attain and maintain the NAAQS. For 
additional information on the environmental impacts of HFO-1234yf, see 
the discussion above in section II.A.3.a.
---------------------------------------------------------------------------

    \75\ Nielsen et al., 2007. Atmospheric chemistry of CF3CF=CH2: 
Kinetics and mechanisms of gas-phase reactions with Cl atoms, OH 
radicals, and O3. Chemical Physics Letters 439, 18-22. Available 
online at: http://www.cogci.dk/network/OJN_174_CF3CF=CH2.pdf.
    \76\ Papadimitriou et al., 2007. CF3CF=CH2 and (Z)-CF3CF=CHF: 
temperature dependent OH rate coefficients and global warming 
potentials. Phys. Chem. Chem. Phys., 2007, Vol. 9, p. 1-13. 
Available online at: http://pubs.rsc.org/en/Content/ArticleLanding/2008/CP/b714382f.
---------------------------------------------------------------------------

b. Flammability
    As discussed above in section II.A.3.b, HFO-1234yf is classified as 
A2L under ASHRAE 34-2013, while HFC-134a and CO2 are 
nonflammable refrigerants. HFO-1234yf is flammable when its 
concentration in air is in the range of 6.2 percent and 12.3 percent by 
volume (62,000 ppm to 123,000 ppm). Due to its flammability, small cans 
of HFO-1234yf for MVAC system servicing could pose a safety concern for 
workers and service personnel or consumers if they are not properly 
handled.
    Servicing of MVAC systems with small refrigerant cans containing 
HFO-1234yf is expected to take place in either a professional garage 
bay or a residential garage. To determine the potential flammability 
risks of a catastrophic release of refrigerant during professional and 
DIY MVAC system servicing using a small refrigerant can, EPA analyzed 
plausible worst-case scenarios to model a catastrophic release of HFO-
1234yf \77\ compared with the LFL of 62,000 ppm for HFO-1234yf.\78\ 
Under these plausible worst-case scenarios, the full charge of the 
refrigerant can is assumed to be emitted into the professional garage 
bay and residential garage with 4.0 and 3.1 air changes per hour 
(ACH),\79\ respectively, over the course of 15 minutes, which 
represents the approximate amount of time required to charge the MVAC 
system.\80\ EPA found that the maximum instantaneous concentrations of 
HFO-1234yf in the lower 0.4 meters of the room did not exceed the LFL 
for HFO-1234yf (i.e., 62,000 ppm) for small refrigerant cans (charge 
size of around 1kg (2 pounds) or less). \81\ EPA also found that the 
maximum instantaneous concentration exceeded 25 percent (15,500 ppm) of 
the LFL for HFO-1234yf for DIY servicing under one of the 
scenarios.\82\ However, the scenario was derived using conservative 
assumptions (e.g., minimum room volume, vertical concentration 
gradient). Furthermore, small refrigerant cans are not likely to be 
used in spaces significantly smaller than those modeled in EPA's 
assessment, which are expected to be large enough to accommodate a 
vehicle and adequate space surrounding the vehicle for the user to 
access the MVAC unit. Finally, HFO-1234yf is difficult to ignite and, 
in the event of ignition, the flames would propagate slowly.\83\ 
Therefore, the risk of fire is minimal if small refrigerant cans 
containing HFO-1234yf meet and are used to service vehicles in rooms 
with volumes in accordance with relevant safety standards as described 
below in section II.C.3.
---------------------------------------------------------------------------

    \77\ In order to simulate the vertical concentration gradient of 
refrigerant following release, it is assumed that 95 percent of the 
leaked refrigerant mixes evenly into the lower 0.4 meters (1.3 feet) 
of the room, and the rest of the refrigerant mixes evenly in the 
remaining volume (Kataoka 2000).
    \78\ ICF, 2021f. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Small Cans). Substitute: HFO-1234yf.
    \79\ The air exchange rates were derived from the requirements 
in ANSI/ASHRAE Standard 62.1-2019, Table 6.1 (ANSI/ASHRAE 2019c). 
Ventilation requirements (presented as cubic feet per minute in the 
standard) were converted to ACH using the assumed room size in the 
residential garage scenario.
    \80\ Perrin Quarles Associates, Inc. (2007) suggests charging 
for up to 15 minutes to fully empty the contents of the refrigerant 
can is a best practice for DIY servicing of an MVAC system. This 
study also indicates that the transfer procedure used for a small 
refrigerant can (e.g., holding upright, rotation method, and other 
flow control methods) influences the transfer time and resulting 
heel remaining in the can.
    \81\ ICF, 2021f. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Small Cans). Substitute: HFO-1234yf.
    \82\ Ibid.
    \83\ HFO-1234yf has a high minimum ignition energy of 5,000-
10,000 mJ and a low burning velocity of 1.5 cm/s (Koban, 2011).
---------------------------------------------------------------------------

    Additionally, EPA considered the submitters' detailed assessments 
of the probability of events that might create a fire and approaches to 
mitigate risks. A CFD modeling was conducted by a submitter to simulate 
a severe refrigerant line leak from a 600-gram MVAC system in a garage 
bay of 84 m\3\ without forced ventilation and found that the flammable 
region of the refrigerant plume under the hood of the vehicle was 
small, ranging from 2 inches to a maximum of 10 inches, which quickly 
dispersed. Similarly, leaks from a small refrigerant can containing 
HFO[hyphen]1234yf during MVAC servicing are not expected to accumulate 
under the vehicle hood in concentrations above the LFL for 
HFO[hyphen]1234yf.
    EPA concludes that the currently available assessments on the use 
of HFO[hyphen]1234yf in small cans for professional and DIY servicing 
of MVAC systems are sufficiently conservative to account for all 
probable flammability risks from the use of HFO[hyphen]1234yf. 
Therefore, the use of HFO[hyphen]1234yf in small cans does not pose 
significantly greater flammability risk than the other alternatives 
when used in accordance with the use condition described below in 
section II.C.3, which is intended to mitigate flammability risks, and 
recommendations in the SDS and EPA's risk screen.
c. Toxicity
    For a discussion of the potential health effects of 
HFO[hyphen]1234yf, see the section II.A.3.c above. In evaluating 
potential asphyxiation and toxicity impacts of HFO[hyphen]1234yf in 
small cans on human health, EPA considered both occupational risk and 
risk to the general population. EPA investigated the risk of 
asphyxiation and of exposure to toxic levels of HFO[hyphen]1234yf for 
plausible worst-case scenarios. According to the results of EPA's 
asphyxiation assessment, the use of HFO[hyphen]1234yf in small 
refrigerant cans does not present a significant risk of 
asphyxiation.\84\ Conditions resulting in oxygen levels under 12 
percent \85\ would only occur with charge sizes that are significantly 
larger than the maximum charge size for

[[Page 26288]]

small refrigerant cans or room sizes that are unlikely for the 
application. In addition, the charge sizes at which an asphyxiation 
concern would exist are also significantly larger (about 18 times) than 
the average charge size of an MVAC system.\86\
---------------------------------------------------------------------------

    \84\ ICF, 2021f. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Small Cans). Substitute: HFO[hyphen]1234yf.
    \85\ Twelve percent oxygen in air (i.e., 120,000 ppm) is the 
NOAEL for hypoxia (ICF 1997).
    \86\ EPA's Vintaging Model (EPA 2020) assumes the refrigerant 
charge size for MVACs to be 0.555-1 kilograms in light-duty vehicles 
and 0.79-1.14 kilograms in light-duty trucks.
---------------------------------------------------------------------------

    To evaluate toxicity risks, EPA estimated 15-minute TWA exposures 
for HFO[hyphen]1234yf in small cans and compared them to the standard 
toxicity limits. The estimated TWA values were conservative as the 
analysis did not consider opened windows or doors, fans operating, 
conditioned airflow (either heated or cooled), or other variables that 
would reduce the levels to which individuals would be exposed. The 
modeling results showed that the estimated 15-minute TWA exposures 
ranging from 3,100 ppm to 11,080 ppm are all lower than the RCL (i.e., 
16,000 ppm) and ATEL (i.e., 100,000 ppm) for HFO[hyphen]1234yf.
    EPA also considered testing and air sampling conducted by a 
submitter to determine potential refrigerant exposure to professional 
servicing technicians or DIY users due to leakage of refrigerant cans 
in a small, closed garage with the condenser fan off and the vehicle 
hood partly open.\87\ The various scenarios investigated included 
releases of 170 grams to 680 grams of refrigerant from both an inverted 
and upright can.\88\ Refrigerant samples were taken under the vehicle 
at 0.15 meters above the floor (representing the potential breathing 
area of a technician present in that space) and in the engine 
compartment. The experimentally derived exposure estimates are also 
significantly lower than the RCL (i.e., 16,000 ppm) and ATEL (i.e., 
100,000 ppm) for HFO[hyphen]1234yf.
---------------------------------------------------------------------------

    \87\ Honeywell International, Inc. 2012. Refrigerant exposure to 
service personnel or DIYers due to leakage of 12 oz charging cans or 
``small cans.'' Experiments Conducted at Honeywell's Research 
Laboratory in Buffalo, NY USA. January 2012.
    \88\ The orientation of the can during servicing determines the 
phase (i.e., liquid or gas) of the refrigerant that is being 
transferred into the MVAC system. When the can is upright, the 
refrigerant transfers as a gas and when the can is inverted, the 
refrigerant transfers as a liquid (Perrin Quarles Associates, Inc., 
2007). Refrigerant can instructions often direct users to hold the 
can upright or rotate its position during servicing.
---------------------------------------------------------------------------

    Additionally, EPA assessed the potential exposures to workers 
during disposal (e.g., collection, transportation) of small refrigerant 
cans containing HFO[hyphen]1234yf.\89\ EPA determined that if proper 
handling and disposal guidelines are followed in accordance with good 
industrial hygiene practices and the SDS for HFO[hyphen]1234yf, there 
is no significant risk to workers during the disposal of 
HFO[hyphen]1234yf from MVAC systems or HFO[hyphen]1234yf small 
refrigerant cans.
---------------------------------------------------------------------------

    \89\ ICF, 2021f. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Small Cans). Substitute: HFO[hyphen]1234yf.
---------------------------------------------------------------------------

    For potential toxicity risks of HFO[hyphen]1234yf to the general 
population, EPA's analysis indicated that HFO[hyphen]1234yf is not 
expected to present an unreasonable risk to human health in the general 
population when used as a refrigerant in small cans for MVAC servicing.
    Based upon EPA's analysis, workplace and general population 
exposure to HFO[hyphen]1234yf in small cans when used according to the 
use condition is not expected to exceed relevant exposure limits. 
Therefore, EPA concludes that the use of HFO[hyphen]1234yf in small 
cans does not pose significantly greater toxicity risks than other 
acceptable refrigerants when used in accordance with the use condition 
described below in section II.C.3, which is intended to mitigate 
toxicity risks, and recommendations in the SDS and EPA's risk screen.
3. What is the use condition?
    EPA's SNAP program has a longstanding approach of requiring unique 
fittings for use with each refrigerant substitute in MVAC systems. This 
is intended to prevent cross contamination of different refrigerants, 
to preserve the purity of recycled refrigerants, and ultimately to 
avoid venting of refrigerant consistent with requirements under CAA 
section 608(c), codified at 40 CFR 82.154(a). In the 1996 SNAP rule 
requiring the use of fittings on all refrigerants submitted for use in 
MVAC systems, EPA urged industry to develop mechanisms to ensure that 
the refrigerant venting prohibition under CAA section 608 and the 
implementing regulations at 40 CFR 82.154 are observed (61 FR 54032; 
October 16, 1996). EPA has issued multiple SNAP rules codified in the 
CFR requiring the use of fittings unique to a refrigerant for use on 
``containers of the refrigerant, on can taps, on recovery, recycling, 
and charging equipment, and on all [motor vehicle] air conditioning 
system service ports.'' (See appendices C and D to subpart G of 40 CFR 
part 82).
    In this rule, EPA is establishing a use condition requiring that 
for connections with small cans (two pounds or less) of 
HFO[hyphen]1234yf use fittings must be consistent with SAE J2844 
(revised January 2013), which specifies quick-connect fittings that are 
different from those for any other refrigerant. The low-side service 
port and connections will have an outside diameter of 14 mm (0.551 
inches), and the high-side service port will have an outside diameter 
of 17 mm (0.669 inches), both accurate to within 2 mm. Under SAE J2844 
(revised January 2013), small cans of HFO[hyphen]1234yf (e.g., for use 
in DIY servicing of MVAC systems) must have a left-handed screw valve 
with a diameter of 0.5 inches and Acme (trapezoidal) thread with 16 
threads per inch.

D. Incorporation by Reference

    As proposed, EPA is adopting the current versions of three 
technical safety standards developed by SAE by incorporating them by 
reference into the use conditions for the nonroad vehicles addressed in 
this action. EPA is also modifying the use conditions for the previous 
listings of HFO[hyphen]1234yf in certain MVAC systems to incorporate by 
reference the most current versions of the three standards. The three 
standards are SAE J639 (revised November 2020), ``Safety and Design 
Standards for Motor Vehicle Refrigerant Vapor Compression Systems;'' 
SAE J1739 (revised January 2021), ``Potential Failure Mode and Effects 
Analysis (FMEA) Including Design FMEA, Supplemental FMEA-MSR, and 
Process FMEA;'' and SAE J2844 (revised January 2013), ``R[hyphen]1234yf 
(HFO[hyphen]1234yf) New Refrigerant Purity and Container Requirements 
for Use in Mobile Air-Conditioning Systems.'' Section II.A.4 of this 
preamble discusses these standards in greater detail.
    EPA finds, as in past rules, that it is appropriate to reference 
consensus standards that set conditions to reduce risk. As in past 
listings of flammable refrigerants, we find that such standards have 
already gone through a development phase that incorporates the latest 
findings and research. Likewise, such standards have gone through a 
vetting and refinement process that provides the affected parties an 
opportunity to comment. For the U.S. MVAC industry, EPA sees SAE 
standards in general as a pervasively used body of work to address 
risks, and these standards are the most applicable and recognized by 
the U.S. market.
    Incorporation by reference allows federal agencies to comply with 
the requirement to publish rules in the Federal Register and the Code 
of Federal Regulations by referring to material already published 
elsewhere. The legal effect of incorporation by reference is that the 
material is treated as if it were published in the Federal Register and 
Code of Federal Regulations.
    SAE J639, J1739, and J2844 are available for purchase by mail at: 
SAE

[[Page 26289]]

Customer Service, 400 Commonwealth Drive, Warrendale, PA 15096-0001; 
Telephone: 1-877-606-7323 in the U.S. or Canada (other countries dial 
1-724-776-4970); internet address for SAE J639: https://www.sae.org/standards/content/j639_201112/; internet address for SAE J1739: https://www.sae.org/standards/content/j1739_202101/; internet address for SAE 
J2844: https://www.sae.org/standards/content/j2844_201301/. The cost of 
SAE J639, J1739, and J2844 is $85 each for an electronic or hard copy. 
The cost of obtaining these standards is not a significant financial 
burden for manufacturers of MVAC systems, and purchase is not required 
for those selling, installing, or servicing the MVAC systems covered by 
these standards. Therefore, the EPA concludes that SAE J639, J1739, and 
J2844 are reasonably available.

E. What is the relationship between this SNAP rule and other federal 
rules?

1. Significant New Use Rule for HFO[hyphen]1234yf Under the Toxic 
Substances Control Act
    In a final rule published on March 29, 2011 (76 FR 17488), EPA 
noted that the listing of HFO[hyphen]1234yf as acceptable, subject to 
use conditions, in new passenger cars and trucks did not apply to small 
cans. EPA stated that the Agency ``would require additional information 
on consumer risk and a set of unique fittings from the refrigerant 
manufacturer for use with small cans or containers of HFO[hyphen]1234yf 
before we would be able to issue a revised rule that allows for 
consumer filling, servicing, or maintenance of MVAC systems with 
HFO[hyphen]1234yf'' \90\ and that use of small cans would need to be 
consistent with EPA's final SNUR for HFO[hyphen]1234yf under TSCA 
(October 27, 2010; 75 FR 65987). EPA has since revised the SNUR (80 FR 
37166, June 30, 2015) to require the submission of a significant new 
use notice (SNUN) for commercial use of HFO[hyphen]1234yf other than in 
passenger cars and vehicles in which the original charging of MVAC 
systems with HFO[hyphen]1234yf was done by the OEM and use of 
HFO[hyphen]1234yf in consumer products other than products used to 
recharge the MVAC systems in passenger cars and vehicles in which the 
original charging of MVAC systems with HFO[hyphen]1234yf was done by 
the OEM, among other things. Manufacturers of small cans of 
HFO[hyphen]1234yf have also submitted a unique fitting specifically for 
use with small can taps and small refrigerant cans for EPA's review. 
Today's listing of HFO[hyphen]1234yf would apply to small cans, 
weighing two pounds or less, for DIY or professional use. Consistent 
with the revised June 2015 SNUR for HFO[hyphen]1234yf, commercial use 
or use in consumer products to recharge MVAC systems with 
HFO[hyphen]1234yf in passenger cars and vehicles may only occur without 
submission of a SNUN and review by EPA if the OEM originally charged 
the system with HFO[hyphen]1234yf.
---------------------------------------------------------------------------

    \90\ EPA, 2011. Protection of Stratospheric Ozone: New 
Substitute in the Motor Vehicle Air Conditioning Sector Under the 
Significant New Alternatives Policy (SNAP) Program; Final Rule. 
March 29, 2011 (76 FR 17488). Available online at: https://www.govinfo.gov/content/pkg/FR-2011-03-29/pdf/2011-6268.pdf.
---------------------------------------------------------------------------

    EPA is including a reference to the June 2015 SNUR (80 FR 37166) in 
Appendix B subpart G of part 82, under the `Comments' column, for the 
listings of HFO[hyphen]1234yf for the nonroad vehicles addressed in 
this action. EPA is also modifying the existing listings of 
HFO[hyphen]1234yf as acceptable, subject to use conditions, for various 
vehicle types, by including the reference to the June 2015 SNUR in the 
Comments column in Appendix B subpart G of part 82.
2. CAA Sections 608 and 609
    Today's action will not have any impact on EPA's regulations under 
sections 608 or 609 of the Clean Air Act. Among other things, CAA 
section 608 prohibits individuals from knowingly venting or otherwise 
releasing into the environment any refrigerants except those 
specifically exempted in certain end uses, while maintaining, 
servicing, repairing, or disposing of air conditioning or refrigeration 
equipment. HFO[hyphen]1234yf is not exempt from the venting prohibition 
in any application; therefore, knowing release of HFO[hyphen]1234yf 
from MVAC systems in the nonroad vehicles addressed in this action, or 
any other MVAC system, by any person maintaining, servicing, repairing, 
or disposing of such systems is prohibited. MVAC end-of-life disposal 
and recycling specifications are also covered under CAA section 608 and 
EPA's regulations issued under that section of the Act, which are 
codified at subpart F of 40 CFR part 82. In addition, as mentioned 
above in sections I.A and II.C, there are additional requirements that 
concern the sale or offer for sale of refrigerants, including a sales 
restriction under 40 CFR subpart F and specifically at 82.154(c)(1) and 
related specifications for self-sealing valves at 82.154(c)(2). This 
action does not modify the provisions under 40 CFR 82.154, including 
the restriction on sale of substitute refrigerants and requirements for 
self-sealing valves. The Agency is not revising regulations promulgated 
under CAA section 608 in this action.
    CAA section 609 establishes standards and requirements regarding 
the servicing or repair of MVAC systems. EPA has issued regulations 
implementing this statutory requirement and those regulations are 
codified at subpart B of 40 CFR part 82. Under section 609 and its 
implementing regulations, no person repairing or servicing motor 
vehicles for consideration \91\ may perform any service on an MVAC that 
involves the refrigerant without properly using approved refrigerant 
recovery or recovery and recycling equipment, and no such person may 
perform such service unless such person has been properly trained and 
certified. Refrigerant handling equipment must be certified by EPA or 
an independent organization approved by EPA. The statutory and 
regulatory provisions regarding MVAC servicing apply to all 
refrigerants, including HFO[hyphen]1234yf.
---------------------------------------------------------------------------

    \91\ Service for consideration means receiving something of 
worth or value to perform service, whether in money, credit, goods, 
or services.
---------------------------------------------------------------------------

3. Will this action affect EPA's HD greenhouse gas standards?
    The Phase 1 HD Greenhouse Gas (GHG) rule (76 FR 57106; September 
15, 2011) set GHG standards for the HD industry in three discrete 
categories--combination tractors, HD pickups and vans, and vocational 
vehicles. The Phase 1 rule also set separate standards for engines that 
power vocational vehicles and combination tractors--based on the 
relative degree of homogeneity among vehicles within each category. As 
part of the Phase 1 HD GHG standards, EPA finalized a low leakage 
standard of 1.50 percent leakage per year for AC systems installed in 
HD pickup trucks and vans and combination tractors for model years 2014 
and later. On October 25, 2016, EPA finalized Phase 2 HD GHG standards 
that built on the existing Phase 1 HD GHG standards (81 FR 73478). The 
nonroad vehicles for which EPA is listing HFO[hyphen]1234yf are not 
regulated under the Phase 1 or Phase 2 HD GHG standards. Additionally, 
today's action does not have a direct impact on the HD GHG standards, 
either for Phase 1 or Phase 2.

F. Response to Comments

    EPA received four comments on the proposed rule from refrigerant 
suppliers and equipment manufacturers. All commenters strongly 
supported finalizing the rule as proposed, particularly the proposal to 
list

[[Page 26290]]

HFO[hyphen]1234yf as acceptable, subject to use conditions, in certain 
nonroad vehicle air conditioning systems. One commenter noted that the 
similarities between the proposed use conditions for the nonroad 
vehicles and those required for certain onroad vehicles ``will prevent 
confusion and help harmonize the industry as [HFO-]1234yf usage expands 
to nonroad vehicles.'' Another commenter stated that the proposed 
listings of HFO[hyphen]1234yf in the nonroad vehicles would ``provide 
manufacturers with regulatory certainty so they can design and 
manufacture new equipment using HFO[hyphen]1234yf and transition to 
lower GWP solutions.'' EPA acknowledges the support for the proposed 
rule and is finalizing the listings and changes as proposed.
    In the proposed rule, EPA requested information on the development 
of HFO[hyphen]1234yf MVAC systems for types of nonroad or onroad HD 
vehicles not covered by this rulemaking, particularly onroad trucks 
(i.e., Class 4-8 trucks between 14,001 and 33,000 or greater pounds). 
Two commenters supported the expanded use of HFO[hyphen]1234yf in HD 
onroad trucks greater than 14,000 pounds. One commenter estimated that 
manufacturers would need at least five to ten years to fully transition 
from HFC-134a to HFO[hyphen]1234yf and noted a few potential technical 
challenges. However, the commenter stated that ``medium- and heavy-duty 
truck manufacturers are addressing the challenge with urgency,'' and 
encouraged EPA to initiate rulemaking to list HFO[hyphen]1234yf for HD 
onroad trucks greater than 14,000 pounds. EPA acknowledges the 
commenters' support for the listing of HFO[hyphen]1234yf in additional 
onroad vehicles and will consider these comments as it evaluates 
possible future actions.

III. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is not a significant regulatory action and was 
therefore not submitted to the Office of Management and Budget (OMB) 
for review.

B. Paperwork Reduction Act (PRA)

    This action does not impose any new information collection burden 
under the PRA. OMB has previously approved the information collection 
activities contained in the existing regulations and has assigned OMB 
control number 2060-0226. The approved Information Collection Request 
includes five types of respondent reporting and recordkeeping 
activities pursuant to SNAP regulations: Submission of a SNAP petition, 
filing a TSCA/SNAP Addendum, notification for test marketing activity, 
recordkeeping for substitutes acceptable subject to use restrictions, 
and recordkeeping for small volume uses. This rule contains no new 
requirements for reporting or recordkeeping.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. In 
making this determination, EPA concludes that the impact of concern for 
this rule is any significant adverse economic impact on small entities 
and that the agency is certifying that this rule will not have a 
significant economic impact on a substantial number of small entities 
if the rule has no net burden on the small entities subject to the 
rule. Because the use conditions are consistent with industry consensus 
standards, no change in business practice is required to meet the use 
conditions, resulting in no adverse impact compared to the absence of 
this final rule. Thus, the rule would not impose new costs on small 
entities.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in 
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect 
small governments. The action imposes no enforceable duty on any state, 
local or tribal governments or the private sector.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action does not have tribal implications as specified in 
Executive Order 13175. It will not have substantial direct effects on 
tribal governments, on the relationship between the Federal government 
and Indian tribes, or on the distribution of power and responsibilities 
between the Federal government and Indian tribes, as specified in 
Executive Order 13175. Thus, Executive Order 13175 does not apply to 
this action.

G. Executive Order 13045: Protection of Children From Environmental 
Health and Safety Risks

    This action is not subject to Executive Order 13045 because it is 
not economically significant as defined in Executive Order 12866, and 
because EPA does not believe the environmental health or safety risks 
addressed by this action present a disproportionate risk to children. 
This action's health and risk assessments are contained in the 
comparisons of toxicity for HFO[hyphen]1234yf, as well as in the risk 
screens for HFO[hyphen]1234yf. The risk screens are in the docket for 
this rulemaking.

H. Executive Order 13211: Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This action is not subject to Executive Order 13211, because it is 
not a significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act

    This action involves technical standards. EPA is adopting the 
current versions of three technical safety standards developed by SAE 
by incorporating them by reference into the use conditions for the 
nonroad vehicles addressed in this action. EPA is also modifying the 
use conditions for the previous listings of HFO[hyphen]1234yf in MVAC 
systems to incorporate by reference the most current versions of the 
three standards. The use conditions ensure that HFO[hyphen]1234yf does 
not present significantly greater risk to human health or the 
environment than other alternatives available for use in MVAC. 
Specifically, the three standards are:
    1. SAE J639: Safety and Design Standards for Motor Vehicle 
Refrigerant Vapor Compression Systems (revised November 2020). This 
document establishes safety standards for HFO[hyphen]1234yf MVAC 
systems that include unique fittings; a warning label indicating the 
refrigerant's identity and that it is a flammable refrigerant; and 
requirements for engineering design strategies that include a high-
pressure compressor cutoff switch and pressure relief devices. This 
standard is available at https://www.sae.org/standards/content/j639_201112/.
    2. SAE J1739: Potential Failure Mode and Effects Analysis (FMEA) 
Including Design FMEA, Supplemental FMEA-MSR, and Process FMEA (revised 
January 2021). This standard describes potential FMEA in design and 
potential

[[Page 26291]]

FMEA in manufacturing and assembly processes. It requires manufacturers 
of MVAC systems and vehicles to conduct a FMEA and assists users in the 
identification and mitigation of risk by providing appropriate terms, 
requirements, ranking charts, and worksheets. This standard is 
available at https://www.sae.org/standards/content/j1739_202101/.
    3. SAE J2844: R[hyphen]1234yf (HFO[hyphen]1234yf) New Refrigerant 
Purity and Container Requirements for Use in Mobile Air-Conditioning 
Systems (revised January 2013). This standard sets purity standards and 
describes container requirements, including fittings for refrigerant 
cylinders. For connections with refrigerant containers for use in 
professional servicing, use fittings must be consistent with SAE J2844 
(revised January 2013). For connections with small refrigerant cans for 
consumer or professional use, use fittings must have a diameter of 0.5 
inches, a thread pitch of 16 thread per inch, and a left thread 
direction, consistent with SAE J2844. This standard is available at 
https://www.sae.org/standards/content/j2844_201301/.
    These standards may be purchased by mail at: SAE Customer Service, 
400 Commonwealth Drive, Warrendale, PA 15096-0001; by telephone: 1-877-
606-7323 in the United States or 724-776-4970 outside the United States 
or in Canada. The cost of SAE J639, SAE J1739, and SAE J2844 is $85 
each for an electronic or hardcopy. The cost of obtaining these 
standards is not a significant financial burden for manufacturers of 
MVAC systems and purchase is not required for those selling, 
installing, and servicing the systems. Therefore, EPA concludes that 
the use of SAE J639, SAE J1739, and SAE J2844 are reasonably available.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    A regulatory action may involve potential environmental justice 
concerns if it could: (1) Create new disproportionate impacts on people 
of color, communities of low-income, and/or indigenous peoples; (2) 
exacerbate existing disproportionate impacts on people of color, 
communities of low-income, and/or indigenous peoples; or (3) present 
opportunities to address existing disproportionate impacts on people of 
color, communities of low-income, and/or indigenous peoples through the 
action under development.
    EPA believes that this action does not have disproportionately high 
and adverse human health or environmental effects on people of color, 
communities of low-income and/or indigenous peoples, as specified in 
Executive Order 12898 (59 FR 7629, February 16, 1994). The listings for 
HFO[hyphen]1234yf in the vehicle types addressed in this action would 
provide additional lower-GWP alternatives for the MVAC end-use. By 
providing a lower-GWP alternative for this end-use, this final rule is 
also anticipated to reduce the use and eventual emissions of potent 
GHGs in this end-use, which could help to reduce the effects of climate 
change, including the public health and welfare effects on people of 
color, communities of low-income and/or indigenous peoples. This 
action's health and environmental risk assessments are contained in the 
comparison of health and environmental risks for HFO[hyphen]1234yf, as 
well as in the risk screens that are available in the docket for this 
rulemaking. EPA's analysis indicates that other environmental impacts 
and human health impacts of HFO[hyphen]1234yf are comparable to or less 
than those of other substitutes that are listed as acceptable for the 
same end-use. Based on these considerations, EPA expects that the 
effects on people of color, communities of low-income and/or indigenous 
peoples would not be disproportionately high and adverse.

K. Congressional Review Act (CRA)

    This action is subject to the CRA, and EPA will submit a rule 
report to each House of the Congress and to the Comptroller General of 
the United States. This action is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

IV. References

    Unless specified otherwise, all documents are available 
electronically through the Federal Docket Management System, Docket 
number EPA-HQ-OAR-2021-0347.
AEM, 2019. Risk Assessment for HFO[hyphen]1234yf in Agricultural 
Tractors >= 40 HP including 2WD, MFD, 4WD and Track Type Equipment.
AEM, 2020a. Risk Assessment for HFO[hyphen]1234yf in Self-Propelled 
Agricultural Machinery including Combines, Forage Harvesters, 
Sprayers, and Windrowers.
AEM, 2020b. Risk Assessment for HFO[hyphen]1234yf in Compact 
Equipment (Examples include Tractors <40HP, Turf Equipment, Skid 
Steer, Mini-Excavators and Track Loaders)
AEM, 2020c. Risk Assessment for HFO[hyphen]1234yf in Construction, 
Forestry, and Mining Equipment.
AEM, 2020d. Risk Assessment for HFO[hyphen]1234yf in Commercial 
Utility Vehicles.
AEM, 2020e. CFD Leak Modeling-Supplemental Information to Compliment 
AEM Machine Form RAs.
AEM, 2021. Appendix A: Machine Forms as Classified by AEM 
Membership.
ASHRAE, 2019. ANSI/ASHRAE Standard 34-2019: Designation and Safety 
Classification of Refrigerants.
Chemours, 2019. HFO[hyphen]1234yf for Use as a Refrigerant. 
Significant New Alternatives Policy Program Submission to the U.S. 
Environmental Protection Agency.
CRP, 2008. Risk Assessment for Alternative Refrigerants 
HFO[hyphen]1234yf Phase II. Prepared for SAE International 
Cooperative Research Program 1234 by Gradient Corporation.
CRP, 2009. Risk Assessment for Alternative Refrigerants 
HFO[hyphen]1234yf and R[hyphen]744 (CO2) Phase III. Prepared for SAE 
International Cooperative Research Program 1234 by Gradient 
Corporation.
CRP, 2013. SAE International Cooperative Research Project 
CRP1234[hyphen]4 on R[hyphen]1234yf Safety, Finishes Work and 
Presents Conclusions. Available online at: http://www.sae.org/servlets/pressRoom?OBJECT_TYPE=PressReleases&PAGE=showRelease&RELEASE_ID=2146.

DuPont and Honeywell, 2008. Guidelines for Use and Handling of 
HFO[hyphen]1234yf (v8.0).
EPA, 2005. Risk Analysis for Alternative Refrigerant in Motor 
Vehicle Air Conditioning.
EPA, 2011. Protection of Stratospheric Ozone: New Substitute in the 
Motor Vehicle Air Conditioning Sector Under the Significant New 
Alternatives Policy (SNAP) Program; Final Rule. March 29, 2011 (76 
FR 17488). Available online at: https://www.govinfo.gov/content/pkg/FR-2011-03-29/pdf/2011-6268.pdf.
EPA, 2016. Protection of Stratospheric Ozone: Update to the 
Refrigerant Management Requirements Under the Clean Air Act. 
November 18, 2016. 81 FR 82272. Available online at: https://www.regulations.gov/document?D=EPA-HQ-OAR-2015-0453-0125.
EPA, 2021. Basic Information about the Emission Standards Reference 
Guide for On-road and Nonroad Vehicles and Engines. Available online 
at https://www.epa.gov/emission-standards-reference-guide/basic-information-about-emission-standards-reference-guide-road.
Exponent, 2008. HFO[hyphen]1234yf Refrigerant Concentration and 
Ignition Tests in Full-Scale Vehicle Passenger Cabin and Engine 
Compartment.
ICF, 1997. Physiological Effects of Alternative Fire Protection 
Agents--Hypoxic Atmospheres Conference. Stephanie Skaggs prepared 
the proceedings of the conference held May 22, 1997 in New London, 
CT.
ICF, 2008a. Air Conditioning Refrigerant Charge Size to Passenger 
Compartment Volume Ratio Analysis.
ICF, 2008b. Revised Characterization of U.S. Hybrid and Small Car 
Sales (Historical and Predicted) and Hybrid Vehicle Accidents.
ICF, 2009a. Revised Final Draft Assessment of the Potential Impacts 
of HFO[hyphen]1234yf and the Associated Production of TFA on Aquatic 
Communities and Local Air Quality.
ICF, 2009b. Risk Screen on Substitutes for CFC-12 in Motor Vehicle 
Air Conditioning: Substitute: HFO[hyphen]1234yf.
ICF, 2010a. Summary of HFO[hyphen]1234yf Emissions Assumptions.

[[Page 26292]]

ICF, 2010b. Summary of Updates to the Vintaging Model that Impacted 
HFO[hyphen]1234yf Emissions Estimates.
ICF, 2010c. Revised Assessment of the Potential Impacts of 
HFO[hyphen]1234yf and the Associated Production of TFA on Aquatic 
Communities, Soil and Plants, and Local Air Quality.
ICF, 2010d. Sensitivity Analysis CMAQ results on projected maximum 
TFA rainwater concentrations and maximum 8-hr ozone concentrations.
ICF, 2016. Technical Support Document for Acceptability Listing of 
HFO[hyphen]1234yf for Motor Vehicle Air Conditioning in Limited 
Heavy-Duty Applications.
ICF, 2021a. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles Agricultural Tractors Greater than 40 
Horsepower) (New Equipment).
ICF, 2021b. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles Self-Propelled Agricultural 
Machinery) (New Equipment).
ICF, 2021c. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles Compact Equipment) (New Equipment).
ICF, 2021d. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles--Construction, Forestry, and Mining 
Equipment) (New Equipment).
ICF, 2021e. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Nonroad Vehicles Commercial Utility Vehicles) (New 
Equipment).
ICF, 2021f. Risk Screen on Substitutes in Motor Vehicle Air 
Conditioning (Small Cans). Substitute: HFO[hyphen]1234yf.
Kataoka, O., Yoshizawa, M., & Hirakawa, T., 2000. Allowable Charge 
Limit of Flammable Refrigerants and Ventilation Requirements. Daikin 
Industries. International Refrigeration and Air Conditioning 
Conference. Paper 506. Available online at: http://docs.lib.purdue.edu/iracc/506.
Nielsen, et al., 2007. Atmospheric chemistry of CF3CF=CH2: Kinetics 
and mechanisms of gas-phase reactions with Cl atoms, OH radicals, 
and O3. Chemical Physics Letters 439, 18-22. Available online at: 
http://www.cogci.dk/network/OJN_174_CF3CF=CH2.pdf.
Papadimitriou, et al., 2007. CF3CF=CH2 and (Z)-CF3CF=CHF: 
temperature dependent OH rate coefficients and global warming 
potentials. Phys. Chem. Chem. Phys., 2007, Vol. 9, p. 1-13. 
Available online at: http://pubs.rsc.org/en/Content/ArticleLanding/2008/CP/b714382f.
Perrin Quarles Associates, Inc., 2007. Disposable Container Heel 
Testing Study Report. Prepared for United States Environmental 
Protection Agency by Perrin Quarles Associates, Inc. March 21, 2007.
SAE, 2013. Standard J2844: R[hyphen]1234yf (HFO[hyphen]1234yf) New 
Refrigerant Purity and Container Requirements for Use in Mobile Air-
Conditioning Systems. (Revised January 2013).
SAE, 2019. Standard J2772: Measurement of Passenger Compartment 
Refrigerant Concentrations Under System Refrigerant Leakage 
Conditions. SAE International. (Revised September 2019).
SAE, 2020. Standard J639: Safety and Design Standards for Motor 
Vehicle Refrigerant Vapor Compression Systems. (Revised November 
2020).
SAE, 2021. Standard J1739: Potential Failure Mode and Effects 
Analysis (FMEA) Including Design FMEA, Supplemental FMEA-MSR, and 
Process FMEA. (Revised January 2021).
Wagner, J., 2021. Email from John Wagner, Association of Equipment 
Manufacturers to Chenise Farquharson, EPA.

List of Subjects in 40 CFR Part 82

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Incorporation by reference, Recycling, Reporting 
and recordkeeping requirements, Stratospheric ozone layer, Motor 
vehicle air conditioning.

Michael S. Regan,
Administrator.

    For the reasons set forth in the preamble, EPA amends 40 CFR part 
82 as follows:

PART 82--PROTECTION OF STRATOSPHERIC OZONE

0
1. The authority citation for part 82 continues to read as follows:

    Authority:  42 U.S.C. 7414, 7601, 7671-7671q.

Subpart G--Significant New Alternatives Policy Program

0
2. Appendix B to subpart G of part 82 is amended by
0
a. In the table titled ``Refrigerants--Acceptable Subject to Use 
Conditions'',
0
i. Revising the entries for ``CFC-12 Automobile Motor Vehicle Air 
Conditioning (New equipment in passenger cars and light-duty trucks 
only)'', ``Motor vehicle air conditioning (newly manufactured medium-
duty passenger vehicles)'', ``Motor vehicle air conditioning (newly 
manufactured heavy-duty pickup trucks)'', and ``Motor vehicle air 
conditioning (newly manufactured complete heavy-duty vans only)''; and
0
ii. Adding entries, in the following order at the end of the table, for 
``Motor vehicle air conditioning (newly manufactured nonroad 
agricultural tractors with greater than 40 horsepower)'', ``Motor 
vehicle air conditioning (newly manufactured nonroad self-propelled 
agricultural machinery)'', ``Motor vehicle air conditioning (newly 
manufactured nonroad compact equipment)'', ``Motor vehicle air 
conditioning (newly manufactured nonroad construction, forestry, and 
mining equipment)'', and ``Motor vehicle air conditioning (newly 
manufactured nonroad commercial utility vehicles)''; and
0
b. Removing ``Note 1''.
    The revisions and additions read as follows:

[[Page 26293]]



    Appendix B to Subpart G of Part 82--Substitutes Subject to Use Restrictions and Unacceptable Substitutes
                               Refrigerants--Acceptable Subject to Use Conditions
----------------------------------------------------------------------------------------------------------------
          Application              Substitute         Decision            Conditions              Comments
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
CFC-12 Automobile Motor         HFO[hyphen]1234y  Acceptable        As of June 3, 2022:..  Additional training
 Vehicle Air Conditioning (New   f as a            subject to use   (1) HFO[hyphen]1234yf   for service
 equipment in passenger cars     substitute for    conditions.       MVAC systems must      technicians
 and light-duty trucks only).    CFC-12.                             adhere to all of the   recommended.
                                                                     safety requirements   HFO[hyphen]1234yf is
                                                                     of SAE J639,4 7        also known as
                                                                     including              2,3,3,3-tetrafluoro-
                                                                     requirements for a     prop-1-ene (CAS.
                                                                     flammable              Reg. No. 754-12-1).
                                                                     refrigerant warning   Consistent with EPA's
                                                                     label, high-pressure   Significant New Use
                                                                     compressor cutoff      Rule for
                                                                     switch and pressure    HFO[hyphen]1234yf
                                                                     relief devices, and    under the Toxic
                                                                     unique fittings. For   Substances Control
                                                                     connections with       Act, commercial
                                                                     refrigerant            users or consumers
                                                                     containers for use     can only recharge
                                                                     in professional        MVAC systems with
                                                                     servicing, use         HFO[hyphen]1234yf
                                                                     fittings must be       where the original
                                                                     consistent with SAE    charging of the
                                                                     J2844.6 7 For          system with
                                                                     connections with       HFO[hyphen]1234yf
                                                                     small refrigerant      was done by the
                                                                     cans for consumer or   original equipment
                                                                     professional use,      manufacturer.
                                                                     use fittings must     Refrigerant
                                                                     have a diameter of     containers of
                                                                     0.5 inches, a thread   HFO[hyphen]1234yf
                                                                     pitch of 16 thread     for use in
                                                                     per inch, and a left   professional
                                                                     thread direction,      servicing are from 5
                                                                     consistent with SAE    lbs. (2.3 L) to 50
                                                                     J2844..                lbs. (23 L) in size.
                                                                    (2) Manufacturers      Requirements for
                                                                     must conduct Failure   handling, storage,
                                                                     Mode and Effect        and transportation
                                                                     Analysis (FMEA) as     of compressed gases
                                                                     provided in SAE        apply to this
                                                                     J1739.5 7              refrigerant, such as
                                                                     Manufacturers must     regulations of the
                                                                     keep the FMEA on       Occupational Safety
                                                                     file for at least      and Health
                                                                     three years from the   Administration at 29
                                                                     date of creation.      CFR 1910.101 and the
                                                                                            Department of
                                                                                            Transportation's
                                                                                            requirements at 49
                                                                                            CFR 171-179.
                                                                                           Requirements for
                                                                                            handling, storage,
                                                                                            and transportation
                                                                                            of compressed gases
                                                                                            apply to this
                                                                                            refrigerant, such as
                                                                                            regulations of the
                                                                                            Occupational Safety
                                                                                            and Health
                                                                                            Administration at 29
                                                                                            CFR 1910.101 and the
                                                                                            Department of
                                                                                            Transportation's
                                                                                            requirements at 49
                                                                                            CFR 171-179.
 
                                                  * * * * * * *
Motor vehicle air conditioning  HFO[hyphen]1234y  Acceptable        As of June 3, 2022:    Additional training
 (newly manufactured medium-     f.                subject to use   (1) HFO[hyphen]1234yf   for service
 duty passenger vehicles).                         conditions.       MVAC systems must      technicians
                                                                     adhere to all of the   recommended.
                                                                     safety requirements   HFO[hyphen]1234yf is
                                                                     of SAE J639,4 7        also known as
                                                                     including              2,3,3,3-tetrafluoro-
                                                                     requirements for a     prop-1-ene (CAS.
                                                                     flammable              Reg. No. 754-12-1).
                                                                     refrigerant warning   Consistent with EPA's
                                                                     label, high-pressure   Significant New Use
                                                                     compressor cutoff      Rule for
                                                                     switch and pressure    HFO[hyphen]1234yf
                                                                     relief devices, and    under the Toxic
                                                                     unique fittings. For   Substances Control
                                                                     connections with       Act, commercial
                                                                     refrigerant            users or consumers
                                                                     containers for use     can only recharge
                                                                     in professional        MVAC systems with
                                                                     servicing, use         HFO[hyphen]1234yf
                                                                     fittings must be       where the original
                                                                     consistent with SAE    charging of the
                                                                     J2844.6 7 For          system with
                                                                     connections with       HFO[hyphen]1234yf
                                                                     small refrigerant      was done by the
                                                                     cans for consumer or   original equipment
                                                                     professional use,      manufacturer.
                                                                     use fittings must
                                                                     have a diameter of
                                                                     0.5 inches, a thread
                                                                     pitch of 16 thread
                                                                     per inch, and a left
                                                                     thread direction,
                                                                     consistent with SAE
                                                                     J2844.
                                                                    (2) Manufacturers
                                                                     must conduct Failure
                                                                     Mode and Effect
                                                                     Analysis (FMEA) as
                                                                     provided in SAE
                                                                     J1739.5 7
                                                                     Manufacturers must
                                                                     keep the FMEA on
                                                                     file for at least
                                                                     three years from the
                                                                     date of creation.
Motor vehicle air conditioning  HFO[hyphen]1234y  Acceptable        As of June 3, 2022:    Additional training
 (newly manufactured heavy-      f.                subject to use   (1) HFO[hyphen]1234yf   for service
 duty pickup trucks).                              conditions.       MVAC systems must      technicians
                                                                     adhere to all of the   recommended.
                                                                     safety requirements   HFO[hyphen]1234yf is
                                                                     of SAE J639,4 7        also known as
                                                                     including              2,3,3,3-tetrafluoro-
                                                                     requirements for a     prop-1-ene (CAS No.
                                                                     flammable              754-12-1).
                                                                     refrigerant warning   Consistent with EPA's
                                                                     label, high-pressure   Significant New Use
                                                                     compressor cutoff      Rule for
                                                                     switch and pressure    HFO[hyphen]1234yf
                                                                     relief devices, and    under the Toxic
                                                                     unique fittings. For   Substances Control
                                                                     connections with       Act, commercial
                                                                     refrigerant            users or consumers
                                                                     containers for use     can only recharge
                                                                     in professional        MVAC systems with
                                                                     servicing, use         HFO[hyphen]1234yf
                                                                     fittings must be       where the original
                                                                     consistent with SAE    charging of the
                                                                     J2844.6 7 For          system with
                                                                     connections with       HFO[hyphen]1234yf
                                                                     small refrigerant      was done by the
                                                                     cans for consumer or   original equipment
                                                                     professional use,      manufacturer.
                                                                     use fittings must
                                                                     have a diameter of
                                                                     0.5 inches, a thread
                                                                     pitch of 16 thread
                                                                     per inch, and a left
                                                                     thread direction,
                                                                     consistent with SAE
                                                                     J2844.
                                                                    (2) Manufacturers
                                                                     must conduct Failure
                                                                     Mode and Effect
                                                                     Analysis (FMEA) as
                                                                     provided in SAE
                                                                     J1739.5 7
                                                                     Manufacturers must
                                                                     keep the FMEA on
                                                                     file for at least
                                                                     three years from the
                                                                     date of creation.

[[Page 26294]]

 
Motor vehicle air conditioning  HFO[hyphen]1234y  Acceptable        As of June 3, 2022:    Additional training
 (newly manufactured complete    f.                subject to use   (1) HFO[hyphen]1234yf   for service
 heavy-duty vans only).                            conditions.       MVAC systems must      technicians
                                                                     adhere to all of the   recommended.
                                                                     safety requirements   HFO[hyphen]1234yf is
                                                                     of SAE J639,4 7        also known as
                                                                     including              2,3,3,3-tetrafluoro-
                                                                     requirements for a     prop-1-ene (CAS No.
                                                                     flammable              754-12-1).
                                                                     refrigerant warning   HFO[hyphen]1234yf is
                                                                     label, high-pressure   acceptable for
                                                                     compressor cutoff      complete heavy-duty
                                                                     switch and pressure    vans. Complete heavy-
                                                                     relief devices, and    duty vans are not
                                                                     unique fittings. For   altered by a
                                                                     connections with       secondary or
                                                                     refrigerant            tertiary
                                                                     containers for use     manufacturer.
                                                                     in professional       Consistent with EPA's
                                                                     servicing, use         Significant New Use
                                                                     fittings must be       Rule for
                                                                     consistent with SAE    HFO[hyphen]1234yf
                                                                     J2844.6 7 For          under the Toxic
                                                                     connections with       Substances Control
                                                                     small refrigerant      Act, commercial
                                                                     cans for consumer or   users or consumers
                                                                     professional use,      can only recharge
                                                                     use fittings must      MVAC systems with
                                                                     have a diameter of     HFO[hyphen]1234yf
                                                                     0.5 inches, a thread   where the original
                                                                     pitch of 16 thread     charging of the
                                                                     per inch, and a left   system with
                                                                     thread direction,      HFO[hyphen]1234yf
                                                                     consistent with SAE    was done by the
                                                                     J2844.                 original equipment
                                                                    (2) Manufacturers       manufacturer.
                                                                     must conduct Failure
                                                                     Mode and Effect
                                                                     Analysis (FMEA) as
                                                                     provided in SAE
                                                                     J1739.5 7
                                                                     Manufacturers must
                                                                     keep the FMEA on
                                                                     file for at least
                                                                     three years from the
                                                                     date of creation.
Motor vehicle air conditioning  HFO[hyphen]1234y  Acceptable        As of June 3, 2022:    Additional training
 (newly manufactured nonroad     f.                subject to use   (1) Systems must        for service
 agricultural tractors with                        conditions.       adhere to all of the   technicians
 greater than 40 horsepower).                                        safety requirements    recommended.
                                                                     of SAE J639,4 7       HFO[hyphen]1234yf is
                                                                     including              also known as
                                                                     requirements for a     2,3,3,3-tetrafluoro-
                                                                     flammable              prop-1-ene (CAS No.
                                                                     refrigerant warning    754-12-1).
                                                                     label, high-pressure  Consistent with EPA's
                                                                     compressor cutoff      Significant New Use
                                                                     switch and pressure    Rule for
                                                                     relief devices, and    HFO[hyphen]1234yf
                                                                     unique fittings. For   under the Toxic
                                                                     connections with       Substances Control
                                                                     refrigerant            Act, commercial
                                                                     containers for use     users or consumers
                                                                     in professional        can only recharge
                                                                     servicing, use         MVAC systems with
                                                                     fittings must be       HFO[hyphen]1234yf
                                                                     consistent with SAE    where the original
                                                                     J2844.6 7 For          charging of the
                                                                     connections with       system with
                                                                     small refrigerant      HFO[hyphen]1234yf
                                                                     cans for consumer or   was done by the
                                                                     professional use,      original equipment
                                                                     use fittings must      manufacturer.
                                                                     have a diameter of
                                                                     0.5 inches, a thread
                                                                     pitch of 16 thread
                                                                     per inch, and a left
                                                                     thread direction,
                                                                     consistent with SAE
                                                                     J2844.
                                                                    (2) Manufacturers
                                                                     must conduct Failure
                                                                     Mode and Effect
                                                                     Analysis (FMEA) as
                                                                     provided in SAE
                                                                     J1739.5 7
                                                                     Manufacturers must
                                                                     keep the FMEA on
                                                                     file for at least
                                                                     three years from the
                                                                     date of creation.
Motor vehicle air conditioning  HFO[hyphen]1234y  Acceptable        As of June 3, 2022:    Additional training
 (newly manufactured nonroad     f.                subject to use   (1) HFO[hyphen]1234yf   for service
 self-propelled agricultural                       conditions.       MVAC systems must      technicians
 machinery).                                                         adhere to all of the   recommended.
                                                                     safety requirements   HFO[hyphen]1234yf is
                                                                     of SAE J639,4 7        also known as
                                                                     including              2,3,3,3-tetrafluoro-
                                                                     requirements for a     prop-1-ene (CAS No.
                                                                     flammable              754-12-1).
                                                                     refrigerant warning   Consistent with EPA's
                                                                     label, high-pressure   Significant New Use
                                                                     compressor cutoff      Rule for
                                                                     switch and pressure    HFO[hyphen]1234yf
                                                                     relief devices, and    under the Toxic
                                                                     unique fittings. For   Substances Control
                                                                     connections with       Act commercial users
                                                                     refrigerant            or consumers can
                                                                     containers for use     only recharge MVAC
                                                                     in professional        systems with
                                                                     servicing, use         HFO[hyphen]1234yf
                                                                     fittings must be       where the original
                                                                     consistent with SAE    charging of the
                                                                     J28446 7 For           system with
                                                                     connections with       HFO[hyphen]1234yf
                                                                     small refrigerant      was done by the
                                                                     cans for consumer or   original equipment
                                                                     professional use,      manufacturer.
                                                                     use fittings must
                                                                     have a diameter of
                                                                     0.5 inches, a thread
                                                                     pitch of 16 thread
                                                                     per inch, and a left
                                                                     thread direction,
                                                                     consistent with SAE
                                                                     J2844.
                                                                    (2) Manufacturers
                                                                     must conduct Failure
                                                                     Mode and Effect
                                                                     Analysis (FMEA) as
                                                                     provided in SAE
                                                                     J1739.5 7
                                                                     Manufacturers must
                                                                     keep the FMEA on
                                                                     file for at least
                                                                     three years from the
                                                                     date of creation.

[[Page 26295]]

 
Motor vehicle air conditioning  HFO[hyphen]1234y  Acceptable        As of June 3, 2022:    Additional training
 (newly manufactured nonroad     f.                subject to use   (1) HFO[hyphen]1234yf   for service
 compact equipment).                               conditions.       MVAC systems must      technicians
                                                                     adhere to all of the   recommended.
                                                                     safety requirements   HFO[hyphen]1234yf is
                                                                     of SAE J639,4 7        also known as
                                                                     including              2,3,3,3-tetrafluoro-
                                                                     requirements for a     prop-1-ene (CAS No.
                                                                     flammable              754-12-1).
                                                                     refrigerant warning   Consistent with EPA's
                                                                     label, high-pressure   Significant New Use
                                                                     compressor cutoff      Rule for
                                                                     switch and pressure    HFO[hyphen]1234yf
                                                                     relief devices, and    under the Toxic
                                                                     unique fittings. For   Substances Control
                                                                     connections with       Act (80 FR 37166,
                                                                     refrigerant            June 30, 2015),
                                                                     containers for use     commercial users or
                                                                     in professional        consumers can only
                                                                     servicing, use         recharge MVAC
                                                                     fittings must be       systems with
                                                                     consistent with SAE    HFO[hyphen]1234yf
                                                                     J2844.6 7 For          where the original
                                                                     connections with       charging of the
                                                                     small refrigerant      system with
                                                                     cans for consumer or   HFO[hyphen]1234yf
                                                                     professional use,      was done by the
                                                                     use fittings must      original equipment
                                                                     have a diameter of     manufacturer.
                                                                     0.5 inches, a thread
                                                                     pitch of 16 thread
                                                                     per inch, and a left
                                                                     thread direction,
                                                                     consistent with SAE
                                                                     J2844).
                                                                    (2) Manufacturers
                                                                     must conduct Failure
                                                                     Mode and Effect
                                                                     Analysis (FMEA) as
                                                                     provided in SAE
                                                                     J1739.5 7
                                                                     Manufacturers must
                                                                     keep the FMEA on
                                                                     file for at least
                                                                     three years from the
                                                                     date of creation.
Motor vehicle air conditioning  HFO[hyphen]1234y  Acceptable        As of June 3, 2022:    Additional training
 (newly manufactured nonroad     f.                subject to use   (1) HFO[hyphen]1234yf   for service
 construction, forestry, and                       conditions.       MVAC systems must      technicians
 mining equipment).                                                  adhere to all of the   recommended.
                                                                     safety requirements   HFO[hyphen]1234yf is
                                                                     of SAE J639,4 7        also known as
                                                                     including              2,3,3,3-tetrafluoro-
                                                                     requirements for a     prop-1-ene (CAS No.
                                                                     flammable              754-12-1).
                                                                     refrigerant warning   Consistent with EPA's
                                                                     label, high-pressure   Significant New Use
                                                                     compressor cutoff      Rule for
                                                                     switch and pressure    HFO[hyphen]1234yf
                                                                     relief devices, and    under the Toxic
                                                                     unique fittings. For   Substances Control
                                                                     connections with       Act, commercial
                                                                     refrigerant            users or consumers
                                                                     containers for use     can only recharge
                                                                     in professional        MVAC systems with
                                                                     servicing, use         HFO[hyphen]1234yf
                                                                     fittings must be       where the original
                                                                     consistent with SAE    charging of the
                                                                     J2844.6 7 For          system with
                                                                     connections with       HFO[hyphen]1234yf
                                                                     small refrigerant      was done by the
                                                                     cans for consumer or   original equipment
                                                                     professional use,      manufacturer.
                                                                     use fittings must
                                                                     have a diameter of
                                                                     0.5 inches, a thread
                                                                     pitch of 16 thread
                                                                     per inch, and a left
                                                                     thread direction,
                                                                     consistent with SAE
                                                                     J2844.
                                                                    (2) Manufacturers
                                                                     must conduct Failure
                                                                     Mode and Effect
                                                                     Analysis (FMEA) as
                                                                     provided in SAE
                                                                     J1739.5 7
                                                                     Manufacturers must
                                                                     keep the FMEA on
                                                                     file for at least
                                                                     three years from the
                                                                     date of creation.
Motor vehicle air conditioning  HFO[hyphen]1234y  Acceptable        As of June 3, 2022:    Additional training
 (newly manufactured nonroad     f.                subject to use   (1) HFO[hyphen]1234yf   for service
 commercial utility vehicles).                     conditions.       MVAC systems must      technicians
                                                                     adhere to all of the   recommended.
                                                                     safety requirements   HFO[hyphen]1234yf is
                                                                     of SAE J639,4 7        also known as
                                                                     including              2,3,3,3-tetrafluoro-
                                                                     requirements for a     prop-1-ene (CAS No.
                                                                     flammable              754-12-1).
                                                                     refrigerant warning   Consistent with EPA's
                                                                     label, high-pressure   Significant New Use
                                                                     compressor cutoff      Rule for
                                                                     switch and pressure    HFO[hyphen]1234yf
                                                                     relief devices, and    under the Toxic
                                                                     unique fittings. For   Substances Control
                                                                     connections with       Act, commercial
                                                                     refrigerant            users or consumers
                                                                     containers for use     can only recharge
                                                                     in professional        MVAC systems with
                                                                     servicing, use         HFO[hyphen]1234yf
                                                                     fittings must be       where the original
                                                                     consistent with SAE    charging of the
                                                                     J2844.6 7 For          system with
                                                                     connections with       HFO[hyphen]1234yf
                                                                     small refrigerant      was done by the
                                                                     cans for consumer or   original equipment
                                                                     professional use,      manufacturer.
                                                                     use fittings must
                                                                     have a diameter of
                                                                     0.5 inches, a thread
                                                                     pitch of 16 thread
                                                                     per inch, and a left
                                                                     thread direction,
                                                                     consistent with SAE
                                                                     J2844.
                                                                    (2) Manufacturers
                                                                     must conduct Failure
                                                                     Mode and Effect
                                                                     Analysis (FMEA) as
                                                                     provided in SAE
                                                                     J1739.5 7
                                                                     Manufacturers must
                                                                     keep the FMEA on
                                                                     file for at least
                                                                     three years from the
                                                                     date of creation.
----------------------------------------------------------------------------------------------------------------
\4\ SAE, J639 NOV2020, Safety and Design Standards for Motor Vehicle Refrigerant Vapor Compression Systems,
  Revised November 2020.
\5\ SAE, J1739 JAN2021, Potential Failure Mode and Effects Analysis (FMEA) Including Design FMEA, Supplemental
  FMEA-MSR, and Process FMEA, Revised January 2021.
\6\ SAE, J2844 JAN2013, R-1234yf (HFO[hyphen]1234yf) New Refrigerant Purity and Container Requirements for Use
  in Mobile Air-Conditioning Systems, Revised January 2013.
\7\ The Director of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C.
  552(a) and 1 CFR part 51. It is available for inspection at the EPA and at the National Archives and Records
  Administration (NARA). Contact EPA at: U.S. EPA's Air and Radiation Docket; EPA West Building, Room 3334, 1301
  Constitution Ave. NW, Washington DC, 202-566-1742. For information on the availability of this material at
  NARA, email [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.
  Available from SAE International (SAE): SAE Customer Service, 400 Commonwealth Drive, Warrendale, PA 15096-
  0001; 1-877-606-7323 in the United States or 724-776-4970 outside the United States or in Canada; website:
  https://www.sae.org/standards.

* * * * *

[FR Doc. 2022-08923 Filed 5-3-22; 8:45 am]
BILLING CODE 6560-50-P