[Federal Register Volume 73, Number 198 (Friday, October 10, 2008)]
[Proposed Rules]
[Pages 60432-60461]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-23373]



[[Page 60431]]

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

Part III





Environmental Protection Agency





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



40 CFR Part 63



National Emission Standards for Hazardous Air Pollutant Emissions: 
Group I Polymers and Resins; Marine Vessel Loading Operations; Mineral 
Wool Production; Pharmaceuticals Production; and Printing and 
Publishing Industry; Proposed Rule

  Federal Register / Vol. 73, No. 198 / Friday, October 10, 2008 / 
Proposed Rules  

[[Page 60432]]


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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2008-0008; FRL-8724-5]
RIN 2060-AO91


National Emission Standards for Hazardous Air Pollutant 
Emissions: Group I Polymers and Resins (Epichlorohydrin Elastomers 
Production, Hypalon\TM\ Production, Nitrile Butadiene Rubber 
Production, Polybutadiene Rubber Production, and Styrene Butadiene 
Rubber and Latex Production); Marine Vessel Loading Operations; Mineral 
Wool Production; Pharmaceuticals Production; and Printing and 
Publishing Industry

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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

SUMMARY: This proposed action requests public comment on the residual 
risk and technology reviews for nine industrial source categories 
regulated by five national emission standards for hazardous air 
pollutants. The five national emission standards and nine source 
categories include: National Emissions Standards for Group I Polymers 
and Resins (Epichlorohydrin Elastomers Production, HypalonTM 
Production, Nitrile Butadiene Rubber Production, Polybutadiene Rubber 
Production, and Styrene Butadiene Rubber and Latex Production); 
National Emission Standards for Marine Vessel Loading Operations; 
National Emission Standards for Hazardous Air Pollutants for Mineral 
Wool Production; National Emission Standards for Pharmaceuticals 
Production; and National Emission Standards for the Printing and 
Publishing Industry. The underlying national emission standards that 
are under review in this action limit and control hazardous air 
pollutants.
    We are proposing that no revisions to the five national emission 
standards regulating these nine source categories are required at this 
time under section 112(f)(2) or 112(d)(6) of the Clean Air Act.

DATES: Comments. Comments must be received on or before November 24, 
2008.
    Public Hearing.  If anyone contacts EPA requesting to speak at a 
public hearing by October 20, 2008, a public hearing will be held on 
October 27, 2008.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2008-0008, by one of the following methods:
     http://www.regulations.gov. Follow the on-line 
instructions for submitting comments.
     E-mail: [email protected].
     Fax: (202) 566-9744.
     Mail: U.S. Postal Service, send comments to: EPA Docket 
Center (2822T), Docket ID No. EPA-HQ-OAR-2008-0008, 1200 Pennsylvania 
Avenue, NW., Washington, DC 20460. Please include a total of two 
copies.
     Hand Delivery: In person or by courier, deliver comments 
to: EPA Docket Center (2822T), EPA West Building, Room 3334, 1301 
Constitution Ave., NW., Washington, DC 20004. Please include a total of 
two copies. Such deliveries are only accepted during the Docket's 
normal hours of operation, and special arrangements should be made for 
deliveries of boxed information. We request that a separate copy of 
each public comment also be sent to the contact person listed below 
(see FOR FURTHER INFORMATION CONTACT).
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2008-0008. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
confidential business information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through http://www.regulations.gov or e-mail. The http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through http://www.regulations.gov, your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket, visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. 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, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the EPA Docket Center, 
Docket ID No. EPA-HQ-OAR-2008-0008, EPA, West Building, Room 3334, 1301 
Constitution Avenue, NW., Washington, DC. The Public Reading Room is 
open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding 
legal holidays. The telephone number for the Public Reading Room is 
(202) 566-1744, and the telephone number for the EPA Docket Center is 
(202) 566-1742.

FOR FURTHER INFORMATION CONTACT:  For questions about this proposed 
action, contact Ms. Mary Tom Kissell, Office of Air Quality Planning 
and Standards, Sector Policies and Programs Division, Coatings and 
Chemicals Group (E143-01), U.S. Environmental Protection Agency, 
Research Triangle Park, NC 27711; telephone number: (919) 541-4516; fax 
number: (919) 685-3219; and e-mail address: [email protected]. For 
specific information regarding the modeling methodology, contact Ms. 
Elaine Manning, Office of Air Quality Planning and Standards, Health 
and Environmental Impacts Division, Sector Based Assessment Group 
(C539-02), U.S. Environmental Protection Agency, Research Triangle 
Park, NC 27711; telephone number: (919) 541-5499; fax number: (919) 
541-0840; and e-mail address: [email protected]. For information 
about the applicability of these five national emission standards for 
hazardous air pollutants (NESHAP) to a particular entity, contact the 
appropriate person listed in Table 1 to this preamble.

[[Page 60433]]



       Table 1--List of EPA Contacts for Group I Polymers and Resins, Marine Vessel Loading, Mineral Wool,
                                  Pharmaceuticals, and Printing and Publishing
----------------------------------------------------------------------------------------------------------------
                    NESHAP for:                            OECA contact \1\              OAQPS contact \2\
----------------------------------------------------------------------------------------------------------------
Polymers and Resins Production, Group I...........  Scott Throwe, (202) 564-7013,  David Markwordt, (919) 541-
                                                     [email protected].          0837,
                                                                                    [email protected].
Marine Vessel Loading Operations..................  Maria Malave, (202) 564-7027,  David Markwordt, (919) 541-
                                                     [email protected].          0837,
                                                                                    [email protected].
Mineral Wool Production...........................  Scott Throwe, (202) 564-7013,  Jeff Telander, (919) 541-
                                                     [email protected].          5427, [email protected].
Pharmaceuticals Production........................  Marcia Mia, (202) 564-7042,    Randy McDonald, (919) 541-
                                                     [email protected].            5402,
                                                                                    [email protected].
Printing and Publishing Industry..................  Len Lazarus, (202) 564-6369,   David Salman, (919) 541-0859,
                                                     [email protected].       [email protected].
----------------------------------------------------------------------------------------------------------------
\1\ OECA stands for EPA's Office of Enforcement and Compliance Assurance.
\2\ OAQPS stands for EPA's Office of Air Quality Planning and Standards.


SUPPLEMENTARY INFORMATION: Regulated Entities. The nine regulated 
industrial source categories that are the subject of this proposal are 
listed in Table 2 to this preamble. Table 2 is not intended to be 
exhaustive, but rather provides a guide for readers regarding entities 
likely to be affected by the proposed action for the source categories 
listed. These standards, and any changes considered in this rulemaking, 
would be directly applicable to sources as a Federal program. Thus, 
Federal, State, local, and tribal government entities are not affected 
by this proposed action. The regulated categories affected by this 
action include:

          Table 2--NESHAP for Nine Industrial Source Categories
------------------------------------------------------------------------
                                                    NAICS \1\   MACT \2\
                     Category                          code       code
------------------------------------------------------------------------
Epichlorohydrin Elastomers Production.............     325212       1311
Hypalon \TM\ Production...........................     325212       1315
Nitrile Butadiene Rubber Production...............     325212       1321
Polybutadiene Rubber Production...................     325212       1325
Styrene Butadiene Rubber and Latex Production.....     325212       1339
Marine Vessel Loading.............................       4883       0603
Mineral Wool Production...........................     327993       0409
Pharmaceuticals Production........................       3254       1201
Printing and Publishing Industry..................      32311      0714
------------------------------------------------------------------------
\1\ North American Industry Classification System.
\2\ Maximum Achievable Control Technology.

    To determine whether your facility would be affected, you should 
examine the applicability criteria in the appropriate NESHAP. If you 
have any questions regarding the applicability of any of these NESHAP, 
please contact the appropriate person listed in Table 1 of this 
preamble in the preceding FOR FURTHER INFORMATION CONTACT section.
    Submitting Comments/CBI. Direct your comments to Docket ID No. EPA-
HQ-OAR-2008-0008. If commenting on changes to the residual risk and 
technology reviews (RTR) database, please submit your comments in the 
format described in sections III and IV of this preamble. Do not submit 
CBI to EPA through http://www.regulations.gov or e-mail. Instead, send 
or deliver information identified as CBI only to the following address: 
Mr. Roberto Morales, OAQPS Document Control Officer (C404-02), U.S. 
Environmental Protection Agency, Office of Air Quality Planning and 
Standards, Research Triangle Park, NC 27711, Attention Docket ID No. 
EPA-HQ-OAR-2008-0008. Clearly mark the part or all of the information 
that you claim to be CBI. For CBI information on a disk or CD-ROM that 
you mail to Mr. Morales, mark the outside of the disk or CD-ROM as CBI 
and then identify electronically within the disk or CD-ROM the specific 
information that is claimed as CBI.
    In addition to one complete version of the comment that includes 
information claimed as CBI, a copy of the comment that does not contain 
the information claimed as CBI must be submitted for inclusion in the 
public docket. If you submit a CD-ROM or disk that does not contain 
CBI, mark the outside of the disk or CD-ROM clearly that it does not 
contain CBI. Information not marked as CBI will be included in the 
public docket and EPA's electronic public docket without prior notice.
    If you have any questions about CBI or the procedures for claiming 
CBI, please consult the person identified in the FOR FURTHER 
INFORMATION CONTACT section. Information marked as CBI will not be 
disclosed except in accordance with procedures set forth in 40 CFR part 
2.
    Worldwide Web (WWW). In addition to being available in the docket, 
an electronic copy of this proposed action will also be available on 
the WWW through the Technology Transfer Network (TTN). Following 
signature, a copy of the proposed action will be posted on the TTN's 
policy and guidance page for newly proposed or promulgated rules at the 
following address: http://www.epa.gov/ttn/oarpg/. The TTN provides 
information and technology exchange in various areas of air pollution 
control.
    As discussed in more detail in sections III and IV of this 
preamble, additional information is available on the RTR Phase II Web 
page at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. This information 
includes source category descriptions and detailed emissions and other 
data that were used as inputs to the risk assessments.
    Public Hearing. If a public hearing is held, it will begin at 10 
a.m. on November 10, 2008 and will be held at EPA's campus in Research 
Triangle Park, North Carolina, or at an alternate facility nearby. 
Persons interested in presenting oral testimony or inquiring as to 
whether a public hearing is to be held should contact Ms. Mary Tom 
Kissell, Office of Air Quality Planning and Standards, Sector Policies 
and Programs Division, Coatings and Chemicals Group (E143-01), U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711; 
telephone number: (919) 541-4516.
    Outline. The information presented in this preamble is organized as 
follows:

I. Background
    A. What is the statutory authority for this action?
    B. Overview of RTR
    C. Overview of the Five NESHAP
    D. How did we estimate risk posed by the nine source categories?

[[Page 60434]]

    E. What are the results of the risk assessment?
    F. What are our proposed decisions on acceptability and ample 
margin of safety?
    G. What are the results of the technology review?
II. Proposed Action
    A. What is the rationale for our proposed action under CAA 
section 112(f)?
    B. What is the rationale for our proposed action under CAA 
section 112(d)(6)?
III. Request for Comments
IV. How do I submit suggested data corrections?
V. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and 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 Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations 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

I. Background

A. What is the statutory authority for this action?

    Section 112 of the CAA establishes a two-stage regulatory process 
to address emissions of hazardous air pollutants (HAP) from stationary 
sources. In the first stage, after EPA has identified categories of 
sources emitting one or more of the HAP listed in section 112(b) of the 
CAA, section 112(d) of the CAA calls for us to promulgate NESHAP for 
those sources. ``Major sources'' are those that emit or have the 
potential to emit any single HAP at a rate of 10 tons or more per year 
of a single HAP or 25 tons per year of any combination of HAP. For 
major sources, these technology-based standards must reflect the 
maximum degree of emission reductions of HAP achievable (after 
considering cost, energy requirements, and non-air quality health and 
environmental impacts) and are commonly referred to as maximum 
achievable control technology (MACT) standards.
    The MACT ``floor'' is the minimum control level allowed for MACT 
standards promulgated under section 112(d)(3). For new sources, the 
MACT floor cannot be less stringent than the emission control that is 
achieved in practice by the best-controlled similar source. The MACT 
standards for existing sources can be less stringent than standards for 
new sources, but they cannot be less stringent than the average 
emission limitation achieved by the best-performing 12 percent of 
existing sources in the category or subcategory (or the best-performing 
five sources for categories or subcategories with fewer than 30 
sources). In developing MACT standards, we must also consider control 
options that are more stringent than the floor. We may establish 
standards more stringent than the floor based on the consideration of 
the cost of achieving the emissions reductions, any non-air quality 
health and environmental impacts, and energy requirements.
    EPA is then required to review these technology-based standards and 
to revise them ``as necessary (taking into account developments in 
practices, processes, and control technologies)'' no less frequently 
than every 8 years, under CAA section 112(d)(6). In this proposed rule, 
we are publishing the results of our 8-year technology review for the 
nine industrial source categories listed in Table 3, which we have 
collectively termed ``Group 2A.''
    The second stage in standard-setting focuses on reducing any 
remaining ``residual'' risk according to CAA section 112(f). This 
provision requires, first, that EPA prepare a Report to Congress 
discussing (among other things) methods of calculating risk posed (or 
potentially posed) by sources after implementation of the MACT 
standards, the public health significance of those risks, the means and 
costs of controlling them, actual health effects to persons in 
proximity of emitting sources, and recommendations as to legislation 
regarding such remaining risk. EPA prepared and submitted this report 
(Residual Risk Report to Congress, EPA-453/R-99-001) in March 1999. 
Congress did not act in response to the report, thereby triggering 
EPA's obligation under CAA section 112(f)(2) to analyze and address 
residual risk.
    CAA section 112(f)(2) requires us to determine for source 
categories subject to certain CAA section 112(d) standards whether the 
emissions limitations provide an ample margin of safety to protect 
public health. If the MACT standards for HAP ``classified as a known, 
probable, or possible human carcinogen do not reduce lifetime excess 
cancer risks to the individual most exposed to emissions from a source 
in the category or subcategory to less than 1-in-1 million,'' EPA must 
promulgate residual risk standards for the source category (or 
subcategory) as necessary to provide an ample margin of safety to 
protect public health. In doing so, EPA may adopt standards equal to 
existing MACT standards (NRDC v. EPA, No. 07-1053, slip op. at 11, D.C. 
Cir., decided June 6, 2008). EPA must also adopt more stringent 
standards, if necessary, to prevent an adverse environmental effect,\1\ 
but must consider cost, energy, safety, and other relevant factors in 
doing so. Section 112(f)(2) of the CAA expressly preserves our use of a 
two-step process for developing standards to address any residual risk 
and our interpretation of ``ample margin of safety'' developed in the 
National Emission Standards for Hazardous Air Pollutants: Benzene 
Emissions from Maleic Anhydride Plants, Ethylbenzene/Styrene Plants, 
Benzene Storage Vessels, Benzene Equipment Leaks, and Coke By-Product 
Recovery Plants (Benzene NESHAP) (54 FR 38044, September 14, 1989).
---------------------------------------------------------------------------

    \1\ ``Adverse environmental effect'' is defined in CAA section 
112(a)(7) as any significant and widespread adverse effect, which 
may be reasonably anticipated to wildlife, aquatic life, or natural 
resources, including adverse impacts on populations of endangered or 
threatened species or significant degradation of environmental 
qualities over broad areas.
---------------------------------------------------------------------------

    The first step in this process is the determination of acceptable 
risk. The second step provides for an ample margin of safety to protect 
public health, which is the level at which the standards are set 
(unless a more stringent standard is required to prevent, taking into 
consideration costs, energy, safety, and other relevant factors, an 
adverse environmental effect).
    The terms ``individual most exposed,'' ``acceptable level,'' and 
``ample margin of safety'' are not specifically defined in the CAA. 
However, CAA section 112(f)(2)(B) directs us to use the interpretation 
set out in the Benzene NESHAP. See also, A Legislative History of the 
Clean Air Act Amendments of 1990, volume 1, p. 877 (Senate debate on 
Conference Report). We notified Congress in the Residual Risk Report to 
Congress that we intended to use the Benzene NESHAP approach in making 
CAA section 112(f) residual risk determinations (EPA-453/R-99-001, p. 
ES-11).
    In the Benzene NESHAP, we stated as an overall objective:

    * * * in protecting public health with an ample margin of 
safety, we strive to provide maximum feasible protection against 
risks to health from hazardous air pollutants by (1) protecting the 
greatest number of persons possible to an individual lifetime risk 
level no higher than approximately 1-in-1 million; and (2) limiting 
to no higher than approximately 1-in-10 thousand [i.e., 100-in-1 
million] the estimated risk that a person

[[Page 60435]]

living near a facility would have if he or she were exposed to the 
maximum pollutant concentrations for 70 years.

    The Agency also stated that, ``The EPA also considers incidence 
(the number of persons estimated to suffer cancer or other serious 
health effects as a result of exposure to a pollutant) to be an 
important measure of the health risk to the exposed population. 
Incidence measures the extent of health risk to the exposed population 
as a whole, by providing an estimate of the occurrence of cancer or 
other serious health effects in the exposed population.'' The Agency 
went on to conclude that ``estimated incidence would be weighed along 
with other health risk information in judging acceptability.'' As 
explained more fully in our Residual Risk Report to Congress, EPA does 
not define ``rigid line[s] of acceptability,'' but considers rather 
broad objectives to be weighed with a series of other health measures 
and factors (EPA-453/R-99-001, p. ES-11). The determination of what 
represents an ``acceptable'' risk is based on a judgment of ``what 
risks are acceptable in the world in which we live'' (Residual Risk 
Report to Congress, p. 178, quoting the Vinyl Chloride decision at 824 
F.2d 1165) recognizing that our world is not risk-free.
    In the Benzene NESHAP, we stated that ``EPA will generally presume 
that if the risk to [the maximum exposed] individual is no higher than 
approximately 1 in 10 thousand, that risk level is considered 
acceptable.'' 54 FR at 38045. We discussed the maximum individual 
lifetime cancer risk as being ``the estimated risk that a person living 
near a plant would have if he or she were exposed to the maximum 
pollutant concentrations for 70 years.'' Id. We explained that this 
measure of risk ``is an estimate of the upperbound of risk based on 
conservative assumptions, such as continuous exposure for 24 hours per 
day for 70 years.'' Id. We acknowledge that maximum individual lifetime 
cancer risk ``does not necessarily reflect the true risk, but displays 
a conservative risk level which is an upperbound that is unlikely to be 
exceeded.'' Id.
    Understanding that there are both benefits and limitations to using 
maximum individual lifetime cancer risk as a metric for determining 
acceptability, we acknowledged in the 1989 Benzene NESHAP that 
``consideration of maximum individual risk * * * must take into account 
the strengths and weaknesses of this measure of risk.'' Id. 
Consequently, the presumptive risk level of 100-in-1 million (1-in-10 
thousand) provides a benchmark for judging the acceptability of maximum 
individual lifetime cancer risk, but does not constitute a rigid line 
for making that determination.
    The Agency also explained in the 1989 Benzene NESHAP the following: 
``In establishing a presumption for MIR [maximum individual cancer 
risk], rather than rigid line for acceptability, the Agency intends to 
weigh it with a series of other health measures and factors. These 
include the overall incidence of cancer or other serious health effects 
within the exposed population, the numbers of persons exposed within 
each individual lifetime risk range and associated incidence within, 
typically, a 50 kilometer (km) exposure radius around facilities, the 
science policy assumptions and estimation uncertainties associated with 
the risk measures, weight of the scientific evidence for human health 
effects, other quantified or unquantified health effects, effects due 
to co-location of facilities, and co-emission of pollutants.'' Id.
    In some cases, these health measures and factors taken together may 
provide a more realistic description of the magnitude of risk in the 
exposed population than that provided by maximum individual lifetime 
cancer risk alone.
    As explained in the Benzene NESHAP, ``[e]ven though the risks 
judged ``acceptable'' by EPA in the first step of the Vinyl Chloride 
inquiry are already low, the second step of the inquiry, determining an 
``ample margin of safety,'' again includes consideration of all of the 
health factors, and whether to reduce the risks even further. In the 
second step, EPA strives to provide protection to the greatest number 
of persons possible to an individual lifetime risk level no higher than 
approximately 1 in 1 million. In the ample margin decision, the Agency 
again considers all of the health risk and other health information 
considered in the first step. Beyond that information, additional 
factors relating to the appropriate level of control will also be 
considered, including costs and economic impacts of controls, 
technological feasibility, uncertainties, and any other relevant 
factors. Considering all of these factors, the Agency will establish 
the standard at a level that provides an ample margin of safety to 
protect the public health, as required by section 112.'' 54 FR at 
38046.

B. Overview of RTR

    We have begun to conduct the RTR for 96 MACT standards covering 174 
sources categories. In an effort to streamline the RTR process and 
focus our resources on source categories with the greatest potential 
for risk to human health and the environment, we combined source 
categories to create several groups, e.g., RTR Group 2A (which is the 
subject of this proposed rule), and decided the order in which we would 
propose each source category group. In deciding how to group source 
categories, we considered factors such as the promulgation date of the 
NESHAP, our preliminary analysis of the level of risk, completeness of 
available emissions data, complexity of the risk assessment, and 
whether we anticipated promulgating additional regulations pursuant to 
the RTR.
    In general, we are addressing source categories with the earliest 
NESHAP promulgation dates first because they have the earliest RTR due 
dates and because the 2002 National Emission Inventory (NEI) contains 
emissions data which reflect implementation of the NESHAP. 
Additionally, we are addressing lower risk source categories first 
because they typically require less effort to complete the necessary 
analysis than higher risk source categories. We expect that the higher 
risk source categories will require more time to evaluate because we 
will likely need to perform more refined risk assessments, and because 
they may have more complex issues to address, such as the emissions of 
persistent and bioaccumulative HAP. Moreover, we believe our reviews of 
the higher risk source categories will benefit from an understanding of 
the public's concerns about our RTR approaches (through the comments we 
receive on the earlier proposals).
    For the nine source categories in today's proposal for RTR Group 
2A, we have concluded that emissions levels remaining after compliance 
with the existing MACT standards: (1) Pose no unacceptable maximum 
individual cancer risks (i.e., because the MIR is less than 100-in-1 
million the risk is acceptable); (2) pose no significant chronic 
noncancer health effects (i.e., maximum individual target organ-
specific hazard index (HI) values are all less than or equal to 1); (3) 
are unlikely to result in acute adverse health effects from peak short-
term excursions; and (4) are unlikely to result in any adverse 
environmental effect. Thus, we are proposing that the existing 
standards provide an ample margin of safety to protect public health 
and prevent adverse environmental effects.
    Future RTR actions for other source categories may require changes 
to existing MACT standards to achieve the protection of public health 
with an ample margin of safety and/or to

[[Page 60436]]

prevent adverse environmental effects. Future actions may also require 
additional emission reductions pursuant to the technology review. We 
plan to conduct RTR assessments for 12 source categories (RTR Groups 2B 
and 2C, which were included in an advanced notice of proposed 
rulemaking in March 2007) and propose our findings.\2\ In addition, we 
plan to publish at least three more advanced notices of proposed 
rulemaking. We may also publish some RTR for individual MACT standards 
because of special circumstances such as court ordered deadlines. (See, 
for example, the proposed RTR for Petroleum Refineries, 72 FR 50716, 
09/04/2007.)
---------------------------------------------------------------------------

    \2\ RTR Group 2B: Oil and Natural Gas Production; Natural Gas 
Transmission; and Aerospace Operations. RTR Group 2C: Primary 
Aluminum; Polymers and Resins IV (seven source categories); and Ship 
Building.
---------------------------------------------------------------------------

C. Overview of the Five NESHAP

    The nine industrial source categories and five NESHAP that are the 
subject of this proposal are listed in Table 3 to this preamble. NESHAP 
limit and control HAP that are known or suspected to cause cancer or 
that may cause other serious human health or environmental effects. The 
NESHAP for these nine source categories generally require 
implementation of emissions reduction technologies such as combustion 
devices, recovery devices, scrubbers, and fabric filters for point 
sources and work practice and equipment standards for fugitive sources.

    Table 3--List of National Emission Standards for Hazardous Air Pollutants (NESHAP) and Industrial Source
                                     Categories Affected by Today's Proposal
----------------------------------------------------------------------------------------------------------------
                                     Source categories
         Title of NESHAP             affected by this      Promulgated rule     Compliance   NESHAP as referred
                                         proposal              reference           date      to in this preamble
----------------------------------------------------------------------------------------------------------------
NESHAP: Group I Polymers and       Epichlorohydrin       61 FR 46905 (09/05/      07/31/97  Polymers and Resins
 Resins \1\.                        Elastomers            96).                               I.
                                    Production Hypalon
                                    \TM\ Production.
                                   Nitrile Butadiene
                                    Rubber Production.
                                   Polybutadiene Rubber
                                    Production.
                                   Styrene-Butadiene
                                    Rubber and Latex
                                    Production.
National Emission Standards for    Marine Vessel         60 FR 48388 (09/19/      09/19/99  Marine Vessels.
 Marine Vessel Loading Operations.  Loading Operations.   95).
NESHAP for Mineral Wool            Mineral Wool          64 FR 29489 (06/01/      06/01/02  Mineral Wool.
 Production.                        Production.           99).
National Emission Standards for    Pharmaceuticals       63 FR 50280 (09/21/      09/21/01  Pharmaceuticals.
 Pharmaceuticals Production.        Production.           98).
National Emission Standards for    Printing/Publishing   61 FR 27131 (05/30/      05/30/99  Printing and
 the Printing and Publishing        (Surface Coating).    96).                               Publishing.
 Industry.
----------------------------------------------------------------------------------------------------------------
\1\ The Polymers and Resins I NESHAP regulates nine source categories. We are performing the RTR for five of
  these in this proposal. The four other Polymers and Resins I source categories are being addressed in a
  separate RTR rulemaking. (See National Emission Standards for Hazardous Air Pollutant Emissions: Group I
  Polymers and Resins (Polysulfide Rubber Production, Ethylene Propylene Rubber Production, Butyl Rubber
  Production, Neoprene Production); National Emission Standards for Hazardous Air Pollutants for Epoxy Resins
  Production and Non-Nylon Polyamides Production; National Emission Standards for Hazardous Air Pollutants for
  Source Categories: Generic Maximum Achievable Control Technology Standards (Acetal Resins Production and
  Hydrogen Fluoride Production), proposed on December 12, 2007, at 72 FR 70543.)

1. Polymers and Resins I
    The National Emission Standards for Hazardous Air Pollutant 
Emissions: Group I Polymers and Resins were promulgated on September 5, 
1996 (62 FR 46925). The Polymers and Resins I NESHAP applies to major 
sources and regulates HAP emissions from nine source categories. In 
this proposal, we address five of the Polymer and Resins I sources 
categories--Epichlorohydrin Elastomers Production, Hypalon \TM\ 
Production, Nitrile Butadiene Rubber Production, Polybutadiene Rubber 
Production, and Styrene Butadiene Rubber and Latex Production.
    The Polymers and Resins I NESHAP regulate HAP emissions resulting 
from the production of elastomers (i.e., synthetic rubber). An 
elastomer is a synthetic polymeric material that can stretch at least 
twice its original length and then return rapidly to approximately its 
original length when released. Elastomers are produced via a 
polymerization/copolymerization process, in which monomers undergo 
intermolecular chemical bond formation to form a very large polymer 
molecule. Generally, the production of elastomers entails four 
processes: (1) Raw material (i.e., solvent) storage and refining; (2) 
polymer formation in a reactor (either via the solution process, where 
monomers are dissolved in an organic solvent, or the emulsion process, 
where monomers are dispersed in water using a soap solution); (3) 
stripping and material recovery; and (4) finishing (i.e., blending, 
aging, coagulation, washing, and drying).
    Sources of HAP emissions from elastomers production include raw 
material storage vessels, front-end process vents, back-end process 
operations, wastewater operations, and equipment leaks. The ``front-
end'' processes include pre-polymerization, reaction, stripping, and 
material recovery operations; and the process ``back-end'' includes all 
operations after stripping (predominately drying and finishing). 
Typical control devices used to reduce organic HAP emissions from 
front-end process vents include flares, incinerators, absorbers, carbon 
adsorbers, and condensers. In addition, hydrochloric acid formed when 
chlorinated organic compounds are combusted are controlled using 
scrubbers. Emissions from storage vessels are controlled by floating 
roofs or by routing them to a control device. While emissions from 
back-end process operations can be controlled with

[[Page 60437]]

control devices such as incinerators, the most common method of 
reducing these emissions is the pollution prevention method of reducing 
the amount of residual HAP that is contained in the raw product going 
to the back-end operations. Emissions from wastewater are controlled by 
a variety of methods, including equipment modifications (e.g., fixed 
roofs on storage vessels and oil water separators; covers on surface 
impoundments, containers, and drain systems), treatment to remove the 
HAP (steam stripping, biological treatment), control devices, and work 
practices. Emissions from equipment leaks are typically reduced by leak 
detection and repair work practice programs, and in some cases, by 
equipment modifications.
    Each of the five Polymers and Resins I source categories addressed 
in this proposal are discussed further below.
a. Epichlorohydrin Elastomers Production
    Epichlorohydrin elastomers are prepared from the polymerization or 
copolymerization of epichlorohydrin or other monomers. Epichlorohydrin 
elastomers are produced by a solution polymerization process, typically 
using toluene as the solvent in the reaction. The main epichlorohydrin 
elastomers are polyepichlorohydrin, epi-ethylene oxide (EO) copolymer, 
epi-allyl glycidyl ether (AGE) copolymer, and epi-EO-AGE terpolymer. 
Epichlorohydrin elastomers are widely used in the automotive industry.
    We identified one epichlorohydrin elastomers production facility 
currently subject to the Polymers and Resins I NESHAP. This facility 
produces epichlorohydrin elastomers primarily, but the plant site also 
has equipment regulated by other NESHAP, which have been or will be 
addressed in separate RTR rulemaking actions.
    Toluene accounts for the majority of the HAP emissions from the 
epichlorohydrin production processes at this facility (approximately 
105 tons per year (TPY) and 99 percent of the total HAP emissions by 
mass). This facility also reported relatively small emissions of 
epichlorohydrin and ethylene oxide. The majority of HAP emissions are 
from back-end process vents (approximately 75 percent of the total HAP 
by mass). We estimate that the MACT allowable emissions (i.e., the 
maximum emission levels allowed if in compliance with the NESHAP) from 
this source category are approximately equal to the reported, actual 
emissions.\3\
---------------------------------------------------------------------------

    \3\ Our analysis of the impacts of the worst case MACT allowable 
emissions as compared to reported actual emissions for each of the 
nine source categories is discussed in more detail in ``Estimation 
of MACT Allowable Emission Levels and Associated Risks and Impacts 
for the RTR Group 2A Source Categories.''.
---------------------------------------------------------------------------

b. Hypalon \TM\ Production
    Hypalon,\TM\ or chlorosulfonated polyethylene, is a synthetic 
rubber produced by reacting polyethylene with chlorine and sulfur 
dioxide, transforming the thermoplastic polyethylene into a vulcanized 
elastomer. The reaction is conducted in a solvent reaction medium 
containing carbon tetrachloride. These elastomers are commonly used in 
wire insulation and jacketing, automotive components, adhesives, and 
protective coatings.
    We identified one Hypalon \TM\ production facility currently 
subject to the Polymers and Resins I NESHAP. The plant site for this 
facility also has other HAP-emitting sources which are regulated under 
separate NESHAP, including Marine Vessel Loading Operations, 40 CFR 
part 63, subpart Y. Marine Vessel Loading Operations are addressed 
separately in this proposed rule, but RTR for the other NESHAP have 
been or will be addressed in separate rulemaking actions.
    Carbon tetrachloride accounts for the majority of the HAP emissions 
from the Hypalon \TM\ production processes at this facility 
(approximately 22 TPY and 71 percent of the total HAP emissions by 
mass). This facility also reported relatively small emissions of 
chlorine, chloroform, and hydrochloric acid. The majority of HAP 
emissions are from front-end process vents (approximately 63 percent of 
the total HAP by mass) and back-end process operations (approximately 
33 percent of the total HAP by mass). We estimate that MACT allowable 
emissions from this source category are approximately equal to 
reported, actual emissions.
c. Nitrile Butadiene Rubber Production
    Nitrile butadiene rubber (NBR) is a copolymer of 1,3-butadiene and 
acrylonitrile, and the NBR production source category includes any 
facility that polymerizes 1,3-butadiene and acrylonitrile. While NBR is 
the primary product at these facilities, styrene-butadiene rubber can 
also be produced as a minor product by substituting styrene for 
acrylonitrile as a monomer. Depending on its specific composition, NBR 
can be resistant to oil and chemicals, a property that facilitates its 
use in disposable gloves, hoses, seals, and a variety of automotive 
applications.
    We identified four NBR production facilities currently subject to 
the Polymers and Resins I NESHAP. Two of these facilities are at plant 
sites that also have operations which produce styrene-butadiene rubber 
and latex, another Polymers and Resins I source category. The styrene-
butadiene rubber and latex processes and emissions are addressed 
separately in today's proposed action under the Styrene Butadiene 
Rubber and Latex source category. Some of these facilities also have 
other HAP-emitting sources that are regulated under separate NESHAP, 
which have been or will be addressed in separate RTR rulemaking 
actions.
    Styrene, 1,3-butadiene, and acrylonitrile account for the majority 
of the HAP emissions from this source category (approximately 46 TPY 
and over 99 percent of the total HAP emissions by mass). The facilities 
in this source category also reported relatively small emissions of 
carbon disulfide. The majority of HAP emissions are from back-end 
process operations (approximately 43 percent of the total HAP by mass) 
and front-end process vents (approximately 34 percent of the total HAP 
by mass) for this source category. However, the emissions from one 
facility were not included in this estimation of emissions by source 
type, as it was not possible to positively discern which types of 
emission sources were responsible for emissions from this facility in 
all instances. Based on the emissions release characteristics for this 
facility, we estimate that of the facility's 48 TPY of HAP emissions, 
the majority are from back-end process operations and equipment leaks 
(approximately 58 and 23 percent by mass, respectively). We estimate 
that MACT allowable emissions from this source category are 
approximately equal to reported, actual emissions.
d. Polybutadiene Rubber Production
    Polybutadiene rubber (PBR) is a homopolymer of 1,3-butadiene (i.e., 
1,3-butadiene is the only monomer used in the production of this 
polymer). While both the solution and emulsion polymerization processes 
can be used to produce PBR, all currently operating facilities in the 
United States use a solution process. In the solution process, the 
reaction is conducted in an organic solvent (hexane, toluene, or a non-
HAP organic solvent), which helps to dissipate heat generated by the 
reaction and control the reaction rate. While PBR is the primary 
product at these facilities, styrene-butadiene rubber can also be 
produced as a minor product by adding styrene as a monomer. Most of the 
PBR manufactured in the United States is used in the production of 
tires in the construction of the tread and

[[Page 60438]]

sidewalls. PBR is also used as a modifier in the production of other 
polymers and resins (e.g., polystyrene).
    We identified five PBR production facilities currently subject to 
the Polymers and Resins I NESHAP. Some of these facilities are located 
at plant sites that also have other HAP-emitting sources regulated 
under separate NESHAP, which have been or will be addressed in separate 
RTR actions.
    Three of the PBR production facilities use hexane as the solvent in 
their solution process, one facility uses toluene as its solvent, and 
the fifth uses a non-HAP organic solvent. Overall, hexane accounts for 
the majority of the HAP emissions from this source category 
(approximately 1,455 TPY and 72 percent of the total HAP emissions by 
mass). The facilities in this source category also reported substantive 
emissions of styrene and 1,3-butadiene and relatively minor quantities 
of three other HAP. The majority of HAP emissions are from back-end 
process operations (approximately 73 percent of the total HAP by mass). 
We estimate that MACT allowable emissions from this source category 
could be as high as five times the actual emissions.
e. Styrene Butadiene Rubber and Latex Production
    Styrene butadiene rubber and latex are elastomers prepared from 
styrene and butadiene monomer units. The source category is divided 
into three subcategories due to technical process and HAP emission 
differences: (1) The production of styrene butadiene rubber by 
emulsion, (2) the production of styrene butadiene rubber by solution, 
and (3) the production of styrene butadiene latex. Styrene butadiene 
rubber is coagulated and dried to produce a solid product, while latex 
is a liquid product. For both styrene butadiene rubber processes, the 
monomers used are styrene and butadiene; either process can be 
conducted as a batch or a continuous process. These elastomers are 
commonly used in tires and tire-related products.
    We identified two styrene butadiene rubber production facilities 
using the emulsion process and 12 styrene butadiene rubber latex 
production facilities currently subject to the Polymers and Resins I 
NESHAP. Other than the polybutadiene plants that produce styrene 
butadiene rubber as a minor product, we did not identify any styrene 
butadiene rubber produced in a solution process. Two of these 
facilities are located at plant sites that also have operations which 
produce NBR, another Polymers and Resins I source category. The NBR 
processes and emissions are addressed separately in this proposed 
action under the Nitrile Butadiene Rubber source category. Some of 
these facilities are located at plant sites that also have other HAP-
emitting sources regulated under separate NESHAP, which have been or 
will be addressed in separate RTR actions.
    Overall, styrene accounts for the majority of the HAP emissions 
from these facilities (approximately 276 TPY and 90 percent of the 
total HAP emissions by mass). These facilities also reported relatively 
small emissions of 13 other HAP. The majority of HAP emissions are from 
back-end process operations (approximately 80 percent of the total HAP 
by mass). We estimate that MACT allowable emissions from this source 
category could be as high as four times the actual emissions.
2. Marine Vessels
    The National Emission Standards for Marine Vessel Loading 
Operations were promulgated on September 19, 1995 (60 FR 48388). The 
Marine Vessel Loading Operations NESHAP applies to major sources and 
regulates HAP emissions from: Land-based terminals, off-shore 
terminals, and the Alyeska Pipeline Service Company's Valdez Marine 
Terminal.
    Marine vessel loading operations are facilities that load and 
unload liquid commodities in bulk, such as crude oil, gasoline, and 
other fuels, and some chemicals and solvent mixtures. The cargo is 
pumped from the terminal's large, above-ground storage tanks through a 
network of pipes and into a storage compartment (tank) on the vessel. 
Emissions occur as vapors are displaced from the tank as it is being 
filled. Most marine tank vessel loading operations are associated with 
petroleum refineries, synthetic organic chemical manufacturers, or are 
independent terminals.
    The primary emission sources of displaced vapors at marine vessel 
loading operations include open tank hatches and overhead vent systems. 
Other possible emission points are hatch covers or domes, pressure-
vacuum relief valves, seals, and vents. Emissions may also occur during 
ballasting (i.e., the process of drawing ballast as water into a cargo 
hold). The NESHAP requires control of all displaced vapors that occur 
during product loading. Typical control devices used to reduce HAP 
emissions include vapor collection systems routed to combustion or 
recovery devices, such as flares, incinerators, absorbers, carbon 
adsorbers, and condensers.
    Additional data indicate that approximately 800 terminals load HAP-
containing organic liquids. An unknown fraction of these are 
containerized liquids that are not subject to the Marine Vessel Loading 
Operations NESHAP. Therefore, we estimate up to 800 facilities may be 
subject to the Marine Vessel Loading Operations NESHAP. However, data 
in the 2002 NEI were available for only 135 facilities and our analyses 
are based on these 135 modeled facilities. We believe the 135 modeled 
facilities are representative of the source category because we expect 
that generally the same HAP, in the same range of quantities, are 
emitted from the 135 modeled facilities as are emitted from rest of the 
facilities in the source category. We extrapolated the risk results for 
the 135 modeled facilities up to the approximately 800 facilities in 
the source category and believe the resulting cancer and noncancer 
risks either represent or overstate risk from the 800 facilities in 
source category. However, we request comment on this approach, 
additional data on pollutant-specific emissions from facilities in the 
NEI, and identification of emissions from marine vessel loading 
facilities not included in the NEI.
    Marine terminals that are part of the petroleum refineries source 
category are not regulated by the Marine Vessel Loading Operations 
NESHAP. Therefore, marine terminals that are part of the petroleum 
refineries source category were not included in this risk assessment. 
The petroleum refineries marine terminals are being addressed in a 
separate RTR rulemaking action. (See the proposed RTR for Petroleum 
Refineries, 72 FR 50716, 09/04/2007.)
    Hexane, methanol, toluene, and mixed xylenes account for the 
majority of the HAP emissions from the 135 NEI facilities 
(approximately 184 TPY and 73 percent of the total HAP emissions by 
mass). These facilities also reported relatively small emissions of 42 
other HAP. These emissions are from the loading operations at the 
terminals. MACT allowable emission levels from this source category 
could be higher than actual emission levels due primarily to states 
requiring controls (typically 90 percent reduction) for some marine 
terminals that are not controlled by the Marine Vessel Loading 
Operations NESHAP. Based on typical state rule emission reduction 
requirements we estimate that the MACT allowable emissions from this 
source category would be 10 times the actual emissions for terminals 
not controlled by the Marine Vessel Loading Operations NESHAP and 
approximately

[[Page 60439]]

two times the actual emissions for marine terminals that are controlled 
by the Marine Vessel Loading Operations NESHAP.
3. Mineral Wool Production
    The National Emission Standards for Mineral Wool Production were 
promulgated on June 1, 1999 (64 FR 29489). The Mineral Wool Production 
NESHAP applies to major sources of HAP.
    Mineral wool is a fibrous, glassy substance made from natural rock 
(such as basalt), blast furnace slag, or other similar materials. In 
the mineral wool manufacturing process, rock and/or blast furnace slag 
and other raw materials (e.g., gravel) are melted in a furnace (cupola) 
using coke as a fuel. The molten material is then formed into fiber. 
Mineral wool is manufactured as either a ``bonded'' product that 
incorporates a binder to increase structural rigidity or a less rigid 
``nonbonded'' product. Products made from mineral wool are used for 
insulation, sound control and attenuation, and fire protection. The 
industry is declining significantly due to economic and competitive 
reasons (e.g., availability of alternative products such as cellulose 
insulation).
    Emission sources at mineral wool production facilities include the 
cupola furnace where the mineral charge is melted; a blow chamber, in 
which air or a binder is drawn over the fibers, forming them into a 
screen; a curing oven that bonds the fibers (for bonded products); and 
a cooling chamber. The majority of the emissions originate from the 
cupolas and curing ovens. The NESHAP requires control of particulate 
matter emissions from the cupolas and formaldehyde emissions from the 
curing ovens. Typical control devices used to reduce HAP emissions from 
the cupola include baghouses/fabric filters, and emissions from the 
curing ovens are generally controlled with thermal incinerators.
    We identified eight facilities currently subject to the Mineral 
Wool Production NESHAP. Some of these facilities also have other HAP-
emitting sources that are regulated under separate NESHAP, which have 
been or will be addressed in separate RTR rulemaking actions.
    Carbonyl sulfide accounts for the majority of the HAP emissions 
from these facilities (approximately 416 TPY and 87 percent of the 
total HAP emissions by mass). These facilities also reported relatively 
small emissions of 16 other HAP. The majority of HAP emissions are from 
the cupolas (approximately 80 percent of the total HAP by mass). The 
majority of HAP emissions (primarily formaldehyde) that were 
significant in evaluating risk are from the cooling chambers. We 
estimate that MACT allowable emissions from this source category could 
be as high as two times the actual emissions.
4. Pharmaceuticals Production
    The National Emission Standards for Pharmaceuticals Production were 
promulgated on September 21, 1998 (63 FR 50280). The Pharmaceuticals 
Production NESHAP applies to major sources of HAP.
    The pharmaceutical manufacturing process consists of chemical 
production operations that produce drugs and medication. These 
operations include chemical synthesis (deriving a drug's active 
ingredient) and chemical formulation (producing a drug in its final 
form).
    Emission sources at pharmaceutical production facilities include 
breathing and withdrawal losses from chemical storage tanks, venting of 
process vessels, leaks from piping and equipment used to transfer HAP 
compounds (equipment leaks), and volatilization of HAP from wastewater 
streams.
    Typical control devices used to reduce HAP emissions from process 
vents include flares, incinerators, scrubbers, carbon adsorbers, and 
condensers. Emissions from storage vessels are controlled by floating 
roofs or by routing them to a control device. Emissions from wastewater 
are controlled by a variety of methods, including equipment 
modifications (e.g., fixed roofs on storage vessels and oil water 
separators; covers on surface impoundments containers, and drain 
systems), treatment to remove the HAP (steam stripping, biological 
treatment), control devices, and work practices. Emissions from 
equipment leaks are typically reduced by leak detection and repair work 
practice programs, and in some cases, by equipment modifications.
    We identified 27 facilities currently subject to the 
Pharmaceuticals Production NESHAP. Some of these facilities are located 
at plant sites that also have other HAP-emitting sources regulated 
under separate NESHAP, which have been or will be addressed in separate 
rulemaking actions.
    Methylene chloride, methanol, acetonitrile, and toluene account for 
the majority of the HAP emissions from these facilities (approximately 
891 TPY and 90 percent of the total HAP emissions by mass). These 
facilities also reported relatively small emissions of 65 other HAP. 
The majority of HAP emissions are from the process vents (approximately 
70 percent of the total HAP by mass emitted from process vents, with 20 
percent and 10 percent of the total HAP by mass emitted from equipment 
leaks and wastewater operations, respectively). We estimate that MACT 
allowable emissions from this source category could be up to 25 percent 
greater than the actual emissions, primarily from process vents, as it 
is possible that the control devices used at some facilities achieve 
greater emission reductions from these emission sources than what is 
required by the NESHAP.
5. Printing and Publishing Industry
    The National Emission Standards for the Printing and Publishing 
Industry were promulgated on May 30, 1996 (61 FR 27132). The Printing 
and Publishing NESHAP applies to major sources of HAP.
    Printing and publishing facilities are those facilities that use 
rotogravure, flexography, and other methods, such as lithography, 
letterpress, and screen printing, to print on a variety of substrates, 
including paper, plastic film, metal foil, and vinyl. The Printing and 
Publishing NESHAP focuses on two subcategories: (1) Publication 
rotogravure printing and (2) product and packaging rotogravure and 
wide-web flexographic printing. Emissions at printing and publishing 
facilities result from the evaporation of solvents in the inks and from 
cleaning solvents. The emission points include printing presses and 
associated dryers and ink and solvent storage. Control techniques 
include recovery devices, combustion devices, and the use of non-HAP/
low-HAP inks and cleaning solvents.
    We estimate that approximately 200 facilities are subject to the 
Printing and Publishing NESHAP based on the information we gathered in 
support of the rule development in 1996. As data were available for 179 
major source facilities in the 2002 NEI, our analyses are based on 
these 179 facilities. We believe the 179 facilities represent the 
source category because: (1) We have no reason to believe that 
emissions from the other facilities are different from the facilities 
we modeled; (2) the difference between the number of facilities counted 
in 1996 and 2002 might be accounted for by facility closures and by 
some facilities achieving area source status for HAP before the first 
compliance date of the Printing and Publishing NESHAP; and, (3) we 
believe in most cases data on 90 percent of the facilities in a source 
category will be representative of the source category as a whole. Some 
of these facilities are located at plant sites that also have other 
HAP-emitting sources regulated

[[Page 60440]]

under separate NESHAP, which have been or will be addressed in separate 
RTR rulemaking actions.
    Toluene accounts for the majority of the HAP emissions from these 
facilities (approximately 6,606 TPY or 88 percent of the total HAP 
emissions by mass). These facilities also reported relatively small 
emissions of 56 other HAP. These emissions are primarily from the 
evaporation of HAP present in the inks and other materials applied with 
rotogravure and flexographic processes. We estimate that MACT allowable 
emissions from this source category could be up to 5 times greater than 
the actual emissions, as it is possible that the capture systems and 
control devices used at some facilities achieve greater emission 
reductions than what is required by the NESHAP.

D. How did we estimate risk posed by the nine source categories?

    To support the proposed decisions presented in today's notice, EPA 
conducted a risk assessment that provided estimates of MIR, maximum 
individual cancer risk distribution within the exposed populations, 
cancer incidence, hazard indices for chronic exposures to HAP with non-
cancer health effects, hazard quotients (HQ) for acute exposures to HAP 
with non-cancer health effects, and estimates of the potential for 
adverse environmental effects. The risk assessment consisted of seven 
primary activities: (1) Establishing the nature and magnitude of 
emissions from the source categories, (2) identifying the emissions 
release characteristics (e.g., stack parameters), (3) conducting 
dispersion modeling to estimate the concentrations of HAP in ambient 
air, (4) estimating long-term and short-term inhalation exposures to 
individuals residing within 50 km of the modeled sources, (5) 
estimating individual and population-level inhalation risks using the 
exposure estimates and quantitative dose-response information, (6) 
estimating the potential for adverse human health multipathway risks 
and for adverse environmental effects, and (7) characterizing risk. In 
general, the risk assessment followed a tiered, iterative approach, 
beginning with a conservative (worst case) screening-level analysis 
and, where the screening analyses indicated the potential for non-
negligible risks, following that with more refined analyses. The 
following sections summarize these activities. For more information on 
the risk assessment inputs and models, see ``Residual Risk Assessment 
for Nine Source Categories,'' available in the docket.
    We engaged in a consultation with a panel from the Science Advisory 
Board (SAB) on the ``Risk and Technology Review (RTR) Assessment Plan'' 
in December of 2006. The results of this consultation were transmitted 
to us in June 2007 in a letter from the SAB which also contained a 
summary listing of the key messages from the panel. The letter is 
available from the docket and from http://yosemite.epa.gov/sab/
sabproduct.nsf/33152C83D29530F08525730D006C3ABF/$File/sab-07-009.pdf. 
In developing the risk assessments for the nine source categories 
covered by this proposal, we followed the RTR Assessment Plan, 
addressing the key messages from the panel, where appropriate and 
relevant to these assessments.
1. Emissions and Emissions Release Characteristic Data
    The basic approach taken to obtain the most accurate and reliable 
emissions and emissions release characteristic data was to compile 
preliminary data sets using readily available information for each 
source category and to share these data with the public via an Advanced 
Notice of Proposed Rulemaking (ANPRM). The data sets were then updated 
based on comments received on the ANPRM and, in some cases, with 
additional information gathered by EPA.
    For the five Polymers and Resins I source categories 
(Epichlorohydrin Elastomers Production, HypalonTM Production, Nitrile 
Butadiene Rubber Production, Polybutadiene Rubber Production, and 
Styrene Butadiene Rubber and Latex Production), we collected emissions 
data and emissions release characteristic data directly from industry. 
These data generally formed the data sets used in our analyses for 
these source categories.
    For the remaining four source categories (Marine Vessel Loading, 
Mineral Wool, Pharmaceuticals, and Printing and Publishing), we created 
the preliminary data sets using the data in the 2002 NEI Final 
Inventory, Version 1 (made publicly available on February 26, 2006) 
supplemented by data collected directly from industry when available. 
The NEI is a database that contains information about sources that emit 
criteria air pollutants and their precursors, and HAP. The database 
includes estimates of annual air pollutant emissions from point, 
nonpoint, and mobile sources in the 50 States, the District of 
Columbia, Puerto Rico, and the Virgin Islands. EPA collects this 
information and releases an updated version of the NEI database every 3 
years.
    On March 29, 2007, we published an ANPRM (72 FR 29287) specifically 
to request comments and updates to these preliminary data sets. We 
received comments on emissions data and emissions release 
characteristics data for facilities in these nine source categories. 
These comments were reviewed, considered, and the emissions information 
was adjusted where we concluded the comments supported such adjustment. 
After incorporation of changes to the data sets from this public data 
review process, the final data sets were created. These data sets were 
used to conduct the risk assessments and other analyses that form the 
bases for these proposed actions.
    In addition to gathering information regarding the actual emissions 
from the sources in the nine source categories, we also examined the 
underlying NESHAP to determine whether the emissions that a source was 
allowed to emit when in compliance with the NESHAP would significantly 
vary from the actual emissions data we had gathered. Where such ``MACT 
allowable'' emission levels could be higher than the actual emission 
levels, we extrapolated the risks associated with the MACT allowable 
emission levels from the risks associated with the actual emission 
levels.
    The data sets for these nine source categories and documentation of 
the emissions data sets used for each source category are available in 
the RTR Group 2A docket. The documentation of the emission data sets 
provides a description of the changes in the dataset for each source 
category since the ANPRM, describes the data changes requested in 
public comments, and documents the analysis of MACT allowable emissions 
for each source category.
2. Dispersion Modeling, Inhalation Exposures, and Individual and 
Population Inhalation Risks
    Both long-term and short-term inhalation exposure concentrations 
and health risk from each of the nine source categories addressed in 
this proposal were estimated using the Human Exposure Model (Community 
and Sector HEM-3 version 1.1.0). The HEM-3 performs three of the 
primary risk assessment activities listed above: (1) Conducting 
dispersion modeling to estimate the concentrations of HAP in ambient 
air, (2) estimating long-term and short-term inhalation exposures to 
individuals residing within 50 km of the modeled sources, and (3) 
estimating individual and population-level inhalation risks using the 
exposure

[[Page 60441]]

estimates and quantitative dose-response information.
    The dispersion model used by HEM-3 is AERMOD, which is one of EPA's 
preferred models for assessing pollutant concentrations from industrial 
facilities.\4\ To perform the dispersion modeling and to develop the 
preliminary risk estimates, HEM-3 draws on three data libraries. The 
first is a library of meteorological data, which is used for dispersion 
calculations. This library includes 1 year of hourly surface and upper 
air observations for 130 meteorological stations, selected to provide 
thorough coverage of the United States and Puerto Rico. A second 
library of United States Census Bureau census block internal point 
locations and populations provides the basis of human exposure 
calculations (Census, 2000). In addition, the census library includes 
the elevation and controlling hill height for each census block, which 
are also used in dispersion calculations. A third library of pollutant 
unit risk factors and other health benchmarks is used to estimate 
health risks. These risk factors and health benchmarks are the latest 
values recommended by EPA for HAP and other toxic air pollutants. These 
values are available at http://www.epa.gov/ttn/atw/toxsource/summary.html and are discussed in more detail later in this section.
---------------------------------------------------------------------------

    \4\ Environmental Protection Agency. Revision to the Guideline 
on Air Quality Models: Adoption o fa Preferred General Purpose (Flat 
and Complex Terrain) Dispersion Model and Other Revisions (70 FR 
68218). November 9, 2005.
---------------------------------------------------------------------------

    In developing the risk assessment for chronic exposures, we used 
the estimated annual average ambient air concentration of each HAP 
emitted by each source for which we have emissions data in the source 
category at each nearby census block \5\ centroid as a surrogate for 
the chronic inhalation exposure concentration for all the people who 
reside in that census block. We calculated the MIR for each facility as 
the risk associated with a lifetime (70-year) exposure to the maximum 
concentration at the centroid of an inhabited census block. Individual 
cancer risks were calculated as the lifetime exposure to the ambient 
concentration of each HAP multiplied by its Unit Risk Estimate (URE), 
which is an upper bound estimate of an individual's probability of 
contracting cancer over a lifetime of exposure to a concentration of 
one microgram of the pollutant per cubic meter of air. For residual 
risk assessments, we generally use URE values from EPA's Integrated 
Risk Information System (IRIS). For carcinogenic pollutants without EPA 
IRIS values, we look to other reputable sources of cancer dose-response 
values, often using California Environmental Protection Agency (CalEPA) 
URE values, where available. In cases where new, scientifically 
credible dose-response values have been developed in a manner 
consistent with EPA guidelines and have undergone a peer review process 
similar to that used by EPA, we may use such dose-response values in 
place of or in addition to other values. Total cancer risks were the 
sum of the risks of each carcinogenic HAP (including known, probable, 
and possible carcinogens) emitted by the modeled source. Air 
concentrations of HAP from sources other than the modeled source were 
not estimated. Total cancer incidence and the distribution of 
individual cancer risks across the population within 50 kilometers of 
any source were also estimated as part of these assessments by summing 
individual risks. We are using 50 kilometers to be consistent with both 
the analysis supporting the 1989 Benzene NESHAP (54 FR 38044) and the 
limitations of Gaussian dispersion modeling.
---------------------------------------------------------------------------

    \5\ A typical census block is comprised of approximately 40 
people or about 10 households.
---------------------------------------------------------------------------

    To assess risk of noncancer health effects from chronic exposures, 
we summed the HQ for each HAP that affects a common target organ system 
to obtain the HI for that target organ system (or target organ-specific 
HI, TOSHI). The HQ is the estimated exposure divided by the chronic 
reference level, which is either the U.S. EPA Reference Concentration 
(RfC), defined as ``an estimate (with uncertainty spanning perhaps an 
order of magnitude) of a continuous inhalation exposure to the human 
population (including sensitive subgroups) that is likely to be without 
an appreciable risk of deleterious effects during a lifetime,'' or in 
cases where an RfC is not available, we use the CalEPA Chronic 
Reference Exposure Level (REL), which is defined as ``the concentration 
level at or below which no adverse health effects are anticipated for a 
specified exposure duration,'' or the ATSDR Chronic Minimum Risk Level 
(MRL), which is defined as ``an estimate of daily human exposure to a 
substance that is likely to be without an appreciable risk of adverse 
effects (other than cancer) over a specified duration of exposure.'' In 
cases where new, scientifically credible dose-response values have been 
developed in a manner consistent with EPA guidelines and have undergone 
a peer review process similar to that used by EPA, we may use such 
dose-response values in place of or in addition to other values.
    Screening estimates of acute exposures and risks were also 
evaluated for each HAP at any location off-site of each facility (i.e., 
not just the census block centroids) assuming the combination of a peak 
(hourly) emission rate and hourly dispersion conditions for the 1991 
calendar year that would tend to maximize exposure. In each case, acute 
HQ values were calculated using best available short-term health 
threshold values. These acute threshold values include REL, Acute 
Exposure Guideline Levels (AEGL), and Emergency Response Planning 
Guidelines (ERPG) for 1-hour exposure durations. Also, for those 
pollutants where no other threshold values (REL, AGEL, or ERPG) were 
available, we used ATSDR MRL values for 24-hour and greater exposure 
durations.
    As described in the California Environmental Protection Agency's 
``Air Toxics Hot Spots Program Risk Assessment Guidelines, Part I, The 
Determination of Acute Reference Exposure Levels for Airborne 
Toxicants,'' an acute REL (http://www.oehha.ca.gov/air/pdf/acuterel.pdf) is defined as ``the concentration level at or below which 
no adverse health effects are anticipated for a specified exposure 
duration is termed the reference exposure level (REL). RELs are based 
on the most sensitive, relevant, adverse health effect reported in the 
medical and toxicological literature. RELs are designed to protect the 
most sensitive individuals in the population by the inclusion of 
margins of safety. Since margins of safety are incorporated to address 
data gaps and uncertainties, exceeding the REL does not automatically 
indicate an adverse health impact.''
    Acute Exposure Guideline Levels, or AEGLs, were derived in response 
to recommendations from the National Research Council. As described in 
``Standing Operating Procedures (SOP) of the National Advisory 
Committee on Acute Exposure Guideline Levels for Hazardous Substances'' 
(http://www.epa.gov/opptintr/aegl/pubs/sop.pdf), \6\ ``the NRC's 
previous name for acute exposure levels--community emergency exposure 
levels (CEELs)--was replaced by the term AEGLs to reflect the broad 
application of these values to planning, response, and prevention in 
the community, the workplace, transportation, the military, and the 
remediation of Superfund

[[Page 60442]]

sites.'' This document also states (page 2) that AEGLs ``represent 
threshold exposure limits for the general public and are applicable to 
emergency exposures ranging from 10 min to 8 h.'' The document lays out 
the purpose and objectives of AEGLs by stating (page 21) that ``the 
primary purpose of the AEGL program and the NAC/AEGL Committee is to 
develop guideline levels for once-in-a-lifetime, short-term exposures 
to airborne concentrations of acutely toxic, high-priority chemicals.'' 
In detailing the intended application of AEGL values, the document 
states (page 31) that ``It is anticipated that the AEGL values will be 
used for regulatory and nonregulatory purposes by U.S. Federal and 
State agencies, and possibly the international community in conjunction 
with chemical emergency response, planning, and prevention programs. 
More specifically, the AEGL values will be used for conducting various 
risk assessments to aid in the development of emergency preparedness 
and prevention plans, as well as real-time emergency response actions, 
for accidental chemical releases at fixed facilities and from transport 
carriers.''
---------------------------------------------------------------------------

    \6\ National Academies of Science, 2001. Standing Operating 
Procedures for Developing Acute Exposure Levels for Hazardous 
Chemicals, page 2.
---------------------------------------------------------------------------

    The AEGL-1 value is then specifically defined as ``the airborne 
concentration of a substance above which it is predicted that the 
general population, including susceptible individuals, could experience 
notable discomfort, irritation, or certain asymptomatic nonsensory 
effects. However, the effects are not disabling and are transient and 
reversible upon cessation of exposure.'' The document also notes (page 
3) that, ``Airborne concentrations below AEGL-1 represent exposure 
levels that can produce mild and progressively increasing but transient 
and nondisabling odor, taste, and sensory irritation or certain 
asymptomatic, nonsensory effects.'' Similarly, the document defines 
AEGL-2 values as ``the airborne concentration (expressed as ppm or mg/
m3) of a substance above which it is predicted that the general 
population, including susceptible individuals, could experience 
irreversible or other serious, long-lasting adverse health effects or 
an impaired ability to escape.''
    ERPG are derived for use in emergency response, as described in the 
American Industrial Hygiene Association's document entitled, 
``Emergency Response Planning Guidelines (ERPG) Procedures and 
Responsibilities'' (http://www.aiha.org/1documents/committees/ERP-SOPs2006.pdf), which states that, ``Emergency Response Planning 
Guidelines (ERPGs) were developed for emergency planning and are 
intended as health based guideline concentrations for single exposures 
to chemicals.'' \7\ The ERPG-1 value is defined as ``the maximum 
airborne concentration below which it is believed that nearly all 
individuals could be exposed for up to 1 hour without experiencing 
other than mild transient adverse health effects or without perceiving 
a clearly defined, objectionable odor.'' Similarly, the ERPG-2 is 
defined as ``the maximum airborne concentration below which it is 
believed that nearly all individuals could be exposed for up to one 
hour without experiencing or developing irreversible or other serious 
health effects or symptoms which could impair an individual's ability 
to take protective action,''.
---------------------------------------------------------------------------

    \7\ ERP Committee Procedures and Responsibilities, 1 November 
2006. American Industrial Hygiene Association.
---------------------------------------------------------------------------

    As can be seen from the definitions above, the AEGL and ERPG values 
include the similarly defined severity levels 1 and 2. For many 
chemicals, the available information does not allow development of a 
severity level 1 value AEGL or ERPG; in these instances, higher 
severity level AEGL-2 or ERPG-2 values are compared to our modeled 
exposure levels to screen for potential acute concerns.
    Acute REL values for a 1-hour exposure duration are typically lower 
than their corresponding AEGL-1 and ERPG-1 values. Even though their 
definitions are slightly different, AEGL-1 values are often the same as 
the corresponding ERPG-1 values, and AEGL-2 values are often equal to 
ERPG-2 values. Maximum HQ values from our acute screening risk 
assessments typically result when basing them on the acute REL for a 
particular pollutant. In cases where our maximum acute HQ value exceeds 
1, we also report the HQ value based on the next highest acute 
threshold (usually the AEGL-1 and/or the ERPG-1).
    In cases where no acute REL, AEGL or ERPG value is available for 
the pollutant being assessed, we have calculated HQ values based on the 
Agency for Toxic Substances and Disease Registry's Minimal Risk Levels 
(MRL) to determine whether we can clearly assert that there is no 
potential for acute impact of concern. The MRL (http://www.atsdr.cdc.gov/mrls/) is defined as ``an estimate of the daily human 
exposure to a hazardous substance that is likely to be without 
appreciable risk of adverse noncancer health effects over a specified 
duration of exposure.'' Since acute exposure is defined by ATSDR in the 
context of MRL as ``exposure that occurs for a short time (1 to 14 
days),'' and since we are most interested in trying to assess the 
potential impact of shorter-duration high-emission events, we only use 
these HQ based on MRL values in the context of a screening check, 
wherein we adjust our maximum 1-hour exposures to estimate potential 
maximum 24-hour exposures using a meteorological adjustment factor of 
0.4.\8\ Because these MRL values are based on longer exposure durations 
than our peak 1-hour exposure estimates, they are generally more 
stringent than 1-hour thresholds, and therefore provided a very 
conservative screen. Thus, HQ values based on MRL which do not exceed 1 
provide a strong indication that acute impacts are not of potential 
concern. HQ values based on the MRL which exceed 1, however, do not 
automatically indicate an adverse health impact and may require further 
analysis.
---------------------------------------------------------------------------

    \8\ See ``Screening Procedures for Estimating the Air Quality 
Impact of Stationary Sources'' (Revised); EPA-454/R-92-019; Chapter 
4; page 15.
---------------------------------------------------------------------------

    To develop screening estimates of acute exposures, we developed 
estimates of maximum hourly emission rates by multiplying the average 
annual hourly emission rates by a factor of 10. The factor of 10 is 
intended to cover routinely variable emissions and startup, shutdown, 
and malfunction emissions. We chose to use a factor of 10 based on: (1) 
Engineering judgment, and (2) an analysis of short-term emissions data 
that compared hourly and annual emissions data for volatile organic 
compounds (VOC) for all facilities in a heavily-industrialized 4-county 
area (Harris, Galveston, Chambers, and Brazoria Counties, TX) over an 
11-month time period in 2001.\9\ The analysis is provided in Appendix 4 
of the Draft Residual Risk Assessment for 9 Source Categories and is 
available in the docket for this rule. In this study, most peak 
emission events were less than twice the annual average hourly emission 
rate and the highest peak emission event was 8.5 times the annual 
average hourly emission rate. We request comment on the interpretation 
of these data and the appropriateness of using a factor of 10 times the 
average annual hourly emission rate in these acute exposure screening 
assessments.
---------------------------------------------------------------------------

    \9\ See http://www.tceq.state.tx.us/compliance/field_ops/eer/index.html or docket to access the source of these data.
---------------------------------------------------------------------------

    In cases where all acute HQ values from the screening step were 
less than or equal to 1, acute impacts were deemed negligible and no 
further analysis was performed. In the cases where an acute HQ from the 
screening step was greater than 1, additional site-specific data were 
considered to develop a more refined estimate of the

[[Page 60443]]

potential for acute impacts of concern. The data refinements considered 
included using a better representation of the peak-to-mean hourly 
emissions ratio (instead of using the default factor of 10) and using 
the site-specific facility layout to distinguish facility property from 
an area where the public could be exposed. Ideally we would prefer to 
have continuous measurements over time to see how the emissions vary by 
each hour over an entire year. Having a frequency distribution of 
hourly emission rates over a year would allow us to perform a 
probabilistic analysis to estimate potential threshold exceedances and 
their frequency of occurrence. We recognize that having this level of 
data is rare, hence our use of the factor of 10 multiplier approach. 
Such an evaluation could include a more complete statistical treatment 
of the key parameters and elements adopted in this screening analysis.
    In the final step of the acute impacts screening, HQ values 
exceeding 1 based on REL, AEGL, ERPG, or MRL values are interpreted on 
a case-by-case basis, considering the implications of the appropriate 
definitions and the related supporting documentation for that specific 
value, as well as the context of the HQ based on the next highest acute 
threshold value, where one is available.
3. Multipathway Human Health Risks and Environmental Effects Assessment
    The potential for significant human health risks due to exposures 
via routes other than inhalation (i.e., multipathway exposures) and the 
potential for adverse environmental impacts were evaluated in a two-
step screening process. In the first step, each source category was 
screened by determining whether any sources emitted any of the 14 HAP 
known to be persistent and bioaccumulative in the environment (also 
known as PB-HAP)\10\, as identified in EPA's Air Toxics Risk Assessment 
Library (available at http://www.epa.gov/ttn/fera/risk_atra_vol1.html). As a result of this screening, we determined that four of 
the RTR Group 2A source categories--Marine Vessel Loading Operations, 
Mineral Wool Production, Pharmaceuticals Production, and the Printing 
and Publishing Industry--were responsible for air emissions of four PB-
HAP--cadmium compounds, mercury compounds, lead compounds, and 
polycyclic organic matter (POM).
---------------------------------------------------------------------------

    \10\ Persistent and bioaccumulative (PB) HAP are HAP that have 
the ability to persist in the environment for long periods of time 
and may also have the ability to build up in the food chain to 
levels that are harmful to human health and the environment.
---------------------------------------------------------------------------

    In the second step of the screening process, we determined if the 
facility-specific emission rates of each of the specific PB-HAP were 
large enough to create the potential for significant non-inhalation 
risks. To facilitate this step, we developed emission rate thresholds 
for each PB-HAP using a hypothetical screening exposure scenario 
developed for use in conjunction with the TRIM.FaTE model. The 
hypothetical screening scenario was subjected to a sensitivity analysis 
to ensure that its key design parameters were established such that 
environmental media concentrations were not underestimated (i.e., to 
minimize the occurrence of false positives, or results that suggest 
that risks might be acceptable when, in fact, actual risks are high), 
and to also minimize the occurrence of false positives for human health 
endpoints. We call this application of the TRIM.FaTE model TRIM-Screen. 
The facility-specific emission rates of each PB-HAP in each source 
category were compared to the emission threshold values for each of the 
four PB-HAP identified in the source category datasets. None of the 
emission rates for the facilities source categories addressed in this 
action exceeded the emission threshold values; therefore, none of the 
facilities show the potential for causing any significant multipathway 
exposures and risks. Had this not been the case, the source categories 
would have been further evaluated for potential non-inhalation risks 
and adverse environmental impacts through site-specific refined 
assessments using EPA's TRIM.FaTE model. For further information on the 
multipathway screening see the ``Residual Risk Assessment for 9 Source 
Categories'' document (see Docket EPA-HQ-OAR-2008-0008).
4. Risk Characterization
    The final product of the risk assessment is the risk 
characterization, in which the information from the previous steps is 
integrated and an overall conclusion about risk is derived. Estimates 
of health risk are considered in the context of uncertainties and 
limitations in the data and methodology. In general, we have attempted 
to reduce both uncertainty and bias to the greatest degree possible in 
these assessments. A brief discussion of the major uncertainties 
associated with the derivation of risk estimates is provided below. The 
first section discusses the consideration of ``MACT allowable'' 
emissions in risk characterization, followed by a discussion of 
uncertainties in risk assessments. Following these sections, we have 
provided summaries of risk metrics for each source category (including 
MIR and noncancer hazards, as well as cancer incidence estimates).
    We note here that several of the carcinogens emitted by these 
source categories (i.e., benzo[a]pyrene, dibenz[a,h]anthracene, and 
vinyl chloride) have a mutagenic mode of action\11\, EPA's 
``Supplemental Guidance for Assessing Susceptibility from Early-Life 
Exposure to Carcinogens'' \12\ was applied to the risk estimates for 
these four compounds. This guidance has the effect of adjusting the URE 
by factors of 10 (for children aged 0-1), 3 (for children aged 2-15), 
or 1.6 (for 70 years of exposure beginning at birth), as needed in risk 
assessments. In this case, this has the effect of increasing the 
estimated lifetime risks for these pollutants by a factor of 1.6. In 
addition, although only a small fraction of the total POM emissions 
were reported as individual compounds, EPA expresses carcinogenic 
potency for compounds in this group in terms of benzo[a]pyrene 
equivalence, based on evidence that carcinogenic POM have the same 
mutagenic mechanism of action as does benzo[a]pyrene. For this reason 
EPA implementation policy \13\ recommends applying the Supplemental 
Guidance to all carcinogenic PAHs for which risk estimates are based on 
relative potency. Accordingly, we have applied the Supplemental 
Guidance to all unspeciated POM mixtures.
---------------------------------------------------------------------------

    \11\ U.S. EPA, 2006. Performing risk assessments that include 
carcinogens described in the Supplemental Guidance as having a 
mutagenic mode of action. Science Policy Council Cancer Guidelines 
Implementation Workgroup Communication II: Memo from W.H. Farland 
dated 14 June 2006. http://epa.gov/osa/spc/pdfs/CGIWGCommunication_II.pdf.
    \12\ U.S. EPA, 2005. Supplemental Guidance for Assessing Early-
Life Exposure to Carcinogens. EPA/630/R-03/003F. http://www.epa.gov/ttn/atw/childrens_supplement_final.pdf.
    \13\ U.S. EPA, 2005. Science Policy Council Cancer Guidelines 
Implementation Workgroup Communication I: Memo from W.H. Farland 
dated 4 October 2005 to Science Policy Council. http://www.epa.gov/osa/spc/pdfs/canguid1.pdf.
---------------------------------------------------------------------------

    Finally, we screened chronic ambient concentration levels of all 
individual HAP against their chronic noncancer human health thresholds 
in an effort to gauge the potential for adverse environmental impacts, 
under the assumption that chronic human toxicity values are generally 
protective of direct inhalation impacts on animals and direct contact 
impacts on plants. We believe that this assumption is reasonable in 
most cases, but acknowledge that it is an uncertainty. Although not 
verified for many HAP

[[Page 60444]]

because of lacking environmental testing data, this assumption has been 
shown to be valid for some organic compounds \14\ where such test data 
are available.
a. Consideration of Actual and MACT Allowable Emissions
---------------------------------------------------------------------------

    \14\ ``Evaluation of Wildlife Inhalation Exposure Pathway from 
Wood Products Plant Emissions.'' Memorandum to Tim Hunt/AF&PA from 
David F. Mitchell and Julie A.F. Kabel, February 25, 2002. This 
memorandum is in the docket.
---------------------------------------------------------------------------

    We discussed the use of both MACT allowable and actual emissions in 
the final Coke Oven Batteries residual risk rule (70 FR 19998-19999, 
April 15, 2005) and in the proposed and final Hazardous Organic NESHAP 
(HON) residual risk rules (71 FR 34428, June 14, 2006, and 71 FR 76609, 
December 21, 2006, respectively). In those previous actions, we noted 
that assessing the MACT allowable levels of emissions (i.e., the 
highest emission levels that could be emitted while maintaining the 
same activity level and still complying with the NESHAP requirements) 
is inherently reasonable since they reflect the maximum level sources 
could emit and still comply with national emission standards. But we 
also explained that it is reasonable to consider actual emissions, 
where such data are available, in both steps of the risk analysis, in 
accordance with the Benzene NESHAP. (54 FR 38044, September 14, 1989). 
It is reasonable to consider actual emissions because sources typically 
seek to perform better then required by emission standards to provide 
an operational cushion to accommodate the variability in manufacturing 
processes and control device performance. Failure to consider actual 
emissions data in developing risk estimates would unrealistically 
inflate estimated risk levels.
    We performed our risk assessments based on estimates of actual 
emission levels as developed through the process described earlier in 
the preamble. For the nine source categories addressed in this action, 
we do not have detailed information regarding MACT allowable emission 
levels. However, we estimated the potential differences in MACT 
allowable and actual emission levels for each source category and where 
MACT allowable emission levels were greater than actual emission 
levels, we scaled the risk results by the ratio of MACT allowable to 
actual emission levels. In many cases, the requirements of the 
regulation result in actual emission levels being a reasonable 
approximation of or the same as MACT allowable emission levels. In 
section I.E. of this preamble, the potential risk based on 
consideration of MACT allowable emission levels is discussed for each 
source.
b. Uncertainties in Risk Assessments
    Uncertainty and the potential for bias are inherent in all risk 
assessments, including those performed for the nine source categories 
affected by this proposal. We reduced some of these uncertainties by 
soliciting input from industry and the public to develop the best 
emissions data sets possible. Although uncertainty exists, we believe 
the risk assessments performed for the nine source categories most 
likely overestimate the potential for risks due to the health-
protective assessment approach. A brief discussion of the uncertainties 
in the emissions data set, dispersion modeling, inhalation exposure 
estimates, and dose-response relationships is presented in this section 
of the preamble. A more thorough discussion of these uncertainties is 
included in both the ``Residual Risk Assessment for 9 Source 
Categories'' (April 2008) and the ``Risk and Technology Review (RTR) 
Assessment Plan'' (November 2006), both of which are available in the 
docket.
    Uncertainties in the Emissions Data Sets. Although the development 
of the RTR data sets involved quality assurance/quality control 
processes, the accuracy of emissions values will vary depending on the 
source of the data present, incomplete or missing data, errors in 
estimating emissions values, and other factors. The emission values 
considered in this analysis are annual totals that do not reflect 
short-term fluctuations during the course of a year or variations from 
year to year. These annual emissions estimates generally do not include 
operations such as startup/shutdown and malfunctions; \15\ however, 
such emissions are not known to contribute significantly to total 
annual emissions. In contrast, the estimates of peak hourly emission 
rates for the acute effects screening assessment were based on the 
generally health-protective default assumption of 10 times the annual 
average hourly rate which is intended to account for emission 
fluctuations due to normal facility operations as well as emissions 
from startup, shutdown and malfunctions events. More refined estimates 
were used for source categories where the screening estimates did not 
``screen out'' all sources and more specific information was available.
---------------------------------------------------------------------------

    \15\ The mass balance used to determine emissions from the 
publication rotogravure subcategory of the Printing and Publishing 
source category includes emissions from startup, shutdown, and 
malfunction events.
---------------------------------------------------------------------------

    Facilities in seven of the source categories (Epichlorohydrin 
Elastomers Production, Hypalon\TM\ Production, Marine Tank Vessel 
Loading, Pharmaceuticals Production, Polybutadiene Rubber Production, 
Printing and Publishing, and Styrene Butadiene Rubber and Latex 
Production) emit chlorinated compounds and use incineration devices, 
creating the possibility for the formation of polychlorinated dioxins. 
However, we have no test reports or measurements, conducted by 
manufacturers or anyone else, indicating the presence of dioxins in the 
emissions from any of these source categories, and EPA's dioxin 
inventory does not specifically link dioxins emissions to any of these 
source categories. Furthermore, in our judgment, it is improbable that 
dioxins are emitted in measurable amounts from these seven source 
categories given the low quantity of particulate matter present. 
Therefore, we did not consider dioxins in our assessment of these 
source categories.
    Overall we believe that the emissions data considered in this 
assessment are accurate representations of the actual emissions for 
facilities in the nine source categories for the stated purpose. 
Nevertheless, we request comment on our emissions data set in general 
(including information on individual sources), and specifically on our 
approach for estimating: short-term emissions used in assessing acute 
risk; emissions and associated risk from start-ups, shutdowns, and 
malfunctions (SSM); and on the potential for dioxins emissions from the 
source categories affected by this proposal. We also request comment on 
evaluating potential emissions mitigation (emission limits, work 
practice standards, and best management practices) for SSM events and 
the associated reduction in emissions and risks and the associated 
costs.
    Uncertainties in Dispersion Modeling. While the analysis employed 
EPA's suggested regulatory dispersion model, AERMOD, there is 
uncertainty in ambient concentration estimates associated with EPA's 
choice and application of the model. Where possible, model options 
(e.g., rural/urban, plume depletion, chemistry) were selected to 
provide an overestimate of ambient air concentrations. However, because 
of practicality and data limitation reasons, some factors (e.g., 
meteorology, building downwash) have the potential in some situations 
to overestimate or

[[Page 60445]]

underestimate ambient impacts. For example, meteorological data were 
taken from a single year (1991), and facility locations can be a 
significant distance from the site where these data were taken. Despite 
these uncertainties, we believe that at off-site locations and census 
block centroids, the approach considered in the dispersion modeling 
analysis should generally yield overestimates of ambient 
concentrations.
    Uncertainties in Inhalation Exposure. The effects of human mobility 
on exposures were not included in the assessment. Specifically, short-
term mobility and long-term mobility \16\ between census blocks in the 
modeling domain were not considered. As a result, this simplification 
will likely bias the assessment toward overestimating the highest 
exposures. In addition, the assessment predicted the chronic exposures 
at the centroid of each populated census block as surrogates for the 
exposure concentrations for all people living in that block. (On 
average census blocks are populated by approximately 40 people.) Using 
the census block centroid to predict chronic exposures tends to 
overpredict exposures for people in the census block who live further 
from the facility and underpredict exposures for people in the census 
block who live closer to the facility. Thus, using the census block 
centroid to predict chronic exposures may lead to a potential 
understatement or overstatement of the true maximum impact, but is an 
unbiased estimate of average risk and incidence.
---------------------------------------------------------------------------

    \16\ Short-term mobility is movement from one microenvironment 
to another over the course of hours or days. Long-term mobility is 
movement from one residence to another over the course of a 
lifetime.
---------------------------------------------------------------------------

    The assessments evaluate the cancer inhalation risks associated 
with pollutant exposures over a 70-year period, the assumed lifetime of 
individuals. In reality, both the length of time that modeled emissions 
sources at facilities actually operate (i.e., more or less than 70 
years), and the domestic growth or decline of the modeled industry 
(i.e., the increase or decrease in the number or size of United States 
facilities), will influence the risks posed by a given source category. 
Depending on the characteristics of the industry, these factors will 
likely result in an overestimate (or possibly an underestimate in the 
extreme case where a facility maintains or increases its emission 
levels beyond 70 years and residents live beyond 70 years at the same 
location) both in individual risk levels and in the total estimated 
number of cancer cases. Annual cancer incidence estimates from 
exposures to emissions from these sources would not be affected by 
uncertainty in the length of time emissions sources operate.
    The exposure estimates used in these analyses assume chronic 
exposures to ambient levels of pollutants. Because most people spend 
the majority of their time indoors, actual exposures may not be the 
same, depending on characteristics of the pollutants modeled. For many 
HAP, indoor levels are roughly equivalent to ambient levels, but for 
very reactive pollutants or larger particles, these levels are 
typically lower. This factor has the potential to result in an 
overstatement of 25 to 30 percent of exposures.\17\
---------------------------------------------------------------------------

    \17\ National-Scale Air Toxics Assessment for 1996. (EPA 453/R-
01-003; January 2001; page 85.)
---------------------------------------------------------------------------

    In addition to the uncertainties highlighted above, there are 
several factors specific to the acute exposure assessment that need to 
be highlighted. The accuracy of an acute inhalation exposure assessment 
depends on the simultaneous occurrence of independent factors that may 
vary greatly, such as hourly emissions rates, meteorology, and human 
activity patterns. In this assessment, we assume that individuals 
remain for 1 hour at the point of maximum ambient concentration as 
determined by the co-occurrence of peak emissions and worst-case 
meteorological conditions. These assumptions would tend to overestimate 
actual exposures since it is unlikely that a person would be located at 
the point of maximum exposure during the time of worst-case impact.
    Uncertainties in Dose-Response Relationships. There are 
uncertainties inherent in the development of the reference values used 
in our risk assessments for cancer effects from chronic exposures and 
noncancer effects from both chronic and acute exposures. Some 
uncertainties may be considered quantitatively, and others generally 
are expressed in qualitative terms. We note as a preface to this 
discussion a point which pertains to this whole discussion on dose-
response uncertainty and which is brought out in EPA's 2005 Cancer 
Guidelines; namely, that ``the primary goal of EPA actions is 
protection of human health; accordingly, as an Agency policy, risk 
assessment procedures, including default options that are used in the 
absence of scientific data to the contrary, should be health 
protective.'' (EPA 2005 Cancer Guidelines, pages 1-7) This is the 
approach followed here as summarized in the next several paragraphs. A 
complete detailed discussion of uncertainties and variabilities in dose 
response relationships is given in the risk assessment document.
    Cancer URE values used in our risk assessments are those that have 
been developed to generally provide an upper bound estimate of risk. 
That is, they represent a ``plausible upper limit to the true value of 
a quantity'' (although this is usually not a true statistical 
confidence limit).\18\ In some circumstances, the true risk could be as 
low as zero; however, in other circumstances the risk could also be 
greater.\19\ When developing an upper bound estimate of risk and to 
provide risk values that do not underestimate risk, health-protective 
default approaches are generally used. EPA typically uses the upper 
bound estimates rather than lower bound or central tendency estimates 
in our risk assessments, an approach that can have limitations for 
other uses (e.g., priority-setting or expected benefits analysis).
---------------------------------------------------------------------------

    \18\ IRIS glossary (http://www.epa.gov/NCEA/iris/help_gloss.htm).
    \19\ An exception to this is the URE for benzene, which is 
considered to cover a range of values, each end of which is 
considered to be equally plausible, and which is based on maximum 
likelihood estimates.
---------------------------------------------------------------------------

    Chronic noncancer reference (RfC and RfD) values represent chronic 
exposure levels that are intended to be health-protective levels. 
Specifically, these values provide an estimate (with uncertainty 
spanning perhaps an order of magnitude) of daily oral exposure (RfD) or 
of a continuous inhalation exposure (RfC) to the human population 
(including sensitive subgroups) that is likely to be without an 
appreciable risk of deleterious effects during a lifetime. To derive 
values that are intended to be ``without appreciable risk,'' the 
methodology relies upon an uncertainty factor (UF) approach (U.S. EPA, 
1993, 1994) which includes consideration of both uncertainty and 
variability. When there are gaps in the available information, UF are 
applied to derive reference values that are intended to be protective 
against appreciable risk of deleterious effects. Uncertainty factors 
are commonly default values,\20\ e.g.,

[[Page 60446]]

factors of 10 or 3, used in the absence of compound-specific data; 
where data are available, uncertainty factors may also be developed 
using compound-specific information. When data are limited, more 
assumptions are needed and more uncertainty factors are used. Thus 
there may be a greater tendency to overestimate risk-in the sense that 
further study might support development of reference values that are 
higher (i.e., less potent) because fewer default assumptions are 
needed. However, for some pollutants it is possible that risks may be 
underestimated.
---------------------------------------------------------------------------

    \20\ According to the NRC report Science and Judgment in Risk 
Assessment (NRC, 1994) ``[Default] options are generic approaches, 
based on general scientific knowledge and policy judgment, that are 
applied to various elements of the risk-assessment process when the 
correct scientific model is unknown or uncertain.'' The 1983 NRC 
report Risk Assessment in the Federal Government: Managing the 
Process defined default option as ``the option chosen on the basis 
of risk assessment policy that appears to be the best choice in the 
absence of data to the contrary'' (NRC, 1983a, p. 63). Therefore, 
default options are not rules that bind the agency; rather, the 
agency may depart from them in evaluating the risks posed by a 
specific substance when it believes this to be appropriate. In 
keeping with EPA's goal of protecting public health and the 
environment, default assumptions are used to ensure that risk to 
chemicals is not underestimated (although defaults are not intended 
to overtly overestimate risk). See EPA 2004 An examination of EPA 
Risk Assessment Principles and Practices, EPA/100/B-04/001 available 
at: http://www.epa.gov/osa/pdfs/ratf-final.pdf.
---------------------------------------------------------------------------

    While collectively termed ``UF'', these factors account for a 
number of different quantitative considerations when utilizing observed 
animal (usually rodent) or human toxicity data in the development of 
the reference concentration. The UF are intended to account for: (1) 
Variation in susceptibility among the members of the human population 
(i.e., inter-individual variability); (2) uncertainty in extrapolating 
from experimental animal data to humans (i.e., interspecies 
differences); (3) uncertainty in extrapolating from data obtained in a 
study with less-than-lifetime exposure (i.e., extrapolating from 
subchronic to chronic exposure); (4) uncertainty in extrapolating the 
observed data to obtain an estimate of the exposure associated with no 
adverse effects; and (5) uncertainty when the database is incomplete or 
there are problems with the applicability of available studies.
    Many of the UF used to account for variability and uncertainty in 
the development of acute reference values are quite similar to those 
developed for chronic durations, but more often using individual UF 
values that may be less than 10. UF are applied based on chemical-
specific or health effect-specific information (e.g., simple irritation 
effects do not vary appreciably between human individuals, hence a 
value of 3 is typically used), or based on the purpose for the 
reference value (see the following paragraph). The UF applied in acute 
reference value derivation include: (1) Heterogeneity among humans; (2) 
uncertainty in extrapolating from animals to humans; (3) uncertainty in 
LOAEL to NOAEL adjustments; and (4) uncertainty in accounting for an 
incomplete database on toxic effects of potential concern. Additional 
adjustments are often applied to account for uncertainty in 
extrapolation from observations at one exposure duration (e.g., 4 
hours) to derive an acute reference value at another exposure duration 
(e.g., 1 hour).
    Not all acute reference values are developed for the same purpose 
and care must be taken when interpreting the results of an acute 
assessment of human health effects relative to the reference value or 
values being exceeded. Where relevant to the estimated exposures, the 
lack of threshold values at different levels of severity should be 
factored into the risk characterization as potential uncertainties. 
Further, when we compare our peak 1-hour exposures against MRL values 
(which are derived for 1- to 14-day exposure durations), we note that 
peak emission events are unlikely to last more than an hour. As such, 
these comparisons are a very conservative screen which is only useful 
in ruling out potential exposures of concern, limiting our ability to 
interpret situations where MRL values are exceeded.
    Although every effort is made to identify peer-reviewed reference 
values for cancer and noncancer effects for all pollutants emitted by 
the sources included in this assessment, some pollutants have no peer-
reviewed reference values for cancer or chronic non-cancer or acute 
effects. Since exposures to these pollutants cannot be included in a 
quantitative risk estimate, an understatement of risk for these 
pollutants at environmental exposure levels is possible.
    Additionally, chronic reference values for 26 of the compounds 
included in this assessment are currently under EPA IRIS review and 
revised assessments may determine that these pollutants are more or 
less potent than the current value. We will re-evaluate residual risks 
if, as a result of these reviews, a dose-response metric changes enough 
to indicate that the risk assessment supporting today's notice may 
significantly understate human health risk.
    Uncertainties in the Multipathway and Environmental Effects 
Assessment. We generally believe that when exposure levels are not 
anticipated to adversely affect human health, they also are not 
anticipated to adversely affect the environment. While there are 
special considerations for certain HAP, we generally rely on the levels 
of PB-HAP emissions to determine whether a full assessment of the 
multipathway and environmental effects is necessary. Because emissions 
of these chemicals may not be well characterized due to lack of testing 
requirements specific to these chemicals (e.g., these compounds may be 
aggregated into testing requirements for particulate matter), risks may 
be understated.

E. What are the results of the risk assessment?

    The human health risks estimated for the nine source categories are 
summarized in this section of the preamble. Details of the assessment 
are located in the docket (Docket EPA-HQ-OAR-2008-0008), especially see 
``Residual Risk Assessment for 9 Source Categories.'' We believe that 
our assessment covers all potential health risks associated with HAP 
emissions from the nine source categories affected by this proposal.
    For each of the nine source categories, the cancer MIR from one or 
more exposure routes was greater than 1-in-1 million and/or the maximum 
HQ for acute exposure was greater than 1. Table 4 provides an overall 
summary of the inhalation risk assessment results, and the sections 
below provide more detailed discussions about the risk assessment 
results for each of the nine source categories.

                  Table 4--Summary of Estimated Inhalation Risks for the Nine Source Categories
----------------------------------------------------------------------------------------------------------------
                                               Maximum
                                              individual   Population                 Maximum
                                Number of    cancer risk   at risk >=     Annual      chronic      Maximum off-
       Source category        facilities\1\     (in a       1-in-a-       cancer     noncancer      site acute
                                               million)     million     incidence    TOSHI \3\   noncancer HQ\4\
                                                 \2\       (1,000's)
----------------------------------------------------------------------------------------------------------------
Epichlorohydrin Elastomers               1            30            4       0.0004          0.2  HQREL = 0.1
 Production.                                                                                      epichlorohydri
                                                                                                  n
HypalonTM Production........             1             1          0.4       0.0004          0.1  HQREL = 0.7
                                                                                                  chlorine

[[Page 60447]]

 
Nitrile Butadiene Rubber                 4            60           47        0.004          0.9  HQREL = 0.3
 Production.                                                                                      styrene
Polybutadiene Rubber                     5            10           16        0.002          0.2  HQREL = 0.3
 Production.                                                                                      toluene
Styrene Butadiene Rubber and             9             7           26        0.004          0.1  HQREL = 0.3
 Latex Production.                                                                                styrene
Marine Vessel Loading                 <800             1          2.4         0.01        0.006  HQAEGL	2 = 0.9
 Operations.                                                                                      chloroform
Mineral Wool Production.....             8            30          110        0.008          0.4  HQREL = 8
                                                                                                 HQAEGL	1 = 0.7
                                                                                                  formaldehyde
                                                                                                 HQREL = 4
                                                                                                  arsenic
Pharmaceuticals Production..            27            10          4.9        0.001          0.2  HQREL = 2
                                                                                                  chloroform
                                                                                                 HQAEGL	1 = 0.5
                                                                                                  acetonitrile
Printing and Publishing                179          0.05            0     0.000009         0.08  HQREL = 10
 Industry.                                                                                       HQAEGL	1 = 0.5
                                                                                                  toluene
----------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum target organ specific hazard index (TOSHI). Target organ system represented by the TOSHI varies
  across source categories. Maximum TOSHI is respiratory for the printing and publishing industry, mineral wood
  production, epichlorohydrin elastomers production, and Hypalon[supreg] production. Maximum TOSHI for marine
  vessel loading operations is based on immunological effects. Maximum TOSHI for nitrile butadiene rubber
  production, polybutadiene rubber production, and styrene butadiene rubber and latex production is based on
  reproductive effects. Maximum TOSHI for pharmaceutical production is based on neurological effects.
\4\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to
  develop an array of hazard quotient (HQ) values. HQ values shown use the lowest available acute threshold
  value, which in most cases is the REL. When HQ values exceed 1, we also show HQ values using the next lowest
  available acute threshold. For the Mineral Wool Production Category, there were potential exceedances of the
  REL for arsenic (maximum HQ = 4, as noted in the table), but there is no corresponding AEGL-1 value to
  facilitate further interpretation of these exceedances. See Section 2 of this preamble for explanation of
  acute threshold values.

    As shown in Table 4, we estimate, based on actual emissions, that 
the MIR remaining from HAP emissions from these nine source categories 
affected by this proposal range from 0.05-in-1 million to 60-in-1 
million. Cancer incidence ranged from 0.000009 excess cancer cases per 
year (or nine cases every 1,000,000 years) to 0.01 excess cancer cases 
per year (or one excess cancer case every 100 years). No chronic 
noncancer inhalation human health thresholds were exceeded at off-site 
receptors for any of the nine source categories. The maximum acute HQ 
using the REL ranged from 0.1 to 10 and were all less than 1 (ranging 
from 0.3 to 0.9) for the AEGL or ERPG where available. We extrapolated 
risks based on MACT allowable emissions in ``Estimation of MACT 
Allowable Emission Levels and Associated Risks and Impacts for the RTR 
Group 2A Source Categories'' in Docket No. EPA-HQ-OAR-2008-0008).
    For several source categories, no PB-HAP emissions were reported, 
while very low levels were reported for other source categories. Our 
analyses, based on these low levels of emissions, indicate these source 
categories do not pose potential for human health multipathway risks or 
adverse environmental impacts.
1. Epichlorohydrin Elastomers Production
    Lifetime maximum individual cancer risks associated with emissions 
modeled from the only one epichlorohydrin elastomer production facility 
are estimated to be less than 100-in-1 million. The highest maximum 
lifetime individual cancer risk was estimated at 30-in-1 million. The 
total estimated cancer incidence from this facility is 0.0004 excess 
cancer cases per year. We estimate that 4,000 people exposed to HAP 
from this source category may experience an increased individual 
lifetime cancer risk of greater than or equal to 1-in-1 million.
    We found no significant risk of adverse noncancer health effects 
associated with the modeled acute or chronic inhalation exposures from 
the Epichlorohydrin Elastomers Production source category. The maximum 
chronic noncancer TOSHI value associated with emissions from this 
epichlorohydrin elastomer production facility is 0.2, and the maximum 
acute screening HQ value was 0.1. There were no reported PB-HAP 
emissions for this source category. Our analysis, based on the absence 
of PB-HAP, indicates this source category does not pose potential for 
human health multipathway risks or adverse environmental impacts.
    These risks are based on reported actual emission levels. Our 
analysis of potential differences between actual emission levels and 
emissions allowable under the NESHAP indicated that actual and MACT 
allowable emission levels are approximately equal. Therefore, we expect 
no appreciable differences in risks with consideration of MACT 
allowable emission levels.
2. HypalonTM Production
    Lifetime maximum individual cancer risks associated with emissions 
modeled from the HypalonTM production facility are estimated 
to be less than 100-in-1 million. The highest maximum lifetime 
individual cancer risk was estimated at 1-in-1 million. The total 
estimated cancer incidence from this facility is 0.0004 excess cancer 
cases per year. We estimate that 400 people exposed to HAP from this 
source category may experience an increased individual lifetime cancer 
risk of greater than or equal to 1-in-1 million. We found no 
significant risk of adverse noncancer health effects associated with 
the modeled acute or chronic inhalation exposures from the 
HypalonTM Production source category. The maximum chronic 
noncancer TOSHI value associated with emissions from this 
HypalonTM production facility is 0.1, and the maximum acute 
screening HQ value was 0.7. There were no reported PB HAP emissions for 
this source category. Our analysis, based on the absence of PB HAP, 
indicates this

[[Page 60448]]

source category does not pose potential for human health multipathway 
risks or adverse environmental impacts.
    These risks are based on reported actual emission levels. Our 
analysis of potential differences between actual emission levels and 
emissions allowable under the NESHAP indicated that actual and MACT 
allowable emission levels are approximately equal. Therefore, we expect 
no appreciable differences in risks with consideration of MACT 
allowable emission levels.
3. Nitrile Butadiene Rubber Production
    All lifetime cancer risks associated with emissions modeled from 
the four NBR production facilities are estimated to be less than 100-
in-1 million. The highest maximum lifetime individual cancer risk was 
estimated at 60-in-1 million. We estimate that 47,000 people exposed to 
HAP from this source category may experience an increased individual 
lifetime cancer risk of greater than or equal to 1-in-1 million. The 
total estimated cancer incidence from these facilities is 0.004 excess 
cancer cases per year. We found no significant risk of adverse 
noncancer health effects associated with the modeled acute or chronic 
inhalation exposures from the Nitrile Butadiene Rubber Production 
source category. The maximum chronic noncancer TOSHI value associated 
with emissions from these NBR production facilities is 0.9, and the 
maximum acute screening HQ value for styrene is 0.3 (relative to the 
acute REL). The maximum HQ for acrylonitrile based on the highest acute 
threshold, the AEGL-1, was 0.07, so we do not have any concerns 
regarding potential acute impacts. There were no reported PB-HAP 
emissions for this source category. Our analysis, based on the absence 
of PB-HAP, indicates this source category does not pose potential for 
human health multipathway risks or adverse environmental impacts.
    These risks are based on reported actual emission levels. Our 
analysis of potential differences between actual emission levels and 
emissions allowable under the NESHAP indicated that actual and MACT 
allowable emission levels are approximately equal. Therefore, we expect 
no appreciable differences in risks with consideration of MACT 
allowable emission levels.
4. Polybutadiene Rubber Production
    All lifetime cancer risks associated with emissions modeled from 
the five PBR production facilities are estimated to be less than 100-
in-1 million. The highest maximum lifetime individual cancer risk was 
estimated at 10-in-1 million. The total estimated cancer incidence from 
these facilities is 0.002 excess cancer cases per year. We estimate 
that 16,000 people exposed to HAP from this source category may 
experience an increased individual lifetime cancer risk of greater than 
or equal to 1-in-1 million. We found no significant risk of noncancer 
health effects associated with the modeled acute or chronic inhalation 
exposures from the Polybutadiene Rubber Production source category. The 
maximum chronic noncancer TOSHI value associated with emissions from 
these PBR production facilities is 0.2, and the maximum acute screening 
HQ value was 0.3. There were no reported PB-HAP emissions for this 
source category. Our analysis, based on the absence of PB-HAP, 
indicates this source category does not pose potential for human health 
multipathway risks or adverse environmental impacts.
    These risks are based on reported actual emission levels. While we 
estimate that MACT allowable emissions could be as high as five times 
the actual emission levels, we expect no appreciable differences in 
risks between actual emission levels and emissions allowable under the 
NESHAP because over 99 percent of the HAP comprising the additional 
emissions attributable to MACT allowable emission levels have no cancer 
potency estimates and because the noncancer risk contribution from 
these additional emissions is minimal.
5. Styrene Butadiene Rubber and Latex Production
    All lifetime cancer risks associated with emissions modeled from 
the nine styrene butadiene rubber and latex production facilities are 
estimated to be less than 100-in-1 million. The highest maximum 
lifetime individual cancer risk was estimated at 7-in-1 million. The 
total estimated cancer incidence from these facilities is 0.004 excess 
cancer cases per year. We estimate that 26,000 people exposed to HAP 
from this source category may experience an increased individual 
lifetime cancer risk of greater than or equal to 1-in-1 million. We 
found no significant risk of adverse noncancer health effects 
associated with the modeled acute or chronic inhalation exposures from 
the Styrene Butadiene Rubber and Latex Production source category. The 
maximum chronic noncancer TOSHI value associated with emissions from 
these styrene butadiene rubber and latex production facilities is 0.1, 
and the maximum acute screening HQ value was 0.3. There were no 
reported PB-HAP emissions for this source category. Our analysis, based 
on the absence of PB-HAP, indicates this source category does not pose 
potential for human health multipathway risks or adverse environmental 
impacts.
    These risks are based on reported actual emission levels. While we 
estimate that MACT allowable emissions could be as high as five times 
the actual emission levels, we expect no appreciable differences in 
risks between actual emission levels and emissions allowable under the 
NESHAP because over 99 percent of the HAP comprising the additional 
emissions attributable to MACT allowable emission levels have no cancer 
potency estimates and because the noncancer risk contribution from 
these additional emissions is minimal.
6. Marine Vessel Loading Operations
    All individual lifetime cancer risks associated with emissions from 
the marine vessel loading operations facilities are estimated to be 
less than 100-in-1 million. The highest maximum lifetime individual 
cancer risk was estimated at 1-in-1 million. The total estimated cancer 
incidence from these facilities is 0.01 excess cancer cases per year. 
We estimate that 2,400 people exposed to HAP from this source category 
may experience an increased individual lifetime cancer risk of greater 
than or equal to 1-in-1 million. We found no significant risk of 
adverse noncancer health effects associated with the modeled acute or 
chronic inhalation exposures from the Marine Vessel Loading Operations 
source category. The maximum chronic noncancer TOSHI value associated 
with emissions from these marine vessel loading operations facilities 
is 0.006, and the maximum acute screening HQ value was 0.9 (using the 
REL). There were a few reported emissions of small amounts of PB-HAP 
including lead and POM. Our screening analysis, based on these low 
emission levels of PB-HAP, indicates this source category does not pose 
potential for human health multipathway risks or adverse environmental 
impacts.
    These risks are based on reported actual emission levels. Our 
analysis of potential differences between actual emission levels and 
emissions allowable under the NESHAP indicated that MACT allowable 
emission levels may be 2 to 10 times greater than actual emissions. 
Considering this difference, the highest maximum lifetime individual 
cancer risk could be as high as 10-in-1 million, the maximum chronic 
noncancer TOSHI value could be up to 0.06, and the maximum acute HQ 
value using the REL could be as high as 9. Considering MACT allowable 
emissions, we still do not expect

[[Page 60449]]

potential for human health multipathway risks or adverse environmental 
impacts, based on the very low emissions of PB-HAP.
7. Mineral Wool Production
    All lifetime cancer risks associated with emissions modeled from 
the eight mineral wool production facilities are estimated to be less 
than 100-in-1 million. The highest maximum lifetime individual cancer 
risk was estimated at 30-in-1 million. The total estimated cancer 
incidence from these facilities is 0.008 excess cancer cases per year. 
We estimate that 110,000 people exposed to HAP from this source 
category may experience an increased individual lifetime cancer risk of 
greater than or equal to 1-in-1 million. We found no significant risk 
of adverse noncancer health effects associated with the modeled chronic 
inhalation exposures. The maximum chronic noncancer TOSHI value 
associated with emissions from these mineral wool production facilities 
is 0.4. There were a few reported emissions of small amounts of PB-HAP 
including cadmium, lead, and mercury. Our screening analysis, based on 
these low emission levels of PB-HAP, indicates this source category 
does not pose potential for human health multipathway risks or adverse 
environmental impacts.
    Potential acute impacts of concern were identified in the acute 
inhalation screening assessment for facilities emitting formaldehyde 
and arsenic. Emissions of each of these pollutants showed the potential 
to create maximum offsite exceedances of acute screening HQ values of 
40 and 20 for formaldehyde and arsenic, respectively. One potential 
exceedance of the AEGL-1 value (HQAGEL-1 = 3.0) was 
identified for formaldehyde. No AEGL or ERPG values at any severity 
level are available for elemental arsenic, and this makes the 
interpretation of any potential exceedances of the arsenic REL more 
uncertain than when such values are available. Subsequent discussions 
with industry experts indicated that the continuous nature of the 
process would not lead to large fluctuations in the hourly emission 
rates, and that a more reasonable, yet still health-protective, ratio 
of peak-to-mean hourly emission rate is 2, rather than 10. (See 
emissions documentation in the ``Residual Risk for 9 Source 
Categories'' document in EPA Docket EPA-HQ-OAR-2008-0008). Application 
of this factor to our assessment still indicates the potential for 
acute concerns at two facilities, but reduces the maximum potential 
offsite impacts to HQ values of 8 and 4 based on the acute REL for 
formaldehyde and arsenic, respectively, and no HQ values exceeding 1 
based on the AEGL or ERPG values for formaldehyde (HQAEGL-1 
= HQERPG-1 = 0.7). Assuming peak hourly emissions occur 
throughout the year, meteorological conditions consistent with 
exceedances of the formaldehyde acute REL are estimated to occur 9 
percent of the time, and such conditions occur roughly 13 percent of 
the time for arsenic exceedances. Details on the refined acute 
assessment can be found in Appendix 7 of the ``Residual Risk Assessment 
for 9 Source Categories'' document. Further, under certain 
meteorological conditions, the potential to exceed the REL values for 
formaldehyde and arsenic exists even at average emission levels; this 
is estimated to potentially occur 7 percent of the time for 
formaldehyde and 4 percent of the time for arsenic. Exceedances of the 
formaldehyde REL indicate the potential for eye irritation; exceedances 
of the arsenic REL indicate the potential for effects to reproductive 
and developmental systems. In addition, the threshold exceedance was of 
the REL value only and not of the AEGL or ERPG values. As noted in the 
acute REL documentation, ``RELs are based on the most sensitive, 
relevant, adverse health effect reported in the medical and 
toxicological literature. RELs are designed to protect the most 
sensitive individuals in the population by the inclusion of margins of 
safety. Since margins of safety are incorporated to address data gaps 
and uncertainties, exceeding the REL does not automatically indicate an 
adverse health impact.''
    These risks are based on reported actual emission levels. Our 
analysis of potential differences between actual emission levels and 
emissions allowable under the NESHAP indicated that MACT allowable 
emission levels may be up to two times greater than actual emission 
levels. Considering this difference, the highest maximum lifetime 
individual cancer risk could be as high as 60-in-1 million, the maximum 
chronic noncancer TOSHI value could be up to 0.8, and the maximum acute 
HQ value could be as high as 16. Considering MACT allowable emissions, 
we do not expect potential for human health multipathway risks or 
adverse environmental impacts, based on the very low emissions of PB-
HAP.
8. Pharmaceuticals Production
    All lifetime cancer risks associated with emissions modeled from 
the 27 pharmaceuticals production facilities are estimated to be less 
than 100-in-1 million. The highest maximum lifetime individual cancer 
risk was estimated at 10-in-1 million. The total estimated cancer 
incidence from these facilities is 0.001 excess cancer cases per year. 
We estimate that 4,900 people exposed to HAP from this source category 
may experience an increased individual lifetime cancer risk of greater 
than or equal to 1-in-1 million. We found no significant risk of 
adverse noncancer health effects associated with the modeled chronic 
inhalation exposures. The maximum chronic noncancer TOSHI value 
associated with emissions from these pharmaceuticals production 
facilities is 0.2. There were a few reported emissions of small amounts 
of PB-HAP including lead, mercury, cadmium, and polynuclear aromatic 
hydrocarbons. Our screening analysis, based on these low emission 
levels of PB-HAP, indicates this source category does not pose 
potential for human health multipathway risks or adverse environmental 
impacts.
    The acute screening identified three facilities with a potential 
maximum HQ value greater than 1 based on REL values for three 
pollutants--methylene chloride, methanol, and chloroform--with maximum 
HQ values of 4, 3, and 2, respectively. We also estimated a maximum HQ 
value of 2 for acetonitrile based on the AEGL-1 level. For the 
facilities that exceeded acute thresholds in the screening assessment, 
we refined the assessment by plotting receptors on facility aerial 
photographs and determining maximum offsite concentrations. Once we 
performed these refinements, estimated maximum offsite concentrations 
were seen to exceed acute REL values at one facility, and there were no 
exceedances of the AEGL-1 levels for acetonitrile (HQAEGL-1 
= 0.5). The highest offsite concentration of chloroform exceeds the REL 
by a factor of 2 (HQREL = 2, HQAEGL-1 = 0.04). At 
this facility, meteorological conditions leading to offsite exceedances 
of the REL could occur as frequently as 13 hours per year, or about 0.1 
percent of the time. HQ values from the refined assessment did not 
exceed 1 for either methylene chloride (HQREL = 1, 
HQAEGL-1 = 0.03) or methanol (HQREL = 0.9, 
HQAEGL-1 = 0.04). The threshold exceedance was of the REL 
value for chloroform only. As noted in the acute REL documentation, 
``RELs are based on the most sensitive, relevant, adverse health effect 
reported in the medical and toxicological literature. RELs are designed 
to protect the most sensitive individuals in the population by the 
inclusion of margins of safety. Since margins of safety are 
incorporated to address data gaps and uncertainties, exceeding the REL 
does

[[Page 60450]]

not automatically indicate an adverse health impact.'' Details on the 
refined acute assessment can be found in Appendix 7 of the ``Residual 
Risk Assessment for 9 Source Categories'' document.
    These risks are based on reported actual emission levels. Our 
analysis of potential differences between actual emission levels and 
emissions allowable under the NESHAP indicated that MACT allowable 
emission levels may be up to 25 percent greater than actual emission 
levels. Considering this difference, the highest maximum lifetime 
individual cancer risk could be as high as 13-in-1 million, the maximum 
chronic noncancer TOSHI value could be up to 0.3, and the maximum acute 
HQ value could be as high as 3. Considering MACT allowable emission 
levels, we do not expect potential for human health multipathway risks 
or adverse environmental impacts, based on the very low emissions of 
PB-HAP.
9. Printing and Publishing Industry
    All lifetime cancer risks associated with emissions modeled from 
the 179 printing and publishing industry facilities are estimated to be 
less than 100-in-1 million. The highest maximum lifetime individual 
cancer risk was estimated at 0.05-in-1 million. The total estimated 
cancer incidence from these facilities is 0.000009 excess cancer cases 
per year. We estimate that no one exposed to HAP from this source 
category will experience an increased individual lifetime cancer risk 
of greater than or equal to 1-in-1 million. We found no significant 
risk of adverse noncancer health effects associated with the modeled 
chronic inhalation exposures. The maximum chronic noncancer TOSHI value 
associated with emissions from these printing and publishing facilities 
is 0.08. There were a few reported emissions of small amounts of PB-HAP 
including cadmium, lead, mercury, and POM. Our screening analysis, 
based on these low emission levels of PB-HAP, indicates this source 
category does not pose potential for human health multipathway risks or 
adverse environmental impacts.
    The screening assessment for acute impacts suggests that short-term 
toluene concentrations at seven of the publication rotogravure 
facilities modeled could exceed the acute REL thresholds for toluene, 
assuming worst-case meteorological conditions are present, using our 
default assumption that the maximum hourly emissions of toluene exceed 
the average hourly emission rate by a factor of ten, and using a 
default source to receptor distance of 100 meters. Emissions of toluene 
showed the potential to create maximum hourly concentrations which 
could exceed the acute REL by a factor of 20 (HQREL = 20) 
and potentially reach the level of the AEGL-1 (HQAEGL-1 = 
1). Additionally, because there is no REL, AEGL, or ERPG value 
available for ethylene glycol, which was reported as being emitted from 
this source category, we used the acute MRL value as an acute reference 
value for screening. The results of this additional assessment 
indicated that 4 facilities showed the potential to exceed the MRL for 
ethylene glycol by as much as a factor of 3 (HQMRL = 3). As 
noted in the documentation for MRL values, ``exceeding the MRL does not 
automatically indicate an adverse health impact.'' We also note that, 
since MRL values can be applied to exposure durations up to 14 days, 
these estimated MRL exceedances are likely to be overestimated.
    For the publication rotogravure facilities that exceeded acute 
toluene thresholds in the screening assessment, we refined the 
assessment by plotting receptors on facility aerial photographs and 
determining maximum offsite concentrations. Once we performed these 
refinements, estimated maximum offsite concentrations were seen to 
exceed the acute REL at six publication rotogravure facilities. The 
highest offsite concentration exceeds the REL by a factor of 10 
(HQREL = 10) and is about half of the AEGL-1 value 
(HQAEGL-1 = 0.5). This occurs near a public road north of a 
facility. At this facility, meteorological conditions leading to 
offsite exceedances of the REL could occur as frequently as 90 hours 
per year, or about 1 percent of the time. At the facility where we 
estimate the REL to be most frequently exceeded, the maximum REL 
exceedance is by a factor of 4 (HQREL = 4), and 
meteorological conditions leading to offsite exceedances of the REL 
could occur as frequently as 138 hours per year, or about 2 percent of 
the time.
    Thus, the highest offsite concentration exceeds the REL by a factor 
of 10 (HQREL = 10) and the threshold exceedance was of the 
REL value only. As noted in the acute REL documentation, ``RELs are 
based on the most sensitive, relevant, adverse health effect reported 
in the medical and toxicological literature. RELs are designed to 
protect the most sensitive individuals in the population by the 
inclusion of margins of safety. Since margins of safety are 
incorporated to address data gaps and uncertainties, exceeding the REL 
does not automatically indicate an adverse health impact.'' Further, 
based on the extensive information we have on this source category and 
on engineering judgment, we estimate that a factor of 10 emissions 
multiplier is most likely high for publication rotogravure printing. 
Instead of 10, we believe a more appropriate multiplier would be 5 or 
less. Using a multiplier of 5 (or less) would reduce the estimated 
acute impacts by half or more from the values presented. Details on the 
refined acute assessment can be found in Appendix 7 of the ``Residual 
Risk for 9 Source Categories'' document (See Docket EPA-HQ-OAR-2008-
0008).
    These risks are based on reported actual emission levels. Our 
analysis of potential differences between actual emission levels and 
emissions allowable under the NESHAP indicated that MACT allowable 
emission levels may be up to five times greater than actual emission 
levels. Considering this difference, the highest maximum lifetime 
individual cancer risk could be as high as 0.3-in-1 million, the 
maximum chronic noncancer TOSHI value could be up to 0.4, and the 
maximum acute HQ value could be as high as 50. Considering MACT 
allowable emission levels, we do not expect potential for human health 
multipathway risks or adverse environmental impacts, based on the very 
low emissions of PB-HAP.

F. What are our proposed decisions on acceptability and ample margin of 
safety?

    Section 112(f) of the CAA requires that EPA promulgate standards 
for a category if promulgation of such standards is required to provide 
an ample margin of safety to protect public health or to prevent, 
taking into consideration costs, energy, safety, and other relevant 
factors, an adverse environmental effect. In determining whether 
standards are required to provide an ample margin of safety to protect 
public health, EPA considers both maximum individual cancer risk and 
risk of non-cancer health effects posed by emissions from the source 
category, as well as any other relevant public health-related 
information or factors. With regard to maximum individual cancer risk, 
the CAA states that if the MACT standards ``do not reduce lifetime 
excess cancer risks [due to HAP emissions] to the individual most 
exposed to emissions from a source in the category or subcategory to 
less than one in one million,'' EPA must promulgate residual risk 
standards for the source category (or subcategory) as necessary to 
provide an ample margin of safety.

[[Page 60451]]

    As discussed in greater detail below, cancer risks to the 
individual most exposed to emissions from the Printing and Publishing 
source category are estimated to be below 1-in-1 million. After 
considering this information as well as an analysis of non-cancer 
health effects and environmental effects, we have determined that the 
current MACT standard provides an ample margin of safety to protect 
public health and prevents an adverse environmental effect. In reaching 
this conclusion, we did not consider costs.
    For each of the other source categories that are the subject of 
today's proposed rulemaking, we estimated that risks to the individual 
most exposed to emissions from the category are 1-in-1 million or 
greater. Following our initial determination that excess lifetime 
individual cancer risk to the individual most exposed to emissions from 
the category considered exceeds 1-in-1 million, our approach to 
developing residual risk standards is based on a two-step determination 
of acceptable risk and ample margin of safety. The first step, 
determining whether risks are acceptable, is only a starting point for 
the analysis that determines a final standard. The second step 
determines an ample margin of safety, which is the level at which the 
standard is set.
    In the Benzene NESHAP, we explained that we will generally presume 
that if the risk to an individual exposed to the maximum level of a 
pollutant for a lifetime (the MIR) is no higher than approximately 1 in 
10 thousand (100-in-1 million), that risk level is considered 
acceptable. However, in determining acceptability we weigh the 
magnitude of the MIR with a series of other health measures and 
factors, including overall incidence of cancer or other serious health 
effects within the exposed population, the numbers of persons exposed 
within each individual lifetime risk range and associated incidence 
within, typically, a 50 km exposure radius around facilities, the 
science policy assumptions and estimation uncertainties associated with 
the risk measures, weight of the scientific evidence for human health 
effects, and other quantified or unquantified health effects. Based on 
the maximum individual cancer risk estimates and other health factors 
evaluated for the nine source categories, we have concluded that the 
residual risk for these source categories is acceptable.
    EPA must consider health and risk factors, as well as costs and 
economic impacts, technological feasibility, and other factors relevant 
to each particular decision, to complete an overall judgment on whether 
the public health is protected with an ample margin of safety. Because 
our analyses suggest risks to the individual most exposed to emissions 
equal or exceed 1-in-1 million after application of the NESHAP for the 
source categories other than Printing and Publishing, we considered the 
feasibility and costs of additional controls to reduce emissions and 
associated risks to address whether additional controls were necessary 
to provide an ample margin of safety for these categories. For each 
source category (with the exception of the Printing and Publishing), we 
identified emissions reduction options for each emission point 
contributing significantly to the risks and evaluated the costs and 
emission reduction benefits of these options. These analyses can be 
found in impacts assessment documents for each NESHAP, which are 
available in the docket.
    We did not consider facility-wide risk. Although we believe we can 
consider facility-wide risk as a relevant factor in determining an 
ample margin of safety, we do not have cost, technical feasibility, and 
other data to analyze emission sources at the facility that are outside 
the source category for the nine source categories in RTR Group 2A.
    The sections below and the impact memos in docket EPA-HQ-OAR-2008-
0008 provide more detailed discussions about the emissions reduction 
options, the impacts of the emissions reduction options, and our ample 
margin of safety decision for each of the nine source categories.
 1. Epichlorohydrin Elastomers Production
    For the Epichlorohydrin Elastomers Production source category, we 
identified only one control option to address risks from equipment 
leaks, which were shown to drive the maximum individual cancer risks 
for this source category. This control option would require sources to 
install leakless valves to prevent leaks from those components.
    We estimated HAP reduction resulting from this control option is 
about 0.4 tons per year from the baseline actual emissions level. We 
estimated that achieving these reductions would involve a capital cost 
of about $725,000, a total annualized cost of about $99,000, and a 
cost-effectiveness of $244,000 per ton of HAP emissions reduced.
    Based on actual emissions, we estimate the maximum individual 
lifetime cancer risk is 30-in-1 million, the annual cancer incidence is 
0.0004, and the population exposed to individual lifetime cancer risk 
of greater than or equal to 1-in-1 million is 4,000. The additional 
control requirement would achieve approximately 10 percent reduction of 
all three of these cancer risk metrics at a very high cost. Further, 
the analysis based on actual emission levels has shown that both the 
chronic and acute noncancer hazards are below the threshold value of 1, 
indicating little or no potential for noncancer health effects 
resulting from actual emissions from the Epichlorohydrin Elastomers 
Production source category. We estimate that the MACT allowable 
emissions from this source category are approximately equal to the 
reported, actual emissions. Therefore, the estimated emission 
reduction, costs, and risk reduction discussed above would also be 
applicable to the MACT allowable emissions level. As a result, we 
propose that, based on actual and MACT allowable emissions, the 
existing MACT standard provides an ample margin of safety (considering 
cost, technical feasibility, and other factors) to protect public 
health.
    We are also required to consider the potential for adverse impacts 
to the environment as part of a residual risk assessment. We believe 
that human toxicity values for the inhalation pathway are generally 
protective of terrestrial mammals. Because the maximum cancer and 
noncancer hazards to humans from inhalation exposure are relatively 
low, we expect there to be no potential for significant and widespread 
adverse effect to terrestrial mammals from inhalation exposure to HAP 
emitted from the Epichlorohydrin Elastomers Production source category. 
As this source category had no reported PB-HAP emissions, no potential 
for an adverse environmental effect exists. Because our results showed 
no potential for any adverse environmental effect, we also do not 
believe there is any potential for an adverse effect on threatened or 
endangered species or on their critical habitat within the meaning of 
50 CFR 402.14(a). With these results, we have concluded that a 
consultation with the Fish and Wildlife Service is not necessary.
    In summary, we propose that the current MACT standard provides an 
ample margin of safety to protect public health. The additional control 
available is not cost-effective in light of the additional health 
protection against maximum individual cancer risk and chronic and acute 
noncancer hazards that the control would provide. In addition, we 
believe that there is no potential for adverse environmental effects. 
Thus, we are proposing to re-

[[Page 60452]]

adopt the existing MACT standard to satisfy section 112(f) of the CAA.
2. HypalonTM Production
    For the HypalonTM Production source category, we 
identified only one control option to address risks from back-end 
operations, which were shown to drive the maximum individual cancer 
risks for this source category. This control option would require HAP 
emissions reduction through pollution prevention or other measures for 
these operations. We estimated HAP reduction resulting from this 
control option is about 3.7 tons per year from the baseline actual 
emissions level. We estimated that achieving these reductions would 
involve a capital cost of about $3,500,000, a total annualized cost of 
about $1,900,000, and a cost-effectiveness of $521,000 per ton of HAP 
emissions reduced.
    Based on actual emissions, we estimate the maximum individual 
lifetime cancer risk is 1-in-1 million, the annual cancer incidence is 
0.0004, and the population exposed to individual lifetime cancer risk 
of greater than or equal to 1-in-1 million is 400. The additional 
control requirement would achieve approximately 20 percent reduction of 
all three of these cancer risk metrics at a very high cost. Further, 
the analysis based on actual emission levels has shown that both 
chronic and acute noncancer hazards are below the threshold value of 1, 
indicating little or no potential for noncancer health effects 
resulting from actual emissions from the HypalonTM 
Production source category. We estimate that the MACT allowable 
emissions from this source category are approximately equal to the 
reported, actual emissions. Therefore, the estimated emission 
reduction, costs, and risk reduction discussed above would also be 
applicable to the MACT allowable emissions level. As a result, we 
propose that, based on actual and MACT allowable emissions, the 
existing MACT standard provides an ample margin of safety (considering 
cost, technical feasibility, and other factors) to protect public 
health.
    We are also required to consider the potential for adverse impacts 
to the environment as part of a residual risk assessment. As previously 
noted, we believe that human toxicity values for the inhalation pathway 
are generally protective of terrestrial mammals. Because the maximum 
cancer and noncancer hazards to humans from inhalation exposure are 
relatively low, we expect there to be no potential for significant and 
widespread adverse effect to terrestrial mammals from inhalation 
exposure to HAP emitted from the HypalonTM Production source 
category. As this source category had no reported PB-HAP emissions, no 
potential for an adverse environmental effect exists. Because our 
results showed no potential for an adverse environmental effect, we 
also do not believe there is any potential for an adverse effect on 
threatened or endangered species or on their critical habitat within 
the meaning of 50 CFR 402.14(a). With these results, we have concluded 
that a consultation with the Fish and Wildlife Service is not 
necessary.
    In summary, we propose that the current MACT standard provides an 
ample margin of safety to protect public health. The additional control 
available is not cost effective in light of the additional health 
protection against maximum individual cancer risk and chronic and acute 
noncancer hazard the control would provide. In addition, we believe 
that there is no potential for adverse environmental effect. Thus, we 
are proposing to re-adopt the existing MACT standard to satisfy section 
112(f) of the CAA.
3. Nitrile Butadiene Rubber Production
    For the Nitrile Butadiene Rubber Production source category, we 
identified two control options; one to address risks from front-end 
process vent emissions and another to address risks from equipment leak 
emissions. Emissions from these sources were shown to drive the maximum 
individual cancer risk for this source category. The control option for 
front-end process vents would require controls to be placed on more 
vents by expanding the applicability of the current control 
requirements, and the control option for equipment leaks would involve 
a requirement to install leakless valves to prevent leaks from those 
components. We estimated HAP reduction resulting from additional front-
end process vent controls is about 14.9 tons per year from the baseline 
actual emissions level. We estimated that achieving these reductions 
would involve a capital cost of about $310,000, a total annualized cost 
of about $750,000, and a cost-effectiveness of $50,000 per ton of HAP 
emissions reduced. We estimated HAP reduction resulting from additional 
equipment leak controls is about 3.7 tons per year from the baseline 
actual emissions level. We estimated that achieving these reductions 
would involve a capital cost of about $6,600,000, a total annualized 
cost of about $910,000, and a cost-effectiveness of $244,000 per ton of 
HAP emissions reduced.
    Based on actual emissions, we estimate the maximum individual 
lifetime cancer risk is 60-in-1 million, the annual cancer incidence is 
0.004, and the population exposed to individual lifetime cancer risk of 
greater than or equal to 1-in-1 million is 47,000. The additional 
control requirement would achieve approximately 25 percent reduction of 
all three of these cancer risk metrics at a very high cost. Further, 
the analysis based on actual emission levels has also shown that both 
the chronic and acute noncancer hazards are below the threshold value 
of 1, indicating little or no potential for noncancer health effects 
resulting from actual emissions from the Nitrile Butadiene Rubber 
source category. We estimate that the MACT allowable emissions from 
this source category are approximately equal to the reported, actual 
emissions. Therefore, the estimated emission reduction, costs, and risk 
reduction discussed above would also be applicable to the MACT 
allowable emissions level. As a result, we propose that the existing 
MACT standard, based on actual and MACT allowable emissions, provides 
an ample margin of safety (considering cost, technical feasibility, and 
other factors) to protect public health.
    We are also required to consider the potential for adverse impacts 
to the environment as part of a residual risk assessment. As previously 
noted, we believe that human toxicity values for the inhalation pathway 
are generally protective of direct impacts on terrestrial mammals and 
plants. Because the maximum cancer and noncancer hazards to humans from 
inhalation exposure are relatively low, we expect there to be no 
potential for significant and widespread adverse effect to terrestrial 
mammals from inhalation exposure to HAP emitted from the Nitrile 
Butadiene Rubber Production source category. As this source category 
had no reported PB-HAP emissions, no potential for an adverse effect 
exists. Because our results showed no potential for an adverse 
environmental effect, we also do not believe there is any potential for 
an adverse effect on threatened or endangered species or on their 
critical habitat within the meaning of 50 CFR 402.14(a). With these 
results, we have concluded that a consultation with the Fish and 
Wildlife Service is not necessary.
    In summary, we propose that the current MACT standard provides an 
ample margin of safety to protect public health. The additional control 
available is not cost effective in light of the additional health 
protection against maximum individual cancer risk and

[[Page 60453]]

chronic and acute noncancer hazard the control would provide. In 
addition, we believe that there is no potential for adverse 
environmental effect. Thus, we are proposing to re-adopt the existing 
MACT standard to satisfy section 112(f) of the CAA.
4. Polybutadiene Rubber Production
    For the Polybutadiene Rubber Production source category, we 
identified two control options; one to address risks from front-end 
process vent emissions and another to address risks from equipment leak 
emissions. Emissions from these sources were shown to drive the maximum 
individual cancer risk for this source category. The control option for 
front-end process vents would require controls to be placed on more 
vents by expanding the applicability of the current control 
requirements, and the control option for equipment leaks would involve 
a requirement to install leakless valves to prevent leaks from those 
components.
    We estimated HAP reduction resulting from additional front-end 
process vent controls is about 178 tons per year from the baseline 
actual emissions level. We estimated that achieving these reductions 
would involve a capital cost of about $310,000, a total annualized cost 
of about $750,000, and a cost-effectiveness of $4,000 per ton of HAP 
emissions reduced. We estimated HAP reduction resulting from additional 
equipment leak controls is about 52 tons per year from the baseline 
actual emissions level. We estimated that achieving these reductions 
would involve a capital cost of about $93,000,000, a total annualized 
cost of about $13,000,000, and a cost-effectiveness of $244,000 per ton 
of HAP emissions reduced.
    Based on actual emissions, we estimate the maximum individual 
lifetime cancer risk is 10-in-1 million, the annual cancer incidence is 
0.002, and the population exposed to individual lifetime cancer risk of 
greater than or equal to 1-in-1 million is 16,000. The additional 
control requirement would achieve approximately 10 percent reduction of 
all three of these cancer risk metrics at a relatively high cost 
considering that risks are low under the current MACT standard and that 
the reduction in risks is relatively small. Further, the analysis based 
on actual emissions has shown that both the chronic and acute noncancer 
hazards are below the threshold value of 1.
    We estimate that the MACT allowable emissions from this source 
category are as high as five times actual emission levels. However, the 
additional emissions represented by the MACT allowable emissions level 
are released from a part of the production process that does not 
contribute appreciably to the risks and for which the control option 
would not affect emission levels. Therefore, we believe that the 
estimated emission reductions, costs, and risk reduction discuss above 
would also be applicable to the MACT allowable emissions level. As a 
result, we propose that, based on actual and MACT allowable emission 
levels, the existing MACT standard provides an ample margin of safety 
(considering cost, technical feasibility, and other factors) to protect 
public health.
    We are also required to consider the potential for adverse impacts 
to the environment as part of a residual risk assessment. As previously 
noted, we believe that human toxicity values for the inhalation pathway 
are generally protective of terrestrial mammals. Because the maximum 
cancer and noncancer hazards to humans from inhalation exposure are 
relatively low, we expect there to be no potential for significant and 
widespread adverse effect to terrestrial mammals from inhalation 
exposure to HAP emitted from the Polybutadiene Rubber Production source 
category. As this source category had no reported PB-HAP emissions, no 
potential for an adverse effect exists. Because our results showed no 
potential for an adverse environmental effect, we also do not believe 
there is any potential for an adverse effect on threatened or 
endangered species or on their critical habitat within the meaning of 
50 CFR 402.14(a). With these results, we have concluded that a 
consultation with the Fish and Wildlife Service is not necessary.
    In summary, we propose that the current MACT standard provides an 
ample margin of safety to protect public health. The additional control 
available is not cost-effective in light of the additional health 
protection against maximum individual cancer risk and chronic and acute 
noncancer hazard the control would provide. In addition, we believe 
that there is no potential for adverse environmental effect. Thus, we 
are proposing to re-adopt the existing MACT standard to satisfy section 
112(f) of the CAA.
5. Styrene Butadiene Rubber and Latex Production
    For the Styrene Butadiene Rubber and Latex Production source 
category, we identified one available control option to address risks 
from equipment leaks, which were shown to drive the maximum individual 
cancer risks for this source category. This control option would 
involve a requirement to install leakless valves to prevent leaks from 
those components.
    We estimated HAP reduction resulting from installing leakless 
valves is about 6 tons per year from the baseline actual emissions 
level. We estimated that achieving these reductions would involve a 
capital cost of about $10,600,000, a total annualized cost of about 
$1,500,000, and a cost-effectiveness of $244,000 per ton of HAP 
emissions reduced.
    Based on actual emissions, we estimate the maximum individual 
lifetime cancer risk is 7-in-1 million, the annual cancer incidence is 
0.004, and the population exposed to individual lifetime cancer risk of 
greater than or equal to 1-in-1 million is 26,000. The additional 
control requirement would achieve approximately 25 percent reduction of 
all three of these cancer risk metrics at a relatively high cost. 
Further, the analysis based on actual emissions has shown that both the 
chronic and acute noncancer hazards are below the threshold value of 1.
    We estimate that the MACT allowable emissions from this source 
category are as high as four times actual emission levels. However, the 
additional emissions represented by the MACT allowable emissions level 
are released from a part of the production process that does not 
contribute appreciably to the risks and for which the control option 
would not affect emission levels. Therefore, we believe that the 
estimated emission reductions, costs, and risk reduction discussed 
above would also be applicable to the MACT allowable emissions level. 
As a result, we propose that, based on actual and MACT allowable 
emission levels, the existing MACT standard provides an ample margin of 
safety (considering cost, technical feasibility, and other factors) to 
protect public health.
    We are also required to consider the potential for adverse impacts 
to the environment (as part of a residual risk assessment. As 
previously noted, we believe that human toxicity values for the 
inhalation pathway are generally protective of terrestrial mammals. 
Because the maximum cancer and noncancer hazards to humans from 
inhalation exposure are relatively low, we expect there to be no 
potential for significant and widespread adverse effect to terrestrial 
mammals from inhalation exposure to HAP emitted from the Styrene 
Butadiene Rubber and Latex Production source category. As this source 
category had no reported PB-HAP emissions, no potential for an adverse 
effect was identified. Since our results showed no potential for an

[[Page 60454]]

adverse environmental effect, we also do not believe there is any 
potential for an adverse effect on threatened or endangered species or 
on their critical habitat within the meaning of 50 CFR 402.14(a). With 
these results, we have concluded that a consultation with the Fish and 
Wildlife Service is not necessary.
    In summary, we propose that the current MACT standard provides an 
ample margin of safety to protect public health. The additional control 
available is not cost-effective in light of the additional health 
protection against maximum individual cancer risk and chronic and acute 
noncancer hazard the control would provide. In addition, we believe 
that there is no potential for adverse environmental effect. Thus, we 
are proposing to re-adopt the existing MACT standard to satisfy section 
112(f) of the CAA.
6. Marine Vessel Loading Operations
    For the Marine Vessel Loading Operations source category, we 
identified one control option to address risks from ethylene dichloride 
emissions, which were shown to drive the maximum individual cancer 
risks for this source category. This control option would require the 
same performance standard specified in the original MACT standard to be 
used at more facilities by lowering the applicability limit for 
ethylene dichloride emissions from 10 tons per year to approximately 
2.6 tons per year. We estimated HAP reduction resulting from this 
control option is about 15 tons per year from the baseline actual 
emissions level. We estimated that achieving these reductions would 
involve a capital cost of about $57,000,000, a total annualized cost of 
about $11,000,000, and a cost-effectiveness of over $700,000 per ton of 
HAP emissions reduced.
    Based on actual emissions, we estimate the maximum individual 
lifetime cancer risk is 1-in-1 million, the annual cancer incidence is 
0.01, and the population exposed to individual lifetime cancer risk of 
greater than or equal to 1-in-1 million is 2,400. The additional 
control requirement would achieve approximately 5 percent reduction of 
all three of these cancer risk metrics at a very high cost. The 
analysis based on actual emission levels has also shown that both the 
chronic and acute noncancer risks are below the threshold value of 1.
    We estimate that the MACT allowable emissions from this source 
category could be 10 times the reported actual emissions, which could 
potentially result in risk impacts up to 10 times those estimated for 
the actual emissions level. Assuming all impacts were proportional to 
those predicted for actual emissions, this control option would result 
in an emission reduction of around 150 tons per year (based on a factor 
of 10). The risk reduction would still be minimal. The cost would not 
differ, resulting in a cost effectiveness of around $700,000 per ton 
based on MACT allowable emissions.
    As a result, we propose that, based on actual and MACT allowable 
emissions, the existing MACT standard provides an ample margin of 
safety (considering cost, technical feasibility, and other factors) to 
protect public health.
    We are also required to consider the potential for adverse impacts 
to the environment as part of a residual risk assessment. As previously 
noted, we believe that human toxicity values for the inhalation pathway 
are generally protective of terrestrial mammals. Because the maximum 
cancer and noncancer hazards to humans from inhalation exposure are 
relatively low, we expect there to be no significant and widespread 
adverse effect to terrestrial mammals from inhalation exposure to HAP 
emitted from the Marine Vessel Loading Operations source category. To 
assess the potential for adverse effect to other wildlife, we have 
carried out a screening-level assessment of adverse environmental 
effects via exposure to PB-HAP emissions. This source category reported 
PB-HAP emissions, but, based on our application of the screening 
scenario developed for TRIM.FaTE model, no potential for an adverse 
environment effect via multipathway exposures was identified. Because 
our results showed no potential for an adverse environmental effect, we 
also do not believe there is any potential for an adverse effect on 
threatened or endangered species or on their critical habitat within 
the meaning of 50 CFR 402.14(a). With these results, we have concluded 
that a consultation with the Fish and Wildlife Service is not 
necessary.
    In summary, we propose that the current MACT standard provides an 
ample margin of safety to protect public health. The additional control 
available is not cost-effective in light of the additional health 
protection against maximum individual cancer risk and chronic and acute 
noncancer hazard the control would provide. In addition, we believe 
that there is no potential for adverse environmental effect. Thus, we 
are proposing to re-adopt the existing MACT standard to satisfy section 
112(f) of the CAA.
7. Mineral Wool Production
    For the Mineral Wool Production source category, we identified one 
available control option to address risks from fiber collection and 
cooling chambers, the emission points which were shown to drive the 
maximum individual cancer risks for this source category. This control 
option would require sources to add thermal incinerators to control 
emissions from these areas.
    We estimated HAP reduction resulting from this control option is 
about 48 tons per year from the baseline actual emissions level. We 
estimated that achieving these reductions would involve a capital cost 
of about $65,000,000, a total annualized cost of about $13,000,000, and 
a cost-effectiveness of $270,000 per ton of HAP emissions reduced.
    Based on actual emissions, we estimate the maximum individual 
lifetime cancer risk is 30-in-1 million, the annual cancer incidence is 
0.008, and the population exposed to individual lifetime cancer risk of 
greater than or equal to 1-in-1 million is 110,000. The additional 
control requirement would achieve less than 10 percent reduction of all 
three of these cancer risk metrics at a very high cost. The analysis 
has also shown that the chronic noncancer hazards are low based on 
actual emissions. While the refined assessment for acute impacts using 
actual emission suggests that short-term arsenic and formaldehyde 
concentrations at five modeled facilities could exceed their acute REL 
values by as much as factors of 4 and 8, respectively, if worst-case 
meteorological conditions (which occur roughly 10 percent of the time) 
are present at the same time that maximum hourly emissions of these 
chemicals exceed the average hourly emission rate by a factor of 2. 
However, as noted earlier in this preamble, exceedances of these REL 
values may occur even at average emission rates for roughly 10 percent 
of the hours in a year. In addition, the threshold exceedance was of 
the REL value only. As noted in the acute REL documentation, ``RELs are 
based on the most sensitive, relevant, adverse health effect reported 
in the medical and toxicological literature. RELs are designed to 
protect the most sensitive individuals in the population by the 
inclusion of margins of safety. Since margins of safety are 
incorporated to address data gaps and uncertainties, exceeding the REL 
does not automatically indicate an adverse health impact.''

[[Page 60455]]

    We estimate that the MACT allowable emissions from this source 
category could be as high as two times the reported actual emissions, 
which could potentially result in risk impacts double those estimated 
for the actual emissions level. Assuming all impacts were proportional 
to those predicted for actual emissions, this incinerator control 
option would result in an emission reduction of around 96 tons per year 
and a risk reduction of approximately 20 percent. The cost would not 
differ, resulting in a cost effectiveness of around $135,000 per ton 
based on MACT allowable emissions. Finally, the REL value for arsenic 
is designed for a four hour exposure whereas the exposure duration used 
in the modeling scenario was one hour, making the use of the REL in 
this application more protective of human health than if the exposure 
durations were the same. Considering these factors, although we cannot 
completely rule out the potential for acute impacts from formaldehyde 
or arsenic at these facilities, we believe it to be unlikely any acute 
health impacts would actually occur. As a result, we propose that, 
based on actual and MACT allowable emissions levels, the existing MACT 
standard, provides an ample margin of safety (considering cost, 
technical feasibility, and other factors) to protect public health.
    We are also required to consider the potential for adverse impacts 
to the environment as part of a residual risk assessment. As previously 
noted, we believe that human toxicity values for the inhalation pathway 
are generally protective of terrestrial mammals. Because the maximum 
cancer and noncancer hazards to humans from inhalation exposure are 
relatively low, we expect there to be no potential for significant and 
widespread adverse effect to terrestrial mammals from inhalation 
exposure to HAP emitted from the Mineral Wool Production source 
category. To evaluate the potential for adverse effects to other 
wildlife, we carried out a screening-level assessment of adverse 
environmental effects via exposure to PB-HAP emissions. This source 
category reported PB-HAP emissions, but, based on our application of 
the screening scenario developed for TRIM.FaTE model, no potential for 
an adverse environment effect via multipathway exposures was 
identified. Because our results showed no potential for an adverse 
environmental effect, we also do not believe there is any potential for 
an adverse effect on threatened or endangered species or on their 
critical habitat within the meaning of 50 CFR 402.14(a). With these 
results, we have concluded that a consultation with the Fish and 
Wildlife Service is not necessary.
    In summary, we propose that the current MACT standard provides an 
ample margin of safety to protect public health. The additional control 
available is not cost-effective in light of the additional health 
protection against maximum individual cancer risk and chronic and acute 
noncancer hazard the control would provide. In addition, we believe 
that there is no potential for adverse environmental effect. Thus, we 
are proposing to re-adopt the existing MACT standard to satisfy section 
112(f) of the CAA.
8. Pharmaceuticals Production
    For the Pharmaceuticals Production source category, we identified 
one available control option to address risks from equipment leaks, 
which were shown to drive the maximum individual cancer risks for this 
source category. This control option would involve a work practice 
requirement to monitor valves monthly until fewer than 0.5 percent of 
valves are leaking.
    We estimated HAP reduction resulting from this control option is 
about 107 tons per year from the baseline actual emissions level. We 
estimated that achieving these reductions would involve no capital 
costs, a total annualized cost of about $820,000, and a cost-
effectiveness of $7,600 per ton of HAP emissions reduced.
    Based on actual emissions, we estimate the maximum individual 
lifetime cancer risk is 10-in-1 million, the annual cancer incidence is 
0.001, and the population exposed to individual lifetime cancer risk of 
greater than or equal to 1-in-1 million is 4,900. The application of 
the additional control option would reduce all three of these 
relatively low cancer risks metrics by less than 10 percent. We propose 
that the costs for this option are disproportionate to the limited 
cancer health benefit potentially achievable with the controls. 
Further, the analysis has also shown that both the chronic and acute 
noncancer hazards are low, based on actual emissions. While the 
assessment for acute impacts using actual emissions suggests that 
short-term chloroform concentrations at one modeled facility could 
exceed the acute threshold, this is only if worst-case meteorological 
conditions are present (estimated at roughly 0.1 percent of the year) 
at the same time that maximum hourly emissions of these chemicals 
exceed the average actual hourly emission rate by a factor of 5. In 
addition, the threshold exceedance was of the REL value only. As noted 
in the acute REL documentation, ``RELs are based on the most sensitive, 
relevant, adverse health effect reported in the medical and 
toxicological literature. RELs are designed to protect the most 
sensitive individuals in the population by the inclusion of margins of 
safety. Since margins of safety are incorporated to address data gaps 
and uncertainties, exceeding the REL does not automatically indicate an 
adverse health impact.'' Finally, the REL value for chloroform (the 
only HAP with the potential for acute impacts in the refined analysis) 
is designed for a 7-hour exposure, whereas the exposure duration used 
in the modeled scenario was 1 hour, making the uses of the REL in this 
application more protective of human health than if the exposure 
durations were the same. Considering these factors, we believe it to be 
unlikely any acute health impacts would actually occur.
    We estimate that the MACT allowable emissions from this source 
category could be as much as 25 percent higher than the reported actual 
emissions, which could potentially result in risk impacts 25 percent 
higher than those estimated for the actual emissions level. Assuming 
all impacts are proportional to those predicted for actual emissions, 
this equipment leak control option would result in an emission 
reduction of around 130 tons per year. The risk reduction would still 
be minimal. The cost would not differ, although the cost effectiveness 
would be somewhat lower at over $6,000 per ton when based on MACT 
allowable emissions. As a result, we propose that, based on actual and 
MACT allowable emissions, the existing MACT standard provides an ample 
margin of safety (considering cost, technical feasibility, and other 
factors) to protect public health.
    We are also required to consider the potential for adverse impacts 
to the environment as part of a residual risk assessment. As previously 
noted, we believe that human toxicity values for the inhalation pathway 
are generally protective of terrestrial mammals. Because the maximum 
cancer and noncancer hazards to humans from inhalation exposure are 
relatively low, we expect there to be no potential for significant and 
widespread adverse effect to terrestrial mammals from inhalation 
exposure to HAP emitted from the Pharmaceuticals Production source 
category. To evaluate the potential for adverse effect to other 
wildlife, we carried out a screening-level assessment of adverse

[[Page 60456]]

environmental effects via exposure to PB-HAP emissions. This source 
category reported PB-HAP emissions, but, based on our application of 
the screening scenario developed for TRIM.FaTE model, no potential for 
an adverse environment effect via multipathway exposures was 
identified. Since our results showed no potential for an adverse 
environmental effect, we also do not believe there is any potential for 
an adverse effect on threatened or endangered species or on their 
critical habitat within the meaning of 50 CFR 402.14(a). With these 
results, we have concluded that a consultation with the Fish and 
Wildlife Service is not necessary.
    In summary, we propose that the current MACT standard provides an 
ample margin of safety to protect public health. The additional control 
available is not cost-effective in light of the additional health 
protection against maximum individual cancer risk and chronic and acute 
noncancer hazard the control would provide. In addition, we believe 
that there is no potential for adverse environmental effect. Thus, we 
are proposing to re-adopt the existing MACT standard to satisfy section 
112(f) of the CAA.
9. Printing and Publishing Industry
    The Printing and Publishing source category emits HAP which are 
known, probable, or possible carcinogens. EPA evaluated the emissions 
of these HAP and determined that they pose maximum individual cancer 
risks less than 1-in-1 million to the individual most exposed. Because 
these risks are less than 1-in-1 million, EPA is not required to 
promulgate standards under 112(f)(2) for the Printing and Publishing 
source category unless promulgation of standards is required to prevent 
an adverse environmental effect. Accordingly, EPA undertook further 
analysis to assess whether environmental effects might result from 
emissions from this source category.
    Our analysis demonstrated that chronic noncancer risks are expected 
to be low, based on actual and MACT allowable emissions. We determined 
that emissions from the Printing and Publishing category would result 
in chronic noncancer target organ-specific HI less than or equal to 1 
for the individual most exposed. Thus we do not anticipate that actual 
or MACT allowable emissions would result in adverse chronic noncancer 
health effects.
    While the refined assessment for acute impacts suggests that short-
term toluene concentrations at six modeled facilities could exceed 
acute thresholds, we believe it unlikely that acute impacts would 
occur. Acute impacts of policy significance are unlikely because we 
based the refined assessment on worst-case meteorological conditions 
(estimated to occur up to 2 percent of the time) being present at the 
same time that maximum hourly emissions of toluene exceed the average 
hourly emission rate by a factor of 10, coincident with individuals 
being in the location of maximum impact. This set of assumptions 
results in an estimate of a 10-fold exceedance of the toluene REL. As 
noted in the acute REL documentation, ``RELs are based on the most 
sensitive, relevant, adverse health effect reported in the medical and 
toxicological literature. RELs are designed to protect the most 
sensitive individuals in the population by the inclusion of margins of 
safety. Since margins of safety are incorporated to address data gaps 
and uncertainties, exceeding the REL does not automatically indicate an 
adverse health impact.''
    We are also required to consider the potential for adverse impacts 
to the environment as part of a residual risk assessment. As previously 
noted, we believe that human toxicity values for the inhalation pathway 
are generally protective of terrestrial mammals. Because the maximum 
cancer and noncancer hazards to humans from inhalation exposure are 
low, we expect there to be no potential for significant and widespread 
adverse effect to terrestrial mammals from inhalation exposure to HAP 
emitted from the Printing and Publishing Industry source category. To 
evaluate the potential for adverse effect to other wildlife, we carried 
out a screening-level assessment of adverse environmental effects via 
exposure to PB-HAP emissions. This source category reported PB-HAP 
emissions, but, based on our application of the screening scenario 
developed for TRIM.FaTE model, no potential for an adverse environment 
effect via multipathway exposures was identified. Because our results 
showed no potential for an adverse environmental effect, we also do not 
believe there is any potential for an adverse effect on threatened or 
endangered species or on their critical habitat within the meaning of 
50 CFR 402.14(a). With these results, we have concluded that a 
consultation with the Fish and Wildlife Service is not necessary.
    In summary, we propose that the current MACT standard provides an 
ample margin of safety to protect public health because the maximum 
individual cancer risk is below 1-in-1 million, the chronic noncancer 
risks are low, and the acute noncancer hazards are below a level of 
concern. In addition, we believe that there is no potential for adverse 
environmental effect. In reaching this conclusion, we did not consider 
costs. Thus, we are proposing to re-adopt the existing MACT standard to 
satisfy section 112(f) of the CAA.

G. What are the results of the technology review?

    Section 112(d)(6) of the CAA requires us to review and revise MACT 
standards, as necessary, every 8 years, taking into account 
developments in practices, processes, and control technologies that 
have occurred during that time. This authority provides us with broad 
discretion to revise the MACT standards as we determine necessary, and 
to account for a wide range of relevant factors. We interpret CAA 
section 112(d)(6) as requiring us to consider developments in pollution 
control in the industry ``taking into account developments in 
practices, processes, and control technologies,'' and to assess the 
costs of potentially stricter standards reflecting those developments 
(69 FR 48351). We consider ``developments in practices, processes, and 
control technologies'' to be:
     Any add-on control technology or other equipment (e.g., 
floating roofs for storage tanks) that was not identified and 
considered during MACT development for the source category,
     Any improvements in add-on control technology or other 
equipment (that was identified and considered during MACT development 
for the source category) that could result in significant additional 
emission reduction,
     Any work practice or operational procedure that was not 
identified and considered during MACT development for the source 
category, and
     Any process change or pollution prevention alternative 
that could be broadly applied that was not identified and considered 
during MACT development for the source category.
    For the source categories in RTR Group 2A, our review of 
developments in practices, processes, and control technologies has been 
on-going since promulgation of the five NESHAP. In the years since the 
RTR Group 2A NESHAP were promulgated, EPA has developed air toxics 
regulations for a number of source categories that emit HAP from the 
same type of emission sources and have evaluated practices, processes, 
and control techniques for each rulemaking. Thus, the first source of 
information about practices, processes, and control technologies is

[[Page 60457]]

our own data and experience with the various industry sectors and 
source categories.
    The second source of information is EPA's RACT/BACT/LAER 
clearinghouse. The RACT/BACT/LAER clearinghouse is an EPA-maintained 
central data base of case-specific information on the ``Best 
Available'' air pollution technologies that have been required to 
reduce the emissions of air pollutants from stationary sources (e.g., 
power plants, steel mills, chemical plants, etc.). The third source of 
information is information received directly from the industry 
regarding any developments in practices, processes, or controls.
    The sections below provide more discussion about the technology 
review analyses and results for each of the nine source categories. 
More detail about the technology review can be found in the technology 
review documents written for each source category. The technology 
review documents are in the RTR Group 2A docket.
1. Polymers and Resins I
    In the decade since the Polymers and Resins I NESHAP was 
promulgated, EPA has developed 18 air toxics regulations for source 
categories that emit organic HAP from the same type of emission sources 
that are present in the five Polymers and Resins source categories in 
RTR Group 2A. We reviewed the regulatory requirements and/or technical 
analyses for these 18 regulations for new practices, processes, and 
control techniques. We also conducted a search of the BACT/RACT/LAER 
clearinghouse for controls for VOC- and HAP-emitting processes in the 
Polymers and Resins and the Synthetic Organic Chemical Manufacturing 
Industry (SOCMI) categories with permits dating back to 1997. In 
addition to these two sources of information, we obtained information 
directly from the industry regarding any developments in practices, 
processes, or controls.
    We identified no advancements in practices, processes, and control 
technologies applicable to the emission sources in the Polymers and 
Resins I source categories in our technology review.
2. Marine Vessel Loading Operations
    In the decade since the Marine Vessel Loading NESHAP was 
promulgated, EPA has developed eight air toxics regulations for source 
categories that emit organic HAP from the same type of emission sources 
that are present in the marine vessel loading source category. We 
reviewed the regulatory requirements and/or technical analyses for 
these eight regulations for new practices, processes, and control 
techniques. We also conducted a search of the BACT/RACT/LAER 
clearinghouse for controls for VOC- and HAP-emitting loading processes 
in the Organic Liquid Storage and Marketing categories with permits 
dating back to 1997. In addition to these two sources of information, 
we also obtained information from industries with similar emissions 
sources with potentially transferable controls to determine if they 
have any developments in practices, processes, or controls that could 
be applied here.
    We identified no advancements in practices, processes, and control 
technologies applicable to the emission sources in the Marine Vessel 
Loading source category in our technology review.
3. Mineral Wool Production
    Since the Mineral Wool NESHAP was promulgated, EPA has developed 
several air toxics regulations for source categories that emit organic 
HAP from similar types of emission sources that are present in the 
mineral wool source category. These similar types of emissions sources 
include both melting furnaces and curing ovens. We reviewed the 
regulatory requirements and/or technical analyses associated with each 
of the subsequent regulatory actions to identify any practices, 
processes, and control techniques considered in these efforts that 
could possibly be applied to the Mineral Wool Production source 
category. In addition to the review of subsequent regulatory actions 
for similar emissions types such as melting furnaces and curing ovens, 
EPA conducted a review for other VOC- and organic HAP-emitting 
processes that have similar technology-transferable controls.
    We also conducted a search of the BACT/RACT/LAER clearinghouse for 
the Mineral Wool Production source category and found the following 
processes, practices, and control technologies: wet scrubbers for 
particulate matter (PM); baghouse dust collectors for PM; electrostatic 
precipitators for PM; and thermal oxidizer for VOC. These practices, 
processes, and control technologies are all examples of the types of 
emission reduction techniques that were considered in the development 
of the Mineral Wool MACT standard. In addition to the search for 
similar processes such as cupolas, melting ovens or furnaces, and 
curing ovens, we conducted a search for other PM, HAP metals, VOC, and 
organic HAP processes that have similar, technology-transferable 
controls. No developments in practices, processes, or control 
technologies were revealed as a result of that search.
    In addition to these two sources of information, we also obtained 
information from industries with technology transferable controls 
regarding developments in practices, processes, or controls.
    We identified no advancements in practices, processes, and control 
technologies applicable to the emission sources in the Mineral Wool 
Production source category in our technology review.
4. Pharmaceuticals Production
    In the decade since the Pharmaceutical NESHAP was promulgated, EPA 
has developed 10 air toxics regulations for source categories that emit 
organic HAP from the same type of emission sources that are present in 
the pharmaceutical source category. We reviewed the regulatory 
requirements and/or technical analyses for these 10 regulations for new 
practices, processes, and control techniques. We also conducted a 
search of the BACT/RACT/LAER clearinghouse for controls for VOC- and 
HAP-emitting processes in the Pharmaceuticals source category.
    We identified no advancements in practices, processes, and control 
technologies applicable to the emission sources in the Pharmaceuticals 
Production source categories in our technology review.
5. Printing and Publishing Industry
    In the twelve years since the Printing and Publishing NESHAP was 
promulgated, EPA has developed three air toxics regulations that emit 
organic HAP from emission sources that are similar to those addressed 
in the Printing and Publishing NESHAP. We reviewed the regulatory 
requirements and/or technical analyses associated with each of three 
subsequent regulatory actions to identify any practices, processes, and 
control techniques considered in these efforts that could possibly be 
applied to the Printing and Publishing Industry source category. We 
also conducted a search of the BACT/RACT/LAER clearinghouse for permits 
dating back to 1990 for controls for VOC- and HAP-emitting processes in 
the Printing and Publishing Industry and four additional source 
categories with emission sources similar to those in the Printing and 
Publishing Industry source category.
    In addition to these two sources of information, we obtained 
information directly from the printing and

[[Page 60458]]

publishing industry and the closely related paper, film, and foil 
coating industry regarding developments in practices, processes, or 
controls.
    We identified no advancements in practices, processes, and control 
technologies applicable to the emission sources in the Printing and 
Publishing source category in our technology review.

II. Proposed Action

    We propose that each of the five MACT standards for the nine source 
categories evaluated in RTR Group 2A--Epichlorohydrin Elastomers 
Production, HypalonTM Production, Nitrile Butadiene Rubber Production, 
Polybutadiene Rubber Production, and Styrene Butadiene Rubber and Latex 
Production, Marine Vessel Loading Operations, Mineral Wool Production, 
Pharmaceuticals Production, and the Printing and Publishing Industry--
provide an ample margin of safety to protect public health and adverse 
environmental effect. Thus, we are proposing to re-adopt each of these 
standards for purposes of meeting the requirements of CAA section 
112(f)(2). In addition, we propose that there are no developments in 
practices, processes, or control technologies that support revision of 
the five MACT standards pursuant to CAA section 112(d)(6).

A. What is the rationale for our proposed action under CAA Section 
112(f)?

    Section 112(f) of the CAA requires that EPA promulgate standards 
for a category if promulgation of such standards is required to provide 
an ample margin of safety to protect public health or to prevent, 
taking into consideration costs, energy, safety, and other relevant 
factors, an adverse environmental effect. The approach we use to make 
this determination is that set forth in the preamble to the Benzene 
NESHAP. First, we exclusively evaluate health risk measures and 
information in determining whether risks are acceptable. Second, we may 
consider costs and other factors in deciding whether further emission 
reductions are necessary to provide an ample margin of safety to 
protect public health. The EPA is not required to promulgate standards 
for a source category under CAA section 112(f) if the emissions 
standards protect public health with an ample margin of safety and 
prevent an adverse environmental effect.
    We determined for the printing and publishing industry that the 
maximum individual cancer risks were less than 1-in-1 million to the 
individual most exposed, and that emissions were unlikely to cause 
other adverse human health or environmental effects. For the other 
eight source categories addressed in this proposal, Epichlorohydrin 
Elastomers Production, Hypalon \TM\ Production, Nitrile Butadiene 
Rubber Production, Polybutadiene Rubber Production, Styrene-Butadiene 
Rubber and Latex Production, Marine Vessel Loading Operations, Mineral 
Wool Production, and Pharmaceuticals Production, we determined that 
maximum individual cancer risks were between 1-in-1 million and 100-in-
1 million to the individual most exposed. Because the risks to the 
individual most exposed are greater than 1-in-1 million for these 
source categories, we considered whether the existing NESAHP provides 
an ample margin of safety to protect public. In doing so, we took into 
account chronic non-cancer risks, acute risks, and environmental risks. 
For each of these eight source categories, we evaluated one or more 
control options and considered the cost of such controls, the emission 
reductions that would achieve and the impacts of those options on 
public health. We determined that the existing NESHAP for each source 
category provides an ample margin of safety to protect public health 
and prevents adverse environmental effects. Therefore, we determined 
that changes to the NESHAP are not required to satisfy section 112(f) 
of the CAA. This finding considers the additional costs of further 
control compared with the relatively small reductions in health risks 
achieved by the options for further control for each source category.

B. What is the rationale for our proposed action under CAA Section 
112(d)(6)?

    As explained in section I.F. of this preamble, there have been no 
significant developments in practices, processes, or control 
technologies since promulgation of the NESHAP. Because there have been 
no such significant developments and because existing standards provide 
an ample margin of safety to protect public health, we conclude that no 
further revisions to the standards affected by this proposal are needed 
under section 112(d)(6) of the CAA.

III. Request for Comments

    We request comment on all aspects of the proposed action. All 
significant comments received during the comment period will be 
considered. In addition to general comments on the proposed actions, we 
are also interested in additional data to reduce the uncertainties of 
the risk assessments. Comments must provide supporting documentation in 
sufficient detail to allow characterization of the quality and 
representativeness of the data or information.
    The facility-specific data for each source category are available 
for download on the RTR Web page at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. The nine source categories affected by this proposal are 
referred to as Group 2A of RTR Phase 2. These data files include 
detailed information for each emissions release point at each facility 
in the source category. For large integrated facilities with multiple 
processes representing multiple source categories, it is often 
difficult to clearly distinguish the source category to which each 
emission point belongs. For this reason, the data available for 
download for each source category include all emission points for each 
facility in the source category, though only the emission points marked 
as belonging to the specific source category in question were included 
in the analysis for that source category.
    The data files for each source category must be downloaded from the 
RTR Web page to be viewed (http://www.epa.gov/ttn/atw/rrisk/rtrpg.html). These are Microsoft[supreg] Access files, which require 
Microsoft[supreg] Access to be viewed (if you do not have 
Microsoft[supreg] Access, contact us by e-mail at [email protected]). Each 
file contains the following information from the NEI for each facility 
in the source category:

------------------------------------------------------------------------
             Facility data                        Emissions data
------------------------------------------------------------------------
EPA Region.............................  Pollutant Code.
Tribal Code............................  Pollutant Code Description.
Tribe Name.............................  HAP Category Name.
State Abbreviation.....................  Emissions (TPY).
                                         Control Measure in Place (Y/N).
County Name............................  MACT Code.
State County FIPS......................  MACT Source Category Name.

[[Page 60459]]

 
NEI Site ID............................  MACT Flag.
Facility Name..........................  MACT Compliance Status Code.
Location Address.......................  SCC Code.
City Name..............................  SCC Code Description.
State Name.............................  Emission Unit ID.
Zip Code...............................  Process ID.
Facility Registry Identifier...........  Emission Release Point ID.
State Facility Identifier..............  Emission Release Point Type
                                          Code.
SIC Code...............................  Emission Release Point Type.
SIC Code Description...................  Stack Default Flag.
NAICS Code.............................  Stack Default Flag Description.
Facility Category Code.................  Stack height.
Facility Category......................  Exit Gas Temperature.
                                         Stack Diameter.
                                         Exit Gas Velocity.
                                         Exit Gas Flow Rate.
                                         Fugitive Length.
                                         Fugitive Width.
                                         Fugitive Angle.
                                         Longitude.
                                         Latitude.
                                         Location Default Flag.
                                         Data Source Code.
                                         Data Source Description.
                                         HAP Emissions Performance Level
                                          Code.
                                         HAP Emissions Performance Level
                                          Description.
                                         Start Date.
                                         End Date.
------------------------------------------------------------------------

    More information on these NEI data fields can be found in the NEI 
documentation at http://www.epa.gov/ttn/chief/net/2002inventory.html#documentation.

IV. How do I submit suggested data corrections?

    If you believe that the data are not representative or are 
inaccurate, please identify the data in question, provide your reason 
for concern, and provide improved data, if available. When submitting 
data, we ask that you provide documentation of the basis for the 
revised values to support any suggested changes.
    To submit comments on the data downloaded from the RTR Web page, 
complete the following steps:
    1. Within this downloaded file, enter suggested revisions in the 
data fields appropriate for that information. The data fields that may 
be revised include the following:

------------------------------------------------------------------------
             Facility data                        Emissions data
------------------------------------------------------------------------
REVISED Tribal Code....................  REVISED Emissions (TPY).
REVISED County Name....................  Emissions Calculation Method
                                          Code.
REVISED Facility Name..................  REVISED MACT Code.
REVISED Location Address...............  REVISED SCC Code.
REVISED City Name......................  REVISED Emission Release Point
                                          Type.
REVISED State Name.....................  REVISED Start Date.
REVISED Zip Code.......................  REVISED End Date.
REVISED Facility Registry Identifier...  REVISED Pollutant Code.
                                         REVISED Control Measure in
                                          Place (Y/N).
                                         Control Measure.
REVISED Facility Category Code.........  REVISED Stack height.
                                         REVISED Exit Gas Temperature.
                                         REVISED Stack Diameter.
                                         REVISED Exit Gas Velocity.
                                         REVISED Exit Gas Flow Rate.
                                         REVISED Longitude.
                                         REVISED Latitude.
                                         North American Datum.
                                         REVISED HAP Emissions
                                          Performance Level.
------------------------------------------------------------------------

    2. Fill in the following commenter information fields for each 
suggested revision:
     Commenter Name
     Commenter Organization
     Commenter E-Mail Address
     Commenter Phone Number
     Revision Comments
    3. Gather documentation for any suggested emissions revisions 
(e.g., performance test reports, material balance calculations, etc.).
    4. Send the entire downloaded file with suggested revisions in 
Microsoft[reg] Access format and all accompanying documentation to 
Docket ID No. EPA-HQ-OAR-2008-0008 (through one of the methods 
described in the ADDRESSES section of this preamble). To answer 
questions on navigating through the

[[Page 60460]]

data and to help expedite review of the revisions, it would also be 
helpful to submit revisions to EPA directly at [email protected] in addition 
to submitting them to the docket.
    5. If you are providing comments on a facility with multiple source 
categories, you need only submit one file for that facility, which 
should contain all suggested changes for all source categories at that 
facility.
    We strongly urge that all data revision comments be submitted in 
the form of updated Microsoft[reg] Access files, which are provided on 
the http://www.epa.gov/ttn/atw/rrisk/rtrpg.html Web page. Data in the 
form of written descriptions or other electronic file formats will be 
difficult for EPA to translate into the necessary format in a timely 
manner.

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is a significant regulatory action. This action is a significant 
regulatory action because it raises novel legal and policy issues. 
Accordingly, EPA submitted this action to the Office of Management and 
Budget (OMB) for review under Executive Order 12866 and any changes 
made in response to OMB recommendations have been documented in the 
docket for this action.

B. Paperwork Reduction Act

    This action does not impose any new information collection burden. 
This action is proposing no changes to the existing regulations 
affecting the nine source categories affected by this proposal and will 
impose no additional information collection burden.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impact of this rule on small 
entities, small entity is defined as: (1) A small business as defined 
by the Small Business Administration's regulations at 13 CFR 121.201; 
(2) a small governmental jurisdiction that is a government of a city, 
county, town, school district, or special district with a population of 
less than 50,000; and (3) a small organization that is any not-for-
profit enterprise which is independently owned and operated and is not 
dominant in its field.
    After considering the economic impact of this rule on small 
entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. This 
proposed rule will not impose any requirements on small entities. EPA 
is proposing no further action at this time to revise the NESHAP.
    We continue to be interested in the potential impacts of the 
proposed rule on small entities and welcome comments on issues related 
to such impacts.

D. Unfunded Mandates Reform Act

    This proposed rule contains no Federal mandates under the 
provisions of Title II of the Unfunded Mandates Reform Act (UMRA), 2 
U.S.C. 1531-1538 for State, local, or tribal governments or the private 
sector. The rule imposes no enforceable duty on State, local, or tribal 
governments, or the private sector. Therefore, this proposed rule is 
not subject to the requirements of sections 202 or 205 of the UMRA.
    This proposed rule is also not subject to the requirements of 
section 203 of the UMRA because it contains no regulatory requirements 
that might significantly or uniquely affect small governments because 
it contains no requirements that apply to such governments nor does it 
impose obligations upon them.

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled Federalism (64 FR 43255, August 10, 
1999), requires EPA to develop an accountable process to ensure 
meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications. 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that 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.
    This proposed rule 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, 
as specified in Executive Order 13132. None of the facilities in the 
RTR Group 1 source categories are owned or operated by State 
governments, and, because no new requirements are being promulgated, 
nothing in this proposal will supersede State regulations. Thus, 
Executive Order 13132 does not apply to this proposed rule.
    In the spirit of Executive Order 13132, and consistent with EPA 
policy to promote communications between EPA and State and local 
governments, EPA specifically solicits comment on this proposed rule 
from State and local officials.

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

    This proposed rule does not have tribal implications, as specified 
in Executive Order 13175 (65 FR 67249, November 9, 2000). It will not 
have substantial direct effect 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 rule.
    EPA specifically solicits additional comment on this proposed rule 
from tribal officials.

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

    The proposed rule is not subject to Executive Order 13045 (62 FR 
19885, April 23, 1997) because it is not economically significant as 
defined in Executive Order 12866, and because the Agency 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 section I.D., E., and F. 
of this preamble.

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

    This proposed rule is not a ``significant energy action'' as 
defined in Executive Order 13211, (66 FR 28355, May 22, 2001) because 
it is not likely to have a significant adverse effect on the supply, 
distribution, or use of energy. It does not impose any new energy 
requirements. Further, we have concluded that this rule will not have 
any adverse energy effects.

[[Page 60461]]

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, 12(d) (15 U.S.C. 272 note) 
directs EPA to use voluntary consensus standards (VCS) in its 
regulatory activities, unless to do so would be inconsistent with 
applicable law or otherwise impractical. VCS are technical standards 
(e.g., materials specifications, test methods, sampling procedures, and 
business practices) that are developed or adopted by VCS bodies. NTTAA 
directs EPA to provide Congress, through OMB, explanations when the 
Agency decides not to use available and applicable VCS.
    The proposed rulemaking does not involve technical standards. 
Therefore, EPA is not considering the use of any VCS.

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

    Executive Order 12898 (59 FR 7629, February 16, 1994) establishes 
Federal executive policy on environmental justice. Its main provision 
directs Federal agencies, to the greatest extent practicable and 
permitted by law, to make environmental justice part of their mission 
by identifying and addressing, as appropriate, disproportionately high 
and adverse human health or environmental effects of their programs, 
policies, and activities on minority populations and low-income 
populations in the United States.
    EPA has determined that this proposed rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it does not 
affect the level of protection provided to human health or the 
environment. This proposed rule would not relax the control measures on 
sources regulated by the rule and, therefore, would not cause emissions 
increases from these sources.

List of Subjects in 40 CFR Part 63

    Environmental protection, Administrative practice and procedures, 
Air pollution control, Hazardous substances, Intergovernmental 
relations, Reporting and recordkeeping requirements.

    Dated: September 29, 2008.
Stephen L. Johnson,
Administrator.
 [FR Doc. E8-23373 Filed 10-9-08; 8:45 am]
BILLING CODE 6560-50-P