Document ID: EPA-HQ-OAR-2011-0435-0001
Agency: epa
Document Type: Proposed Rule
Title: National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins; Pesticide Active Ingredient Production; and Polyether Polyols Production
Posted Date: 2012-01-09T05:00Z

[Federal Register Volume 77, Number 5 (Monday, January 9, 2012)]
[Proposed Rules]
[Pages 1268-1318]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-32934]

[[Page 1267]]

Vol. 77

Monday,

No. 5

January 9, 2012

Part IV

Environmental Protection Agency

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40 CFR Part 63

National Emission Standards for Hazardous Air Pollutant Emissions: 
Group IV Polymers and Resins; Pesticide Active Ingredient Production; 
and Polyether Polyols Production; Proposed Rule

  Federal Register / Vol. 77 , No. 5 / Monday, January 9, 2012 / 
Proposed Rules  

[[Page 1268]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2011-0435; FRL-9507-8]
RIN 2060-AR02

National Emission Standards for Hazardous Air Pollutant 
Emissions: Group IV Polymers and Resins; Pesticide Active Ingredient 
Production; and Polyether Polyols Production

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The EPA is proposing amendments to three national emission 
standards for hazardous air pollutants (NESHAP): National Emission 
Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and 
Resins; NESHAP for Pesticide Active Ingredient Production; and NESHAP 
for Polyether Polyols Production. For all three of these NESHAP rules, 
the EPA is proposing decisions concerning the following: residual risk 
reviews; technology reviews; emissions during periods of startup, 
shutdown and malfunction; standards for previously unregulated 
hazardous air pollutant emissions; and electronic reporting of 
performance test results.

DATES: Comments. Comments must be received on or before March 9, 2012. 
Under the Paperwork Reduction Act, comments on the information 
collection provisions are best assured of having full effect if the 
Office of Management and Budget (OMB) receives a copy of your comments 
on or before February 8, 2012.
    Public Hearing. If anyone contacts the EPA requesting to speak at a 
public hearing by January 19, 2012, a public hearing will be held on 
February 8, 2012.

ADDRESSES: Comments. Submit your comments, identified by Docket ID No. 
EPA-HQ-OAR-2011-0435, by one of the following methods:
     www.regulations.gov: Follow the on-line instructions for 
submitting comments.
     Email: a-and-r-docket@epa.gov. Attention Docket ID No. 
EPA-HQ-OAR-2011-0435.
     Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2011-0435.
     Mail: U.S. Postal Service, send comments to: EPA Docket 
Center, EPA West (Air Docket), Attention Docket ID No. EPA-HQ-OAR-2011-
0435, U.S. Environmental Protection Agency, Mailcode: 2822T, 1200 
Pennsylvania Ave. NW., Washington, DC 20460. Please include a total of 
two copies. In addition, please mail a copy of your comments on the 
information collection provisions to the Office of Information and 
Regulatory Affairs, Office of Management and Budget (OMB), Attn: Desk 
Officer for EPA, 725 17th Street NW., Washington, DC 20503.
     Hand Delivery: U.S. Environmental Protection Agency, EPA 
West (Air Docket), Room 3334, 1301 Constitution Ave. NW., Washington, 
DC 20004. Attention Docket ID No. EPA-HQ-OAR-2011-0435. Such deliveries 
are only accepted during the Docket's normal hours of operation, and 
special arrangements should be made for deliveries of boxed 
information.
    Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2011-0435. The 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 email. The http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means the EPA will not know 
your identity or contact information unless you provide it in the body 
of your comment. If you send an email comment directly to the EPA 
without going through http://www.regulations.gov, your email 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, the 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 the EPA cannot read your comment 
due to technical difficulties and cannot contact you for clarification, 
the 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 the 
EPA's public docket, visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket. The EPA has established a docket for this rulemaking under 
Docket ID No. EPA-HQ-OAR-2011-0435. 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, is not placed on the Internet 
and 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, EPA West, 
Room 3334, 1301 Constitution Ave. 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.
    Public Hearing. If a public hearing is held, it will begin at 10 
a.m. on February 8, 2012 and will be held at the 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, Sector Policies and Programs Division (E143-01), Office of Air 
Quality Planning and Standards, U.S. Environmental Protection Agency, 
Research Triangle Park, NC 27711, telephone number: (919) 541-4516. If 
a public hearing will be held, a notification will be posted on the 
following Web site: http://www.epa.gov/ttn/oarpg/t3main.html.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Mr. Nick Parsons, Sector Policies and Programs Division 
(E143-01), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711; 
telephone number: (919) 541-5372; fax number: (919) 541-0246; email 
address: parsons.nick@epa.gov. For specific information regarding the 
risk modeling methodology, contact Ms. Elaine Manning, Health and 
Environmental Impacts Division (C159-02), Office of Air Quality 
Planning and Standards, U.S. Environmental Protection Agency, Research 
Triangle Park, NC 27711; telephone number: (919) 541-5499; fax number: 
(919) 541-0840; email address: manning.elaine@epa.gov. For information 
about the applicability of these three national emission standards for 
hazardous air pollutants (NESHAP) to a particular entity, contact the 
appropriate person listed in Table 1 to this preamble.

[[Page 1269]]

    Table 1--List of the EPA Contacts for the Rules Addressed in This
                             Proposed Action
------------------------------------------------------------------------
           NESHAP               OECA contact \1\      OAQPS contact \2\
------------------------------------------------------------------------
NESHAP for Group IV Polymers  Tavara Culpepper,     Nick Parsons, (919)
 and Resins.                   (202) 564-0902,       541-5372,
                               culpepper.tavara@ep   parsons.nick@epa.go
                               a.gov.                v.
NESHAP for Pesticide Active   Tavara Culpepper,     Andrea Siefers,
 Ingredient Production.        (202) 564-0902,       (919) 541-1185,
                               culpepper.tavara@ep   siefers.andrea@epa.
                               a.gov.                gov.
NESHAP for Polyether Polyols  Tavara Culpepper,     Andrea Siefers,
                               (202) 564-0902,       (919) 541-1185,
                               culpepper.tavara@ep   siefers.andrea@epa.
                               a.gov.                gov.
------------------------------------------------------------------------
\1\ OECA stands for the EPA's Office of Enforcement and Compliance
  Assurance.
\2\ OAQPS stands for the EPA's Office of Air Quality Planning and
  Standards.

SUPPLEMENTARY INFORMATION:

Preamble Acronyms and Abbreviations

    Several acronyms and terms used to describe industrial processes, 
data inventories and risk modeling are included in this preamble. While 
this may not be an exhaustive list, to ease the reading of this 
preamble and for reference purposes, the following terms and acronyms 
are defined here:

ABS--Acrylonitrile Butadiene Styrene Resin
ADAF--Age-Dependent Adjustment Factors
AERMOD--Air Dispersion Model used by the HEM-3 Model
AEGL--Acute Exposure Guideline Levels
ASA/AMSAN--Acrylonitrile Styrene Resin/Alpha Methyl Styrene 
Acrylonitrile Resin
BACT--Best Available Control Technology
CalEPA--California Environmental Protection Agency
CAA--Clean Air Act
CBI--Confidential Business Information
CDX--Central Data Exchange
CEDRI--Compliance and Emissions Data Reporting Interface
CFR--Code of Federal Regulations
EPA--Environmental Protection Agency
ERPG--Emergency Response Planning Guidelines
ERT--Electronic Reporting Tool
HAP--Hazardous Air Pollutants
HCl--Hydrochloric Acid
HI--Hazard Index
HEM-3--Human Exposure Model, Version 3
HON--National Emission Standards for Organic Hazardous Air 
Pollutants From the Synthetic Organic Chemical Manufacturing 
Industry
HQ--Hazard Quotient
ICR--Information Collection Request
IRIS--Integrated Risk Information System
km--Kilometer
LAER--Lowest Achievable Emission Rate
LDAR--Leak Detection and Repair
MACT--Maximum Achievable Control Technology
MACT Code--Code within the NEI used to Identify Processes Included 
in a Source Category
MBS--Methyl Methacrylate Butadiene Styrene
MIR--Maximum Individual Risk
NAAQS--National Ambient Air Quality Standards
NAICS--North American Industry Classification System
NAS--National Academy of Sciences
NATA--National Air Toxics Assessment
NESHAP--National Emissions Standards for Hazardous Air Pollutants
NEI--National Emissions Inventory
NRC--National Research Council
NTTAA--National Technology Transfer and Advancement Act
OECA--Office of Enforcement and Compliance Assurance
OMB--Office of Management and Budget
P&R IV--National Emission Standards for Hazardous Air Pollutant 
Emissions: Group IV Polymers and Resins
PAI--Pesticide Active Ingredient
PB-HAP--Hazardous Air Pollutants known to be Persistent and Bio-
Accumulative in the Environment
PCB--Polychlorinated Biphenyls
PCCT--Process Contact Cooling Tower
PEPO--Polyether Polyols
PET--Poly (Ethylene Terephthalate) Resin
PM--Particulate Matter
POM--Polycyclic Organic Matter
PRD--Pressure Relief Device
RACT--Reasonably Available Control Technology
RBLC--RACT/BACT/LAER Clearinghouse
REL--CalEPA Chronic Reference Exposure Level
RFA--Regulatory Flexibility Act
RfC--Reference Concentration
RfD--Reference Dose
RTR--Residual Risk and Technology Review
SAB--Science Advisory Board
SAN--Styrene Acrylonitrile Resin
SCC--Source Classification Codes
SOCMI--Synthetic Organic Chemical Manufacturing Industry
SOP--Standard Operating Procedures
SSM--Startup, Shutdown and Malfunction
THF--Tetrahydrofuran
TOSHI--Target Organ-Specific Hazard Index
TPA--Terephthalic Acid
tpy--Tons Per Year
TRIM--Total Risk Integrated Modeling System
TRIM.FaTE--EPA's Total Risk Integrated Methodology Fate, Transport 
and Ecological Exposure Model
TTN--Technology Transfer Network
UF--Uncertainty Factor
UMRA--Unfunded Mandates Reform Act
URE--Unit Risk Estimate
VOC--Volatile Organic Compounds
WWW--World Wide Web

    Organization of this Document. The information in this preamble is 
organized as follows:

I. General Information
    A. What is the statutory authority for this action?
    B. Does this action apply to me?
    C. Where can I get a copy of this document and other related 
information?
    D. What should I consider as I prepare my comments for the EPA?
II. Background
    A. What are the source categories addressed by this action?
    B. What data collection activities were conducted to support 
this proposed action?
III. Analyses Performed
    A. How did we address unregulated emissions sources?
    B. How did we estimate risks posed by the source categories?
    C. How did we consider the risk results in making decisions for 
this proposal?
    D. How did we perform the technology review?
    E. What other issues are we addressing in this proposal?
IV. Analytical Results and Proposed Decisions for the Group IV 
Polymers and Resins Source Categories
    A. Acrylonitrile Butadiene Styrene Resin (ABS)
    B. Styrene Acrylonitrile Resin (SAN)
    C. Methyl Methacrylate Butadiene Styrene Resin (MBS)
    D. Polystyrene Resin
    E. Poly (ethylene terephthalate) Resin (PET)
V. Analytical Results and Proposed Decisions for Pesticide Active 
Ingredient Production
    A. What are the results of the risk assessments?
    B. What are the results of the technology review?
    C. What other actions are we proposing?
VI. Analytical Results and Proposed Decisions for Polyether Polyols 
Production
    A. What are the results of the risk assessments?
    B. What are the results of the technology review?
    C. What other actions are we proposing?
VII. Compliance Dates
VIII. Summary of Cost, Environmental and Economic Impacts
    A. What are the affected sources?
    B. What are the air quality impacts?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
IX. Request for Comments
X. Submitting Data Corrections
XI. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive

[[Page 1270]]

Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health 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

A red-line version of the regulatory language that incorporates the 
proposed changes in this action is available in the docket.

I. General Information

A. What is the statutory authority for this action?

    Section 112 of the Clean Air Act (CAA) establishes a two-stage 
regulatory process to address emissions of hazardous air pollutants 
(HAP) from stationary sources. In the first stage, after the EPA has 
identified categories of sources emitting one or more of the HAP listed 
in CAA section 112(b), CAA section 112(d) calls for us to promulgate 
technology-based NESHAP for those sources. ``Major sources'' are those 
that emit or have the potential to emit 10 tons per year (tpy) or more 
of a single HAP or 25 tpy or more of any combination of HAP. For major 
sources, these technology-based standards must reflect the maximum 
degree of emissions 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.
    MACT standards must require the maximum degree of emissions 
reduction achievable through the application of measures, processes, 
methods, systems or techniques, including, but not limited to, measures 
that: (1) Reduce the volume of or eliminate pollutants through process 
changes, substitution of materials or other modifications; (2) enclose 
systems or processes to eliminate emissions; (3) capture or treat 
pollutants when released from a process, stack, storage or fugitive 
emissions point; (4) are design, equipment, work practice or 
operational standards (including requirements for operator training or 
certification); or (5) are a combination of the above. CAA section 
112(d)(2)(A)-(E). The MACT standards may take the form of design, 
equipment, work practice or operational standards where the EPA first 
determines either that: (1) A pollutant cannot be emitted through a 
conveyance designed and constructed to emit or capture the pollutants 
or that any requirement for, or use of, such a conveyance would be 
inconsistent with law; or (2) the application of measurement 
methodology to a particular class of sources is not practicable due to 
technological and economic limitations. CAA sections 112(h)(1)-(2).
    The MACT ``floor'' is the minimum control level allowed for MACT 
standards promulgated under CAA section 112(d)(3) and may not be based 
on cost considerations. For new sources, the MACT floor cannot be less 
stringent than the emissions control that is achieved in practice by 
the best-controlled similar source. The MACT floors for existing 
sources can be less stringent than floors for new sources, but they 
cannot be less stringent than the average emissions 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 considerations of the cost of achieving the 
emissions reductions, any non-air quality health and environmental 
impacts and energy requirements.
    The EPA is then required to review these technology-based standards 
and 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 conducting this 
review, the EPA is not obliged to completely recalculate the prior MACT 
determination. NRDC v. EPA, 529 F.3d 1077, 1084 (DC Cir. 2008).
    The second stage in standard-setting focuses on reducing any 
remaining (i.e., ``residual'') risk according to CAA section 112(f). 
This provision requires, first, that the EPA prepare a Report to 
Congress discussing (among other things) methods of calculating the 
risks posed (or potentially posed) by sources after implementation of 
the MACT standards, the public health significance of those risks and 
the EPA's recommendations as to legislation regarding such remaining 
risk. The 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 the EPA's obligation under 
CAA section 112(f)(2) to analyze and address residual risk.
    CAA section 112(f)(2) requires the EPA to determine, for source 
categories subject to certain MACT standards, whether those emissions 
standards 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 one in one million,'' the 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, the EPA may adopt standards equal 
to existing MACT standards if the EPA determines that the existing 
standards are sufficiently protective. NRDC v. EPA, 529 F.3d at 1083 
(``If EPA determines that the existing technology-based standards 
provide an `ample margin of safety,' then the agency is free to readopt 
those standards during the residual risk rulemaking.''). The 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.
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    \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.
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    Section 112(f)(2) of the CAA expressly preserves our use of the 
two-step process for developing standards to address any residual risk 
and our interpretation of ``ample margin of safety'' developed in the 
National Emissions 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). 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 to be set (unless 
an even more stringent standard is necessary to prevent, taking into 
consideration costs,

[[Page 1271]]

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) preserves the EPA's interpretation 
set out in the Benzene NESHAP, and the United States Court of Appeals 
for the District of Columbia Circuit in NRDC v. EPA, 529 F.3d 1077, 
concluded that the EPA's interpretation of subsection 112(f)(2) is a 
reasonable one. See NRDC v. EPA, 529 F.3d at 1083 (``[S]ubsection 
112(f)(2)(B) expressly incorporates EPA's interpretation of the Clean 
Air Act from the Benzene standard, complete with a citation to the 
Federal Register.''). See also, A Legislative History of the Clean Air 
Act Amendments of 1990, volume 1, p. 877 (Senate debate on Conference 
Report). We also 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 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 risks 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, the EPA 
does not define ``rigid line[s] of acceptability,'' but rather 
considers 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 NRDC v. EPA, 824 F.2d 1146, 1165 
(DC Cir. 1987) (Vinyl Chloride Decision)) recognizing that our world is 
not risk-free.
    In the Benzene NESHAP, we stated that the ``EPA will generally 
presume that if the risk to [the maximum exposed] individual is no 
higher than approximately one in 10 thousand, that risk level is 
considered acceptable.'' 54 FR 38045. We discussed the maximum 
individual lifetime cancer risk (or maximum individual risk (MIR)) 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 upper bound 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 upper-bound 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 one million (one in 
10 thousand) ``provides a benchmark for judging the acceptability of 
maximum individual lifetime cancer risk (MIR), but does not constitute 
a rigid line for making that determination.'' Id. Further, in the 
Benzene NESHAP, we noted that, ``Particular attention will also be 
accorded to the weight of evidence presented in the risk assessment of 
potential carcinogenicity or other health effects of a pollutant. While 
the same numerical risk may be estimated for an exposure to a pollutant 
judged to be a known human carcinogen, and to a pollutant considered a 
possible human carcinogen based on limited animal test data, the same 
weight cannot be accorded to both estimates. In considering the 
potential public health effects of the two pollutants, the Agency's 
judgment on acceptability, including the MIR, will be influenced by the 
greater weight of evidence for the known human carcinogen.'' Id. at 
38046.
    The agency also explained in the 1989 Benzene NESHAP the following: 
``In establishing a presumption for MIR, rather than a 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-emissions 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. [* * *] 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 CAA section 112.''
    In NRDC v. EPA, 529 F.3d 1077, 1082 (DC Cir. 2008), the Court of 
Appeals held that CAA section 112(f)(2) ``incorporates EPA's 
`interpretation' of the Clean Air Act from the Benzene Standard, and 
the text of this provision draws no distinction between carcinogens and 
non-carcinogens.'' Additionally, the Court held there is nothing on the 
face of the statute that limits the Agency's section 112(f) assessment 
of risk to carcinogens. Id. at 1081-82. In the NRDC case, the 
petitioners argued, among other things, that CAA section 112(f)(2)(B) 
applied only to non-carcinogens. The DC Circuit rejected this position, 
holding that the text of that provision ``draws no distinction between 
carcinogens and non-carcinogens,'' Id., and that Congress' 
incorporation of the Benzene standard applies equally to carcinogens 
and non-carcinogens.

[[Page 1272]]

    In the ample margin of safety decision process, the agency again 
considers all of the health risks 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 CAA section 112(f). 54 FR 
38046.

B. Does this action apply to me?

    The NESHAP and associated 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 industrial 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 proposed 
action include:

    Table 2--NESHAP and Industrial Source Categories Affected by This
                             Proposed Action
------------------------------------------------------------------------
     NESHAP and source category        NAICS Code \1\     MACT Code \2\
------------------------------------------------------------------------
Group IV Polymers and Resins
    Acrylic-Butadiene-Styrene                   325211              1302
     Production.....................
    Methyl Methacrylate-                        325211              1317
     Acrylonitrile-Butadiene-Styrene
     Production \3\.................
    Methyl Methacrylate-Butadiene-              325211              1318
     Styrene Production.............
    Nitrile Resins Production \3\...            325211              1342
    Polyethylene Terephthalate                  325211              1328
     Production.....................
    Polystyrene Production..........            325211              1331
    Styrene-Acrylonitrile Production            325211              1338
Pesticide Active Ingredient             325199, 325320              0911
 Production.........................
Polyether Polyols Production........            325199              1625
------------------------------------------------------------------------
\1\ North American Industry Classification System.
\2\ Maximum Achievable Control Technology.
\3\ There are no longer any operating facilities in either the Methyl
  Methacrylate-Acrylonitrile-Butadiene-Styrene Production or Nitrile
  Resins Production source categories, and none are anticipated to begin
  operation in the future. Therefore, this proposal does not address
  these source categories.

C. Where can I get a copy of this document and other related 
information?

    In addition to being available in the docket, an electronic copy of 
this proposal will also be available on the World Wide Web (WWW) 
through the Technology Transfer Network (TTN). Following signature by 
the EPA Administrator, a copy of this 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/atw/rrisk/rtrpg.html. The TTN provides information and technology exchange in 
various areas of air pollution control.
    Additional information is available on the residual risk and 
technology review (RTR) 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.

D. What should I consider as I prepare my comments for the EPA?

    Submitting CBI. Do not submit information containing CBI to the EPA 
through http://www.regulations.gov or email. 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 the EPA, 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 the EPA's 
electronic public docket without prior notice. Information marked as 
CBI will not be disclosed except in accordance with procedures set 
forth in 40 CFR part 2. Send or deliver information identified as CBI 
only to the following address: Nick Parsons, c/o OAQPS Document Control 
Officer (C404-02), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711, 
Attn: Docket ID No. EPA-HQ-OAR-2011-0435.

II. Background

A. What are the source categories addressed by this action?

1. Group IV Polymers and Resins Production Source Categories
    The National Emission Standards for Hazardous Air Pollutant 
Emissions: Group IV Polymers and Resins were promulgated on September 
12, 1996 (61 FR 48208), and codified at 40 CFR part 63, subpart JJJ. 
The Group IV Polymers and Resins MACT standards apply to major sources 
and regulate HAP emissions from seven source categories: acrylonitrile 
butadiene styrene resin (ABS), styrene acrylonitrile resin (SAN), 
methyl methacrylate acrylonitrile butadiene styrene resin (MABS), 
methyl methacrylate butadiene styrene resin (MBS), polystyrene resin, 
poly (ethylene terephthalate) resin (PET) and nitrile resin.
    The Group IV Polymers and Resins MACT standards regulate HAP 
emissions resulting from the production of thermoplastics. A 
thermoplastic is a resin that softens with heat and rehardens to a 
rigid material upon cooling, without generally showing any change in 
the physical properties of the thermoplastic, even with repeated 
heating and cooling. Thermoplastics are composed of high-molecular-
weight polymers which are synthesized from monomers; the thermoplastics 
covered

[[Page 1273]]

in these seven source categories, with one exception, use styrene 
monomer as the basic feedstock. The thermoplastics included in these 
source categories 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 these polymers 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) material recovery; and 
(4) finishing (i.e., blending, aging, coagulation, washing and drying).
    Sources of HAP emissions from thermoplastics production include raw 
material storage vessels, continuous and batch process vents, 
wastewater operations, heat exchangers and equipment leaks. The Group 
IV Polymers and Resins MACT standards include a combination of 
equipment standards and emission limits for the various emission 
sources, which vary in stringency in some cases among the source 
categories.
    To meet the requirements of the Group IV Polymers and Resins MACT 
standards, the typical control devices used to reduce organic HAP 
emissions from process vents include flares, incinerators, absorbers, 
carbon adsorbers and condensers. In addition, emissions of hydrochloric 
acid (HCl) are controlled using scrubbers. Emissions from storage 
vessels are controlled by fixed roofs with closed vent systems routed 
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 and heat exchangers are 
typically reduced by leak detection and repair (LDAR) work practice 
programs and, in some cases, by equipment modifications. Each of the 
five Group IV Polymers and Resins source categories addressed in this 
proposal are discussed further below. Two of the Group IV Polymers and 
Resins source categories, MABS and nitrile resins, no longer have any 
operating facilities in the U.S. and we do not anticipate any will 
begin to operate in the future. Therefore, this proposal does not 
address these source categories.\2\
---------------------------------------------------------------------------

    \2\ It is the EPA's practice in these circumstances to not 
conduct unnecessary risk and technology reviews for source 
categories that will no longer have sources operating in the U.S. 
See, e.g., 75 FR 65068, 65075, n.5 (Oct. 21, 2010) and 76 FR 22566, 
22575, n.5 (Apr. 21, 2011).
---------------------------------------------------------------------------

a. Acrylonitrile Butadiene Styrene Resin (ABS)
    ABS consist of a terpolymer of acrylonitrile, butadiene and styrene 
and can be synthesized by emulsion, suspension and continuous mass 
polymerization. The majority of ABS resin production is by batch 
emulsion. Typical products made from ABS resins are piping, 
refrigerator door liners and food compartments, automotive components, 
telephones, luggage and cases, toys, mobile homes and margarine tubs.
    We identified five currently operating ABS facilities subject to 
the Group IV Polymers and Resins MACT standards. Styrene, acrylonitrile 
and 1,3-butadiene account for the majority of the HAP emissions from 
the ABS production processes at these facilities (approximately 156 tpy 
and 76 percent of the total HAP emissions by mass). These facilities 
also reported relatively small emissions of 23 other HAP. We estimate 
that the MACT-allowable emissions (i.e., the maximum emission levels 
allowed if in compliance with the MACT standards) from this source 
category are approximately equal to the reported, actual emissions. For 
more detail about this estimate of the ratio of actual to MACT-
allowable emissions and the estimation of MACT-allowable emission 
levels and associated risks and impacts, see the memorandum, MACT 
Allowable Emissions and Risks for the Pesticide Active Ingredient, 
Polyether Polyols, and Polymers and Resins IV Production Source 
Categories, in the docket for this rulemaking.
b. Styrene Acrylonitrile Resin (SAN)
    SAN resins are copolymers of styrene and acrylonitrile, and they 
may be synthesized by emulsion, suspension and continuous mass 
polymerization; however, the majority of production is by batch 
emulsion. Typical uses include automobile instrument panels and 
interior trim and housewares.
    We identified two currently operating SAN facilities subject to the 
Group IV Polymers and Resins MACT standards. Ethyl benzene and styrene 
account for the majority of the HAP emissions from the SAN production 
processes at these facilities (approximately 2 tpy and 82 percent of 
the total HAP emissions by mass). These facilities also reported 
relatively small emissions of methylene chloride and acrylonitrile. We 
estimate that the MACT-allowable emissions (i.e., the maximum emission 
levels allowed if in compliance with the MACT standards) from this 
source category are approximately equal to the reported, actual 
emissions. For more detail about this estimate of the ratio of actual 
to MACT-allowable emissions and the estimation of MACT-allowable 
emission levels and associated risks and impacts, see the memorandum, 
MACT Allowable Emissions and Risks for the Pesticide Active Ingredient, 
Polyether Polyols, and Polymers and Resins IV Production Source 
Categories, in the docket for this rulemaking.
c. Methyl Methacrylate Butadiene Styrene Resin (MBS)
    MBS resins are prepared by grafting methyl methacrylate and styrene 
onto a styrene-butadiene rubber in an emulsion process. The product is 
a two-phase polymer used as an impact modifier for rigid polyvinyl 
chloride products. These products are used for applications in 
packaging, building and construction.
    We identified two currently operating MBS facilities subject to the 
Group IV Polymers and Resins MACT standards. Methyl methacrylate and 
1,3-butadiene account for the majority of the HAP emissions from the 
MBS production processes at these facilities (approximately 4 tpy and 
75 percent of the total HAP emissions by mass). These facilities also 
reported relatively small emissions of ethyl acrylate, methanol, 
styrene and HCl. We estimate that the MACT-allowable emissions (i.e., 
the maximum emission levels allowed if in compliance with the MACT 
standards) from this source category are approximately equal to the 
reported, actual emissions. For more detail about this estimate of the 
ratio of actual to MACT-allowable emissions and the estimation of MACT-
allowable emission levels and associated risks and impacts, see the 
memorandum, MACT Allowable Emissions and Risks for the Pesticide Active 
Ingredient, Polyether Polyols, and Polymers and Resins IV Production 
Source Categories, in the docket for this rulemaking.
d. Polystyrene Resin
    Polystyrene resins are those produced by the polymerization of 
styrene monomer. This type of resin can be produced by three methods: 
(1) Suspension polymerization (operated in batch mode); (2) mass 
(operated in a continuous mode); and (3) emulsion process (operated in 
a continuous mode). The mass and suspension methods are the most 
commercially

[[Page 1274]]

significant, whereas use of the emulsion process has decreased 
significantly since the mid-1940s. The uses for polystyrene resin 
include packaging and one-time use, expandable polystyrene beads, 
electronics, resellers and compounding, consumer and institutional 
products and furniture, building or construction uses. A wide variety 
of consumer and construction products are made from polystyrene resins, 
including disposable dinnerware, shower doors, light diffusers, soap 
dishes, insulation board, food containers, drain pipes, audio and video 
tape, picnic coolers, loose fill packaging and tubing.
    We identified 11 currently operating polystyrene resin facilities 
subject to the Group IV Polymers and Resins MACT standards. Styrene 
accounts for the majority of the HAP emissions from the polystyrene 
resin production processes at these facilities (approximately 85 tpy 
and 94 percent of the total HAP emissions by mass). These facilities 
also reported relatively small emissions of eight other HAP. We 
estimate that the MACT-allowable emissions (i.e., the maximum emission 
levels allowed if in compliance with the MACT standards) from this 
source category are approximately equal to the reported, actual 
emissions. For more detail about this estimate of the ratio of actual 
to MACT-allowable emissions and the estimation of MACT-allowable 
emission levels and associated risks and impacts, see the memorandum, 
MACT Allowable Emissions and Risks for the Pesticide Active Ingredient, 
Polyether Polyols, and Polymers and Resins IV Production Source 
Categories, in the docket for this rulemaking.
e. Poly (Ethylene Terephthalate) Resin (PET)
    Three different types of resins are made by sources covered by the 
PET source category: Solid-state resins (PET bottle grade resins), 
polyester film and engineering resins. They are all thermoplastic 
linear condensation polymers based on dimethyl terephthalate or 
terephthalic acid (TPA). PET meltphase polymer is used in the 
production of all three of these resins. PET production can occur via 
either a batch or continuous process. The most common use of PET solid-
state resins is in soft drink bottles, and some industrial fiber-graded 
polyester (e.g., for tire cord) is also produced from PET solid-state 
resins. The most common uses of PET film are photographic film and 
magnetic media. PET is used extensively in the manufacture of synthetic 
fibers (i.e., polyester fibers), which compose the largest segment of 
the synthetic fiber industry. The most common uses of polyester fibers 
are apparel, home furnishings, carpets, fiberfill and other industrial 
processes.
    We identified 15 currently operating PET facilities subject to the 
Group IV Polymers and Resins MACT standards. Ethylene glycol, 
acetaldehyde and methanol account for the majority of the HAP emissions 
from the PET production processes at these facilities (approximately 
1,048 tpy and 89 percent of the total HAP emissions by mass). These 
facilities also reported relatively small emissions of 34 other HAP. We 
estimate that the MACT-allowable emissions (i.e., the maximum emission 
levels allowed if in compliance with the MACT standards) from this 
source category are approximately equal to the reported, actual 
emissions. For more detail about this estimate of the ratio of actual 
to MACT-allowable emissions and the estimation of MACT-allowable 
emission levels and associated risks and impacts, see the memorandum, 
MACT Allowable Emissions and Risks for the Pesticide Active Ingredient, 
Polyether Polyols, and Polymers and Resins IV Production Source 
Categories, in the docket for this rulemaking.
2. Pesticide Active Ingredient Production
    The National Emission Standards for Hazardous Air Pollutants for 
Pesticide Active Ingredient Production were promulgated on June 23, 
1999 (64 FR 33549), and codified at 40 CFR part 63, subpart MMM. The 
Pesticide Active Ingredient (PAI) MACT standards apply to major sources 
and regulate HAP emissions resulting from the production of active 
ingredients in insecticides, herbicides, fungicides and related 
products. Typically, the active ingredients subject to the PAI MACT 
standards are subsequently formulated with inert ingredients to create 
end-product pesticides for application. The MACT standards do not apply 
to the formulation of end-product pesticides or to other types of 
active ingredients, such as biocides.
    PAI are made from a number of raw materials in a variety of 
processes. A process often consists of several steps, which may include 
reaction, crystallization, washing, solvent extraction, distillation 
and/or drying.
    The HAP emission sources at PAI production facilities include 
storage vessels, process vents, equipment leaks, wastewater systems, 
heat exchange systems, bag dumps and product dryers. In the production 
of PAI, HAP are used primarily as reactants or extraction solvents; 
some of the PAI products are also HAP. The MACT standards for PAI 
production include a combination of equipment standards and emission 
limits for the various emission sources.
    To meet the requirements of the PAI MACT standards, the typical 
control devices used to reduce emissions from process vents include 
flares, incinerators, absorbers, carbon adsorbers and condensers. In 
addition, emissions of HCl are controlled using scrubbers. Emissions 
from storage vessels are controlled by fixed roofs with closed vent 
systems routed 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 and heat exchangers 
are typically reduced by LDAR work practice programs and, in some 
cases, by equipment modifications. Fabric filters are used to control 
particulate matter (PM) emissions from product dryers and bag dumps.
    We identified 17 currently operating facilities subject to the PAI 
MACT standards. Toluene, methanol and methylene chloride account for 
the majority of the HAP emissions from the PAI production processes at 
these facilities (approximately 177 tpy and 51 percent of the total HAP 
emissions by mass). A variety of chemicals are used in the production 
of PAI, and these facilities also reported emissions of 67 other HAP. 
We estimate that the actual emissions level is representative of the 
MACT-allowable level (i.e., the maximum emission levels allowed if in 
compliance with the MACT standards) for all emissions sources except 
process vents. 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 for process vents, the MACT-
allowable level for organic HAP emissions could be up to five times the 
actual emissions and the MACT-allowable level for chlorine and HCl 
emissions could be up to six times the actual emissions from this 
source category. For more detail about this estimate of the ratio of 
actual to MACT-allowable emissions and the estimation of MACT-allowable 
emission levels and associated risks and impacts, see the memorandum, 
MACT Allowable Emissions and Risks for the Pesticide Active Ingredient, 
Polyether Polyols, and Polymers and Resins IV Production Source 
Categories, in the docket for this rulemaking.

[[Page 1275]]

3. Polyether Polyols Production
    The National Emission Standards for Hazardous Air Pollutant 
Emissions for Polyether Polyols Production were promulgated on June 1, 
1999 (64 FR 29419), and codified at 40 CFR part 63, subpart PPP. The 
Polyether Polyols (PEPO) MACT standards apply to major sources and 
regulate HAP emissions resulting from the production of chemical 
products with repeating ether linkages (i.e., -R-O-R-) formed by the 
reaction of ethylene oxide, propylene oxide or other cyclic ethers with 
compounds having one or more reactive hydrogens. (This definition 
excludes materials regulated as glycols or glycol ethers under the 
National Emission Standards for Organic Hazardous Air Pollutants From 
the Synthetic Organic Chemical Manufacturing Industry (HON).) PEPO do 
not have significant uses of their own but are used to make a variety 
of other products. Urethane grade PEPO (i.e., those that are free of 
water) are used as raw material in the production of polyurethanes, 
including slabstock and molded flexible foams, rigid foams and other 
polyurethanes, including microcellular products, surface coatings, 
elastomers, fibers, adhesives and sealants. Nonurethane PEPO are used 
as surfactants, lubricants, degreasing agents, hydraulic fluids, 
cosmetics and pharmaceuticals.
    PEPO can be produced by either polymerization of epoxides (i.e., a 
three-membered cyclic ether, such as ethylene oxide or propylene oxide) 
or tetrahydrofuran (THF). The former process is usually conducted as a 
batch process, while production of polyols using THF is generally a 
continuous process. Ethylene oxide and propylene oxide are both HAP, 
but THF is not. For the MACT regulation, two subcategories of PEPO were 
created based on the use of either epoxides or THF in polymerization.
    The HAP emission sources at PEPO production facilities include 
process vents, storage vessels, equipment leaks and wastewater, and 
some facilities have cooling towers or other heat exchangers. In the 
production of PEPO, HAP are used primarily as reactants or extraction 
solvents; some of the PEPO products are also HAP compounds. The MACT 
standards for PEPO production include emission limits for process 
vents, a combination of equipment standards and work practices for 
storage vessels, wastewater and equipment leaks, and work practice 
standards for cooling towers.
    To meet the requirements of the PEPO MACT standards, the typical 
control devices used to reduce emissions from storage vessels are fixed 
roofs with closed vent systems routed 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 and heat exchangers are typically reduced by LDAR work 
practice programs and, in some cases, by equipment modifications. 
Controls for process vents for facilities that use THF as a reactant 
generally use scrubbers. Epoxide emissions from process vents are 
typically controlled by scrubbers or combustion devices, but some 
facilities use extended cookout as a pollution prevention technique. 
Extended cookout reduces the amount of unreacted ethylene oxide and/or 
propylene oxide (epoxides) in the reactor. This is accomplished by 
allowing the product to react for a longer time period, thereby having 
less unreacted epoxides and reducing epoxides emissions that may have 
otherwise occurred. Emissions from catalyst extraction and other 
processes are generally vented to the same control device as the 
epoxide emissions or are minimal if the extended cookout practice is 
used.
    We identified 23 currently operating facilities subject to the PEPO 
MACT standards. Ethylene glycol, ethylene oxide and propylene oxide 
account for the majority of the HAP emissions from the PEPO production 
processes at these facilities (approximately 269 tpy and 61 percent of 
the total HAP emissions by mass). A variety of chemicals are used in 
the production of PEPO, and these facilities also reported emissions of 
81 other HAP. We estimate that the actual emissions level is 
representative of the MACT-allowable level (i.e., the maximum emission 
levels allowed if in compliance with the MACT standards) for all 
emissions sources except batch process vents and process vents that use 
organic HAP in catalyst extraction at units producing PEPO products 
using epoxides. As it is possible that the capture systems and control 
devices used at some facilities achieve greater emission reductions in 
the organic non-epoxide HAP than what is required by the NESHAP for 
these process vents, the MACT-allowable level for organic non-epoxide 
HAP emissions could be up to five times the actual emissions from this 
source category. For more detail about this estimate of the ratio of 
actual to MACT-allowable emissions and the estimation of MACT-allowable 
emission levels and associated risks and impacts, see the memorandum, 
MACT Allowable Emissions and Risks for the Pesticide Active Ingredient, 
Polyether Polyols, and Polymers and Resins IV Production Source 
Categories, in the docket for this rulemaking.

B. What data collection activities were conducted to support this 
proposed action?

    To perform the risk assessments for these source categories, we 
developed data sets for these seven source categories (five Group IV 
Polymers and Resins categories, PAI and PEPO) based on information in 
the 2005 National Emissions Inventory (NEI) (available at http://www.epa.gov/chief/net/2005inventory.html). The NEI is a database that 
contains information about sources that emit criteria air pollutants, 
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. 
The EPA collects this information and releases an updated version of 
the NEI database every 3 years. We reviewed the NEI data and made 
changes where necessary to ensure the proper facilities were included 
and to ensure the proper processes were allocated to each source 
category. We also reviewed the emissions and other data to identify 
data anomalies that could affect risk estimates, such as whether a 
pollutant was expected to be emitted from facilities in a source 
category or whether an emission point was located within a facility's 
fenceline. The NEI data were also reviewed by industry trade groups, 
including the American Chemistry Council and the Society of Chemical 
Manufacturers and Affiliates. Where the EPA received new information in 
response to these data review by industry, including updated emissions 
data and process information, facility closure information and 
information that some facilities were not subject to the PAI, PEPO or 
Group IV Polymers and Resins MACT standards, we revised the NEI data 
where we concluded the comments supported such adjustment. We obtained 
updated emissions data and process information, found that some 
facilities had closed and that others were no longer subject to the 
PAI, PEPO or Group IV Polymers and Resins MACT standards. In general, 
we found that emissions from these source categories had decreased from 
the values reported in the 2005 NEI, due to factors such as the 
installation of additional controls at the facility,

[[Page 1276]]

duplication of emissions in the inventory, or emissions misappropriated 
to the wrong source category. We used this reviewed and revised data 
set to conduct the risk assessment and other analyses for each source 
category. Due to the uncertainties in the data (e.g., most emission 
estimates in the data set are the result of emission factors rather 
than test data), along with our general finding that emissions were 
less than those reported in the 2005 NEI, we believe that the data set 
provides a conservative estimate of the risk from these source 
categories. Further details on the changes made to the 2005 NEI data 
can be found in the memorandum, Emissions Data and Acute Risk Factor 
Used in Residual Risk Modeling: Pesticide Active Ingredients, Polyether 
Polyols, and Group IV Polymers and Resins, which is in the docket for 
this rulemaking.
    To conduct the technology review, we primarily relied on 
information downloaded from the reasonably available control technology 
(RACT)/best available control technology (BACT)/lowest achievable 
emission rate (LAER) Clearinghouse (RBLC) for processes in Agricultural 
Chemical Manufacturing (for PAI controls), Polymer and Resin Production 
(for Group IV Polymers and Resins controls) and the Synthetic Organic 
Chemical Manufacturing Industry (SOCMI) (for PAI, PEPO and Group IV 
Polymers and Resins controls) with permits dating back to the 
promulgation dates of each MACT regulation.
    To evaluate unregulated emission points in the Group IV Polymers 
and Resins MACT standards, we relied on existing data submitted to the 
EPA during development of the MACT, information submitted after 
proposal of the MACT standards and information submitted with requests 
for reconsideration of standards.

III. Analyses Performed

A. How did we address unregulated emissions sources?

    For the Group IV Polymers and Resins source categories, we 
identified one subcategory--PET sources using a continuous TPA high 
viscosity multiple end finisher process--consisting of one facility 
that was not subject to standards for process contact cooling towers 
(PCCT) or equipment leaks. While the promulgated rule includes 
provisions for PCCT for this subcategory, the facility is not required 
to comply with these provisions due to an indefinite stay in the 
compliance date provisions issued by the EPA in response to a request 
to reconsider the emission limits for this equipment. For this 
facility, we also identified the absence of a standard for equipment 
leaks, which in the absence of an enforceable standard is a potential 
significant emissions source for this facility, even though its 
operators currently voluntarily conduct their own LDAR program. For the 
one facility in this subcategory, we are proposing to set standards for 
PCCT and equipment leaks under CAA section 112(d)(2) and (d)(3) in this 
action. The results and proposed decisions based on the analyses 
performed pursuant to CAA section 112(d)(2) and 112(d)(3) are presented 
in section IV.E.1 of this preamble. While we also identified the 
absence of a standard for wastewater for the acrylonitrile styrene 
resin/alpha methyl styrene acrylonitrile resin (ASA/AMSAN) subcategory 
of the SAN source category, the only facility in this subcategory has 
permanently closed, and no new ASA/AMSAN operations are expected to 
begin operation in the United States. As stated previously and as 
established in prior risk and technology review rulemakings, it is not 
EPA's practice to unnecessarily conduct risk and technology reviews for 
source categories that will no longer have sources operating in the 
United States. Therefore, we are not addressing this emission point in 
this proposed action.

B. How did we estimate risks posed by the source categories?

    The EPA conducted risk assessments that provided estimates of the 
MIR posed by the HAP emissions from each source in each source 
category, the hazard index (HI) for chronic exposures to HAP with the 
potential to cause noncancer health effects and the hazard quotient 
(HQ) for acute exposures to HAP with the potential to cause noncancer 
health effects. The assessments also provided estimates of the 
distribution of cancer risks within the exposed populations, cancer 
incidence and an evaluation of the potential for adverse environmental 
effects for each source category. The risk assessments consisted of 
seven primary steps, as discussed below. The docket for this rulemaking 
contains the following document which provides more information on the 
risk assessment inputs and models: Draft Residual Risk Assessment for 7 
Source Categories. The methods used to assess risks (as described in 
the seven primary steps below) are consistent with those peer-reviewed 
by a panel of the EPA's Science Advisory Board (SAB) in 2009 and 
described in their peer review report issued in 2010; they are also 
consistent with the key recommendations contained in that report.
1. Establishing the Nature and Magnitude of Actual Emissions and 
Identifying the Emissions Release Characteristics
    As discussed in section II.B, we created the preliminary data sets 
for the seven source categories using data in the 2005 NEI, 
supplemented by data collected from industry or industry trade 
associations when available.
2. Establishing the Relationship Between Actual Emissions and MACT-
Allowable Emissions Levels
    The available emissions data in the NEI and from other sources 
typically represent the mass of HAP actually emitted during the 
specified annual time period. These ``actual'' emission levels can be 
lower than the emission levels a facility might be allowed to emit and 
still comply with the MACT standards. The emissions level allowed to be 
emitted by the MACT standards is referred to as the ``MACT-allowable'' 
emissions level. This represents the highest emissions level that could 
be emitted by facilities without violating the MACT standards.
    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 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 
risks at the MACT-allowable level is inherently reasonable because 
these risks reflect the maximum level sources could emit and still 
comply with national emission standards. We continue to take this view, 
for the reasons presented in those discussions. 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.) We also continue to 
take this view, for the reasons explained in those prior discussions.
    As described above, the actual emissions data were compiled based 
on the NEI and information gathered from facilities through industrial 
trade associations. To estimate emissions at the MACT-allowable level, 
we developed a ratio of MACT-allowable to actual emissions for each 
emissions source type in each source category, based on the level of 
control required by the MACT standards compared to the level of 
reported actual emissions and

[[Page 1277]]

available information on the level of control achieved by the emissions 
controls in use. For example, if there was information to suggest 
several facilities in a source category were controlling storage tank 
emissions by 98 percent, while the MACT standards required only 92-
percent control, we would estimate that MACT-allowable emissions from 
these emission points could be as much as four times higher (8-percent 
allowable emissions compared with 2 percent actually emitted), and the 
ratio of MACT-allowable to actual would be 4:1 for this emission point 
type at the facilities in this source category. After developing these 
ratios for each emission point type in each source category, we next 
applied these ratios on a facility-by-facility basis to the maximum 
chronic risk values from the inhalation risk assessment to obtain 
facility-specific maximum risk values based on MACT-allowable 
emissions. Further explanation of this evaluation is provided in the 
technical document, MACT Allowable Emissions and Risks for the 
Pesticide Active Ingredient, Polyether Polyols, and Polymers and Resins 
IV Production Source Categories, which is available in the docket for 
this action.
3. Conducting Dispersion Modeling, Determining Inhalation Exposures, 
and Estimating Individual and Population Inhalation Risks
    Both long-term and short-term inhalation exposure concentrations 
and health risks from each facility in the source categories addressed 
in this proposal were estimated using the Human Exposure Model (HEM) 
(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 estimates and quantitative dose-response information.
    The dispersion model used by HEM-3 is AERMOD, which is one of the 
EPA's preferred models for assessing pollutant concentrations from 
industrial facilities.\3\ 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 (1991) of 
hourly surface and upper air observations for 189 meteorological 
stations, selected to provide coverage of the United States and Puerto 
Rico. A second library of United States Census Bureau census block \4\ 
internal point locations and populations provides the basis of human 
exposure calculations (U.S. 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 the 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.
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    \3\ U.S. EPA. Revision to the Guideline on Air Quality Models: 
Adoption of a Preferred General Purpose (Flat and Complex Terrain) 
Dispersion Model and Other Revisions (70 FR 68218, November 9, 
2005).
    \4\ A census block is generally the smallest geographic area for 
which census statistics are tabulated.
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    In developing the risk assessment for chronic exposures, we used 
the estimated annual average ambient air concentration of each of the 
HAP emitted by each source for which we have emissions data in the 
source category. The air concentrations at each nearby census block 
centroid were used as a surrogate for the chronic inhalation exposure 
concentration for all people who reside in that census block. We 
calculated the MIR for each facility as the cancer risk associated with 
a continuous lifetime (24 hours per day, 7 days per week and 52 weeks 
per year for a 70-year period) exposure to the maximum concentration at 
the centroid of inhabited census blocks. Individual cancer risks were 
calculated by multiplying the estimated lifetime exposure to the 
ambient concentration of each of the HAP (in micrograms per cubic meter 
([micro]g/m\3\)) 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 1 microgram of the 
pollutant per cubic meter of air. For residual risk assessments, we 
generally use URE values from the EPA's Integrated Risk Information 
System (IRIS).\5\ For carcinogenic pollutants without EPA IRIS values, 
we look to other reputable sources of cancer dose-response values, 
often using California EPA (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 the EPA, we may use such 
dose-response values in place of, or in addition to, other values, if 
appropriate.
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    \5\ The IRIS information is available at http://www.epa.gov/IRIS.
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    We note here that several carcinogens have a mutagenic mode of 
action.\6\ Of these compounds, polycyclic organic matter (POM) is 
emitted by facilities in the PEPO and PET source categories, and vinyl 
chloride is emitted by facilities in the PEPO and the PAI source 
categories. For these compounds, the age-dependent adjustment factors 
(ADAF) described in the EPA's Supplemental Guidance for Assessing 
Susceptibility from Early-Life Exposure to Carcinogens \7\ were 
applied. This adjustment has the effect of increasing the estimated 
lifetime risks for these pollutants by a factor of 1.6.\8\ In addition, 
the EPA expresses carcinogenic potency for compounds in the POM 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, the EPA's Science Policy Council \9\ 
recommends applying the Supplemental Guidance to all carcinogenic 
polycyclic aromatic hydrocarbons for which risk estimates are based on 
relative potency. Accordingly, we have applied the ADAF to 
benzo[a]pyrene equivalent portion of all POM mixtures.
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    \6\ 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: Memorandum from W.H. 
Farland, dated June 14, 2006. http://epa.gov/osa/spc/pdfs/CGIWGCommunication_II.pdf.
    \7\ 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.
    \8\ Only one of these mutagenic compounds, benzo[a]pyrene, is 
emitted by any of the sources covered by this proposal.
    \9\ U.S. EPA, 2005. Science Policy Council Cancer Guidelines 
Implementation Workgroup Communication I: Memorandum from W.H. 
Farland, dated October 4, 2005, to Science Policy Council. http://www.epa.gov/osa/spc/pdfs/canguid1.pdf.
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    Incremental individual lifetime cancer risks associated with 
emissions from the source categories were estimated as the sum of the 
risks for each of the carcinogenic HAP (including those classified as 
carcinogenic to humans, likely to be carcinogenic to humans, and 
suggestive evidence of

[[Page 1278]]

carcinogenic potential \10\) emitted by the modeled sources. Cancer 
incidence and the distribution of individual cancer risks for the 
population within 50 km of any source were also estimated for the 
source categories as part of these assessments by summing individual 
risks. A distance of 50 km is consistent with both the analysis 
supporting the 1989 Benzene NESHAP (54 FR 38044) and the limitations of 
Gaussian dispersion models, including AERMOD.
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    \10\ These classifications also coincide with the terms ``known 
carcinogen, probable carcinogen, and possible carcinogen,'' 
respectively, which are the terms advocated in the EPA's previous 
Guidelines for Carcinogen Risk Assessment, published in 1986 (51 FR 
33992, September 24, 1986). Summing the risks of these individual 
compounds to obtain the cumulative cancer risks is an approach that 
was recommended by the EPA's SAB in their 2002 peer review of the 
EPA's National Air Toxics Assessment (NATA) entitled, NATA--
Evaluating the National-scale Air Toxics Assessment 1996 Data--an 
SAB Advisory, available at: http://yosemite.epa.gov/sab/
sabproduct.nsf/214C6E915BB04E14852570CA007A682C/$File/
ecadv02001.pdf.
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    To assess risk of noncancer health effects from chronic exposures, 
we summed the HQ for each of the 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 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 from the EPA's IRIS 
database is not available, a value from the following prioritized 
sources for chronic dose-response values: (1) The Agency for Toxic 
Substances and Disease Registry Minimum Risk Level, 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''; (2) 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 (3) as noted above, a scientifically 
credible dose-response value that has been developed in a manner 
consistent with the EPA guidelines and has undergone a peer review 
process similar to that used by the EPA, in place of or in concert with 
other values.
    Screening estimates of acute exposures and risks were also 
evaluated for each of the HAP at the point of highest off-site exposure 
for each facility (i.e., not just the census block centroids), assuming 
that a person is located at this spot at a time when both the peak 
(hourly) emission rates from each emission point at the facility and 
worst-case dispersion conditions occur. The acute HQ is the estimated 
acute exposure divided by the acute dose-response value. In each case, 
acute HQ values were calculated using best available, short-term health 
threshold values. These acute dose-response values, which are described 
below, include the acute REL, acute exposure guideline levels (AEGL) 
and emergency response planning guidelines (ERPG) for 1-hour exposure 
durations. As discussed below, we used conservative assumptions for 
emission rates, meteorology and exposure location for our acute 
analysis.
    As described in the CalEPA's Air Toxics Hot Spots Program Risk 
Assessment Guidelines, Part I, The Determination of Acute Reference 
Exposure Levels for Airborne Toxicants, an acute REL value (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.'' Acute REL values are 
based on the most sensitive, relevant, adverse health effect reported 
in the medical and toxicological literature. Acute REL values are 
designed to protect the most sensitive sub-populations (e.g., 
asthmatics) by the inclusion of margins of safety. Because margins of 
safety are incorporated to address data gaps and uncertainties, 
exceeding the REL value does not automatically indicate an adverse 
health impact.
    AEGL values were derived in response to recommendations from the 
National Research Council (NRC). 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),\11\ ``the NRC's previous name for acute exposure 
levels--community emergency exposure levels--was replaced by the term 
AEGL 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 sites.'' 
This document also states that AEGL values ``represent threshold 
exposure limits for the general public and are applicable to emergency 
exposures ranging from 10 minutes to 8 hours.'' The document lays out 
the purpose and objectives of AEGL by stating (page 21) that ``the 
primary purpose of the AEGL program and the National Advisory Committee 
for Acute Exposure Guideline Levels for Hazardous Substances 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 ``[i]t 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.''
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    \11\ NAS, 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 
milligrams per cubic meter (mg/m\3\) 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 values are derived for use in emergency response, as described 
in the American Industrial Hygiene Association's document titled, 
Emergency Response Planning Guidelines (ERPG) Procedures and 
Responsibilities (http://www.aiha.org/1documents/committees/ERPSOPs2006.pdf), which states that, ``Emergency Response Planning 
Guidelines were developed for emergency planning and are intended as

[[Page 1279]]

health-based guideline concentrations for single exposures to 
chemicals.''\12\ 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 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 or developing irreversible or other serious health effects 
or symptoms which could impair an individual's ability to take 
protective action.''
---------------------------------------------------------------------------

    \12\ 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, a severity level 1 value AEGL or ERPG has not been developed 
because the types of effects for these chemicals are not consistent 
with the AEGL-1/ERPG-1 definitions; 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. When AEGL-1/ERPG-1 
values are available, they are used in our acute risk assessments.
    Acute REL values for 1-hour exposure durations are typically lower 
than their corresponding AEGL-1 and ERPG-1 values. Even though their 
definitions are slightly different, AEGL-1 values are often similar to 
the corresponding ERPG-1 values, and AEGL-2 values are often similar to 
ERPG-2 values. Maximum HQ values from our acute screening risk 
assessments typically result when basing them on the acute REL value 
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 
dose-response value (usually the AEGL-1 and/or the ERPG-1 value).
    To develop screening estimates of acute exposures in the absence of 
hourly emissions data, generally we first develop estimates of maximum 
hourly emissions rates by multiplying the average actual annual hourly 
emission rates by a default factor to cover routinely variable 
emissions. We choose the factor to use based on process knowledge and 
engineering judgment and with awareness of a Texas study of short-term 
emissions variability, which showed that most peak emission events in a 
heavily-industrialized 4-county area (Harris, Galveston, Chambers and 
Brazoria Counties, Texas) were less than twice the annual average 
hourly emission rate. The highest peak emissions event was 74 times the 
annual average hourly emission rate, and the 99th percentile ratio of 
peak hourly emissions rate to the annual average hourly emissions rate 
was 9.\13\ This analysis is provided in the Draft Residual Risk 
Assessment for 7 Source Categories report, which is available in the 
docket for this action. Considering this analysis, to account for more 
than 99 percent of the peak hourly emissions, we apply a conservative 
screening multiplication factor of 10 to the average annual hourly 
emissions rate in our acute exposure screening assessments as our 
default approach. However, we use a factor other than 10 if we have 
information that indicates that a different factor is appropriate for a 
particular source category. For these source categories, a factor of 10 
was applied to all emissions, with two exceptions. For certain 
facilities with volatile organic compound (VOC) emissions greater than 
876 tpy and for several facilities with emissions from equipment leaks, 
a factor of two was applied. A further discussion of why this factor 
was chosen can be found in the memorandum, Emissions Data and Acute 
Risk Factor Used in Residual Risk Modeling: Pesticide Active 
Ingredients, Polyether Polyols, and Group IV Polymers and Resins, 
available in the docket for this rulemaking.
---------------------------------------------------------------------------

    \13\ See http://www.tceq.state.tx.us/compliance/field_ops/eer/index.html or docket to access the source of these data.
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    As part of our acute risk assessment process, for cases where 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 potential for acute impacts of concern. The 
data refinements considered include using a peak-to-mean hourly 
emissions ratio based on source category-specific knowledge or data 
(rather than 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. Such an evaluation could include a more complete 
statistical treatment of the key parameters and elements adopted in 
this screening analysis. However, we recognize that having this level 
of data is rare, hence our use of the multiplier approach.
    To better characterize the potential health risks associated with 
estimated acute exposures to HAP, and in response to a key 
recommendation from the SAB's peer review of the EPA's RTR risk 
assessment methodologies,\14\ we generally examine a wider range of 
available acute health metrics (e.g., REL, AEGL) than we do for our 
chronic risk assessments. This is in response to the SAB's 
acknowledgement that there are generally more data gaps and 
inconsistencies in acute reference values than there are in chronic 
reference values. In some cases, when Reference Value Arrays\15\ for 
HAP have been developed, we consider additional acute values (i.e., 
occupational and international values) to provide a more complete risk 
characterization.
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    \14\ The SAB peer review of RTR Risk Assessment Methodologies is 
available at: http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
    \15\ U.S. EPA. (2009) Chapter 2.9 Chemical Specific Reference 
Values for Formaldehyde in Graphical Arrays of Chemical-Specific 
Health Effect Reference Values for Inhalation Exposures (Final 
Report). U.S. Environmental Protection Agency, Washington, DC, EPA/
600/R-09/061, and available on-line at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=211003.
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4. Conducting Multipathway Exposure and Risk Screening
    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 process. In the first step, we determined whether any facilities 
emitted any HAP known to be persistent and bio-accumulative in the 
environment (PB-HAP). There are 14 PB-HAP compounds or compound classes 
identified for this screening in the EPA's Air Toxics Risk Assessment 
Library (available at http://www.epa.gov/ttn/fera/risk_atra_vol1.html). They are cadmium compounds, chlordane, chlorinated 
dibenzodioxins and furans, dichlorodiphenyldichloroethylene, 
heptachlor, hexachlorobenzene, hexachlorocyclohexane, lead compounds, 
mercury compounds, methoxychlor, polychlorinated biphenyls (PCB), POM, 
toxaphene and trifluralin.

[[Page 1280]]

    In the second step of the screening process, we determined whether 
the facility-specific emission rates of each of the emitted PB-HAP were 
large enough to create the potential for significant non-inhalation 
human or environmental risks under reasonable worst-case conditions. To 
facilitate this step, we have developed emission rate thresholds for 
several of these PB-HAP using a hypothetical worst-case screening 
exposure scenario developed for use in conjunction with the EPA's Total 
Risk Integrated Methodology Fate, Transport and Ecological Exposure 
(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 negatives 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 of the PB-HAP in each source category were compared to the TRIM-
Screen emission threshold values for each of these PB-HAP to assess the 
potential for significant human health risks or environmental risks via 
non-inhalation pathways.
5. Assessing Risks Considering Emissions Control Options
    In addition to assessing baseline inhalation risks and screening 
for potential multipathway risks, for some source categories, we also 
estimated risks considering the potential emission reductions that 
would be achieved by the particular control options under 
consideration. In these cases, the expected emissions reductions were 
applied to the specific HAP and emission points in the source category 
dataset to develop corresponding estimates of risk reductions.
6. Conducting Other Risk-Related Analyses: Facility-Wide Assessments
    To put the source category risks in context, we examined the risks 
from the entire ``facility,'' where the facility includes all HAP-
emitting operations within a contiguous area and under common control. 
In other words, for each facility that includes one or more sources 
from a source category under review, we examined the HAP emissions not 
only from that source category, but also emissions of HAP from all 
other emission sources at the facility. The emissions data for 
generating these ``facility-wide'' risks were obtained from the 2005 
NEI. We analyzed risks due to the inhalation of HAP that are emitted 
``facility-wide'' for the populations residing within 50 km of each 
facility, consistent with the methods used for the source category 
analysis described above. For these facility-wide risk analyses, the 
modeled source category risks were compared to the facility-wide risks 
to determine the portion of facility-wide risks that could be 
attributed to each of the seven source categories addressed in this 
proposal. We specifically examined the facility that was associated 
with the highest estimate of risk and determined the percentage of that 
risk attributable to the source category of interest. The risk 
documentation available through the docket for this action provides all 
facility-wide risks and the percentage of source category contribution 
for all source categories assessed.
    The methodology and results of the facility-wide analyses for each 
source category are included in the residual risk documentation as 
referenced in sections IV though VI of this preamble, which is 
available in the docket for this action.
7. Considering Uncertainties in Risk Assessment
    Uncertainty and the potential for bias are inherent in all risk 
assessments, including those performed for the source categories 
addressed in this proposal. Although uncertainty exists, we believe the 
approach taken, which used conservative tools and assumptions, ensures 
that our decisions are health-protective. A brief discussion of the 
uncertainties in the emissions data sets, dispersion modeling, 
inhalation exposure estimates and dose-response relationships follows 
below. A more thorough discussion of these uncertainties is included in 
the risk assessment documentation (Draft Residual Risk Assessment for 7 
Source Categories (September 2011)), which is available in the docket 
for this action.
a. 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, the degree to which data 
are incomplete or missing, the degree to which assumptions made to 
complete the data sets are accurate, errors in estimating emissions 
values and other factors. The emission values considered in this 
analysis generally are annual totals that do not reflect short-term 
fluctuations during the course of a year or variations from year to 
year. In contrast, the estimates of peak hourly emission rates for the 
acute effects screening assessment were based on emission adjustment 
factors applied to the average annual hourly emission rates (the 
default factor is 10 for the initial screening), which are intended to 
account for emission fluctuations due to normal facility operations. In 
some cases, more refined estimates, using lower emission adjustment 
factors that reflected consideration of category-specific information, 
were used for source categories where the screening estimates did not 
``screen out'' all sources and more specific information was available.
b. Uncertainties in Dispersion Modeling
    While the analysis employed the EPA's recommended regulatory 
dispersion model, AERMOD, we recognize that there is uncertainty in 
ambient concentration estimates associated with any model, including 
AERMOD. Where possible, model options (e.g., rural/urban, plume 
depletion, chemistry) were selected to provide an overestimate of 
ambient air concentrations of the HAP rather than underestimates. 
However, because of practicality and data limitation reasons, some 
factors (e.g., meteorology, building downwash) have the potential in 
some situations to overestimate or 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 HAP concentrations.
c. 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 
between census blocks in the modeling domain were not considered.\16\ 
Not considering short or long-term population mobility does not bias 
the estimate of the theoretical MIR, nor does it affect the estimate of 
cancer incidence because the total population number remains the same. 
It does, however, affect the shape of the distribution of individual 
risks across the affected

[[Page 1281]]

population, shifting it toward higher estimated individual risks at the 
upper end and reducing the number of people estimated to be at lower 
risks, thereby increasing the estimated number of people at specific 
high risk levels (e.g., 1-in-1 million).
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    \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.
---------------------------------------------------------------------------

    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. Using the census 
block centroid to predict chronic exposures tends to over-predict 
exposures for people in the census block who live farther from the 
facility and under-predict 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 it is an unbiased 
estimate of average risk and incidence.
    The assessments evaluate the cancer inhalation risks associated 
with continuous pollutant exposures over a 70-year period, which is the 
assumed lifetime of an individual. 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, in most cases, result in an overestimate both in 
individual risk levels and in the total estimated number of cancer 
cases. However, in rare cases, where a facility maintains or increases 
its emission levels beyond 70 years, residents live beyond 70 years at 
the same location, and the residents spend most of their days at that 
location, then the risks could potentially be underestimated. 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 as 
high, depending on the 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\
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    \17\ U.S. EPA. 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 other factors specific to the acute exposure assessment. 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 be worst-case actual 
exposures, as it is unlikely that a person would be located at the 
point of maximum exposure during the time of worst-case impact.
d. 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 on dose-response uncertainty that is 
brought out in the 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 residual risk documentation, which is available in the docket 
for this action.
    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 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. To err on the side of ensuring 
adequate health protection, the EPA typically uses the upper bound 
estimates rather than lower bound or central tendency estimates in our 
risk assessments, an approach that may 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 reference dose (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. The UF are applied to derive reference values that are 
intended to protect against appreciable risk of deleterious effects. 
The UF are commonly default values,\20\ e.g., factors of 10 or 3, used 
in the absence of compound-specific data; where data are available, UF 
may also be developed using compound-specific information. When data 
are limited, more assumptions are needed and more UF are used. Thus, 
there may be a greater

[[Page 1282]]

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 the 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 using observed 
animal (usually rodent) or human toxicity data in the development of 
the RfC. 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 sub-chronic 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 they more often use 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 lowest 
observed adverse effect (exposure) level to no observed adverse effect 
(exposure) level 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 short-term dose-response values at different levels of severity 
should be factored into the risk characterization as potential 
uncertainties.
    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, chronic noncancer 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. For a group of 
compounds that are either unspeciated or do not have reference values 
for every individual compound (e.g., glycol ethers) we conservatively 
use the most protective reference value to estimate risk from 
individual compounds in the group of compounds.
    Additionally, chronic reference values for several 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 may re-evaluate residual risks 
for the final rulemaking if these reviews are completed prior to our 
taking final action for these source categories and if a dose-response 
metric changes enough to indicate that the risk assessment supporting 
this notice may significantly understate human health risk.
e. Uncertainties in the Multipathway and Environmental Effects 
Screening Assessment
    We generally assume that when exposure levels are not anticipated 
to adversely affect human health, they also are not anticipated to 
adversely affect the environment. For each source category, we 
generally rely on the site-specific levels of PB-HAP emissions to 
determine whether a full assessment of the multipathway and 
environmental effects is necessary. Our screening methods use worst-
case scenarios to determine whether multipathway impacts might be 
important. The results of such a process are biased high for the 
purpose of screening out potential impacts. Thus, when individual 
pollutants or facilities screen out, we are confident that the 
potential for multipathway impacts is negligible. On the other hand, 
when individual pollutants or facilities do not screen out, it does not 
mean that multipollutant impacts are significant, only that we cannot 
rule out that possibility.

C. How did we consider the risk results in making decisions for this 
proposal?

    As discussed in the previous section of this preamble, we apply a 
two-step process for determining whether to develop standards to 
address residual risk. In the first step, the EPA determines whether 
risks are acceptable. This determination ``considers all health 
information, including risk estimation uncertainty, and includes a 
presumptive level on maximum individual lifetime [cancer] risk (MIR) 
\21\ of approximately one in 10 thousand [i.e., 100 in 1 million].'' 54 
FR 38045. In the second step of the process, the EPA determines what 
level of the standard is needed to provide an ample margin of safety 
``in consideration of all health information, including the number of 
persons at risk levels higher than approximately one in one million, as 
well as other relevant factors, including costs and economic impacts, 
technological feasibility, and other factors relevant to each 
particular decision.'' Id.
---------------------------------------------------------------------------

    \21\ Although defined as ``maximum individual risk,'' MIR refers 
only to cancer risk. MIR, one metric for assessing cancer risk, is 
the estimated risk were an individual exposed to the maximum level 
of a pollutant for a lifetime.
---------------------------------------------------------------------------

    In past residual risk actions, the EPA presented and considered a 
number of human health risk metrics associated with emissions from the 
category under review, including: The MIR; the numbers of persons in 
various risk ranges; cancer incidence; the maximum noncancer HI; and 
the maximum acute noncancer hazard. See, e.g., 75 FR 65068, 65072-74 
(Oct. 21, 2010), and 76 FR 22566, 22575 (Apr. 21, 2011). In estimating 
risks, the EPA considered sources under review that are located near 
each other and that affect the same population. The EPA developed risk 
estimates based on the actual emissions from the source category under 
review as well as based on the maximum emissions allowed pursuant to 
the source category MACT standards. The EPA also discussed and 
considered risk estimation uncertainties. The EPA is providing this 
same type of information in support of these actions.
    The agency is considering all available health information to 
inform our determinations of risk acceptability and ample margin of 
safety under CAA section 112(f). Specifically, as explained in the 
Benzene NESHAP, ``the first step judgment on acceptability cannot be 
reduced to any single factor'' and thus ``[t]he Administrator believes 
that the acceptability of risk under [previous] section 112 is best 
judged on the basis of a broad set of health risk measures and 
information.'' 54 FR 38046.

[[Page 1283]]

Similarly, with regard to making the ample margin of safety 
determination, as stated in the Benzene NESHAP, ``[i]n 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 cost and economic impacts of 
controls, technological feasibility, uncertainties, and any other 
relevant factors.'' Id.
    The agency acknowledges that the Benzene NESHAP provides 
flexibility regarding what factors the EPA might consider in making our 
determinations and how they might be weighed for each source category. 
In responding to comment on our policy under the Benzene NESHAP, the 
EPA explained that: ``The policy chosen by the Administrator permits 
consideration of multiple measures of health risk. Not only can the MIR 
figure be considered, but also incidence, the presence of noncancer 
health effects and the uncertainties of the risk estimates. In this 
way, the effect on the most exposed individuals can be reviewed as well 
as the impact on the general public. These factors can then be weighed 
in each individual case. This approach complies with the Vinyl Chloride 
mandate that the Administrator ascertain an acceptable level of risk to 
the public by employing [her] expertise to assess available data. It 
also complies with the Congressional intent behind the CAA, which did 
not exclude the use of any particular measure of public health risk 
from the EPA's consideration with respect to CAA section 112 
regulations and, thereby, implicitly permits consideration of any and 
all measures of health risk which the Administrator, in [her] judgment, 
believes are appropriate to determining what will `protect the public 
health.' '' 54 FR 38057.
    Thus, the level of the MIR is only one factor to be weighed in 
determining acceptability of risks. The Benzene NESHAP explains ``an 
MIR of approximately one in 10 thousand should ordinarily be the upper 
end of the range of acceptability. As risks increase above this 
benchmark, they become presumptively less acceptable under CAA section 
112, and would be weighed with the other health risk measures and 
information in making an overall judgment on acceptability. Or, the 
agency may find, in a particular case, that a risk that includes MIR 
less than the presumptively acceptable level is unacceptable in the 
light of other health risk factors.'' Id. at 38045. Similarly, with 
regard to the ample margin of safety analysis, the Benzene NESHAP 
states that: ``EPA believes the relative weight of the many factors 
that can be considered in selecting an ample margin of safety can only 
be determined for each specific source category. This occurs mainly 
because technological and economic factors (along with the health-
related factors) vary from source category to source category.'' Id. at 
38061.

D. How did we perform the technology review?

    Our technology review is focused on the identification and 
evaluation of ``developments in practices, processes, and control 
technologies.'' If a review of available information identifies such 
developments, then we conduct an analysis of the technical feasibility 
of requiring the implementation of these developments, along with the 
impacts (costs, emission reductions, risk reductions, etc.). We then 
make a decision on whether it is necessary to amend the regulation to 
require compliance with revised standards in light of these 
developments. This has become our standard practice in conducting 
technology reviews. See, e.g., 75 FR 65068, 65083 (October 21, 2010).
    Based on specific knowledge of each source category, we began by 
identifying known developments in practices, processes and control 
technologies. For the purpose of this exercise, we considered any of 
the following to be a ``development'':
     Any add-on control technology or other equipment that was 
not identified and considered during MACT development;
     Any improvements in add-on control technology or other 
equipment (that was identified and considered during MACT development) 
that could result in significant additional emission reduction;
     Any work practice or operational procedure that was not 
identified and considered during MACT development; and
     Any process change or pollution prevention alternative 
that could be broadly applied that was not identified and considered 
during MACT development.
    In addition to looking back at practices, processes or control 
technologies reviewed at the time we developed the MACT standards, we 
reviewed a variety of sources of data to aid in our evaluation of 
whether there were additional practices, processes or controls to 
consider. One of these sources of data was subsequent air toxics rules. 
Since the promulgation of the MACT standards for the source categories 
addressed in this proposal, the EPA has developed air toxics 
regulations for a number of additional source categories. In these 
subsequent air toxic regulatory actions, we consistently evaluated any 
new practices, processes and control technologies. We reviewed the 
regulatory requirements and/or technical analyses associated with these 
subsequent regulatory actions to identify any practices, processes and 
control technologies considered in these efforts that could possibly be 
applied to emission sources in the source categories under this current 
RTR review.
    We also consulted the EPA's RBLC. The terms ``RACT,'' ``BACT'' and 
``LAER'' are acronyms for different program requirements under the CAA 
provisions addressing the national ambient air quality standards. 
Control technologies classified as RACT, BACT or LAER apply to 
stationary sources depending on whether the sources are existing or new 
and on the size, age and location of the facility. BACT and LAER (and 
sometimes RACT) are determined on a case-by-case basis, usually by 
state or local permitting agencies. The EPA established the RBLC to 
provide a central data base of air pollution technology information 
(including technologies required in source-specific permits) to promote 
the sharing of information among permitting agencies and to aid in 
identifying future possible control technology options that might apply 
broadly to numerous sources within a category or apply only on a 
source-by-source basis. The RBLC contains over 5,000 air pollution 
control permit determinations that can help identify appropriate 
technologies to mitigate many air pollutant emission streams. We 
searched this database to determine whether any practices, processes or 
control technologies are included for the types of processes used for 
emission sources (e.g., tanks or vents) in the source categories under 
consideration in this proposal.
    We also reviewed other information sources, such as state or local 
permitting agency databases and industry-supported databases.

E. What other issues are we addressing in this proposal?

    In addition to the RTR performed regarding the NESHAP, we are also 
proposing revisions to the NESHAP to address emissions during periods 
of startup, shutdown and malfunction (SSM) and revisions to require 
electronic reporting of emissions test results.

[[Page 1284]]

1. Startup, Shutdown and Malfunction (SSM)
    The United States Court of Appeals for the District of Columbia 
Circuit vacated portions of two provisions in the EPA's CAA Section 112 
regulations governing the emissions of HAP during periods of SSM. 
Sierra Club v. EPA, 551 F.3d 1019 (DC Cir. 2008), cert. denied, 130 S. 
Ct. 1735 (U.S. 2010). Specifically, the Court vacated the SSM exemption 
contained in 40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), that are part of 
a regulation, commonly referred to as the ``General Provisions Rule,'' 
that the EPA promulgated under section 112 of the CAA. When 
incorporated into CAA section 112(d) regulations for specific source 
categories, these two provisions exempt sources from the requirement to 
comply with the otherwise applicable CAA section 112(d) emission 
standard during periods of SSM.
    As we have done in other recent risk and technology review 
rulemakings, we are proposing the elimination of the SSM exemption in 
each of the three MACT standards addressed by this rule. See, e.g., 76 
FR 22568, 22573 (Apr. 21, 2011). Consistent with Sierra Club v. EPA, 
the EPA is proposing standards in these rules that apply at all times. 
We are also proposing several revisions to the General Provisions 
Applicability table in each of the MACT standards. For example, we are 
proposing to eliminate the incorporation of the General Provisions' 
requirement that the source develop an SSM plan. We also are proposing 
to eliminate or revise certain recordkeeping and reporting related to 
the SSM exemption. The EPA has attempted to ensure that we have not 
included in the proposed regulatory language any provisions that are 
inappropriate, unnecessary or redundant in the absence of the SSM 
exemption. We are specifically seeking comment on whether there are any 
such provisions that we have inadvertently incorporated or overlooked.
    In proposing the standards in these rules, the EPA has taken into 
account startup and shutdown periods and has not proposed different 
standards for those periods because we expect the difference in 
emission levels during periods of startup and shutdown are 
insignificant and that facilities in these source categories should be 
able to comply with the standards during these times.
    Periods of startup, normal operation and shutdown are all 
predictable and routine aspects of a source's operations. However, by 
contrast, malfunction is defined as a ``sudden, infrequent, and not 
reasonably preventable failure of air pollution control and monitoring 
equipment, process equipment or a process to operate in a normal or 
usual manner * * *.'' (40 CFR 63.2). The EPA has determined that CAA 
section 112 does not require that emissions that occur during periods 
of malfunction be factored into development of CAA section 112 
standards. Under section 112, emissions standards for new sources must 
be no less stringent than the level ``achieved'' by the best controlled 
similar source and for existing sources generally must be no less 
stringent than the average emission limitation ``achieved'' by the best 
performing 12 percent of sources in the category. There is nothing in 
section 112 that directs the agency to consider malfunctions in 
determining the level ``achieved'' by the best performing or best 
controlled sources when setting emission standards. Moreover, while the 
EPA accounts for variability in setting emissions standards consistent 
with the CAA section 112 caselaw, nothing in that caselaw requires the 
agency to consider malfunctions as part of that analysis. Section 112 
uses the concept of ``best controlled'' and ``best performing'' unit in 
defining the level of stringency that CAA section 112 performance 
standards must meet. Applying the concept of ``best controlled'' or 
``best performing'' to a unit that is malfunctioning presents 
significant difficulties, as malfunctions are sudden and unexpected 
events.
    Further, accounting for malfunctions would be difficult, if not 
impossible, given the myriad different types of malfunctions that can 
occur across all sources in the category and given the difficulties 
associated with predicting or accounting for the frequency, degree and 
duration of various malfunctions that might occur. As such, the 
performance of units that are malfunctioning is not ``reasonably'' 
foreseeable. See, e.g., Sierra Club v. EPA, 167 F. 3d 658, 662 (DC Cir. 
1999) (The EPA typically has wide latitude in determining the extent of 
data-gathering necessary to solve a problem. We generally defer to an 
agency's decision to proceed on the basis of imperfect scientific 
information, rather than to ``invest the resources to conduct the 
perfect study.''). See also, Weyerhaeuser v. Costle, 590 F.2d 1011, 
1058 (DC Cir. 1978) (``In the nature of things, no general limit, 
individual permit, or even any upset provision can anticipate all upset 
situations. After a certain point, the transgression of regulatory 
limits caused by `uncontrollable acts of third parties,' such as 
strikes, sabotage, operator intoxication or insanity, and a variety of 
other eventualities, must be a matter for the administrative exercise 
of case-by-case enforcement discretion, not for specification in 
advance by regulation.''). In addition, the goal of a best controlled 
or best performing source is to operate in such a way as to avoid 
malfunctions of the source, and accounting for malfunctions could lead 
to standards that are significantly less stringent than levels that are 
achieved by a well-performing non-malfunctioning source. The EPA's 
approach to malfunctions is consistent with section 112 and is a 
reasonable interpretation of the statute.[rparb]
    In the event that a source fails to comply with the applicable CAA 
section 112(d) standards as a result of a malfunction event, the EPA 
would determine an appropriate response based on, among other things, 
the good faith efforts of the source to minimize emissions during 
malfunction periods, including preventative and corrective actions, as 
well as root cause analyses to ascertain and rectify excess emissions. 
The EPA would also consider whether the source's failure to comply with 
the CAA section 112(d) standard was, in fact, ``sudden, infrequent, not 
reasonably preventable'' and was not instead ``caused in part by poor 
maintenance or careless operation.'' 40 CFR 63.2 (definition of 
malfunction).
    Finally, the EPA recognizes that even equipment that is properly 
designed and maintained can sometimes fail and that such failure can 
sometimes cause an exceedance of the relevant emission standard. (See, 
e.g., State Implementation Plans: Policy Regarding Excessive Emissions 
During Malfunctions, Startup, and Shutdown (Sept. 20, 1999); Policy on 
Excess Emissions During Startup, Shutdown, Maintenance, and 
Malfunctions (Feb. 15, 1983)). The EPA is, therefore, proposing to 
follow its recently established practice (see, e.g., 76 FR 22566, 
22573-74 (Apr. 21, 2011)) and add to the rules an affirmative defense 
to civil penalties for exceedances of emission limits that are caused 
by malfunctions. See proposed 40 CFR 63.1312 (Group IV Polymers and 
Resins), 40 CFR 63.1361 (PAI) and 40 CFR 63.1423 (PEPO). The 
regulations define ``affirmative defense'' to mean, in the context of 
an enforcement proceeding, a response or defense put forward by a 
defendant, regarding which the defendant has the burden of proof, and 
the merits of which are independently and objectively evaluated in a 
judicial or administrative proceeding. We also are proposing other 
regulatory provisions to specify the

[[Page 1285]]

elements that are necessary to establish this affirmative defense; the 
source must prove by a preponderance of the evidence that it has met 
all of the elements set forth in proposed 40 CFR 63.1310(k) (Group IV 
Polymers and Resins), 40 CFR 63.1360(k) (PAI) and 40 CFR 63.1420(i) 
(PEPO). (See 40 CFR 22.24). The criteria ensure that the affirmative 
defense is available only where the event that causes an exceedance of 
the emission limit meets the narrow definition of malfunction in 40 CFR 
63.2 (sudden, infrequent, not reasonable preventable and not caused by 
poor maintenance and or careless operation). For example, to 
successfully assert the affirmative defense, the source must prove by a 
preponderance of the evidence that excess emissions ``[w]ere caused by 
a sudden, infrequent, and unavoidable failure of air pollution control 
and monitoring equipment, process equipment, or a process to operate in 
a normal or usual manner * * *.'' The criteria also are designed to 
ensure that steps are taken to correct the malfunction, to minimize 
emissions in accordance with proposed 40 CFR 63.1310(j)(4) (Group IV 
Polymers and Resins), 40 CFR 63.1362(i) (PAI) and 40 CFR 63.1420(h)(4) 
(PEPO) and to prevent future malfunctions. For example, the source must 
prove by a preponderance of the evidence that ``[r]epairs were made as 
expeditiously as possible when the applicable emission limitations were 
being exceeded * * *'' and that ``[a]ll possible steps were taken to 
minimize the impact of the excess emissions on ambient air quality, the 
environment and human health * * *.'' In any judicial or administrative 
proceeding, the Administrator may challenge the assertion of the 
affirmative defense and, if the respondent has not met its burden of 
proving all of the requirements in the affirmative defense, appropriate 
penalties may be assessed in accordance with section 113 of the CAA 
(see also 40 CFR 22.27).
    The EPA included an affirmative defense in these proposed rules in 
an attempt to balance a tension, inherent in many types of air 
regulation, to ensure adequate compliance while simultaneously 
recognizing that despite the most diligent of efforts, emission limits 
may be exceeded under circumstances beyond the control of the source. 
The EPA must establish emission standards that ``limit the quantity, 
rate, or concentration of emissions of air pollutants on a continuous 
basis.'' 42 U.S.C. 7602(k) (defining ``emission limitation and emission 
standard''). See generally, Sierra Club v. EPA, 551 F.3d 1019, 1021 
(D.C. Cir. 2008). Thus, the EPA is required to ensure that section 112 
emissions limitations are continuous. The affirmative defense for 
malfunction events meets this requirement by ensuring that even where 
there is a malfunction, the emission limitation is still enforceable 
through injunctive relief. While ``continuous'' limitations, on the one 
hand, are required, there is also caselaw indicating that in many 
situations it is appropriate for the EPA to account for the practical 
realities of technology. For example, in Essex Chemical v. Ruckelshaus, 
486 F.2d 427, 433 (D.C. Cir. 1973), the District of Columbia Circuit 
acknowledged that, in setting standards under CAA section 111, 
``variant provisions'' such as provisions allowing for upsets during 
startup, shutdown and equipment malfunction ``appear necessary to 
preserve the reasonableness of the standards as a whole and that the 
record does not support the `never to be exceeded' standard currently 
in force.'' See also, Portland Cement Association v. Ruckelshaus, 486 
F.2d 375 (D.C. Cir. 1973). Though intervening caselaw such as Sierra 
Club v. EPA and the CAA 1977 amendments undermine the relevance of 
these cases today, they support the EPA's view that a system that 
incorporates some level of flexibility is reasonable. The affirmative 
defense simply provides for a defense to civil penalties for excess 
emissions that are proven to be beyond the control of the source. By 
incorporating an affirmative defense, EPA has formalized its approach 
to upset events. In a Clean Water Act setting, the Ninth Circuit 
required this type of formalized approach when regulating ``upsets 
beyond the control of the permit holder.'' Marathon Oil Co. v. EPA, 564 
F.2d 1253, 1272-73 (9th Cir. 1977). See, Weyerhaeuser Co. v. Costle, 
590 F.2d 1011, 1057-58 (D.C. Cir. 1978) (holding that an informal 
approach is adequate). The affirmative defense provisions give the EPA 
the flexibility to both ensure that its emission limitations are 
``continuous'' as required by 42 U.S.C. section 7602(k), and account 
for unplanned upsets and thus support the reasonableness of the 
standard as a whole.
    In addition to these changes in the provisions related to SSM, we 
are also proposing that there be no discharge to the atmosphere from 
any pressure relief device (PRD) on any equipment in HAP service within 
the process units for these seven source categories. To ensure 
compliance with this requirement, facility owners or operators would be 
required to install electronic indicators on each PRD that would be 
able to identify and record the time and duration of each pressure 
release and notify operators that a pressure release has occurred. 
While pressure release events may be associated with unplanned, 
nonroutine discharges that result from operator error, malfunctions or 
other unexpected causes that require immediate venting of gas from 
process equipment in order to avoid safety hazards or equipment damage, 
we are concerned that a large number of these releases that occur may 
emit large quantities of HAP, may not be identified and controlled in a 
timely manner and may be due to repeat problems that have not been 
corrected. These proposed provisions will clarify that such release 
events would be violations of the emissions standards of these rules. 
If any pressure release events that occur are related to a process or 
control device malfunction, the owner or operator could claim the 
affirmative defense described above.
2. Electronic Reporting
    We are proposing to add electronic reporting requirements to the 
PAI, PEPO and the Group IV Polymers and Resin Production NESHAP. The 
EPA must have performance test data to conduct effective reviews of CAA 
section 112 standards, as well as for many other purposes including 
compliance determinations, emission factor development and annual 
emission rate determinations. In conducting these required reviews, the 
EPA has found it ineffective and time consuming, not only for us, but 
also for regulatory agencies and source owners and operators, to 
locate, collect and submit performance test data because of varied 
locations for data storage and varied data storage methods. In recent 
years, though, stack testing firms have typically collected performance 
test data in electronic format, making it possible to move to an 
electronic data submittal system that would increase the ease and 
efficiency of data submittal and improve data accessibility.
    Through this proposal, the EPA is presenting a step to increase the 
ease and efficiency of data submittal and improve data accessibility. 
Specifically, the EPA is proposing that owners and operators of PAI, 
PEPO and Group IV Polymers and Resins facilities submit electronic 
copies of required performance test reports to the EPA's WebFIRE 
database. The WebFIRE database was constructed to store performance 
test data for use in developing emission factors. A description of the 
WebFIRE database is

[[Page 1286]]

available at http://cfpub.epa.gov/oarweb/index.cfm?action=fire.main.
    As proposed above, data entry would be through an electronic 
emissions test report structure called the Electronic Reporting Tool 
(ERT). The ERT would generate electronic report which would be 
submitted using the Compliance and Emissions Data Reporting Interface 
(CEDRI). The submitted report would be transmitted through the EPA's 
Central Data Exchange (CDX) network for storage in the WebFIRE database 
making submittal of data very straightforward and easy. A description 
of the ERT can be found at http://www.epa.gov/ttn/chief/ert/index.html 
and CEDRI can be accessed through the CDX Web site (http://www.epa.gov/cdx).
    The proposal to submit performance test data electronically to the 
EPA would apply only to those performance tests conducted using test 
methods that will be supported by the ERT. The ERT contains a specific 
electronic data entry form for most of the commonly used EPA reference 
methods. A listing of the pollutants and test methods supported by the 
ERT is available at http://www.epa.gov/ttn/chief/ert/index.html. We 
believe that industry would benefit from this proposed approach to 
electronic data submittal. Having these data, the EPA would be able to 
develop improved emission factors, make fewer information requests and 
promulgate better regulations.
    One major advantage of the proposed submittal of performance test 
data through the ERT is a standardized method to compile and store much 
of the documentation required to be reported by this rule. Another 
advantage is that the ERT clearly states what testing information would 
be required. Another important proposed benefit of submitting these 
data to the EPA at the time the source test is conducted is that it 
should substantially reduce the effort involved in data collection 
activities in the future. When the EPA has performance test data in 
hand, there will likely be fewer or less substantial data collection 
requests in conjunction with prospective required residual risk 
assessments or technology reviews. This would result in a reduced 
burden on both affected facilities (in terms of reduced manpower to 
respond to data collection requests) and the EPA (in terms of preparing 
and distributing data collection requests and assessing the results).
    State, local and tribal agencies could also benefit from more 
streamlined and accurate review of electronic data submitted to them. 
The ERT would allow for an electronic review process rather than a 
manual data assessment making review and evaluation of the source 
provided data and calculations easier and more efficient. Finally, 
another benefit of the proposed data submittal to WebFIRE 
electronically is that these data would greatly improve the overall 
quality of existing and new emissions factors by supplementing the pool 
of emissions test data for establishing emissions factors and by 
ensuring that the factors are more representative of current industry 
operational procedures. A common complaint heard from industry and 
regulators is that emission factors are outdated or not representative 
of a particular source category. With timely receipt and incorporation 
of data from most performance tests, the EPA would be able to ensure 
that emission factors, when updated, represent the most current range 
of operational practices. In summary, in addition to supporting 
regulation development, control strategy development and other air 
pollution control activities, having an electronic database populated 
with performance test data would save industry, state, local, tribal 
agencies and the EPA significant time, money and effort while also 
improving the quality of emission inventories and, as a result, air 
quality regulations.

IV. Analytical Results and Proposed Decisions for Group IV Polymers and 
Resins Source Categories

A. Acrylonitrile Butadiene Styrene Resin (ABS)

1. What are the results of the risk assessments?
a. Inhalation Risk Assessment Results
    Table 3 provides an overall summary of the inhalation risk 
assessment results for the source category.

                                                     Table 3--ABS Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                Maximum individual cancer risk                                     Maximum chronic noncancer
                                      (in 1 million) \2\                         Annual cancer             TOSHI \3\
                               --------------------------------  Population at     incidence   --------------------------------  Maximum off-site acute
   Number of  facilities \1\        Actual         Allowable    risk  >= 1-in-    (cases per        Actual         Allowable        noncancer HQ \4\
                                   emissions       emissions       1 million         year)         emissions       emissions
                                     level           level                                           level           level
--------------------------------------------------------------------------------------------------------------------------------------------------------
5.............................              30              30          32,000           0.003             0.2             0.2  HQREL = 2 acetaldehyde.
                                                                                                                                HQERPG-1 = 0.04
                                                                                                                                 acetaldehyde.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the ABS source category is the reproductive system.
\4\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of 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 dose-response value. See section III.B.3 of this preamble for explanation of acute dose-response values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table 3, the results of the inhalation risk 
assessment indicated the maximum lifetime individual cancer risk could 
be up to 30-in-1 million, the maximum chronic noncancer TOSHI value 
could be up to 0.2, and the maximum off-facility site acute HQ value 
could be up to 2, based on the actual emissions level and the REL value 
for acetaldehyde. The total estimated national cancer incidence from 
these facilities, based on actual emission levels, is 0.003 excess 
cancer cases per year or one case in every 333 years.
    Based on our analysis, we believe that actual emissions approximate 
emissions allowable under the MACT standards. Therefore, the risk 
results for MACT-allowable emissions are approximately equal to those 
for actual emissions. For

[[Page 1287]]

more detail about this estimate of the ratio of actual to MACT-
allowable emissions and the estimation of MACT-allowable emission 
levels and associated risks and impacts, see the memorandum, MACT 
Allowable Emissions and Risks for the Pesticide Active Ingredient, 
Polyether Polyols, and Polymers and Resins IV Production Source 
Categories, in the docket for this rulemaking.
    There were no reported emissions of PB-HAP; therefore, we do not 
expect potential for human health multipathway risks or adverse 
environmental impacts as a result of PB-HAP.
b. Facility-Wide Risk Assessment Results
    Table 4 displays the results of the facility-wide risk assessment. 
This assessment was conducted based on actual emission levels. For 
detailed facility-specific results, see Appendix 4 of the Draft 
Residual Risk Assessment for 7 Source Categories in the docket for this 
rulemaking.

           Table 4--ABS Facility-Wide Risk Assessment Results
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Number of facilities analyzed................................          5
Cancer Risk:*
    Estimated maximum facility-wide individual cancer risk            30
     (in 1 million)..........................................
    Number of facilities with estimated facility-wide                  0
     individual cancer risk of 100-in-1 million or more......
    Number of facilities at which the ABS source category              0
     contributes 50 percent or more to the facility-wide
     individual cancer risks of 100-in-1 million or more.....
    Number of facilities at which the ABS source category              4
     contributes 50 percent or more to the facility-wide
     individual cancer risk of 1-in-1 million or more........
Chronic Noncancer Risk:
    Maximum facility-wide chronic noncancer TOSHI............        < 1
    Number of facilities with facility-wide maximum noncancer          0
     TOSHI greater than 1....................................
    Number of facilities at which the ABS source category              0
     contributes 50 percent or more to the facility-wide
     maximum noncancer TOSHI of 1 or more....................
------------------------------------------------------------------------

    The facility-wide MIR from all HAP emissions at a facility that 
contains sources subject to the Group IV Polymers and Resins MACT 
standards for ABS resins is estimated to be 30-in-1 million, based on 
actual emissions. Of the 5 facilities included in this analysis, none 
have a facility-wide MIR of 100-in-1 million. There are 4 facilities 
with facility-wide MIR of 1-in-1 million or greater (MIR ranging from 
10 to 30 in a million). Each of these facilities has ABS production 
operations that contribute greater than 50 percent to the facility-wide 
risks.
    The facility-wide maximum individual chronic noncancer TOSHI is 
estimated to be less than 1, based on actual emissions. Of the 5 
facilities included in this analysis, none have facility-wide maximum 
chronic noncancer TOSHI values greater than 1.
c. What is our proposed decision regarding risk acceptability?
    As noted in section III.C of this preamble, we weigh all health 
risk factors in our risk acceptability determination, including the 
MIR; the number of persons in various cancer and noncancer risk ranges; 
cancer incidence; the maximum noncancer HI; the maximum acute noncancer 
HQ; the extent of noncancer risks; the potential for adverse 
environmental effects; distribution of cancer and noncancer risks in 
the exposed population; and risk estimation uncertainty (54 FR 38044, 
September 14, 1989).
    For the ABS source category, the risk analysis we performed 
indicates that the cancer risks to the individual most exposed could be 
up to 30-in-1 million due to both actual and allowable emissions. This 
value is considerably less than 100-in-1 million, which is the 
presumptive level of acceptability. The risk analysis also shows low 
cancer incidence (1 in every 333 years), no potential for human health 
multipathway effects, and that chronic noncancer health impacts are 
unlikely.
    We estimate that the worst-case acute HQ value could exceed a value 
of 1 for one HAP, acetaldehyde, with a potential maximum HQ up to 2 
based on the acute REL dose-response value. Only one of the five 
facilities in this source category had an estimated HQ greater than 1 
(REL of 2 for acetaldehyde). All other facilities modeled had an HQ 
less than 1. The maximum HQ based on an AEGL-1 or ERPG-1 dose-response 
value is 0.04 for acetaldehyde based on the ERPG-1. As described 
earlier in this preamble, the acute assessment includes some 
conservative assumptions and some uncertainties. Moreover, the REL are 
protective and designed to protect the most sensitive individuals in 
the population by inclusion of margins of safety and exposures above 
the REL do not necessarily indicate that adverse effects will occur. 
Considering the improbable assumption that worst-case meteorological 
conditions are present at the same time that maximum hourly emissions 
of acetaldehyde exceed the average hourly emission rate by a factor of 
10 at all emission points simultaneously, coincident with individuals 
being in the location of maximum impact, and considering the low acute 
HQ values based on the AEGL-1 and ERPG-1 dose-response values 
collectively with the REL value, we believe it is unlikely that HAP 
emissions from this source category would result in acute health 
effects.
    Our additional analysis of facility-wide risks showed that the 
maximum facility-wide cancer risk is 30-in-1 million and that the 
maximum chronic exposures are expected to be without appreciable risk 
of adverse noncancer health effects.
    The EPA has weighed the various health risk measures and health 
factors, including risk estimation uncertainty, discussed above and in 
section III.B.7 of this preamble, and we are proposing that the risks 
from the ABS source category are acceptable.
d. What is our proposed decision regarding ample margin of safety?
    We considered whether the MACT standards provide an ample margin of 
safety to protect public health. In this analysis, we investigated 
available emissions control options that might reduce the risk 
associated with emissions from the source category and considered this 
information along with all of the health risks and other health 
information considered in the risk acceptability determination.
    For the ABS source category, we identified only one control option 
to further address risks from equipment leaks. This control option 
would require sources to install leakless valves to prevent leaks from 
those components.

[[Page 1288]]

While approximately 15 percent of the emissions from this source 
category are due to equipment leaks, these emissions do not contribute 
to the maximum individual cancer risks estimated for the source 
category.
    We estimated HAP reduction resulting from this control option is 
approximately 6 tpy from the baseline actual emissions level. We 
estimated that achieving these reductions would involve a capital cost 
of approximately $11,000,000, a total annualized cost of about 
$1,500,000 and a cost effectiveness of $244,000 per ton of HAP 
emissions reduced. The additional control requirement would not achieve 
a reduction in the maximum individual cancer risks. We estimate that 
the MACT allowable emissions from this source category are 
approximately equal to the reported, actual emissions. Therefore, the 
estimated emission reduction, risk reduction and costs discussed above 
would also be applicable to the MACT allowable emissions level. We 
believe that the costs of this option are not reasonable, given the 
level of emission and risk reduction.
    In accordance with the approach established in the Benzene NESHAP, 
the EPA weighed all health risk measures and information considered in 
the risk acceptability determination, along with the costs and economic 
impacts of emissions controls, technological feasibility, uncertainties 
and other relevant factors in making our ample margin of safety 
determination. Considering the health risk information and the 
unreasonable cost effectiveness of the option identified, we propose 
that the existing MACT standards provide an ample margin of safety to 
protect public health and prevent an adverse environmental effect.
2. What are the results of the technology review?
    In the decade since the Group IV Polymers and Resins MACT standards 
were promulgated, the EPA has developed 19 air toxics regulations for 
source categories that emit organic HAP from the same type of emissions 
sources that are present in the five Group IV Polymers and Resins 
source categories addressed in this proposed action. We reviewed the 
regulatory requirements and/or technical analyses for these 19 
regulations for new practices, processes and control technologies. We 
also conducted a search of the RBLC for controls for VOC-SOCMI 
categories with permits dating back to 1997.
    We identified no advancements in practices, processes, and control 
technologies applicable to the emission sources in the Group IV 
Polymers and Resins source categories in our technology review.
3. What other actions are we proposing?
a. SSM Provisions
    We are proposing to eliminate the SSM exemption in the Group IV 
Polymers and Resins MACT standards. Consistent with Sierra Club v. EPA, 
the EPA is proposing that standards in this rule would apply at all 
times. We are proposing several revisions to 40 CFR part 63, subpart 
JJJ. Specifically, we are proposing to revise Table 1 to indicate that 
the requirements of 40 CFR 63.6(e) of the General Provisions do not 
apply. The 40 CFR 63.6(e) requires the owner or operator to act 
according to the general duty to ``operate and maintain any affected 
source, including associated air pollution control equipment and 
monitoring equipment, in a manner consistent with safety and good air 
pollution control practices for minimizing emissions.'' We are 
separately proposing to incorporate this general duty to minimize into 
40 CFR 63.1310(j)(4). The 40 CFR 63.6(e) also requires the owner or 
operator of an affected source to develop a written SSM plan. We are 
proposing to remove the SSM plan requirement. We are proposing to 
remove the explanation of applicability of emissions standards during 
periods SSM in 40 CFR 63.1310(j); remove the malfunction plan from 40 
CFR 63.1335(b); clarify that representative conditions do not include 
periods of SSM throughout the rule; remove references to periods of SSM 
in monitoring; remove the provisions for excused excursions from 40 CFR 
63.1334(g); and revise the SSM-associated recordkeeping and reporting 
requirements in 40 CFR 63.1335(b) to require reporting and 
recordkeeping for periods of malfunction. We are also proposing to 
revise Table 1 to indicate that SSM-related provisions in 40 CFR 
63.6(e)(1), 63.6(e)(3), 63.6(f)(1); 40 CFR 63.7(e)(1); 40 CFR 
63.8(c)(1); and 40 CFR 63.10(d)(5) of the General Provisions do not 
apply. We are also proposing to add requirements in 40 CFR 
63.1331(a)(9)) to clarify that PRD releases to the atmosphere are 
violations of the emissions standards and to require pressure release 
alarms and to add requirements in 40 CFR 63.1335(e)(9) to require 
reporting of any pressure device releases to the atmosphere with the 
periodic report. In addition, we are proposing to promulgate an 
affirmative defense against civil penalties for exceedances of emission 
standards caused by malfunctions, as well as criteria for establishing 
the affirmative defense.
b. Electronic Reporting
    To increase the ease and efficiency of data submittal and improve 
data accessibility, we are proposing to require the submission of 
electronic copies of required performance tests for test methods that 
are supported by the ERT to EPA's WebFIRE database. These provisions 
are added in 40 CFR 63.1335(e)(10).

B. Styrene Acrylonitrile Resin (SAN)

1. What are the results of the risk assessments?
a. Inhalation Risk Assessment Results
    Table 5 provides an overall summary of the inhalation risk 
assessment results for the source category.

                                                     Table 5--SAN Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                Maximum individual cancer risk                                     Maximum chronic noncancer
                                      (in 1 million) \2\                         Annual cancer             TOSHI \3\
                               --------------------------------  Population at     incidence   --------------------------------  Maximum off-site acute
   Number of  facilities \1\        Actual         Allowable    risk >= 1-in-1    (cases per        Actual         Allowable        noncancer HQ \4\
                                   emissions       emissions        million          year)         emissions       emissions
                                     level           level                                           level           level
--------------------------------------------------------------------------------------------------------------------------------------------------------
2.............................            0.03            0.03               0        0.000006          0.0002          0.0002  HQREL = 0.007 methylene
                                                                                                                                 chloride.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the SAN source category is the respiratory system.

[[Page 1289]]

 
\4\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of 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 dose-response value. See section III.B.3 of this preamble for explanation of acute dose-response values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table 5, the results of the inhalation risk 
assessment indicated the maximum lifetime individual cancer risk could 
be up to 0.03-in-1 million, the maximum chronic noncancer TOSHI value 
could be up to 0.0002, and the maximum off-facility site acute HQ value 
could be up to 0.007, based on the actual emissions level and the REL 
value for methylene chloride. The total estimated national cancer 
incidence from these facilities based on actual emission levels is 
0.000006 excess cancer cases per year or one case in every 166,666 
years.
    Based on our analysis, we believe that actual emissions approximate 
emissions allowable under the MACT standards. Therefore, the risk 
results for MACT-allowable emissions are approximately equal to those 
for actual emissions. For more detail about this estimate of the ratio 
of actual to MACT-allowable emissions and the estimation of MACT-
allowable emission levels and associated risks and impacts, see the 
memorandum, MACT Allowable Emissions and Risks for the Pesticide Active 
Ingredient, Polyether Polyols, and Polymers and Resins IV Production 
Source Categories, in the docket for this rulemaking.
    There were no reported emissions of PB-HAP; therefore, we do not 
expect potential for human health multipathway risks or adverse 
environmental impacts as a result of PB-HAP.
b. Facility-Wide Risk Assessment Results
    Table 6 displays the results of the facility-wide risk assessment. 
This assessment was conducted based on actual emission levels. For 
detailed facility-specific results, see Appendix 4 of the Draft 
Residual Risk Assessment for 7 Source Categories in the docket for this 
rulemaking.

           Table 6--SAN Facility-Wide Risk Assessment Results
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Number of facilities analyzed................................          2
Cancer Risk:
    Estimated maximum facility-wide individual cancer risk            20
     (in 1 million)..........................................
    Number of facilities with estimated facility-wide                  0
     individual cancer risk of 100-in-1 million or more......
    Number of facilities at which the SAN source category              0
     contributes 50 percent or more to the facility-wide
     individual cancer risks of 100-in-1 million or more.....
    Number of facilities at which the SAN source category              0
     contributes 50 percent or more to the facility-wide
     individual cancer risk of 1-in-1 million or more........
Chronic Noncancer Risk:
    Maximum facility-wide chronic noncancer TOSHI............          2
    Number of facilities with facility-wide maximum noncancer          1
     TOSHI greater than 1....................................
    Number of facilities at which the SAN source category              0
     contributes 50 percent or more to the facility-wide
     maximum noncancer TOSHI of 1 or more....................
------------------------------------------------------------------------

    The facility-wide MIR from all HAP emissions at a facility that 
contains sources subject to the Group IV Polymers and Resins MACT 
standards for SAN resins is estimated to be 20-in-1 million, based on 
actual emissions. Of the 2 facilities included in this analysis, none 
have a facility-wide MIR of 100-in-1 million. There are 2 facilities 
with facility-wide MIR of 1-in-1 million or greater (MIR of 20 and 10 
in a million). Neither of these facilities have SAN production 
operations that contribute greater than 50 percent to the facility-wide 
risks.
    The facility-wide maximum individual chronic noncancer TOSHI is 
estimated to be 2, based on actual emissions. Of the 2 facilities 
included in this analysis, only one facility has a facility-wide 
maximum chronic noncancer TOSHI value greater than 1 (TOSHI of 2).
c. What is our proposed decision regarding risk acceptability?
    As noted in section III.C of this preamble, we weigh all health 
risk factors in our risk acceptability determination, including the 
MIR; the number of persons in various cancer and noncancer risk ranges; 
cancer incidence; the maximum noncancer HI; the maximum acute noncancer 
HQ; the extent of noncancer risks; the potential for adverse 
environmental effects; distribution of cancer and noncancer risks in 
the exposed population; and risk estimation uncertainty (54 FR 38044, 
September 14, 1989).
    For the SAN source category, the risk analysis we performed 
indicates that the cancer risks to the individual most exposed could be 
up to 0.03-in-1 million due to both actual and allowable emissions. 
This value is less than 1-in-1 million. The risk analysis also shows 
low cancer incidence (1 in every 166,666 years), no potential for human 
health multipathway effects and that chronic noncancer and acute health 
effects are unlikely.
    Our additional analysis of facility-wide risks showed that the 
maximum facility-wide cancer risk is 20-in-1 million. The maximum 
chronic noncancer TOSHI is estimated to be 2, but the source category 
contributes less than 1 percent to the maximum facility-wide TOSHI.
    The EPA has weighed the various health risk measures and health 
factors, including risk estimation uncertainty, discussed above and in 
section III.B.7 of this preamble, and we are proposing that the risks 
from the SAN source category are acceptable.
d. What is our proposed decision regarding ample margin of safety?
    The SAN source category emits HAP which are known, probable or 
possible carcinogens. The EPA evaluated the emissions of these HAP and 
determined that the cancer risks to the individual most exposed are 
less than 1-in-1 million. 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 SAN source 
category would result in a chronic noncancer TOSHI less than 1 and an 
acute HQ less than 1 for the individual most exposed. The EPA undertook 
further analysis to assess whether environmental effects might result 
from

[[Page 1290]]

emissions from this source category. We assume that human toxicity 
values for the inhalation pathway are generally protective of 
terrestrial mammals and plants, and thus, we do not anticipate that 
actual or MACT allowable emissions would result in acute or chronic 
noncancer health effects to these mammals. While we believe this to be 
generally true, we acknowledge that there is some associated 
uncertainty with this assumption. In addition, this source category had 
no reported emissions of PB-HAP and, therefore, no potential for an 
adverse environment effect via multipathway exposures was identified as 
a result of PB-HAP.
    The EPA has weighed the various health risk measures and health 
factors, including risk estimation uncertainty, discussed above and in 
section III.B.7 of this preamble, and we are proposing that the 
existing MACT standards for the SAN source category provide an ample 
margin of safety to protect public health and prevent an adverse 
environmental effect.
2. What are the results of the technology review?
    The results of the technology review for the Group IV Polymers and 
Resins MACT standards are discussed above in section IV.A.2. We 
identified no advancements in practices, processes, and control 
technologies applicable to the emission sources in the Group IV 
Polymers and Resins source categories in our technology review.
3. What other actions are we proposing?
a. SSM Provisions
    The proposed changes to the SSM provisions for the Group IV 
Polymers and Resins MACT standards, which apply to the SAN source 
category, are discussed above in section IV.A.3.a.
b. Electronic Reporting
    The proposed addition of electronic reporting requirements for 
performance tests for the Group IV Polymers and Resins MACT standards, 
which apply to the SAN source category, is discussed above in section 
IV.A.3.b.

C. Methyl Methacrylate Butadiene Styrene Resin (MBS)

1. What are the results of the risk assessments?
a. Inhalation Risk Assessment Results
    Table 7 provides an overall summary of the inhalation risk 
assessment results for the source category.

                                                     Table 7--MBS Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                              Maximum individual cancer risk                                      Maximum chronic noncancer TOSHI
                                    (in 1 million) \2\          Population at    Annual cancer                  \3\                   Maximum off-site
 Number of  facilities \1\  ----------------------------------  risk >= 1-in-1     incidence    ----------------------------------   acute noncancer HQ
                                  Actual         Allowable         million         (cases per         Actual         Allowable              \4\
                             emissions level  emissions level                        year)       emissions level  emissions level
--------------------------------------------------------------------------------------------------------------------------------------------------------
2..........................             0.4              0.4                0          0.00003            0.007            0.007   HQERPG-1 = 9 ethyl
                                                                                                                                    acrylate.
                                                                                                                                   HQAEGL-1 = 0.01 ethyl
                                                                                                                                    acrylate.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the MBS source category is the reproductive system.
\4\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of 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 this source category, the maximum acute values were based on the ERPG-1 HQ for ethyl acrylate, and no REL value
  was available for this HAP. See section III.B.3 of this preamble for explanation of acute dose-response values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table 7, the results of the inhalation risk 
assessment indicated the maximum lifetime individual cancer risk could 
be up to 0.4-in-1 million, the maximum chronic noncancer TOSHI value 
could up to 0.007 and the maximum off-facility site acute HQ value 
could be up to 9, based on the actual emissions level and the ERPG-1 
value for ethyl acrylate. The total estimated national cancer incidence 
from these facilities, based on actual emission levels is 0.00003 
excess cancer cases per year or one case in every 33,333 years.
    Based on our analysis, we believe that actual emissions approximate 
emissions allowable under the MACT standards. Therefore, the risk 
results for MACT-allowable emissions are approximately equal to those 
for actual emissions. For more detail about this estimate of the ratio 
of actual to MACT-allowable emissions and the estimation of MACT-
allowable emission levels and associated risks and impacts, see the 
memorandum, MACT Allowable Emissions and Risks for the Pesticide Active 
Ingredient, Polyether Polyols, and Polymers and Resins IV Production 
Source Categories, in the docket for this rulemaking.
    There were no reported emissions of PB-HAP; therefore, we do not 
expect potential for human health multipathway risks or adverse 
environmental impacts as a result of PB-HAP.
b. Facility-Wide Risk Assessment Results
    Table 8 displays the results of the facility-wide risk assessment. 
This assessment was conducted based on actual emission levels. For 
detailed facility-specific results, see Appendix 4 of the Draft 
Residual Risk Assessment for 7 Source Categories in the docket for this 
rulemaking.

           Table 8--MBS Facility-Wide Risk Assessment Results
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Number of facilities analyzed................................          2
Cancer Risk:
  Estimated maximum facility-wide individual cancer risk (in           2
   1 million)................................................
    Number of facilities with estimated facility-wide                  0
     individual cancer risk of 100-in-1 million or more......
    Number of facilities at which the MBS source category              0
     contributes 50 percent or more to the facility-wide
     individual cancer risks of 100-in-1 million or more.....

[[Page 1291]]

 
    Number of facilities at which the MBS source category              0
     contributes 50 percent or more to the facility-wide
     individual cancer risk of 1-in-1 million or more........
Chronic Noncancer Risk:
    Maximum facility-wide chronic noncancer TOSHI............        < 1
    Number of facilities with facility-wide maximum noncancer          0
     TOSHI greater than 1....................................
    Number of facilities at which the MBS source category              0
     contributes 50 percent or more to the facility-wide
     maximum noncancer TOSHI of 1 or more....................
------------------------------------------------------------------------

    The facility-wide MIR from all HAP emissions at a facility that 
contains sources subject to the Group IV Polymers and Resins MACT 
standards for MBS resins is estimated to be 2-in-1 million, based on 
actual emissions. Of the 2 facilities included in this analysis, none 
have a facility-wide MIR of 100-in-1 million. There is 1 facility with 
a facility-wide MIR of 1-in-1 million or greater (MIR of 2 in a 
million). The facility with an MIR greater than 1-in-1 million does not 
have MBS production operations that contribute greater than 50 percent 
to the facility-wide risks.
    The facility-wide maximum individual chronic noncancer TOSHI is 
estimated to be less than 1, based on actual emissions. Of the 2 
facilities included in this analysis, neither have facility-wide 
maximum chronic noncancer TOSHI values greater than 1.
c. What is our proposed decision regarding risk acceptability?
    As noted in section III.C of this preamble, we weigh all health 
risk factors in our risk acceptability determination, including the 
MIR; the number of persons in various cancer and noncancer risk ranges; 
cancer incidence; the maximum noncancer HI; the maximum acute noncancer 
HQ; the extent of noncancer risks; the potential for adverse 
environmental effects; distribution of cancer and noncancer risks in 
the exposed population; and risk estimation uncertainty (54 FR 38044, 
September 14, 1989).
    For the MBS source category, the risk analysis we performed 
indicates that the cancer risks to the individual most exposed could be 
up to 0.4-in-1 million due to both actual and allowable emissions. This 
value is less than 1-in-1 million. The risk analysis also shows low 
cancer incidence (1 in every 33,333 years), no potential for human 
health multipathway effects and that chronic noncancer health impacts 
are unlikely.
    We estimate that the worst-case acute HQ value could exceed a value 
of 1 for one HAP, ethyl acrylate, with a potential maximum HQ up to 9 
based on the acute ERPG-1 dose-response value. One of the two 
facilities in this source category had an estimated HQ greater than 1 
(ERPG-1 of 9 for ethyl acrylate). All other facilities modeled had an 
HQ less than 1. The maximum HQ based on an AEGL-1 dose-response value 
is 0.01 for ethyl acrylate. For ethyl acrylate, the ERPG-1 value is 
indicative of the odor recognition threshold, while the AEGL-1 value is 
indicative of a level which could result in eye irritation. This 
suggests that, at this worst-case exposure level, a person might smell 
the pollutant, but not experience any eye irritation. As described 
earlier in this preamble, the acute assessment includes some 
conservative assumptions and some uncertainties. Considering the 
improbable assumption that worst-case meteorological conditions are 
present at the same time that maximum hourly emissions of ethyl 
acrylate exceed the average hourly emission rate by a factor of 10 at 
all emission points simultaneously, coincident with individuals being 
in the location of maximum impact and considering the low acute HQ 
value based on the AEGL-1 dose-response value collectively with the 
ERPG-1 value, we believe it is unlikely that HAP emissions from this 
source category would result in acute health effects.
    Our additional analysis of facility-wide risks showed that the 
maximum facility-wide cancer risk is 2-in-1 million and that the 
maximum chronic exposures are expected to be without appreciable risk 
of adverse noncancer health effects.
    The EPA has weighed the various health risk measures and health 
factors, including risk estimation uncertainty, discussed above and in 
section III.B.7 of this preamble, and we are proposing that the risks 
from the MBS source category are acceptable.
d. What is our proposed decision regarding ample margin of safety?
    The MBS source category emits HAP which are known, probable or 
possible carcinogens. The EPA evaluated the emissions of these HAP and 
determined that the cancer risks to the individual most exposed are 
less than 1-in-1 million. 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 MBS source 
category would result in a chronic noncancer TOSHI less than 1 for the 
individual most exposed. While the assessment for acute impacts 
suggests that short-term ethyl acrylate concentrations at one facility 
could exceed the ERPG-1 dose-response value, we believe it unlikely 
that acute impacts would occur due to the conservative assumptions and 
uncertainties associated with the acute analysis. These assumptions 
include having worst-case meteorological conditions present at the same 
time that maximum hourly emissions of ethyl acrylate exceed the average 
hourly emission rate by a factor of 10, coincident with individuals 
being in the location of maximum impact. The EPA undertook further 
analysis to assess whether environmental effects might result from 
emissions from this source category. We assume that human toxicity 
values for the inhalation pathway are generally protective of 
terrestrial mammals and plants and, thus, we do not anticipate that 
actual or MACT allowable emissions would result in acute or chronic 
noncancer health effects to these mammals. While we believe this to be 
generally true, we acknowledge that there is some associated 
uncertainty with this assumption. In addition, this source category had 
no reported emissions of PB-HAP and, therefore, no potential for an 
adverse environmental effect via multipathway exposures was identified.
    The EPA has weighed the various health risk measures and health 
factors, including risk estimation uncertainty, discussed above and in 
section III.B.7 of this preamble, and we are proposing that the 
existing MACT standards for the MBS source category provide an ample 
margin of safety to protect public health and prevent an adverse 
environmental effect.
2. What are the results of the technology review?
    The results of the technology review for the Group IV Polymers and 
Resins MACT standards are discussed above in section IV.A.2. We 
identified no advancements in practices, processes

[[Page 1292]]

and control technologies applicable to the emission sources in the 
Group IV Polymers and Resins source categories in our technology 
review.
3. What other actions are we proposing?
a. SSM Provisions
    The proposed changes to the SSM provisions for the Group IV 
Polymers and Resins MACT standards, which apply to the MBS source 
category, are discussed above in section IV.A.3.a.
b. Electronic Reporting
    The proposed addition of electronic reporting requirements for 
performance tests for the Group IV Polymers and Resins MACT standards, 
which apply to the MBS source category, are discussed above in section 
IV.A.3.b.

D. Polystyrene Resin

1. What are the results of the risk assessments?
a. Inhalation Risk Assessment Results
    Table 9 provides an overall summary of the inhalation risk 
assessment results for the source category.

                                             Table 9--Polystyrene Resins Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                Maximum individual cancer risk                                     Maximum chronic noncancer
                                       (in 1 million) \2\                        Annual cancer             TOSHI \3\
                               --------------------------------  Population at     incidence   --------------------------------  Maximum off-site acute
   Number of  facilities \1\        Actual         Allowable    risk >= 1-in-1    (cases per        Actual         Allowable        noncancer HQ \4\
                                   emissions       emissions        million          year)         emissions       emissions
                                     level           level                                           level           level
--------------------------------------------------------------------------------------------------------------------------------------------------------
11............................               2               2             180         0.00003           0.004           0.004  HQREL = 0.3 styrene.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the polystyrene resin source category is the nervous system.
\4\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of 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 dose-response value. See section III.B.3 of this preamble for explanation of acute dose-response values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table 9, the results of the inhalation risk 
assessment indicated the maximum lifetime individual cancer risk could 
be up to 2-in-1 million, the maximum chronic noncancer TOSHI value 
could be up to 0.004, and the maximum off-facility site acute HQ value 
could be up to 0.3, based on the actual emissions level and the REL 
value for styrene. The total estimated national cancer incidence from 
these facilities, based on actual emission levels, is 0.00003 excess 
cancer cases per year, or one case in every 33,333 years.
    Based on our analysis, we believe that actual emissions approximate 
emissions allowable under the MACT standards. Therefore, the risk 
results for MACT-allowable emissions are approximately equal to those 
for actual emissions. For more detail about this estimate of the ratio 
of actual to MACT-allowable emissions and the estimation of MACT-
allowable emission levels and associated risks and impacts, see the 
memorandum, MACT Allowable Emissions and Risks for the Pesticide Active 
Ingredient, Polyether Polyols, and Polymers and Resins IV Production 
Source Categories, in the docket for this rulemaking.
    There were no reported emissions of PB-HAP; therefore, we do not 
expect potential for human health multipathway risks or adverse 
environmental impacts as a result of PB-HAP.
b. Facility-Wide Risk Assessment Results
    Table 10 displays the results of the facility-wide risk assessment. 
This assessment was conducted based on actual emission levels. For 
detailed facility-specific results, see Appendix 4 of the Draft 
Residual Risk Assessment for 7 Source Categories in the docket for this 
rulemaking.

   Table 10--Polystyrene Resins Facility-Wide Risk Assessment Results
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Number of facilities analyzed................................         11
Cancer Risk:
    Estimated maximum facility-wide individual cancer risk            10
     (in 1 million)..........................................
    Number of facilities with estimated facility-wide                  0
     individual cancer risk of 100-in-1 million or more......
    Number of facilities at which the polystyrene resin                0
     source category contributes 50 percent or more to the
     facility-wide individual cancer risks of 100-in-1
     million or more.........................................
    Number of facilities at which the polystyrene resin                1
     source category contributes 50 percent or more to the
     facility-wide individual cancer risk of 1-in-1 million
     or more.................................................
Chronic Noncancer Risk:
    Maximum facility-wide chronic noncancer TOSHI............         <1
    Number of facilities with facility-wide maximum noncancer          0
     TOSHI greater than 1....................................
    Number of facilities at which the Polystyrene Resin                0
     source category contributes 50 percent or more to the
     facility-wide maximum noncancer TOSHI of 1 or more......
------------------------------------------------------------------------

    The facility-wide MIR from all HAP emissions at a facility that 
contains sources subject to the Group IV Polymers and Resins MACT 
standards for polystyrene resins is estimated to be 10-in-1 million, 
based on actual emissions. Of the 11 facilities included in this 
analysis, none have a facility-wide MIR of 100-in-1 million. There are 
2 facilities with facility-wide MIR of 1-in-1 million or greater (MIR 
of 10 and 2 in a million). One of these facilities has polystyrene 
resin production operations that contribute greater than 50 percent to 
the facility-wide risks.
    The facility-wide maximum individual chronic noncancer TOSHI is 
estimated to be less than 1, based on

[[Page 1293]]

actual emissions. Of the 11 facilities included in this analysis, none 
have facility-wide maximum chronic noncancer TOSHI values greater than 
1.
c. What is our proposed decision regarding risk acceptability?
    As noted in section III.C of this preamble, we weigh all health 
risk factors in our risk acceptability determination, including the 
MIR; the number of persons in various cancer and noncancer risk ranges; 
cancer incidence; the maximum noncancer HI; the maximum acute noncancer 
HQ; the extent of noncancer risks; the potential for adverse 
environmental effects; distribution of cancer and noncancer risks in 
the exposed population; and risk estimation uncertainty (54 FR 38044, 
September 14, 1989).
    For the Polystyrene Resin source category, the risk analysis we 
performed indicates that the cancer risks to the individual most 
exposed could be up to 2-in-1 million due to both actual and allowable 
emissions. This value is considerably less than 100-in-1 million, which 
is the presumptive level of acceptability. The risk analysis also shows 
low cancer incidence (1 in every 33,333 years), no potential for human 
health multipathway effects and that acute and chronic noncancer health 
impacts are unlikely.
    Our additional analysis of facility-wide risks showed that the 
maximum facility-wide cancer risk is 10-in-1 million and that the 
maximum chronic exposures are expected to be without appreciable risk 
of adverse noncancer health effects.
    The EPA has weighed the various health risk measures and health 
factors, including risk estimation uncertainty, discussed above and in 
section III.B.7 of this preamble, and we are proposing that the risks 
from the Polystyrene Resin source category are acceptable.
d. What is our proposed decision regarding ample margin of safety?
    We considered whether the MACT standards provide an ample margin of 
safety to protect public health. In this analysis, we investigated 
available emissions control options that might reduce the risk 
associated with emissions from the source category and considered this 
information along with all of the health risks and other health 
information considered in the risk acceptability determination.
    For the Polystyrene Resin source category, we identified only one 
control option to further address risks from equipment leaks, which 
were shown to contribute 100 percent to 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 
approximately 5 tpy from the baseline actual emissions level. We 
estimated that achieving these reductions would involve a capital cost 
of approximately $9,000,000, a total annualized cost of about 
$1,300,000 and a cost effectiveness of $244,000 per ton of HAP 
emissions reduced. The additional control requirement would achieve 
approximately 20-percent reduction in baseline risks at a very high 
cost. We estimate that the MACT allowable emissions from this source 
category are approximately equal to the reported, actual emissions. 
Therefore, the estimated emission reduction, risk reduction and costs 
discussed above would also be applicable to the MACT allowable 
emissions level. We believe that the costs of this option are not 
reasonable, given the level of emission and risk reduction.
    In accordance with the approach established in the Benzene NESHAP, 
the EPA weighed all health risk measures and information considered in 
the risk acceptability determination, along with the costs and economic 
impacts of emissions controls, technological feasibility, uncertainties 
and other relevant factors in making our ample margin of safety 
determination. Considering the health risk information and the 
unreasonable cost effectiveness of the option identified, we propose 
that the existing MACT standards provide an ample margin of safety to 
protect public health and prevent an adverse environmental effect.
2. What are the results of the technology review?
    The results of the technology review for the Group IV Polymers and 
Resins MACT standards are discussed above in section IV.A.2. We 
identified no advancements in practices, processes and control 
technologies applicable to the emission sources in the Group IV 
Polymers and Resins source categories in our technology review.
3. What other actions are we proposing?
a. SSM Provisions
    The proposed changes to the SSM provisions for the Group IV 
Polymers and Resins MACT standards, which apply to the polystyrene 
resin source category, are discussed above in section IV.A.3.a.
b. Electronic Reporting
    The proposed addition of electronic reporting requirements for 
performance tests for the Group IV Polymers and Resins MACT standards, 
which apply to the polystyrene resin source category, are discussed 
above in section IV.A.3.b.

E. Poly (Ethylene Terephthalate) Resin (PET)

1. What are the results of our analyses and proposed decisions 
regarding unregulated HAP and/or emissions sources?
a. Equipment Leaks
    We identified the absence of a limit for a potentially significant 
emissions source within the provisions of the Group IV Polymers and 
Resins MACT standards that apply to the PET continuous TPA high 
viscosity multiple end finisher subcategory. Specifically, there are no 
regulations for equipment leaks for this source subcategory.\22\ As 
these processes are potentially major sources of emissions for the one 
facility in the source category, we are proposing to set a work 
practice standard for equipment leaks under CAA section 112(d)(2) and 
(d)(3) in this action. CAA section 112(h)(1) states that the 
Administrator may prescribe a work practice standard or other 
requirements, consistent with the provisions of CAA sections 112(d) or 
(f), in those cases where, in the judgment of the Administrator, it is 
not feasible to enforce an emission standard. CAA section 112(h)(2) 
defines the phrase ``not feasible to prescribe or enforce an emission 
standard'' as follows:
---------------------------------------------------------------------------

    \22\ Note that these uncontrolled emissions were included in the 
risk assessment for the PET source category.

    [A]ny situation in which the Administrator determines that (A) a 
hazardous air pollutant or pollutants cannot be emitted through a 
conveyance designed and constructed to emit or capture such 
pollutant, or that any requirement for, or use of, such a conveyance 
would be inconsistent with any Federal, State, or local law, or (B) 
the application of measurement methodology to a particular class of 
sources is not practicable due to technological and economic 
---------------------------------------------------------------------------
limitations.

    The work practice standards in this proposed rule are consistent 
with CAA section 112(h)(2)(B), because applying a measurement 
methodology to this class of sources is not technologically and 
economically feasible due to the number of openings and possible 
emissions points and because the fugitive emissions cannot be routed to 
a conveyance designed to capture such emissions.
    As there is only one facility in the source subcategory, the 
emissions level currently being achieved by this facility represents 
the MACT floor. However, emissions from equipment leaks are

[[Page 1294]]

intermittent and fugitive in nature and, therefore, it is not feasible 
to fully measure the mass emission rate from numerous potential leaks 
at this facility or to route such emissions through a conveyance 
designed and constructed to emit or capture such fugitive pollutants. 
For this reason, under CAA section 112(h), we are proposing to 
establish the MACT floor for this source subcategory, based on the work 
practices this facility currently performs to limit emissions from 
equipment leaks. The work practices this facility follows are to 
perform a 2- to 3-hour leak check upon startup following an outage 
where changes have been made to the facility's esterification 
equipment, which is the only area of the facility that has equipment in 
gas/vapor service. This is conducted by introducing hot ethylene g1yco1 
vapors into the system. Any leaks identified are repaired by tightening 
flange bolts before introducing new materials into the process. The 
other equipment components at the facility are in vacuum or heavy 
liquid service, which are not monitored due to the low vapor pressure 
of predominant HAP, ethylene glycol and the low potential for equipment 
leak emissions from these components.
    As part of our beyond-the-floor analysis, we considered 
alternatives more stringent than the MACT floor option. We identified 
the HON LDAR program as one such option, which is the required level of 
control for other facilities subject to the Group IV Polymers and 
Resins MACT standards. The HON requires the use of sensory monitoring 
for pumps, valves, agitators and connectors in heavy liquid service; 
the use of EPA Method 21 of 40 CFR part 60, Appendix A, for instrument 
monitoring of equipment in gas/vapor service; and equipment in vacuum 
service is not required to be monitored. Based on previous information 
prepared to examine the equipment leak costs for facilities in the PET 
source category,\23\ the capital costs of this option are estimated to 
be approximately $13,000 and the total annual costs are estimated to be 
approximately $13,000. The estimated HAP decrease is 1.27 tpy, with a 
cost effectiveness of approximately $11,000/ton. Table 11 summarizes 
the cost and emission reduction impacts of the proposed options. 
Because the HAP reduced would be ethylene glycol, which does not 
contribute to the cancer risk estimate for the PET source category, the 
MIR for the source category would remain at 9. Any impact on the 
magnitude of the HI resulting from ethylene glycol emission reductions 
due to this control option would be negligible as ethylene glycol 
contributes minimally to the chronic noncancer TOSHI of 0.5. These risk 
values are discussed further in section IV.E.2 below.
---------------------------------------------------------------------------

    \23\ Memorandum to Group IV Resins Docket, A-92-45, from Ken 
Meardon, Pacific Environmental Services, Inc. Re-Evaluation of 
Equipment Leak Emissions and Costs at PET Facilities.

                   Table 11--PET Continuous TPA High Viscosity Equipment Leaks Options Impacts
----------------------------------------------------------------------------------------------------------------
                                                                                                      Cost
                                            HAP emissions     Capital cost                        effectiveness
         Regulatory alternatives                (tpy)              ($)        Annual cost  ($)     ($/ton HAP
                                                                                                    removed)
----------------------------------------------------------------------------------------------------------------
Baseline................................              1.43              ----              ----              ----
1 (MACT floor)..........................              1.43                 0                 0              ----
2 (Beyond-the-floor)....................              0.16            13,000            13,000            11,000
----------------------------------------------------------------------------------------------------------------

    We believe that the costs of this beyond-the-floor option are not 
reasonable, given the level of emission reduction. Therefore, we are 
proposing an emission standard that reflects the MACT floor option, 
which is a work practice standard.
    We are requesting comment on this analysis and these options.
b. Changes to PCCT Provisions in Response to a Petition for 
Reconsideration
    We identified a potentially significant emissions source that is 
currently effectively unregulated within the provisions of the Group IV 
Polymers and Resins MACT standards that apply to the sources producing 
PET using the continuous TPA high viscosity multiple end finisher 
process. Specifically, sources have not been required to comply with 
the previously promulgated provisions addressing emissions from PCCT 
within this source subcategory. We originally promulgated standards for 
PCCT in this subcategory in the September 12, 1996, Federal Register 
publication of NESHAP for Group IV Polymer and Resin source categories. 
On August 29, 2000, the EPA took action to indefinitely stay the 
compliance date for the PCCT provisions for this subcategory because 
the EPA was in the process of responding to a request to reconsider 
portions of the Group IV Polymers and Resins MACT standards that could 
result in changes to the emission limitation for PCCT in this 
subcategory (65 FR 52319-23). As PCCT are potentially major sources of 
emissions for the one facility in the PET continuous TPA high viscosity 
multiple end finisher subcategory, we have reconsidered the emissions 
and cost data available and we are proposing MACT standards for PCCT 
under CAA section 112(d)(2) and (d)(3) in this action.
    As there is only one facility in the source subcategory, the 
emissions level currently being achieved by this facility represents 
the MACT floor. The facility is currently regulated by the Polymers 
Manufacturing New Source Performance Standards, which requires the 
facility to maintain an ethylene glycol concentration in the PCCT at or 
below 6.0 percent by weight, averaged on a daily basis over a rolling 
14-day period of operating days. We are proposing to establish the MACT 
floor for this source subcategory, based on the 6.0 percent by weight 
ethylene glycol concentration limit this facility is required to 
achieve.
    As part of our beyond-the-floor analysis, we considered 
alternatives more stringent than the MACT floor option. The original 
PCCT regulations promulgated in the Group IV Polymer and Resin NESHAP 
established an ethylene glycol concentration limit of 4.0 percent by 
weight for PCCT in this source subcategory, based on the information 
available on controls and costs, but the source has never been required 
to achieve this limit, in light of our August 29, 2000, indefinite stay 
of the compliance date. We identified this 4.0-percent concentration 
limit as a beyond-the-floor option for our revised analysis. To achieve 
the beyond-the-floor option, the facility would need to modify its 
existing ethylene glycol

[[Page 1295]]

recovery system and increase the amount of steam used to strip ethylene 
glycol from the contaminated water. Based on information received from 
the only facility in the subcategory after promulgation of the Group IV 
Polymers and Resins MACT standards, the capital costs of this option 
are estimated to be approximately $8.7 million and the total annual 
costs are estimated to be approximately $4.2 million. The estimated HAP 
decrease is 49.0 tpy, with a cost effectiveness of approximately 
$86,000/ton. Table 12 summarizes the cost and emission reduction 
impacts of the proposed options. Because the HAP reduced would be 
ethylene glycol, which does not contribute to the cancer risk estimate 
for the PET source category, the MIR for the source category would 
remain at 9. Any impact on the magnitude of the HI resulting from 
ethylene glycol emission reductions due to this control option would be 
negligible as ethylene glycol contributes minimally to the chronic 
noncancer TOSHI of 0.5. These risk values are discussed further in 
section IV.E.2 below. Further information regarding this analysis can 
be found in the memorandum, Impacts Assessment for Process Contact 
Cooling Towers for the PET Continuous TPA High Viscosity Multiple End 
Finisher Subcategory, available in the docket for this action.

  Table 12--PET Continuous TPA High Viscosity Multiple End Finisher Subcategory Process Contact Cooling Towers
                                                 Options Impacts
----------------------------------------------------------------------------------------------------------------
                                                                                                      Cost
                                            HAP emissions     Capital cost                        effectiveness
         Regulatory alternatives                (tpy)              ($)        Annual cost  ($)     ($/ton HAP
                                                                                                    removed)
----------------------------------------------------------------------------------------------------------------
Baseline................................             147.0              ----              ----              ----
1 (MACT floor)..........................             147.0                 0                 0              ----
2 (Beyond-the-floor)....................              98.0         8,800,000         4,200,000            86,000
----------------------------------------------------------------------------------------------------------------

    We believe that the costs of this beyond-the-floor option are not 
reasonable, given the level of emission reduction. Therefore, we are 
proposing to re-set the previously stayed MACT standard as an emission 
standard that reflects the MACT floor option, which is the ethylene 
glycol concentration limit of 6.0 weight percent.
    We are requesting comment on this analysis and these options.
2. What are the results of the risk assessments?
a. Inhalation Risk Assessment Results
    Table 13 provides an overall summary of the inhalation risk 
assessment results for the source category.

                                                    Table 13--PET Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                Maximum individual cancer risk                                     Maximum chronic noncancer
                                      (in 1 million) \2\                         Annual cancer             TOSHI \3\
                               --------------------------------  Population at     incidence   --------------------------------  Maximum off-site  acute
   Number of  facilities \1\        Actual         Allowable    risk >=  1-in-    (cases per        Actual         Allowable        noncancer  HQ \4\
                                   emissions       emissions       1 million         year)         emissions       emissions
                                     level           level                                           level           level
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                HQREL = 8
                                                                                                                                acetaldehyde.
15............................               9               9           4,200           0.002             0.5             0.5  HQERPG-1 = 1
                                                                                                                                 acetaldehyde.
                                                                                                                                HQAEGL-1 = 0.2
                                                                                                                                 acetaldehyde.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the PET source category is the respiratory system.
\4\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of 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 dose-response value. See section III.B.3 of this preamble for explanation of acute dose-response values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table 13, the results of the inhalation risk 
assessment indicated the maximum lifetime individual cancer risk could 
be up to 9-in-1 million, the maximum chronic noncancer TOSHI value 
could be up to 0.5, and the maximum off-facility site acute HQ value 
could be up to 8, based on the actual emissions level and the REL value 
for acetaldehyde. The total estimated national cancer incidence from 
these facilities based on actual emission levels is 0.002 excess cancer 
cases per year or one case in every 500 years.
    Based on our analysis, we believe that actual emissions approximate 
emissions allowable under the MACT standards. Therefore, the risk 
results for MACT-allowable emissions are approximately equal to those 
for actual emissions. For more detail about this estimate of the ratio 
of actual to MACT-allowable emissions and the estimation of MACT-
allowable emission levels and associated risks and impacts, see the 
memorandum, MACT Allowable Emissions and Risks for the Pesticide Active 
Ingredient, Polyether Polyols, and Polymers and Resins IV Production 
Source Categories, in the docket for this rulemaking.
    One facility reported emissions of PB-HAP, including cadmium 
compounds, lead compounds and POM. Therefore, we compared the facility-
specific

[[Page 1296]]

emission rates of each of these PB-HAP to the TRIM-Screen emission 
threshold values to assess the potential for significant human health 
risks or environmental risks via non-inhalation pathways. The emission 
rates were less than the emission threshold values; therefore, we do 
not expect potential for human health multipathway risks or adverse 
environmental impacts as a result of PB-HAP.
b. Facility-Wide Risk Assessment Results
    Table 14 displays the results of the facility-wide risk assessment. 
This assessment was conducted based on actual emission levels. For 
detailed facility-specific results, see Appendix 4 of the Draft 
Residual Risk Assessment for 7 Source Categories in the docket for this 
rulemaking.

           Table 14--PET Facility-Wide Risk Assessment Results
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Number of facilities analyzed................................         15
Cancer Risk:
    Estimated maximum facility-wide individual cancer risk             9
     (in 1 million)..........................................
    Number of facilities with estimated facility-wide                  0
     individual cancer risk of 100-in-1 million or more......
    Number of facilities at which the PET source category              0
     contributes 50 percent or more to the facility-wide
     individual cancer risks of 100-in-1 million or more.....
    Number of facilities at which the PET source category              6
     contributes 50 percent or more to the facility-wide
     individual cancer risk of 1-in-1 million or more........
Chronic Noncancer Risk:
    Maximum facility-wide chronic noncancer TOSHI............          1
    Number of facilities with facility-wide maximum noncancer          1
     TOSHI greater than 1....................................
    Number of facilities at which the PET source category              0
     contributes 50 percent or more to the facility-wide
     maximum noncancer TOSHI of 1 or more....................
------------------------------------------------------------------------

    The facility-wide MIR from all HAP emissions at a facility that 
contains sources subject to the Group IV Polymers and Resins MACT 
standards for PET is estimated to be 9-in-1 million, based on actual 
emissions. Of the 15 facilities included in this analysis, none have a 
facility-wide MIR of 100-in-1 million. There are 8 facilities with 
facility-wide MIR of 1-in-1 million or greater (MIR ranging from 2 to 9 
in a million). Six of these facilities have PET production operations 
that contribute greater than 50 percent to the facility-wide risks.
    The facility-wide maximum individual chronic noncancer TOSHI is 
estimated to be 1, based on actual emissions. Of the 15 facilities 
included in this analysis, one has a facility-wide maximum chronic 
noncancer TOSHI value of 1.
c. What is our proposed decision regarding risk acceptability?
    As noted in section III.C of this preamble, we weigh all health 
risk factors in our risk acceptability determination, including the 
MIR; the number of persons in various cancer and noncancer risk ranges; 
cancer incidence; the maximum noncancer HI; the maximum acute noncancer 
HQ; the extent of noncancer risks; the potential for adverse 
environmental effects; distribution of cancer and noncancer risks in 
the exposed population; and risk estimation uncertainty (54 FR 38044, 
September 14, 1989).
    For the PET source category, the risk analysis we performed 
indicates that the cancer risks to the individual most exposed could be 
up to 9-in-1 million due to both actual and allowable emissions. This 
value is considerably less than 100-in-1 million, which is the 
presumptive level of acceptability. The risk analysis also shows low 
cancer incidence (1 in every 500 years), no potential for human health 
multipathway effects and that chronic noncancer health impacts are 
unlikely.
    We estimate that the worst-case acute HQ value could exceed a value 
of 1 for one HAP, acetaldehyde, with a potential maximum HQ up to 8 
based on the acute REL dose-response value. Seven of the 15 facilities 
in this source category had an estimated acute HQ greater than 1 (REL 
for acetaldehyde ranging from 3 to 8). All other facilities modeled had 
an acute HQ less than 1. The maximum acute HQs based on ERPG-1 and 
AEGL-1 dose-response values for acetaldehyde are 1 and 0.2, 
respectively. As described earlier in this preamble, the acute 
assessment includes some conservative assumptions and some 
uncertainties. Considering the improbable assumption that worst-case 
meteorological conditions are present at the same time that maximum 
hourly emissions of acetaldehyde exceed the average hourly emission 
rate by a factor of 10 at all emission points simultaneously, 
coincident with individuals being in the location of maximum impact and 
considering the low acute HQ values, based on the ERPG-1 and AEGL-1 
dose-response values collectively with the REL value, we believe it is 
unlikely that HAP emissions from this source category would result in 
acute health effects.
    Our screening level evaluation of the potential health risks 
associated with emissions of PB-HAP did not indicate potential for 
adverse multipathway impacts due to emissions of the any of the PB-HAP 
associated with the source category.
    Our additional analysis of facility-wide risks showed that the 
maximum facility-wide cancer risk is 9-in-1 million. The maximum 
chronic noncancer TOSHI is estimated to be 1, but the source category 
contributes only 5 percent to the maximum facility-wide TOSHI.
    The EPA has weighed the various health risk measures and health 
factors, including risk estimation uncertainty, discussed above and in 
section III.B.7 of this preamble, and we are proposing that the risks 
from the PET source category are acceptable.
d. What is our proposed decision regarding ample margin of safety?
    We considered whether the MACT standards provide an ample margin of 
safety to protect public health. In this analysis, we investigated 
available emissions control options that might reduce the risk 
associated with emissions from the source category and considered this 
information along with all of the health risks and other health 
information considered in the risk acceptability determination.
    For the PET source category, we identified only one control option 
to further address risks from equipment leaks, which were shown to 
contribute 100 percent to 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

[[Page 1297]]

approximately 123 tpy from the baseline actual emissions level. We 
estimated that achieving these reductions would involve a capital cost 
of approximately $220,000,000, a total annualized cost of about 
$30,000,000 and a cost effectiveness of $244,000 per ton of HAP 
emissions reduced. The additional control requirement would achieve 
approximately 20-percent reduction in baseline risks at a very high 
cost. We estimate that the MACT allowable emissions from this source 
category are approximately equal to the reported, actual emissions. 
Therefore, the estimated emission reduction, risk reduction and costs 
discussed above would also be applicable to the MACT allowable 
emissions level. We believe that the costs of this option are not 
reasonable, given the level of emission and risk reduction.
    In accordance with the approach established in the Benzene NESHAP, 
the EPA weighed all health risk measures and information considered in 
the risk acceptability determination, along with the costs and economic 
impacts of emissions controls, technological feasibility, uncertainties 
and other relevant factors in making our ample margin of safety 
determination. Considering the health risk information and the 
unreasonable cost effectiveness of the option identified, we propose 
that the existing MACT standards provide an ample margin of safety to 
protect public health and prevent an adverse environmental effect.
3. What are the results of the technology review?
    The results of the technology review for the Group IV Polymers and 
Resins MACT standards are discussed above in section IV.A.2. We 
identified no advancements in practices, processes and control 
technologies applicable to the emission sources in the Group IV 
Polymers and Resins source categories in our technology review.
4. What other actions are we proposing?
a. SSM Provisions
    The proposed changes to the SSM provisions for the Group IV 
Polymers and Resins MACT standards, which apply to the PET source 
category, are discussed above in section IV.A.3.a.
b. Electronic Reporting
    The proposed addition of electronic reporting requirements for 
performance tests for the Group IV Polymers and Resins MACT standards, 
which apply to the PET source category, are discussed above in section 
IV.A.3.b.

V. Analytical Results and Proposed Decisions for Pesticide Active 
Ingredient Production

A. What are the results of the risk assessments?

1. Inhalation Risk Assessment Results
    Table 16 provides an overall summary of the inhalation risk 
assessment results for the source category.

                                                    Table 16--PAI Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                Maximum individual cancer risk                                     Maximum chronic noncancer
                                       (in 1 million) \2\                        Annual cancer             TOSHI \3\
                               --------------------------------  Population at     incidence   --------------------------------  Maximum off-site acute
   Number of  facilities \1\        Actual         Allowable    risk >= 1-in-1    (cases per        Actual         Allowable        noncancer HQ \4\
                                   emissions       emissions        million          year)         emissions       emissions
                                     level           level                                           level           level
--------------------------------------------------------------------------------------------------------------------------------------------------------
17............................               7               7          11,000           0.001             0.7               3  HQREL = 8 ethylene
                                                                                                                                 glycol ethyl ether.
                                                                                                                                HQERPG-1 = 0.3 chlorine.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the PAI source category is the respiratory system.
\4\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of 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 dose-response value. See section III.B.3 of this preamble for explanation of acute dose-response values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table 16, the results of the inhalation risk 
assessment indicated the maximum lifetime individual cancer risk could 
be up to 7-in-1 million, the maximum chronic noncancer TOSHI value 
could be up to 0.7, and the maximum off-facility site acute HQ value 
could be up to 8, based on the actual emissions level and the REL value 
for ethylene glycol ethyl ethers. The total estimated national cancer 
incidence from these facilities, based on actual emission levels is 
0.001 excess cancer cases per year or one case in every 1,000 years.
    Based on our analysis, we estimate that the MACT-allowable 
emissions levels from process vents for organic HAP emissions could be 
up to five times the actual emissions and the MACT-allowable level for 
chlorine and HCl emissions could be up to six times the actual 
emissions from this source category. However, the highest cancer risks 
are caused by fugitive emissions and the application of the factor of 
five to the organic HAP emissions from point sources did not result in 
cancer risks in excess of the levels resulting from actual fugitive 
source emissions. Therefore, the cancer risk results for MACT-allowable 
emissions are approximately equal to those for actual emissions. The 
highest TOSHI at the MACT-allowable level is approximately 3. For more 
detail about this estimate of the ratio of actual to MACT-allowable 
emissions and the estimation of MACT-allowable emission levels and 
associated risks and impacts, see the memorandum, MACT Allowable 
Emissions and Risks for the Pesticide Active Ingredient, Polyether 
Polyols, and Polymers and Resins IV Production Source Categories, in 
the docket for this rulemaking.
    Three facilities reported emissions of PB-HAP, including lead 
compounds, PCBs and hexachlorobenzene. We typically would compare the 
facility-specific emission rates of each of these PB-HAP to the TRIM-
Screen emission threshold values to assess the potential for 
significant human health risks or environmental risks via non-
inhalation pathways. However, while lead is a PB-HAP, the National 
Ambient Air Quality Standards (NAAQS) value (which was used for the 
chronic noncancer risk assessment) takes into account air-related 
multipathway exposures, so a

[[Page 1298]]

separate multipathway screening value was not developed here. Since we 
did not estimate any exceedances of the NAAQS in our chronic noncancer 
risk assessment, we do not expect any unacceptable multipathway 
exposure and risk of concern due to lead emissions from these 
facilities. In addition, there is currently not a screening value for 
PCBs or hexachlorobenzene, and they were not evaluated for potential 
non-inhalation risks.
2. Facility-Wide Risk Assessment Results
    Table 17 displays the results of the facility-wide risk assessment. 
This assessment was conducted based on actual emission levels. For 
detailed facility-specific results, see Appendix 4 of the Draft 
Residual Risk Assessment for 7 Source Categories in the docket for this 
rulemaking.

           Table 17--PAI Facility-Wide Risk Assessment Results
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Number of facilities analyzed................................         17
Cancer Risk:
    Estimated maximum facility-wide individual cancer risk            20
     (in 1 million)..........................................
    Number of facilities with estimated facility-wide                  0
     individual cancer risk of 100-in-1 million or more......
    Number of facilities at which the PAI source category              0
     contributes 50 percent or more to the facility-wide
     individual cancer risks of 100-in-1 million or more.....
    Number of facilities at which the PAI source category              4
     contributes 50 percent or more to the facility-wide
     individual cancer risk of 1-in-1 million or more........
Chronic Noncancer Risk:
    Maximum facility-wide chronic noncancer TOSHI............          2
    Number of facilities with facility-wide maximum noncancer          1
     TOSHI greater than 1....................................
    Number of facilities at which the PAI source category              0
     contributes 50 percent or more to the facility-wide
     maximum noncancer TOSHI of 1 or more....................
------------------------------------------------------------------------

    The facility-wide MIR from all HAP emissions at a facility that 
contains sources subject to the PAI MACT standards is estimated to be 
20-in-1 million, based on actual emissions. Of the 17 facilities 
included in this analysis, none have a facility-wide MIR of 100-in-1 
million. There are 12 facilities with facility-wide MIR of 1-in-1 
million or greater (2 facilities with an MIR of 20 in a million and 2 
facilities with an MIR of 10 in a million; the remaining 8 facilities 
have an MIR below 10 in a million). Four of these facilities have PAI 
production operations that contribute greater than 50 percent to the 
facility-wide risks.
    The facility-wide maximum individual chronic noncancer TOSHI is 
estimated to be 2, based on actual emissions. Of the 17 facilities 
included in this analysis, one has a facility-wide maximum chronic 
noncancer TOSHI values greater than 1 (TOSHI of 2).
3. What is our proposed decision regarding risk acceptability?
    As noted in section III.C of this preamble, we weigh all health 
risk factors in our risk acceptability determination, including the 
MIR; the number of persons in various cancer and noncancer risk ranges; 
cancer incidence; the maximum noncancer HI; the maximum acute noncancer 
HQ; the extent of noncancer risks; the potential for adverse 
environmental effects; distribution of cancer and noncancer risks in 
the exposed population; and risk estimation uncertainty (54 FR 38044, 
September 14, 1989).
    For the PAI source category, the risk analysis we performed 
indicates that the cancer risks to the individual most exposed could be 
up to 7-in-1 million due to both actual and allowable emissions. This 
value is considerably less than 100-in-1 million, which is the 
presumptive level of acceptability. The risk analysis also shows low 
cancer incidence (1 in every 1,000 years) and that chronic noncancer 
health impacts are unlikely at the actual emissions levels.
    We estimate that the worst-case acute HQ value could exceed a value 
of 1 for six HAP: ethylene glycol ethyl ethers (one facility); acrolein 
(one facility); chloroform (one facility); nickel compounds (one 
facility); chlorine (one facility); and formaldehyde (one facility). 
One facility had acute HQ greater than 1 for three HAP (ethyl glycol 
ethyl ether, acrolein and nickel). The potential maximum HQ is up to 8, 
based on the acute REL dose-response value for ethylene glycol ethyl 
ether. Four of the 17 facilities in this source category had an 
estimated HQ greater than 1. All other facilities modeled had an HQ 
less than 1. The maximum HQ based on an ERPG-1 or AEGL-1 dose-response 
value is 0.3, based on the AEGL-1 for chlorine. As described earlier in 
this preamble, the acute assessment includes some conservative 
assumptions and some uncertainties. Considering the improbable 
assumption that worst-case meteorological conditions are present at the 
same time that maximum hourly emissions of ethylene glycol ethyl ether 
exceed the average hourly emission rate by a factor of 10 at all 
emission points simultaneously for three of these four facilities or a 
factor of 2 at all emission points simultaneously for the other 
facility, coincident with individuals being in the location of maximum 
impact and considering the low acute HQ values, based on the AEGL-1 and 
ERPG-1 dose-response values collectively with the REL values, we 
believe it is unlikely that HAP emissions from this source category 
would result in acute health effects.
    Our screening level evaluation of the potential health risks 
associated with emissions of PB-HAP did not indicate potential for 
adverse multipathway impacts due to emissions of lead. While there are 
no screening values for PCB and hexachlorobenzene, these HAP are not 
emitted in appreciable quantities and are not expected to cause 
multipathway impacts of concern.
    Our additional analysis of facility-wide risks showed that the 
maximum facility-wide cancer risk is 20-in-1 million. The maximum 
chronic noncancer TOSHI is estimated to be 2, but the source category 
contributes less than 5 percent to the maximum facility-wide TOSHI.
    The EPA has weighed the various health risk measures and health 
factors, including risk estimation uncertainty, discussed above and in 
section III.B.7 of this preamble, and we are proposing that the risks 
from the PAI source category are acceptable.
4. What is our proposed decision regarding ample margin of safety?
    We considered whether the MACT standards provide an ample margin of 
safety to protect public health. In this analysis, we investigated 
available

[[Page 1299]]

emissions control options that might reduce the risk associated with 
emissions from the source category and considered this information 
along with all of the health risks and other health information 
considered in the risk acceptability determination.
    For the PAI source category, we identified only one control option 
to further address risks from equipment leaks, which were shown to 
contribute 100 percent to 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 
approximately 101 tpy from the baseline actual emissions level. We 
estimated that achieving these reductions would involve a capital cost 
of approximately $180,000,000, a total annualized cost of about 
$25,000,000 and a cost effectiveness of $244,000 per ton of HAP 
emissions reduced. The additional control requirement would achieve 
approximately 60-percent reduction in baseline risks at a very high 
cost. We estimate that the MACT allowable emissions from equipment 
leaks at this source category are approximately equal to the reported, 
actual emissions. Therefore, the estimated emission reduction, risk 
reduction and costs discussed above would also be applicable to the 
MACT allowable emissions level. We believe that the costs of this 
option are not reasonable, given the level of emission and risk 
reduction.
    In accordance with the approach established in the Benzene NESHAP, 
the EPA weighed all health risk measures and information considered in 
the risk acceptability determination, along with the costs and economic 
impacts of emissions controls, technological feasibility, uncertainties 
and other relevant factors in making our ample margin of safety 
determination. Considering the health risk information and the 
unreasonable cost effectiveness of the option identified, we propose 
that the existing MACT standards provide an ample margin of safety to 
protect public health and prevent an adverse environmental effect.

B. What are the results of the technology review?

    In the decade since the PAI NESHAP was promulgated, the EPA has 
developed 19 air toxics regulations for source categories that emit 
organic HAP from the same type of emissions sources that are present in 
the PAI source category. We reviewed the regulatory requirements and/or 
technical analyses for these 19 regulations for new practices, 
processes and control technologies. We also conducted a search of the 
RBLC for controls for VOC- and HAP-emitting processes in the 
Agricultural Chemical Manufacturing and the SOCMI categories with 
permits dating back to 1997.
    We identified no advancements in practices, processes and control 
technologies applicable to the emission sources in the PAI source 
category in our technology review.

C. What other actions are we proposing?

1. SSM Provisions
    As we have done in other recent risk and technology rulemakings, we 
are proposing to eliminate the SSM exemption in the PAI MACT standards. 
Consistent with Sierra Club v. EPA, the EPA is proposing that standards 
in this rule would apply at all times. We are proposing several 
revisions to 40 CFR part 63, subpart MMM. Specifically, we are 
proposing to revise Table 1 to indicate that the requirements of 40 CFR 
63.6(e) of the General Provisions do not apply. The 40 CFR 63.6(e) 
requires owner or operators to act according to the general duty to 
``operate and maintain any affected source, including associated air 
pollution control equipment and monitoring equipment, in a manner 
consistent with safety and good air pollution control practices for 
minimizing emissions.'' We are separately proposing to incorporate this 
general duty to minimize into 40 CFR 63.1360(e). The 40 CFR 63.6(e) 
also requires the owner or operator of an affected source to develop a 
written SSM plan. We are proposing to remove the SSM plan requirement. 
We are proposing to remove the explanation of applicability of 
emissions standards during periods SSM in 40 CFR 63.1360(e); remove the 
malfunction plan from 40 CFR 63.1367(a); clarify that representative 
conditions do not include periods of SSM throughout the rule; remove 
references to periods of SSM in monitoring; and revise the SSM-
associated recordkeeping and reporting requirements in 40 CFR 
63.1367(a) to require reporting and recordkeeping for periods of 
malfunction. We are also proposing to revise Table 1 to indicate that 
SSM-related provisions in 40 CFR 63.6(e)(1), 63.6(e)(3), 63.6(f)(1); 40 
CFR 63.7(e)(1); 40 CFR 63.8(c)(1)-(3); 40 CFR 63.10(c)(10), (11), and 
(15); and 40 CFR 63.10(d)(5) of the General Provisions do not apply. We 
are also proposing to add requirements in 40 CFR 63.1363(b)(4) to 
clarify that PRD releases to the atmosphere are violations of the 
emissions standards and to require pressure release alarms and to add 
requirements in 40 CFR 63.1463(h)(4) to require reporting of any 
pressure device releases to the atmosphere with the periodic report. In 
addition, following our recently established practice in other risk and 
technology review rulemakings, we are proposing to promulgate an 
affirmative defense against civil penalties for exceedances of emission 
standards caused by malfunctions, as well as criteria for establishing 
the affirmative defense.
2. Electronic Reporting
    To increase the ease and efficiency of data submittal and improve 
data accessibility, we are proposing to require the submission of 
electronic copies of required performance tests for test methods that 
are supported by the ERT to EPA's WebFIRE database. These provisions 
are added in 40 CFR 63.1368(p).

VI. Analytical Results and Proposed Decisions for Polyether Polyols 
Production

A. What are the results of the risk assessments?

1. Inhalation Risk Assessment Results
    Table 19 provides an overall summary of the inhalation risk 
assessment results for the source category.

[[Page 1300]]

                                                    Table 19--PEPO Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                Maximum individual cancer risk                                     Maximum chronic noncancer
                                       (in 1 million) \2\                        Annual cancer             TOSHI \3\
                               --------------------------------  Population at     incidence   --------------------------------  Maximum off-site acute
   Number of  facilities \1\        Actual         Allowable    risk >= 1-in-1    (cases per        Actual         Allowable        noncancer HQ \4\
                                   emissions       emissions        million          year)         emissions       emissions
                                     level           level                                           level           level
--------------------------------------------------------------------------------------------------------------------------------------------------------
23............................              30              30         160,000            0.02             0.8             0.8  HQREL = 6 glycol ethers.
                                                                                                                                HQAEGL-1 = 0.1 acrolein.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the PEPO source category is the respiratory system.
\4\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of 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 dose-response value. See section III.B.3 of this preamble for explanation of acute dose-response values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table 19, the results of the inhalation risk 
assessment indicated the maximum lifetime individual cancer risk could 
be up to 30-in-1 million, the maximum chronic noncancer TOSHI value 
could be up to 0.8 and the maximum off-facility site acute HQ value 
could be up to 6, based on the actual emissions level and the REL value 
for glycol ethers. The total estimated national cancer incidence from 
these facilities, based on actual emission levels is 0.02 excess cancer 
cases per year or one case in every 50 years.
    Based on our analysis, we estimate that the MACT-allowable 
emissions level for organic non-epoxide HAP emissions from certain 
process vents could be up to five times the actual emissions from this 
source category. However, the highest cancer risks are caused by 
epoxide emissions, and the application of the factor of five to the 
non-epoxide organic HAP emissions from point sources did not result in 
cancer risks in excess of the levels resulting from actual epoxide 
emissions. Therefore, the cancer risk results for MACT-allowable 
emissions are approximately equal to those for actual emissions. For 
more detail about this estimate of the ratio of actual to MACT-
allowable emissions and the estimation of MACT-allowable emission 
levels and associated risks and impacts, see the memorandum, MACT 
Allowable Emissions and Risks for the Pesticide Active Ingredient, 
Polyether Polyols, and Polymers and Resins IV Production Source 
Categories, in the docket for this rulemaking.
    Two facilities reported emissions of PB-HAP, including fluoranthene 
(a POM HAP) and lead compounds. We typically compare the facility-
specific emission rates of PB-HAP to the TRIM-Screen emission threshold 
values to assess the potential for significant human health risks or 
environmental risks via non-inhalation pathways. However, while lead is 
a PB-HAP, the NAAQS value (which was used for the chronic noncancer 
risk assessment) takes into account multipathway exposures, so a 
separate multipathway screening value was not developed. Since we did 
not estimate any exceedances of the NAAQS in our chronic noncancer risk 
assessment, we do not expect any significant multipathway exposure and 
risk due to lead emissions from these facilities. For fluoranthene 
emissions, one facility emits this PB-HAP and the emissions exceed the 
screening-level threshold level for POM by a factor of four. Based on 
this screening analysis, we cannot rule out the potential for 
multipathway impacts of concern due to emissions of fluoranthene from 
the one facility. However, we do not expect fluoranthene emissions from 
PEPO processes, and we specifically request data regarding these 
emissions.
2. Facility-Wide Risk Assessment Results
    Table 20 displays the results of the facility-wide risk assessment. 
This assessment was conducted based on actual emission levels. For 
detailed facility-specific results, see Appendix 4 of the Draft 
Residual Risk Assessment for 7 Source Categories in the docket for this 
rulemaking.

          Table 20--PEPO Facility-Wide Risk Assessment Results
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Number of facilities analyzed................................         23
Cancer Risk:
    Estimated maximum facility-wide individual cancer risk            30
     (in 1 million)..........................................
    1Number of facilities with estimated facility-wide                 0
     individual cancer risk of 100-in-1 million or more......
    Number of facilities at which the PEPO source category             0
     contributes 50 percent or more to the facility-wide
     individual cancer risks of 100-in-1 million or more.....
    Number of facilities at which the PEPO source category            14
     contributes 50 percent or more to the facility-wide
     individual cancer risk of 1-in-1 million or more........
Chronic Noncancer Risk:
    Maximum facility-wide chronic noncancer TOSHI............          2
    Number of facilities with facility-wide maximum noncancer          1
     TOSHI greater than 1....................................
    Number of facilities at which the PEPO source category             0
     contributes 50 percent or more to the facility-wide
     maximum noncancer TOSHI of 1 or more....................
------------------------------------------------------------------------

    The facility-wide MIR from all HAP emissions at a facility that 
contains sources subject to the PEPO MACT standards is estimated to be 
30-in-1 million, based on actual emissions. Of the 23 facilities 
included in this

[[Page 1301]]

analysis, none have a facility-wide MIR of 100-in-1 million. There are 
20 facilities with a facility-wide MIR of 1-in-1 million or greater (10 
of these facilities have a facility-wide MIR equal to or greater than 
10 in a million). Fourteen of these facilities have PEPO production 
operations that contribute greater than 50 percent to the facility-wide 
risks.
    The facility-wide maximum individual chronic noncancer TOSHI is 
estimated to be 2 based on actual emissions. Of the 23 facilities 
included in this analysis, one has facility-wide maximum chronic 
noncancer TOSHI values greater than 1 (TOSHI of 2).
3. What is our proposed decision regarding risk acceptability?
    As noted in section III.C of this preamble, we weigh all health 
risk factors in our risk acceptability determination, including the 
MIR; the number of persons in various cancer and noncancer risk ranges; 
cancer incidence; the maximum noncancer HI; the maximum acute noncancer 
HQ; the extent of noncancer risks; the potential for adverse 
environmental effects; distribution of cancer and noncancer risks in 
the exposed population; and risk estimation uncertainty (54 FR 38044, 
September 14, 1989).
    For the PEPO source category, the risk analysis we performed 
indicates that the cancer risks to the individual most exposed could be 
up to 30-in-1 million due to both actual and allowable emissions. This 
value is considerably less than 100-in-1 million, which is the 
presumptive level of acceptability. The risk analysis also shows low 
cancer incidence (1 in every 50 years). The chronic noncancer TOSHI is 
estimated to be 1 due to emissions of chlorine.
    We estimate that the worst-case acute HQ value could exceed a value 
of 1 for two HAP, glycol ethers and acrolein, with a potential maximum 
acute HQ up to 6, based on the acute REL dose-response value for glycol 
ethers. For glycol ethers, we used the lowest acute REL of any of the 
glycol ethers with such health values (i.e., ethylene glycol monomethyl 
ether) to assess the other glycol ethers without such values. Two of 
the 23 facilities in this source category had an estimated acute HQ 
greater than 1. All other facilities modeled had an acute HQ less than 
1. The maximum acute HQ (based on the AEGL-1 dose-response value for 
acrolein) is 0.1. As described earlier in this preamble, the acute 
assessment includes some conservative assumptions and some 
uncertainties. Considering the improbable assumption that worst-case 
meteorological conditions are present at the same time that maximum 
hourly emissions of glycol ethers exceed the average hourly emission 
rate by a factor of 2 at all emission points simultaneously for both of 
these facilities and coincident with individuals being in the location 
of maximum impact, and considering the low acute HQ values, based on 
the AEGL-1 and ERPG-1 dose-response values collectively with the REL 
values, we believe it is unlikely that HAP emissions from this source 
category would result in acute health effects.
    Our screening level evaluation of the potential health risks 
associated with emissions of PB-HAP did not indicate potential for 
adverse multipathway impacts due to emissions of lead. The screening 
level evaluation indicated that the one facility that reported 
fluoranthene emissions exceeded the screening-level threshold for POM 
by a factor of 4; however, as explained in section III.B.7.e, our 
screening methods use worst-case scenarios and the results are biased 
high.
    Our additional analysis of facility-wide risks showed that the 
maximum facility-wide cancer risk is 30-in-1 million. The maximum 
chronic noncancer TOSHI is estimated to be 3, but the source category 
contributes less than one-third to the maximum facility-wide TOSHI.
    The EPA has weighed the various health risk measures and health 
factors, including risk estimation uncertainty, discussed above and in 
section III.B.7 of this preamble, and we are proposing that the risks 
from the PEPO source category are acceptable.
4. What is our proposed decision regarding ample margin of safety?
    We considered whether the MACT standards provide an ample margin of 
safety to protect public health. In this analysis, we investigated 
available emissions control options that might reduce the risk 
associated with emissions from the source category and considered this 
information along with all of the health risks and other health 
information considered in the risk acceptability determination.
    For the PEPO source category, we identified only one control option 
to further address risks from equipment leaks, which were shown to 
contribute approximately 47 percent to 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 
approximately 59 tpy from the baseline actual emissions level. We 
estimated that achieving these reductions would involve a capital cost 
of about $104,000,000, a total annualized cost of about $14,000,000 and 
a cost effectiveness of $244,000 per ton of HAP emissions reduced. The 
additional control requirement would achieve approximately 30-percent 
reduction in baseline risks at a very high cost. We estimate that the 
MACT allowable emissions from equipment leaks at this source category 
are approximately equal to the reported, actual emissions. Therefore, 
the estimated emission reduction, risk reduction and costs discussed 
above would also be applicable to the MACT allowable emissions level. 
We believe that the costs of this option are not reasonable, given the 
level of emission and risk reduction.
    In accordance with the approach established in the Benzene NESHAP, 
the EPA weighed all health risk measures and information considered in 
the risk acceptability determination, along with the costs and economic 
impacts of emissions controls, technological feasibility, uncertainties 
and other relevant factors in making our ample margin of safety 
determination. Considering the health risk information and the 
unreasonable cost effectiveness of the option identified, we propose 
that the existing MACT standards provide an ample margin of safety to 
protect public health and prevent an adverse environmental effect.

B. What are the results of the technology review?

    In the decade since the PEPO NESHAP was promulgated, EPA has 
developed 19 air toxics regulations for source categories that emit 
organic HAP from the same type of emissions sources that are present in 
the PEPO source category. We reviewed the regulatory requirements and/
or technical analyses for these 19 regulations for new practices, 
processes and control technologies. We also conducted a search of the 
RBLC for controls for VOC- and HAP-emitting processes in the SOCMI 
categories with permits dating back to 1997.
    We identified no advancements in practices, processes and control 
technologies applicable to the emission sources in the PEPO source 
category in our technology review.

C. What other actions are we proposing?

1. SSM Provisions
    As we have done in other recent risk and technology review 
rulemakings, we are proposing to eliminate the SSM

[[Page 1302]]

exemption in the PEPO MACT standards. Consistent with Sierra Club v. 
EPA, the EPA is proposing that standards in this rule would apply at 
all times. We are proposing several revisions to 40 CFR part 63, 
subpart PPP. Specifically, we are proposing to revise Table 1 to 
indicate that the requirements of 40 CFR 63.6(e) of the General 
Provisions do not apply. The 40 CFR 63.6(e) requires owners or 
operators to act according to the general duty to ``operate and 
maintain any affected source, including associated air pollution 
control equipment and monitoring equipment, in a manner consistent with 
safety and good air pollution control practices for minimizing 
emissions.'' We are separately proposing to incorporate this general 
duty to minimize into 40 CFR 63.1420(h). The 40 CFR 63.6(e) also 
requires the owner or operator of an affected source to develop a 
written SSM plan. We are proposing to remove the SSM plan requirement. 
We are proposing to remove the explanation of applicability of 
emissions standards during periods SSM in 40 CFR 63.1420(h); remove the 
malfunction plan from 40 CFR 63.1439(b); clarify that representative 
conditions do not include periods of SSM throughout the rule; remove 
references to periods of SSM in monitoring; remove the provisions for 
excused excursions in 40 CFR 63.1438(g) and revise the SSM-associated 
recordkeeping and reporting requirements in 40 CFR 63.1439(b) to 
require reporting and recordkeeping for periods of malfunction. We are 
also proposing to revise Table 1 to indicate that SSM-related 
provisions in 40 CFR 63.6(e)(1), 63.6(e)(3), 63.6(f)(1); 40 CFR 
63.7(e)(1); 40 CFR 63.8(c)(1); 40 CFR 63.10(c)(10), (11) and (15); and 
40 CFR 63.10(d)(5) of the General Provisions do not apply. We are also 
proposing to add requirements in 40 CFR 63.1434(c) to clarify that PRD 
releases to the atmosphere are violations of the emissions standards 
and to require pressure release alarms and to add requirements in 40 
CFR 63.1439(e)(9) to require reporting of any pressure device releases 
to the atmosphere with the periodic report. In addition, following our 
practice established in other risk and technology review rulemakings, 
we are proposing to promulgate an affirmative defense against civil 
penalties for exceedances of emission standards caused by malfunctions, 
as well as criteria for establishing the affirmative defense.
2. Electronic Reporting
    To increase the ease and efficiency of data submittal and improve 
data accessibility, we are proposing to require the submission of 
electronic copies of required performance tests for test methods that 
are supported by the ERT to EPA's WebFIRE database. These provisions 
are added in 40 CFR 63.1439(e)(10).

VII. Compliance Dates

    For the three MACT standards being addressed in this action, the 
proposed compliance date for the revised SSM requirements and 
electronic reporting requirements is the effective date of the 
promulgated revised standards. We are proposing these compliance dates 
because these requirements should be immediately implementable by the 
facilities upon the next occurrence of a malfunction or the performance 
of a performance test that is required to be submitted to the ERT. We 
also believe that the facilities should already be able to comply with 
the existing standards during periods of startup and shutdown.
    In accordance with CAA section 112(i)(3), the compliance date for 
PRD monitoring is 3 years from the effective date of the promulgated 
standards. This time period will allow facilities to purchase, install 
and test the equipment.
    For the facility in the PET continuous TPA high viscosity multiple 
end finisher subcategory subject to the Group IV Polymers and Resins 
MACT standards, the proposed compliance date for the new MACT standards 
applicable to equipment leaks and PCCT is the effective date of the 
promulgated standards. Since this facility is already performing the 
proposed equipment leak requirements and meeting the proposed PCCT 
standards, the facility should be able to comply immediately with the 
promulgated rule provisions. It should be feasible for the facility to 
conduct any additional recordkeeping required upon the promulgation 
date and information required in the next periodic report for these 
requirements would only reflect the period of time between the 
promulgation date and the periodic report due date.
    Beyond the revised SSM and electronic reporting requirements, there 
are no changes to the PAI and PEPO MACT standards.

VIII. Summary of Cost, Environmental and Economic Impacts

A. What are the affected sources?

    We anticipate that each facility in these seven source categories 
will be affected by these proposed amendments. We estimate there are 17 
existing facilities subject to the PAI MACT standards, 23 existing 
facilities subject to the PEPO MACT standards and 30 existing 
facilities subject to the Group IV Polymers and Resins MACT standards. 
We do not know of any new facilities that are expected to be 
constructed in the foreseeable future. Therefore, our impact analysis 
is focused on the existing sources affected by the MACT standards for 
these source categories.

B. What are the air quality impacts?

    No quantifiable air quality impacts are expected to result from the 
proposed amendments to these three MACT standards for seven source 
categories. For the two emissions sources, we are proposing new 
emissions standards for equipment leaks and PCCT in the PET continuous 
TPA high viscosity multiple end finisher subcategory regulated by the 
Group IV Polymers and Resins MACT standards, we are proposing to 
establish the MACT floor at the current emissions levels for the one 
facility in this subcategory. As a result, no additional emission 
reduction will be realized, although increases in emissions in the 
future will be prevented. For the proposed revisions to the MACT 
standards regarding SSM, while these changes may result in fewer 
emissions during these periods or less frequent periods of startup, 
shutdown or malfunction, these possible emission reductions are 
difficult to quantify and are not included in our assessment of air 
quality impacts.

C. What are the cost impacts?

    Under the proposed amendments, facilities in all seven source 
categories are expected to incur initial capital and annual operation 
and maintenance costs for the installation of PRD monitoring systems. 
The capital costs for each facility were estimated, based on data 
collected for other EPA projects. The memorandum, Draft Cost Impacts of 
the Revised NESHAP for 7 Source Categories, includes a complete 
description of the cost estimate methods used for this analysis and is 
available in the docket.

[[Page 1303]]

   Table 21--Cost Impacts of the Proposed PRD Monitoring Requirements
------------------------------------------------------------------------
                                       Total capital      Total annual
          Source category             costs  (million   costs  (million
                                          2010 $)        2010  $/year)
------------------------------------------------------------------------
PAI................................               3.2               0.5
PEPO...............................               4.7               0.7
P&R IV:
    ABS............................               0.9               0.1
    MBS............................               0.4               0.05
    Polystyrene Resins.............               2.0               0.3
    PET............................               2.8               0.4
    SAN............................               0.4               0.05
------------------------------------------------------------------------

D. What are the economic impacts?

    We estimate that there will be no more than a 0.5-percent price 
change and a similar reduction in output associated with the proposal. 
This is based on the costs of the rule and responsiveness of producers 
and consumers based on supply and demand elasticities for the 
industries affected by this proposal. The impacts to affected firms 
will be low because the annual compliance costs are quite small when 
compared to the annual revenues for the affected parent firms (much 
less than 1 percent for each). The impacts to affected consumers should 
also be quite small. Thus, there will not be any significant impacts on 
affected firms and their consumers as a result of this proposal.

E. What are the benefits?

    No quantifiable monetized benefits are expected to result from the 
proposed amendments to these three MACT standards for seven source 
categories. As explained in the air quality impacts section, there are 
no quantifiable emission reductions associated with the proposed 
amendments for these MACT standards and, therefore, there are no 
quantifiable health benefits to associate with reduced emissions.

IX. Request for Comments

    We are soliciting comments on this proposed action. All comments 
received during the comment period will be considered. In addition to 
general comments on the proposed actions, we are also interested in any 
additional data that may help to reduce the uncertainties inherent in 
the risk assessments. Such data should include supporting documentation 
in sufficient detail to allow characterization of the quality and 
representativeness of the data or information. Please see the following 
section for more information on submitting data.

X. Submitting Data Corrections

    The facility-specific data used in the source category risk 
analyses and facility-wide analyses for each source category subject to 
this action are available for download on the RTR Web page at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. These data files include detailed 
information for each HAP emissions release point at each facility 
included in the source category and all other HAP emissions sources at 
these facilities (facility-wide emissions sources). However, it is 
important to note that the source category risk analysis included only 
those emissions tagged with the MACT code associated with the source 
category subject to the risk analysis.
    If you believe the data are not representative or are inaccurate, 
please identify the data in question, provide your reason for concern, 
and provide the data that you believe are more accurate, if available. 
When you submit data, we request that you provide documentation of the 
basis for the revised values to support your 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 to the 
data fields appropriate for that information. The data fields that may 
be revised include the following:

------------------------------------------------------------------------
              Data element                          Definition
------------------------------------------------------------------------
Control Measure........................  Are control measures in place?
                                          (yes or no).
Control Measure Comment................  Select control measure from
                                          list provided, and briefly
                                          describe the control measure.
Delete.................................  Indicate here if the facility
                                          or record should be deleted.
Delete Comment.........................  Describes the reason for
                                          deletion.
Emission Calculation Method Code For     Code description of the method
 Revised Emissions.                       used to derive emissions. For
                                          example, continuous emission
                                          monitoring, material balance,
                                          stack test, etc.
Emission Process Group.................  Enter the general type of
                                          emission process associated
                                          with the specified emission
                                          point.
Fugitive Angle.........................  Enter release angle (clockwise
                                          from true North); orientation
                                          of the y-dimension relative to
                                          true North, measured positive
                                          for clockwise starting at 0
                                          degrees (maximum 89 degrees).
Fugitive Length........................  Enter dimension of the source
                                          in the east-west (x-)
                                          direction, commonly referred
                                          to as length (ft).
Fugitive Width.........................  Enter dimension of the source
                                          in the north-south (y-)
                                          direction, commonly referred
                                          to as width (ft).
Malfunction Emissions..................  Enter total annual emissions
                                          due to malfunctions (tpy).
Malfunction Emissions Max Hourly.......  Enter maximum hourly
                                          malfunction emissions here (lb/
                                          hr).
North American Datum...................  Enter datum for latitude/
                                          longitude coordinates (NAD27
                                          or NAD83); if left blank,
                                          NAD83 is assumed.
Process Comment........................  Enter general comments about
                                          process sources of emissions.
REVISED Address........................  Enter revised physical street
                                          address for MACT facility
                                          here.
REVISED City...........................  Enter revised city name here.

[[Page 1304]]

 
REVISED County Name....................  Enter revised county name here.
REVISED Emission Release Point Type....  Enter revised Emission Release
                                          Point Type here.
REVISED End Date.......................  Enter revised End Date here.
REVISED Exit Gas Flow Rate.............  Enter revised Exit Gas Flowrate
                                          here (ft\3\/sec).
REVISED Exit Gas Temperature...........  Enter revised Exit Gas
                                          Temperature here (F).
REVISED Exit Gas Velocity..............  Enter revised Exit Gas Velocity
                                          here (ft/sec).
REVISED Facility Category Code.........  Enter revised Facility Category
                                          Code here, which indicates
                                          whether facility is a major or
                                          area source.
REVISED Facility Name..................  Enter revised Facility Name
                                          here.
REVISED Facility Registry Identifier...  Enter revised Facility Registry
                                          Identifier here, which is an
                                          ID assigned by the EPA
                                          Facility Registry System.
REVISED HAP Emissions Performance Level  Enter revised HAP Emissions
 Code.                                    Performance Level here.
REVISED Latitude.......................  Enter revised Latitude here
                                          (decimal degrees).
REVISED Longitude......................  Enter revised Longitude here
                                          (decimal degrees).
REVISED MACT Code......................  Enter revised MACT Code here.
REVISED Pollutant Code.................  Enter revised Pollutant Code
                                          here.
REVISED Routine Emissions..............  Enter revised routine emissions
                                          value here (tpy).
REVISED SCC Code.......................  Enter revised SCC Code here.
REVISED Stack Diameter.................  Enter revised Stack Diameter
                                          here (ft).
REVISED Stack Height...................  Enter revised Stack Height here
                                          (Ft).
REVISED Start Date.....................  Enter revised Start Date here.
REVISED State..........................  Enter revised State here.
REVISED Tribal Code....................  Enter revised Tribal Code here.
REVISED Zip Code.......................  Enter revised Zip Code here.
Shutdown Emissions.....................  Enter total annual emissions
                                          due to shutdown events (tpy).
Shutdown Emissions Max Hourly..........  Enter maximum hourly shutdown
                                          emissions here (lb/hr).
Stack Comment..........................  Enter general comments about
                                          emission release points.
Startup Emissions......................  Enter total annual emissions
                                          due to startup events (tpy).
Startup Emissions Max Hourly...........  Enter maximum hourly startup
                                          emissions here (lb/hr).
Year Closed............................  Enter date facility stopped
                                          operations.
------------------------------------------------------------------------

    2. Fill in the commenter information fields for each suggested 
revision (i.e., commenter name, commenter organization, commenter email 
address, commenter phone number and 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[supreg] Access format and all accompanying documentation to 
Docket ID No. EPA-HQ-OAR-2011-0435 (through one of the methods 
described in the ADDRESSES section of this preamble). To expedite 
review of the revisions, it would also be helpful if you submitted a 
copy of your revisions to the EPA directly at RTR@epa.gov 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 request that all data revision comments be submitted in 
the form of updated Microsoft[supreg] Access files, which are provided 
on the http://www.epa.gov/ttn/atw/rrisk/rtrpg.html Web page.

XI. Statutory and Executive Order Reviews

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

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is a significant regulatory action because it raises novel legal 
and policy issues. Accordingly, the EPA submitted this action to OMB 
for review under Executive Order 12866 and Executive Order 13563 (76 FR 
3821, January 21, 2011) and any changes made in response to OMB 
recommendations have been documented in the docket for this action.

B. Paperwork Reduction Act

    The information collection requirements in this proposed rule have 
been submitted for approval to OMB under the Paperwork Reduction Act, 
44 U.S.C. 3501, et seq. The information collection requirements are not 
enforceable until OMB approves them. The information requirements are 
based on notification, recordkeeping and reporting requirements in the 
NESHAP General Provisions (40 CFR part 63, subpart A), which are 
mandatory for all operators subject to national emissions standards. 
These recordkeeping and reporting requirements are specifically 
authorized by CAA section 114 (42 U.S.C. 7414). All information 
submitted to the EPA pursuant to the recordkeeping and reporting 
requirements for which a claim of confidentiality is made is 
safeguarded according to agency policies set forth in 40 CFR part 2, 
subpart B.
    The OMB has previously approved the information collection 
requirements contained in the existing regulations being amended with 
this proposed rule (i.e., 40 CFR part 63, subparts JJJ, MMM, and PPP) 
under the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501, et 
seq. The OMB control numbers for the EPA's regulations in 40 CFR are 
listed in 40 CFR part 9. Burden is defined at 5 CFR 1320.3(b).
    For these proposed rules, the EPA is adding affirmative defense to 
the estimates of burden in the ICR for these rules. To provide the 
public with an estimate of the relative magnitude of the burden 
associated with an assertion of the affirmative defense position 
adopted by a source, the EPA has provided administrative adjustments to 
this ICR to show what the notification, recordkeeping and reporting 
requirements associated with the assertion of the affirmative defense 
might entail. The EPA's estimate for the required notification, reports 
and records for any individual incident, including the root cause 
analysis, totals $1,459 annually per MACT standard and is based on the 
time and effort

[[Page 1305]]

required of a source to review relevant data, interview plant employees 
and document the events surrounding a malfunction that has caused an 
exceedance of an emissions limit. The estimate also includes time to 
produce and retain the record and reports for submission to the EPA. 
The EPA provides this illustrative estimate of this burden because 
these costs are only incurred if there has been a violation and a 
source chooses to take advantage of the affirmative defense.
    Given the variety of circumstances under which malfunctions could 
occur, as well as differences among sources' operation and maintenance 
practices, we cannot reliably predict the severity and frequency of 
malfunction-related excess emissions events for a particular source. It 
is important to note that the EPA has no basis currently for estimating 
the number of malfunctions that would qualify for an affirmative 
defense. Current historical records would be an inappropriate basis, as 
source owners or operators previously operated their facilities in 
recognition that they were exempt from the requirement to comply with 
emissions standards during malfunctions. Of the number of excess 
emissions events reported by source operators, only a small number 
would be expected to result from a malfunction (based on the definition 
above) and only a subset of excess emissions caused by malfunctions 
would result in the source choosing to assert the affirmative defense. 
Thus, we believe the number of instances in which source operators 
might be expected to avail themselves of the affirmative defense will 
be extremely small. For this reason, we estimate no more than 1 or 2 
such occurrences for all sources subject to subparts JJJ, MMM and PPP 
over the 3-year period covered by this ICR. We expect to gather 
information on such events in the future and will revise this estimate 
as better information becomes available.
1. Group IV Polymers and Resins MACT Standards
    The ICR document prepared by the EPA for the amendments to the 
Group IV Polymers and Resins MACT standards has been assigned EPA ICR 
number 1737.01. Burden changes associated with these amendments would 
result from new recordkeeping and reporting requirements associated 
with the cooling towers and equipment leak provisions for one facility 
and PRD monitoring systems and affirmative defense provisions for all 
facilities subject to the MACT standards.
    We estimate 30 regulated facilities are currently subject to 40 CFR 
part 63, subpart JJJ. The annual monitoring, reporting and 
recordkeeping burden for this collection (averaged over the first 3 
years after the effective date of the standards) for these amendments 
to subpart JJJ is estimated to be 327 labor hours at a cost of $19,947 
per year. There is no estimated change in annual burden to the Federal 
government for these amendments.
2. Pesticide Active Ingredient Production MACT Standards
    The ICR document prepared by the EPA for the amendments to the PAI 
MACT standards has been assigned EPA ICR number 1807.05. Burden changes 
associated with these amendments would result from new recordkeeping 
and reporting requirements associated with PRD monitoring systems and 
affirmative defense provisions for all facilities subject to the MACT 
standards.
    We estimate 17 regulated facilities are currently subject to 40 CFR 
part 63, subpart MMM. The annual monitoring, reporting and 
recordkeeping burden for this collection (averaged over the first 3 
years after the effective date of the standards) for these amendments 
to subpart MMM is estimated to be 187 labor hours at a cost of $11,433 
per year. There is no estimated change in annual burden to the Federal 
government for these amendments.
3. Polyether Polyols Production MACT Standards
    The ICR document prepared by the EPA for the amendments to the PEPO 
MACT standards has been assigned EPA ICR number 1811.06. Burden changes 
associated with these amendments would result from new recordkeeping 
and reporting requirements associated with PRD monitoring systems and 
affirmative defense provisions for all facilities subject to the MACT 
standards.
    We estimate 23 regulated facilities are currently subject to 40 CFR 
part 63, subpart PPP. The annual monitoring, reporting and 
recordkeeping burden for this collection (averaged over the first 3 
years after the effective date of the standards) for these amendments 
to subpart PPP is estimated to be 253 labor hours at a cost of $15,433 
per year. There is no estimated change in annual burden to the Federal 
government for these amendments.
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for the 
EPA's regulations in 40 CFR are listed in 40 CFR part 9. When these ICR 
are approved by OMB, the agency will publish a technical amendment to 
40 CFR part 9 in the Federal Register to display the OMB control 
numbers for the approved information collection requirements contained 
in the final rules.
    To comment on the agency's need for this information, the accuracy 
of the provided burden estimates and any suggested methods for 
minimizing respondent burden, the EPA has established a public docket 
for this rule, which includes this ICR, under Docket ID number EPA-HQ-
OAR-2011-0435. Submit any comments related to the ICR to the EPA and 
OMB. See the ADDRESSES section at the beginning of this notice for 
where to submit comments to the EPA. Send comments to OMB at the Office 
of Information and Regulatory Affairs, Office of Management and Budget, 
725 17th Street NW., Washington, DC 20503, Attention: Desk Office for 
EPA. Because OMB is required to make a decision concerning the ICR 
between 30 and 60 days after January 9, 2012, a comment to OMB is best 
assured of having its full effect if OMB receives it by February 8, 
2012. The final rule will respond to any OMB or public comments on the 
information collection requirements contained in this proposal.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act 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 impacts of this proposed rule on 
small entities, small entity is defined as: (1) A small business as 
defined by the Small Business Administration's (SBA) 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 that is independently owned and operated 
and is not dominant in its field. According to the SBA small business 
standards definitions, for the Group IV Polymers and Resins source 
categories, which have the NAICS code of 325211 (i.e., Plastics 
Material and Resin Manufacturing), the SBA small business

[[Page 1306]]

size standard is 750 employees. For the PEPO source category, which has 
the NAICS code of 325199 (i.e., All Other Basic Organic Chemical 
Manufacturing), the SBA small business size standard is 1,000 
employees. For the PAI source category, which has the NAICS codes of 
325199 (i.e., All Other Basic Organic Chemical Manufacturing) and 
325320 (i.e., Pesticide and Other Agricultural Chemical Manufacturing), 
the SBA small business size standards are 1,000 employees and 500 
employees, respectively.
    After considering the economic impacts of this proposed rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. Only one 
small business in the PAI source category is impacted and only one 
small business in the Group IV Polymers and Resins source categories is 
impacted. For each affected small business, the impact of this proposal 
is an annual compliance cost of less than 1 percent of the parent 
firm's revenues. There are no affected small businesses in the PEPO 
source category. All of the other companies affected by this rule are 
generally large integrated corporations that are not considered to be 
small entities per the definitions provided in this section.
    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 does not contain a Federal mandate under the 
provisions of Title II of the Unfunded Mandates Reform Act of 1995 
(UMRA), 2 U.S.C. 1531-1538 for state, local or tribal governments or 
the private sector. The proposed rule would not result in expenditures 
of $100 million or more for state, local and tribal governments, in 
aggregate, or the private sector in any 1 year. This proposed rule 
would require the use of PRD monitoring systems, but the nationwide 
annualized costs of this proposed requirement are estimated to be 
approximately $2 million for affected sources. Thus, 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 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

    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. The burden to the respondents 
and the states is approximately $2,000,000 for the three MACT standards 
addresses in this proposed rule. 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 the EPA and state and local 
governments, the 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). Thus, 
Executive Order 13175 does not apply to this action.
    The EPA specifically solicits additional comment on this proposed 
action from tribal officials.

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

    This 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 EPA does not believe 
the environmental health or safety risks addressed by this action 
present a disproportionate risk to children. This action would not 
cause appreciable increases in emissions or emissions-related health 
risks. The EPA's risk assessments (included in the docket for this 
proposed rule) demonstrate that the existing regulations are associated 
with an acceptable level of risk and provide an ample margin of safety 
to protect public health and prevent adverse environmental effects.

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

    This action is not a ``significant energy action,'' as defined 
under Executive Order 13211, (66 FR 28355, May 22, 2001), because it is 
not likely to have significant adverse effect on the supply, 
distribution or use of energy. This action will not create any new 
requirements and, therefore, no additional costs for sources in the 
energy supply, distribution or use sectors.

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 (15 U.S.C. 272 note) directs 
the 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 
the EPA to provide Congress, through OMB, explanations when the agency 
decides not to use available and applicable VCS.
    This proposed rulemaking involves technical standards. The EPA 
proposes to use ASTM D2908-74 or 91 and ASTM D3370-76 or 96a for the 
PCCT at the one Group IV Polymers and Resins facility in the PET 
continuous TPA high viscosity multiple end finisher subcategory. No 
applicable VCS were identified for these methods.
    The EPA welcomes comments on this aspect of this proposed 
rulemaking and, specifically, invites the public to identify 
potentially-applicable VCS and to explain why such standards should be 
used in this regulation.
    Under section 63.7(f) and section 63.8(f) of Subpart A of the 
General Provisions, a source may apply to the EPA for permission to use 
alternative test methods or alternative monitoring requirements in 
place of any required testing methods, performance specifications or 
procedures in the proposed rule.

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.

[[Page 1307]]

    To examine the potential for any environmental justice issues that 
might be associated with the level of the standards for each source 
category, we performed a comparative analysis of the demographics of 
the population within the vicinity of the facilities in these source 
categories (i.e., within a 3-mile radius) and the national average 
demographic distributions. The results of this analysis show that most 
demographic categories are within 2 percentage points of national 
averages, except for the African American population, which exceeds the 
national average by 6 percentage points (18 percent versus 12 percent). 
The EPA has determined that the current health risks posed by emissions 
from these source categories are acceptable and provide an ample margin 
of safety to protect public health and prevent adverse environmental 
effects. The proposed rule will not have disproportionately high and 
adverse human health or environmental effects on minority or low-income 
populations because it maintains the level of environmental protection 
for all affected populations.

List of Subjects for 40 CFR Part 63

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

    Dated: November 30, 2011.
Lisa P. Jackson,
Administrator.

    For the reasons stated in the preamble, the Environmental 
Protection Agency (EPA) proposes to amend Title 40, chapter I, of the 
Code of Federal Regulations (CFR) as follows:

PART 63--[AMENDED]

    1. The authority citation for part 63 continues to read as follows:

    Authority:  42 U.S.C. 7401, et seq.

Subpart JJJ--[Amended]

    2. Section 63.1310 is amended by:
    a. Revising paragraphs (a)(4) introductory text, (a)(4)(iv) and 
(a)(4)(vi);
    b. Revising paragraphs (c)(1) and (d) introductory text;
    c. Revising paragraph (j); and
    d. Adding paragraph (k) to read as follows:

Sec.  63.1310  Applicability and designation of affected sources.

    (a) * * *
    (4) Emission points and equipment. The affected source also 
includes the emission points and components specified in paragraphs 
(a)(4)(i) through (vi) of this section that are associated with each 
applicable group of one or more TPPU constituting an affected source.
* * * * *
    (iv) Each process contact cooling tower used in the manufacture of 
poly (ethylene terephthalate) resin (PET) that is associated with a new 
affected source.
* * * * *
    (vi) Components required by or utilized as a method of compliance 
with this subpart, which may include control devices and recovery 
devices.
* * * * *
    (c) * * *
    (1) Components and equipment that do not contain organic HAP and is 
located within a TPPU that is part of an affected source;
* * * * *
    (d) Processes excluded from the affected source. The processes 
specified in paragraphs (d)(1) through (5) of this section are not part 
of the affected source and are not subject to the requirements of both 
this subpart and subpart A of this part:
* * * * *
    (j) Applicability of this subpart. (1) The emission limitations set 
forth in this subpart and the emission limitations referred to in this 
subpart shall apply at all times except during periods of non-operation 
of the affected source (or specific portion thereof) resulting in 
cessation of the emissions to which this subpart applies.
    (2) The emission limitations set forth in subpart H of this part, 
as referred to in Sec.  63.1331, shall apply at all times except during 
periods of non-operation of the affected source (or specific portion 
thereof) in which the lines are drained and depressurized, resulting in 
cessation of the emissions to which Sec.  63.1331 applies.
    (3) The owner or operator shall not shut down items of equipment 
that are required or utilized for compliance with this subpart during 
times when emissions (or, where applicable, wastewater streams or 
residuals) are being routed to such items of equipment, if the shutdown 
would contravene requirements of this subpart applicable to such items 
of equipment
    (4) General duty. At all times, the owner or operator must operate 
and maintain any affected source, including associated air pollution 
control equipment and monitoring equipment, in a manner consistent with 
safety and good air pollution control practices for minimizing 
emissions. Determination of whether such operation and maintenance 
procedures are being used will be based on information available to the 
Administrator, which may include, but is not limited to, monitoring 
results, review of operation and maintenance procedures, review of 
operation and maintenance records and inspection of the source.
    (k) Affirmative defense for exceedance of emission limit during 
malfunction. In response to an action to enforce the standards set 
forth in this subpart, the owner or operator may assert an affirmative 
defense to a claim for civil penalties for exceedances of such 
standards that are caused by malfunction, as defined at Sec.  63.2. 
Appropriate penalties may be assessed, however, if the owner or 
operator fails to meet their burden of proving all of the requirements 
in the affirmative defense. The affirmative defense shall not be 
available for claims for injunctive relief.
    (1) To establish the affirmative defense in any action to enforce 
such a limit, the owner or operator must timely meet the notification 
requirements in paragraph (k)(2) of this section, and must prove by a 
preponderance of evidence that:
    (i) The excess emissions:
    (A) Were caused by a sudden, infrequent and unavoidable failure of 
air pollution control and monitoring equipment, process equipment or a 
process to operate in a normal or usual manner; and
    (B) Could not have been prevented through careful planning, proper 
design or better operation and maintenance practices; and
    (C) Did not stem from any activity or event that could have been 
foreseen and avoided or planned for; and
    (D) Were not part of a recurring pattern indicative of inadequate 
design, operation or maintenance; and
    (ii) Repairs were made as expeditiously as possible when the 
applicable emission limitations were being exceeded. Off-shift and 
overtime labor were used to the extent practicable to make these 
repairs; and
    (iii) The frequency, amount and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (iv) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, personal injury or severe property damage; and
    (v) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment and human 
health; and

[[Page 1308]]

    (vi) All emissions monitoring and control systems were kept in 
operation if at all possible, consistent with safety and good air 
pollution control practices; and
    (vii) All of the actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (viii) At all times, the affected source was operated in a manner 
consistent with good practices for minimizing emissions; and
    (ix) A written root cause analysis has been prepared, the purpose 
of which is to determine, correct and eliminate the primary causes of 
the malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis shall also specify, using best monitoring 
methods and engineering judgment, the amount of excess emissions that 
were the result of the malfunction.
    (2) Notification. The owner or operator of the affected source 
experiencing an exceedance of its emission limit(s) during a 
malfunction shall notify the Administrator by telephone or facsimile 
(FAX) transmission as soon as possible, but no later than 2 business 
days after the initial occurrence of the malfunction, if it wishes to 
avail itself of an affirmative defense to civil penalties for that 
malfunction. The owner or operator seeking to assert an affirmative 
defense shall also submit a written report to the Administrator within 
45 days of the initial occurrence of the exceedance of the standard in 
this subpart to demonstrate, with all necessary supporting 
documentation, that it has met the requirements set forth in paragraph 
(k)(1) of this section. The owner or operator may seek an extension of 
this deadline for up to 30 additional days by submitting a written 
request to the Administrator before the expiration of the 45-day 
period. Until a request for an extension has been approved by the 
Administrator, the owner or operator is subject to the requirement to 
submit such report within 45 days of the initial occurrence of the 
exceedance.
    3. Section 63.1311 is amended by revising paragraph (d)(6) to read 
as follows:

Sec.  63.1311  Compliance dates and relationship of this subpart to 
existing applicable rules.

* * * * *
    (d) * * *
    (6) Notwithstanding paragraphs (d)(1) through (5) of this section, 
existing affected sources whose primary product, as determined using 
the procedures specified in Sec.  63.1310(f), is PET shall be in 
compliance with Sec.  63.1331 no later than August 6, 2002.
* * * * *
    4. Section 63.1312 is amended by:
    a. Removing the term ``Start-up, shutdown, and malfunction plan 
(Sec.  63.101)'' in paragraph (a); and
    b. Adding the definition for ``Affirmative defense'' in 
alphabetical order in paragraph (b) to read as follows:

Sec.  63.1312  Definitions.

* * * * *
    (b) * * *
    Affirmative defense means, in the context of an enforcement 
proceeding, a response or defense put forward by a defendant, regarding 
which the defendant has the burden of proof, and the merits of which 
are independently and objectively evaluated in a judicial or 
administrative proceeding.
* * * * *

Sec.  63.1319  [Amended]

    5. Section 63.1319 is amended by removing ``Lfimits'' and adding in 
its place ``limits'' in the heading for paragraph (c).
    6. Section 63.1324 is amended by revising the first two sentences 
of paragraph (c)(4)(ii)(C) to read as follows:

Sec.  63.1324  Batch process vents--monitoring equipment.

* * * * *
    (c) * * *
    (4) * * *
    (ii) * * *
    (C) The owner or operator may prepare and implement a gas stream 
flow determination plan that documents an appropriate method which will 
be used to determine the gas stream flow. The plan shall require 
determination of gas stream flow by a method which will at least 
provide a value for either a representative or the highest gas stream 
flow anticipated in the scrubber during representative operating 
conditions other than malfunctions. * * *
* * * * *
    7. Section 63.1329 is amended by:
    a. Revising the first sentence of paragraph (c) introductory text; 
and
    b. Adding paragraphs (c)(2)(i) and (ii) to read as follows:

Sec.  63.1329  Process contact cooling towers provisions.

* * * * *
    (c) Existing affected source requirements. The owner or operator of 
an existing affected source subject to this section who manufactures 
PET using a continuous terephthalic acid high viscosity multiple end 
finisher process and who is subject or becomes subject to 40 CFR part 
60, subpart DDD, shall maintain an ethylene glycol concentration in the 
process contact cooling tower at or below 6.0 percent by weight 
averaged on a daily basis over a rolling 14-day period of operating 
days. * * *
* * * * *
    (2) * * *
    (i) Where 40 CFR 60.564(j)(1) requires the use of ASTM D2908-74 or 
91, ``Standard Practice for Measuring Volatile Organic Matter in Water 
by Aqueous-Injection Gas Chromatography,'' ASTM D2908-91 (2011), D2908-
91 (2005), D2908-91 (2001), D2908-91 or D2908-74 may be used.
    (ii) Where 40 CFR 60.564(j)(1)(i) requires the use of ASTM D3370-76 
or 96a, ``Standard Practices for Sampling Water,'' ASTM D3370-10, 
D3370-08, D3370-07, D3370-96a or D3370-76 may be used.
    8. Section 63.1331 is amended by adding paragraphs (a)(9) and (c) 
to read as follows:

Sec.  63.1331  Equipment leak provisions.

    (a) * * *
    (9) Requirements for pressure relief devices. For pressure relief 
devices, the owner or operator must meet the requirements of this 
paragraph. Any release to the atmosphere from a pressure relief device 
in organic HAP service constitutes a violation of this rule. The owner 
or operator must install, maintain and operate release indicators as 
specified in paragraphs (a)(9)(i) and (ii) of this section unless the 
pressure relief routes to a closed vent system and control device 
designed and operated in accordance with the requirements of this 
subpart. For any pressure relief devices, the owner or operator must 
comply with the recordkeeping and reporting provisions in this 
paragraph (a) and Sec.  63.1335(e)(9). For any release, the owner or 
operator must submit the report specified in Sec.  63.1335(e)(9), as 
described in paragraph (a)(9)(iii) of this section.
    (i) A release indicator must be properly installed on each pressure 
relief device in such a way that it will indicate when an emission 
release has occurred.
    (ii) Each indicator must be equipped with an alert system that will 
notify an operator immediately and automatically when the pressure 
relief device is open. The alert must be located such that the signal 
is detected and recognized easily by an operator.
    (iii) For any instance that the release indicator indicates that a 
pressure relief device is open, the owner or operator must notify the 
Administrator that a pressure release has occurred and

[[Page 1309]]

submit to the Administrator the report specified in Sec.  
63.1335(e)(9). This report is required even if the owner or operator 
elects to follow the procedures specified in Sec.  63.1310(k) to 
establish an affirmative defense.
* * * * *
    (c)(1) Each affected source producing PET using a continuous TPA 
high viscosity multiple end finisher process shall monitor for leaks 
upon startup following an outage where changes have been made to 
equipment in gas/vapor or light liquid service. This leak check shall 
consist of the introduction of hot ethylene glycol vapors into the 
system for a period of no less than 2 hours during which time sensory 
monitoring of the equipment shall be conducted.
    (2) A leak is determined to be detected if there is evidence of a 
potential leak found by visual, audible or olfactory means.
    (3) When a leak is detected, it shall be repaired as soon as 
practical, but not later than 15 days after it is detected, except as 
provided in Sec.  63.171.
    (i) The first attempt at repair shall be made no later than 5 days 
after each leak is detected.
    (ii) Repaired shall mean that the visual, audible, olfactory or 
other indications of a leak have been eliminated; that no bubbles are 
observed at potential leak sites during a leak check using soap 
solution; or that the system will hold a test pressure.
    (4) When a leak is detected, the following information shall be 
recorded and kept for 2 years and reported in the next periodic report:
    (i) The instrument and the equipment identification number and the 
operator name, initials or identification number.
    (ii) The date the leak was detected and the date of first attempt 
to repair the leak.
    (iii) The date of successful repair of the leak.
    9. Section 63.1332 is amended by:
    a. Removing and reserving paragraph (f)(1); and
    b. Revising paragraph (f)(2) introductory text to read as follows:

Sec.  63.1332  Emissions averaging provisions.

* * * * *
    (f) * * *
    (2) Emissions during periods of monitoring excursions, as defined 
in Sec.  63.1334(f). For these periods, the calculation of monthly 
credits and debits shall be adjusted as specified in paragraphs 
(f)(2)(i) through (iii) of this section.
* * * * *
    10. Section 63.1333 is amended by revising paragraph (a) 
introductory text to read as follows:

Sec.  63.1333  Emissions averaging provisions.

    (a) Performance testing shall be conducted under such conditions as 
the Administrator specifies to the owner or operator based on 
representative performance of the affected source for the period being 
tested and in accordance with Sec.  63.7(a)(1), (a)(3), (d), (e)(2), 
(e)(4), (g) and (h), with the exceptions specified in paragraphs (a)(1) 
through (5) of this section and the additions specified in paragraphs 
(b) through (d) of this section. Upon request, the owner or operator 
shall make available to the Administrator such records as may be 
necessary to determine the conditions of performance tests. Sections 
63.1314 through 63.1330 also contain specific testing requirements.
* * * * *

Sec.  63.1334  [Amended]

    11. Section 63.1334 is amended by:
    a. Removing and reserving paragraphs (f)(1)(v)(B) through (D);
    b. Removing and reserving paragraphs (f)(2)(ii)(B)(2) through (4);
    c. Removing and reserving paragraphs (f)(5)(ii) through (iv);
    d. Removing and reserving paragraphs (f)(6)(ii) through (iv); and
    e. Removing and reserving paragraph (g).
    12. Section 63.1335 is amended by:
    a. Revising paragraphs (b)(1) introductory text, (b)(1)(i) 
introductory text, and (b)(1)(i)(A) and (B);
    b. Removing and reserving paragraph ((b)(1)(i)(C));
    c. Revising paragraph (b)(1)(ii);
    d. Revising paragraph (d)(7)(i);
    e. Removing and reserving paragraphs (d)(7)(ii) through (iv);
    f. Revising the first sentence of paragraph (e) introductory text, 
the first sentence of paragraph (e)(3) introductory text, and paragraph 
(e)(3)(v);
    g. Removing and reserving paragraph (e)(3)(viii);
    h. Revising paragraph (e)(3)(ix)(B)
    i. Revising the first two sentences of paragraph (e)(6) 
introductory text, (e)(6)(iii)(E), (e)(6)(xii)(A)(1), and 
(e)(6)(xii)(D);
    j. Adding paragraphs (e)(9) and (10);
    k. Revising paragraph (h)(1)(i);
    l. Removing and reserving paragraph (h)(1)(ii)(C);
    m. Revising the first sentence of paragraph (h)(1)(iii);
    n. Revising paragraphs (h)(2)(iii) through (iv).
    The revisions read as follows:

Sec.  63.1335  General recordkeeping and reporting provisions.

* * * * *
    (b) * * *
    (1) Malfunction recordkeeping and reporting. (i) Records of 
malfunctions. The owner or operator shall keep the records specified in 
paragraphs (b)(1)(i)(A) through (C) of this section.
    (A) Records of the occurrence and duration of each malfunction of 
operation of process equipment or control devices or recovery devices 
or continuous monitoring systems used to comply with this subpart, and 
an estimate of the excess emissions released.
    (B) Records of actions taken during periods of malfunction to 
minimize emissions in accordance with Sec.  63.1420(h)(4), including 
corrective actions to restore malfunctioning process and air pollution 
control and monitoring equipment to its normal or usual manner of 
operation.
* * * * *
    (ii) Reports of malfunctions. For the purposes of this subpart, 
reports of malfunctions shall be submitted on the same schedule as the 
Periodic Reports required under paragraph (e)(6) of this section. If a 
malfunction occurred during the reporting period, the report must 
include the number, duration, excess emissions estimate and a brief 
description for each type of malfunction which occurred during the 
reporting period and which caused or may have caused any applicable 
emission limitation to be exceeded. The report must also include a 
description of actions taken by an owner or operator during a 
malfunction of an affected source to minimize emissions in accordance 
with Sec.  63.1420(h)(4), including actions taken to correct a 
malfunction.
* * * * *
    (d) * * *
    (7) * * *
    (i) Monitoring system malfunctions, breakdowns, repairs, 
calibration checks and zero (low-level) and high-level adjustments;
* * * * *
    (e) * * * In addition to the reports and notifications required by 
subpart A of this part as specified in Table 1 of this subpart, the 
owner or operator of an affected source shall prepare and submit the 
reports listed in paragraphs (e)(3) through (10) of this section, as 
applicable. * * *
* * * * *
    (3) * * * Owners or operators of affected sources requesting an 
extension for compliance; requesting approval to use alternative 
monitoring parameters, alternative continuous monitoring and 
recordkeeping or alternative controls; requesting approval to use 
engineering

[[Page 1310]]

assessment to estimate emissions from a batch emissions episode, as 
described in Sec.  63.1323(b)(6)(i)(C); or wishing to establish 
parameter monitoring levels according to the procedures contained in 
Sec.  63.1334(c) or (d), shall submit a Precompliance Report according 
to the schedule described in paragraph (e)(3)(i) of this section. * * *
* * * * *
    (v) The owner or operator shall report the intent to use 
alternative emissions standards to comply with the provisions of this 
subpart in the Precompliance Report. The Administrator may deem 
alternative emissions standards to be equivalent to the standard 
required by the subpart, under the procedures outlined in Sec.  
63.6(g).
* * * * *
    (ix) * * *
    (B) Supplements to the Precompliance Report may be submitted to 
request approval to use alternative monitoring parameters, as specified 
in paragraph (e)(3)(iii) of this section; to use alternative continuous 
monitoring and recordkeeping, as specified in paragraph (e)(3)(iv) of 
this section; to use alternative controls, as specified in paragraph 
(e)(3)(v) of this section; to use engineering assessment to estimate 
emissions from a batch emissions episode, as specified in paragraph 
(e)(3)(vi) of this section; to establish parameter monitoring levels 
according to the procedures contained in Sec.  63.1334(c) or (d), as 
specified in paragraph (e)(3)(vii) of this section.
* * * * *
    (6) Periodic Reports. For existing and new affected sources, the 
owner or operator shall submit Periodic Reports as specified in 
paragraphs (e)(6)(i) through (xi) of this section. In addition, for 
equipment leaks subject to Sec.  63.1331, with the exception of Sec.  
63.1331(c), the owner or operator shall submit the information 
specified in Sec.  63.182(d) under the conditions listed in Sec.  
63.182(d), and for heat exchange systems subject to Sec.  63.1328, the 
owner or operator shall submit the information specified in Sec.  
63.104(f)(2) as part of the Periodic Report required by this paragraph 
(e)(6). * * *
* * * * *
    (iii) * * *
    (E) The information in paragraph (b)(1)(ii) of this section for 
reports of malfunctions.
* * * * *
    (xii) * * *
    (A) * * *
    (1) A control or recovery device for a particular emission point or 
process section has one or more excursions, as defined in Sec.  
63.1334(f), for a semiannual reporting period; or
* * * * *
    (D) After quarterly reports have been submitted for an emission 
point for 1 year without one or more excursions occurring (during that 
year), the owner or operator may return to semiannual reporting for the 
emission point or process section.
* * * * *
    (9) Pressure relief device deviation report. If any pressure relief 
device in organic HAP service or any piece of equipment or closed vent 
system has discharged to the atmosphere, as specified in Sec.  
63.1331(a)(9), the owner or operator must submit to the Administrator 
in the next Periodic Report:
    (i) The source, nature and cause of the discharge.
    (ii) The date, time and duration of the discharge.
    (iii) An estimate of the quantity of total organic HAP emitted 
during the discharge and the method used for determining this quantity.
    (iv) The actions taken to prevent this discharge.
    (v) The measures adopted to prevent future such discharges.
    (10) Electronic reporting. (i) Within 60 days after the date of 
completing each performance test (defined in Sec.  63.2), as required 
in this subpart, the owner or operator must transmit the results of the 
performance tests required by this subpart to EPA's WebFIRE database by 
using the Compliance and Emissions Data Reporting Interface (CEDRI) 
that is accessed through the EPA's Central Data Exchange (CDX) (see 
http://www.epa.gov/cdx). Performance test data must be submitted in the 
file format generated through use of EPA's Electronic Reporting Tool 
(ERT) (see http://www.epa.gov/ttn/chief/ert/index.html). Only data 
collected using test methods on the ERT Web site are subject to this 
requirement for submitting reports electronically to WebFIRE. Owners or 
operators who claim that some of the information being submitted for 
performance tests is confidential business information (CBI) must 
submit a complete ERT file including information claimed to be CBI on a 
compact disk or other commonly used electronic storage media 
(including, but not limited to, flash drives) to EPA. The electronic 
media must be clearly marked as CBI and mailed to U.S. EPA/OAPQS/CORE 
CBI Office, Attention: WebFIRE Administrator, MD C404-02, 4930 Old Page 
Rd., Durham, NC 27703. The same ERT file with the CBI omitted must be 
submitted to EPA via CDX as described earlier in this paragraph. At the 
discretion of the delegated authority, you must also submit these 
reports, including the confidential business information, to the 
delegated authority in the format specified by the delegated authority.
    (ii) All reports required by this subpart not subject to the 
requirements in paragraphs (e)(10)(i) and (ii) of this section must be 
sent to the Administrator at the appropriate address listed in Sec.  
63.13. The Administrator or the delegated authority may request a 
report in any form suitable for the specific case (e.g., by commonly 
used electronic media such as Excel spreadsheet, on CD or hard copy). 
The Administrator retains the right to require submittal of reports 
subject to paragraph (e)(10)(i) and (ii) of this section in paper 
format.
* * * * *
    (h) * * *
    (1) * * *
    (i) The monitoring system is capable of detecting unrealistic or 
impossible data during periods of operation (e.g., a temperature 
reading of -200 [deg]C on a boiler), and will alert the operator by 
alarm or other means. The owner or operator shall record the 
occurrence. All instances of the alarm or other alert in an operating 
day constitute a single occurrence.
* * * * *
    (iii) The monitoring system is capable of detecting unchanging data 
during periods of operation, except in circumstances where the presence 
of unchanging data is the expected operating condition based on past 
experience (e.g., pH in some scrubbers), and will alert the operator by 
alarm or other means. * * *
* * * * *
    (2) * * *
    (iii) The owner or operator shall retain the records specified in 
paragraphs (h)(1)(i) through (iii) of this section, for the duration 
specified in this (h). For any calendar week, if compliance with 
paragraphs (h)(1)(i) through (iv) of this section does not result in 
retention of a record of at least one occurrence or measured parameter 
value, the owner or operator shall record and retain at least one 
parameter value during a period of operation.
    (iv) For purposes of this paragraph (h), an excursion means that 
the daily average (or batch cycle daily average) value of monitoring 
data for a parameter is greater than the maximum, or less than the 
minimum established value.
    13. Table 1 to Part JJJ of Subpart 63 is amended by:

[[Page 1311]]

    a. Revising entries 63.6(e), 63.6(e)(1)(i), and 63.6(e)(1)(ii);
    b. Removing entries 63.6(e)(3)(i) through 63.6(e)(3)(ix);
    c. Adding entries 63.6(e)(3) and 63.6(f)(1);
    d. Revising entry 63.7(e)(1);
    e. Revising entries 63.8(c)(1)(i) and 63.8(c)(1)(iii);
    f. Removing entries 63.10(d)(5)(i) and 63.10(d)(5)(ii);
    g. Adding entry 63.10(d)(5);
    h. Removing footnote (a).
    The revisions and additions read as follows:

 Table 1 to Subpart JJJ of Part 63--Applicability of General Provisions
                     to Subpart JJJ Affected Sources
------------------------------------------------------------------------
                                    Applies to
           Reference               subpart JJJ          Explanation
------------------------------------------------------------------------
 
                              * * * * * * *
Sec.   63.6(e)................  Yes..............  Except as otherwise
                                                    specified for
                                                    individual
                                                    paragraphs.
Sec.   63.6(e)(1)(i)..........  No...............  See Sec.
                                                    63.1310(j)(4) for
                                                    general duty
                                                    requirement.
Sec.   63.6(e)(1)(ii).........  No...............
 
                              * * * * * * *
Sec.   63.6(e)(3).............  No...............
Sec.   63.6(f)(1).............  No...............
 
                              * * * * * * *
Sec.   63.7(e)(1).............  No...............  See Sec.
                                                    63.1333(a).
 
                              * * * * * * *
Sec.   63.8(c)(1)(i)..........  No...............
 
                              * * * * * * *
Sec.   63.8(c)(1)(iii)........  No...............
 
                              * * * * * * *
Sec.   63.10(d)(5)............  No...............  See Sec.
                                                    63.1335(b)(1)(ii)
                                                    for malfunction
                                                    reporting
                                                    requirements.
 
                              * * * * * * *
------------------------------------------------------------------------

* * * * *

Subpart MMM--[Amended]

    14. Section 63.1360 is amended by revising paragraphs (e)(1), (3), 
and (4) and adding paragraph (k) to read as follows:

Sec.  63.1360  Applicability.

* * * * *
    (e) Applicability of this subpart. (1) Each provision set forth in 
this subpart shall apply at all times.
* * * * *
    (3) The owner or operator shall not shut down items of equipment 
that are required or utilized for compliance with the emissions 
limitations of this subpart during times when emissions (or, where 
applicable, wastewater streams or residuals) are being routed to such 
items of equipment, if the shutdown would contravene emissions 
limitations of this subpart applicable to such items of equipment.
    (4) General duty. At all times, the owner or operator must operate 
and maintain any affected source, including associated air pollution 
control equipment and monitoring equipment, in a manner consistent with 
safety and good air pollution control practices for minimizing 
emissions. Determination of whether such operation and maintenance 
procedures are being used will be based on information available to the 
Administrator, which may include, but is not limited to, monitoring 
results, review of operation and maintenance procedures, review of 
operation and maintenance records, and inspection of the source.
* * * * *
    (k) Affirmative defense for exceedance of emission limit during 
malfunction. In response to an action to enforce the standards set 
forth in this subpart, the owner or operator may assert an affirmative 
defense to a claim for civil penalties for exceedances of such 
standards that are caused by malfunction, as defined at Sec.  63.2. 
Appropriate penalties may be assessed, however, if the owner or 
operator fails to meet their burden of proving all of the requirements 
in the affirmative defense. The affirmative defense shall not be 
available for claims for injunctive relief.
    (1) To establish the affirmative defense in any action to enforce 
such a limit, the owner or operator must timely meet the notification 
requirements in paragraph (k)(2) of this section, and must prove by a 
preponderance of evidence that:
    (i) The excess emissions:
    (A) Were caused by a sudden, infrequent, and unavoidable failure of 
air pollution control and monitoring equipment, process equipment, or a 
process to operate in a normal or usual manner, and
    (B) Could not have been prevented through careful planning, proper 
design or better operation and maintenance practices; and
    (C) Did not stem from any activity or event that could have been 
foreseen and avoided, or planned for; and
    (D) Were not part of a recurring pattern indicative of inadequate 
design, operation, or maintenance; and
    (ii) Repairs were made as expeditiously as possible when the 
applicable emission limitations were being exceeded. Off-shift and 
overtime labor were used, to the extent practicable to make these 
repairs; and
    (iii) The frequency, amount and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (iv) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, personal injury, or severe property damage; and
    (v) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment and human 
health; and

[[Page 1312]]

    (vi) All emissions monitoring and control systems were kept in 
operation if at all possible, consistent with safety and good air 
pollution control practices; and
    (vii) All of the actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (viii) At all times, the affected source was operated in a manner 
consistent with good practices for minimizing emissions; and
    (ix) A written root cause analysis has been prepared, the purpose 
of which is to determine, correct, and eliminate the primary causes of 
the malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis shall also specify, using best monitoring 
methods and engineering judgment, the amount of excess emissions that 
were the result of the malfunction.
    (2) Notification. The owner or operator of the affected source 
experiencing an exceedance of its emission limit(s) during a 
malfunction shall notify the Administrator by telephone or facsimile 
(FAX) transmission as soon as possible, but no later than two business 
days after the initial occurrence of the malfunction, if it wishes to 
avail itself of an affirmative defense to civil penalties for that 
malfunction. The owner or operator seeking to assert an affirmative 
defense shall also submit a written report to the Administrator within 
45 days of the initial occurrence of the exceedance of the standard in 
this subpart to demonstrate, with all necessary supporting 
documentation, that it has met the requirements set forth in paragraph 
(k)(1) of this section. The owner or operator may seek an extension of 
this deadline for up to 30 additional days by submitting a written 
request to the Administrator before the expiration of the 45 day 
period. Until a request for an extension has been approved by the 
Administrator, the owner or operator is subject to the requirement to 
submit such report within 45 days of the initial occurrence of the 
exceedance.
    15. Section 63.1361 is amended by:
    a. Adding in alphabetical order the definition for ``Affirmative 
defense''.
    b. Correcting a typographical error in the definition of ``Group 1 
process vent'' by Removing the word ``hydogen'' and adding in its place 
the word ``hydrogen'' in the definition of ``Group 1 process vent''
    The addition reads as follows:

Sec.  63.1361  Definitions.

* * * * *
    Affirmative defense means, in the context of an enforcement 
proceeding, a response or defense put forward by a defendant, regarding 
which the defendant has the burden of proof, and the merits of which 
are independently and objectively evaluated in a judicial or 
administrative proceeding.
* * * * *
    16. Section 63.1362 is amended by revising paragraph (i) to read as 
follows:

Sec.  63.1362  Standards.

    (i) Opening of a safety device. The owner or operator that opens a 
safety device, as defined in Sec.  63.1361, is not exempt from 
applicable standards in order to avoid unsafe conditions. If opening a 
safety device results in the failure to meet any applicable standard, 
the owner or operator must still comply with the general duty to 
minimize emissions. If opening a safety device results in a deviation 
or excess emissions, such events must be reported as specified in Sec.  
63.1368(i). If the owner or operator attributes the event to a 
malfunction and intends to assert an affirmative defense, the owner or 
operator is subject to Sec.  63.1360(k).
* * * * *
    17. Section 63.1363 is amended by:
    a. Revising the first sentence of paragraph (b) introductory text;
    b. Adding paragraph (b)(4);
    c. Revising paragraph (g)(4)(v)(A);
    d. Revising paragraphs (h)(1) introductory text and (h)(1)(i);
    e. Adding paragraph (h)(1)(iii);
    f. Adding paragraph (h)(4).
    The additions and revisions read as follows:

Sec.  63.1363  Standards for equipment leaks.

* * * * *
    (b) * * * The owner or operator shall comply with the provisions of 
subpart H of this part as specified in paragraphs (b)(1) through (3) of 
this section and with paragraph (b)(4) of this section for pressure 
relief device monitoring. * * *
* * * * *
    (4) Requirements for pressure relief devices. For pressure relief 
devices, the owner or operator must meet the requirements of this 
paragraph. Any release to the atmosphere from a pressure relief device 
in organic HAP service constitutes a violation of this rule. The owner 
or operator must install, maintain, and operate release indicators as 
specified in paragraphs (b)(4)(i) and (ii) of this section unless the 
pressure relief routes to a closed vent system and control device 
designed and operated in accordance with the requirements of this 
subpart. For any pressure relief devices, the owner or operator must 
comply with the recordkeeping provisions in paragraph (g) of this 
section and the reporting provisions in this paragraph (h) of this 
section. For any release, the owner or operator must submit the report 
specified in paragraph (h)(4) of this section, as described in 
paragraph (b)(4)(iii) of this section.
    (i) A release indicator must be properly installed on each pressure 
relief device in such a way that it will indicate when an emission 
release has occurred.
    (ii) Each indicator must be equipped with an alert system that will 
notify an operator immediately and automatically when the pressure 
relief device is open. The alert must be located such that the signal 
is detected and recognized easily by an operator.
    (iii) For any instance that the release indicator indicates that a 
pressure relief device is open, the owner or operator must notify the 
Administrator that a pressure release has occurred and submit to the 
Administrator the report specified in paragraph (h)(4) of this section. 
This report is required even if the owner or operators elects to follow 
the procedures specified in Sec.  63.1360(k) to establish an 
affirmative defense.
* * * * *
    (g) * * *
    (4) * * *
    (v) * * *
    (A) The owner or operator may develop a written procedure that 
identifies the conditions that justify a delay of repair. The written 
procedures must be maintained at the plant site. Reasons for delay of 
repair may be documented by citing the relevant sections of the written 
procedure.
    (h) * * *
    (1) Each owner or operator of a source subject to this section 
shall submit the reports listed in paragraphs (h)(1)(i) through (iii) 
of this section.
    (i) A Notification of Compliance Status report described in 
paragraph (h)(2) of this section.
* * * * *
    (iii) A pressure relief device deviation report described in 
paragraph (h)(4) of this section.
* * * * *
    (4) Pressure relief device deviation report. If any pressure relief 
device in organic HAP service or any piece of equipment or closed vent 
system has discharged to the atmosphere as specified in paragraph 
(b)(4) of this section, the owner or operator must submit to the 
Administrator in the next Periodic Report:
    (i) The source, nature, and cause of the discharge.
    (ii) The date, time, and duration of the discharge.

[[Page 1313]]

    (iii) An estimate of the quantity of total organic HAP emitted 
during the discharge and the method used for determining this quantity.
    (iv) The actions taken to prevent this discharge.
    (v) The measures adopted to prevent future such discharges.
    18. Section 63.1365 is amended by:
    a. Revising paragraph (b) introductory text;
    b. Removing and reserving paragraph (h)(3).
    The revision reads as follows:

Sec.  63.1365  Test methods and initial compliance procedures.

* * * * *
    (b) Test methods and conditions. When testing is conducted to 
measure emissions from an affected source, the test methods specified 
in paragraphs (b)(1) through (9) of this section shall be used. 
Compliance and performance tests shall be performed under such 
conditions as the Administrator specifies to the owner or operator 
based on representative performance of the affected source for the 
period being tested and as specified in paragraphs (b)(10) and (11) of 
this section. Upon request, the owner or operator shall make available 
to the Administrator such records as may be necessary to determine the 
conditions of performance tests.
* * * * *

Sec.  63.1366  [Amended]

    19. Section 63.1366 is amended by removing and reserving paragraph 
(b)(8)(iv).
    20. Section 63.1367 is amended by revising paragraph (a)(3) to read 
as follows:

Sec.  63.1367  Recordkeeping requirements.

    (a) * * *
    (3) Records of malfunctions. (i) The owner or operator of an 
affected source subject to this subpart shall maintain records of the 
occurrence and duration of each malfunction of operation (i.e., process 
equipment), air pollution control equipment, or monitoring equipment, 
and an estimate of the excess emissions released.
    (ii) The owner or operator shall maintain records of actions taken 
during periods of malfunction to minimize emissions in accordance with 
Sec.  63.1360(e)(4), including corrective actions to restore 
malfunctioning process and air pollution control and monitoring 
equipment to its normal or usual manner of operation.
* * * * *
    21. Section 63.1368 is amended by:
    a. Revising paragraph (i);
    b. Adding paragraph (p).
    The revisions and addition read as follows:

Sec.  63.1368  Reporting requirements.

* * * * *
    (i) Reports of malfunctions. For the purposes of this subpart, 
reports of malfunctions shall be submitted on the same schedule as the 
Periodic reports required under paragraph (g) of this section instead 
of the schedule specified in Sec.  63.10(d)(5)(i) of subpart A of this 
part. If a malfunction occurred during the reporting period, the report 
must include the number, duration, excess emissions estimate, and a 
brief description for each type of malfunction which occurred during 
the reporting period and which caused or may have caused any applicable 
emission limitation to be exceeded. The report must also include a 
description of actions taken by an owner or operator during a 
malfunction of an affected source to minimize emissions in accordance 
with Sec.  63.1360(e)(4), including actions taken to correct a 
malfunction.
* * * * *
    (p) Electronic reporting. (1) Within 60 days after the date of 
completing each performance test (defined in Sec.  63.2) as required in 
this subpart, the owner or operator must transmit the results of the 
performance tests required by this subpart to EPA's WebFIRE database by 
using the Compliance and Emissions Data Reporting Interface (CEDRI) 
that is accessed through EPA's Central Data Exchange (CDX) (see http://www.epa.gov/cdx). Performance test data must be submitted in the file 
format generated through use of EPA's Electronic Reporting Tool (ERT) 
(see http://www.epa.gov/ttn/chief/ert/index.html). Only data collected 
using test methods on the ERT Web site are subject to this requirement 
for submitting reports electronically to WebFIRE. Owners or operators 
who claim that some of the information being submitted for performance 
tests is confidential business information (CBI) must submit a complete 
ERT file including information claimed to be CBI on a compact disk or 
other commonly used electronic storage media (including, but not 
limited to, flash drives) to EPA. The electronic media must be clearly 
marked as CBI and mailed to U.S. EPA/OAPQS/CORE CBI Office, Attention: 
WebFIRE Administrator, MD C404-02, 4930 Old Page Rd., Durham, NC 27703. 
The same ERT file with the CBI omitted must be submitted to EPA via CDX 
as described earlier in this paragraph. At the discretion of the 
delegated authority, you must also submit these reports, including the 
confidential business information, to the delegated authority in the 
format specified by the delegated authority.
    (2) All reports required by this subpart not subject to the 
requirements in this paragraph (p) must be sent to the Administrator at 
the appropriate address listed in Sec.  63.13. The Administrator or the 
delegated authority may request a report in any form suitable for the 
specific case (e.g., by commonly used electronic media such as Excel 
spreadsheet, on CD or hard copy). The Administrator retains the right 
to require submittal of reports subject to this paragraph (p) in paper 
format.
    22. Table 1 to subpart MMM of part 63 is amended by:
    a. Removing entry 63.6(e);
    b. Adding entries 63.6(e)(1)(i), 63.6(e)(1)(ii), 63.6(e)(1)(iii), 
and 63.6(e)(3);
    c. Removing entry 63.6(f);
    d. Adding entries 63.6(f)(1) and 63.6(f)(2)-(3);
    e. Revising entry 63.7(e)(1);
    f. Removing entry 63.8(b)(3)-(c)(3);
    g. Adding entries 63.8(b)(3), 63.8(c)(1)(i), 63.8(c)(1)(ii), 
63.8(c)(1)(iii), and 63.8(c)(2)-(3);
    h. Revising entry 63.8(d)-(f)(3);
    i. Removing entry 63.10(c);
    j. Adding entries 63.10(c)(1)-(8), 63.10(c)(10)-(11), 63.10(c)(12)-
(14), and 63.10(c)(15);
    k. Revising entry 63.10(d)(5).
    The revisions and additions read as follows:

 Table 1 to Subpart MMM of Part 63--General Provisions Applicability to
                               Subpart MMM
------------------------------------------------------------------------
                                    Applies to
    Reference to subpart A         subpart MMM          Explanation
------------------------------------------------------------------------
 
                              * * * * * * *
63.6(e)(1)(i).................  No...............  See Sec.
                                                    63.1360(e)(4) for
                                                    general duty
                                                    requirement.
Sec.   63.6(e)(1)(ii).........  No...............

[[Page 1314]]

 
Sec.   63.6(e)(1)(iii)........  Yes..............
Sec.   63.6(e)(3).............  No...............
Sec.   63.6(f)(1).............  No...............
Sec.   63.6(f)(2)-(3).........  Yes..............
 
                              * * * * * * *
Sec.   63.7(e)(1).............  No...............  See Sec.
                                                    63.1365(b).
 
                              * * * * * * *
Sec.   63.8(b)(3).............  Yes..............
Sec.   63.8(c)(1)(i)..........  No...............
Sec.   63.8(c)(1)(ii).........  Yes..............
Sec.   63.8(c)(1)(iii)........  No...............
Sec.   63.8(c)(2)-(3).........  Yes..............
 
                              * * * * * * *
Sec.   63.8(d)-(f)(3).........  Yes..............  Except the last
                                                    sentence of Sec.
                                                    63.8(d)(3), which
                                                    refers to an SSM
                                                    plan. SSM plans are
                                                    not required.
 
                              * * * * * * *
Sec.   63.10(c)(1)-(8)........  Yes..............
Sec.   63.10(c)(10)-(11)......  No...............  See Sec.
                                                    63.1367(a)(3) for
                                                    malfunction
                                                    recordkeeping
                                                    requirements.
Sec.   63.10(c)(12)-(14)......  Yes..............
Sec.   63.10(c)(15)...........  No...............
 
                              * * * * * * *
Sec.   63.10(d)(5)............  No...............  See Sec.   63.1368(i)
                                                    for malfunction
                                                    reporting
                                                    requirements.
 
                              * * * * * * *
------------------------------------------------------------------------

* * * * *

Subpart PPP--[Amended]

    23. Section 63.1420 is amended by:
    a. Revising paragraphs (a)(4) introductory text and (a)(4)(iv);
    b. Revising paragraphs (c)(1), (d) introductory text, and the 
heading for paragraph (e(8);
    c. Revising paragraph (h) and;
    d. Adding paragraph (i).
    The revisions and addition read as follows:

Sec.  63.1420  Applicability and designation of affected sources.

    (a) * * *
    (4) The affected source also includes the emission points and 
components specified in paragraphs (a)(4)(i) through (vi) of this 
section that are associated with a PMPU (or a group of PMPUs) making up 
an affected source, as defined in Sec.  63.1423.
* * * * *
    (iv) Components required by or utilized as a method of compliance 
with this subpart which may include control techniques and recovery 
devices.
* * * * *
    (c) * * *
    (1) Components and equipment that do not contain organic HAP or 
that contain organic HAP as impurities only and are located at a PMPU 
that is part of an affected source.
* * * * *
    (d) Processes excluded from the affected source. The processes 
specified in paragraphs (d)(1) through (3) of this section are not part 
of the affected source and are not subject to the requirements of both 
this subpart and subpart A of this part.
* * * * *
    (e) * * *
    (8) Requirements for flexible process units that are not PMPU. * * 
*
* * * * *
    (h) Applicability of this subpart. (1) The emission limitations set 
forth in this subpart and the emission limitations referred to in this 
subpart shall apply at all times except during periods of nonoperation 
of the affected source (or specific portion thereof) resulting in 
cessation of the emissions to which this subpart applies.
    (2) The emission limitations set forth in 40 CFR part 63, subpart 
H, as referred to in the equipment leak provisions in Sec.  63.1434, 
shall apply at all times except during periods of non-operation of the 
affected source (or specific portion thereof) in which the lines are 
drained and depressurized resulting in cessation of the emissions to 
which Sec.  63.1434 applies.
    (3) The owner or operator shall not shut down items of equipment 
that are required or utilized for compliance with this subpart during 
times when emissions (or, where applicable, wastewater streams or 
residuals) are being routed to such items of equipment if the shutdown 
would contravene requirements applicable to such items of equipment.
    (4) General duty. At all times, the owner or operator must operate 
and maintain any affected source, including associated air pollution 
control equipment and monitoring equipment, in a manner consistent with 
safety and good air pollution control practices for minimizing 
emissions. Determination of whether such operation and maintenance 
procedures are being used will be based on information available to the 
Administrator, which may include, but is not limited to, monitoring 
results, review of operation and maintenance procedures, review of 
operation and maintenance records, and inspection of the source.
    (i) Affirmative defense for exceedance of emission limit during 
malfunction. In response to an action to enforce the standards set 
forth in this subpart, the owner or operator may assert an affirmative 
defense to a claim for civil penalties for exceedances of such 
standards that are caused by malfunction, as defined at Sec.  63.2. 
Appropriate penalties may be assessed, however, if the owner or 
operator fails

[[Page 1315]]

to meet their burden of proving all of the requirements in the 
affirmative defense. The affirmative defense shall not be available for 
claims for injunctive relief.
    (1) To establish the affirmative defense in any action to enforce 
such a limit, the owner or operator must timely meet the notification 
requirements in paragraph (i)(2) of this section, and must prove by a 
preponderance of evidence that:
    (i) The excess emissions:
    (A) Were caused by a sudden, infrequent, and unavoidable failure of 
air pollution control and monitoring equipment, process equipment, or a 
process to operate in a normal or usual manner; and
    (B) Could not have been prevented through careful planning, proper 
design or better operation and maintenance practices; and
    (C) Did not stem from any activity or event that could have been 
foreseen and avoided, or planned for; and
    (D) Were not part of a recurring pattern indicative of inadequate 
design, operation, or maintenance; and
    (ii) Repairs were made as expeditiously as possible when the 
applicable emission limitations were being exceeded. Off-shift and 
overtime labor were used, to the extent practicable to make these 
repairs; and
    (iii) The frequency, amount and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (iv) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, personal injury, or severe property damage; and
    (v) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment and human 
health; and
    (vi) All emissions monitoring and control systems were kept in 
operation if at all possible, consistent with safety and good air 
pollution control practices; and
    (vii) All of the actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (viii) At all times, the affected source was operated in a manner 
consistent with good practices for minimizing emissions; and
    (ix) A written root cause analysis has been prepared, the purpose 
of which is to determine, correct, and eliminate the primary causes of 
the malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis shall also specify, using best monitoring 
methods and engineering judgment, the amount of excess emissions that 
were the result of the malfunction.
    (2) Notification. The owner or operator of the affected source 
experiencing an exceedance of its emission limit(s) during a 
malfunction shall notify the Administrator by telephone or facsimile 
(FAX) transmission as soon as possible, but no later than two business 
days after the initial occurrence of the malfunction, if it wishes to 
avail itself of an affirmative defense to civil penalties for that 
malfunction. The owner or operator seeking to assert an affirmative 
defense shall also submit a written report to the Administrator within 
45 days of the initial occurrence of the exceedance of the standard in 
this subpart to demonstrate, with all necessary supporting 
documentation, that it has met the requirements set forth in paragraph 
(i)(1) of this section. The owner or operator may seek an extension of 
this deadline for up to 30 additional days by submitting a written 
request to the Administrator before the expiration of the 45 day 
period. Until a request for an extension has been approved by the 
Administrator, the owner or operator is subject to the requirement to 
submit such report within 45 days of the initial occurrence of the 
exceedance.
    24. Section 63.1423 is amended by:
    a. Removing the phrase ``Start-up, shutdown, and malfunction plan 
(subpart F)'' in paragraph (a); and
    b. Adding the term ``Affirmative defense'' in alphabetical order to 
paragraph (b) to read as follows:

Sec.  63.1423  Definitions.

* * * * *
    (b) * * *
    Affirmative defense means, in the context of an enforcement 
proceeding, a response or defense put forward by a defendant, regarding 
which the defendant has the burden of proof, and the merits of which 
are independently and objectively evaluated in a judicial or 
administrative proceeding.
* * * * *
    25. Section 63.1430 is amended by revising paragraph (d)(2)(i) to 
read as follows:

Sec.  63.1430  Process vent reporting and recordkeeping requirements.

* * * * *
    (d) * * *
    (2) * * *
    (i) Monitoring data recorded during periods of monitoring system 
breakdowns, repairs, calibration checks, and zero (low-level) and high-
level adjustments shall not be included in computing the daily 
averages. In addition, monitoring data recorded during periods of non-
operation of the process (or specific portion thereof) resulting in 
cessation of organic HAP emissions shall not be included in computing 
the daily averages.
* * * * *
    26. Section 63.1434 is amended by revising paragraphs (c) to read 
as follows:

Sec.  63.1434  Equipment leak provisions.

* * * * *
    (c) Requirements for pressure relief devices. For pressure relief 
devices, the owner or operator must meet the requirements of this 
paragraph. Any release to the atmosphere from a pressure relief device 
in organic HAP service constitutes a violation of this rule. The owner 
or operator must install, maintain, and operate release indicators as 
specified in paragraphs (c)(1) and (2) of this section unless the 
pressure relief routes to a closed vent system and control device 
designed and operated in accordance with the requirements of this 
subpart. For any pressure relief devices, the owner or operator must 
comply with the recordkeeping and reporting provisions in Sec.  
63.1439(c) and (e)(9). For any release, the owner or operator must 
submit the report specified in Sec.  63.1439(e)(9), as described in 
paragraph (c)(3) of this section.
    (1) A release indicator must be properly installed on each pressure 
relief device in such a way that it will indicate when an emission 
release has occurred.
    (2) Each indicator must be equipped with an alert system that will 
notify an operator immediately and automatically when the pressure 
relief device is open. The alert must be located such that the signal 
is detected and recognized easily by an operator.
    (3) For any instance that the release indicator indicates that a 
pressure relief device is open, the owner or operator must notify the 
Administrator that a pressure release has occurred and submit to the 
Administrator the report specified in Sec.  63.1439(e)(9). This report 
is required even if the owner or operator elects to follow the 
procedures specified in Sec.  63.1420(k) to establish an affirmative 
defense.
* * * * *
    27. Section 63.1437 is amended by revising paragraph (a) 
introductory text and the first sentence of (a)(1) introductory text to 
read as follows:

[[Page 1316]]

Sec.  63.1437  Additional requirements for performance testing.

    (a) Performance testing shall be conducted in accordance with Sec.  
63.7(a)(1), (a)(3), (d), (e)(2), (e)(4), (g), and (h), with the 
exceptions specified in paragraphs (a)(1) through (4) of this section 
and the additions specified in paragraph (b) of this section. 
Performance tests shall be conducted under such conditions as the 
Administrator specifies to the owner or operator based on 
representative performance of the affected source for the period being 
tested. Upon request, the owner or operator shall make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests.
    (1) Performance tests shall be conducted according to the general 
provisions' performance testing requirements in Sec.  63.7(e)(2), 
except that for all emission sources except process vents from batch 
unit operations, performance tests shall be conducted during maximum 
representative operating conditions for the process achievable during 
one of the time periods described in paragraph (a)(1)(i) of this 
section, without causing any of the situations described in paragraph 
(a)(1)(ii) or (iii) of this section to occur. * * *
* * * * *
    28. Section 63.1438 is amended by:
    a. Revising paragraphs (e)(1) introductory text and (e)(2);
    b. Removing and reserving paragraphs (f)(1)(v)(A) through (C), 
(f)(3)(ii)(B)(1) through (3), and (g).
    The revisions read as follows:

Sec.  63.1438  Parameter monitoring levels and excursions.

    (e) * * *
    (1) Each excursion, as defined in paragraphs (f)(1)(i), 
(f)(2)(i)(A), (f)(2)(ii), (f)(3)(i), and (f)(4) of this section, 
constitutes a violation of the provisions of this subpart in accordance 
with paragraph (e)(1)(i), (ii), or (iii) of this section.
* * * * *
    (2) Each excursion, as defined in paragraphs (f)(1)(ii), 
(f)(1)(iii), (f)(2)(i)(B), and (f)(3)(ii) of this section constitutes a 
violation of the operating limit.
* * * * *
    29. Section 63.1439 is amended by:
    a. Revising paragraph (b)(1);
    b. Removing and reserving paragraphs (d)(7)(ii) through (iv);
    c. Revising paragraphs (e) introductory text, (e)(4)introductory 
text, and (e)(4)(v);
    d. Removing and reserving paragraph (e)(4)(vi);
    e. Revising paragraph (e)(4)(vii)(B);
    f. Revising paragraphs (e)(6)(iii)(E), (e)(6)(viii)(A)(1), and 
(e)(6)(viii)(D);
    g. Adding paragraphs (e)(9) and (10);
    h. Revising the first sentence of paragraph (h)(1)(i);
    i. Removing and reserving paragraph (h)(1)(ii)(C);
    j. Revising paragraph (h)(1)(iii); and
    k. Revising paragraph (h)(2)(iii) and (iv).
    The additions and revisions read as follows:

Sec.  63.1439  General recordkeeping and reporting provisions.

* * * * *
    (b) * * *
    (1) Malfunction recordkeeping and reporting. (i) Records of 
malfunctions. The owner or operator shall keep the records specified in 
paragraphs (b)(1)(i)(A) and (B) of this section.
    (A) Records of the occurrence and duration of each malfunction of 
operation of process equipment or combustion, recovery, or recapture 
devices or continuous monitoring systems used to comply with this 
subpart, and an estimate of the excess emissions released.
    (B) Records of actions taken during periods of malfunction to 
minimize emissions in accordance with Sec.  63.1420(h)(4), including 
corrective actions to restore malfunctioning process and air pollution 
control and monitoring equipment to its normal or usual manner of 
operation.
    (ii) Reports of malfunctions. For the purposes of this subpart, 
reports of malfunctions shall be submitted on the same schedule as the 
Periodic Reports required under paragraph (e)(6) of this section. If a 
malfunction occurred during the reporting period, the report must 
include the number, duration, excess emissions estimate, and a brief 
description for each type of malfunction which occurred during the 
reporting period and which caused or may have caused any applicable 
emission limitation to be exceeded. The report must also include a 
description of actions taken by an owner or operator during a 
malfunction of an affected source to minimize emissions in accordance 
with Sec.  63.1420(h)(4), including actions taken to correct a 
malfunction.
* * * * *
    (e) Reporting and notification. In addition to the reports and 
notifications required by 40 CFR part 63, subpart A, as specified in 
this subpart, the owner or operator of an affected source shall prepare 
and submit the reports listed in paragraphs (e)(3) through (10) of this 
section, as applicable. All reports required by this subpart, and the 
schedule for their submittal, are listed in Table 8 of this subpart.
* * * * *
    (4) Precompliance Report. The owner or operator of an affected 
source requesting an extension for compliance; requesting approval to 
use alternative monitoring parameters, alternative continuous 
monitoring and recordkeeping, or alternative controls; or requesting 
approval to establish parameter monitoring levels according to the 
procedures contained in Sec.  63.1438(c) or (d) shall submit a 
Precompliance Report according to the schedule described in paragraph 
(e)(4)(i) of this section. The Precompliance Report shall contain the 
information specified in paragraphs (e)(4)(ii) through (viii) of this 
section, as appropriate.
* * * * *
    (v) The owner or operator shall report the intent to use an 
alternative emissions standard to comply with the provisions of this 
subpart in the Precompliance Report. The Administrator may deem an 
alternative emissions standard to be equivalent to the standard 
required by the subpart, under the procedures outlined in the General 
Provisions' requirements for use of an alternative nonopacity emission 
standard, in Sec.  63.6(g).
* * * * *
    (vii) * * *
    (B) Supplements to the Precompliance Report may be submitted to 
request approval to use alternative monitoring parameters, as specified 
in paragraph (e)(4)(iii) of this section; to use alternative continuous 
monitoring and recordkeeping, as specified in paragraph (e)(4)(iv) of 
this section; or to use alternative controls, as specified in paragraph 
(e)(4)(v) of this section.
* * * * *
    (6) * * *
    (iii) * * *
    (E) The information in paragraph (b)(1)(ii) of this section for 
reports of malfunctions.
* * * * *
    (viii) * * *
    (A) * * *
    (1) A combustion, recovery, or recapture device for a particular 
emission point or process section has one or more excursions, as 
defined in Sec.  63.1438(f) for a semiannual reporting period; or
* * * * *
    (D) After quarterly reports have been submitted for an emission 
point for 1 year without one or more excursions

[[Page 1317]]

occurring (during that year), the owner or operator may return to 
semiannual reporting for the emission point or process section
* * * * *
    (9) Pressure relief device deviation report. If any pressure relief 
device in organic HAP service or any piece of equipment or closed vent 
system has discharged to the atmosphere as specified in Sec.  
63.1434(c), the owner or operator must submit to the Administrator in 
the next Periodic Report:
    (i) The source, nature, and cause of the discharge.
    (ii) The date, time, and duration of the discharge.
    (iii) An estimate of the quantity of total organic HAP emitted 
during the discharge and the method used for determining this quantity.
    (iv) The actions taken to prevent this discharge.
    (v) The measures adopted to prevent future such discharges.
    (10) Electronic reporting. (i) Within 60 days after the date of 
completing each performance test (defined in Sec.  63.2) as required in 
this subpart, the owner or operator must transmit the results of the 
performance tests required by this subpart to EPA's WebFIRE database by 
using the Compliance and Emissions Data Reporting Interface (CEDRI) 
that is accessed through EPA's Central Data Exchange (CDX) (see http://www.epa.gov/cdx). Performance test data must be submitted in the file 
format generated through use of EPA's Electronic Reporting Tool (ERT) 
(see http://www.epa.gov/ttn/chief/ert/index.html). Only data collected 
using test methods on the ERT Web site are subject to this requirement 
for submitting reports electronically to WebFIRE. Owners or operators 
who claim that some of the information being submitted for performance 
tests is confidential business information (CBI) must submit a complete 
ERT file including information claimed to be CBI on a compact disk or 
other commonly used electronic storage media (including, but not 
limited to, flash drives) to EPA. The electronic media must be clearly 
marked as CBI and mailed to U.S. EPA/OAPQS/CORE CBI Office, Attention: 
WebFIRE Administrator, MD C404-02, 4930 Old Page Rd., Durham, NC 27703. 
The same ERT file with the CBI omitted must be submitted to EPA via CDX 
as described earlier in this paragraph. At the discretion of the 
delegated authority, you must also submit these reports, including the 
confidential business information, to the delegated authority in the 
format specified by the delegated authority.
    (ii) All reports required by this subpart not subject to the 
requirements in paragraph (e)(10) of this section must be sent to the 
Administrator at the appropriate address listed in Sec.  63.13. The 
Administrator or the delegated authority may request a report in any 
form suitable for the specific case (e.g., by commonly used electronic 
media such as Excel spreadsheet, on CD or hard copy). The Administrator 
retains the right to require submittal of reports subject to paragraph 
(e)(10)(i) and (ii) of this section in paper format.
* * * * *
    (h) * * *
    (1) * * *
    (i) The monitoring system is capable of detecting unrealistic or 
impossible data during periods of operation (e.g., a temperature 
reading of -200 [deg]C on a boiler), and will alert the operator by 
alarm or other means. * * *
* * * * *
    (iii) The monitoring system is capable of detecting unchanging data 
during periods of operation, except in circumstances where the presence 
of unchanging data are the expected operating condition based on past 
experience (e.g., pH in some scrubbers), and will alert the operator by 
alarm or other means. The owner or operator shall record the 
occurrence. All instances of the alarm or other alert in an operating 
day constitute a single occurrence.
    (2) * * *
    (iii) The owner or operator shall retain the records specified in 
paragraph (h)(1) of this section, for the duration specified in this 
paragraph (h). For any calendar week, if compliance with paragraphs 
(h)(1)(i) through (iv) of this section does not result in retention of 
a record of at least one occurrence or measured parameter value, the 
owner or operator shall record and retain at least one parameter value 
during a period of operation.
    (iv) For the purposes of this paragraph (h), an excursion means 
that the daily average of monitoring data for a parameter is greater 
than the maximum, or less than the minimum established value.
    30. Table 1 to Subpart PPP of part 63 is amended by:
    a. Revising entries 63.6(e)(1)(i) and 63.6(e)(1)(ii);
    b. Adding entry 63.6(e)(3);
    c. Removing entries 63.6(e)(3)(i) through 63.6(e)(3)(ix);
    d. Revising entries 63.6(f)(1), 63.7(e)(1), 63.8(c)(1)(i), 
63.8(c)(1)(iii), and 63.10(d)(5);
    e. Removing entries 63.10(d)(5)(i) and 63.10(d)(5)(ii).
    The revisions and addition read as follows:

 Table 1 of Subpart PPP of Part 63--Applicability of General Provisions
                     to Subpart PPP Affected Sources
------------------------------------------------------------------------
                                    Applies to
           Reference               subpart PPP          Explanation
------------------------------------------------------------------------
 
                              * * * * * * *
63.6(e)(1)(i).................  No...............  See Sec.
                                                    63.1420(h)(4) for
                                                    general duty
                                                    requirement.
63.6(e)(1)(ii)................  No.
 
                              * * * * * * *
63.6(e)(3)....................  No...............
63.6(f)(1)....................  No.
 
                              * * * * * * *
63.7(e)(1)....................  No...............  See Sec.  Sec.
                                                    63.1436(h) and
                                                    63.1437(a).
 
                              * * * * * * *
63.8(c)(1)(i).................  No.
 
                              * * * * * * *
63.8(c)(1)(iii)...............  No.

[[Page 1318]]

 
 
                              * * * * * * *
63.10(d)(5)...................  No.
 
                              * * * * * * *
------------------------------------------------------------------------

    31. Table 2 to Subpart PPP of part 63 is amended by revising the 
title to read as follows:

Table 2 of Subpart PPP of Part 63--Applicability of HON Provisions to 
Subpart PPP Affected Sources

* * * * *
[FR Doc. 2011-32934 Filed 1-6-12; 8:45 am]
BILLING CODE 6560-50-P