```

[Federal Register Volume 78, Number 213 (Monday, November 4, 2013)]
[Proposed Rules]
[Pages 66107-66138]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-24276]

[[Page 66107]]

Vol. 78

Monday,

No. 213

November 4, 2013

Part II

Environmental Protection Agency

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40 CFR Part 63

National Emissions Standards for Hazardous Air Pollutants Residual Risk 
and Technology Review for Flexible Polyurethane Foam Production; 
Proposed Rule

Federal Register / Vol. 78 , No. 213 / Monday, November 4, 2013 / 
Proposed Rules

[[Page 66108]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2012-0510; FRL-9900-94-OAR]
RIN 2060-AR58

National Emissions Standards for Hazardous Air Pollutants 
Residual Risk and Technology Review for Flexible Polyurethane Foam 
Production

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The EPA is proposing amendments to the National Emissions 
Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam 
Production to address the results of the residual risk and technology 
review. In light of our review, we are proposing amendments that would 
prohibit the use of hazardous air pollutant-based auxiliary blowing 
agents for slabstock foam production facilities. In addition, the EPA 
is proposing amendments to correct and clarify regulatory provisions 
related to emissions during periods of startup, shutdown and 
malfunction; to add provisions for affirmative defense; to add 
requirements for reporting of performance testing through the 
Electronic Reporting Tool; to revise compliance dates for applicable 
proposed actions; to clarify the leak detection methods allowed for 
diisocyanate storage vessels at slabstock foam production facilities; 
and to revise the rule to add a schedule for delay of leak repairs for 
valves and connectors.

DATES: 
    Comments. Comments must be received on or before December 4, 2013. 
A copy of comments on the information collection provisions should be 
submitted to the Office of Management and Budget (OMB) on or before 
December 4, 2013.
    Public Hearing. If anyone contacts the EPA requesting a public 
hearing by November 14, 2013, the public hearing will be held on 
November 20, 2013, from 10:00 a.m. to 4:00 p.m. on the EPA campus at 
109 T.W. Alexander Drive in Research Triangle Park, North Carolina. If 
EPA holds a public hearing, the EPA will keep the record of the hearing 
open for 30 days after completion of the hearing to provide an 
opportunity for submission of rebuttal and supplementary information.

ADDRESSES: Submit your comments, identified by Docket ID Number EPA-HQ-
OAR-2012-0510, by one of the following methods:
    http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     Email: a-and-r-Docket@epa.gov, Attention Docket ID Number 
EPA-EPA-HQ-OAR-2012-0510.
     Fax: (202) 566-9744, Attention Docket ID Number EPA-HQ-
OAR-2012-0510.
     Mail: U.S. Postal Service, send comments to: EPA Docket 
Center, EPA West (Air Docket), Attention Docket ID Number EPA-HQ-OAR-
2012-0510, 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, 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 Number EPA-HQ-OAR-2012-0510. 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 Number EPA-HQ-OAR-
2012-0510. 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 not include special characters or 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/dockets.
    Docket. The EPA has established a docket for this rulemaking under 
Docket ID Number EPA-HQ-OAR-2012-0510. All documents in the docket are 
listed in the 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 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 anyone contacts the EPA requesting a public 
hearing by November 14, 2013, the public hearing will be held on 
November 20, 2013, from 10:00 a.m. to 4:00 p.m. on the EPA campus at 
109 T.W. Alexander Drive in Research Triangle Park, North Carolina. 
Persons interested in presenting oral testimony or inquiring as to 
whether a public hearing will be held should contact Ms. Pamela 
Garrett, Sector Policies and Programs Division (D243-01), Office of Air 
Quality Planning and Standards, U.S. Environmental Protection Agency, 
Research Triangle Park, North Carolina 27711; telephone number: (919) 
541-7966; fax number: (919) 541-5450; and email address: 
garrett.pamela@epa.gov.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Ms. Kaye Whitfield, Sector Policies and Programs 
Division (D243-02), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711; telephone number: (919) 541-2509; fax number: (919) 541-5450; 
and email address: whitfield.kaye@epa.gov. For specific information 
regarding the risk modeling

[[Page 66109]]

methodology, contact Mr. Chris Sarsony, Health and Environmental 
Impacts Division (C539-02), Office of Air Quality Planning and 
Standards, U.S. Environmental Protection Agency, Research Triangle 
Park, North Carolina 27711; telephone number: (919) 541-4843; fax 
number: (919) 541-0840; and email address: sarsony.chris@epa.gov. For 
information about the applicability of the National Emission Standards 
for Hazardous Air Pollutants (NESHAP) to a particular entity, contact 
Mr. Scott Throwe, Office of Enforcement and Compliance Assurance; 
telephone number: (202) 564-7013; fax number: (202) 564-0050; and email 
address: throwe.scott@epa.gov.

SUPPLEMENTARY INFORMATION: 

Preamble Acronyms and Abbreviations

    This preamble includes several acronyms and terms used to describe 
industrial processes, data inventories and risk modeling. While this 
list may not be exhaustive, to ease the reading of this preamble and 
for reference purposes, the EPA defines the following terms and 
acronyms here:

ABA auxiliary blowing agent
AEGL acute exposure guideline levels
AERMOD air dispersion model used by the HEM-3 model
BAAQMD Bay Area Air Quality Management District
CAA Clean Air Act
CalEPA California EPA
CBI Confidential Business Information
CDX Central Data Exchange
CEDRI Compliance and Emissions Data Reporting Interface
CFR Code of Federal Regulations
EIS Emission Inventory System
EPA Environmental Protection Agency
ERPG Emergency Response Planning Guidelines
ERT Electronic Reporting Tool
FPUF Flexible Polyurethane Foam
FR Federal Register
HAP hazardous air pollutants
HCl hydrogen chloride
HEM-3 Human Exposure Model, Version 1.1.0
HI hazard index
HF hydrogen fluoride
HQ hazard quotient
ICR information collection request
IRIS Integrated Risk Information System
kg kilogram
km kilometer
lb pound
LDAR leak detection and repair
MACT maximum achievable control technology
MACT Code Code within the National Emissions Inventory used to 
identify processes included in a source category
mg/kg-day milligrams per kilogram per day
mg/m\3\ milligrams per cubic meter
MIR maximum individual risk
NAICS North American Industry Classification System
NEI National Emissions Inventory
NESHAP National Emissions Standards for Hazardous Air Pollutants
NRC National Research Council
NRDC Natural Resources Defense Council
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
PB-HAP hazardous air pollutants known to be persistent and bio-
accumulative in the environment
POM polycyclic organic matter
PFA Polyurethane Foam Association
ppm parts per million
QA quality assurance
REL reference exposure level
RCO recuperative thermal oxidizer
RfC reference concentration
RfD reference dose or daily oral exposure
RTO regenerative thermal oxidizer
RTR residual risk and technology review
SAB Science Advisory Board
SBA Small Business Administration
S/L/Ts State, local, and tribal air pollution control agencies
SOP standing operating procedures
SSM startup, shutdown and malfunction
TOSHI target organ-specific hazard index
tpy tons per year
TRI Toxics Release Inventory
TRIM Total Risk Integrated Methodology
TTN Technology Transfer Network
UF uncertainty factors
[micro]g/m\3\ microgram per cubic meter
UMRA Unfunded Mandates Reform Act
URE unit risk estimate
VCS voluntary consensus standards
WWW world wide web
    Organization of this Document. The information in this preamble is 
organized as follows:

I. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related 
information?
    C. What should I consider as I prepare my comments for the EPA?
II. Background
    A. What is the statutory authority for this action?
    B. What is this source category and how do the MACT standards 
regulate its HAP emissions?
    C. What data collection activities were conducted to support 
this action?
III. Analytical Procedures
    A. How did we estimate post-MACT risks posed by the source 
category?
    B. How did we consider the risk results in making decisions for 
this proposal?
    C. How did we perform the technology review?
    D. What other analyses and reviews were conducted in support of 
this proposal and how did we conduct those analyses and reviews?
IV. Analytical Results and Proposed Decisions
    A. What are the results of the risk assessment and analyses?
    B. What are our proposed decisions regarding risk acceptability, 
ample margin of safety and adverse environmental effects?
    C. What are the results and proposed decisions based on our 
technology review?
    D. What other actions are we proposing?
    E. What compliance dates are we proposing?
V. 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?
VI. Request for Comments
VII. Submitting Data Corrections
VIII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
I. National Technology Transfer and Advancement Act
J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

I. General Information

A. Does this action apply to me?

    Table 1 of this preamble lists the industrial source category that 
is the subject of this proposal. Table 1 is not intended to be 
exhaustive but rather to provide a guide for readers regarding the 
entities that this proposed action is likely to affect. The proposed 
standards, once finalized, will be directly applicable to the affected 
sources. One federal entity is affected by this proposed action, and no 
state, local or tribal government entities are affected by this 
proposed action. As defined in the ``Initial List of Categories of 
Sources Under Section 112(c)(1) of the Clean Air Act Amendments of 
1990'' (see 57 FR 31576, July 16, 1992), the ``Flexible Polyurethane 
Foam Production'' source category is any facility engaged in the

[[Page 66110]]

manufacture of foam made from a polymer containing a plurality of 
carbamate linkages in the chain backbone (polyurethane).\1\
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    \1\ U.S. EPA, 1992. Documentation for Developing the Initial 
Source Category List--Final Report. EPA-450/3-91-030.

Table 1--NESHAP and Industrial Source Category Affected by This Proposed
                                 Action
------------------------------------------------------------------------
                                                             NAICS code
         Source category                   NESHAP                \a\
------------------------------------------------------------------------
Flexible Polyurethane Foam        Flexible Polyurethane          326150
 Production.                       Foam Production.
------------------------------------------------------------------------
\a\ North American Industry Classification System

B. 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 action is available on the Internet through the EPA's Technology 
Transfer Network (TTN) Web site, a forum for information and technology 
exchange in various areas of air pollution control. Following signature 
by the EPA Administrator, the EPA will post a copy of this proposed 
action on the TTN's policy and guidance page for newly proposed or 
promulgated rules at: http://www.epa.gov/ttn/oarpg/t3pfpr.html. 
Following publication in the Federal Register, the EPA will post the 
Federal Register version of the proposal and key technical documents on 
the project Web site: http://www.epa.gov/ttn/atw/foam/foampg.html. 
Information on the overall residual risk and technology review (RTR) 
program is available at the following Web site: http://www.epa.gov/ttn/atw/rrisk/rtrpg.html.

C. 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 comments that includes information claimed 
as CBI, you must submit a copy of the comments that does not contain 
the information claimed as CBI 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 Code of Federal Regulations (CFR) part 2. Send or deliver 
information identified as CBI only to the following address: Roberto 
Morales, OAQPS Document Control Officer (C404-02), OAQPS, U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711, Attention Docket ID Number EPA-HQ-OAR-2012-0510.

II. Background

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) requires 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, the technology-based NESHAP 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 reflect 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 pollutant, 
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 section 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 floor for existing sources 
can be less stringent than floors for new sources but not 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, the EPA 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

[[Page 66111]]

less frequently than every eight years. CAA section 112(d)(6). In 
conducting this review, the EPA is not required to recalculate the MACT 
floor. Natural Resources Defense Council (NRDC) v. EPA, 529 F.3d 1077, 
1084 (D.C. Cir., 2008). Association of Battery Recyclers, Inc. v. EPA, 
716 F.3d 667 (D.C. Cir. 2013).
    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 the Residual Risk Report to 
Congress, EPA-453/R-99-001 (Risk Report) in March 1999. Congress did 
not act in response, thereby triggering the EPA's obligation under CAA 
section 112(f)(2) to analyze and address residual risk.
    Section 112(f)(2) of the CAA requires the EPA to determine for 
source categories subject to MACT standards whether the emission 
standards provide an ample margin of safety to protect public health. 
Section 112(f)(2)(B) of the CAA expressly preserves the EPA's use of 
the two-step process for developing standards to address any residual 
risk and the agency's 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 EPA notified Congress in the Risk 
Report that the agency intended to use the Benzene NESHAP approach in 
making CAA section 112(f) residual risk determinations (EPA-453/R-99-
001, p. ES-11). The EPA subsequently adopted this approach in its 
residual risk determinations, and in a challenge to the risk review for 
the Synthetic Organic Chemical Manufacturing source category, the 
United States Court of Appeals for the District of Columbia Circuit 
upheld as reasonable the EPA's interpretation that subsection 112(f)(2) 
incorporates the standards established in the Benzene NESHAP. See NRDC 
v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 2008) (``[S]ubsection 
112(f)(2)(B) expressly incorporates the 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, vol. 1, p. 877 (Senate debate on Conference 
Report).
    The first step in this process is the determination of acceptable 
risk. If risks are unacceptable, the EPA cannot consider cost in 
identifying the emissions standards necessary to bring risks to an 
acceptable level. The second step is the determination of whether 
standards must be further revised in order to provide an ample margin 
of safety to protect public health, which is the level at which the 
standards must be set, unless an even more stringent standard is 
necessary to prevent, taking into consideration costs, energy, safety 
and other relevant factors, an adverse environmental effect.
1. Determining Acceptability
    The agency in the Benzene NESHAP concluded that ``that the 
acceptability of risk under section 112 is best judged on the basis of 
a broad set of health risk measures and information'' and that the 
``judgment on acceptability cannot be reduced to any single factor.'' 
Id. at 38046. 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'' (Risk Report at 178, quoting NRDC v. EPA, 824 F.2d 
1146, 1165 (D.C. Cir. 1987) (en banc) (``Vinyl Chloride''), recognizing 
that our world is not risk-free.
    In the Benzene NESHAP, we stated that ``EPA will generally presume 
that if the risk to [the maximum exposed] individual is no higher than 
approximately 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 acknowledged 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 
the MIR as a metric for determining acceptability, we acknowledged in 
the Benzene NESHAP that ``consideration of maximum individual risk * * 
* must take into account the strengths and weaknesses of this measure 
of risk.'' Id. Consequently, the presumptive risk level of 100-in-1 
million (1-in-10 thousand) provides a benchmark for judging the 
acceptability of maximum individual lifetime cancer risk, but does not 
constitute a rigid line for making that determination. Further, in the 
Benzene NESHAP, we noted that:

[p]articular 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 Benzene NESHAP that:

[i]n 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 km exposure radius around facilities, the science 
policy assumptions and estimation uncertainties associated with the 
risk measures, weight of the scientific evidence for human health 
effects, other quantified or unquantified health effects, effects 
due to co-location of facilities, and co-emission of pollutants.

Id. At 38045. 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 noted earlier, in NRDC v. EPA, the court held that section 
112(f)(2) ``incorporates the EPA's interpretation of the Clean Air Act 
from the Benzene Standard.'' The court further held that Congress' 
incorporation of the Benzene standard applies equally to carcinogens 
and non-carcinogens. 529 F.3d at 1081-82. Accordingly, we also consider 
non-cancer risk metrics in our determination of risk acceptability and 
ample margin of safety.
2. Determination of Ample Margin of Safety
    CAA section 112(f)(2) requires the EPA to determine, for source 
categories subject to MACT standards, whether

[[Page 66112]]

those standards provide an ample margin of safety to protect public 
health. As explained in the Benzene NESHAP, ``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 section 112.'' 54 FR 38046.
    According to CAA section 112(f)(2)(A), 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 (i.e. the MACT standards) are 
sufficiently protective. NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 
2008) (``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,\2\ but must consider cost, energy, safety 
and other relevant factors in doing so.
---------------------------------------------------------------------------

    \2\ ``Adverse environmental effect'' is defined 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. CAA section 112(a)(7).
---------------------------------------------------------------------------

    The CAA does not specifically define the terms ``individual most 
exposed,'' ``acceptable level'' and ``ample margin of safety.'' In the 
Benzene NESHAP, 54 FR 38044-38045, we stated as an overall objective:

    In protecting public health with an ample margin of safety under 
section 112, EPA strives 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 
plant would have if he or she were exposed to the maximum pollutant 
concentrations for 70 years.

The agency further stated that ``[t]he 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.'' Id. at 38045.
    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, including the incremental risk reduction 
associated with standards more stringent than the MACT standard or a 
more stringent standard that EPA has determined is necessary to ensure 
risk is acceptable. In the ample margin of safety analysis, the agency 
considers additional factors, 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. What is this source category and how do the MACT standards regulate 
its HAP emissions?

    The MACT standards for Flexible Polyurethane Foam (FPUF) Production 
were promulgated on October 7, 1998, (63 FR 53980) and codified at 40 
CFR part 63, subpart III. The FPUF Production MACT standards apply to 
each new and existing flexible polyurethane foam or rebond foam process 
that produces flexible polyurethane foam or rebond foam, emits HAP, and 
is located at a contiguous, major source plant site. The requirements 
of the standards are the same for both new and existing sources.
    There are three types of FPUF producers in the source category: 
Slabstock, molded and rebond. Slabstock foam is produced in large 
continuous buns that are then cut into the desired size and shape. 
Slabstock foam products are primarily used in furniture seat cushions 
and bedding materials. Molded foam is produced by ``shooting'' the foam 
mixture into a mold of the desired shape and size. Molded foam is 
typically used in automotive seats, packaging and a range of specialty 
products. Rebond foam is made from scrap foam that is converted into a 
material primarily used for carpet underlay. Rebond foam production is 
often co-located with slabstock foam production facilities.
    Slabstock and molded polyurethane foams are produced by mixing 
three major ingredients: A polyol polymer, an isocyanate and water. The 
polyol is either a polyether or polyester polymer with hydroxyl end 
groups. Other ingredients are often added to modify the polymer, and 
catalysts are used to balance the principal foam production reactions. 
Auxiliary blowing agents (ABAs) may be used to produce specific 
densities and grades of foam where the gases produced by the 
isocyanate-water reaction are insufficient to achieve the desired 
density. ABAs are more widely used in the production of slabstock foams 
than in the production of molded foams. Rebond foam is produced from 
scrap slabstock or molded polyurethane foam.
    The HAP emission points at FPUF production facilities depend on the 
type of foam being produced. Prior to compliance with the original FPUF 
Production MACT standards, the primary HAP emission point for slabstock 
foam facilities was the foam production line, due to emissions of HAP 
ABAs. Other HAP emission points at slabstock production facilities 
include storage vessels and equipment leaks. At molded and rebond foam 
facilities, the primary HAP emission points are storage vessels and 
equipment leaks.
    Many facilities discontinued use of HAP ABAs before the rule's 
October 2001 compliance date, allowing these facilities to be 
designated as area sources. Based on the best information available, 
slabstock production facilities using HAP ABAs on, or after, the rule's 
October 2001 compliance date also have discontinued use of HAP-based 
ABAs. We solicit comment on the use of HAP-based ABAs and whether any 
facilities in the FPUF production source category currently use these 
products.
    In the past decade, the FPUF production source category has 
experienced plant closures and consolidations. Today, there are 13 FPUF 
production facilities subject to the MACT standards: 7 slabstock, 6 
molded and 2 rebond. One rebond facility is co-located with a slabstock 
facility, and the other rebond facility is co-located with a molded 
foam facility. A list of these facilities is included in the 
memorandum, Development of the RTR

[[Page 66113]]

Emissions Dataset for the Flexible Polyurethane Foam Production Source 
Category, which is available in the docket for this proposed 
rulemaking.
    The FPUF Production MACT standards contain requirements specific 
for each of the three types of foam production processes. For slabstock 
foam production, the FPUF Production MACT standards include 
diisocyanate and HAP ABA emissions reduction requirements. For molded 
and rebond foam production, the FPUF Production MACT standards prohibit 
the use of HAP in mold release agents and equipment cleaners, except in 
very limited circumstances.
    For slabstock foam production, the FPUF Production MACT standards 
regulate emissions of diisocyanates from storage vessels, transfer 
pumps and equipment leaks. The storage vessel requirements include the 
installation of either a vapor recovery system or a carbon adsorption 
system. Transfer pumps are required to be either sealless pumps or 
pumps submerged in a neutral oil, and submerged pumps must be visually 
inspected periodically for leaks. All components in diisocyanate 
service must be repaired when a leak is detected.
    Standards for HAP ABA emissions at slabstock facilities include 
emission point requirements for the foam production line, storage 
vessels, equipment leaks and equipment cleaning. For the slabstock 
production line, the FPUF Production MACT standards contain 
restrictions on the amount of HAP ABAs that can be used, based on the 
grades of foam produced. The FPUF Production MACT standards also 
regulate HAP ABAs by requiring installation of either a vapor recovery 
system or a carbon adsorption system on storage vessels. For equipment 
leaks, the FPUF Production MACT standards require a leak detection and 
repair program (LDAR) for HAP ABAs. The use of HAP or HAP-based 
products for equipment cleaning is prohibited at slabstock flexible 
polyurethane foam production facilities. This proposed rule also 
includes an alternative source-wide HAP ABA emission limit. The source-
wide emission limit allows slabstock facilities to comply by limiting 
the total amount of a single HAP ABA used, rather than by complying 
with the individual HAP ABA emission point requirements (e.g., 
production line, LDAR, equipment cleaning).
    For molded foam and rebond foam production, the FPUF Production 
MACT standards prohibit the use of HAP-based products as mold release 
agents and as equipment cleaners, except that diisocyanates may be used 
to flush the mixhead and associated piping during startup and 
maintenance if the diisocyanates are contained in a closed-loop system 
and re-used in production.

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

    In 2011, we surveyed nine companies that own and operate foam 
production facilities, as provided for under section 114 of the CAA. We 
also conducted plant visits to four facilities in 2012 and 2013, 
retrieved permit data from approximately 32 state agencies, and 
obtained emissions inventory data from state agencies. Finally, we 
reviewed data in four EPA emission inventory databases: National 
Emissions Inventory (NEI), Emissions Inventory System (EIS), Toxics 
Release Inventory (TRI) and Envirofacts to identify facilities that may 
be part of the source category, emission sources and quantities of 
emissions. The CAA section 114 questionnaire included requests for 
available information regarding process equipment, control devices and 
work practices for emission reductions, point and fugitive emissions 
and other aspects of facility operations.
    The emissions data and risk assessment inputs for the FPUF 
production source category are described further in the memorandum 
Development of the RTR Emissions Dataset for the Flexible Polyurethane 
Foam Production Source Category, which is available in the docket for 
this proposed rulemaking.

III. Analytical Procedures

    In this section, we describe the analyses performed to support the 
proposed decisions for the RTR and other issues addressed in this 
proposal.

A. How did we estimate post-MACT risks posed by the source category?

    The EPA conducted a risk assessment that provided estimates of the 
MIR posed by the HAP emissions from each source in the source category, 
the hazard index (HI) for chronic exposures to HAP with the potential 
to cause non-cancer health effects and the hazard quotient (HQ) for 
acute exposures to HAP with the potential to cause non-cancer health 
effects. The assessment 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 the 
source category. The risk assessment consisted of eight 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 the 
Flexible Polyurethane Foam Production Source Category. The methods used 
to assess risks (as described in the eight 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; \3\ they are also consistent with the key 
recommendations contained in that report.
---------------------------------------------------------------------------

    \3\ U.S. EPA SAB. Risk and Technology Review (RTR) Risk 
Assessment Methodologies: For Review by the EPA's Science Advisory 
Board with Case Studies--MACT I Petroleum Refining Sources and 
Portland Cement Manufacturing, May 2010.
---------------------------------------------------------------------------

1. How did we estimate actual emissions and identify the emissions 
release characteristics?
    Data from the 13 existing FPUF production facilities were used to 
create a dataset that is the basis for the risk assessment. We 
estimated the amount of actual and allowable emissions using data 
collected through the CAA section 114 request, emission inventories 
(EIS, NEI and TRI) and site visits. We performed quality assurance (QA) 
procedures for the emissions data and release characteristics to 
identify any outliers, and then confirmed or corrected the data. For 
facilities where speciated HAP data were unavailable or unreliable, 
more recent inventory data were obtained from state or local permitting 
agencies. In addition to the QA of the source data for the facilities 
contained in the dataset, we also checked the coordinates of every 
emission source in the dataset through visual observations using tools 
such as Google Earth and ArcView, and made corrections, as necessary. 
Further information about the development of the dataset is provided in 
the technical document: Draft Development of the RTR Emissions Dataset 
for the Flexible Polyurethane Foam Production Source Category, which is 
available in the docket for this action.
2. How did we estimate MACT-Allowable emissions?
    The available emissions data in the MACT dataset include estimates 
of the mass of HAP emitted during the specified annual time period. In 
some cases, these ``actual'' emission levels are lower than the 
emission levels a facility is 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

[[Page 66114]]

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 Hazardous 
Organic NESHAP 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 since these risks reflect the maximum level 
facilities could emit and still comply with national emission 
standards. 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.)
    For the FPUF production source category, we determined that actual 
emissions are a reasonable estimate of the MACT-allowable emissions for 
molded and rebond foam facilities. The MACT requirements for these 
facilities are HAP use prohibitions, and both the actual and the MACT-
allowable emissions, while in compliance with these requirements, are 
therefore zero.
    For slabstock foam production facilities, we estimate that the 
level of diisocyanate actual emissions is a reasonable estimate of the 
MACT-allowable diisocyanate emissions. The diisocyanate storage vessels 
and other equipment are subject to equipment standards and work 
practices. For equipment standards, sources subject to the standards 
are required to install specific equipment. In order to comply with 
this proposed rule, the equipment must be maintained properly and in 
good working condition. Therefore, we do not expect any difference 
between the actual emissions level and the level allowed by the MACT 
standards because the level of control typically does not vary for 
equipment standards. Similarly, we do not expect any difference between 
actual and MACT-allowable emissions for emission sources subject to 
work practice requirements, provided that facilities are not conducting 
additional work practices proven to reduce emissions beyond those 
required in this proposed rule. We are not aware of any such situations 
at facilities in this source category. Therefore, for facilities 
complying with the equipment and work practice standards, we believe 
that the actual diisocyanate emission levels are a reasonable 
estimation of the levels allowed by the standards.
    For HAP ABA emissions from slabstock facilities, we estimate that 
MACT-allowable emissions are higher than actual emissions. While we 
believe that all slabstock production facilities have discontinued use 
of HAP-based ABAs, and they are reporting zero emissions of HAP ABA, 
the MACT rule does not prohibit the use of HAP ABAs. Therefore, MACT-
allowable HAP ABA emissions were attributed to each slabstock facility 
based on emissions information gathered during development of the MACT 
standards. We assigned appropriate emissions release parameters for 
each facility, and modeled using the same procedures and tools used for 
modeling actual emissions, to obtain facility-specific maximum risk 
values based on MACT-allowable emissions. The docket for this 
rulemaking contains the following document which provides more 
information on the development of estimated MACT-allowable emissions: 
MACT-Allowable Emissions for the Flexible Polyurethane Foam Production 
Source Category.
3. How did we conduct dispersion modeling, determine inhalation 
exposure and estimate individual and population inhalation risks?
    Both long-term and short-term inhalation exposure concentrations 
and health risks from the source category addressed in this proposal 
were estimated using the Human Exposure Model (Community and Sector 
HEM-3 version 1.1.0). The HEM-3 performs three primary risk assessment 
activities: (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 
kilometers (km) of the modeled sources,\4\ and (3) estimating 
individual and population-level inhalation risks using the exposure 
estimates and quantitative dose-response information.
---------------------------------------------------------------------------

    \4\ This metric comes from the Benzene NESHAP. See 54 FR 38046.
---------------------------------------------------------------------------

    The air dispersion model used by the HEM-3 model (AERMOD) is one of 
the EPA's preferred models for assessing pollutant concentrations from 
industrial facilities.\5\ 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 (2011) of 
hourly surface and upper air observations for more than 824 
meteorological stations, selected to provide coverage of the United 
States and Puerto Rico. A second library of United States Census Bureau 
census block \6\ internal point locations and populations provides the 
basis of human exposure calculations (U.S. Census, 2010). In addition, 
for each census block, the census library includes the elevation and 
controlling hill height, 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.
---------------------------------------------------------------------------

    \5\ 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).
    \6\ A census block is the smallest geographic area for which 
census statistics are tabulated.
---------------------------------------------------------------------------

    In developing the risk assessment for chronic exposures, we used 
the estimated annual average ambient air concentrations of each 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 the 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 
([mu]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). 
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 the EPA guidelines and have undergone a 
peer review process similar to that used by the EPA, we may use such 
dose-

[[Page 66115]]

response values in place of, or, in addition to, other values, if 
appropriate.
    The EPA estimated incremental individual lifetime cancer risks 
associated with emissions from the facilities in the source category 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 carcinogenic potential \7\) emitted 
by the modeled sources. Cancer incidence and the distribution of 
individual cancer risks for the population within 50 km of the sources 
were also estimated for the source category as part of this assessment 
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.
---------------------------------------------------------------------------

    \7\ 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 Science Advisory Board (SAB) in their 
2002 peer review of EPA's National Air Toxics Assessment (NATA) 
titled, 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.
---------------------------------------------------------------------------

    To assess the risk of non-cancer 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 value, which is either the EPA 
reference concentration (RfC) (http://www.epa.gov/riskassessment/glossary.htm), 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: (1) The 
Agency for Toxic Substances and Disease Registry Minimum Risk Level 
(http://www.atsdr.cdc.gov/mrls/index.asp), which is defined as ``an 
estimate of daily human exposure to a hazardous substance that is 
likely to be without an appreciable risk of adverse non-cancer health 
effects (other than cancer) over a specified duration of exposure''; 
(2) the CalEPA Chronic Reference Exposure Level (REL) (http://www.oehha.ca.gov/air/hot_spots/pdf/HRAguidefinal.pdf), which is 
defined as ``the concentration level (that is expressed in units of 
micrograms per cubic meter ([mu]g/m\3\) for inhalation exposure and in 
a dose expressed in units of milligram per kilogram-day (mg/kg-day) for 
oral exposures), 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.
    The EPA also evaluated screening estimates of acute exposures and 
risks 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) emissions rate and worst-case dispersion conditions occur. The 
acute HQ is the estimated acute exposure divided by the acute dose-
response value. In each case, the EPA calculated acute HQ values using 
best available, short-term dose-response 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 emissions 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.'' Id. at page 2. Acute 
REL values are based on the most sensitive, relevant, adverse health 
effect reported in the peer-reviewed medical and toxicological 
literature. Acute REL values are designed to protect the most sensitive 
individuals in the population by the inclusion of margins of safety. 
Because margins of safety are incorporated to address data gaps and 
uncertainties, exceeding the REL 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/oppt/aegl/pubs/sop.pdf),\8\ ``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.'' 
Id. at 2. 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 eight hours.'' Id. at 2. 
The document lays out the purpose and objectives of AEGL by stating 
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.'' Id. at 21. In detailing the intended application 
of AEGL values, the document states 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.'' Id. at 31.
---------------------------------------------------------------------------

    \8\ National Academy of Sciences (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 (expressed as ppm (parts per million) or mg/m\3\ 
(milligrams per cubic meter)) 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.'' Id. at 3. The document also notes that, ``Airborne 
concentrations below AEGL-1 represent exposure levels that can produce 
mild and progressively increasing but transient and

[[Page 66116]]

nondisabling odor, taste, and sensory irritation or certain 
asymptomatic, nonsensory effects.'' Id. Similarly, the document defines 
AEGL-2 values as ``the airborne concentration (expressed as parts per 
million or milligrams per cubic meter) 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.'' Id.
    ERPG values are derived for use in emergency response, as described 
in the American Industrial Hygiene Association's ERP Committee document 
titled, ERPGS Procedures and Responsibilities (http://sp4m.aiha.org/insideaiha/GuidelineDevelopment/ERPG/Documents/ERP-SOPs2006.pdf), which 
states that, ``Emergency Response Planning Guidelines were developed 
for emergency planning and are intended as health based guideline 
concentrations for single exposures to chemicals.'' \9\ Id. at 1. 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.'' Id. at 2. 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 one hour without 
experiencing or developing irreversible or other serious health effects 
or symptoms which could impair an individual's ability to take 
protective action.'' Id. at 1.
---------------------------------------------------------------------------

    \9\ ERP Committee Procedures and Responsibilities. November 1, 
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, we compare 
higher severity level AEGL-2 or ERPG-2 values 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 the same as 
the corresponding ERPG-1 values, and AEGL-2 values are often equal to 
ERPG-2 values. Maximum HQ values from our acute screening risk 
assessments typically result when basing them on the acute REL 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 
emissions rates by a default factor to cover routinely variable 
emissions. We choose the factor to use partially based on process 
knowledge and engineering judgment, but also reflecting a Texas study 
of short-term emissions variability, which showed that most peak 
emission events in a heavily-industrialized four-county area (Harris, 
Galveston, Chambers and Brazoria Counties, Texas) were less than twice 
the annual average hourly emissions rate. The highest peak emissions 
event was 74 times the annual average hourly emissions rate, and the 
99th percentile ratio of peak hourly emissions rate to the annual 
average hourly emissions rate was 9.\10\ 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 this source 
category, however, there was no such information available and the 
default factor of 10 was used in the acute screening process.
---------------------------------------------------------------------------

    \10\ See http://www.tceq.state.tx.us/compliance/field_ops/eer/index.html or docket to access the source of these data.
---------------------------------------------------------------------------

    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 (even 
under the conservative assumptions of the screening analysis), acute 
impacts were deemed negligible and no further analysis was performed. 
In 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. 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 emissions 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,\11\ we generally examine a wider range of 
available acute health metrics (e.g., RELs, AEGLs) 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 \12\ for 
HAP have been developed, we consider additional acute values (i.e., 
occupational and international values) to provide a more complete risk 
characterization.
---------------------------------------------------------------------------

    \11\ 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.
    \12\ 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.
---------------------------------------------------------------------------

4. How did we conduct the multipathway exposure and risk screening?
    The EPA conducted a screening analysis examining the potential for 
significant human health risks due to exposures via routes other than 
inhalation (i.e., ingestion). We first determined whether any sources 
in the source category emitted any hazardous air pollutants known to be 
persistent and bioaccumulative in the environment (PB-HAP). The PB-HAP 
compounds or compound classes are identified for the screening from the 
EPA's Air Toxics Risk Assessment Library (available at http://www.epa.gov/ttn/fera/risk_atra_vol1.html).
    For the FPUF production source category, we did not identify 
emissions of any PB-HAP. Because we did not identify PB-HAP emissions, 
no further

[[Page 66117]]

evaluation of multipathway risk was conducted for this source category.
5. How did we assess risks considering emissions control options?
    In addition to assessing baseline inhalation risks and screening 
for potential multipathway risks, we also estimated risks considering 
the potential emissions reductions that would be achieved by the 
control options under consideration. In these cases, the expected 
emissions reductions were applied to the specific HAP and emissions 
points in the source category dataset to develop corresponding 
estimates of risk and incremental risk reductions.
6. How did we conduct the environmental risk screening assessment?
a. Adverse Environmental Effect
    The EPA developed a screening approach to examine the potential for 
adverse environmental effects as required under section 112(f)(2)(A) of 
the CAA. Section 112(a)(7) of the CAA defines ``adverse environmental 
effect'' as ``any significant and widespread adverse effect, which may 
reasonably be anticipated, to wildlife, aquatic life, or other natural 
resources, including adverse impacts on populations of endangered or 
threatened species or significant degradation of environmental quality 
over broad areas.''
b. Environmental HAP
    The EPA focuses on seven HAP, which we refer to as ``environmental 
HAP,'' in its screening analysis: Five persistent bioaccumulative HAP 
(PB-HAP) and two acid gases. The five PB-HAP are cadmium, dioxins/
furans, polycyclic organic matter (POM), mercury (both inorganic 
mercury and methyl mercury) and lead. The two acid gases are hydrogen 
chloride (HCl) and hydrogen fluoride (HF). The rationale for including 
these seven HAP in the environmental risk screening analysis is 
presented below.
    HAP that persist and bioaccumulate are of particular environmental 
concern because they accumulate in the soil, sediment and water. The 
PB-HAP are taken up, through sediment, soil, water, and/or ingestion of 
other organisms, by plants or animals (e.g., small fish) at the bottom 
of the food chain. As larger and larger predators consume these 
organisms, concentrations of the PB-HAP in the animal tissues increases 
as does the potential for adverse effects. The five PB-HAP we evaluate 
as part of our screening analysis account for 99.8 percent of all PB-
HAP emissions (based on data from the 2005 NEI).
    In addition to accounting for almost all of the mass of PB-HAP 
emitted, we note that the TRIM.Fate model that we use to evaluate 
multipathway risk allows us to estimate concentrations of cadmium 
compounds, dioxins/furans, POM and mercury in soil, sediment and water. 
For lead, we currently do not have the ability to calculate these 
concentrations using the TRIM.Fate model. Therefore, to evaluate the 
potential for environmental effects from lead, we compare the estimated 
chronic inhalation exposures from the source category emissions of lead 
with the level of the secondary National Ambient Air Quality Standard 
(NAAQS) for lead.\13\ We consider values below the level of the 
secondary lead NAAQS as unlikely to cause adverse environmental 
effects.
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    \13\ The secondary lead NAAQS is a reasonable measure of 
determining whether there is an adverse environmental effect since 
it was established considering ``effects on soils, water, crops, 
vegetation, man-made materials, animals, wildlife, weather, 
visibility and climate, damage to and deterioration of property, and 
hazards to transportation, as well as effects on economic values and 
on personal comfort and well-being.''
---------------------------------------------------------------------------

    Due to their well-documented potential to cause direct damage to 
terrestrial plants, we include two acid gases, HCl and HF, in the 
environmental screening analysis. According to the 2005 NEI, HCl and HF 
account for about 99 percent of the total acid gas HAP emitted by 
stationary sources. In addition to the potential to cause direct damage 
to plants, high concentrations of HF in the air have been linked to 
fluorosis in livestock. Air concentrations of these HAP are already 
calculated as part of the human multipathway exposure and risk 
screening analysis using the HEM3-AERMOD air dispersion model, and we 
are able to use the air dispersion modeling to estimate the potential 
for an adverse environmental effect.
    For the FPUF production source category, the data do not show 
emissions of any of the seven HAP (cadmium, dioxins/furans, POM, 
mercury, HCL or HF) in the environmental risk screen. Because we did 
not identify emissions of these seven HAP from the source category, we 
did not conduct any further quantitative evaluation of environmental 
risk.
    The EPA acknowledges that other HAP beyond the seven HAP discussed 
above may have the potential to cause adverse environmental effects. 
Therefore, the EPA may include other relevant HAP in its environmental 
risk screening in the future, as modeling science and resources allow. 
The EPA invites comment on the extent to which other HAP emitted by the 
source category may cause adverse environmental effects. Such 
information should include references to peer-reviewed ecological 
effects benchmarks that are of sufficient quality for making regulatory 
decisions, as well as information on the presence of organisms located 
near facilities within the source category that such benchmarks 
indicate could be adversely affected.
7. How did we conduct facility-wide assessments?
    To put the source category risks in context, we typically examine 
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, we examine the HAP emissions not only from the 
source category emission points of interest, but also emissions of HAP 
from all other emissions sources at the facility for which we have 
data. The emissions data for estimating these ``facility-wide'' risks 
were obtained from the 2005 NEI (available at http://www.epa.gov/ttn/atw/nata2005). 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 FPUF production source category risks were compared to the 
facility-wide risks to determine the portion of facility-wide risks 
that could be attributed to the FPUF production source category. We 
specifically examined the facilities associated with the highest 
estimates of risk and determined the percentage of that risk 
attributable to the FPUF production source category. The Draft Residual 
Risk Assessment for the Flexible Polyurethane Foam Production Source 
Category, available through the docket for this action, provides all 
the methodology and results of the facility-wide analyses, including 
all facility-wide risks and the percentage of FPUF production source 
category contribution to facility-wide risks.
8. How did we consider uncertainties in risk assessment?
    In the Benzene NESHAP, we concluded that risk estimation 
uncertainty should be considered in our decision-making under the ample 
margin of safety framework. Uncertainty and the potential for bias are 
inherent in all risk assessments, including those performed for this 
proposal. Although uncertainty exists, we believe that our

[[Page 66118]]

approach, which used conservative tools and assumptions, ensures that 
our decisions are health-protective. A brief discussion of the 
uncertainties in the emissions dataset, dispersion modeling, inhalation 
exposure estimates and dose-response relationships follows below. A 
more thorough discussion of these uncertainties is included in the 
Draft Residual Risk Assessment for the Flexible Polyurethane Foam 
Production Source Category, which is available in the docket for this 
action.
a. Uncertainties in the Emissions Dataset
    Although the development of the RTR dataset 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 datasets are accurate, errors in emissions estimates and 
other factors. The emission estimates considered in this analysis 
generally are annual totals for certain years, and they do not reflect 
short-term fluctuations during the course of a year or variations from 
year to year. The estimates of peak hourly emissions rates for the 
acute effects screening assessment were based on an emission adjustment 
factor applied to the average annual hourly emissions rates, which are 
intended to account for emission fluctuations due to normal facility 
operations.
b. Uncertainties in Dispersion Modeling
    We recognize there is uncertainty in ambient concentration 
estimates associated with any model, including the EPA's recommended 
regulatory dispersion model, AERMOD. In using a model to estimated 
ambient pollutant concentrations, the user chooses certain options to 
apply. For RTR assessments, we select some model options that have the 
potential to overestimate ambient air concentrations (e.g., not 
including plume depletion or pollutant transformation). We select other 
model options that have the potential to underestimate ambient impacts 
(e.g., not including building downwash). Other options that we select 
have the potential to either under- or over-estimate ambient levels 
(e.g., meteorology and receptor locations). On balance, considering the 
directional nature of the uncertainties commonly present in ambient 
concentrations estimated by dispersion models, the approach we apply in 
the RTR assessments should yield unbiased estimates of ambient HAP 
concentrations.
c. Uncertainties in Inhalation Exposure
    The EPA did not include the effects of human mobility on exposures 
in the assessment. Specifically, short-term mobility and long-term 
mobility between census blocks in the modeling domain were not 
considered.\14\ The approach of not considering short- or long-term 
population mobility does not bias the estimate of the theoretical MIR 
(by definition), 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 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-10 thousand or 1-in-1 million).
---------------------------------------------------------------------------

    \14\ Short-term mobility is movement from one micro-environment 
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 is an unbiased estimate 
of average risk and incidence. We reduce this uncertainty by analyzing 
large census blocks near facilities using aerial imagery and adjusting 
the location of the block centroid to better represent the population 
in the block, as well as adding additional receptors where the block 
population is not well represented by a single location.
    The assessment evaluates the cancer inhalation risks associated 
with 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 
domestic facilities) will influence the future risks posed by a given 
source or 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 the unlikely scenario where a facility 
maintains, or even increases, its emissions levels over a period of 
more than 70 years, residents live beyond 70 years at the same 
location, and the residents spend most of their days at that location, 
then the cancer inhalation risks could potentially be underestimated. 
However, annual cancer incidence estimates from exposures to emissions 
from these sources would not be affected by the length of time an 
emissions source operates.
    The exposure estimates used in these analyses assume chronic 
exposures to ambient (outdoor) 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 of the HAP, indoor levels are roughly equivalent to 
ambient levels, but for very reactive pollutants or larger particles, 
indoor levels are typically lower. This factor has the potential to 
result in an overstatement of 25 to 30 percent of exposures.\15\
---------------------------------------------------------------------------

    \15\ 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 factors specific to the acute exposure assessment that should 
be highlighted. The accuracy of an acute inhalation exposure assessment 
depends on the simultaneous occurrence of independent factors that may 
vary greatly, such as hourly emissions rates, meteorology and human 
activity patterns. In this assessment, we assume that individuals 
remain for 1 hour at the point of maximum ambient concentration as 
determined by the co-occurrence of peak emissions and worst-case 
meteorological conditions. These assumptions would tend to 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 dose-
response values used in our risk assessments for cancer effects from 
chronic exposures and non-cancer effects from both chronic and acute 
exposures. Some uncertainties may be considered quantitatively, and 
others generally are

[[Page 66119]]

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 variability in dose-
response relationships is given in the Draft Residual Risk Assessment 
for the Flexible Polyurethane Foam Production Source Category, 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).\16\ In some circumstances, the true risk could be as 
low as zero; however, in other circumstances the risk could be 
greater.\17\ 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).
---------------------------------------------------------------------------

    \16\ IRIS glossary (http://www.epa.gov/NCEA/iris/help_gloss.htm).
    \17\ 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.
---------------------------------------------------------------------------

    RfCs and reference doses (RfDs) represent chronic exposure levels 
that provide an estimate (with uncertainty spanning perhaps an order of 
magnitude) of a continuous inhalation exposure or a daily oral 
exposure, respectively, 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 
considers uncertainty, variability and gaps in the available data. The 
UFs are applied to derive reference values that are intended to protect 
against appreciable risk of deleterious effects. The UFs are commonly 
default values,\18\ e.g., factors of 10 or 3, used in the absence of 
compound-specific data; where data are available, UFs may also be 
developed using compound-specific information. When data are limited, 
more assumptions are needed and more UFs are used.
---------------------------------------------------------------------------

    \18\ According to the NRC report, Science and Judgment in Risk 
Assessment (NRC, 1994) ``[Default] options are generic approaches, 
based on general scientific knowledge and policy judgment, that are 
applied to various elements of the risk assessment process when the 
correct scientific model is unknown or uncertain.'' The 1983 NRC 
report, Risk Assessment in the Federal Government: Managing the 
Process, defined default option as ``the option chosen on the basis 
of risk assessment policy that appears to be the best choice in the 
absence of data to the contrary'' (NRC, 1983a, p. 63). Therefore, 
default options are not rules that bind the agency; rather, the 
agency may depart from them in evaluating the risks posed by a 
specific substance when it believes this to be appropriate. In 
keeping with EPA's goal of protecting public health and the 
environment, default assumptions are used to ensure that risk to 
chemicals is not underestimated (although defaults are not intended 
to overtly overestimate risk). See EPA, 2004, An Examination of EPA 
Risk Assessment Principles and Practices, EPA/100/B-04/001 available 
at: http://www.epa.gov/osa/pdfs/ratf-final.pdf.
---------------------------------------------------------------------------

    While collectively termed ``UF,'' these factors account for a 
number of different quantitative considerations when 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. The 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.
    For a group of compounds that are unspeciated (e.g., glycol 
ethers), we conservatively use the most protective reference value of 
an individual compound in that group to estimate risk. Similarly, for 
an individual compound in a group (e.g., ethylene glycol diethyl ether) 
that does not have a specified reference value, we also apply the most 
protective reference value from the other compounds in the group to 
estimate risk.
e. Uncertainties in the Multipathway Assessment
    For each source category, we generally rely on site-specific levels 
of PB-HAP emissions to determine whether a refined assessment of the 
impacts from multipathway exposures is necessary. This determination is 
based on the results of a two-tiered screening analysis that relies on 
the outputs from models that estimate environmental pollutant 
concentrations and human exposures for four PB-HAP. Two important types 
of uncertainty associated with the use of these models in RTR risk 
assessments and inherent to any assessment that relies on environmental 
modeling are model uncertainty and input uncertainty.\19\
---------------------------------------------------------------------------

    \19\ In the context of this discussion, the term ``uncertainty'' 
as it pertains to exposure and risk encompasses both variability in 
the range of expected inputs and screening results due to existing 
spatial, temporal, and other factors, as well as uncertainty in 
being able to accurately estimate the true result.

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

[[Page 66120]]

    Model uncertainty concerns whether the selected models are 
appropriate for the assessment being conducted and whether they 
adequately represent the actual processes that might occur for that 
situation. An example of model uncertainty is the question of whether 
the model adequately describes the movement of a pollutant through the 
soil. This type of uncertainty is difficult to quantify. However, based 
on feedback received from previous EPA Science Advisory Board reviews 
and other reviews, we are confident that the models used in the screen 
are appropriate and state-of-the-art for the multipathway risk 
assessments conducted in support of RTR.
    Input uncertainty is concerned with how accurately the models have 
been configured and parameterized for the assessment at hand. For Tier 
1 of the multipathway screen, we configured the models to avoid 
underestimating exposure and risk to reduce the likelihood that the 
results indicate the risks are lower than they actually are. This was 
accomplished by selecting upper-end values from nationally-
representative data sets for the more influential parameters in the 
environmental model, including selection and spatial configuration of 
the area of interest, lake location and size, meteorology, surface 
water and soil characteristics and structure of the aquatic food web. 
We also assume an ingestion exposure scenario and values for human 
exposure factors that represent reasonable maximum exposures.
    In Tier 2 of the multipathway assessment, we refine the model 
inputs to account for meteorological patterns in the vicinity of the 
facility versus using upper-end national values and we identify the 
actual location of lakes near the facility rather than the default lake 
location that we apply in Tier 1. By refining the screening approach in 
Tier 2 to account for local geographical and meteorological data, we 
decrease the likelihood that concentrations in environmental media are 
overestimated, thereby increasing the usefulness of the screen. The 
assumptions and the associated uncertainties regarding the selected 
ingestion exposure scenario are the same for Tier 1 and Tier 2.
    For both Tiers 1 and 2 of the multipathway assessment, our approach 
to addressing model input uncertainty is generally cautious. We choose 
model inputs from the upper end of the range of possible values for the 
influential parameters used in the models, and we assume that the 
exposed individual exhibits ingestion behavior that would lead to a 
high total exposure. This approach reduces the likelihood of not 
identifying high risks for adverse impacts.
    Despite the uncertainties, when individual pollutants or facilities 
do screen out, we are confident that the potential for adverse 
multipathway impacts on human health is very low. On the other hand, 
when individual pollutants or facilities do not screen out, it does not 
mean that multipathway impacts are significant, only that we cannot 
rule out that possibility and that a refined multipathway analysis for 
the site might be necessary to obtain a more accurate risk 
characterization for the source category.
    For further information on uncertainties and the Tier 1 and 2 
screening methods, refer to the risk document Appendix 5, ``Technical 
Support Document for TRIM-Based Multipathway Tiered Screening 
Methodology for RTR.''

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

    As discussed in section II.A of this preamble, in evaluating and 
developing standards under section 112(f)(2), we apply a two-step 
process 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 limit on maximum individual lifetime [cancer] risk (MIR) 
\20\ of approximately [1-in-10 thousand] [i.e., 100-in-1 million].'' 54 
FR 38045. If risks are unacceptable, the EPA must determine the 
emissions standards necessary to bring risks to an acceptable level 
without considering costs. In the second step of the process, the EPA 
considers whether the emissions standards provide an ample margin of 
safety ``in consideration of all health information, including the 
number of persons at risk levels higher than approximately 1-in-1 
million, as well as other relevant factors, including costs and 
economic impacts, technological feasibility, and other factors relevant 
to each particular decision.'' Id. The EPA must promulgate tighter 
emission standards if necessary to provide an ample margin of safety. 
After conducting the ample margin of safety analysis, we consider 
whether a more stringent standard is necessary to prevent, taking into 
consideration costs, energy, safety, and other relevant factors, an 
adverse environmental effect. After conducting the ample margin of 
safety analysis, we consider whether a more stringent standard is 
necessary to prevent, taking into consideration costs, energy, safety, 
and other relevant factors, an adverse environmental effect.
---------------------------------------------------------------------------

    \20\ 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 considered a number of human 
health risk metrics associated with emissions from the categories under 
review, including the MIR, the number of persons in various risk 
ranges, cancer incidence, the maximum non-cancer HI and the maximum 
acute non-cancer hazard. See, e.g., 72 FR 25138, May 3, 2007; 71 FR 
42724, July 27, 2006. The EPA considered this health information for 
both actual and allowable emissions. See, e.g., 75 FR 65068, October 
21, 2010; 75 FR 80220, December 21, 2010; 76 FR 29032, May 19, 2011. 
The EPA also discussed risk estimation uncertainties and considered the 
uncertainties in the determination of acceptable risk and ample margin 
of safety in these past actions. The EPA considered this same type of 
information in support of this Federal Register notice.
    The agency is considering these various measures of health 
information to inform our determinations of risk acceptability and 
ample margin of safety under CAA section 112(f). 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. Similarly, with regard to the ample margin 
of safety determination, ``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 Benzene NESHAP provides flexibility regarding factors the EPA 
may consider in making determinations and how the EPA may weigh those 
factors for each source category. In responding to comment on our 
policy under the Benzene NESHAP, the EPA explained that:

[t]he 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 non-cancer 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.

[[Page 66121]]

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 
explained that ``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 EPA 
stated in the Benzene NESHAP 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. We also consider the uncertainties associated 
with the various risk analyses, as discussed earlier in this preamble, 
in our determinations of acceptability and ample margin of safety.
    The EPA notes that it has not considered certain health information 
to date in making residual risk determinations. At this time, we do not 
attempt to quantify those HAP risks that may be associated with 
emissions from other facilities that do not include the source 
categories in question, mobile source emissions, natural source 
emissions, persistent environmental pollution or atmospheric 
transformation in the vicinity of the sources in these categories.
    The agency understands the potential importance of considering an 
individual's total exposure to HAP in addition to considering exposure 
to HAP emissions from the source category and facility. We recognize 
that such consideration may be particularly important when assessing 
non-cancer risks, where pollutant-specific exposure health reference 
levels (e.g., RfCs) are based on the assumption that thresholds exist 
for adverse health effects. For example, the agency recognizes that, 
although exposures attributable to emissions from a source category or 
facility alone may not indicate the potential for increased risk of 
adverse non-cancer health effects in a population, the exposures 
resulting from emissions from the facility in combination with 
emissions from all of the other sources (e.g., other facilities) to 
which an individual is exposed may be sufficient to result in increased 
risk of adverse non-cancer health effects. In May 2010, the SAB advised 
the EPA ``that RTR assessments will be most useful to decision makers 
and communities if results are presented in the broader context of 
aggregate and cumulative risks, including background concentrations and 
contributions from other sources in the area.'' \21\
---------------------------------------------------------------------------

    \21\ EPA's responses to this and all other key recommendations 
of the SAB's advisory on RTR risk assessment methodologies (which is 
available at: http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf) 
are outlined in a memo to this rulemaking docket from David Guinnup 
titled, EPA's Actions in Response to the Key Recommendations of the 
SAB Review of RTR Risk Assessment Methodologies.
---------------------------------------------------------------------------

    In response to the SAB recommendations, the EPA is incorporating 
cumulative risk analyses into its RTR risk assessments. The agency is: 
(1) Conducting facility-wide assessments, which include source category 
emission points as well as other emission points within the facilities; 
(2) considering overlapping sources in the same category; and (3) for 
some persistent and bioaccumulative pollutants, analyzing the ingestion 
route of exposure. In addition, the RTR risk assessments have always 
considered aggregate cancer risk from all carcinogens and aggregate 
non-cancer hazard indices from all non-carcinogens affecting the same 
target organ system.
    Although we are interested in placing source category and facility-
wide HAP risks in the context of total HAP risks from all sources 
combined in the vicinity of each source, we are concerned about the 
uncertainties of doing so. Because of the contribution to total HAP 
risk from emissions sources other than those that we have studied in 
depth during this RTR review, such estimates of total HAP risks would 
have significantly greater associated uncertainties than the source 
category or facility-wide estimates. Such aggregate or cumulative 
assessments would compound those uncertainties, making the assessments 
too unreliable.

C. How did we perform the technology review?

    Our technology review focused on the identification and evaluation 
of developments in practices, processes and control technologies that 
have occurred since the FPUF Production MACT standards were 
promulgated. Where we identified such developments, in order to inform 
our decision of whether it is ``necessary'' to revise the emissions 
standards, we analyzed the technical feasibility of applying these 
developments, and the estimated costs, energy implications, non-air 
environmental impacts, as well as considering the emissions reductions. 
We also considered the appropriateness of applying controls to new 
sources versus retrofitting existing sources.
    Based on our analyses of the available data and information, we 
identified potential developments in practices, processes and control 
technologies. For 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 development of the original MACT 
standards.
     Any improvements in add-on control technology or other 
equipment (that were identified and considered during development of 
the original MACT standards) that could result in additional emissions 
reduction.
     Any work practice or operational procedure that was not 
identified or considered during development of the original MACT 
standards.
     Any process change or pollution prevention alternative 
that could be broadly applied to the industry and that was not 
identified or considered during development of the original MACT 
standards.
     Any significant changes in the cost (including cost 
effectiveness) of applying controls (including controls the EPA 
considered during the development of the original MACT standards).
    We reviewed a variety of data sources in our investigation of 
potential practices, processes or controls to consider. Among the 
sources we reviewed were the NESHAP for various industries that were 
promulgated since the FPUF Production MACT standards being reviewed in 
this action. We reviewed the regulatory requirements and/or technical 
analyses associated with these regulatory actions to identify any 
practices, processes and control technologies considered in these 
efforts that could be applied to emissions

[[Page 66122]]

sources in the FPUF production source category, as well as the costs, 
non-air impacts and energy implications associated with the use of 
these technologies. Additionally, we requested information from 
facilities regarding developments in practices, processes or control 
technology. Finally, we reviewed information from other sources, such 
as state and/or local permitting agency databases and industry-
supported databases.

D. What other analyses and reviews were conducted in support of this 
proposal and how did we conduct those analyses and reviews?

    In addition to the analyses described above, we reviewed the FPUF 
Production MACT standards to determine whether we should make 
additional amendments. From this review we have identified one 
additional revision. We are proposing revisions to the startup, 
shutdown and malfunction (SSM) provisions of the MACT rule in order to 
ensure that they are consistent with the court decision in Sierra Club 
v. EPA, 551 F.3d 1019 (D.C. Cir. 2008), which vacated two provisions 
that exempted sources from the requirement to comply with otherwise 
applicable section 112(d) emission standards during periods of SSM. Our 
analyses and proposed changes related to these issues are presented in 
section IV.D of this preamble.

IV. Analytical Results and Proposed Decisions

    This section of the preamble provides the results of our RTR 
reviews of the FPUF Production MACT standards and our proposed 
revisions to the FPUF Production MACT standards regarding the startup, 
shutdown and malfunction provisions.

A. What are the results of the risk assessment and analyses?

    As described above, for the FPUF production source category, we 
conducted an inhalation risk assessment for all HAP emitted, a 
multipathway screening analysis for PB-HAP emitted and an environmental 
HAP screening analysis. We also performed a facility-wide risk 
assessment for the facilities in the source category. Results of the 
risk assessment are presented briefly below and in more detail in the 
residual risk document: Draft Residual Risk Assessment for the Flexible 
Polyurethane Foam Production Source Category, which is available in the 
docket for this rulemaking.
1. FPUF Production Source Category Inhalation Risk Assessment Results
    Table 2 of this preamble provides a summary of the results of the 
inhalation risk assessment for the source category.

                                                        Table 2--Flexible Polyurethane Foam Production Inhalation Risk Assessment Results
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Maximum individual     Estimated population      Estimated annual      Maximum chronic non-          Maximum screening acute non-cancer HQ \4\
                                            cancer risk  (in 1     at increased risk of      cancer incidence        cancer TOSHI \3\    -------------------------------------------------------
                                               million) \2\          cancer >= 1-in-1        (cases per year)    ------------------------
                                         ------------------------         million        ------------------------
        Number of facilities \1\                                 ------------------------                          Based on    Based on
                                           Based on    Based on    Based on    Based on    Based on    Based on     actual     allowable   Based on actual emissions      Based on allowable
                                            actual     allowable    actual     allowable    actual     allowable   emissions   emissions             level                  emissions level
                                           emissions   emissions   emissions   emissions   emissions   emissions     level       level
                                           level \2\     level     level \2\     level     level \2\     level
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
13......................................         0.7           5           0         700     0.00004      0.0004         0.9         0.9  HQERPG	1 = 0.9              HQREL = 4
                                                                                                                                                                      HQERPG	1=0.9
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk due to HAP emissions from the source category.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the FPUF production 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.A.3 of this
  preamble for explanation of acute dose-response values.

    The results of the inhalation risk modeling using actual emissions 
level data, as shown in Table 2, indicate that the maximum lifetime 
individual cancer risk could be up to 0.7-in-1 million, the maximum 
chronic non-cancer TOSHI value could be up to 0.9, and the maximum off-
site acute HQ value could be up to 0.9. The total estimated national 
cancer incidence from these facilities based on actual emission levels 
is 0.00004 excess cancer cases per year or one case in every 25,000 
years.
    As discussed in section III.A.2, we also determined that MACT-
allowable HAP ABA emissions levels at slabstock production facilities 
are greater than actual HAP ABA emissions, while allowable emissions 
from all other processes are equal to actual emissions. The inhalation 
risk modeling using MACT-allowable HAP ABA emissions and the actual 
emissions for the other processes at slabstock production facilities, 
indicate that the maximum lifetime individual cancer risk could be up 
to 5-in-1 million, the maximum chronic non-cancer TOSHI value could be 
up to 0.9, and the maximum off-site acute HQ value could be up to 4, 
based on the REL value for methylene chloride. The total estimated 
national cancer incidence from these facilities based on the MACT-
allowable emission levels is 0.0004 excess cancer cases per year or one 
case in every 2,500 years. For more detail about the MACT-allowable 
emissions levels, see the memorandum, MACT-Allowable Emissions for the 
Flexible Polyurethane Foam Production Source Category, in the docket 
for this rulemaking.
2. Acute Risk Results
    Table 2 shows the acute risk results for the FPUF production source 
category. The screening analysis for worst-case acute impacts was based 
on a conservative default emissions multiplier of 10 to estimate the 
peak hourly emission rates from the average rates. Refer to Appendix 6 
of the draft residual risk document in the docket for the detailed 
acute risk results.
3. Multipathway Risk Screening Results
    There are no PB-HAP emitted by facilities in this category. 
Therefore, we do not expect there is a potential for human health 
multipathway risks as a result of emissions of these HAP.
4. Ecological Risk Screening Results
    The emissions data for the FPUF source category indicate that 
sources within this source category do not emit any of the seven 
pollutants that we identified as ``environmental HAP,'' as discussed 
earlier in this preamble. Based on the processes and materials used in 
the source category, we do not expect any of the seven environmental 
HAP to be emitted. Also, we are unaware of any adverse environmental 
effect caused by emissions of HAP that are emitted by this source 
category. Therefore, we do not expect an adverse environmental effect 
as a result of HAP emissions from this source category.

[[Page 66123]]

5. Facility-Wide Inhalation Risk Assessment Results
    Table 3 displays the results of the facility-wide risk assessment. 
This assessment is based on actual emission levels. For detailed 
facility-specific results, see Appendix 6 of the Draft Residual Risk 
Assessment for the Flexible Polyurethane Foam Production Source 
Category in the docket for this rulemaking.

     Table 3--FPUF Production Facility-Wide Risk Assessment Results
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Number of facilities analyzed..................................     13
Cancer Risk:
    Estimated maximum facility-wide individual cancer risk (in      20
     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 FPUF production source         0
     category contributes 50 percent or more to the facility-
     wide individual cancer risks of 100-in-1 million or more..
    Number of facilities with estimated facility-wide                3
     individual cancer risk of 1-in-1 million or more..........
    Number of facilities at which the FPUF production source         0
     category contributes 50 percent or more to the facility-
     wide individual cancer risk of 1-in-1 million or more.....
Chronic Non-cancer Risk:
    Maximum facility-wide chronic non-cancer TOSHI.............      0.9
    Number of facilities with facility-wide maximum non-cancer       0
     TOSHI greater than 1......................................
    Number of facilities at which the FPUF production source         0
     category contributes 50 percent or more to the facility-
     wide maximum non-cancer TOSHI of 1 or more................
------------------------------------------------------------------------

    The facility-wide MIR and TOSHI are based on actual emissions from 
all emissions sources at the identified facilities. The results 
indicate that 3 facilities have a facility-wide cancer MIR greater than 
or equal to 1-in-1 million. The maximum facility-wide MIR is 20-in-1 
million, with emission points from the FPUF production source category 
contributing less than 10 percent of the maximum facility-wide risk. 
The maximum facility-wide TOSHI is 0.9, with the FPUF production source 
category contributing 100 percent to the facility-wide TOSHI.
6. What demographic groups might benefit from this regulation?
    To determine whether or not to conduct a demographics analysis, we 
look at a combination of factors including the MIR, non-cancer TOSHI, 
population around the facilities in the source category and other 
relevant factors. For the FPUF production source category, our analyses 
show that actual emissions result in no individuals being exposed to 
cancer risk greater than 1-in-1 million or a non-cancer TOSHI greater 
than 1. Therefore, we did not conduct an assessment of risks to 
individual demographic groups for this rulemaking. However, we did 
conduct a proximity analysis, which identifies any overrepresentation 
of minority, low income or indigenous populations near facilities in 
the source category. The results of this analysis are presented in the 
section of this preamble titled, ``Executive Order 12898: Federal 
Actions to Address Environmental Justice in Minority Populations and 
Low-Income Populations.''

B. What are our proposed decisions regarding risk acceptability, ample 
margin of safety and adverse environmental effects?

1. Risk Acceptability
    As noted in section III.C of this preamble, we weigh all health 
risk factors in our risk acceptability determination, including the 
cancer MIR; the number of persons in various cancer and non-cancer risk 
ranges; cancer incidence; the maximum non-cancer TOSHI; the maximum 
acute non-cancer HQ; the extent of non-cancer risks; the potential for 
adverse environmental effects; the distribution of cancer and non-
cancer risks in the exposed population; and risk estimation 
uncertainties (54 FR 38044, September 14, 1989).
    For the FPUF production source category, the risk analysis 
indicates that the cancer risks to the individual most exposed could be 
up to 0.7-in-1 million due to actual emissions and 5-in-1 million based 
on MACT-allowable emissions. These risks are considerably less than 
100-in-1 million, which is the presumptive upper limit of acceptable 
risk. The risk analysis also shows very low cancer incidence (0.00004 
cases per year), as well as no potential for adverse chronic or multi-
pathway health effects. In addition, the risk assessment indicates no 
significant potential for multi-pathway health effects or adverse 
environmental effects. The acute non-cancer risks based on actual 
emissions are all below an HQ of 1. Therefore, we find there is little 
potential concern of acute non-cancer health impacts from actual 
emissions. For acute non-cancer risks based on allowable emissions, 
there was an HQ of 4 based on the REL for methylene chloride. Since the 
acute modeling scenario is worst-case because of its confluence of peak 
emission rates and worst-case dispersion conditions, and since the HQ 
estimates for methylene chloride based on the AEGL-1 and ERPG-1 values 
for this facility are below 1, we are proposing to find that acute non-
cancer health impacts of concern are unlikely.
    Considering all of the health risk information and factors 
discussed above, including the uncertainties discussed in section 
III.A.8 of this preamble, we propose that the risks from the FPUF 
production source category are acceptable.
2. Ample Margin of Safety Analysis and Proposed Controls
    Although we are proposing that the risks from the FPUF production 
source category are acceptable, risk estimates for 700 individuals in 
the exposed population are above 1-in-1 million at the MACT-allowable 
emissions levels. Consequently, we further considered whether the FPUF 
Production MACT standards provide an ample margin of safety to protect 
public health at the MACT-allowable emissions levels. In this ample 
margin of safety analysis, we investigated available emissions control 
options that might reduce the risk associated with MACT-allowable 
emissions from the source category. We considered this information 
along with all of the health risks and other health information 
considered in our determination of risk acceptability.
    For HAP used as an ABA at slabstock foam production facilities, we 
considered prohibiting facilities from using any HAP or HAP-based 
product as an ABA, as an option to reduce risks from this source 
category. Emissions of HAP ABA were shown to contribute

[[Page 66124]]

nearly 100 percent to the maximum individual cancer risks at the MACT-
allowable emissions level for this source category. This control option 
would require facilities to use ABAs that do not contain HAP. We 
estimate the HAP emissions reduction resulting from this control option 
would be approximately 735 tpy from the baseline MACT-allowable 
emissions level. We estimate there would be no costs associated with 
implementation of this option, as all facilities in the source category 
are reporting that they do not have HAP ABA emissions from the foam 
production line, and industry representatives have confirmed that all 
sources have already discontinued use of a HAP or HAP-based product as 
an ABA. Furthermore, there are no additional costs associated with the 
recordkeeping and reporting requirements for compliance. With this 
control option, we estimate the maximum cancer risks based on allowable 
emissions would be reduced from 5-in-1 million to less than 1-in-1 
million, the annual cancer incidence would be reduced from 0.0004 to 
0.00004, the acute HQ would be reduced from 4 to less than 1 and the 
non-cancer TOSHI would remain unchanged. We believe this HAP ABA 
prohibition is technically feasible for all slabstock FPUF production 
operations and is a cost-effective measure to achieve emissions and 
health risk reductions associated with the MACT-allowable level of 
emissions. Therefore, based on this analysis, we are proposing under 
section 112(f)(2) of the CAA to prohibit the use of HAP or HAP-based 
products as ABAs.
    We are proposing that the existing MACT standards, as modified to 
include the HAP-based ABA prohibition described above, will provide an 
ample margin of safety to protect public health and prevent an adverse 
environmental effect.
    For diisocyanate storage vessels, as discussed in section IV.C.2. 
of this preamble, we identified one control option to further reduce 
HAP emissions from these storage vessels, which were shown to 
contribute approximately 1 percent to the maximum individual cancer 
risks at the MACT-allowable emissions level for the source category. 
This control option would require sources to increase storage vessel 
HAP emissions control efficiencies to 98 percent, using technologies 
such as regenerative thermal oxidizers (RTO) or recuperative thermal 
oxidizers (RCO). We estimate the resulting HAP reduction would be 
approximately 0.0026 tpy from the baseline MACT-allowable emissions 
level. The estimated cost effectiveness per ton of HAP emissions 
reduction would be $124 million and $269 million, based on using a RTO 
and RCO, respectively. The additional control requirement would not 
achieve a reduction in the maximum individual cancer risks or any of 
the other risk metrics due to emissions at the MACT-allowable level. 
Due to the minimal reductions in HAP emissions and risk, along with the 
substantial costs associated with this option, we are proposing that 
additional HAP emissions controls for FPUF production diisocyanate 
storage vessels are not necessary to provide an ample margin of safety.
    For equipment leaks at slabstock foam production facilities, as 
discussed in section IV.C.3. of this preamble, we identified several 
control options to further address risks from leaking components. We 
estimate that up to 3 percent of the emissions and associated risk at 
the MACT-allowable levels could be attributed to equipment leaks.\22\ 
The control options identified include the use of ``leakless'' valves 
in diisocyanate service at slabstock facilities and implementation of 
an enhanced LDAR program for diisocyanate equipment leaks at slabstock 
facilities. These control options would require sources to use 
``leakless'' valve technology or implement a LDAR program that would 
incorporate monitoring with EPA Method 21, specific leak definitions, 
and possibly a limit on the total number of non-repairable equipment 
allowed. We estimate the HAP reduction resulting from the ``leakless'' 
valve technology would be 1 tpy from the baseline MACT-allowable 
emissions level, with a cost effectiveness of $305,000/ton HAP 
reduction. The HAP emissions reduction resulting from an enhanced LDAR 
program would be 0.38 tpy from the baseline MACT-allowable emissions 
level, with a cost effectiveness of approximately $74,000/ton HAP 
reduction. The HAP emissions reduction resulting from the portion of an 
enhanced LDAR program that incorporates limits on the total number of 
non-repairable equipment allowed would be 0.08 tpy from the baseline 
MACT-allowable emissions level, with a cost effectiveness of 
approximately $234,000/ton HAP emissions reduction. None of these 
additional control requirements for diisocyanate equipment leaks would 
achieve a reduction in the maximum individual cancer risks or any of 
the other health risk metrics. Due to the minimal reductions in HAP 
emissions and risk, along with the substantial costs associated with 
these options, we are proposing that additional HAP emissions controls 
for FPUF production diisocyanate equipment leaks are not necessary to 
provide an ample margin of safety.
---------------------------------------------------------------------------

    \22\ Hazardous Air Pollutant Emissions from the Production of 
Flexible Polyurethane Foam. Basis and Purpose Document for Proposed 
Standards.'' Page 6-9. U.S. EPA Office of Air Quality Planning and 
Standards. September 1996.
---------------------------------------------------------------------------

3. Adverse Environmental Effects
    We did not identify emissions of the seven environmental HAP 
included in our environmental risk screening, and are unaware of any 
adverse environmental effects caused by other HAP emitted by this 
source category. Therefore, we do not expect there to be an adverse 
environmental effect as a result of HAP emissions from this source 
category, and we are proposing that it is not necessary to set a more 
stringent standard to prevent, taking into consideration costs, energy, 
safety, and other relevant factors, an adverse environmental effect.

C. What are the results and proposed decisions based on our technology 
review?

    As described in section III.C of this preamble, our technology 
review focused on identifying developments in practices, processes and 
control technologies for the emission sources in the FPUF production 
source category. The following sections summarize our technology review 
results. More information concerning our technology review can be found 
in the memorandum titled, Technology Review and Cost Impacts for the 
Proposed Amendments to the Flexible Polyurethane Foam Production Source 
Category, which is available in the docket.
1. Slabstock Foam Production Line
    The current MACT standards allow limited use of HAP-based ABAs at 
slabstock foam production facilities, while prohibiting the use of HAP-
based products, with limited exceptions, for specific purposes at other 
types of FPUF production facilities (including equipment cleaning, 
mixhead flushing and facilitating mold release at molded and rebond 
foam facilities). The FPUF Production MACT standards also prohibit HAP 
and HAP-based products in equipment cleaners at slabstock foam 
facilities (except at facilities operating under the provisions for a 
source-wide emission limit for a single HAP ABA). Prohibiting the use 
of HAP-based ABAs and HAP-based equipment cleaners at slabstock foam 
production facilities has been identified as a development in

[[Page 66125]]

practices and/or processes that could reduce HAP emissions from the 
slabstock foam production line.
    At the time of promulgation of the FPUF MACT standards, the EPA 
believed that HAP ABAs were necessary for production of some grades of 
foam. Therefore, the FPUF Production MACT standards significantly 
limited the use of HAP ABAs by slabstock foam producers, but allowed 
their use in production of certain grades of foam.
    Available data from EPA databases, industry survey responses and 
contacts with state and local permitting agencies show that none of the 
13 facilities currently identified as being subject to the FPUF 
Production MACT standards are using any HAP ABAs, or ABAs containing 
HAP (i.e., HAP-based ABAs). Further confirmation was received through 
discussions with the Polyurethane Foam Association (PFA), a trade 
association representing the slabstock polyurethane foam production 
industry. Details of the discussion with PFA are contained in 
Documentation of Communications with Industry and Regulatory Agency 
Contacts for the Flexible Polyurethane Foam Industry, which is 
available in the docket for this rulemaking. The discontinuation of HAP 
ABAs (or HAP-based ABAs) use by FPUF producers demonstrates that foam 
producers have improved their ability to produce their products using 
alternatives to HAP or HAP-based ABAs since the promulgation of the 
original FPUF Production NESHAP.
    No facilities subject to subpart III are currently using any HAP or 
HAP-based ABAs. Therefore, there will be no cost associated with 
codifying current industry practice prohibiting the use of HAP or HAP-
based ABAs. There may be small cost savings at some facilities due to 
reduced monitoring and recordkeeping costs. Because there are no 
estimated costs, the industry is already complying with this HAP and 
HAP-based ABA prohibition in practice, and reductions in allowable 
emissions would be achieved, we are proposing that it is necessary, 
pursuant to CAA section 112(d)(6), to revise the MACT to prohibit the 
use of HAP and HAP-based ABAs at slabstock foam production facilities. 
As noted in section IV.B.2., we are concurrently proposing this HAP and 
HAP-based ABA prohibition under section 112(f)(2) of the CAA to provide 
an ample margin of safety to protect public health. Also, as noted in 
section II.B, we solicit comments regarding whether any facilities 
subject to subpart III currently use HAP or HAP-based ABAs.
2. Diisocyanate Storage Vessels
    The FPUF Production MACT standards provide two compliance options 
for diisocyanate storage vessels: Equip the storage vessels (tanks) 
with a vapor return line from the storage vessel to the truck or rail 
car during unloading; or equip the storage vessel with a carbon 
adsorption system which routes displaced vapors through activated 
carbon. These control systems are estimated to have control 
efficiencies of 95 percent. For the technology review, we identified 
two potential control options to capture and control emissions from 
storage tanks: Regenerative and recuperative thermal oxidizers. Both 
reportedly have control efficiencies of 98 percent, and known 
application to low concentration organic vapor gas streams. We estimate 
an additional emission reduction of 0.0026 tpy would be associated with 
an increase from 95 percent estimated HAP control in the original FPUF 
MACT standards to 98 percent HAP control today. The estimated cost per 
ton of emissions reduction would be $124 million and $270 million per 
ton of HAP for regenerative and recuperative thermal oxidizers, 
respectively.
    Based on the high costs and the minimal emissions reductions that 
would be achieved by these diisocyanate tank controls, we are proposing 
that it is not necessary to revise the MACT standards pursuant to CAA 
section 112(d)(6) to provide for a stricter level of control.
3. Equipment Leaks
    For equipment leaks, we identified two developments in practices, 
process or control technologies: Use of ``leakless'' valves in 
diisocyanate service at slabstock facilities and implementation of an 
enhanced equipment LDAR for diisocyanate equipment leaks at slabstock 
facilities. While there are requirements for LDAR in the original MACT 
standards, we further investigated LDAR for developments that have 
occurred since the rule was promulgated. The two developments in LDAR 
programs are a limit on the total number of non-repairable equipment 
allowed and the inclusion of lower leak detection limits for valves and 
connectors than those considered previously for the MACT standards.
a. ``Leakless'' Valves
    ``Leakless'' valves that significantly reduce emissions are in 
place in some facilities outside the FPUF production source category, 
particularly oil refineries. We analyzed the costs associated with 
requiring this ``leakless'' valve technology for valves in diisocyanate 
service in the FPUF production source category using cost estimates 
developed for the synthetic organic chemical manufacturing industry. 
Nationwide annual costs were estimated to be $310,000/yr, with total 
capital investments of $2,260,000. Emission reductions were estimated 
to be 1 tpy, resulting in a cost effectiveness of $305,000/ton HAP 
reduction.
    Based on the high costs and the minimal emissions reductions that 
would be achieved using this technology, we are proposing that it is 
not necessary to revise the MACT standards pursuant to CAA section 
112(d)(6) to require the installation of ``leakless'' valves.
b. Implementation of Enhanced LDAR Programs
    The current MACT standards require an LDAR program that employs 
visual, audible or other methods for detecting leaks. This standard 
requires repair of leaks within 15 calendar days when leaks are 
detected by visual, audible or any other detection method for 
equipment, other than transfer pumps, in diisocyanate service. Leakless 
technology is required for transfer pumps.
    During the development of the MACT standards, another LDAR program, 
using Method 21, was identified as a beyond-the-floor method for 
controlling emissions from equipment leaks at slabstock foam facilities 
for equipment in diisocyanate service, but was not chosen as the level 
of the standard. At that time, the leak definition was set at a HAP 
concentration of 10,000 ppm or greater. Since the development of the 
MACT standards, analyses have been performed by the EPA regarding costs 
and emission reductions in the chemical and petroleum industries 
associated with lowering the level at which a HAP concentration is 
considered to be a leak for LDAR programs.\23\ We used these analyses 
in the CAA section 112(d)(6) technology review for the FPUF production 
source category to assess the effects of adding an enhanced LDAR 
program for metering pumps, valves, connectors and open-ended lines in 
diisocyanate service at slabstock foam production facilities. The LDAR 
program would incorporate monitoring, employing Method 21 of 40 CFR 
part 60, Appendix A, and lower leak definitions. The lower leak 
definitions considered

[[Page 66126]]

include two options identified in the EPA analysis of emissions 
reduction techniques for equipment leaks:
---------------------------------------------------------------------------

    \23\ Memorandum from Cindy Hancy, RTI to Jodi Howard, EPA, 
Analysis of Emission Reduction Techniques for Equipment Leaks, 
December 21, 2011. (EPA-HQ-OAR-2002-0037-0180.) See Attachment 1.
---------------------------------------------------------------------------

    1. Leak definition for metering pumps of 2,000 ppm; leak definition 
for valves, connectors and open-ended lines of 500 ppm;
    2. Leak definition for valves of 100 ppm; leak definition for 
metering pumps, connectors and open-ended lines of 500 ppm.
    We analyzed the costs associated with an LDAR programs with these 
two options for leak definitions for equipment in diisocyanate service. 
For both options, nationwide total annual costs were estimated to be 
around $28,200/yr, with total capital investments of approximately 
$32,400. Reduction of HAP emissions were estimated to be about 0.38 
tpy, resulting in a cost effectiveness of approximately $74,000/ton HAP 
reduction.
    The current MACT standards allow leak repairs to be delayed under 
certain circumstances. Limits on the number of leaking components 
awaiting repair was also identified as a potential development in 
practice that could reduce diisocyanate emissions from equipment leaks. 
Both the California Bay Area Air Quality Management District (BAAQMD) 
and the South Coast Air Quality Management District have LDAR programs 
that limit the number of leaking equipment components awaiting repair. 
The BAAQMD rule also requires mass emission testing for leaking valves 
and requires valves with a high leak rate to be repaired within 7 days. 
We estimated the costs of requirements addressing equipment awaiting 
leak repair like those of the BAAQMD rule, irrespective of the other 
costs for an LDAR program. Nationwide annual costs were estimated to be 
$18,212/yr, with no capital investments required. Emission reductions 
were estimated to be 0.002 tpy, resulting in a cost effectiveness of 
$233,770 per ton of HAP reduction for equipment in diisocyanate service 
at slabstock facilities.
    Based on the high costs and the minimal emissions reduction that 
would be achieved with LDAR programs using Method 21 and either of the 
leak definition options, or with the restrictions on equipment awaiting 
repair, we are proposing that it is not necessary to revise the MACT 
standards pursuant to CAA section 112(d)(6) to require an enhanced LDAR 
program. However, we are adding a provision to the rule to clarify that 
delay of leak repairs for valves and connectors must be completed 
within 6 months of detection, as described in section IV.D.4.

D. What other actions are we proposing?

1. Startup, Shutdown and Malfunctions
a. Background
    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 (D.C. 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) holding 
that under section 302(k) of the CAA, emissions standards or 
limitations must be continuous in nature and that the SSM exemption 
violates the CAA's requirement that some section 112 standards apply 
continuously.
    We are proposing the elimination of the SSM exemption in this 
proposed rule. Therefore, this proposed rule has changed the indication 
of ``Yes'' to ``No'' in the General Provisions table (Table 2) of this 
rule for Sec.  63.6(f), in which Sec.  63.6(f)(1) states, ``The non-
opacity emission standards set forth in this part shall apply at all 
times except during periods of startup, shutdown, and malfunction. . . 
.'' Consistent with Sierra Club v. EPA, the EPA is proposing standards 
in this rule that apply at all times. We are also proposing several 
revisions to Table 2 (Applicability of General Provisions), as is 
explained in more detail below. We also are proposing to eliminate and 
revise certain recordkeeping and reporting requirements related to the 
SSM exemption as further described below.
    The EPA has attempted to ensure that the provisions we are 
proposing to eliminate are inappropriate, unnecessary, or redundant in 
the absence of the SSM exemption. We are specifically seeking comment 
on whether we have successfully done so.
    In proposing the standards in this rule, the EPA has taken into 
account startup and shutdown periods and, for the reasons explained 
below, has not proposed alternate standards for those periods. 
Information on periods of startup and shutdown received from the 
facilities in the FPUF production industry indicate that emissions 
during these periods are the same as during normal operations. The 
primary means of compliance with the standards are through work 
practices and product substitutions, which eliminate the use of HAP, 
and are in place at all times. Therefore, separate standards for 
periods of startup and shutdown are not necessary and are not being 
proposed.
    Periods of startup, normal operations 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 CAA 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 CAA 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 case law, nothing in that case law requires 
the agency to consider malfunctions as part of that analysis. Section 
112 of the CAA 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 (D.C. 
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 (D.C. Cir. 1978) (``In the nature of things, no

[[Page 66127]]

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 CAA section 112 and is a reasonable interpretation of the statute.
    In the unlikely 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 a violation of the relevant emission standard. See, 
e.g., State Implementation Plans: Response to Petition for Rulemaking; 
Findings of Excess Emissions During Periods of Startup, Shutdown, and 
Malfunction; Proposed rule, 78 FR 12460 (Feb. 22, 2013); 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 add an affirmative 
defense to civil penalties for violations of emission standards that 
are caused by malfunctions. (See 40 CFR 63.1292 defining ``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 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 Sec.  63.1290(e) (See 40 
CFR 22.24). The criteria are designed in part to ensure that the 
affirmative defense is available only where the event that causes a 
violation of the emission standard meets the narrow definition of 
malfunction in Sec.  63.2 (sudden, infrequent, not reasonably 
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 
the violation ``[w]as caused by a sudden, infrequent, and unavoidable 
failure of air pollution control, 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 section 63.1290(d) 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 a violation occurred. . .'' and that 
``[a]ll possible steps were taken to minimize the impact of the 
violation 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 CAA section 113 (see also 40 CFR 22.27).
    The EPA included an affirmative defense in the proposed rule 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 standards may be 
violated 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 emissions 
standards are continuous. The affirmative defense for malfunction 
events meets this requirement by ensuring that even where there is a 
malfunction, the emission standard is still enforceable through 
injunctive relief. The United States Court of Appeals for the Fifth 
Circuit recently upheld the EPA's view that an affirmative defense 
provision is consistent with CAA section 113(e). Luminant Generation 
Co. LLC v. United States EPA, 714 F.3d 841 (5th Cir. Mar. 25, 2013) 
(upholding the EPA's approval of affirmative defense provisions in a 
CAA State Implementation Plan). While ``continuous'' standards, on the 
one hand, are required, there is also case law 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 DC 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 case law, such as Sierra Club v. EPA and the CAA 1977 
amendments, call into question 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 violations that are proven to be 
beyond the control of the source. By incorporating an affirmative 
defense, the EPA has formalized its approach to malfunctions. 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 also, Mont. Sulphur & Chem. Co. v. EPA, 666 F.3d. 1174 
(9th Cir. 2012) (rejecting industry argument that reliance on the 
affirmative defense was not adequate). But 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 standards are 
``continuous'' as required by 42 U.S.C. 7602(k), and account for 
unplanned upsets and thus

[[Page 66128]]

support the reasonableness of the standard as a whole. The EPA is 
proposing the affirmative defense applicable to malfunctions under the 
delegation of general regulatory authority set out in CAA section 
301(a)(1), 42 U.S.C. 7601(a)(1), in order to balance this tension 
between provisions of the CAA and the practical reality, as case law 
recognizes, that technology sometimes fails. See generally Citizens to 
Save Spencer County v. U.S. Environmental Protection Agency, 600 F.2d 
844, 873 (D.C. Cir. 1979) (using CAA section 301(a) authority to 
harmonize inconsistent guidelines related to the implementation of 
federal preconstruction review requirements).
b. Specific SSM-Related Proposed Changes
    To address the United States Court of Appeals for the District of 
Columbia Circuit vacatur of portions of the EPA's CAA section 112 
regulations governing the emissions of HAP during periods of SSM, we 
are revising and adding certain provisions to the FPUF Production rule. 
As described in detail below, we are revising the General Provisions 
(Table 2) to change several of the references related to requirements 
that apply during periods of SSM. We are also adding the following 
provisions to the FPUF Production rule: (1) The general duty to 
minimize emissions at all times, (2) the requirement for sources to 
comply with the emission limits in the rule at all times, and (3) 
malfunction recordkeeping and reporting requirements.
i. Sec.  63.1290(d)(4) General Duty
    We are proposing to revise the General Provisions table (Table 2) 
entry for Sec.  63.6(e)(1)-(2) by adding rows specifically for Sec.  
63.6(e)(1)(i), 63.6(e)(1)(ii) and 63.6(e)(1)(iii) and to include a 
``no'' in the second column for the Sec.  63.6(e)(1)(i) entry. Section 
63.6(e)(1)(i) describes the general duty to minimize emissions. Some of 
the language in that section is no longer necessary or appropriate in 
light of the elimination of the SSM exemption. We are proposing instead 
to add general duty regulatory text at Sec.  63.1290(d)(4) that 
reflects the general duty to minimize emissions while eliminating the 
reference to periods covered by an SSM exemption. The current language 
in 40 CFR 63.6(e)(1)(i) characterizes what the general duty entails 
during periods of SSM. With the elimination of the SSM exemption, there 
is no need to differentiate between normal operations, startup and 
shutdown, and malfunction events in describing the general duty. 
Therefore the language the EPA is proposing does not include that 
language from Sec.  63.6(e)(1).
    We are also proposing to include a ``no'' in the second column for 
the newly added Sec.  63.6(e)(1)(ii) entry. Section 63.6(e)(1)(ii) 
imposes requirements that are not necessary with the elimination of the 
SSM exemption or are redundant of the general duty requirement being 
added at Sec.  63.1290(d)(4).
ii. Compliance With Standards
    We are proposing to revise the General Provisions table (Table 2) 
entry for Sec.  63.6(f) by adding a specific entry for Sec.  63.6(f)(1) 
and including a ``no'' in the second column for this Sec.  63.6(f)(1) 
entry. The current language of section 63.6, paragraph (f)(1) exempts 
sources from non-opacity standards during periods of SSM. As discussed 
above, the court in Sierra Club vacated the exemptions contained in 
this provision and held that the CAA requires that some CAA section 112 
standard apply continuously. Consistent with Sierra Club, the EPA is 
proposing to revise standards in this rule to apply at all times.
iii. Sec.  63.1307(h) Recordkeeping
    We are proposing to revise the General Provisions table (Table 2) 
entry for Sec.  63.10(a)-(b) by adding rows specifically for Sec.  
63.10(a), 63.10(b)(1), 63.10 (b)(2)(i), 63.10 (b)(2)(ii), 63.10 
(b)(2)(iii), 63.10 (b)(2)(iv)-(xi), 63.10 (b)(2)(xii), 63.10 (b)(xiii), 
and 63.10 (b)(2)(xiv) in order to specify changes we are making to the 
applicability of several of the Sec.  63.10(b)(2) paragraphs. In the 
entry for Sec.  63.10(b)(2)(i), we are including a ``no'' in the second 
column. Section 63.10(b)(2)(i) describes the recordkeeping requirements 
during startup and shutdown. These recording provisions are no longer 
necessary because the EPA is proposing that recordkeeping and reporting 
applicable to normal operations will apply to startup and shutdown. In 
the absence of special provisions applicable to startup and shutdown, 
such as a startup and shutdown plan, there is no reason to retain 
additional recordkeeping for startup and shutdown periods.
    In the entry for Sec.  63.10(b)(2)(ii), we are including a ``no'' 
in the second column. Section 63.10(b)(2)(ii) describes the 
recordkeeping requirements during a malfunction. The EPA is proposing 
to add such requirements to 40 CFR 63.1307(h). The regulatory text we 
are proposing to add differs from the General Provisions it is 
replacing in that the General Provisions requires the creation and 
retention of a record of the occurrence and duration of each 
malfunction of process, air pollution control, and monitoring 
equipment. The EPA is proposing that this requirement apply to any 
failure to meet an applicable standard and is requiring that the source 
record the date, time, and duration of the failure rather than the 
``occurrence.'' The EPA is also proposing to add to Sec.  63.1307(h) a 
requirement that sources keep records that include a list of the 
affected sources or equipment and actions taken to minimize emissions, 
an estimate of the volume of each regulated pollutant emitted over the 
standard for which the source failed to meet a standard, and a 
description of the method used to estimate the emissions. Examples of 
such methods would include product-loss calculations, mass balance 
calculations, measurements when available, or engineering judgment 
based on known process parameters. The EPA is proposing to require that 
sources keep records of this information to ensure that there is 
adequate information to allow the EPA to determine the severity of any 
failure to meet a standard, and to provide data that may document how 
the source met the general duty to minimize emissions when the source 
has failed to meet an applicable standard.
    We are including a ``no'' in the second column in the entry for 
Sec.  63.10(b)(2)(iv) and 63.10(b)(2)(v). When applicable, the 
provisions require sources to record actions taken during SSM events 
when actions were inconsistent with their SSM plan. These requirements 
are not appropriate because SSM plans are not (and were not) required 
by this rule, and the General Provisions applicability table referenced 
these sections in error.
iv. Sec.  63.1306(f) Reporting
    We are proposing to revise the General Provisions table (Table 2) 
entry for Sec.  63.10(d)(4)-(5) by adding a specific entry for Sec.  
63.10(d)(5) and including a ``no'' in the second column for this Sec.  
63.10(d)(5) entry. Section 63.10(d)(5) describes the reporting 
requirements for startups, shutdowns, and malfunctions. To replace the 
General Provisions reporting requirement, the EPA is proposing to add 
reporting requirements to 40 CFR 63.1306(f). The replacement language 
differs from the General Provisions requirement in that it eliminates 
periodic SSM reports as a stand-alone report. We are proposing language 
that requires sources that fail to meet an applicable standard at any 
time to report the information concerning such events in the semi-
annual report for slabstock affected sources and in the annual 
compliance

[[Page 66129]]

certification for molded and rebond affected sources, which are already 
required under this rule. We are proposing that the malfunction report 
must contain the number, date, time, duration, and the cause of such 
events (including unknown cause, if applicable), a list of the affected 
sources or equipment, an estimate of the volume of each regulated 
pollutant emitted over any emission limit, and a description of the 
method used to estimate the emissions.
    Examples of such methods would include product-loss calculations, 
mass balance calculations, measurements when available, or engineering 
judgment based on known process parameters. The EPA is proposing this 
requirement to ensure that there is adequate information to determine 
compliance, to allow the EPA to determine the severity of the failure 
to meet an applicable standard, and to provide data that may document 
how the source met the general duty to minimize emissions during a 
failure to meet an applicable standard.
    The proposed rule eliminates the cross reference to section 
63.10(d)(5)(i) that contains the description of the previously required 
SSM report format and submittal schedule from this section. These 
specifications are no longer necessary because the events will be 
reported in otherwise required reports with similar format and 
submittal requirements.
    We note that reporting a failure to meet an applicable standard 
could include malfunction events for which a source may choose to 
submit documentation to support an assertion of affirmative defense. If 
a source provides all the material required in section 63.1290(e) to 
support an affirmative defense, the source need not submit the same 
information two times in the same report. While assertion of an 
affirmative defense is not mandatory and occurs only if a source 
chooses to take advantage of the affirmative defense, the affirmative 
defense also requires additional reporting that goes beyond these 
routine requirements related to a failure to meet an applicable 
standard for a reason other than a malfunction.
    The proposed rule also eliminates the cross-reference to section 
63.10(d)(5)(ii). Section 63.10(d)(5)(ii) describes an immediate report 
for startups, shutdown, and malfunctions when a source failed to meet 
an applicable standard but did not follow the SSM plan. These 
requirements are not appropriate because SSM plans are not required by 
this rule, and the General Provisions applicability table referenced 
this section in error.
2. Electronic Reporting of Performance Test Data
    In this proposal, the EPA is describing a process to increase the 
ease and efficiency of performance test data submittal while improving 
data accessibility. Specifically, the EPA is proposing that owners and 
operators of FPUF production facilities submit electronic copies of 
required performance test reports by direct computer-to-computer 
electronic transfer using EPA-provided software. The direct computer-
to-computer electronic transfer is accomplished through the EPA's 
Central Data Exchange (CDX) using the Compliance and Emissions Data 
Reporting Interface (CEDRI). The CDX is EPA's portal for submittal of 
electronic data. The EPA-provided software is called the Electronic 
Reporting Tool (ERT) which is used to generate electronic reports of 
performance tests and evaluations. The ERT generates an electronic 
report package which will be submitted using the CEDRI. The submitted 
report package will be stored in the CDX archive (the official copy of 
record) and EPA's public database called WebFIRE. All stakeholders will 
have access to all reports and data in WebFIRE and accessing these 
reports and data will be very straightforward and easy (see the WebFIRE 
Report Search and Retrieval link at http://cfpub.epa.gov/webfire/index.cfm?action=fire.searchERTSubmission). A description and 
instructions for use 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 
(www.epa.gov/cdx). A description of the WebFIRE database is available 
at: http://cfpub.epa.gov/oarweb/index.cfm?action=fire.main.
    The proposal to submit performance test data electronically to the 
EPA applies only to those performance tests conducted using test 
methods that are supported by the ERT. The ERT supports 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. Specifically, by using this approach, 
industry will save time in the performance test submittal process. 
Additionally, the standardized format that the ERT uses allows sources 
to create a more complete test report resulting in less time spent on 
data backfilling if a source failed to include all data elements 
required to be submitted. Also through this proposal industry may only 
need to submit a report once to meet the requirements of the applicable 
subpart because stakeholders can readily access these reports from the 
WebFIRE database. This also benefits industry by cutting back on 
recordkeeping costs as the performance test reports that are submitted 
to the EPA using CEDRI are no longer required to be retained in hard 
copy, thereby, reducing staff time needed to coordinate these records.
    Since the EPA will already have performance test data in hand, 
another benefit to industry is that fewer or less substantial data 
collection requests in conjunction with prospective required residual 
risk assessments or technology reviews will be needed. This would 
result in a decrease in staff time needed to respond to data collection 
requests.
    State, local and tribal air pollution control agencies (S/L/Ts) may 
also benefit from having electronic versions of the reports they are 
now receiving. For example, S/L/Ts may be able to conduct a more 
streamlined and accurate review of electronic data submitted to them. 
For example, the ERT would allow for an electronic review process, 
rather than a manual data assessment, therefore, making review and 
evaluation of the source provided data and calculations easier and more 
efficient. In addition, the public stands to benefit from electronic 
reporting of emissions data because the electronic data will be easier 
for the public to access. How the air emissions data are collected, 
accessed and reviewed will be more transparent for all stakeholders.
    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 proposed rule. The 
ERT clearly states what testing information would be required by the 
test method and has the ability to house additional data elements that 
might be required by a delegated authority.
    In addition the EPA must have performance test data to conduct 
effective reviews of CAA sections 111, 112 and 129 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. In recent

[[Page 66130]]

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.
    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. 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.
    Finally, the general public would also benefit from electronic 
reporting of emissions data because the data would be available for 
viewing sooner and would be easier for the public to access. The EPA 
Web site that stores the submitted electronic data will be easily 
accessible to the public and will provide a user-friendly interface 
that any stakeholder could access.
    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 air quality regulations. Electronic 
databases will also benefit the general public by improving 
accessibility to emissions data in an efficient and timely manner.
3. Clarification to Diisocyanate Storage Vessels Leak Detection Methods
    The EPA is proposing to clarify the leak detection methods that may 
be used for diisocyanate storage vessels at slabstock foam production 
facilities during unloading events. The current requirements allow the 
vapor return line to be inspected for leaks during unloading events 
using visual, audible or any other detection method. Today, the EPA is 
proposing to clarify, that ``any other detection method'' must be an 
instrumental detection method.
4. Clarification to Diisocyanate Equipment Leak Delay of Repair 
Requirements for Valves and Connectors
    The FPUF Production MACT standards generally require equipment 
leaks to be repaired within 15 days. However, there are also provisions 
that allow for a delay of repair. A delay of repair for pumps is 
allowed if repair requires replacing the existing seal design with a 
sealless pump, and the repair is completed as soon as practicable, but 
not later than 6 months after the leak is detected. For valves and 
connectors, a delay of repair is allowed if the owner or operator 
determines that diisocyanate emissions of purged material resulting 
from immediate repair are greater than the fugitive emissions likely to 
result from a delay of repair. However, for valves and connectors, the 
current provisions do not state how long such a delay may last. To be 
consistent with the requirements for pumps, we are proposing to clarify 
that, for valves and connectors, the repair must be completed as soon 
as practicable, but not later than 6 months after the leak was 
detected.

E. What compliance dates are we proposing?

    We are proposing that FPUF production facilities comply with the 
new proposed requirements prohibiting the use of HAP ABAs in this 
action no later than 90 days after the effective date of the final 
rule. This time period will be sufficient because all FPUF production 
facilities have already discontinued use of HAP ABAs.
    We are proposing that facilities must comply with the SSM reporting 
and recordkeeping requirements and affirmative defense provisions, and 
requirements for electronic reporting on the effective date of the 
rule. We are proposing these compliance dates because the revised SSM 
requirements should be immediately implementable by the facilities upon 
the next occurrence of a malfunction, and the electronic reporting 
requirements should be immediately implementable by the facilities upon 
their next performance test.

V. Summary of Cost, Environmental and Economic Impacts

A. What are the affected sources?

    We anticipate that 13 FPUF production facilities currently 
operating in the United States will be affected by these proposed 
amendments. We also expect no new facilities to be constructed in the 
foreseeable future. For more information about expected new facilities, 
see the document titled, Documentation of Communications with Industry 
and Regulatory Agency Contacts for the Flexible Polyurethane Foam 
Industry, located in the docket for this action.

B. What are the air quality impacts?

    The EPA estimates that the proposed amendments to the FPUF 
Production MACT standards will not result in any directly quantifiable 
reduction of HAP emissions. Emissions of HAP from FPUF production 
sources have significantly declined since promulgation of the FPUF 
Production MACT standards because HAP ABAs are no longer used by FPUF 
production facilities. However, as discussed in section III.A.2, the 
MACT standards currently allow sources to use HAP ABAs. We estimate 
that the MACT-allowable emissions for the FPUF production source 
category are 735 tons of HAP ABAs. If the proposed revision prohibiting 
the use of HAP ABAs is finalized, the MACT-allowable emissions from ABA 
use would be zero. A detailed documentation of the analysis can be 
found in: MACT-Allowable Emissions for the Flexible Polyurethane Foam 
Production Source Category, which is available in the docket for this 
rulemaking.

C. What are the cost impacts?

    Under the proposed amendments, FPUF production facilities are not 
expected to incur any costs. However, there may be small cost savings 
at some facilities due to reduced monitoring and recordkeeping costs. 
The memorandum, Technology Review and Cost Impacts for the Proposed 
Amendments to the Flexible Polyurethane Foam Production Source 
Category, includes a complete description of the cost estimate methods 
used for the analyses related to the proposed HAP and HAP-based ABA 
prohibition and is available in the docket.

D. What are the economic impacts?

    Because no costs or a small cost savings are expected as a result 
of the proposed amendments, there will not be any significant impacts 
on affected firms and their consumers as a result of this proposal.
    Because no small firms face significant control costs, there is no 
significant impact on small entities. Thus, this regulation is not 
expected to have a significant impact on a substantial number of small 
entities.

E. What are the benefits?

    We do not anticipate any significant actual emission reductions of 
HAP as a result of these proposed amendments. However, if finalized, 
the proposed prohibition on HAP ABA use would eliminate the possibility 
that facilities

[[Page 66131]]

might begin to use HAP ABAs again. Under the existing rule, those 
possible emissions are estimated at 735 tons of HAP ABAs. If the 
prohibition is adopted, no emissions of HAP ABA would be allowed by the 
standard.

VI. Request for Comments

    We solicit comments on all aspects of this proposed action. In 
addition to general comments on this proposed action, we are also 
interested in additional data that may improve the risk assessments and 
other analyses. We are specifically interested in receiving any 
improvements to the data used in the site-specific emissions profiles 
used for risk modeling. Such data should include supporting 
documentation in sufficient detail to allow characterization of the 
quality and representativeness of the data or information. Section VII 
of this preamble provides more information on submitting data.

VII. Submitting Data Corrections

    The site-specific emissions profiles used in the source category 
risk and demographic analyses and instructions are available on the RTR 
Web page at: http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. The data 
files include detailed information for each HAP emissions release point 
for the facilities in the source category.
    If you believe that the data are not representative or are 
inaccurate, please identify the data in question, provide your reason 
for concern and provide any ``improved'' data that you have, 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 page, complete the following steps:
    1. Within this downloaded file, enter suggested revisions to the 
data fields appropriate for that information.
    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 Number EPA-HQ-OAR-2012-0510 (through one of the methods 
described in the ADDRESSES section of this preamble).
    5. If you are providing comments on a single facility or multiple 
facilities, you need only submit one file for all facilities. The file 
should contain all suggested changes for all sources at that facility. 
We request that all data revision comments be submitted in the form of 
updated Microsoft[supreg] Excel files that are generated by the 
Microsoft[supreg] Access file. These files are provided on the RTR Web 
page at: http://www.epa.gov/ttn/atw/rrisk/rtrpg.html.

VIII. Statutory and Executive Order Reviews

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

    This action is not a ``significant regulatory action'' under the 
terms of Executive Order 12866 (58 FR 51735, October 4, 1993) and is 
therefore not subject to review under Executive Orders 12866 and 13563 
(76 FR 3821, January 21, 2011).

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 Request (ICR) 
document prepared by the EPA has been assigned EPA ICR number 1783.07.
    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.
    For this proposed rule, the EPA is adding affirmative defense to 
the estimate of burden in the ICR. 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 $2,188 
for the FPUF production source category, and is based on the time and 
effort 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. With respect to the FPUF production source 
category, we estimate the annual recordkeeping and reporting burden 
after the effective date of the proposed rule for affirmative defense 
to be 30 hours at a cost of $2,188. We expect to gather information on 
such events in the future and will revise this estimate as better 
information becomes available.
    We estimate approximately 13 regulated entities are currently 
subject to 40 CFR part 63, subpart III, and will be subject to all 
proposed standards, a decrease of 119 regulated entities from our 
estimate for the previous ICR (EPA ICR Number 1783.05, OMB Control 
Number 2060-0357) for the FPUF production source category. The annual 
monitoring, reporting, and recordkeeping burden for this collection 
(averaged over the first 3 years after the

[[Page 66132]]

effective date of the standards) for subpart III (FPUF production), 
including today's proposed amendments, is estimated to be $90,104 per 
year. This includes 1,030 labor hours per year at a total labor cost of 
$90,104 per year, and total non-labor capital and operation and 
maintenance costs of $0 per year. This represents a decrease of 
$760,000 and 8,000 labor hours from the previous ICR, due primarily to 
the reduction in the estimated number of regulated entities. Our 
estimate of the burden for each regulated entity has increased by $485 
and 11 labor hours from the previous ICR estimate. This increase in 
burden for each regulated entity is not due to the proposed amendments, 
but is due to a correction of an error in the total number of reports 
required per year for slabstock foam producers. This was previously 
estimated to be two semi-annual reports per year, but this estimate did 
not account for the annual compliance report.
    The total burden for the federal government (averaged over the 
first 3 years after the effective date of the standard) is estimated to 
be 67 hours per year at a total labor cost of $3,607 per year. Burden 
is defined at 5 CFR 1320.3(b). 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.
    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-2012-0510. 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 November 4, 2013, a comment to OMB is best 
assured of having its full effect if OMB receives it by December 4, 
2013. 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.
    After considering the economic impacts of today's proposed rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. The small 
entities directly regulated by this proposed rule are small businesses. 
We have determined that three facilities, or 23 percent of the 13 
affected facilities, are small entities. Total annualized costs for the 
proposed rule are estimated to be $0, and no small entities are 
projected to incur costs. Because HAP ABAs are no longer used by FPUF 
production facilities, there are no impacts on any entities subject to 
this rulemaking.
    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 action contains no 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. This action imposes no enforceable duties on any state, local 
or tribal governments or the private sector. Therefore, this action is 
not subject to the requirements of sections 202 or 205 of the UMRA.
    This action 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 action does not have federalism implications. It will 
not have substantial direct effects on the states, on the relationship 
between the national government and the states, or on the distribution 
of power and responsibilities among the various levels of government, 
as specified in Executive Order 13132. This action will not impose 
substantial direct compliance costs on state or local governments, nor 
will it preempt state law, and none of the facilities subject to this 
action are owned or operated by state governments. Thus, Executive 
Order 13132 does not apply to this action.
    In the spirit of Executive Order 13132, and consistent with the EPA 
policy to promote communications between the EPA and state and local 
governments, the EPA specifically solicits comment on this action from 
state and local officials.

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

    This action does not have tribal implications, as specified in 
Executive Order 13175 (65 FR 67249, November 9, 2000). There are no 
FPUF production facilities that are within 3 miles of tribal lands. 
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 action is not subject to Executive Order 13045 (62 FR 19885, 
April 23, 1997) because it is not economically significant as defined 
in Executive Order 12866, and because the agency does not believe the 
environmental health risks or safety risks addressed by this action 
present a disproportionate risk to children. This proposed action's 
health and risk assessments are contained in section IV of this 
preamble.
    The public is invited to submit comments or identify peer-reviewed 
studies and data that assess effects of early life exposure to HAP 
emitted by FPUF production facilities.

[[Page 66133]]

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 in 
Executive Order 13211 (66 FR 28355 (May 22, 2001)), because it is not 
likely to have a significant adverse effect on the supply, 
distribution, or use of energy. We have concluded that this rule is not 
likely to have any adverse energy effects because the proposed 
requirements of this rule will not cause the additional use of energy 
by any facilities in the source category nor is there any expected 
impact on sources in the energy supply, distribution, or use sectors 
related to the proposed provisions of this rule.

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 voluntary 
consensus standards bodies. NTTAA directs the EPA to provide Congress, 
through OMB, explanations when the agency decides not to use available 
and applicable VCS.
    The proposed rulemaking involves technical standards. Therefore, 
the agency conducted a search to identify potentially applicable 
voluntary consensus standards. However, we identified no such 
standards, and none were brought to our attention in comments. 
Therefore, the EPA has decided to use EPA Method 25A, ``Determination 
of Total Gaseous Organic Concentration Using a Flame Ionization 
Analyzer,'' 40 CFR part 60, Appendix A, to measure organic compound 
concentrations.
    EPA welcomes comments on this aspect of the proposed rulemaking 
and, specifically, invites the public to identify potentially-
applicable voluntary consensus standards and to explain why such 
standards should be used in this regulation.

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.
    The EPA has determined that this proposed rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations, because it increases the 
level of environmental protection for all affected populations without 
having any disproportionately high and adverse human health or 
environmental effects on any population, including any minority or low-
income population.
    To gain a better understanding of the source category and near 
source populations, the EPA conducted a proximity analysis on FPUF 
production facilities to identify any overrepresentation of minority, 
low income or indigenous populations. This analysis only gives some 
indication of the prevalence of sub-populations that may be exposed to 
air pollution from the sources; it does not identify the demographic 
characteristics of the most highly affected individuals or communities, 
nor does it quantify the level of risk faced by those individuals or 
communities. More information on the source category's risk can be 
found in section IV of this preamble.
    The proximity analysis reveals that most demographic categories are 
below or within 20 percent of their corresponding national averages. 
The one exception is the African American population. The ratio of 
African Americans living within 3 miles of any source affected by this 
rule is 48 percent higher than the national average (19 percent versus 
13 percent); however, as noted previously, risks from this source 
category were found to be acceptable for all populations. Additionally, 
the proposed changes to the standard increase the level of 
environmental protection for all affected populations by ensuring no 
future emissions increases from the source category. The proximity 
analysis results and the details concerning their development are 
presented in the August 2012 memorandum titled, Environmental Justice 
Review: Flexible Polyurethane Foam Production, a copy of which is 
available in the docket for this action (EPA-HQ-OAR-2012-0510).

List of Subjects in 40 CFR Part 63

    Environmental protection, Air pollution control, Hazardous 
substances, Reporting and recordkeeping requirements.

    Dated: September 26, 2013.
Gina McCarthy,
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]

0
1. The authority citation for part 63 continues to read as follows:

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

Subpart III--National Emission Standards for Hazardous Air 
Pollutants for Flexible Polyurethane Foam Production

0
2. Section 63.1290 is amended by:
0
a. Revising paragraph (c); and
0
b. Adding paragraphs (d) and (e).
    The additions and revisions read as follows:

Sec.  63.1290  Applicability.

* * * * *
    (c) A process meeting one of the following criteria listed in 
paragraphs (c)(1) and (2) of this section shall not be subject to the 
provisions of this subpart:
    (1) A process exclusively dedicated to the fabrication of flexible 
polyurethane foam; or
    (2) A research and development process.
    (d) 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) Equipment leak requirements of Sec.  63.1294 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 the 
equipment leak requirements apply.
    (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 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

[[Page 66134]]

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. The general duty to minimize emissions does not require the 
owner or operator to make any further efforts to reduce emissions if 
levels required by the applicable standard have been achieved. 
Determination of whether a source is operating in compliance with 
operation and maintenance requirements 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.
    (e) Affirmative defense for violation of emission standards during 
malfunction. In response to an action to enforce the standards set 
forth in paragraphs Sec. Sec.  63.1293, 63.1294, 63.1297, 63.1298, 
63.1300, and 63.1301, the owner or operator may assert an affirmative 
defense to a claim for civil penalties for violations of such standards 
that are caused by malfunction, as defined at 40 CFR 63.2. Appropriate 
penalties may be assessed 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) Assertion of affirmative defense. To establish the affirmative 
defense in any action to enforce such a standard, the owner or operator 
must timely meet the reporting requirements in paragraph (e)(2) of this 
section, and must prove by a preponderance of evidence that:
    (i) The violation:
    (A) Was caused by a sudden, infrequent, and unavoidable failure of 
air pollution control 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) Was not part of a recurring pattern indicative of inadequate 
design, operation, or maintenance; and
    (ii) Repairs were made as expeditiously as possible when a 
violation occurred; and
    (iii) The frequency, amount, and duration of the violation 
(including any bypass) were minimized to the maximum extent 
practicable; and
    (iv) If the violation 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 
violation 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 violation 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 violation resulting from the malfunction event 
at issue. The analysis shall also specify, using best monitoring 
methods and engineering judgment, the amount of any emissions that were 
the result of the malfunction.
    (2) Report. The owner or operator seeking to assert an affirmative 
defense shall submit a written report to the Administrator with all 
necessary supporting documentation, that explains how it has met the 
requirements set forth in paragraph (e)(1) of this section. This 
affirmative defense report shall be included in the first periodic 
compliance, deviation report or excess emission report otherwise 
required after the initial occurrence of the violation of the relevant 
standard (which may be the end of any applicable averaging period). If 
such compliance, deviation report or excess emission report is due less 
than 45 days after the initial occurrence of the violation, the 
affirmative defense report may be included in the second compliance, 
deviation report or excess emission report due after the initial 
occurrence of the violation of the relevant standard.
0
3. Section 63.1291 is amended by revising paragraph (a) to read as 
follows:

Sec.  63.1291  Compliance schedule.

    (a) Existing affected sources shall be in compliance with all 
provisions of this subpart no later than October 8, 2001, with the 
exception of Sec.  63.1297. Affected sources subject to the 
requirements of Sec.  63.1297 shall be in compliance with the 
requirements of this section on or before [DATE 90 DAYS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER].
* * * * *
0
4. Section 63.1292 is amended by:
0
a. Adding a definition for ``affirmative defense'' in alphabetical 
order;
0
b. Revising the definitions for ``HAP-based,'' ``Reconstructed 
source,'' ``Storage vessel'' and ``Transfer pump''; and
0
c. Removing the definitions for ``High-pressure mixhead,'' 
``Indentation Force Deflection (IFD),'' ``In HAP ABA service,'' 
``Recovery device,'' ``Run of foam,'' and ``Transfer vehicle''.
    The additions and revisions read as follows:

Sec.  63.1292  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.
* * * * *
    HAP-based means to contain 5 percent (by weight) or more of HAP. 
This applies to equipment cleaners, mixhead flushes, mold release 
agents and ABA.
* * * * *
    Reconstructed source means an affected source undergoing 
reconstruction, as defined in subpart A of this part. For the purposes 
of this subpart, process modifications made to stop using HAP ABA or 
HAP-based ABA to meet the requirements of this subpart shall not be 
counted in determining whether or not a change or replacement meets the 
definition of reconstruction.
* * * * *
    Storage vessel means a tank or other vessel that is used to store 
diisocyanates for use in the production of flexible polyurethane foam. 
Storage vessels do not include vessels with capacities smaller than 38 
cubic meters (or 10,000 gallons).
    Transfer pump means all pumps used to transport diisocyanates that 
are not metering pumps.
0
5. Section 63.1293 is revised to read as follows:

Sec.  63.1293  Standards for slabstock flexible polyurethane foam 
production.

    Each owner or operator of a new or existing slabstock affected 
source shall comply with Sec. Sec.  63.1294, 63.1297 and 63.1298.
0
6. Section 63.1294 is amended by revising paragraphs (a)(1)(i), (c) and

[[Page 66135]]

(d)(2)(ii), and by adding paragraph (d)(2)(iii) to read as follows:

Sec.  63.1294  Standards for slabstock flexible polyurethane foam 
production--diisocyanate emissions.

    (a) * * *
    (1) * * *
    (i) During each unloading event, the vapor return line shall be 
inspected for leaks by visual, audible, or an instrumental detection 
method.
* * * * *
    (c) Other components in diisocyanate service. If evidence of a leak 
is found by visual, audible, or an instrumental detection method, it 
shall be repaired as soon as practicable, but not later than 15 
calendar days after it is detected, except as provided in paragraph (d) 
of this section. The first attempt at repair shall be made no later 
than 5 calendar days after each leak is detected.
    (d) * * *
    (2) * * *
    (ii) The purged material is collected and destroyed or recovered in 
a control device when repair procedures are effected, and
    (iii) Repair is completed as soon as practicable, but not later 
than 6 months after the leak was detected.
* * * * *

Sec.  63.1295  [Removed and Reserved]

0
7. Remove and reserve Sec.  63.1295.

Sec.  63.1296  [Removed and Reserved]

0
8. Remove and reserve Sec.  63.1296.
0
9. Revise Sec.  63.1297 to read as follows:

Sec.  63.1297  Standards for slabstock flexible polyurethane foam 
production--HAP ABA.

    Each owner or operator of a new or existing slabstock affected 
source shall not use HAP or a HAP-based material as an ABA.
0
10. Revise Sec.  63.1298 to read as follows:

Sec.  63.1298  Standards for slabstock flexible polyurethane foam 
production--HAP emissions from equipment cleaning.

    Each owner or operator of a new or existing slabstock affected 
source shall not use HAP or a HAP-based material as an equipment 
cleaner.

Sec.  63.1299  [Removed and Reserved]

0
11. Remove and reserve Sec.  63.1299.
0
12. Revise Sec.  63.1302 to read as follows:

Sec.  63.1302  Applicability of subpart A requirements.

    The owner or operator of an affected source shall comply with the 
applicable requirements of subpart A of this part, as specified in 
Table 1 of this subpart.
0
13. Section 63.1303 is amended by:
0
a. Revising paragraph (a) introductory text;
0
b. Removing paragraphs (a)(3) and (a)(4);
0
c. Revising paragraph (b); and
0
d. Removing paragraphs (c), (d) and (e).
    The revisions read as follows:

Sec.  63.1303  Monitoring requirements.

* * * * *
    (a) Monitoring requirements for storage vessel carbon adsorption 
systems. Each owner or operator using a carbon adsorption system to 
meet the requirements of Sec.  63.1294(a) shall monitor the 
concentration level of the HAP or the organic compounds in the exhaust 
vent stream (or outlet stream exhaust) from the carbon adsorption 
system at the frequency specified in paragraphs (a)(1) or (2) of this 
section.
* * * * *
    (b) Each owner or operator using a carbon adsorption system to meet 
the requirements of Sec.  63.1294(a) shall monitor the concentration 
level of total organic compounds in the exhaust vent stream (or outlet 
stream exhaust) from the carbon adsorption system using 40 CFR part 60, 
Appendix A, Method 25A, reported as propane. The measurement shall be 
conducted over at least one 5-minute interval during which the storage 
vessel is being filled.

Sec.  63.1304  [Removed and Reserved]

0
14. Remove and reserve Sec.  63.1304.
0
15. Section 63.1306 is amended by:
0
a. Removing paragraph (c);
0
b. Redesigating paragraphs (d) and (e) as paragraphs (c) and (d);
0
c. Revising newly redesignated paragraphs (c) introductory text and 
(c)(3);
0
d. Revising newly redesignated paragraph (d);
0
e. Revising paragraph (f);
0
f. Redesignating paragraph (g) as paragraph (e);
0
g. Revising newly redesignated paragraphs (e)(1) and (2); and
0
h. Adding a new paragraph (g).
    The addition and revisions read as follows:

Sec.  63.1306  Reporting requirements.

* * * * *
    (c) Notification of compliance status. Each affected source shall 
submit a notification of compliance status report no later than 180 
days after the compliance date. For slabstock affected sources, this 
report shall contain the information listed in paragraphs (c)(1) 
through (3) of this section, as applicable. This report shall contain 
the information listed in paragraph (c)(4) of this section for molded 
foam processes and in paragraph (c)(5) of this section for rebond foam 
processes.
* * * * *
    (3) A statement that the slabstock foam affected source is in 
compliance with Sec. Sec.  63.1297 and 63.1298, or a statement that 
slabstock foam processes at an affected source are in compliance with 
Sec. Sec.  63.1297 and 63.1298.
* * * * *
    (d) Semiannual reports. Each slabstock affected source shall submit 
a report containing the information specified in paragraphs (d)(1) 
through (3) of this section semiannually no later than 60 days after 
the end of each 180 day period. The first report shall be submitted no 
later than 240 days after the date that the Notification of Compliance 
Status is due and shall cover the 6-month period beginning on the date 
that the Notification of Compliance Status Report is due.
    (1) For sources complying with the storage vessel provisions of 
Sec.  63.1294(a) using a carbon adsorption system, unloading events 
that occurred after breakthrough was detected and before the carbon was 
replaced.
    (2) Any equipment leaks that were not repaired in accordance with 
Sec. Sec.  63.1294(b)(2)(iii) and 63.1294(c).
    (3) Any leaks in vapor return lines that were not repaired in 
accordance with Sec.  63.1294(a)(1)(ii).
    (e) * * *
    (1) The compliance certification shall be based on information 
consistent with that contained in Sec.  63.1308, as applicable.
    (2) A compliance certification required pursuant to a state or 
local operating permit program may be used to satisfy the requirements 
of this section, provided that the compliance certification is based on 
information consistent with that contained in Sec.  63.1308, and 
provided that the Administrator has approved the state or local 
operating permit program under part 70 of this chapter.
* * * * *
    (f) Malfunction reports. If a source fails to meet an applicable 
standard, slabstock affected sources must report such events in the 
next semiannual report and molded and rebond affected sources must 
report such events in the next annual compliance certification. Report 
the number of failures to meet an applicable standard. For each 
instance, report the date, time and duration of each failure. For each 
failure, the report must include a list of the affected sources or 
equipment, an estimate of the volume of each regulated pollutant 
emitted over any emission limit, and a

[[Page 66136]]

description of the method used to estimate the emissions.
    (g) Within 60 days after the date of completing each performance 
test (as defined in Sec.  63.2), you must submit the results of the 
performance tests required by this subpart according to the methods 
specified in paragraphs (g)(1) or (g)(2) of this section.
    (1) For data collected using test methods supported by the EPA-
provided software, the owner or operator shall submit the results of 
the performance test to the EPA by direct computer-to-computer 
electronic transfer via EPA-provided software, unless otherwise 
approved by the Administrator. Owners or operators, who claim that some 
of the information being submitted for performance tests is 
confidential business information (CBI), must submit a complete file 
using EPA-provided software that includes information claimed to be CBI 
on a compact disk, flash drive, or other commonly used electronic 
storage media to the EPA. The electronic media must be clearly marked 
as CBI and mailed to U.S. EPA/OAQPS/CORE CBI Office, Attention: WebFIRE 
Administrator, MD C404-02, 4930 Old Page Rd., Durham, NC 27703. The 
same file with the CBI omitted must be submitted to the EPA by direct 
computer-to-computer electronic transfer via EPA-provided software.
    (2) For any performance test conducted using test methods that are 
not compatible with the EPA-provided software, the owner or operator 
shall submit the results of the performance test to the Administrator 
at the appropriate address listed in Sec.  63.13.
0
16. Section 63.1307 is amended by:
0
a. Removing paragraph (a)(2) and redesignating paragraphs (a)(3) and 
(a)(4) as paragraphs (a)(2) and (a)(3);
0
b. Revising the newly redesignated paragraphs (a)(2) introductory text, 
(a)(2)(ii), and (a)(3) introductory text;
0
c. Revising paragraph (b)(1);
0
d. Revising paragraphs (b)(3) introductory text, (b)(3)(i) introductory 
text and (b)(3)(i)(B);
0
e. Removing paragraph (b)(3)(i)(C);
0
f. Revising paragraphs (b)(3)(ii) introductory text and (b)(3)(ii)(A);
0
g. Removing paragraph (b)(3)(ii)(D);
0
h. Redesignating paragraphs (b)(3)(ii)(E) through (b)(3)(ii)(H) as 
(b)(3)(ii)(D) through (b)(3)(ii)(G);
0
i. Revising paragraph (c);
0
j. Removing paragraph (d);
0
k. Redesignating paragraphs (e) through (h) as (d) through (g);
0
l. Revising newly redesignated paragraph (e); and
0
m. Adding paragraph (h).
    The additions and revisions read as follows:

Sec.  63.1307  Recordkeeping requirements.

* * * * *
    (a) * * *
    (2) For storage vessels complying through the use of a carbon 
adsorption system, paragraphs (a)(2)(i) or (ii), and paragraph 
(a)(2)(iii) of this section.
* * * * *
    (ii) For affected sources monitoring at an interval no greater than 
20 percent of the carbon replacement interval, in accordance with Sec.  
63.1303(a)(2), the records listed in paragraphs (a)(2)(ii)(A) and (B) 
of this section.
* * * * *
    (3) For storage vessels complying through the use of a vapor return 
line, paragraphs (a)(3)(i) through (iii) of this section.
* * * * *
    (b) * * * (1) A list of components in diisocyanate service.
* * * * *
    (3) When a leak is detected as specified in Sec. Sec.  
63.1294(b)(2)(ii) and 63.1294(c), the requirements listed in paragraphs 
(b)(3)(i) and (ii) of this section apply:
    (i) Leaking equipment shall be identified in accordance with the 
requirements in paragraphs (b)(3)(i)(A) and (B) of this section.
* * * * *
    (B) The identification on equipment may be removed after it has 
been repaired.
    (ii) The information in paragraphs (b)(2)(ii)(A) through (G) shall 
be recorded for leaking components.
    (A) The operator identification number and the equipment 
identification number.
* * * * *
    (c) The owner or operator of an affected source subject to Sec.  
63.1297 shall maintain a product data sheet for each ABA used which 
includes the HAP content, in kg of HAP/kg solids (lb HAP/lb solids).
* * * * *
    (e) The owner or operator of an affected source following the 
compliance methods in Sec.  63.1308(b)(1) shall maintain records of 
each use of a vapor return line during unloading, of any leaks detected 
during unloading, and of repairs of leaks detected during unloading.
* * * * *
    (h) Malfunction records. Records shall be kept as specified in 
paragraphs (h)(1) through (3) of this section for affected sources. 
Records are not required for emission points that do not require 
control under this subpart.
    (1) In the event that an affected unit fails to meet an applicable 
standard, record the number of failures. For each failure, record the 
date, time and duration of the failure.
    (2) For each failure to meet an applicable standard, record and 
retain a list of the affected sources or equipment, an estimate of the 
volume of each regulated pollutant emitted over any emission limit and 
a description of the method used to estimate the emissions.
    (3) Record actions taken to minimize emissions in accordance with 
Sec.  63.1290(d) and any corrective actions taken to return the 
affected unit to its normal or usual manner of operation.
0
17. Section 63.1308 is amended by:
0
a. Revising paragraph (a) introductory text;
0
b. Revising paragraphs (b)(3), (b)(6), and (c);
0
c. Removing paragraph (d); and
0
d. Redesignating paragraph (e) as (d).
    The revisions read as follows:

Sec.  63.1308  Compliance demonstrations.

    (a) For each affected source, compliance with the requirements 
described in Tables 2 and 3 of this subpart shall mean compliance with 
the requirements contained in Sec. Sec.  63.1293 through 63.1301, 
absent any credible evidence to the contrary.
* * * * *
    (b) * * *
    (3) For each affected source complying with Sec.  63.1294(a) in 
accordance with Sec.  63.1294(a)(2) through the alternative monitoring 
procedures in Sec.  63.1303(a)(2), each unloading event that the 
diisocyanate storage vessel is not equipped with a carbon adsorption 
system, each time that the carbon adsorption system is not monitored 
for breakthrough in accordance with Sec.  63.1303(b)(1) or (2) at the 
interval established in the design analysis, and each unloading event 
that occurs when the carbon is not replaced after an indication of 
breakthrough;
* * * * *
    (6) For each affected source complying with Sec.  63.1294(c), each 
calendar day after 5 calendar days after detection of a leak that a 
first attempt at repair has not been made, and the earlier of each 
calendar day after 15 calendar days after detection of a leak that a 
leak is not repaired, or if a leak is not repaired as soon as 
practicable, each subsequent calendar day (with the exception of 
situations meeting the criteria of Sec.  63.1294(d)).
    (c) Slabstock affected sources. For slabstock foam affected 
sources, failure to meet the requirements contained in Sec. Sec.  
63.1297 and 63.1298, respectively, shall be considered a violation of 
this subpart. Violation of each item listed in

[[Page 66137]]

the following paragraphs shall be considered a separate violation.
    (1) For each slabstock foam affected source subject to the 
provisions in Sec.  63.1297, each calendar day that a HAP ABA or HAP-
based material is used as an ABA;
    (2) For each slabstock foam affected source subject to the 
provisions of Sec.  63.1298, each calendar day that a HAP-based 
material is used as an equipment cleaner.
* * * * *
0
18. Section 63.1309 is amended by removing paragraph (b)(4) and 
redesignating paragraph (b)(5) as (b)(4).
0
19. Remove Table 1 to Subpart III of part 63.
0
20. Redesignate Table 2 to Subpart III of Part 63 as Table 1 to Subpart 
III of Part 63 and amend newly redesignated Table 1 by:
0
a. Revising the heading of newly redesignated Table 1;
0
b. Removing entry Sec.  63.6(e)(1)-(2);
0
c. Adding entries Sec.  63.6(e)(1)(i), Sec.  63.6(e)(1)(ii) and Sec.  
63.6(e)(1)(iii);
0
d. Removing entry Sec.  63.6(e)(3);
0
e. Adding entry Sec.  63.6(e)(2)-(3):
0
f. Removing entry Sec.  63.6(f)-(g);
0
g. Adding entries Sec.  63.6(f)(1), Sec.  63.6(f)(2)-(3), and Sec.  
63.6(g);
0
h. Removing entry Sec.  63.10(a)-(b);
0
i. Adding entries Sec.  63.10(a), Sec.  63.10(b)(1), Sec.  
63.10(b)(2)(i), Sec.  63.10(b)(2)(ii); Sec.  63.10(b)(2)(iii); Sec.  
63.10(b)(2)(iv)-(xi); Sec.  63.10(b)(2)(xii); Sec.  63.10(b)(2)(xiii), 
Sec.  63.10(b)(2)(xiv); and Sec.  63.10(b)(3);
0
j. Removing entry Sec.  63.10(d)(4)-(5); and
0
k. Adding entries Sec.  63.10(d)(4) and Sec.  63.10(d)(5).
    The additions and revisions read as follows:

 Table 1 to Subpart III of Part 63--Applicability of General Provisions
               (40 CFR Part 63, Subpart A) to Subpart III
------------------------------------------------------------------------
                               Applies to  subpart
     Subpart A reference               III                 Comment
------------------------------------------------------------------------
 
                              * * * * * * *
Sec.   63.6(e)(1)(i)........  NO..................  See Sec.
                                                     63.1290(d)(4) for
                                                     general duty
                                                     requirement.
Sec.   63.6(e)(1)(ii).......  NO.
Sec.   63.6(e)(1)(iii)......  YES.
Sec.   63.6(e)(2)-(3).......  NO.
Sec.   63.6(f)(1)...........  NO.
Sec.   63.6(f)(2)-(3).......  YES.
Sec.   63.6(g)..............  YES.
 
                              * * * * * * *
Sec.   63.10(a).............  YES.
Sec.   63.10(b)(1)..........  YES.
Sec.   63.10(b)(2)(i).......  NO.
Sec.   63.10(b)(2)(ii)......  NO..................  See Sec.
                                                     63.1307(h) for
                                                     recordkeeping of
                                                     (1) date, time and
                                                     duration; (2)
                                                     listing of affected
                                                     source or equipment
                                                     and an estimate of
                                                     the volume of each
                                                     regulated pollutant
                                                     emitted over the
                                                     standard; and (3)
                                                     actions to minimize
                                                     emissions and any
                                                     actions taken at
                                                     the discretion of
                                                     the owner or
                                                     operator to prevent
                                                     recurrence of the
                                                     failure to meet an
                                                     applicable
                                                     requirement.
Sec.   63.10(b)(2)(iii).....  YES.
Sec.   63.10(b)(2)(iv)-(xi).  NO.
Sec.   63.10(b)(2)(xii).....  YES.
Sec.   63.10(b)(2)(xiii)....  NO.
Sec.   63.10(b)(2)(xiv).....  YES.
Sec.   63.10(b)(3)..........  YES.
 
                              * * * * * * *
Sec.   63.10(d)(4)..........  YES.
Sec.   63.10(d)(5)..........  NO..................  See Sec.
                                                     63.1306(f) for
                                                     malfunction
                                                     reporting
                                                     requirements.
 
                              * * * * * * *
------------------------------------------------------------------------

0
21. Redesignate Table 3 to Subpart III of Part 63 as Table 2 to Subpart 
III of Part 63 and amend newly redesignated Table 2 by:
0
a. Revising the heading for newly redesignated Table 2;
0
b. Removing entries for HAP ABA storage vessels Sec.  63.1295, HAP ABA 
pumps Sec.  63.1296(a), HAP ABA valves Sec.  63.1296(b), HAP ABA 
connectors Sec.  63.1296(c), Pressure relief devices Sec.  63.1296(d), 
Open-ended valves or lines Sec.  63.1296(e), and Production line Sec.  
63.1297; and
0
c. Adding an entry for ABAs Sec.  63.1297.
    The revisions and addition read as follows:

[[Page 66138]]

    Table 2 to Subpart III of Part 63--Compliance Requirements for Slabstock Foam Production Affected Sources
----------------------------------------------------------------------------------------------------------------
                                                  Emission, work
                                  Emission point   practice, and
         Emission point             compliance       equipment      Monitoring     Recordkeeping     Reporting
                                      option         standards
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
ABAs Sec.   63.1297.............             N/A  Sec.   63.1297  ..............            Sec.  ..............
                                                                                      63.1307(e)
----------------------------------------------------------------------------------------------------------------

0
22. Remove Table 4 to Subpart III of Part 63.
0
23. Redesignate Table 5 to Subpart III of Part 63 as Table 3 to Subpart 
III of Part 63 and amend newly redesignated Table 3 by revising the 
heading to read as follows:
    Table 3 to Subpart III of Part 63--Compliance Requirements for 
Molded and Rebond Foam Production Affected Sources
* * * * *
[FR Doc. 2013-24276 Filed 11-1-13; 8:45 am]
BILLING CODE 6560-50-P
```