[Federal Register Volume 86, Number 6 (Monday, January 11, 2021)]
[Proposed Rules]
[Pages 1868-1890]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-00250]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2020-0572; FRL-10017-90-OAR]
RIN 2060-AU57


National Emission Standards for Hazardous Air Pollutants: 
Flexible Polyurethane Foam Fabrication Operations Residual Risk and 
Technology Review and Flexible Polyurethane Foam Production and 
Fabrication Area Source Technology Review

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: This action presents the proposed results of the U.S. 
Environmental Protection Agency's (EPA's) residual risk and technology 
review (RTR) required under the Clean Air Act (CAA) for the National 
Emission Standards for Hazardous Air Pollutants (NESHAP) for major 
source Flexible Polyurethane Foam Fabrication Operations, initially 
promulgated in 2003. Pursuant to the CAA, this action also presents the 
proposed results of the technology review for the NESHAP for two area 
source categories, Flexible Polyurethane Foam Production and Flexible 
Polyurethane Foam Fabrication, which are combined in one subpart 
initially promulgated in 2007. In this action, the EPA is proposing to 
establish a numeric emission limit for one major source subcategory; 
remove exemptions for periods of startup, shutdown, and malfunction 
(SSM) and specify that the emissions standards apply at all times; 
require periodic performance tests; and require electronic reporting of 
performance test results and compliance reports. Implementation of 
these proposed rules is not expected to result in significant changes 
to the hazardous air pollutant (HAP) emissions from affected facilities 
in these three source categories or to human health impacts or 
environmental impacts associated with those emissions. However, this 
action, if finalized, would result in improved monitoring, compliance, 
and implementation of the existing standards and codify existing 
industry practices to prevent backsliding.

DATES: Comments. Comments must be received on or before February 25, 
2021. Under the Paperwork Reduction Act (PRA), comments on the 
information collection provisions are best assured of consideration if 
the Office of Management and Budget (OMB) receives a copy of your 
comments on or before February 10, 2021.
    Public hearing: If anyone contacts us requesting a public hearing 
on or before January 19, 2021, we will hold a virtual public hearing. 
See SUPPLEMENTARY INFORMATION for information on requesting and 
registering for a public hearing.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OAR-2020-0572 by any of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov/ 
(our preferred method). Follow the online instructions for submitting 
comments.
     Email: [email protected]. Include Docket ID No. EPA-
HQ-OAR-2020-0572- in the subject line of the message.
     Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2020-0572.
     Mail: U.S. Environmental Protection Agency, EPA Docket 
Center, Docket ID No. EPA-HQ-OAR-2020-0572 EPA Mail Code 28221T, 1200 
Pennsylvania Avenue NW, Washington, DC 20460.
     Hand/Courier Delivery: EPA Docket Center, WJC West 
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004. 
The Docket Center's hours of operation are 8:30 a.m.-4:30 p.m., Monday-
Friday (except federal holidays).
    Instructions: All submissions received must include the Docket ID 
No. for this rulemaking. Comments received may be posted without change 
to https://www.regulations.gov/, including any personal information 
provided. For detailed instructions on sending comments and additional 
information on the rulemaking process, see the SUPPLEMENTARY 
INFORMATION section of this document. Out of an abundance of caution 
for members of the public and our staff, the EPA Docket Center and 
Reading Room are closed to the public, with limited exceptions, to 
reduce the risk of transmitting COVID-19. Our Docket Center staff will 
continue to provide remote customer service via email, phone, and 
webform. We encourage the public to submit comments via https://www.regulations.gov/ or email, as there may be a delay in processing 
mail and faxes. Hand deliveries and couriers may be received by 
scheduled appointment only. For further information on EPA Docket 
Center services and the current status, please visit us online at 
https://www.epa.gov/dockets.

[[Page 1869]]


FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Dr. Tina Ndoh, Sector Policies and Programs Division 
(D243-04), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711; telephone number: (919) 541-1516; fax number: (919) 541-4991; 
and email address: [email protected]. For specific information 
regarding the risk modeling 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: 
[email protected].

SUPPLEMENTARY INFORMATION: 
    Participation in virtual public hearing. Please note that the EPA 
is deviating from its typical approach for public hearings because the 
President has declared a national emergency. Due to the current Centers 
for Disease Control and Prevention (CDC) recommendations, as well as 
state and local orders for social distancing to limit the spread of 
COVID-19, the EPA cannot hold in-person public meetings at this time.
    To request a virtual public hearing, contact the public hearing 
team at (888) 372-8699 or by email at [email protected]. If 
requested, the virtual hearing will be held on January 26, 2021. The 
hearing will convene at 9:00 a.m. Eastern Time (ET) and will conclude 
at 3:00 p.m. ET. The EPA may close a session 15 minutes after the last 
pre-registered speaker has testified if there are no additional 
speakers. The EPA will announce further details at https://www.epa.gov/stationary-sources-air-pollution/flexible-polyurethane-foam-fabrication-operations-national-emission.
    Upon publication of this document in the Federal Register, the EPA 
will begin pre-registering speakers for the hearing, if a hearing is 
requested. To register to speak at the virtual hearing, please use the 
online registration form available at https://www.epa.gov/stationary-sources-air-pollution/flexible-polyurethane-foam-fabrication-operations-national-emission or contact the public hearing team at 
(888) 372-8699 or by email at [email protected]. The last day 
to pre-register to speak at the hearing will be January 25, 2021. Prior 
to the hearing, the EPA will post a general agenda that will list pre-
registered speakers in approximate order at: https://www.epa.gov/stationary-sources-air-pollution/flexible-polyurethane-foam-fabrication-operations-national-emission.
    The EPA will make every effort to follow the schedule as closely as 
possible on the day of the hearing; however, please plan for the 
hearings to run either ahead of schedule or behind schedule.
    Each commenter will have 5 minutes to provide oral testimony. The 
EPA encourages commenters to provide the EPA with a copy of their oral 
testimony electronically (via email) by emailing it to 
[email protected]. The EPA also recommends submitting the text of your 
oral testimony as written comments to the rulemaking docket.
    The EPA may ask clarifying questions during the oral presentations 
but will not respond to the presentations at that time. Written 
statements and supporting information submitted during the comment 
period will be considered with the same weight as oral testimony and 
supporting information presented at the public hearing.
    Please note that any updates made to any aspect of the hearing will 
be posted online at https://www.epa.gov/stationary-sources-air-pollution/flexible-polyurethane-foam-fabrication-operations-national-emission. While the EPA expects the hearing to go forward as set forth 
above, please monitor our website or contact the public hearing team at 
(888) 372-8699 or by email at [email protected] to determine if 
there are any updates. The EPA does not intend to publish a document in 
the Federal Register announcing updates.
    If you require the services of a translator or a special 
accommodation such as audio description, please pre-register for the 
hearing with the public hearing team and describe your needs by January 
19, 2021. The EPA may not be able to arrange accommodations without 
advanced notice.
    Docket. The EPA has established a docket for this rulemaking under 
Docket ID No. EPA-HQ-OAR-2020-0572. All documents in the docket are 
listed in https://www.regulations.gov/. Although listed, some 
information is not publicly available, e.g., Confidential Business 
Information (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. With the exception of such material, publicly available docket 
materials are available electronically in Regulations.gov.
    Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2020-0572. 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 https://www.regulations.gov/, including any personal 
information provided, unless the comment includes information claimed 
to be CBI or other information whose disclosure is restricted by 
statute. Do not submit electronically any information that you consider 
to be CBI or other information whose disclosure is restricted by 
statute. This type of information should be submitted by mail as 
discussed below.
    The EPA may publish any comment received to its public docket. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. The EPA 
will generally not consider comments or comment contents located 
outside of the primary submission (i.e., on the Web, cloud, or other 
file sharing system). For additional submission methods, the full EPA 
public comment policy, information about CBI or multimedia submissions, 
and general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.
    The https://www.regulations.gov/ website allows you to submit your 
comment anonymously, 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 
https://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 
digital storage media 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 https://www.epa.gov/dockets.
    The EPA is temporarily suspending its Docket Center and Reading 
Room for public visitors, with limited exceptions, to reduce the risk 
of transmitting COVID-19. Our Docket Center staff will continue to 
provide remote customer service via email, phone, and webform.

[[Page 1870]]

We encourage the public to submit comments via https://www.regulations.gov/ as there may be a delay in processing mail and 
faxes. Hand deliveries or couriers will be received by scheduled 
appointment only. For further information and updates on EPA Docket 
Center services, please visit us online at https://www.epa.gov/dockets.
    The EPA continues to carefully and continuously monitor information 
from the CDC, local area health departments, and our Federal partners 
so that we can respond rapidly as conditions change regarding COVID-19.
    Submitting CBI. Do not submit information containing CBI to the EPA 
through https://www.regulations.gov/ or email. Clearly mark the part or 
all of the information that you claim to be CBI. For CBI information on 
any digital storage media that you mail to the EPA, mark the outside of 
the digital storage media as CBI and then identify electronically 
within the digital storage media 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 directly 
to the public docket through the procedures outlined in Instructions 
above. If you submit any digital storage media that does not contain 
CBI, mark the outside of the digital storage media 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: OAQPS Document Control Officer (C404-02), OAQPS, 
U.S. Environmental Protection Agency, Research Triangle Park, North 
Carolina 27711, Attention Docket ID No. EPA-HQ-OAR-2020-0572. Note that 
written comments containing CBI and submitted by mail may be delayed 
and no hand deliveries will be accepted.
    Preamble acronyms and abbreviations. We use multiple acronyms and 
terms in this preamble. 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:

AEGL acute exposure guideline level
AERMOD air dispersion model used by the HEM-3 model
ATSDR Agency for Toxic Substances and Disease Registry
CAA Clean Air Act
CalEPA California EPA
CBI Confidential Business Information
CDC Centers for Disease Control and Prevention
CDX Central Data Exchange
CEDRI Compliance and Emissions Data Reporting
CFR Code of Federal Regulations
EPA Environmental Protection Agency
ERPG emergency response planning guideline
ERT Electronic Reporting Tool
GACT generally available control technology
HAP hazardous air pollutant(s)
HCl hydrochloric acid
HEM-3 Human Exposure Model, Version 1.5.5
HF hydrogen fluoride
HI hazard index
HQ hazard quotient
IRIS Integrated Risk Information System
km kilometer
MACT maximum achievable control technology
mg/m\3\ milligrams per cubic meter
MIR maximum individual risk
NAICS North American Industry Classification System
NATA National Air Toxics Assessment
NEI National Emissions Inventory
NESHAP national emission standards for hazardous air pollutants
NSR New Source Review
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
PDF portable document format
POM polycyclic organic matter
ppm parts per million
RBLC Reasonably Available Control Technology, Best Available Control 
Technology, and Lowest Achievable Emission Rate Clearinghouse
REL reference exposure level
RfC reference concentration
RfD reference dose
RTR residual risk and technology review
SAB Science Advisory Board
SDS safety data sheets
SSM startup, shutdown, and malfunction
TDI toluene diisocyanate
TOSHI target organ-specific hazard index
tpy tons per year
TRI Toxics Release Inventory
TRIM.FaTE Total Risk Integrated Methodology.Fate, Transport, and 
Ecological Exposure model
UF uncertainty factor
URE unit risk estimate

    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?
II. Background
    A. What is the statutory authority for this action?
    B. What are the source categories and how do the current NESHAP 
regulate their HAP emissions?
    C. What data collection activities were conducted to support 
this action?
    D. What other relevant background information and data are 
available?
III. Analytical Procedures and Decision-Making
    A. How do we consider risk in our decision-making?
    B. How do we perform the technology review?
    C. How do we estimate post-MACT risk posed by the source 
category?
IV. Analytical Results and Proposed Decisions
    A. What actions are we taking pursuant to CAA sections 112(d)(2) 
and 112(d)(3) for the Flexible Polyurethane Foam Fabrication 
Operations source category?
    B. What are the results of the risk assessment and analyses for 
the Flexible Polyurethane Foam Fabrication Operations source 
category?
    C. What are our proposed decisions regarding risk acceptability, 
ample margin of safety, and adverse environmental effect?
    D. What are the results and proposed decisions based on our 
technology review for the Flexible Polyurethane Foam Fabrication 
Operations major source category and for the Flexible Polyurethane 
Foam Production and Fabrication area source categories?
    E. What other actions are we proposing?
    F. 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. Executive Order 13771: Reducing Regulations and Controlling 
Regulatory Costs
    C. Paperwork Reduction Act (PRA)
    D. Regulatory Flexibility Act (RFA)
    E. Unfunded Mandates Reform Act (UMRA)
    F. Executive Order 13132: Federalism
    G. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    H. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    I. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    J. National Technology Transfer and Advancement Act (NTTAA)
    K. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

[[Page 1871]]

I. General Information

A. Does this action apply to me?

    The source categories that are the subject of this proposal are 
Flexible Polyurethane Foam Fabrication Operations Major Sources 
regulated under 40 CFR part 63, subpart MMMMM, and Flexible 
Polyurethane Foam Production and Flexible Polyurethane Foam Fabrication 
Area Sources, regulated under 40 CFR part 63, subpart OOOOOO. The North 
American Industry Classification System (NAICS) code for fabricators of 
flexible polyurethane foam industry is 326150. This list of categories 
and NAICS codes is not intended to be exhaustive, but rather provides a 
guide for readers regarding the entities that this proposed action is 
likely to affect. The proposed standards, once promulgated, will be 
directly applicable to the affected sources. Federal, state, local, and 
tribal government entities would not be affected by this proposed 
action.
    The Flexible Polyurethane Foam Fabrication Operations major source 
category was added to the EPA's HAP source category list in 1996. (61 
FR 28197, June 4, 1996.) The NESHAP for that major source category, 40 
CFR part 63, subpart MMMMM, was promulgated in 2003. (68 FR 18062, 
April 14, 2003.) The Flexible Polyurethane Foam Fabrication area source 
category was added to the EPA's HAP source category list in 1999. (64 
FR 38706, July 19, 1999.) The Flexible Polyurethane Foam Production 
area source category was added to the EPA's HAP source category list in 
2002. (67 FR 70427, November 22, 2002.) The Flexible Polyurethane Foam 
Production major source category, Part 63, subpart III, was included on 
the EPA's initial HAP source category list. (57 FR 31576, July 16, 
1992.) The maximum achievable control technology (MACT) standards for 
subpart III were initially promulgated in 1998. (63 FR 53980, October 
7, 1998.) The EPA established one area source NESHAP at 40 CFR part 63, 
subpart OOOOOO, that applies to the two area source categories due to 
similarity of their operations and because they are often collocated. 
(72 FR 38864, July 16, 2007.)
    The Flexible Polyurethane Foam Fabrication Operations major source 
category and the Flexible Polyurethane Foam Fabrication area source 
category include facilities engaged in cutting, gluing, and/or 
laminating pieces of flexible polyurethane foam. Those source 
categories include fabrication operations that are collocated with foam 
production plants as well as those located offsite from foam production 
plants. Emissions from foam fabrication primarily result from the 
lamination of polyurethane foam to adhere foam to other substrates and 
from the use of HAP-based adhesives in the gluing process. The Flexible 
Polyurethane Foam Production area source category includes facilities 
that manufacture foam made from a polymer containing a plurality of 
carbamate linkages in the chain backbone (polyurethane). Polyurethane 
is commonly made by reacting a polyisocyanate with an organic 
polyhydroxyl material in the presence of water. Application of blowing 
agents, catalysts, surfactants, and fillers transform the polyurethane 
into a foam with specialized properties.
    This proposed action addresses the major source NESHAP that applies 
to the Flexible Polyurethane Foam Fabrication Operations major source 
category and also addresses the area source NESHAP that applies to the 
Flexible Polyurethane Foam Production area source category and the 
Flexible Polyurethane Foam Fabrication area source category.

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. Following signature by the 
EPA Administrator, the EPA will post a copy of this proposed action at 
https://www.epa.gov/stationary-sources-air-pollution/flexible-polyurethane-foam-fabrication-operations-national-emission. Following 
publication in the Federal Register, the EPA will post the Federal 
Register version of the proposal and key technical documents at this 
same website. Information on the overall RTR program is available at 
https://www3.epa.gov/ttn/atw/rrisk/rtrpg.html.
    The proposed changes to the CFR that would be necessary to 
incorporate the changes proposed in this action are set out in an 
attachment to the memorandum titled Proposed Regulation Edits for 40 
CFR Part 63, subparts MMMMM and OOOOOO, available in the docket for 
this action (Docket ID No. EPA-HQ-OAR-2020-0572). This document 
includes the specific proposed amendatory language for revising the CFR 
and, for the convenience of interested parties, a redline version of 
the regulations. Following signature by the EPA Administrator, the EPA 
will also post a copy of this memorandum and the attachment to https://www.epa.gov/stationary-sources-air-pollution/flexible-polyurethane-foam-fabrication-operations-national-emission.

II. Background

A. What is the statutory authority for this action?

    The statutory authority for this action is provided by sections 112 
and 301 of the CAA, as amended (42 U.S.C. 7401 et seq.). Section 112 of 
the CAA establishes a two-stage regulatory process to develop standards 
for emissions of HAP from stationary sources. Generally, the first 
stage involves establishing technology-based standards and the second 
stage involves evaluating those standards that are based on MACT to 
determine whether additional standards are needed to address any 
remaining risk associated with HAP emissions. This second stage is 
commonly referred to as the ``residual risk review.'' In addition to 
the residual risk review, the CAA also requires the EPA to review 
standards set under CAA section 112 every 8 years and revise the 
standards as necessary taking into account any ``developments in 
practices, processes, or control technologies.'' This review is 
commonly referred to as the ``technology review.'' When the two reviews 
are combined into a single rulemaking, it is commonly referred to as 
the ``risk and technology review.'' The discussion that follows 
identifies the most relevant statutory sections and briefly explains 
the contours of the methodology used to implement these statutory 
requirements. A more comprehensive discussion appears in the document 
titled CAA Section 112 Risk and Technology Reviews: Statutory Authority 
and Methodology, in the docket for this proposed rule (Docket ID No. 
EPA-HQ-OAR-2020-0572).
    In the first stage of the CAA section 112 standard setting process, 
the EPA promulgates technology-based standards under CAA section 112(d) 
for categories of sources identified as emitting one or more of the HAP 
listed in CAA section 112(b). Sources of HAP emissions are either major 
sources or area sources, and CAA section 112 establishes different 
requirements for major source standards and area source standards. 
``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. All other sources are ``area sources.'' For major 
sources, CAA section 112(d)(2) provides that the technology-based 
NESHAP must reflect the maximum degree of emission reductions of HAP 
achievable (after considering cost, energy requirements, and non-air

[[Page 1872]]

quality health and environmental impacts). These standards are commonly 
referred to as MACT standards. CAA section 112(d)(3) also establishes a 
minimum control level for MACT standards, known as the MACT ``floor.'' 
In certain instances, as provided in CAA section 112(h), the EPA may 
set work practice standards in lieu of numerical emission standards. 
The EPA must also consider control options that are more stringent than 
the floor. Standards more stringent than the floor are commonly 
referred to as beyond-the-floor standards. For area sources, CAA 
section 112(d)(5) gives the EPA discretion to set standards based on 
generally available control technologies or management practices (GACT 
standards) in lieu of MACT standards.
    The second stage in standard-setting focuses on identifying and 
addressing any remaining (i.e., ``residual'') risk pursuant to CAA 
section 112(f). For source categories subject to MACT standards, 
section 112(f)(2) of the CAA requires the EPA to determine whether 
promulgation of additional standards is needed to provide an ample 
margin of safety to protect public health or to prevent an adverse 
environmental effect. Section 112(d)(5) of the CAA provides that this 
residual risk review is not required for categories of area sources 
subject to GACT standards. Section 112(f)(2)(B) of the CAA further 
expressly preserves the EPA's use of the two-step approach 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 Residual 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 the United States Court of Appeals for the District of Columbia 
Circuit (the court) upheld the EPA's interpretation that CAA section 
112(f)(2) incorporates the approach established in the Benzene NESHAP. 
See NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 2008).
    The approach incorporated into the CAA and used by the EPA to 
evaluate residual risk and to develop standards under CAA section 
112(f)(2) is a two-step approach. 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) 
\1\ of approximately 1 in 10 thousand.'' (54 FR at 38045). If risks are 
unacceptable, the EPA must determine the emissions standards necessary 
to reduce risk to an acceptable level without considering costs. In the 
second step of the approach, the EPA considers whether the emissions 
standards provide an ample margin of safety to protect public health 
``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 emission standards 
necessary to provide an ample margin of safety to protect public health 
or determine that the standards being reviewed provide an ample margin 
of safety without any revisions. 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.
---------------------------------------------------------------------------

    \1\ Although defined as ``maximum individual risk,'' MIR refers 
only to cancer risk. MIR, one metric for assessing cancer risk, is 
the estimated risk if an individual were exposed to the maximum 
level of a pollutant for a lifetime.
---------------------------------------------------------------------------

    CAA section 112(d)(6) separately requires the EPA to review 
standards promulgated under CAA section 112 and revise them ``as 
necessary (taking into account developments in practices, processes, 
and control technologies)'' no less often than every 8 years. In 
conducting this review, which we call the ``technology 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 EPA may consider cost in deciding whether to revise the 
standards pursuant to CAA section 112(d)(6). The EPA is required to 
address regulatory gaps, such as missing standards for listed air 
toxics known to be emitted from the source category. Louisiana 
Environmental Action Network (LEAN) v. EPA, 955 F.3d 1088 (D.C. Cir. 
2020). Section 112(k)(3)(B) of the CAA required the EPA to identify at 
least 30 HAP that pose the greatest potential health threat in urban 
areas, and CAA section 112(c)(3) requires the EPA to regulate the area 
source categories that represent 90 percent of the emissions of the 30 
``listed'' HAP (``urban HAP'').

B. What are the source categories and how do the current NESHAP 
regulate their HAP emissions?

    For both the Flexible Polyurethane Foam Fabrication Operations 
major source category and the Flexible Polyurethane Foam Fabrication 
area source category, operations involve cutting, bonding, and/or 
laminating pieces of flexible polyurethane foam together or to other 
substrates. Typical bonding techniques include gluing, taping, and 
flame lamination. In years preceding the listing of the flexible 
polyurethane foam fabrication major and area source categories, some 
foam fabrication operations may have used methylene chloride-based 
adhesives to adhere pieces of foam together; however, the industry no 
longer uses any methylene chloride-based adhesives. Most foam 
fabrication adhesives are applied by workers using spray guns. 
Application of adhesives is typically performed in large open rooms, 
with workstations spaced along a conveyor that moves the pieces of foam 
to be glued together. Loop slitter adhesive use is a specialized type 
of foam fabrication adhesive use. Loop slitters are equipment used at 
slabstock foam production and/or fabrication facilities to slice large 
foam ``buns'' into thin sheets. Adhesive is used to attach the ends of 
the foam buns to one another before they are mounted on the loop 
slitter. The amount of adhesive used for loop slitters is relatively 
low because the adhesive is not applied continuously, just once or 
twice per shift when the foam buns are loaded onto the loop slitter. 
Flame lamination refers to the bonding of foam to any substrate (e.g., 
fabric, foam, plastic) where the bonding agent is scorched or melted 
foam. Thin sheets of foam are passed under a flame which scorches the 
foam surface and makes it sticky. The tacky foam sheet is then applied 
and adhered to a substrate.
    The Flexible Polyurethane Foam Production area source category 
includes facilities that manufacture foam made from polyurethanes, 
which are in the class of compounds called ``reaction polymers.'' 
Application of blowing agents, catalysts, surfactants, and fillers 
transforms the polyurethane into a foam with specialized properties. 
There are three types of polyurethane foam production facilities: 
Slabstock flexible polyurethane foam (slabstock foam), molded flexible 
polyurethane foam (molded foam), and rebond foam.

[[Page 1873]]

Slabstock foam is produced in large continuous buns that are then cut 
into the desired size and shape. Slabstock foam is used in a wide 
variety of applications, including furniture and mattresses. Molded 
foam is produced by ``shooting'' the foam mixture into a mold of the 
desired shape and size. Molded foam is used in office furniture, 
automobile seats, novelties, and many other applications. Rebond foam 
is made from scrap foam that is converted into a material primarily 
used for carpet underlay.
    The EPA estimates that there are 32 facilities currently subject to 
the area source standards, of which approximately 20 are believed to be 
owned by small businesses.
    The EPA promulgated MACT standards for major source Flexible 
Polyurethane Foam Fabrication Operations facilities in 2003 under 40 
CFR part 63, subpart MMMMM. The standards apply to major sources of HAP 
at existing and new flexible polyurethane foam fabrication facilities. 
Because of their potential to generate HAP emissions, the processing 
units of interest at foam fabrication facilities are loop slitters and 
flame lamination units. The MACT standards for Flexible Polyurethane 
Foam Fabrication Operations require HAP emissions reductions and 
control for new flame lamination units and prohibit use of HAP-based 
adhesives in new and existing loop slitting operations. For new flame 
lamination units, a 90-percent reduction in HAP emissions is required. 
For existing flame lamination units, there are currently no MACT 
emission limits. For new and existing loop slitters, the MACT standards 
prohibit use of any adhesive containing 5 percent or more (by weight) 
of total HAP. The EPA estimates that there are currently three 
facilities subject to subpart MMMMM--two in Indiana, and one in New 
Mexico.
    Both the Flexible Polyurethane Foam Production and Flexible 
Polyurethane Fabrication Operations area source categories were listed 
for regulation due to emissions of the urban HAP methylene chloride. At 
the time of the initial area source standards promulgation, methylene 
chloride was the only urban HAP used at foam production and foam 
fabrication facilities. Now, however, there are no known urban HAP used 
at foam production and foam fabrication facilities. In the past, 
slabstock foam production facilities sometimes used methylene chloride 
as an auxiliary blowing agent to control the density and other 
properties of the foam as it expanded during the pouring process.\2\ 
Methylene chloride was also sometimes used as an equipment cleaner, in 
particular for mix heads. A small number of molded and rebond foam 
facilities used methylene chloride in mold release agents, and some 
molded foam facilities used it as a mixhead cleaner. Foam fabricators 
used methylene chloride-based adhesives to adhere pieces of foam to one 
another. Flame laminators have never used methylene chloride and, as 
such, are not regulated by the area source standards.
---------------------------------------------------------------------------

    \2\ Other regulations address methylene chloride. For example, 
the EPA listed methylene chloride as an unacceptable (prohibited) 
blowing agent for use in flexible polyurethane under section 612 of 
the CAA (81 FR 86778, December 1, 2016).
---------------------------------------------------------------------------

    In 2007, the EPA promulgated GACT standards for the Flexible 
Polyurethane Foam Production area source category and the Flexible 
Polyurethane Foam Fabrication area source category together under 40 
CFR part 63, subpart OOOOOO. The GACT standards required that methylene 
chloride be significantly reduced or eliminated from slabstock foam 
production, molded foam release agents, equipment cleaning, rebond foam 
mold release agents, and from foam fabrication adhesive use. Although 
both area source categories were listed for regulation due to emissions 
of the urban HAP methylene chloride, the EPA finds that methylene 
chloride is no longer used within either source category.

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

    For the Flexible Foam Fabrication Operations NESHAP RTR, the EPA 
used emissions and supporting data from the 2017 and 2014 National 
Emissions Inventory (NEI), 2018 and 2019 Toxics Release Inventory (TRI) 
data, and 2014 stack test data from one facility to develop the model 
input files for the residual risk assessments for major source flexible 
foam fabrication facilities.
    The NEI is a database that contains information about sources that 
emit criteria air pollutants, their precursors, and HAP. The database 
includes estimates of annual air pollutant emissions from point, 
nonpoint, and mobile sources in the 50 states, the District of 
Columbia, Puerto Rico, and the U.S. Virgin Islands. The EPA collects 
this information and releases an updated version of the NEI database 
every 3 years. The NEI includes data necessary for conducting risk 
modeling, including annual HAP emissions estimates from individual 
emission sources at facilities and the related emissions release 
parameters. In certain cases, we contacted state inventory compilers 
and facility owners or operators to confirm and clarify the sources of 
emissions, emissions estimates, and release parameters that were 
reported in the NEI.
    The TRI is a resource for learning about toxic chemical releases 
and pollution prevention activities reported by industrial and federal 
facilities. The TRI tracks the management of certain toxic chemicals 
that may pose a threat to human health and the environment. U.S. 
facilities in different industry sectors must report annually how much 
of each chemical is released to the environment and/or managed through 
recycling, energy recovery, and treatment.\3\
---------------------------------------------------------------------------

    \3\ Available at https://www.epa.gov/toxics-release-inventory-tri-program.
---------------------------------------------------------------------------

    Additional information on the development of the modeling file can 
be found in Appendix 1 to the Residual Risk Assessment for the Flexible 
Polyurethane Foam Fabrication Operations Source Category in Support of 
the 2020 Risk and Technology Review Proposed Rule, which is available 
in the docket for this proposed rule (Docket ID No. EPA-HQ-OAR-2020-
0572).
    For the Flexible Foam Production and Fabrication area source 
standards, we relied on information provided by industry to determine 
whether any urban HAP were emitted from the regulated facilities. 
Through industry meetings and email and telephone conversations, the 
EPA found that there are no additional urban HAP emitted from flexible 
foam production and fabrication facilities subject to area source 
standards. Detailed information of the technology review can be found 
in the memorandum titled Technology Review for the Flexible 
Polyurethane Foam Production and Fabrication Area Source Categories, 
which is available in the docket for this proposed rule (Docket ID No. 
EPA-HQ-OAR-2020-0572).
    The Flexible Polyurethane Foam Production and Flexible Polyurethane 
Foam Fabrication MACT standards were promulgated in 1998 and 2003 
respectively. Since that time, the EPA has developed air toxics 
regulations for a number of additional source categories that emit HAP 
from the same types of emission sources that are present in the 
Flexible Polyurethane Foam Production and Fabrication source 
categories. In air toxic regulatory actions carried out subsequent to 
the initial MACT standard development for these source categories, the 
EPA has consistently evaluated any new practices, processes, and 
control technologies. A review of

[[Page 1874]]

these initial and subsequent air toxics regulations, including 
supporting documentation used in the rulemakings, was conducted to 
determine whether any practices, processes, or control technologies 
could be applied to the Flexible Foam Fabrication source category.
    One potential development in practices, processes, and control 
technologies was identified through the review of other air toxics 
regulations, which is discussed further in section IV.D of this 
document.

D. What other relevant background information and data are available?

    For the risk review portion of the RTR, we reviewed facility 
permits for the three major sources subjected to the Flexible 
Polyurethane Foam Fabrication Operations NESHAP. Facility permits 
provide data on maximum allowable emissions and other relevant 
production and emission factors.
    For the technology review portion of the RTR, we collected 
information from the Reasonably Available Control Technology, Best 
Available Control Technology, and Lowest Achievable Emission Rate 
Clearinghouse (RBLC) to identify developments in practices, processes, 
and control technologies since the MACT standards were developed. The 
RBLC is a database that contains case-specific information on air 
pollution technologies that have been required to reduce the emissions 
of air pollutants from stationary sources. Under the EPA's New Source 
Review (NSR) program, if a facility is planning new construction or a 
modification that will increase the air emissions above certain defined 
thresholds, an NSR permit must be obtained. The RBLC promotes the 
sharing of information among permitting agencies and aids in case-by-
case determinations for NSR permits. We examined information contained 
in the RBLC to determine what technologies are currently used for these 
source categories to reduce air emissions. Additional information about 
these data collection activities for the technology reviews is 
contained in the technology review memorandum titled Technology Review 
for the Flexible Polyurethane Foam Fabrication Operations Source 
Category, which is available in the docket for this proposed rule 
(Docket ID No. EPA-HQ-OAR-2020-0572).
    The RBLC provides several options for searching the permit database 
on-line to locate applicable control technologies. Our initial search 
of the RBLC specified processes in polyurethane foam products 
manufacturing, with permits dating back to 2001. This search did not 
provide any results for foam fabrication operations. Further searches 
of the database were conducted based on relevant keywords. The search 
included all available data fields, which among others, included the 
following:
     RBLC ID;
     Facility Name and State;
     Permit Date;
     Process name;
     Throughput;
     Pollutant;
     Control technology;
     Percent efficiency of control; and
     Pollutants/Compliance Notes.

The results of this search are presented in Appendix 1 of the 
Technology Review for the Flexible Polyurethane Foam Manufacturing 
Source Category. As shown in Appendix 1, no control technologies more 
stringent than the Flexible Polyurethane Foam NESHAP were identified 
through this search.
    Two of the three facilities subject to major source standards have 
loop slitter operations and use adhesives. Both facilities provided the 
EPA with safety data sheets (SDS) for the adhesives in use. Those SDS 
were used to determine chemical composition and potential HAP emissions 
from the adhesives. Additional background information on adhesive use 
and regulation was collected through review of other NESHAP in similar 
industrial sectors. Specifically, we searched for other NESHAP 
regulating HAP emissions from coatings and adhesives and compared the 
stringency of those standards to the existing requirements for HAP 
adhesives for loop slitters. Data from the SDS provided and the NESHAP 
for similar source categories were also used in the technology 
evaluation for the Flexible Polyurethane Foam Fabrication Operations 
NESHAP. The findings for the technology review are discussed further in 
section IV.D of this preamble.

III. Analytical Procedures and Decision-Making

    In this section, we describe the analyses performed to support the 
proposed decisions for the RTR and other issues addressed in this 
proposal.
    In this proposed action, pursuant to CAA section 112(f), the EPA is 
conducting a risk review for the major source NESHAP (40 CFR part 63, 
subpart MMMMM) MACT standards for Flexible Polyurethane Foam 
Fabrication Operations. Consistent with the provision regarding 
alternative standards for area sources in CAA section 112(d)(5), the 
risk review does not cover the NESHAP for area sources. Therefore, the 
discussions of risk assessment methods and modeling analyses described 
in the following paragraphs only apply to the major source category.
    However, pursuant to CAA section 112(d)(6), the EPA is proposing 
the technology review for both the major source NESHAP and the area 
source NESHAP (40 CFR part 63, subpart OOOOOO). Therefore, the 
discussions in the paragraphs below regarding how the EPA conducted the 
technology reviews apply to both major sources and area sources.

A. How do we consider risk in our decision-making?

    As discussed in section II.A of this preamble and in the Benzene 
NESHAP, in evaluating and developing standards under CAA section 
112(f)(2), we apply a two-step approach to determine whether or not 
risks are acceptable and to determine if the standards provide an ample 
margin of safety to protect public health. 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 section 112 is best judged on the basis of 
a broad set of health risk measures and information.'' (54 FR at 
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 approach provides flexibility regarding factors 
the EPA may consider in making determinations and how the EPA may weigh 
those factors for each source category. The EPA conducts a risk 
assessment that provides estimates of the MIR posed by emissions of HAP 
that are carcinogens from each source in the source category, the 
hazard index (HI) for chronic exposures to HAP with the potential to 
cause noncancer health effects, and the hazard quotient (HQ) for acute 
exposures to HAP with the potential to cause noncancer health 
effects.\4\ The assessment also provides estimates of the distribution 
of cancer

[[Page 1875]]

risk within the exposed populations, cancer incidence, and an 
evaluation of the potential for an adverse environmental effect. The 
scope of the EPA's risk analysis is consistent with the explanation in 
the EPA's response to comments on our policy under the Benzene NESHAP:
---------------------------------------------------------------------------

    \4\ The MIR is defined as the cancer risk associated with a 
lifetime of exposure at the highest concentration of HAP where 
people are likely to live. The HQ is the ratio of the potential HAP 
exposure concentration to the noncancer dose-response value; the HI 
is the sum of HQs for HAP that affect the same target organ or organ 
system.

    The policy chosen by the Administrator permits consideration of 
multiple measures of health risk. Not only can the MIR figure be 
considered, but also incidence, the presence of 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. This approach complies with the 
Vinyl Chloride mandate that the Administrator ascertain an 
acceptable level of risk to the public by employing his 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 his judgment, believes are 
---------------------------------------------------------------------------
appropriate to determining what will ``protect the public health''.

(54 FR at 38057). Thus, the level of the MIR is only one factor to be 
weighed in determining acceptability of risk. 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 an MIR less than the presumptively acceptable level 
is unacceptable in the light of other health risk factors.'' Id. at 
38045. In other words, risks that include an MIR above 100-in-1 million 
may be determined to be acceptable, and risks with an MIR below that 
level may be determined to be unacceptable, depending on all of the 
available health information. 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 the HAP risk that may be associated with emissions 
from other facilities that do not include the source category under 
review, mobile source emissions, natural source emissions, persistent 
environmental pollution, or atmospheric transformation in the vicinity 
of the sources in the category.
    The EPA 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 
noncancer risk, where pollutant-specific exposure health reference 
levels (e.g., reference concentrations (RfCs)) are based on the 
assumption that thresholds exist for adverse health effects. For 
example, the EPA recognizes that, although exposures attributable to 
emissions from a source category or facility alone may not indicate the 
potential for increased risk of adverse noncancer 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 an increased risk of adverse noncancer health effects. In May 
2010, the Science Advisory Board (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.'' \5\
---------------------------------------------------------------------------

    \5\ Recommendations of the SAB Risk and Technology Review 
Methods Panel are provided in their report, which is available at: 
https://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
---------------------------------------------------------------------------

    In response to the SAB recommendations, the EPA incorporates 
cumulative risk analyses into its RTR risk assessments. The Agency (1) 
conducts facility-wide assessments, which include source category 
emission points, as well as other emission points within the 
facilities; (2) combines exposures from multiple sources in the same 
category that could affect the same individuals; and (3) for some 
persistent and bioaccumulative pollutants, analyzes the ingestion route 
of exposure. In addition, the RTR risk assessments consider aggregate 
cancer risk from all carcinogens and aggregated noncancer HQs for all 
noncarcinogens affecting the same target organ or target organ system.
    Although we are interested in placing source category and facility-
wide HAP risk in the context of total HAP risk from all sources 
combined in the vicinity of each source, we are concerned about the 
uncertainties of doing so. Estimates of total HAP risk from emission 
sources other than those that we have studied in depth during this RTR 
review 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.

B. How do we perform the technology review?

    Our technology review primarily focuses on the identification and 
evaluation of developments in practices, processes, and control 
technologies that have occurred since the MACT standards were 
promulgated. Where we identify such developments, we analyze their 
technical feasibility, estimated costs, energy implications, and non-
air environmental impacts. We also consider the emission reductions 
associated with applying each development. This analysis informs our 
decision of whether it is ``necessary'' to revise the emissions 
standards. In addition, we consider the appropriateness of applying 
controls to new sources versus retrofitting existing sources. For this 
exercise, we consider 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; and

[[Page 1876]]

     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).
    In addition to reviewing the practices, processes, and control 
technologies that were considered at the time we originally developed 
the NESHAP, we review a variety of data sources in our investigation of 
potential practices, processes, or controls to consider. We also review 
the NESHAP and the available data to determine if there are any 
unregulated emissions of HAP within the source category and evaluate 
this data for use in developing new emission standards. See sections 
II.C and II.D of this preamble for information on the specific data 
sources that were reviewed as part of the technology review.

C. How do we estimate post-MACT risk posed by the source category?

    In this section, we provide a complete description of the types of 
analyses that we generally perform during the risk assessment process. 
In some cases, we do not perform a specific analysis because it is not 
relevant. For example, in the absence of emissions of HAP known to be 
persistent and bioaccumulative in the environment (PB-HAP), we would 
not perform a multipathway exposure assessment. Where we do not perform 
an analysis, we state that we do not and provide the reason. While we 
present all of our risk assessment methods, we only present risk 
assessment results for the analyses actually conducted (see section 
IV.B of this preamble).
    The EPA conducts a risk assessment that provides estimates of the 
MIR for cancer posed by the HAP emissions from each source in the 
source category, the HI for chronic exposures to HAP with the potential 
to cause noncancer health effects, and the HQ for acute exposures to 
HAP with the potential to cause noncancer health effects. The 
assessment also provides estimates of the distribution of cancer risk 
within the exposed populations, cancer incidence, and an evaluation of 
the potential for an adverse environmental effect. The seven sections 
that follow this paragraph describe how we estimated emissions and 
conducted the risk assessment. The docket for this proposed rule 
contains the following document that provides more information on the 
risk assessment inputs and models: Residual Risk Assessment for the 
Flexible Polyurethane Foam Fabrication Operations Source Category in 
Support of the 2020 Risk and Technology Review Proposed Rule. The 
methods used to assess risk (as described in the seven primary steps 
below) are consistent with those described by the EPA in the document 
reviewed by a panel of the EPA's SAB in 2009; \6\ and described in the 
SAB review report issued in 2010. They are also consistent with the key 
recommendations contained in that report.
---------------------------------------------------------------------------

    \6\ U.S. EPA. 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, June 2009. EPA-452/R-09-006. Available at: https://www3.epa.gov/airtoxics/rrisk/rtrpg.html.
---------------------------------------------------------------------------

1. How did we estimate actual emissions and identify the emissions 
release characteristics?
    The actual emissions and the emission release characteristics for 
each facility were obtained primarily from either the 2014 NEI or the 
2017 NEI; most data were obtained from the 2017 NEI, unless a facility 
was not included in that base year file, in which case the 2014 NEI 
data were used. In one instance, a facility was contacted to confirm 
emissions that appeared to be outliers because they were inconsistent 
with our understanding of the industry. That facility provided a test 
report containing data that were more consistent with our understanding 
of emissions from the industry and were ultimately used as actual 
emissions for the risk modeling file. Additional information on the 
development of the modeling file for the Flexible Polyurethane Foam 
Fabrication Operations source category, including the development of 
the actual emissions and emissions release characteristics, can be 
found in the memorandum, Emissions Data for the National Emission 
Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam 
Fabrication Operations, which is available in the respective docket for 
this action.
2. How did we estimate MACT-allowable emissions?
    The available emissions data in the RTR emissions dataset include 
estimates of the mass of HAP emitted during a specified annual time 
period. These ``actual'' emission levels are often lower than the 
emission levels allowed under the requirements of the current MACT 
standards. The emissions allowed under the MACT standards are referred 
to as the ``MACT-allowable'' emissions. We discussed the consideration 
of both MACT-allowable and actual emissions in the final Coke Oven 
Batteries RTR (70 FR 19992, 19998 and 19999, April 15, 2005) and in the 
proposed and final Hazardous Organic NESHAP RTR (71 FR 34421, 34428, 
June 14, 2006, and 71 FR 76603, 76609, December 21, 2006, 
respectively). In those actions, we noted that assessing the risk at 
the MACT-allowable level is inherently reasonable since that risk 
reflects 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 approach 
(54 FR 38044).
    For the Flexible Polyurethane Foam Fabrication Operations source 
category, allowable emissions were assumed to be equal to actual 
emissions. For the subcategory of flame laminators, there currently are 
no emissions limits for existing sources, and there have been no new 
sources since the promulgation of the standards. Therefore, we conclude 
that the emissions that are allowed under the existing standards are 
equal to actual emissions. For the loop slitter subcategory, there were 
no HAP emissions from the adhesive, and we are not aware of any HAP-
based substitutes that could be used in place of current industry 
practice; therefore, we again conclude that allowable emissions would 
be equal to actual emissions, which in this case are zero.
3. How do we conduct dispersion modeling, determine inhalation 
exposures, and estimate individual and population inhalation risk?
    Both long-term and short-term inhalation exposure concentrations 
and health risk from the major source category addressed in this 
proposal were estimated using the Human Exposure Model (HEM-3).\7\ 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, 
and (3) estimating individual and population-level inhalation risk 
using the exposure estimates and quantitative dose-response 
information.
---------------------------------------------------------------------------

    \7\ For more information about HEM-3, go to https://www.epa.gov/fera/risk-assessment-and-modeling-human-exposure-model-hem.
---------------------------------------------------------------------------

a. Dispersion Modeling
    The air dispersion model AERMOD, used by the HEM-3 model, is one of 
the EPA's preferred models for assessing air pollutant concentrations 
from industrial

[[Page 1877]]

facilities.\8\ 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 (2016) of hourly surface and 
upper air observations from 824 meteorological stations selected to 
provide coverage of the United States and Puerto Rico. A second library 
of United States Census Bureau census block \9\ 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-specific dose-response values is used to estimate health 
risk. These are discussed below.
---------------------------------------------------------------------------

    \8\ 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).
    \9\ A census block is the smallest geographic area for which 
census statistics are tabulated.
---------------------------------------------------------------------------

b. Risk From Chronic Exposure to HAP
    In developing the risk assessment for chronic exposures, we use the 
estimated annual average ambient air concentrations of each HAP emitted 
by each source in the major source category. The HAP air concentrations 
at each nearby census block centroid located within 50 km of the 
facility are a surrogate for the chronic inhalation exposure 
concentration for all the people who reside in that census block. A 
distance of 50 km is consistent with both the analysis supporting the 
1989 Benzene NESHAP (54 FR 38044, September 14, 1989) and the 
limitations of Gaussian dispersion models, including AERMOD.
    For each facility, we calculate the MIR as the cancer risk 
associated with a continuous lifetime (24 hours per day, 7 days per 
week, 52 weeks per year, 70 years) exposure to the maximum 
concentration at the centroid of each inhabited census block. We 
calculate individual cancer risk by multiplying the estimated lifetime 
exposure to the ambient concentration of each HAP (in micrograms per 
cubic meter) by its unit risk estimate (URE). The URE is an upper-bound 
estimate of an individual's incremental risk 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 UREs from the EPA's Integrated Risk Information System 
(IRIS). For carcinogenic pollutants without IRIS values, we look to 
other reputable sources of cancer dose-response values, often using 
California EPA (CalEPA) UREs, 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-
response values in place of, or in addition to, other values, if 
appropriate. The pollutant-specific dose-response values used to 
estimate health risk are available at https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants.
    To estimate individual lifetime cancer risks associated with 
exposure to HAP emissions from each facility in the source category, we 
sum the risks for each of the carcinogenic HAP \10\ emitted by the 
modeled facility. We estimate cancer risk at every census block within 
50 km of every facility in the source category. The MIR is the highest 
individual lifetime cancer risk estimated for any of those census 
blocks. In addition to calculating the MIR, we estimate the 
distribution of individual cancer risks for the source category by 
summing the number of individuals within 50 km of the sources whose 
estimated risk falls within a specified risk range. We also estimate 
annual cancer incidence by multiplying the estimated lifetime cancer 
risk at each census block by the number of people residing in that 
block, summing results for all of the census blocks, and then dividing 
this result by a 70-year lifetime.
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    \10\ The EPA's 2005 Guidelines for Carcinogen Risk Assessment 
classifies carcinogens as: ``carcinogenic to humans,'' ``likely to 
be carcinogenic to humans,'' and ``suggestive evidence of 
carcinogenic potential.'' These classifications also coincide with 
the terms ``known carcinogen, probable carcinogen, and possible 
carcinogen,'' respectively, which are the terms advocated in the 
EPA's Guidelines for Carcinogen Risk Assessment, published in 1986 
(51 FR 33992, September 24, 1986). In August 2000, the document, 
Supplemental Guidance for Conducting Health Risk Assessment of 
Chemical Mixtures (EPA/630/R-00/002), was published as a supplement 
to the 1986 document. Copies of both documents can be obtained from 
https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=20533&CFID=70315376&CFTOKEN=71597944. Summing 
the risk of these individual compounds to obtain the cumulative 
cancer risk is an approach that was recommended by the EPA's SAB in 
their 2002 peer review of the EPA's National Air Toxics Assessment 
(NATA) titled NATA--Evaluating the National-scale Air Toxics 
Assessment 1996 Data--an SAB Advisory, available at https://
yosemite.epa.gov/sab/sabproduct.nsf/
214C6E915BB04E14852570CA007A682C/$File/ecadv02001.pdf.
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    To assess the risk of noncancer health effects from chronic 
exposure to HAP, we calculate either an HQ or a target organ-specific 
hazard index (TOSHI). We calculate an HQ when a single noncancer HAP is 
emitted. Where more than one noncancer HAP is emitted, we sum the HQ 
for each of the HAP that affects a common target organ or target organ 
system to obtain a TOSHI. The HQ is the estimated exposure divided by 
the chronic noncancer dose-response value, which is a value selected 
from one of several sources. The preferred chronic noncancer dose-
response value is the EPA RfC, defined as ``an estimate (with 
uncertainty spanning perhaps an order of magnitude) of a continuous 
inhalation exposure to the human population (including sensitive 
subgroups) that is likely to be without an appreciable risk of 
deleterious effects during a lifetime'' (https://iaspub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&vocabName=IRIS%20Glossary). In cases where an RfC 
from the EPA's IRIS is not available or where the EPA determines that 
using a value other than the RfC is appropriate, the chronic noncancer 
dose-response value can be a value from the following prioritized 
sources, which define their dose-response values similarly to the EPA: 
(1) The Agency for Toxic Substances and Disease Registry (ATSDR) 
Minimum Risk Level (https://www.atsdr.cdc.gov/mrls/index.asp); (2) the 
CalEPA Chronic Reference Exposure Level (REL) (https://oehha.ca.gov/air/crnr/notice-adoption-air-toxics-hot-spots-program-guidance-manual-preparation-health-risk-0); 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. The pollutant-specific dose-
response values used to estimate health risks are available at https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants.
c. Risk From Acute Exposure to HAP That May Cause Health Effects Other 
Than Cancer
    For each HAP for which appropriate acute inhalation dose-response 
values are available, the EPA also assesses the potential health risks 
due to acute exposure. For these assessments, the EPA makes 
conservative assumptions about emission rates, meteorology, and 
exposure location. As part of our efforts to continually improve our

[[Page 1878]]

methodologies to evaluate the risks that HAP emitted from categories of 
industrial sources pose to human health and the environment,\11\ we 
revised our treatment of meteorological data to use reasonable worst-
case air dispersion conditions in our acute risk screening assessments 
instead of worst-case air dispersion conditions. This revised treatment 
of meteorological data and the supporting rationale are described in 
more detail in Residual Risk Assessment for Flexible Polyurethane Foam 
Fabrication Operations Source Category in Support of the 2020 Risk and 
Technology Review Proposed Rule and in Appendix 5 of the report: 
Technical Support Document for Acute Risk Screening Assessment. This 
revised approach has been used in this proposed rule and in all other 
RTR rulemakings proposed on or after June 3, 2019.
---------------------------------------------------------------------------

    \11\ See, e.g., U.S. EPA, Screening Methodologies to Support 
Risk and Technology Reviews (RTR): A Case Study Analysis (Draft 
Report, May 2017). https://www3.epa.gov/ttn/atw/rrisk/rtrpg.html.
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    To assess the potential acute risk to the maximally exposed 
individual, we use the peak hourly emission rate for each emission 
point,\12\ reasonable worst-case air dispersion conditions (i.e., 99th 
percentile), and the point of highest off-site exposure. Specifically, 
we assume that peak emissions from the source category and reasonable 
worst-case air dispersion conditions co-occur and that a person is 
present at the point of maximum exposure.
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    \12\ In the absence of hourly emission data, we develop 
estimates of maximum hourly emission rates by multiplying the 
average actual annual emissions rates by a factor (either a 
category-specific factor or a default factor of 10) to account for 
variability. This is documented in Residual Risk Assessment for 
Flexible Polyurethane Foam Fabrication Operations Source Category in 
Support of the 2020 Risk and Technology Review Proposed Rule and in 
Appendix 5 of the report: Technical Support Document for Acute Risk 
Screening Assessment. Both are available in the docket for this 
rulemaking.
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    To characterize the potential health risks associated with 
estimated acute inhalation exposures to a HAP, we generally use 
multiple acute dose-response values, including acute RELs, acute 
exposure guideline levels (AEGLs), and emergency response planning 
guidelines (ERPG) for 1-hour exposure durations, if available, to 
calculate acute HQs. The acute HQ is calculated by dividing the 
estimated acute exposure concentration by the acute dose-response 
value. For each HAP for which acute dose-response values are available, 
the EPA calculates acute HQs.
    An acute REL is defined as ``the concentration level at or below 
which no adverse health effects are anticipated for a specified 
exposure duration.'' \13\ Acute RELs are based on the most sensitive, 
relevant, adverse health effect reported in the peer-reviewed medical 
and toxicological literature. They are designed to protect the most 
sensitive individuals in the population through 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. AEGLs represent 
threshold exposure limits for the general public and are applicable to 
emergency exposures ranging from 10 minutes to 8 hours.\14\ They are 
guideline levels for ``once-in-a-lifetime, short-term exposures to 
airborne concentrations of acutely toxic, high-priority chemicals.'' 
Id. at 21. The AEGL-1 is 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.'' The document also notes that ``Airborne concentrations 
below AEGL-1 represent exposure levels that can produce mild and 
progressively increasing but transient and nondisabling odor, taste, 
and sensory irritation or certain asymptomatic, nonsensory effects.'' 
Id. AEGL-2 are defined 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.
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    \13\ CalEPA issues acute RELs as part of its Air Toxics Hot 
Spots Program, and the 1-hour and 8-hour values are documented in 
Air Toxics Hot Spots Program Risk Assessment Guidelines, Part I, The 
Determination of Acute Reference Exposure Levels for Airborne 
Toxicants, which is available at https://oehha.ca.gov/air/general-info/oehha-acute-8-hour-and-chronic-reference-exposure-level-rel-summary.
    \14\ National Academy of Sciences, 2001. Standing Operating 
Procedures for Developing Acute Exposure Levels for Hazardous 
Chemicals, page 2. Available at https://www.epa.gov/sites/production/files/2015-09/documents/sop_final_standing_operating_procedures_2001.pdf. Note that the 
National Advisory Committee for Acute Exposure Guideline Levels for 
Hazardous Substances ended in October 2011, but the AEGL program 
continues to operate at the EPA and works with the National 
Academies to publish final AEGLs (https://www.epa.gov/aegl).
---------------------------------------------------------------------------

    ERPGs are ``developed for emergency planning and are intended as 
health-based guideline concentrations for single exposures to 
chemicals.'' \15\ Id. at 1. The ERPG-1 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 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.
---------------------------------------------------------------------------

    \15\ ERPGS Procedures and Responsibilities. March 2014. American 
Industrial Hygiene Association. Available at: https://www.aiha.org/get-involved/AIHAGuidelineFoundation/EmergencyResponsePlanningGuidelines/Documents/ERPG%20Committee%20Standard%20Operating%20Procedures%20%20-%20March%202014%20Revision%20%28Updated%2010-2-2014%29.pdf.
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    An acute REL for 1-hour exposure durations is typically lower than 
its corresponding AEGL-1 and ERPG-1. Even though their definitions are 
slightly different, AEGL-1s are often the same as the corresponding 
ERPG-1s, and AEGL-2s are often equal to ERPG-2s. The maximum HQs from 
our acute inhalation screening risk assessment typically result when we 
use the acute REL for a HAP. In cases where the maximum acute HQ 
exceeds 1, we also report the HQ based on the next highest acute dose-
response value (usually the AEGL-1 and/or the ERPG-1).
    For this source category, we used a default multiplier of 10 to 
provide a conservatively high estimate of acute effects.
    In our acute inhalation screening risk assessment, acute impacts 
are deemed negligible for HAP for which acute HQs are less than or 
equal to 1, and no further analysis is performed for these HAP. In 
cases where an acute HQ from the screening step is greater than 1, we 
assess the site-specific data to ensure that the acute HQ is at an off-
site location.
4. How do we conduct the multipathway exposure and risk screening 
assessment?
    The EPA conducts a tiered screening assessment examining the 
potential for significant human health risks due to exposures via 
routes other than inhalation (i.e., ingestion). We first determine 
whether any sources in the source category emit any HAP known to be 
persistent and bioaccumulative in the environment, as identified in the 
EPA's

[[Page 1879]]

Air Toxics Risk Assessment Library (see Volume 1, Appendix D, at 
https://www.epa.gov/fera/risk-assessment-and-modeling-air-toxics-risk-assessment-reference-library). For the Flexible Polyurethane Foam 
Fabrication Operations source category, we did not identify emissions 
of any PB-HAP. Because we did not identify PB-HAP emissions, no further 
evaluation of multipathway risk was conducted for this source category.
    For further information on the multipathway assessment approach, 
see the Residual Risk Assessment for the Flexible Polyurethane Foam 
Fabrication Operations Source Category in Support of the 2020 Risk and 
Technology Review Proposed Rule, which is available in the docket for 
this action.
5. How do we conduct the environmental risk screening assessment?
a. Adverse Environmental Effect, Environmental HAP, and Ecological 
Benchmarks
    The EPA conducts a screening assessment to examine the potential 
for an adverse environmental effect 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.''
    The EPA focuses on eight HAP, which are referred to as 
``environmental HAP,'' in its screening assessment: Six PB-HAP and two 
acid gases. The PB-HAP included in the screening assessment are arsenic 
compounds, cadmium compounds, dioxins/furans, polycyclic organic matter 
(POM), mercury (both inorganic mercury and methyl mercury), and lead 
compounds. The acid gases included in the screening assessment are 
hydrochloric acid (HCl) and hydrogen fluoride (HF).
    HAP that persist and bioaccumulate are of particular environmental 
concern because they accumulate in the soil, sediment, and water. The 
acid gases, HCl and HF, are included due to their well-documented 
potential to cause direct damage to terrestrial plants. In the 
environmental risk screening assessment, we evaluate the following four 
exposure media: Terrestrial soils, surface water bodies (includes 
water-column and benthic sediments), fish consumed by wildlife, and 
air. Within these four exposure media, we evaluate nine ecological 
assessment endpoints, which are defined by the ecological entity and 
its attributes. For PB-HAP (other than lead), both community-level and 
population-level endpoints are included. For acid gases, the ecological 
assessment evaluated is terrestrial plant communities.
    An ecological benchmark represents a concentration of HAP that has 
been linked to a particular environmental effect level. For each 
environmental HAP, we identified the available ecological benchmarks 
for each assessment endpoint. We identified, where possible, ecological 
benchmarks at the following effect levels: probable effect levels, 
lowest-observed-adverse-effect level, and no-observed-adverse-effect 
level. In cases where multiple effect levels were available for a 
particular PB-HAP and assessment endpoint, we use all of the available 
effect levels to help us to determine whether ecological risks exist 
and, if so, whether the risks could be considered significant and 
widespread.
    For further information on how the environmental risk screening 
assessment was conducted, including a discussion of the risk metrics 
used, how the environmental HAP were identified, and how the ecological 
benchmarks were selected, see Appendix 9 of the Residual Risk 
Assessment for the Flexible Polyurethane Foam Fabrication Operations 
Source Category in Support of the 2020 Risk and Technology Review 
Proposed Rule, which is available in the docket for this action.
b. Environmental Risk Screening Methodology
    For the environmental risk screening assessment, the EPA first 
determined whether any facilities in the Flexible Polyurethane Foam 
Fabrication Operations source category emitted any of the environmental 
HAP. For the Flexible Polyurethane Foam Fabrication Operations source 
category, we identified emissions of HCl. Because one or more of the 
environmental HAP evaluated emitted HCl by at least one facility in the 
source category, we proceeded to the second step of the evaluation.
c. PB-HAP Methodology
    The environmental screening assessment includes six PB-HAP, arsenic 
compounds, cadmium compounds, dioxins/furans, POM, mercury (both 
inorganic mercury and methyl mercury), and lead compounds. For the 
Flexible Polyurethane Foam Fabrication Operations source category, we 
did not identify emissions of any PB-HAP. Because we did not identify 
PB-HAP emissions, no further evaluation of PB-HAP for the environmental 
risk assessment was conducted for this source category.
    For further information on the PB-HAP environmental assessment 
approach, see the Residual Risk Assessment for the Flexible 
Polyurethane Foam Fabrication Operations Source Category in Support of 
the 2020 Risk and Technology Review Proposed Rule, available in the 
docket for this proposed rule (Docket ID No. EPA-HQ-OAR-2020-0572).
d. Acid Gas Environmental Risk Methodology
    The environmental screening assessment for acid gases evaluates the 
potential phytotoxicity and reduced productivity of plants due to 
chronic exposure to HF and HCl. The environmental risk screening 
methodology for acid gases is a single-tier screening assessment that 
compares modeled ambient air concentrations (from AERMOD) to the 
ecological benchmarks for each acid gas. To identify a potential 
adverse environmental effect (as defined in section 112(a)(7) of the 
CAA) from emissions of HF and HCl, we evaluate the following metrics: 
The size of the modeled area around each facility that exceeds the 
ecological benchmark for each acid gas, in acres and square kilometers; 
the percentage of the modeled area around each facility that exceeds 
the ecological benchmark for each acid gas; and the area-weighted 
average screening value around each facility (calculated by dividing 
the area-weighted average concentration over the 50-km modeling domain 
by the ecological benchmark for each acid gas). For further information 
on the environmental screening assessment approach, see Appendix 9 of 
the Residual Risk Assessment for the Flexible Polyurethane Foam 
Fabrication Operations Source Category in Support of the 2020 Risk and 
Technology Review Proposed Rule, which is available in the docket for 
this action.
6. How do 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 emission sources at the facility for which we have data. 
For

[[Page 1880]]

this source category, we conducted the facility-wide assessment using a 
dataset compiled from the 2014 and 2017 NEI. The source category 
records of that NEI dataset were removed, evaluated, and updated as 
described in section II.C of this preamble: What data collection 
activities were conducted to support this action? Once a quality 
assured source category dataset was available, it was placed back with 
the remaining records from the NEI for that facility. The facility-wide 
file was then used to analyze risks due to the inhalation of HAP that 
are emitted ``facility-wide'' for the populations residing within 50 km 
of each facility, consistent with the methods used for the source 
category analysis described above. For these facility-wide risk 
analyses, the modeled source category risks were compared to the 
facility-wide risks to determine the portion of the facility-wide risks 
that could be attributed to the source category addressed in this 
proposal. We also specifically examined the facility that was 
associated with the highest estimate of risk and determined the 
percentage of that risk attributable to the source category of 
interest. The Residual Risk Assessment for the Flexible Polyurethane 
Foam Fabrication Operations Source Category in Support of the 2020 Risk 
and Technology Review Proposed Rule, available through the docket for 
this action, provides the methodology and results of the facility-wide 
analyses, including all facility-wide risks and the percentage of 
source category contribution to facility-wide risks.
7. How do we consider uncertainties in risk assessment?
    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 approach, which used 
conservative tools and assumptions, ensures that our decisions are 
health and environmentally protective. A brief discussion of the 
uncertainties in the RTR emissions dataset, dispersion modeling, 
inhalation exposure estimates, and dose-response relationships follows 
below. Also included are those uncertainties specific to our acute 
screening assessments, multipathway screening assessments, and our 
environmental risk screening assessments. A more thorough discussion of 
these uncertainties is included in the Residual Risk Assessment for the 
Flexible Polyurethane Foam Fabrication Operations Source Category in 
Support of the 2020 Risk and Technology Review Proposed Rule, which is 
available in the docket for this action. If a multipathway site-
specific assessment was performed for this source category, a full 
discussion of the uncertainties associated with that assessment can be 
found in Appendix 11 of that document, Site-Specific Human Health 
Multipathway Residual Risk Assessment Report.
a. Uncertainties in the RTR Emissions Dataset
    Although the development of the RTR emissions 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 emission 
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 emission 
rates for the acute effects screening assessment were based on an 
emission adjustment factor applied to the average annual hourly 
emission 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 estimate 
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 overestimate 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. We also note that the selection of meteorology dataset 
location could have an impact on the risk estimates. As we continue to 
update and expand our library of meteorological station data used in 
our risk assessments, we expect to reduce this variability.
c. Uncertainties in Inhalation Exposure Assessment
    Although every effort is made to identify all of the relevant 
facilities and emission points, as well as to develop accurate 
estimates of the annual emission rates for all relevant HAP, the 
uncertainties in our emission inventory likely dominate the 
uncertainties in the exposure assessment. Some uncertainties in our 
exposure assessment include human mobility, using the centroid of each 
census block, assuming lifetime exposure, and assuming only outdoor 
exposures. For most of these factors, there is neither an under nor 
overestimate when looking at the MIR or the incidence, but the shape of 
the distribution of risks may be affected. With respect to outdoor 
exposures, actual exposures may not be as high if people spend time 
indoors, especially for very reactive pollutants or larger particles. 
For all factors, we reduce uncertainty when possible. For example, with 
respect to census-block centroids, we analyze large blocks using aerial 
imagery and adjust locations of the block centroids to better represent 
the population in the blocks. We also add additional receptor locations 
where the population of a block is not well represented by a single 
location.
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 noncancer effects from both chronic and acute 
exposures. Some uncertainties are generally expressed quantitatively, 
and others are generally expressed in qualitative terms. We note, as a 
preface to this discussion, a point on dose-response uncertainty that 
is stated in the EPA's 2005 Guidelines for Carcinogen Risk Assessment; 
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'' (the EPA's 2005 
Guidelines for Carcinogen Risk Assessment, page 1-7). This is the 
approach followed here as summarized in the next paragraphs.
    Cancer UREs used in our risk assessments are those that have been 
developed to generally provide an upper

[[Page 1881]]

bound estimate of risk.\16\ 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). In some circumstances, the true 
risk could be as low as zero; however, in other circumstances the risk 
could be greater.\17\ Chronic noncancer RfC and reference dose (RfD) 
values represent chronic exposure levels that are intended to be 
health-protective levels. To derive dose-response values that are 
intended to be ``without appreciable risk,'' the methodology relies 
upon an uncertainty factor (UF) approach,\18\ which considers 
uncertainty, variability, and gaps in the available data. The UFs are 
applied to derive dose-response values that are intended to protect 
against appreciable risk of deleterious effects.
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    \16\ IRIS glossary (https://ofmpub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&glossaryName=IRIS%20Glossary).
    \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.
    \18\ See A Review of the Reference Dose and Reference 
Concentration Processes, U.S. EPA, December 2002, and Methods for 
Derivation of Inhalation Reference Concentrations and Application of 
Inhalation Dosimetry, U.S. EPA, 1994.
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    Many of the UFs used to account for variability and uncertainty in 
the development of acute dose-response values are quite similar to 
those developed for chronic durations. 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 dose-
response value at another exposure duration (e.g., 1 hour). Not all 
acute dose-response 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 dose-response value or values 
being exceeded. Where relevant to the estimated exposures, the lack of 
acute dose-response values at different levels of severity should be 
factored into the risk characterization as potential uncertainties.
    Uncertainty also exists in the selection of ecological benchmarks 
for the environmental risk screening assessment. We established a 
hierarchy of preferred benchmark sources to allow selection of 
benchmarks for each environmental HAP at each ecological assessment 
endpoint. We searched for benchmarks for three effect levels (i.e., no-
effects level, threshold-effect level, and probable effect level), but 
not all combinations of ecological assessment/environmental HAP had 
benchmarks for all three effect levels. Where multiple effect levels 
were available for a particular HAP and assessment endpoint, we used 
all of the available effect levels to help us determine whether risk 
exists and whether the risk could be considered significant and 
widespread.
    For a group of compounds that are unspeciated (e.g., glycol 
ethers), we conservatively use the most protective dose-response 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 dose-response value, we also 
apply the most protective dose-response value from the other compounds 
in the group to estimate risk.
e. Uncertainties in Acute Inhalation Screening Assessments
    In addition to the uncertainties highlighted above, there are 
several factors specific to the acute exposure assessment that the EPA 
conducts as part of the risk review under section 112 of the CAA. 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 the presence of a 
person. In the acute screening assessment that we conduct under the RTR 
program, we assume that peak emissions from the source category and 
reasonable worst-case air dispersion conditions (i.e., 99th percentile) 
co-occur. We then include the additional assumption that a person is 
located at this point at the same time. Together, these assumptions 
represent a reasonable worst-case actual exposure scenario. In most 
cases, it is unlikely that a person would be located at the point of 
maximum exposure during the time when peak emissions and reasonable 
worst-case air dispersion conditions occur simultaneously.
f. Uncertainties in the Multipathway and Environmental Risk Screening 
Assessments
    For each source category, we generally rely on site-specific levels 
of PB-HAP or environmental HAP emissions to determine whether a refined 
assessment of the impacts from multipathway exposures is necessary or 
whether it is necessary to perform an environmental screening 
assessment. This determination is based on the results of a three-
tiered screening assessment that relies on the outputs from models--
Total Risk Integrated Methodology.Fate, Transport, and Ecological 
Exposure model (TRIM.FaTE) and AERMOD--that estimate environmental 
pollutant concentrations and human exposures for five PB-HAP (dioxins, 
POM, mercury, cadmium, and arsenic) and two acid gases (HF and HCl). 
For lead, we use AERMOD to determine ambient air concentrations, which 
are then compared to the secondary National Ambient Air Quality 
Standards for lead. 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\
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    \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.
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    Model uncertainty concerns whether the model adequately represents 
the actual processes (e.g., movement and accumulation) that might occur 
in the environment. For example, does the model adequately describe the 
movement of a pollutant through the soil? This type of uncertainty is 
difficult to quantify. However, based on feedback received from 
previous EPA SAB reviews and other reviews, we are confident that the 
models used in the screening assessments are appropriate and state-of-
the-art for the multipathway and environmental screening risk 
assessments conducted in support of RTRs.
    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 and environmental screening assessments, we 
configured the models to avoid underestimating exposure and risk. This 
was accomplished by selecting upper-end values from nationally 
representative datasets 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, 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 and environmental screening 
assessments, we refine the model inputs to account for meteorological 
patterns in the vicinity of the facility versus using

[[Page 1882]]

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 screening assessment. In Tier 3 of the 
screening assessments, we refine the model inputs again to account for 
hour-by-hour plume-rise and the height of the mixing layer. We can also 
use those hour-by-hour meteorological data in a TRIM.FaTE run using the 
screening configuration corresponding to the lake location. These 
refinements produce a more accurate estimate of chemical concentrations 
in the media of interest, thereby reducing the uncertainty with those 
estimates. The assumptions and the associated uncertainties regarding 
the selected ingestion exposure scenario are the same for all three 
tiers.
    For the environmental screening assessment for acid gases, we 
employ a single-tiered approach. We use the modeled air concentrations 
and compare those with ecological benchmarks.
    For all tiers of the multipathway and environmental screening 
assessments, 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 not exceed screening threshold emission rates (i.e., 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 exceed screening threshold emission rates, it does not 
mean that impacts are significant, only that we cannot rule out that 
possibility and that a refined assessment for the site might be 
necessary to obtain a more accurate risk characterization for the 
source category.
    The EPA evaluates the following HAP in the multipathway and/or 
environmental risk screening assessments, where applicable: Arsenic, 
cadmium, dioxins/furans, lead, mercury (both inorganic and methyl 
mercury), POM, HCl, and HF. These HAP represent pollutants that can 
cause adverse impacts either through direct exposure to HAP in the air 
or through exposure to HAP that are deposited from the air onto soils 
and surface waters and then through the environment into the food web. 
These HAP represent those HAP for which we can conduct a meaningful 
multipathway or environmental screening risk assessment. For other HAP 
not included in our screening assessments, the model has not been 
parameterized such that it can be used for that purpose. In some cases, 
depending on the HAP, we may not have appropriate multipathway models 
that allow us to predict the concentration of that pollutant. The EPA 
acknowledges that other HAP beyond these that we are evaluating may 
have the potential to cause adverse effects and, therefore, the EPA may 
evaluate other relevant HAP in the future, as modeling science and 
resources allow.

IV. Analytical Results and Proposed Decisions

A. What actions are we taking pursuant to CAA sections 112(d)(2) and 
112(d)(3) for the Flexible Polyurethane Foam Fabrication Operations 
source category?

    We are proposing pursuant to CAA section 112(d)(2) and (3) to 
establish a numeric limit for HCl emissions from existing flame 
laminators. The results and proposed decisions based on the analyses 
performed pursuant to CAA section 112(d)(2) and (3) are presented 
below.
    For the Flexible Polyurethane Foam Fabrication Operations source 
category, there are four unregulated existing source flame laminators 
at two facilities. For major sources, the EPA is required to set 
technology-based standards that reflect the maximum reductions of HAP 
achievable (after considering cost, energy requirements, and non-air 
health and environmental impacts) and are commonly referred to as MACT 
standards. Furthermore, CAA section 112(d)(3)(B) provides that MACT 
shall not be less stringent than ``the average emission limitation 
achieved by the best performing five sources (for which the 
Administrator has or could reasonably obtain emissions information) in 
the category for categories with fewer than 30 sources. In this 
category, the MACT floor for existing sources is the average (or mean) 
of the four known flame lamination sources. However, emissions data for 
HCl emissions from only one of these units is available. As this is the 
only unit of which we are aware that has had emissions testing 
conducted for HCl, the proposed MACT floor is based on the HCl data for 
this unit. In order to determine the level of the MACT floor, the Upper 
Prediction Limit method was used in order to account for variability in 
flame laminator emissions performance, and the MACT floor was 
calculated at 1.45 pounds per hour of HCl.\20\
---------------------------------------------------------------------------

    \20\ MACT Floor and Beyond-the-Floor Analysis for Existing Flame 
Laminators in the Flexible Polyurethane Foam Fabrication Source 
Category (EPA-HQ-OAR-2020-0572).
---------------------------------------------------------------------------

    When establishing an emission standard pursuant to section 112 of 
the CAA, the EPA must also determine whether to control emissions 
``beyond the floor'' after considering the costs, non-air quality 
health and environmental impacts, and energy requirements of such more 
stringent control. For the existing source flame laminators, the EPA 
evaluated whether a beyond-the-floor emissions limit would be 
appropriate; specifically, we evaluated whether the incremental 
emissions reduction achievable with a venturi scrubber would be cost 
effective. The venturi scrubber was the only control technology in use 
at flame lamination sources that was identified by the EPA with the 
initial promulgation of the NESHAP, and no other developments in 
control technologies were identified in the review of these standards. 
The EPA's previous cost estimates of this technology conducted for the 
proposal of the NESHAP in 2001 showed that the average cost per ton of 
HCl emissions reduced was approximately $18,000. As nothing has 
substantially changed with this technology or in how it would be 
implemented, the EPA assumes that the cost effectiveness today would be 
similar to that previously estimated, once the costs of inflation are 
considered. Inflated to 2020 dollars, the average incremental cost per 
ton of HCl emissions reduced is estimated to be approximately $26,000. 
We do not find this to be cost effective for the control of HCl and, 
therefore, propose that floor-level MACT controls are appropriate for 
existing flame laminators.

B. What are the results of the risk assessment and analyses for the 
Flexible Polyurethane Foam Fabrication Operations source category?

    As described in section III.C of this preamble, for the Flexible 
Polyurethane Foam Fabrication Operations major source category, we 
conducted a risk assessment for all HAP emitted. We present results of 
the risk assessment briefly below and in more detail in the Flexible 
Polyurethane Foam Fabrication Risk Assessment Report, in the docket for 
this action (Docket ID No. EPA-HQ-OAR-2020-0572).

[[Page 1883]]

1. Chronic Inhalation Risk Assessment Results
    Table 1 below provides a summary of the results of the inhalation 
risk assessment for the source category. As discussed in section III.C 
of this preamble, we set MACT-allowable HAP emission levels equal to 
actual emissions. For more detail about the MACT-allowable emission 
levels, see Appendix 1 to the Flexible Polyurethane Foam Fabrication 
Risk Assessment Report, in the docket for this action.

                           Table 1--Flexible Polyurethane Foam Fabrication Source Category Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                  Maximum individual      Estimated population at   Estimated annual cancer       Maximum chronic      Maximum screening
                                  cancer risk  (in 1     increased risk of cancer    incidence  (cases per     noncancer TOSHI \21\     acute noncancer
                                       million)              >= 1-in-1 million               year)          --------------------------       HQ\22\
       Risk assessment        ------------------------------------------------------------------------------                          ------------------
                                 Based on     Based on     Based on     Based on     Based on     Based on     Based on     Based on
                                  actual     allowable      actual     allowable      actual     allowable      actual     allowable    Based on actual
                                emissions    Emissions    emissions    emissions    emissions    emissions    emissions    emissions       emissions
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source category..............            0            0            0            0            0            0        0.002        0.002         HQREL = <1
Whole Facility...............          0.1  ...........            0  ...........      0.00001  ...........          0.2  ...........  .................
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The results of  the inhalation risk modeling using actual emissions 
data, as shown in Table 1 of this preamble, indicate that no 
carcinogens are emitted by this category. Therefore, the cancer MIR 
based on actual emissions (lifetime) is zero and the total estimated 
annual cancer incidence (national) from these facilities based on 
actual emission levels is zero excess cancer cases per year. The 
maximum chronic noncancer TOSHI value based on actual emissions is 
0.002 driven by HCl.
---------------------------------------------------------------------------

    \21\ The TOSHI is the sum of the chronic noncancer HQ for 
substances that affect the same target organ or organ system.
    \22\ The maximum estimated acute exposure concentration was 
divided by available short-term threshold values to develop HQ 
values.
---------------------------------------------------------------------------

2. Screening Level Acute Risk Assessment Results
    Table 1 of this preamble shows the acute risk results for the 
Flexible Polyurethane Foam Fabrication source category. The screening 
analysis for acute impacts was based on an emissions multiplier of 10 
for all emissions sources, to estimate the peak emission rates from the 
average rates. The maximum screening acute noncancer HQ value (off-
facility site) is 0.003 driven by HCl. For more detailed acute risk 
screening results, refer to the Flexible Polyurethane Foam Fabrication 
Risk Assessment Report, in the docket for this action.
3. Multipathway Risk Screening Results
    No PB-HAP are emitted from the Flexible Polyurethane Foam 
Fabrication source category, therefore, a multipathway assessment was 
not conducted.
4. Environmental Risk Screening Results
    As described in section III.A of this document, we conducted an 
environmental risk screening assessment for the Flexible Polyurethane 
Foam Fabrication source category for HCl.
    For HCl, the average modeled concentration around each facility 
(i.e., the average concentration of all off-site data points in the 
modeling domain) did not exceed any ecological benchmark. In addition, 
each individual modeled concentration of HCl and HF (i.e., each off-
site data point in the modeling domain) was below the ecological 
benchmarks for all facilities. Based on the results of the 
environmental risk screening analysis, we do not expect an adverse 
environmental effect as a result of HAP emissions from this source 
category.
5. Facility-Wide Risk Results
    As shown in Table 1, the maximum facility-wide cancer MIR is 0.1-
in-1 million, driven by 2,4/2,6-toluene diisocyanate mixture (TDI) 
emissions from a vertical non-category point source and a non-category 
fugitive point source. The total estimated cancer incidence from the 
whole facility is 0.00001 excess cancer cases per year, or one excess 
case in every 100,000 years. No people were estimated to have cancer 
risks above 1-in-1 million from exposure to HAP emitted from both MACT 
and non-MACT sources at the three facilities in this source category. 
The maximum facility-wide TOSHI for the source category is estimated to 
be 0.2, mainly driven by 2,4/2,6-TDI emissions from a vertical non-
category point source and a non-category fugitive point source.
6. What demographic groups might benefit from this regulation?
    To examine the potential for any environmental justice issues that 
might be associated with the Flexible Polyurethane Foam Fabrication 
Operations major source category, we performed a demographic analysis, 
which is an assessment of risks to individual demographic groups of the 
populations living within 5 km and within 50 km of the facilities. In 
the analysis, we evaluated the distribution of HAP-related cancer and 
noncancer risks from the Flexible Polyurethane Foam Fabrication 
Operations major source category across different demographic groups 
within the populations living near facilities.\23\
---------------------------------------------------------------------------

    \23\ Demographic groups included in the analysis are: White, 
African American, Native American, other races and multiracial, 
Hispanic or Latino, children 17 years of age and under, adults 18 to 
64 years of age, adults 65 years of age and over, adults without a 
high school diploma, people living below the poverty level, people 
living two times the poverty level, and linguistically isolated 
people.
---------------------------------------------------------------------------

    Results of the demographic analysis for the source category 
indicate that the minority population is slightly higher within 5 km of 
the three facilities than the national percentage (40 percent versus 38 
percent). This difference is accounted for by the larger African 
American population around the facilities (17 percent versus 12 percent 
nationally). In addition, the percentage of the population living 
within 5 km of facilities in the source category is greater than the 
corresponding national percentage for the demographic groups, ``Ages 0 
to 17'' and ``Below the Poverty Level.'' When examining the risk levels 
of those exposed to emissions from Flexible Polyurethane Foam 
Fabrication facilities, we find that no one is exposed to a cancer risk 
at or above 1-in-1 million or to a chronic noncancer TOSHI greater than 
1. The methodology and the results of the demographic analysis are 
presented in a technical report, Risk and Technology Review--Analysis 
of Demographic Factors for Populations Living Near Flexible 
Polyurethane Foam Fabrication Operations Source Category, September 
2020 (hereafter referred to as the Flexible Polyurethane Foam 
Fabrication Demographic Analysis Report), available in the docket for 
this action.

[[Page 1884]]

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

1. Risk Acceptability
    As noted in section III.A 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 noncancer risk 
ranges, cancer incidence, the maximum noncancer TOSHI, the maximum 
acute noncancer HQ, the extent of noncancer risks, the distribution of 
cancer and noncancer risks in the exposed population, and risk 
estimation uncertainties (54 FR 38044, September 14, 1989).
    For the Flexible Polyurethane Foam Fabrication Operations major 
source category, the risk analysis indicates that there is no cancer 
risk due to actual emissions or allowable emissions. Since there is no 
cancer risk, the risks are considerably less than 100-in-1 million, 
which is the presumptive upper limit of acceptable risk. The risk 
analysis also shows we did not identify a potential for adverse chronic 
noncancer health effects. The acute noncancer risks based on actual 
emissions are low at an HQ of less than 1 (based on the REL) for HCl. 
Therefore, we find there is little potential concern of acute noncancer 
health impacts from actual emissions. In addition, the risk assessment 
indicates no significant potential for multipathway health effects.
    Considering all of the health risk information and factors 
discussed above, including the uncertainties discussed in section 
III.C.7 of this preamble, we propose to find that the risks from the 
Flexible Polyurethane Foam Fabrication source category are acceptable.
2. Ample Margin of Safety Analysis
    We are proposing that the risks from the Flexible Polyurethane Foam 
Fabrication Operations major source category are acceptable. No 
carcinogens are emitted by the Flexible Polyurethane Foam Fabrication 
source category. Therefore, there are no individuals in the exposed 
population with lifetime cancer risks above 1-in-1 million as a result 
of actual or allowable emissions from this category. In addition, the 
maximum chronic noncancer TOSHI value based on actual and allowable 
emissions is well below 1 (0.002 and 0.2, respectively) and the maximum 
screening acute noncancer HQ value (off-facility site) is also well 
below 1 (0.003). Therefore, we are proposing that additional emissions 
controls for flexible polyurethane foam fabrication facilities are not 
necessary to provide an ample margin of safety to protect public 
health.
3. Environmental Effect
    The emissions data for the Flexible Polyurethane Foam Fabrication 
Operations major source category indicate that one environmental HAP is 
emitted by sources within this source category: HCl. The screening-
level evaluation of the potential for adverse environmental effects 
associated with emissions of HCl from the Flexible Polyurethane Foam 
Fabrication source category indicated that each individual 
concentration (i.e., each off-site data point in the modeling domain) 
was below the ecological benchmarks for all facilities. In addition, we 
are unaware of any adverse environmental effects caused by 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.

D. What are the results and proposed decisions based on our technology 
review for the Flexible Polyurethane Foam Fabrication Operations major 
source category and for the Flexible Polyurethane Foam Production and 
Fabrication area source categories?

    As described in section III.B of this preamble, our technology 
review focused on the identification and evaluation of potential 
developments in practices, processes, and control technologies that 
have occurred since the major source and area source NESHAP for 
Flexible Polyurethane Foam Fabrication were promulgated in 2003 and 
2007, respectively. During the technology review we identified existing 
flame laminators as an unregulated process in the major source 
category. This proposal included the establishment of MACT standards 
for that process is described in section IV.A of this preamble. In 
conducting the technology review, we reviewed various information 
sources regarding the emissions from flexible polyurethane foam 
fabrication operations facilities and flexible polyurethane foam 
production facilities. We conducted separate but similar reviews for 
the Flexible Polyurethane Foam major source category and the two area 
source categories. The reviews included a search of the RBLC database, 
reviews of air permits for flexible polyurethane foam fabrication 
operations facilities and flexible polyurethane foam production 
facilities, and a review of emissions standards for similar source 
categories. We reviewed these data sources for information on 
practices, processes, and control technologies that were not considered 
during the development of the Flexible Polyurethane Foam Fabrication 
Operations NESHAP and the Flexible Polyurethane Foam Production and 
Fabrication area source NESHAP. We also looked for information on 
improvements in practices, processes, and control technologies that 
have been employed since development of the NESHAP. Through searches of 
the data sources described in section IV.D of this preamble, one 
development in a practice, process, or control technology was 
identified for loop slitter use in the Flexible Polyurethane Foam 
Fabrication Operations major source category.
    A loop slitter is a large machine used to create thin sheets of 
foam from the large blocks of foam or ``buns'' created at a foam 
production plant. A slitter consists of a large, vertical, oval 
conveyor belt and a cutting mechanism, which cuts a thin sheet of foam 
to the desired thickness. When the buns are mounted on the conveyor of 
the slitter, they are glued end-to-end, forming a loop. Loop slitter 
emissions of HAP can occur from the application of the adhesives used 
to glue the foam buns together if the adhesive used contains HAP. The 
application of the adhesive is performed at the beginning of the loop 
slitting process, which can run for several hours before the bun is 
fully cut and the machine is loaded with new buns of foam.
    At the time of the development of the NESHAP, the EPA found that 
the foam fabrication industry had effectively discontinued the use of 
adhesives containing methylene chloride, which was the primary HAP in 
the adhesives used, and had switched to other adhesives that did not 
contain methylene chloride or other HAP. As a result, for both existing 
and new loop slitters, the MACT standard for loop slitters proposed in 
2001 was the prohibition of HAP-based adhesives. The definition in the 
2001 proposed standards for a HAP-based adhesive was an adhesive 
containing detectable HAP. In comments on the proposed standards, 
industry representatives indicated that the adhesives used contained 
small amounts of HAP rather than the estimated zero HAP content. In 
response to these comments, the definition of HAP-based adhesive was 
revised in the promulgated rule to be an adhesive

[[Page 1885]]

containing 5 percent (by weight) or greater of HAP.
    For new and existing loop slitters, we identified a potential 
development in existing practices and control techniques not currently 
required by the Flexible Polyurethane Foam Fabrication Operations MACT 
standards. Through the review of other air toxics MACT standards, we 
noted that several other NESHAP, developed both before and after the 
Flexible Polyurethane Foam Fabrication Operations NESHAP, include a 
definition of non-HAP adhesive or coating (where the coating definition 
included adhesives) with a lower percentage of HAP content than that of 
the definition included in the Flexible Polyurethane Foam Fabrication 
Operations rule.
    Additionally, through review of SDS provided by industry, we found 
that the current adhesives used in loop slitting operations are less 
than 1-percent HAP content by total weight. Based on the current 
industry standards of adhesive usage containing less than 1-percent HAP 
and the definition for HAP-based adhesive from similar source 
categories regulating adhesives, we are proposing to revise the 
definition of ``HAP-based adhesive'' to read: ``an adhesive containing 
1 percent (by weight) or more of HAP, according to EPA Method 311 
(appendix A to 40 CFR part 63) or another approved alternative.'' This 
lowering of the total HAP weight of an adhesive from 5 percent to 1 
percent is not expected to yield any reductions in emissions but will 
codify current industry practices and prevent backsliding.
    We propose to amend 40 CFR 63.8802(a)(1)(i) and (a)(3)(i), which 
describe how to determine the mass fraction of HAP in each material 
used, to remove references to Occupational Safety and Health 
Administration (OSHA)-defined carcinogens as specified in 29 CFR 
1910.1200(d)(4). The reference to OSHA-defined carcinogens as specified 
in 29 CFR 1910.1200(d)(4) was intended to specify which compounds must 
be included in calculating total HAP content of a coating material if 
they are present at 0.1-percent or greater by mass. We are proposing to 
remove these references because 29 CFR 1910.1200(d)(4) has been amended 
and no longer readily defines which compounds are carcinogens. We are 
proposing to replace these references to OSHA-defined carcinogens and 
29 CFR 1910.1200(d)(4) with a list (in proposed new Table 8 to 40 CFR 
part 63, subpart MMMMM) of those HAP that must be included in 
calculating total HAP content of a coating material if they are present 
at 0.1 percent or greater by mass.
    We propose to include HAP in proposed Table 8 to 40 CFR part 63, 
subpart MMMMM if they were categorized in the EPA's Prioritized Chronic 
Dose-Response Values for Screening Risk Assessments (May 9, 2014), as a 
``human carcinogen,'' ``probable human carcinogen,'' or ``possible 
human carcinogen'' according to The Risk Assessment Guidelines of 1986 
(EPA/600/8-87/045, August 1987),\24\ or as ``carcinogenic to humans,'' 
``likely to be carcinogenic to humans,'' or with ``suggestive evidence 
of carcinogenic potential'' according to the Guidelines for Carcinogen 
Risk Assessment (EPA/630/P-03/001F, March 2005).\25\
---------------------------------------------------------------------------

    \24\ See https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants.
    \25\ See https://www.epa.gov/risk/guidelines-carcinogen-risk-assessment.
---------------------------------------------------------------------------

    For the Flexible Polyurethane Foam Production and Flexible 
Polyurethane Foam Fabrication area source categories, we find that 
there are no additional emissions of the listed urban HAP methylene 
chloride. As noted in section II.B of this document, methylene chloride 
is no longer used within either source category. Additionally, we did 
not find any advances in technologies during our review of the source 
categories. Detailed information of the technology review can be found 
in the memorandum titled Technology Review for the Flexible 
Polyurethane Foam Production and Fabrication Area Source Categories, 
which is available in the docket for this proposed rule (Docket ID No. 
EPA-HQ-OAR-2020-0572).

E. What other actions are we proposing?

    In addition to the proposed actions described above, we are 
proposing additional revisions to the NESHAP. We are proposing 
revisions to the SSM provisions of the MACT rule in order to ensure 
that they are consistent with the decision in Sierra Club v. EPA, 551 
F. 3d 1019 (D.C. Cir. 2008), in which the court vacated two provisions 
that exempted sources from the requirement to comply with otherwise 
applicable CAA section 112(d) emission standards during periods of SSM. 
We also are proposing various other changes to reporting and 
recordkeeping requirements and to periodic testing requirements. Our 
analyses and proposed changes related to these issues are discussed 
below.
    In its 2008 decision in Sierra Club v. EPA, 551 F.3d 1019 (D.C. 
Cir. 2008), the court vacated portions of two provisions in the EPA's 
CAA section 112 regulations governing the emissions of HAP during 
periods of SSM. 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 CAA section 112 standards apply 
continuously.
    We are proposing the elimination of SSM exemptions in this rule, 
including any reference to requirements included in 40 CFR part 63, 
subpart A (General Provisions). Consistent with Sierra Club v. EPA, we 
are proposing standards in this rule that apply at all times. We are 
also proposing several revisions to Table 7 to 40 CFR part 63, subpart 
MMMMM, as is explained in more detail below. For example, we are 
proposing to eliminate the incorporation of the General Provisions' 
requirement that each source develop an SSM plan. 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.
    Periods of startup, normal operations, and shutdown are all 
predictable and routine aspects of a source's operations. Malfunctions, 
in contrast, are neither predictable nor routine. Instead, they are, by 
definition, sudden, infrequent, and not reasonably preventable failures 
of an emissions control, process, or monitoring equipment. (40 CFR 
63.2, Definition of malfunction). The EPA interprets CAA section 112 as 
not requiring emissions that occur during periods of malfunction to be 
factored into development of CAA section 112 standards, and this 
reading has been upheld as reasonable by the court. See U.S. Sugar 
Corp. v. EPA, 830 F.3d 579, 606-610 (2016). 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

[[Page 1886]]

category. There is nothing in CAA section 112 that directs the Agency 
to consider malfunctions in determining the level ``achieved'' by the 
best performing sources when setting emission standards. The court has 
recognized that the phrase ``average emissions limitation achieved by 
the best performing 12 percent of'' sources ``says nothing about how 
the performance of the best units is to be calculated.'' Nat'l Ass'n of 
Clean Water Agencies v. EPA, 734 F.3d 1115, 1141 (D.C. Cir. 2013). 
While the EPA accounts for variability in setting emissions standards, 
nothing in CAA section 112 requires the Agency to consider malfunctions 
as part of that analysis. The EPA is not required to treat a 
malfunction in the same manner as the type of variation in performance 
that occurs during routine operations of a source. A malfunction is a 
failure of the source to perform in a ``normal or usual manner'' and no 
statutory language compels the EPA to consider such events in setting 
CAA section 112 standards.
    As the court recognized in U.S. Sugar Corp., accounting for 
malfunctions in setting standards would be difficult, if not 
impossible, given the myriad 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. U.S. Sugar Corp. at 
608 (``The EPA would have to conceive of a standard that could apply 
equally to the wide range of possible boiler malfunctions, ranging from 
an explosion to minor mechanical defects. Any possible standard is 
likely to be hopelessly generic to govern such a wide array of 
circumstances.''). As such, the performance of units that are 
malfunctioning is not ``reasonably'' foreseeable. See, e.g., 
Weyerhaeuser Co. v. Costle, 590 F.2d 1011, 1058 (D.C. Cir. 1978) (``In 
the nature of things, no general limit, individual permit, or even any 
upset provision can anticipate all upset situations. After a certain 
point, the transgression of regulatory limits caused by `uncontrollable 
acts of third parties,' such as strikes, sabotage, operator 
intoxication or insanity, and a variety of other eventualities, must be 
a matter for the administrative exercise of case-by-case enforcement 
discretion, not for specification in advance by regulation.'').
    Moreover, emissions during a malfunction event can be significantly 
higher than emissions at any other time of source operation. For 
example, if an air pollution control device with 99-percent removal 
goes off-line as a result of a malfunction (as might happen if, for 
example, the bags in a baghouse catch fire) and the emission unit is a 
steady state-type unit that would take days to shut down, the source 
would go from 99-percent control to zero control until the control 
device was repaired. The source's emissions during the malfunction 
would be 100 times higher than during normal operations. As such, the 
emissions over a 4-day malfunction period would exceed the annual 
emissions of the source during normal operations. As this example 
illustrates, accounting for malfunctions could lead to standards that 
are not reflective of (and are significantly less stringent than) 
levels that are achieved by a well-performing non-malfunctioning 
source. It is reasonable to interpret CAA section 112 to avoid such a 
result. The EPA's approach to malfunctions is consistent with CAA 
section 112 and is a reasonable interpretation of the statute.
    Although no statutory language compels the EPA to set standards for 
malfunctions, the EPA has the discretion to do so where feasible. For 
example, in the Petroleum Refinery Sector RTR, the EPA established a 
work practice standard for unique types of malfunction that result in 
releases from pressure relief devices or emergency flaring events 
because the EPA had information to determine that such work practices 
reflected the level of control that applies to the best performers. 80 
FR 75178, 75211 through 14 (December 1, 2015). The EPA considers 
whether circumstances warrant setting standards for a particular type 
of malfunction and, if so, whether the EPA has sufficient information 
to identify the relevant best-performing sources and establish a 
standard for such malfunctions. We also encourage commenters to provide 
any such information.
    In the event that a source fails to comply with the applicable CAA 
section 112(d) standards as a result of a malfunction event, the EPA 
would determine an appropriate response based on, among other things, 
the good faith efforts of the source to minimize emissions during 
malfunction periods, including preventative and corrective actions, as 
well as root cause analyses to ascertain and rectify excess emissions. 
The EPA would also consider whether the source's failure to comply with 
the CAA section 112(d) standard was, in fact, sudden, infrequent, not 
reasonably preventable, and was not instead caused, in part, by poor 
maintenance or careless operation. 40 CFR 63.2 (Definition of 
malfunction).
    If the EPA determines in a particular case that an enforcement 
action against a source for violation of an emission standard is 
warranted, the source can raise any and all defenses in that 
enforcement action and the federal district court will determine what, 
if any, relief is appropriate. The same is true for citizen enforcement 
actions. Similarly, the presiding officer in an administrative 
proceeding can consider any defense raised and determine whether 
administrative penalties are appropriate.
    In summary, the EPA interpretation of the CAA and, in particular, 
CAA section 112 is reasonable and encourages practices that will avoid 
malfunctions. Administrative and judicial procedures for addressing 
exceedances of the standards fully recognize that violations may occur 
despite good faith efforts to comply and can accommodate those 
situations. See U.S. Sugar Corp., 830 F.3d at 606-610. Therefore, we 
are proposing to change the requirements for SSM by removing the 
exemption for new flame laminators from the requirements to meet the 
standard during SSM periods and by removing the requirement to develop 
and implement an SSM plan. The EPA is proposing revisions to Table 7 of 
subpart MMMMM, The Applicability of General Provisions, to remove SSM 
exemptions and plan development for new flame lamination sources.
    Electronic reporting. The EPA is proposing that owners or operators 
of flexible polyurethane foam fabrication operations facilities submit 
electronic copies of required performance test reports, performance 
evaluation reports, and periodic reports through the EPA's Central Data 
Exchange (CDX) using the Compliance and Emissions Data Reporting 
Interface (CEDRI). A description of the electronic data submission 
process is provided in the memorandum, Electronic Reporting 
Requirements for New Source Performance Standards (NSPS) and National 
Emission Standards for Hazardous Air Pollutants (NESHAP) Rules, 
available in the docket for this action. The proposed rule requires 
that performance test results collected using test methods that are 
supported by the EPA's Electronic Reporting Tool (ERT) as listed on the 
ERT website \26\ at the time of the test be submitted in the format 
generated through the use of the ERT or an electronic file consistent 
with the xml schema on the ERT website, and other performance test 
results be submitted in portable document format (PDF) using the 
attachment module of the ERT. The proposed rule requires that 
Notification of Compliance Status

[[Page 1887]]

reports be submitted as a PDF upload in CEDRI.
---------------------------------------------------------------------------

    \26\ https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert.
---------------------------------------------------------------------------

    For performance test reports, performance evaluation reports, and 
periodic reports, the proposed rule requires that owners or operators 
use the appropriate spreadsheet template to submit information to 
CEDRI. A draft version of the proposed template(s) for these reports is 
included in the docket for this action.\27\ The EPA specifically 
requests comment on the content, layout, and overall design of the 
template(s).
---------------------------------------------------------------------------

    \27\ See Flexible Foam Fabrication ERT templates, available at 
Docket ID. No. EPA-HQ-OAR-2020-0572.
---------------------------------------------------------------------------

    Additionally, the EPA has identified two broad circumstances in 
which electronic reporting extensions may be provided. These 
circumstances are (1) outages of the EPA's CDX or CEDRI which preclude 
an owner or operator from accessing the system and submitting required 
reports and (2) force majeure events, which are defined as events that 
will be or have been caused by circumstances beyond the control of the 
affected facility, its contractors, or any entity controlled by the 
affected facility that prevent an owner or operator from complying with 
the requirement to submit a report electronically. Examples of force 
majeure events are acts of nature, acts of war or terrorism, or 
equipment failure or safety hazards beyond the control of the facility. 
The EPA is providing these potential extensions to protect owners or 
operators from noncompliance in cases where they cannot successfully 
submit a report by the reporting deadline for reasons outside of their 
control. In both circumstances, the decision to accept the claim of 
needing additional time to report is within the discretion of the 
Administrator, and reporting should occur as soon as possible.
    The electronic submittal of the reports addressed in this proposed 
rulemaking will increase the usefulness of the data contained in those 
reports, is in keeping with current trends in data availability and 
transparency, will further assist in the protection of public health 
and the environment, will improve compliance by facilitating the 
ability of regulated facilities to demonstrate compliance with 
requirements, and by facilitating the ability of delegated state, 
local, tribal, and territorial air agencies and the EPA to assess and 
determine compliance, and will ultimately reduce burden on regulated 
facilities, delegated air agencies, and the EPA. Electronic reporting 
also eliminates paper-based, manual processes, thereby saving time and 
resources, simplifying data entry, eliminating redundancies, minimizing 
data reporting errors, and providing data quickly and accurately to the 
affected facilities, air agencies, the EPA, and the public. Moreover, 
electronic reporting is consistent with the EPA's plan \28\ to 
implement Executive Order 13563 and is in keeping with the EPA's 
Agency-wide policy \29\ developed in response to the White House's 
Digital Government Strategy.\30\ For more information on the benefits 
of electronic reporting, see the memorandum, Electronic Reporting 
Requirements for New Source Performance Standards (NSPS) and National 
Emission Standards for Hazardous Air Pollutants (NESHAP) Rules, 
referenced earlier in this section.
---------------------------------------------------------------------------

    \28\ The EPA's Final Plan for Periodic Retrospective Reviews, 
August 2011. Available at: https://www.regulations.gov/document?D=EPA-HQ-OA-2011-0156-0154.
    \29\ E-Reporting Policy Statement for EPA Regulations, September 
2013. Available at https://www.epa.gov/sites/production/files/2016-03/documents/epa-ereporting-policy-statement-2013-09-30.pdf.
    \30\ Digital Government: Building a 21st Century Platform to 
Better Serve the American People, May 2012. Available at https://obamawhitehouse.archives.gov/sites/default/files/omb/egov/digital-government/digital-government.html.
---------------------------------------------------------------------------

F. What compliance dates are we proposing?

    The EPA is proposing that affected sources that commenced 
construction or reconstruction on or before January 11, 2021, must 
comply with all of the amendments, with the exception of the proposed 
electronic format for submitting notifications and compliance reports, 
no later than 180 days after the effective date of the final rule, or 
upon startup, whichever is later. Affected sources that commence 
construction or reconstruction after January 11, 2021, must comply with 
all requirements of the subpart, including the amendments being 
proposed, with the exception of the proposed electronic format for 
submitting notifications and compliance reports, no later than the 
effective date of the final rule or upon startup, whichever is later. 
All affected facilities would have to continue to meet the current 
requirements of 40 CFR part 63, subpart MMMMM, until the applicable 
compliance date of the amended rule. The final action is not expected 
to be a ``major rule'' as defined by 5 U.S.C. 804(2), so the effective 
date of the final rule will be the promulgation date as specified in 
CAA section 112(d)(10).
    For existing sources, we are proposing four changes that would 
impact ongoing compliance requirements for 40 CFR part 63, subpart 
MMMMM. As discussed elsewhere in this preamble, we are proposing to add 
numeric limits for HCl emissions from existing flame laminators. We are 
also proposing a requirement that notifications, performance test 
results, and compliance reports be submitted electronically.
    Our experience with similar industries that are required to convert 
reporting mechanisms to install necessary hardware and software, become 
familiar with the process of submitting performance test results 
electronically through the EPA's CEDRI, test these new electronic 
submission capabilities, and reliably employ electronic reporting shows 
that a time period of a minimum of 90 days, and, more typically, 180 
days, is generally necessary to accomplish these revisions. For the 
proposed SSM revisions, we recognize that there are no facilities that 
are currently using the SSM provisions for new flame laminators, since 
there have not been any new sources since the standard was promulgated. 
As a result, we do not believe that any additional time is needed for 
compliance with the revised SSM provisions.
    We have consulted with the regulated industry regarding the 
proposed limits for existing flame laminators, and the requirement to 
conduct performance testing to demonstrate initial compliance within 
180 days of the publication of the final rule and no less than every 5 
years thereafter, to better understand the likely implications of the 
proposed revisions. There are two impacted facilities, owned by one 
parent company, and representatives from that company have indicated 
that performance testing could be done within the proposed time frame 
for compliance. For the proposed limit for existing sources, we believe 
that the two facilities that would be subject to the standards are able 
to meet the limit without add-on controls. However, we do recognize 
that facilities will need time to conduct performance tests and 
demonstrate compliance with the proposed emission limit.
    The EPA recognizes the confusion that multiple and different 
compliance dates for individual requirements would create and the 
additional burden such an assortment of dates would impose. From our 
assessment of the timeframe needed for compliance with the entirety of 
the revised requirements, the EPA considers a period of 180 days to be 
the most expeditious compliance period practicable and is, thus, 
proposing that all affected sources that commenced construction or 
reconstruction on or before January 11, 2021, be in compliance with all 
of this regulation's

[[Page 1888]]

revised requirements within 180 days of the regulation's effective 
date, with the exception of the electronic reporting requirements.
    We solicit comment on the proposed compliance periods, and we 
specifically request submission of information from sources in this 
source category regarding specific actions that would need to be 
undertaken to comply with the proposed amended requirements and the 
time needed to make the adjustments for compliance with any of the 
revised requirements. We note that information provided may result in 
changes to the proposed compliance dates.

V. Summary of Cost, Environmental, and Economic Impacts

A. What are the affected sources?

    Currently, three major sources subject to the Flexible Polyurethane 
Foam Fabrication Operations NESHAP are operating in the United States. 
The affected sources under the NESHAP include flexible polyurethane 
foam fabrication plant sites that operate loop slitters and/or flame 
laminators. Facilities that use loop slitter adhesive processes would 
be required to comply with a ban on the use of adhesives containing air 
toxics. However, the EPA estimates that current air toxic emissions 
from loop slitter adhesive users are essentially zero as the result of 
changes in adhesive composition required by OSHA's permissible exposure 
limit for methylene chloride prior to the promulgation of the original 
MACT standard. Additionally, the EPA estimates that current air toxic 
emissions from flame laminators for the entire source category are less 
than 3.5 tpy.
    Currently, there are approximately 32 area sources subject to the 
Flexible Polyurethane Foam Production and Fabrication NESHAP. The area 
source standard only regulates methylene chloride emissions and, 
similar to the major source standards, emissions of methylene chloride 
are essentially zero as required by OSHA's permissible exposure limit 
for methylene chloride prior to the promulgation of the original GACT 
standards. Based on information provided by industry, there are no 
emissions of methylene chloride from these sources. For detailed 
information please see the memorandum titled Technology Review for the 
Flexible Polyurethane Foam Production and Fabrication Area Source 
Categories, located in the docket for this action.

B. What are the air quality impacts?

    Current estimated emissions from the Flexible Polyurethane Foam 
Fabrication Operations source category are approximately 3.5 tpy. We do 
not estimate any HAP emission reductions from the proposed requirement 
for MACT limits for existing flame laminators nor from the proposed 
revision to the definition of HAP-based adhesives for loop slitters. 
Both proposed revisions reflect current practices.

C. What are the cost impacts?

    The proposed revisions to the Flexible Polyurethane Foam 
Fabrication Operations NESHAP for major sources are expected to have 
minimal cost impacts. The costs are associated with periodic emissions 
performance testing, electronic reporting, and reviewing the proposed 
rule. Three major source facilities are affected by these costs. The 
one-time cost associated with reviewing the proposed rule and becoming 
familiar with the electronic reporting system is estimated to be $2,200 
per facility in 2019 dollars. The EPA estimates the cost of the HCl 
emissions testing requirement to be $12,000 per test. This test is 
required every 5 years. Prior to the initial test, installation and 
calibration of equipment is required which costs an estimated $3,200. 
The total cost per facility in Year 1 is estimated to be $17,300, and 
subsequent costs are estimated to be $12,000 every 5 years thereafter.

D. What are the economic impacts?

    The proposed revisions to the Flexible Polyurethane Foam 
Fabrication Operations NESHAP for major sources and the Flexible 
Polyurethane Foam Production and Fabrication NESHAP for area sources 
are not expected to have market impacts. Over a 10-year timeframe from 
2021 to 2030, the net present value of the estimated cost impacts is 
$83,000 at a 3-percent discount rate and $77,600 at a 7-percent 
discount rate in 2019 dollars. The equivalent annualized value of the 
cost impacts is $9,700 at a 3-percent discount rate and $11,000 at a 7-
percent discount rate. Since the costs associated with the proposed 
rule are minimal, no significant economic impacts are anticipated due 
to the proposed revisions. See the memorandum titled Economics Memo 
Flex Foam NESHAP Proposal, in the docket for discussion of the 
facility-level cost estimates as well as the net present value and 
equivalent annualized value estimates.

E. What are the benefits?

    Although the EPA does not anticipate any significant reductions in 
HAP emissions as a result of the proposed amendments, the action, if 
finalized as proposed, would result in improvements to the rule and 
prevent backsliding. Specifically, the proposed amendments codify 
existing industry practices both for existing flame laminators and for 
new and existing sources of adhesives used with loop slitters. The 
proposed revisions also amend the standards such that they apply at all 
times. Additionally, the proposed amendments requiring electronic 
submittal of initial notifications, performance test results, and 
semiannual reports will increase the usefulness of the data, are in 
keeping with current trends of data availability, will further assist 
in the protection of public health and the environment, and will 
ultimately result in less burden on the regulated community. See 
section IV.E of this preamble for more information.

VI. Request for Comments

    We solicit comments on 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 for 
download on the RTR website at https://www.epa.gov/stationary-sources-air-pollution/flexible-polyurethane-foam-fabrication-operations-national-emission. 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

[[Page 1889]]

downloaded from the RTR website, complete the following steps:
    1. Within this downloaded file, enter suggested 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 emission revisions (e.g., 
performance test reports, material balance calculations).
    4. Send the entire downloaded file with suggested revisions in 
Microsoft[reg] Access format and all accompanying documentation to 
Docket ID No. EPA-HQ-OAR-2020-0572 (through the method described in the 
ADDRESS section of this preamble).
    5. If you are providing comments on a single facility or mulitiple 
facilities, you need only submit one file for all facilities. The file 
should contain all suggested for all sources at the facility (or 
facilities). We request that all data revision comments be submitted in 
the form of updated Microsoft[reg] Excel files that are generated by 
the Microsoft[reg] Access file. These files are provided on the project 
website at https://www.epa.gov/stationary-sources-air-pollution/flexible-polyurethane-foam-fabrication-operations-national-emission.

VIII. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders 
can be found at https://www.epa.gov/laws-regulations/laws-and-executive-orders.

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

    This action is not a significant regulatory action and was, 
therefore, not submitted to OMB for review.

B. Executive Order 13771: Reducing Regulations and Controlling 
Regulatory Costs

    This action is not expected to be an Executive Order 13771 
regulatory action because this action is not significant under 
Executive Order 12866.

C. Paperwork Reduction Act (PRA)

    The information collection activities in this proposed rule have 
been submitted for approval to OMB under the PRA. The Information 
Collection Request (ICR) document that the EPA prepared has been 
assigned EPA ICR number 2027.08. You can find a copy of the ICR in the 
docket for this rule, and it is briefly summarized here. The ICR is 
specific to information collection associated with the Flexible 
Polyurethane Foam Fabrication Operations source category, through 
amendments to 40 CFR part 63, subpart MMMMM. (The subject rulemaking 
imposes no new information collection associated with either the 
Flexible Polyurethane Foam Production area source category or the 
Flexible Polyurethane Foam Fabrication area source category.) We are 
proposing changes to the recordkeeping and reporting requirements 
associated with 40 CFR part 63, subpart MMMMM, in the form of: 
Requiring periodic (every 5 years) performance tests at major sources; 
eliminating the SSM plan and reporting requirements; including 
reporting requirements for deviations in the semiannual report; and 
including the requirement for electronic submittal of reports. In 
addition, the number of facilities subject to the standards changed. 
The number of respondents was reduced from 20 to 3 based on 
consultation with industry representatives and state/local agencies.
    Respondents/affected entities: The respondents to the recordkeeping 
and reporting requirements are owners or operators of flexible 
polyurethane foam fabrication operations subject to 40 CFR part 63, 
subpart MMMMM.
    Respondent's obligation to respond: Mandatory (40 CFR part 63, 
subpart MMMMM).
    Estimated number of respondents: 3 facilities.
    Frequency of response: The frequency of responses varies depending 
on the burden item. Responses include one-time review of rule 
amendments, reports of periodic performance tests, and semiannual 
compliance reports.
    Total estimated burden: The annual recordkeeping and reporting 
burden for responding facilities to comply with all of the requirements 
in the NESHAP, averaged over the 3 years of this ICR, is estimated to 
be 148 hours (per year). The average annual burden to the Agency over 
the 3 years after the amendments are final is estimated to be 51 hours 
(per year) for the Agency. Burden is defined at 5 CFR 1320.3(b).
    Total estimated cost: The annual recordkeeping and reporting cost 
for responding facilities to comply with all of the requirements in the 
NESHAP, averaged over the 3 years of this ICR, is estimated to be 
$15,000 (rounded, per year). There are no estimated capital and 
operation and maintenance costs. The total average annual Agency cost 
over the first 3 years after the amendments are final is estimated to 
be $2,500.
    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.
    Submit your comments on the Agency's need for this information, the 
accuracy of the provided burden estimates, and any suggested methods 
for minimizing respondent burden to the EPA using the docket identified 
at the beginning of this rule. You may also send your ICR-related 
comments to OMB's Office of Information and Regulatory Affairs via 
email to [email protected], Attention: Desk Officer for the 
EPA. Since OMB is required to make a decision concerning the ICR 
between 30 and 60 days after receipt, OMB must receive comments no 
later than February 10, 2021. The EPA will respond to any ICR-related 
comments in the final rule.

D. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. In 
making this determination, the impact of concern is any significant 
adverse economic impact on small entities. An agency may certify that a 
rule will not have a significant economic impact on a substantial 
number of small entities if the rule relieves regulatory burden, has no 
net burden, or otherwise has a positive economic effect on the small 
entities subject to the rule. As proposed, this action would 
potentially impose new requirements only on major sources, and none of 
the major sources in the Flexible Polyurethane Foam Fabrication 
Operations source category are considered a small entity. We have, 
therefore, concluded that this action will have no net regulatory 
burden for all directly regulated small entities.

E. Unfunded Mandates Reform Act (UMRA)

    This action does not contain an unfunded mandate of $100 million or 
more as described in UMRA, 2 U.S.C. 1531-1538, and does not 
significantly or uniquely affect small governments. The action imposes 
no enforceable duty on any state, local, or tribal governments or the 
private sector.

F. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national

[[Page 1890]]

government and the states, or on the distribution of power and 
responsibilities among the various levels of government.

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

    This action does not have tribal implications as specified in 
Executive Order 13175. No tribal facilities are known to be engaged in 
the industries that would be affected by this action nor are there any 
adverse health or environmental effects from this action. Thus, 
Executive Order 13175 does not apply to this action.

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

    This action is not subject to Executive Order 13045 because it is 
not economically significant as defined in Executive Order 12866, and 
because the EPA does not believe the environmental health or safety 
risks addressed by this action present a disproportionate risk to 
children. This action's health and risk assessments are contained in 
sections III.A, IV.B, and IV.C of this preamble.

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

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

J. National Technology Transfer and Advancement Act (NTTAA)

    This rulemaking does not involve technical standards.

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

    The EPA believes that this action does not have disproportionately 
high and adverse human health or environmental effects on minority 
populations, low-income populations, and/or indigenous peoples, as 
specified in Executive Order 12898 (59 FR 7629, February 16, 1994).
    The documentation for this decision is contained in sections IV.B 
and IV.C of this preamble. As discussed in sections IV.B and IV.C of 
this preamble, we performed a demographic analysis for the Flexible 
Polyurethane Foam Fabrication Operations major source category, which 
is an assessment of risks to individual demographic groups, of the 
population close to the facilities (within 50 km and within 5 km). In 
our analysis, we evaluated the distribution of HAP-related cancer risks 
and noncancer hazards from the Flexible Polyurethane Foam Fabrication 
Operations major source category across different social, demographic, 
and economic groups within the populations living near operations 
identified as having the highest risks. Results of the demographic 
analysis performed for the Flexible Polyurethane Foam Fabrication 
Operations major source category indicate that the minority population 
is slightly higher within 5 km of the three facilities than the 
national percentage (40 percent versus 38 percent). This difference is 
accounted for by the larger African American population around the 
facilities (17 percent versus 12 percent nationally). In addition, the 
percentage of the population living within 5 km of facilities in the 
source category is greater than the corresponding national percentage 
for the demographic groups, ``Ages 0 to 17'' and ``Below the Poverty 
Level.'' When examining the risk levels of those exposed to emissions 
from flexible polyurethane foam fabrication facilities, we find that no 
one is exposed to a cancer risk at or above 1-in-1 million or to a 
chronic noncancer TOSHI greater than 1.

List of Subjects in 40 CFR Part 63

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

Andrew Wheeler,
Administrator.
[FR Doc. 2021-00250 Filed 1-8-21; 8:45 am]
BILLING CODE 6560-50-P