[Federal Register Volume 83, Number 177 (Wednesday, September 12, 2018)]
[Proposed Rules]
[Pages 46262-46341]
[FR Doc No: 2018-19018]

Vol. 83

Wednesday,

No. 177

September 12, 2018

Part II

Environmental Protection Agency

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40 CFR Part 63

 National Emission Standards for Hazardous Air Pollutants: Surface
Coating of Large Appliances; Printing, Coating, and Dyeing of Fabrics
and Other Textiles; and Surface Coating of Metal Furniture Residual
Risk and Technology Reviews; Proposed Rule

Federal Register / Vol. 83, No. 177 / Wednesday, September 12, 2018 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2017-0668, EPA-HQ-OAR-2017-0669, EPA-HQ-OAR-2017-0670; FRL-
9982-40-OAR]
RIN 2060-AT72

National Emission Standards for Hazardous Air Pollutants: Surface
Coating of Large Appliances; Printing, Coating, and Dyeing of Fabrics
and Other Textiles; and Surface Coating of Metal Furniture Residual
Risk and Technology Reviews

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing the
results of the residual risk and technology reviews (RTR) for three
rules--the National Emission Standards for Hazardous Air Pollutants
(NESHAP) for the Surface Coating of Large Appliances; the NESHAP for
the Printing, Coating, and Dyeing of Fabrics and Other Textiles; and
the NESHAP for the Surface Coating of Metal Furniture. The EPA is
proposing to find the risks due to emissions of air toxics from these
source categories under the current standards to be acceptable and that
the standards provide an ample margin of safety to protect public
health. We are proposing no revisions to the numerical emission limits
based on these risk analyses or technology reviews. The EPA is
proposing no new requirements based on the technology review of the
NESHAP for the Printing, Coating, and Dyeing of Fabrics and Other
Textiles. The EPA is proposing to require the use of high efficiency
spray application equipment under the technology review for the two
rules that employ the use of coating spray application, the NESHAP for
the Surface Coating of Large Appliances and the NESHAP for the Surface
Coating of Metal Furniture, if the source is not using the emission
rate with add-on control compliance option. The EPA is also requesting
comment on whether the high efficiency spray equipment technology
requirement under the technology review is necessary in light of the
risk analyses indicating that there are ample margins of safety. The
EPA also is proposing to amend provisions addressing emissions during
periods of startup, shutdown, and malfunction; to amend provisions
regarding electronic reporting of performance test results; and to make
miscellaneous clarifying and technical corrections.

DATES:
    Comments. Comments must be received on or before October 29, 2018.
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 October 12, 2018.
    Public Hearing. If a public hearing is requested by September 17,
2018, we will hold a hearing. Additional information about the hearing,
if requested, will be published in a subsequent Federal Register
document and posted at https://www.epa.gov/stationary-sources-air-pollution/printing-coating-and-dyeing-fabrics-and-other-textiles-national, https://www.epa.gov/stationary-sources-air-pollution/surface-coating-large-appliances-national-emission-standards, and https://www.epa.gov/stationary-sources-air-pollution/surface-coating-metal-furniture-national-emission-standards. See SUPPLEMENTARY INFORMATION
for information on requesting and registering for a public hearing.

ADDRESSES:
    Comments. Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2017-0668 for 40 Code of Federal Regulations (CFR) part 63, subpart
OOOO, Printing, Coating, and Dyeing of Fabrics and Other Textiles;
Docket ID No. EPA-HQ-OAR-2017-0669 for 40 CFR part 63, subpart RRRR,
Surface Coating of Metal Furniture; or Docket ID No. EPA-HQ-OAR-2017-
0670 for 40 CFR part 63, subpart NNNN, Surface Coating of Large
Appliances, as applicable, at https://www.regulations.gov. Follow the
online instructions for submitting comments. Once submitted, comments
cannot be edited or removed from Regulations.gov. Regulations.gov is
our preferred method of receiving comments. However, other submission
methods are accepted. To ship or send mail via the United States Postal
Service, use the following address: U.S. Environmental Protection
Agency, EPA Docket Center, Docket ID Nos. EPA-HQ-OAR-2017-0668, EPA-HQ-
OAR-2017-0669, or EPA-HQ-OAR-2017-0670 (specify the applicable docket
number), Mail Code 28221T, 1200 Pennsylvania Avenue NW, Washington, DC
20460. Use the following Docket Center address if you are using express
mail, commercial delivery, hand delivery, or courier: EPA Docket
Center, EPA WJC West Building, Room 3334, 1301 Constitution Avenue NW,
Washington, DC 20004. Delivery verification signatures will be
available only during regular business hours.
    Do not submit electronically any information you consider to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. See section I.C of this preamble
for instructions on submitting CBI. 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.
    Public Hearing. Please contact Ms. Nancy Perry at<PHONE_NUMBER> or
by email at [email protected] to request a public hearing, to
register to speak at the public hearing, or to inquire as to whether a
public hearing will be held.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed
action for the Surface Coating of Large Appliances source category,
contact Ms. Kim Teal, Minerals and Manufacturing Group, Sector Policies
and Programs Division (Mail Code D243-04), Office of Air Quality
Planning and Standards, U.S. Environmental Protection Agency, 109 T.W.
Alexander Dr., Research Triangle Park, North Carolina 27711; telephone
number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>; and email address:
[email protected].
    For questions about this proposed action for the Printing, Coating,
and Dyeing of Fabrics and Other Textiles source category, contact Ms.
Paula Hirtz, Minerals and Manufacturing Group, Sector Policies and
Programs Division (Mail Code D243-04), Office of Air Quality Planning
and Standards, U.S. Environmental Protection Agency, 109 T.W. Alexander
Dr., Research Triangle Park, North Carolina 27711; telephone number:
(919) 541-2618; fax number:<PHONE_NUMBER>; and email address:
[email protected].
    For questions about this proposed action for the Surface Coating of
Metal Furniture source category, contact Ms. J. Kaye Whitfield,
Minerals and Manufacturing Group, Sector Policies and Programs Division
(Mail Code D243-04), Office of Air Quality

Planning and Standards, U.S. Environmental Protection Agency, 109 T.W.
Alexander Dr., Research Triangle Park, North Carolina 27711; telephone
number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>; and email address:
[email protected].
    For specific information regarding the risk modeling methodology,
contact Mr. Chris Sarsony, Health and Environmental Impacts Division
(Mail Code C539-02), Office of Air Quality Planning and Standards, U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina
27711; telephone number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>;
and email address: [email protected].
    For information about the applicability of any of these NESHAP to a
particular entity, contact Mr. John Cox, Office of Enforcement and
Compliance Assurance, U.S. Environmental Protection Agency, EPA WJC
South Building (Mail Code 2227A), 1200 Pennsylvania Avenue NW,
Washington DC 20460; telephone number:<PHONE_NUMBER>; and email
address: [email protected].

SUPPLEMENTARY INFORMATION:
    Docket. The EPA has established three separate dockets for this
rulemaking. Docket ID No. EPA-HQ-OAR-2017-0668 has been established for
40 CFR part 63, subpart OOOO, Printing, Coating, and Dyeing of Fabrics
and Other Textiles (hereafter referred to as the Fabrics and Other
Textiles Docket). Docket ID No. EPA-HQ-OAR-2017-0669 has been
established for 40 CFR part 63, subpart RRRR, Surface Coating of Metal
Furniture (hereafter referred to as the Metal Furniture Docket). Docket
ID No. EPA-HQ-OAR-2017-0670 has been established for 40 CFR part 63,
subpart NNNN, Surface Coating of Large Appliances (hereafter referred
to as the Large Appliances Docket). All documents in the dockets are
listed in Regulations.gov. Although listed, some information is not
publicly available, e.g., CBI or other information whose disclosure is
restricted by statute. Certain other material, such as copyrighted
material, is not placed on the internet and will be publicly available
only in hard copy. Publicly available docket materials are available
either electronically in Regulations.gov or in hard copy at the EPA
Docket Center, Room 3334, EPA WJC West Building, 1301 Constitution
Avenue NW, Washington, DC. The Public Reading Room is open from 8:30
a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The
telephone number for the Public Reading Room is<PHONE_NUMBER>, and the
telephone number for the EPA Docket Center is<PHONE_NUMBER>.
    Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2017-0668 for 40 CFR part 63, subpart OOOO, Printing, Coating, and
Dyeing of Fabrics and Other Textiles; Docket ID No. EPA-HQ-OAR-2017-
0669 for 40 CFR part 63, subpart RRRR, Surface Coating of Metal
Furniture; or Docket ID No. EPA-HQ-OAR-2017-0670 for 40 CFR part 63,
subpart NNNN, Surface Coating of Large Appliances, as applicable to
your comments. 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 information that you consider to be CBI or
otherwise protected through https://www.regulations.gov or email. This
type of information should be submitted by mail as discussed in the
ADDRESSES section and section I.C of this preamble. The https://www.regulations.gov website allows you to submit your comments
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.
    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:

ACA American Coatings Association
AEGL acute exposure guideline level
AERMOD air dispersion model used by the HEM-3 model
BACT best available control technology
CAA Clean Air Act
CalEPA California EPA
CBI Confidential Business Information
CFR Code of Federal Regulations
ECHO Enforcement and Compliance History Online
EPA Environmental Protection Agency
ERPG Emergency Response Planning Guideline
ERT Electronic Reporting Tool
GACT generally available control technology
gal gallon
HAP hazardous air pollutant(s)
HCl hydrochloric acid
HEM-3 Human Exposure Model, Version 1.1.0
HF hydrogen fluoride
HI hazard index
HQ hazard quotient
IBR incorporation by reference
ICAC Institute of Clean Air Companies
IRIS Integrated Risk Information System
kg kilogram
km kilometer
LAER lowest achievable emission rate
lb pound
MACT maximum achievable control technology
mg/kg-day milligrams per kilogram per day
mg/m\3\ milligrams per cubic meter
MIR maximum individual risk
NAAQS National Ambient Air Quality Standards
NAICS North American Industry Classification System
NEI National Emission Inventory
NESHAP national emission standards for hazardous air pollutants
NSR New Source Review
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
OSHA Occupational Safety and Health Administration
PB-HAP hazardous air pollutants known to be persistent and bio-
accumulative in the environment
PDF portable document format
ppmv parts per million by volume
ppmw parts per million by weight
PTE permanent total enclosure
RACT reasonably available control technology
REL reference exposure level
RFA Regulatory Flexibility Act
RfC reference concentration
RfD reference dose
RTO regenerative thermal oxidizer
RTR residual risk and technology review
SAB Science Advisory Board
SSM startup, shutdown, and malfunction
TOSHI target organ-specific hazard index
tpy tons per year
UF uncertainty factor
UMRA Unfunded Mandates Reform Act
URE unit risk estimate
VCS voluntary consensus standards

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

I. General Information

    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related
information?
    C. What should I consider as I prepare my comments for the EPA?
II. Background
    A. What is the statutory authority for this action?
    B. What 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
    A. How do we consider risk in our decision-making?
    B. How do we perform the technology review?
    C. How did we estimate post-MACT risks posed by these source
categories?
IV. Analytical Results and Proposed Decisions
    A. What are the analytical results and proposed decisions for
the surface coating of large appliances source category?
    B. What are the analytical results and proposed decisions for
the printing, coating, and dyeing of fabrics and other textiles
source category?
    C. What are the analytical results and proposed decisions for
the surface coating of metal furniture source category?
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) and
1 CFR Part 51
    K. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations.

I. General Information

A. Does this action apply to me?

    Table 1 of this preamble lists the NESHAP and associated regulated
industrial source categories that are the subject of this proposal.
Table 1 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. As
defined in the Initial List of Categories of Sources Under Section
112(c)(1) of the Clean Air Act Amendments of 1990 (see 57 FR 31576,
July 16, 1992) and Documentation for Developing the Initial Source
Category List, Final Report (see EPA-450/3-91-030, July 1992), which
provides broad descriptions of the categories of major sources included
on the initial list, the Surface Coating of Large Appliances source
category includes any facility engaged in the surface coating of any
large appliance part or product. The category includes, but is not
limited to, coating of the following large, metal appliance parts or
products: ranges, conventional ovens, microwave ovens, refrigerators,
freezers, washers, dryers, dishwashers, water heaters or trash
compactors manufactured for household, commercial, or recreational use.
Facilities in this source category are also major sources of HAP
emissions. We estimate that 10 major source facilities engaged in large
appliance surface coating would be subject to this proposal. The
Printing, Coating, and Dyeing of Fabrics and Other Textiles source
category includes any facility engaged in those operations. In fabric
printing, a decorative pattern or design is applied to fabric by
methods such as roller, flat screen, or rotary screen. Fabric coating
is an operation that imparts to a textile substrate, additional
properties such as strength, stability, water or acid repellency, or
other specific characteristics of appearance. Fabric dyeing is the
process in which color is added to a substrate. This category includes,
but is not limited to, coating of industrial and electrical tapes, tire
cord, utility meter seals, imitation leathers, tarpaulins, shoe
material, and upholstery fabrics. We estimate that 43 major source
facilities engaged in the printing, coating, and dyeing of fabrics and
other textiles would be subject to this proposal. The Surface Coating
of Metal Furniture source category includes any facility engaged in the
surface coating and manufacture of metal furniture parts or products.
Such products may include chairs, tables, cabinets and bookcases. We
estimate that 16 major source facilities engaged in metal furniture
surface coating would be subject to this proposal.

Table 1--NESHAP and Industrial and Government Source Categories Affected
                         by This Proposed Action
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   NESHAP and source category    NAICS code \1\   Regulated entities \2\
------------------------------------------------------------------------
Surface Coating of Large                 335221  Household cooking
 Appliances.                             335222   equipment.
                                                 Household refrigerators
                                                  and freezers.
                                                 .......................
                                         335224  Household laundry
                                         335228   equipment.
                                                 Other major household
                                                  appliances.
                                         333312  Commercial laundry, dry
                                         333415   cleaning, and pressing
                                                  equipment.
                                                 Air-conditioners
                                                  (except motor
                                                  vehicle), comfort
                                                  furnaces, and
                                                  industrial
                                                  refrigeration units
                                                  and freezers (except
                                                  heat transfer coils
                                                  and large commercial
                                                  and industrial
                                                  chillers).
                                     \3\ 333319  Other commercial/
                                                  service industry
                                                  machinery, e.g.,
                                                  commercial
                                                  dishwashers, ovens,
                                                  and ranges, etc.
Printing, Coating, and Dyeing             31321  Broadwoven fabric
 of Fabrics and Other Textiles.           31322   mills.
                                                 Narrow fabric mills and
                                                  Schiffli machine
                                                  embroidery.
                                         313241  Weft knit fabric mills.
                                         313311  Broadwoven fabric
                                                  finishing mills.
                                         313312  Textile and fabric
                                         313320   finishing (except
                                                  broadwoven fabric)
                                                  mills.
                                                 Fabric coating mills.

                                         314110  Carpet and rug mills.
                                         326220  Rubber and plastics
                                                  hoses and belting and
                                                  manufacturing.
                                         339991  Gasket, packing, and
                                                  sealing device
                                                  manufacturing.
Surface Coating of Metal                 337124  Metal Household
 Furniture.                              337214   Furniture
                                                  Manufacturing.
                                                 Nonwood Office
                                                  Furniture
                                                  Manufacturing.
                                         337127  Institutional Furniture
                                         337215   Manufacturing.
                                                 Showcase, Partition,
                                                  Shelving, and Locker
                                                  Manufacturing.
                                         337127  Institutional Furniture
                                         332951   Manufacturing.
                                                 Hardware Manufacturing.
                                         332116  Metal Stamping.
                                         332612  Wire Spring
                                                  Manufacturing.
                                         337215  Showcase, Partition,
                                         335121   Shelving, and Locker
                                                  Manufacturing.
                                                 Residential Electric
                                                  Lighting Fixture
                                                  Manufacturing.
                                         335122  Commercial, Industrial,
                                                  and Institutional
                                                  Electric Lighting
                                                  Fixture Manufacturing.
                                         339111  Laboratory Furniture
                                                  Manufacturing.
                                         339114  Dental Equipment
                                         337127   Manufacturing.
                                                 Institutional Furniture
                                                  Manufacturing.
                                          81142  Reupholstery and
                                         922140   Furniture Repair
                                                 State correctional
                                                  institutions that
                                                  apply coatings to
                                                  metal furniture.
------------------------------------------------------------------------
\1\ North American Industry Classification System.
\2\ Regulated entities means major source facilities that apply surface
  coatings to these parts or products.
\3\ Excluding special industry machinery, industrial and commercial
  machinery and equipment, and electrical machinery equipment and
  supplies not elsewhere classified.

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

    In addition to being available in the dockets for this action, an
electronic copy of this proposed 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/printing-coating-and-dyeing-fabrics-and-other-textiles-national#rule-summary, https://www.epa.gov/stationary-sources-air-pollution/surface-coating-large-appliances-national-emission-standards,
and https://www.epa.gov/stationary-sources-air-pollution/surface-coating-metal-furniture-national-emission-standards. Following
publication in the Federal Register, the EPA will post the Federal
Register version of the proposal and key technical documents at these
same websites. Information on the overall RTR program is available at
https://www3.epa.gov/ttn/atw/rrisk/rtrpg.html.
    A redline version of the regulatory language that incorporates the
proposed changes in this action is available in the Fabrics and Other
Textiles Docket, Metal Furniture Docket, and Large Appliances Docket.

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

    Submitting CBI. Do not submit information containing CBI to the EPA
through 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 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 CFR part 2. Send or deliver
information identified as CBI only to the following address: OAQPS
Document Control Officer (Mail Code C404-02), OAQPS, U.S. Environmental
Protection Agency, 109 T. W. Alexander Dr., Research Triangle Park,
North Carolina 27711, Attention Docket ID No. EPA-HQ-OAR-2017-0668 for
Printing, Coating, and Dyeing of Fabrics and Other Textiles; Docket ID
No. EPA-HQ-OAR-2017-0669 for Surface Coating of Metal Furniture; or
Docket ID No. EPA-HQ-OAR-2017-0670 for Surface Coating of Large
Appliances, as applicable.

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 Clean Air Act (CAA), as amended (42 U.S.C. 7401 et
seq.).\1\ Section 112 of the CAA establishes a two-stage regulatory
process to develop standards for emissions of hazardous air pollutants
(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 maximum achievable control
technology (MACT) to determine whether additional standards are needed
to further 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
eight years to determine if there are ``developments in practices,
processes, or control technologies'' that may be appropriate to
incorporate into the standards. 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 dockets for each subpart in this
rulemaking.
---------------------------------------------------------------------------

    \1\ In addition, section 301 of the CAA provides general
authority for the Administrator to ``prescribe such regulations as
are necessary to carry out his functions'' under the Act.
---------------------------------------------------------------------------

    In the first stage of the CAA section 112 standard setting process,
the EPA promulgates technology-based standards under CAA section112(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) 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
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.''
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. In certain instances, as
provided in CAA section 112(h), the EPA may set work practice standards
where it is not feasible to prescribe or enforce a numerical emission
standard. 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 according to CAA
section 112(f). Section 112(f)(2) of the CAA requires the EPA to
determine for source categories subject to MACT standards 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 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 (DC 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)
\2\ of approximately [1-in-10 thousand] [i.e., 100-in-1 million].'' 54
FR 38045, September 14, 1989. If risks are unacceptable, the EPA must
determine the emissions standards necessary to bring risks to an
acceptable level without considering costs. In the second step of the
approach, the EPA considers whether the emissions standards provide an
ample margin of safety ``in consideration of all health information,
including the number of persons at risk levels higher than
approximately [1-in-1 million], as well as other relevant factors,
including costs and economic impacts, technological feasibility, and
other factors relevant to each particular decision.'' Id. The EPA must
promulgate emission standards necessary to provide an ample margin of
safety to protect public health. 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.
---------------------------------------------------------------------------

    \2\ 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 frequently than every eight 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).

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

1. What is the Surface Coating of Large Appliances source category and
how does the current NESHAP regulate its HAP emissions?
a. Source Category Description
    The NESHAP for the Surface Coating of Large Appliances source
category was promulgated on July 23, 2002 (67 FR 48254), and codified
at 40 CFR part 63, subpart NNNN. As promulgated in 2002, the Surface
Coating of Large Appliances NESHAP applies to the surface coating and
related operations at each new and existing affected source of HAP
emissions at facilities that are major sources and are engaged in the
surface coating of a large appliance part or product. The Surface
Coating of Large Appliances NESHAP (40 CFR 63.4081) defines a ``large
appliance part or product'' as ``a component of a large appliance
product manufactured for household, recreational, institutional,
commercial, or industrial use'' including, but not limited to,
``cooking equipment; refrigerators, freezers, and refrigerated cabinets
and cases; laundry equipment; dishwashers, trash compactors, and water
heaters; and heating, ventilation, and air-conditioning (HVAC) units,
air-conditioning (except motor vehicle) units, air-conditioning and
heating combination units, comfort furnaces, and electric heat pumps.
Specifically excluded are heat transfer coils and large commercial and
industrial chillers.''
    Based on our search of the National Emission Inventory (NEI)
(www.epa.gov/air-emissions-inventories/national-emissions-inventory-nei) and the EPA's

Enforcement and Compliance History Online (ECHO) database
(www.echo.epa.gov) and a review of active air emissions permits, we
estimate that ten facilities are subject to the Surface Coating of
Large Appliances NESHAP. A complete list of facilities subject to the
Surface Coating of Large Appliances NESHAP is available in Table 1 of
Appendix 10 to the memorandum titled Residual Risk Assessment for the
Surface Coating of Large Appliances Source Category in Support of the
May 2018 Risk and Technology Review Proposed Rule (hereafter referred
to as the Large Appliances Risk Assessment Report) in the Large
Appliances Docket (Docket ID No. EPA-HQ-OAR-2017-0670). The Surface
Coating of Large Appliances NESHAP also defines a coating as a
``material that is applied to a substrate for decorative, protective or
functional purposes. Such materials include, but are not limited to,
paints, sealants, caulks, inks, adhesives, and maskants. Decorative,
protective, or functional materials that consist only of protective
oils, acids, bases, or any combination of these substances are not
considered coatings for the purposes of this subpart.''
b. HAP Emission Sources
    The primary HAP emitted from large appliance surface coating
operations are organic HAP and include xylene, glycol ethers, toluene,
methanol, ethyl benzene, methylene chloride, and methyl isobutyl ether.
Approximately 80 percent of the HAP emissions from the Surface Coating
of Large Appliances source category occur from the coating operations
and from the mixing and storage areas. At the time of the original rule
promulgation in 2002, most large appliance coating was applied either
by using a spray gun in a spray booth or by dipping the substrate in a
tank. Inorganic HAP emissions were considered in the development of the
Surface Coating of Large Appliances NESHAP. Inorganic HAP, including
chromium, cobalt, lead, and manganese compounds, are components of some
specialty coatings used by this source category. However, most of the
inorganic HAP components remain as solids in the dry coating film on
the parts being coated or are deposited onto the walls, floor, and
grates of the spray booths in which they are applied. The remaining
inorganic HAP particles are entrained in the spray booth exhaust air.
Spray booths in the large appliance industry typically have either
water curtains or dry filters to remove overspray particles from the
exhaust air. No inorganic HAP were reported in the cleaning materials
in the data collected to develop the Surface Coating of Large
Appliances NESHAP. No inorganic HAP were reported in the NEI data used
for this RTR for surface coating operations at major source large
appliance manufacturing facilities.
c. NESHAP Requirements for Control of HAP
    We estimated that the Surface Coating of Large Appliances NESHAP
requirements would reduce the emissions of organic HAP from the source
category by 45 percent or 1,191 tons per year (67 FR 48259, July 23,
2002). The NESHAP specifies numerical emission limits for organic HAP
emissions from surface coating application operations. The organic HAP
emission limit for existing sources is 0.13 kilogram (kg) organic HAP/
liter (1.1 pound/gallon (lb/gal)) of coating solids and for new or
reconstructed sources is 0.022 kg organic HAP/liter (0.18 lb/gal) of
coating solids.
    The Surface Coating of Large Appliances NESHAP provides existing
sources three compliance options: (1) Compliant coatings i.e., all
coatings have less than or equal to 0.13 kg organic HAP/liter (1.1
pound/gallon (lb/gal)) of coating solids; (2) emission rate without
add-on controls; or (3) emission rate with add-on controls.
    For any coating operation(s) on which the facility uses the
compliant material option or the emission rate without add-on controls
option, the facility is not required to meet any work practice
standards.
    If the facility uses the emission rate with add-on controls option,
the facility must develop and implement a work practice plan to
minimize organic HAP emissions from the storage, mixing, and conveying
of coatings, thinners, and cleaning materials used in, and waste
materials generated by, the coating operation(s) using that option. The
plan must specify practices and procedures to ensure that a set of
minimum work practices specified in the NESHAP are implemented. The
facility must also comply with site-specific operating limits for the
emission capture and control system.
2. What is the Printing, Coating, and Dyeing of Fabrics and Other
Textiles source category and how does the current NESHAP regulate its
HAP emissions?
a. Source Category Description
    The NESHAP for the Printing, Coating, and Dyeing of Fabrics and
Other Textiles source category was promulgated on May 29, 2003 (68 FR
32172), and codified at 40 CFR part 63, subpart OOOO. As promulgated in
2003, the Printing, Coating, and Dyeing of Fabrics and Other Textiles
NESHAP applies to the printing, coating, slashing, dyeing, or finishing
of fabrics and other textiles and related operations at each new and
existing affected source of HAP emissions at facilities that are major
sources and are engaged in the printing, coating, slashing, dyeing, or
finishing of fabrics and other textiles. The Printing, Coating, and
Dyeing of Fabrics and Other Textiles NESHAP (40 CFR 63.4371) defines a
fabric as any woven, knitted, plaited, braided, felted, or non-woven
material made of filaments, fibers, or yarns including thread. This
term includes material made of fiberglass, natural fibers, synthetic
fibers, or composite. The NESHAP defines textile as any one of the
following: (1) Staple fibers and filaments suitable for conversion to
or use as yarns, or for the preparation of woven, knit, or nonwoven
fabrics; (2) Yarns made from natural or manufactured fibers; (3)
Fabrics and other manufactured products made from staple fibers and
filaments and from yarn; and (4) Garments and other articles fabricated
from fibers, yarns, or fabrics.
    Based on our search of the NEI and EPA's ECHO database and a review
of active air emission permits, we estimate that 43 facilities are
subject to the Printing, Coating, and Dyeing of Fabrics and Other
Textiles NESHAP. A complete list of facilities we identified as subject
to the Printing, Coating, and Dyeing of Fabrics and Other Textiles
NESHAP is available in Table 1 of Appendix 10 to the memorandum titled
Residual Risk Assessment for the Printing, Coating, and Dyeing of
Fabrics and Other Textiles Source Category in Support of the May 2018
Risk and Technology Review Proposed Rule) hereafter referred to as the
Fabrics and Other Textiles Risk Assessment Report), in the Fabrics and
Other Textiles Docket (Docket ID No. EPA-HQ-OAR-2017-0668).
    The Printing, Coating, and Dyeing of Fabrics and Other Textiles
NESHAP also defines a coating material as an elastomer, polymer, or
prepolymer material applied as a thin layer to a textile web. Such
materials include, but are not limited to, coatings, sealants, inks,
and adhesives. Decorative, protective, or functional materials that
consist only of acids, bases, or any combination of these substances
are not considered coating materials for the purposes of this subpart.
Thinning materials also are not included in this

definition of coating materials but are accounted for separately.
b. HAP Emission Sources
    The primary HAP emitted from printing, coating, and dyeing
operations are organic HAP and include toluene, phenol, methanol, and
N,N-dimethylformamide. The majority of organic HAP emissions (greater
than 95 percent) come from the coating and printing subcategories, with
the remainder coming from dyeing and finishing.
    Inorganic HAP emissions were considered in the development of the
Printing, Coating, and Dyeing of Fabrics and Other Textiles NESHAP.
Based on information reported in survey responses during the
development of the 2002 proposed NESHAP, inorganic HAP, including
chromium, cobalt, hydrogen chloride (HCl), lead, manganese compounds,
and nickel were components of some coatings, dyes, and finishes used by
this source category. However, we concluded that inorganic HAP are not
likely to be emitted from these sources because of the application
techniques used (67 FR 46032, July 11, 2002). No inorganic HAP were
reported in the NEI data used for this RTR for printing, coating, and
dyeing of fabrics and other textiles operations at major source
facilities.
c. NESHAP Requirements for Control of HAP
    We estimated that the Printing, Coating, and Dyeing of Fabrics and
Other Textiles NESHAP requirements would reduce the emissions of
organic HAP from the source category by 60 percent or 4,100 tpy (68 FR
32172, May 29, 2003). The NESHAP specifies numerical emission limits
for organic HAP emissions from three subcategories of surface coating
application operations: Printing and coating; dyeing and finishing; and
slashing. The organic HAP emission limit for existing printing or
coating affected sources is 0.12 kg organic HAP/kg (lb/lb) of coating
solids applied and for new or reconstructed affected sources is 0.08 kg
organic HAP/kg (lb/lb) of coating solids applied. Printing or coating
affected sources may also demonstrate compliance by achieving at least
a 98-percent HAP reduction for new affected sources or a 97-percent HAP
reduction for existing sources. New and existing sources using a
thermal oxidizer may also comply by achieving a HAP concentration at
the oxidizer outlet of no greater than 20 parts per million by volume
(ppmv) on a dry basis and having an emission capture system with 100-
percent efficiency.
    For new, reconstructed, or existing dyeing and finishing
operations, the emission limit for conducting dyeing operations is
0.016 kg organic HAP/kg (lb/lb) dyeing materials applied; the limit for
conducting finishing operations is 0.0003 kg organic HAP/kg (lb/lb)
finishing materials applied; and the limit for conducting both dyeing
and finishing operations is 0.016 kg organic HAP/kg (lb/lb) dyeing and
finishing materials applied. For new, reconstructed, or existing
slashing operations, the slashing materials must contain no organic HAP
(each organic HAP that is not an Occupational Safety and Health
Administration (OSHA)-defined carcinogen that is measured to be present
at less than one percent by weight is counted as zero).
    For any coating, printing, or dyeing operation(s) on which the
facility uses the compliant material option or the emission rate
without add-on controls option, the facility is not required to meet
any work practice standards.
    If the facility uses an add-on control device to demonstrate
compliance, the facility must develop and implement a work practice
plan to minimize organic HAP emissions from the storage, mixing, and
conveying of coatings, thinners, and cleaning materials used in, and
waste materials generated by, the coating operation(s) using that
option. The plan must specify practices and procedures to ensure that a
set of minimum work practices specified in the NESHAP are implemented.
The facility must also comply with site-specific operating limits for
the emission capture and control system.
3. What is the Surface Coating of Metal Furniture source category and
how does the current NESHAP regulate its HAP emissions?
a. Source Category Description
    The NESHAP for the Surface Coating of Metal Furniture source
category was promulgated on May 23, 2003 (68 FR 28606), and codified at
40 CFR part 63, subpart RRRR. As promulgated in 2003, the Surface
Coating of Metal Furniture NESHAP applies to the surface coating and
related operations at each new and existing affected source of HAP
emissions at facilities that are major sources and are engaged, either
in part or in whole, in the surface coating of metal furniture. The
Surface Coating of Metal Furniture NESHAP (40 CFR 63.4881) defines
metal furniture as furniture or components of furniture constructed
either entirely or partially from metal. Metal furniture includes, but
is not limited to, components of the following types of products as
well as the products themselves: Household, office, institutional,
laboratory, hospital, public building, restaurant, barber and beauty
shop, and dental furniture; office and store fixtures; partitions;
shelving; lockers; lamps and lighting fixtures; and wastebaskets.
    Based on our search of the NEI and the EPA's ECHO database and a
review of active air emission permits, we estimate that 16 facilities
are subject to the Surface Coating of Metal Furniture NESHAP. A
complete list of facilities subject to the Surface Coating of Metal
Furniture NESHAP is available in Table 1 of Appendix 10 to the
memorandum titled Residual Risk Assessment for the Surface Coating of
Metal Furniture Source Category in Support of the May 2018 Risk and
Technology Review Proposed Rule (hereafter referred to as the Metal
Furniture Risk Assessment Report), in the Metal Furniture Docket
(Docket ID No. EPA-HQ-OAR-2017-0669). The Surface Coating of Metal
Furniture NESHAP defines a coating as a ``material that is applied to a
substrate for decorative, protective, or functional purposes. Such
materials include, but are not limited to, paints, sealants, caulks,
inks, adhesives, and maskants.''
b. HAP Emission Sources
    Most of the organic HAP emissions from metal furniture surface
coating operations occur from the coating application operations and
the drying and curing ovens. In most cases, HAP emissions from surface
preparation, storage, and handling are relatively small for this source
category. The primary organic HAP emitted from metal furniture surface
coating operations are xylene, glycol ethers, ethylbenzene, toluene,
and cumene. These compounds account for more than 95 percent of this
category's nationwide organic HAP emissions from major sources.
    Inorganic HAP emissions, such as chromium, lead, and manganese
compounds, were considered in the development of the Surface Coating of
Metal Furniture NESHAP, and the EPA determined that inorganic HAP
emissions would be very low (67 FR 20206, April 24, 2002). At that
time, approximately 680 coatings were reported in the survey responses
from the metal furniture industry, and only two coatings were reported
as containing inorganic HAP. In the NEI data used for this risk and
technology review, only one facility reported inorganic HAP emissions
(antimony, 0.015 tpy, and nickel, 0.003 tpy) from metal furniture
surface coating operations. According to the reporting facility, the
reported emissions in the

NEI were conservatively over-estimated by an approximate factor of
10.\3\
---------------------------------------------------------------------------

    \3\ Telephone communication between Kaye Whitfield, U.S. EPA and
Marley Ayres, Pinnacle Engineering, February 7, 2018.
---------------------------------------------------------------------------

c. NESHAP Requirements for Control of HAP
    We estimated the Surface Coating of Metal Furniture NESHAP
requirements would reduce the emissions of organic HAP from the source
category by 73 percent or 16,300 tpy (68 FR 28606, May 23, 2003). The
NESHAP specifies numerical emission limits for organic HAP emissions
from surface coating application operations. The organic HAP emission
rate for existing sources is no more than 0.10 kg organic HAP/liter
(0.83 lb/gal) of coating solids used during each compliance period. A
new or reconstructed affected source can emit no organic HAP during any
compliance period unless a source requests approval from the
Administrator to use an alternative new source emission limit for
specific metal furniture components or types of components.
    The Surface Coating of Metal Furniture NESHAP provides existing
sources three compliance options: (1) Use only compliant coatings i.e.,
all coatings have less than or equal to 0.10 kg organic HAP/liter (0.83
lb/gal) of coating solids used; (2) collectively manage the coatings
such that the monthly emission rate of organic HAP is less than or
equal to 0.10 kg organic HAP/liter (0.83 lb/gal) coating solids used;
or (3) use emission capture systems and control devices to achieve an
organic HAP emission rate of less than or equal to 0.10 kg organic HAP/
liter (0.83 lb/gal) coating solids used.
    For any metal furniture coating operation(s) on which the facility
uses the compliant material option or the emission rate without add-on
controls option, the facility is not required to meet any work practice
standards.
    If the facility uses an add-on control device to demonstrate
compliance, the facility must develop and implement a work practice
plan to minimize organic HAP emissions from the storage, mixing, and
conveying of coatings, thinners, and cleaning materials used in, and
waste materials generated by, the coating operation(s) using that
option. The plan must specify practices and procedures to ensure that a
set of minimum work practices specified in the NESHAP are implemented.
The facility must also comply with site-specific operating limits for
the emission capture and control system.

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

    For the risk modeling portion of these RTRs, the EPA used data from
the 2011 and 2014 NEI. The NEI is a database that contains information
about sources that emit criteria air pollutants, their precursors, and
HAP. The database includes estimates of annual air pollutant emissions
from point, nonpoint, and mobile sources in the 50 states, the District
of Columbia, Puerto Rico, and the Virgin Islands. The EPA collects this
information and releases an updated version of the NEI database every
three years. The NEI includes data necessary for conducting risk
modeling, including annual HAP emissions estimates from individual
emission points at facilities and the related emissions release
parameters. We used NEI emissions and supporting data as the primary
data to develop the model input files for the risk assessments for each
of these three source categories. Additional information on the
development of the modeling file for each source category can be found
in Appendix 1 to the Large Appliances Risk Assessment Report in the
Large Appliances Docket (Docket ID No. EPA-HQ-OAR-2017-0670), Appendix
1 to the Fabrics and Other Textiles Risk Assessment Report in the
Fabrics and Other Textiles Docket (Docket ID No. EPA-HQ-OAR-2017-0668),
and Appendix 1 to the Metal Furniture Risk Assessment Report in the
Metal Furniture Docket (Docket ID No. EPA-HQ-OAR-2017-0669).
    For both the risk modeling and technology review portion of these
RTRs, we also gathered data from facility construction and operating
permits, regarding emission points, air pollution control devices, and
process operations. We collected permits and supporting documentation
from state permitting authorities through state-maintained online
databases. The facility permits were also used to confirm that the
facilities were major sources of HAP and were subject to the NESHAP
that are the subject of these risk assessments. In certain cases, we
contacted facility owners or operators to confirm and clarify the
sources of emissions that were reported in the NEI. No formal
information collection request was performed.
    For the technology review portion of these RTRs, we also used
information from the EPA's ECHO database as a tool to identify which
facilities were potentially subject to the NESHAP. The ECHO database
provides integrated compliance and enforcement information for
approximately 800,000 regulated facilities nationwide. Using the search
feature in ECHO, the EPA identified facilities that could potentially
be subject to each of these three NESHAP. We then reviewed operating
permits for these facilities, when available, to confirm that they were
major sources of HAP with emission sources subject to these NESHAP.
    Also for the technology reviews, we collected information from the
Reasonably Available Control Technology (RACT), Best Available Control
Technology (BACT), and Lowest Achievable Emission Rate (LAER)
determinations in the EPA's RACT/BACT/LAER Clearinghouse (RBLC).\4\
This 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 by a large amount, an
NSR permit must be obtained. This central database 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
surface coating operations to reduce air emissions.
---------------------------------------------------------------------------

    \4\ https://www.epa.gov/catc/ractbactlaer-clearinghouse-rblc-basic-information.
---------------------------------------------------------------------------

    Additional information about these data collection activities for
the technology reviews is contained in the technology review memoranda
titled Technology Review for Surface Coating Operations in the Large
Appliance Category, August 2017 (hereafter referred to as the Large
Appliances Technology Review Memo), Technology Review for Printing,
Coating, and Dyeing Category, August 2017 (hereafter referred to as the
Fabrics and Other Textiles Technology Review Memo), and Technology
Review for Surface Coating Operations in the Metal Furniture Category,
September 2017 (hereafter referred to as the Metal Furniture Technology
Review Memo), available respectively in the Large Appliances Docket,
Fabrics and Other Textiles Docket, and Metal Furniture Docket.

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

    For the technology review for each source category, we reviewed the
NESHAP for various industries that were promulgated since the MACT
standards being reviewed in this action.

We reviewed the regulatory requirements and/or technical analyses
associated with these later regulatory actions to identify any
practices, processes, and control technologies considered in those
rulemakings that could be applied to emission sources in each of these
three source categories, as well as the costs, non-air impacts, and
energy implications associated with the use of those technologies. We
also reviewed information available in the American Coatings
Association's (ACA) Industry Market Analysis, 9th Edition (2014-
2019),\5\ for the Surface Coating of Metal Furniture and Surface
Coating of Large Appliances source categories. The ACA Industry Market
Analysis provided information on trends in coatings technology that can
affect emissions from the metal furniture and large appliance source
categories, but did not address the Printing, Coating, and Dyeing of
Fabrics and Other Textiles source category. Additional details
regarding our review of these information sources are contained in the
Large Appliances Technology Review Memo, the Fabrics and Other Textiles
Technology Review Memo, and the Metal Furniture Technology Review Memo,
available in the Large Appliances Docket, Fabrics and Other Textiles
Docket, and Metal Furniture Docket, respectively.
---------------------------------------------------------------------------

    \5\ Prepared for the American Coatings Association, Washington,
DC, by The ChemQuest Group, Inc., Cincinnati, Ohio. 2015.
---------------------------------------------------------------------------

III. Analytical Procedures

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

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 38046,
September 14, 1989. 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 the HAP
emissions 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.\6\ The assessment
also provides estimates of the distribution of cancer risks within the
exposed populations, cancer incidence, and an evaluation of the
potential for adverse environmental effects. The scope of EPA's risk
analysis is consistent with EPA's response to comments on our policy
under the Benzene NESHAP where the EPA explained that:
---------------------------------------------------------------------------

    \6\ 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
exposure to the HAP to the level at or below which no adverse
chronic noncancer effects are expected; the HI is the sum of HQs for
HAP that affect the same target organ or organ system.
---------------------------------------------------------------------------

    ``[t]he policy chosen by the Administrator permits consideration of
multiple measures of health risk. Not only can the MIR figure be
considered, but also incidence, the presence of noncancer health
effects, and the uncertainties of the risk estimates. In this way, the
effect on the most exposed individuals can be reviewed as well as the
impact on the general public. These factors can then be weighed in each
individual case. This approach complies with the Vinyl Chloride mandate
that the Administrator ascertain an acceptable level of risk to the
public by employing 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'.'' See
54 FR 38057, September 14, 1989.
    Thus, the level of the MIR is only one factor to be weighed in
determining acceptability of risks. The Benzene NESHAP explained that
``an MIR of approximately one in ten thousand should ordinarily be the
upper end of the range of acceptability. As risks increase above this
benchmark, they become presumptively less acceptable under CAA section
112, and would be weighed with the other health risk measures and
information in making an overall judgment on acceptability. Or, the
Agency may find, in a particular case, that a risk that includes MIR
less than the presumptively acceptable level is unacceptable in the
light of other health risk factors.'' Id. at 38045. Similarly, with
regard to the ample margin of safety analysis, the EPA stated in the
Benzene NESHAP that: ``EPA believes the relative weight of the many
factors that can be considered in selecting an ample margin of safety
can only be determined for each specific source category. This occurs
mainly because technological and economic factors (along with the
health-related factors) vary from source category to source category.''
Id. at 38061. We also consider the uncertainties associated with the
various risk analyses, as discussed earlier in this preamble, in our
determinations of acceptability and ample margin of safety.
    The EPA notes that it has not considered certain health information
to date in making residual risk determinations. At this time, we do not
attempt to quantify those HAP risks that may be associated with
emissions from other facilities that do not include the source
categories under review, mobile source emissions, natural source
emissions, persistent environmental pollution, or atmospheric
transformation in the vicinity of the sources in the categories.
    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 risks, 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 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.'' \7\
---------------------------------------------------------------------------

    \7\ The EPA's responses to this and all other key
recommendations of the SAB's advisory on RTR risk assessment
methodologies (which is available at: https://yosemite.epa.gov/sab/
sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-
007-unsigned.pdf) are outlined in a memorandum to this rulemaking
docket from David Guinnup titled EPA's Actions in Response to the
Key Recommendations of the SAB Review of RTR Risk Assessment
Methodologies.
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    In response to the SAB recommendations, the EPA is incorporating
certain cumulative risk analyses into its RTR risk assessments,
including those reflected in this proposal. Specifically, the Agency is
(1) conducting facility-wide assessments, which include source category
emission points, as well as other emission points within the
facilities; (2) combining exposures from multiple sources in the same
category that could affect the same individuals; and (3) for some
persistent and bioaccumulative pollutants, analyzing the ingestion
route of exposure. In addition, the RTR risk assessments have always
considered aggregate cancer risk from all carcinogens and aggregate
noncancer HI from all noncarcinogens affecting the same target organ
system.
    Although we look at the cumulative risks from all sources at
facilities within the category, we do not assess the cumulative risks
from facilities outside the category that may be in the vicinity. We
are interested in placing source category and facility-wide HAP risks
in the context of total HAP risks from all sources of HAP in the
vicinity of each source. However, because of the contribution to total
HAP risk from emission sources other than those that we have studied,
in depth, during this RTR review, such estimates of total HAP risks
would have significantly greater associated uncertainties than the
source category or facility-wide estimates. Such aggregate or
cumulative assessments would compound those uncertainties, making the
assessments too unreliable.

B. How do we perform the technology review?

    Our technology reviews focus 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, in order to inform our decision of whether
it is ``necessary'' to revise the emissions standards, we analyze the
technical feasibility of applying these developments and the estimated
costs, energy implications, and non-air environmental impacts, and we
also consider the emission reductions. In addition, we consider the
appropriateness of applying controls to future affected sources versus
retrofitting affected sources currently subject to the NESHAP.
    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
     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 (i.e., the 2002 Surface Coating of Large Appliances NESHAP;
the 2003 Printing, Coating, and Dyeing of Fabrics and Other Textiles
NESHAP; and the 2003 Surface Coating of Metal Furniture NESHAP), we
reviewed a variety of data sources in our investigation of potential
practices, processes, or controls that were not considered for each of
the three source categories during development of the NESHAP. Among the
sources we reviewed were the NESHAP for various industries that were
promulgated since the MACT standards being reviewed in this action
(e.g., NESHAP for Miscellaneous Metal Parts and Products (40 CFR part
63, subpart MMMM)). We also reviewed the results of other technology
reviews for other surface coating source categories since the
promulgation of the NESHAP (e.g., the technology reviews conducted for
the Shipbuilding and Ship Repair (Surface Coating) NESHAP (40 CFR part
63, subpart II) and the Wood Furniture Manufacturing Operations NESHAP
(40 CFR part 63, subpart JJ)). We reviewed the regulatory requirements
and/or technical analyses associated with these regulatory actions to
identify any practices, processes, and control technologies considered
in these efforts that could be applied to emission sources in the
Surface Coating of Large Appliances source category, the Printing,
Coating, and Dyeing of Fabrics and Other Textiles source category, and
the Surface Coating of Metal Furniture source category, as well as the
costs, non-air impacts, and energy implications associated with the use
of these technologies. Finally, we reviewed information from other
sources, such as state and/or local permitting agency databases and
industry-sponsored market analyses and trade journals, searching for
advancements in add-on controls, advancements in lower HAP technology
for coatings and solvents. For a more detailed discussion of our
methods for performing these technology reviews, refer to the Large
Appliances Technology Review Memo, the Fabrics and Other Textiles
Technology Review Memo, and the Metal Furniture Technology Review Memo,
available respectively in the Large Appliances Docket, Fabrics and
Other Textiles Docket, and Metal Furniture Docket.

C. How did we estimate post-MACT risks posed by these source
categories?

    The EPA conducted risk assessments that provide estimates of the
MIR for cancer posed by the HAP emissions from each source in each
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
assessments also provide estimates of the distribution of cancer risks
within the exposed populations, cancer incidence, and an evaluation of
the potential for adverse environmental effects. The seven sections
that follow this paragraph describe how we estimated emissions and
conducted the risk assessments. The Large Appliances Docket, Fabrics
and Other Textiles Docket, and Metal Furniture Docket contain,
respectively, the Large Appliances Risk Assessment Report, the Fabrics
and Other Textiles Risk Assessment Report, and the Metal Furniture Risk
Assessment Report, which provide more information on the

risk assessment inputs and models. The methods used to assess risks (as
described in the seven primary steps below) are consistent with those
peer-reviewed by a panel of the EPA's SAB in 2009 and described in
their peer review report issued in 2010; \8\ they are also consistent
with the key recommendations contained in that report.
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    \8\ U.S. EPA SAB. Risk and Technology Review (RTR) Risk
Assessment Methodologies: For Review by the EPA's Science Advisory
Board with Case Studies--MACT I Petroleum Refining Sources and
Portland Cement Manufacturing, May 2010.
---------------------------------------------------------------------------

1. How did we estimate actual emissions and identify the emissions
release characteristics?
    The actual emissions and the emission release characteristics for
each facility were obtained primarily from either the 2011 NEI or the
2014 NEI. Most data were obtained from the 2011 NEI, unless the 2014
NEI included HAP data for emission units or processes for which the
2011 NEI included only volatile organic compounds (VOC) or particulate
matter. In some cases, the facilities were contacted to confirm
emissions that appeared to be outliers, that were otherwise
inconsistent with our understanding of the industry, or that were
associated with high risk values in our initial risk screening
analyses. When appropriate, emission values and release characteristics
were corrected based on these facility contacts, and these changes were
documented. Additional information on the development of the modeling
file for each source category, including the development of the actual
emissions and emissions release characteristics, can be found in
Appendix 1 to the Large Appliances Risk Assessment Report in the Large
Appliances Docket, Appendix 1 to the Fabrics and Other Textiles Risk
Assessment Report in the Fabrics and Other Textiles Docket, and
Appendix 1 to the Metal Furniture Risk Assessment Report in the Metal
Furniture Docket.
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 level allowed to be emitted under the MACT
standards is referred to as the ``MACT-allowable'' emissions level. We
discussed the use of both MACT-allowable and actual emissions in the
final Coke Oven Batteries RTR (70 FR 19998-19999, April 15, 2005) and
in the proposed and final Hazardous Organic NESHAP RTRs (71 FR 34428,
June 14, 2006, and 71 FR 76609, December 21, 2006, respectively). In
those actions, we noted that assessing the risks at the MACT-allowable
level is inherently reasonable since these risks reflect the maximum
level facilities could emit and still comply with national emission
standards. We also explained that it is reasonable to consider actual
emissions, where such data are available, in both steps of the risk
analysis, in accordance with the Benzene NESHAP approach. (54 FR 38044,
September 14, 1989.)
    For the Surface Coating of Large Appliances source category, the
EPA calculated allowable emissions by developing a source category-
specific multiplier of 1.2 that was applied to the current emissions to
estimate allowable emissions. The multiplier was calculated using
annual coating sales volumes provided in the ACA Industry Market
Analysis for appliance finishes in the years 2005 to 2014. For more
information on how the EPA calculated the MACT-allowable emissions for
the Surface Coating of Large Appliances source category, please see
Appendix 1 to the Large Appliances Risk Assessment Report in the Large
Appliances Docket (Docket ID No. EPA-HQ-OAR-2017-0670).
    For the Printing, Coating, and Dyeing of Fabrics and Other Textiles
source category, the EPA calculated allowable emissions by developing a
source category-specific multiplier of 1.1 that was applied to the
current emissions to estimate allowable emissions. We gathered current
and historical publicly available category-specific production data
from U.S. Census and based the calculation on plant capacity
utilization rates for six different NAICS codes related to fabric and
textile production for the years 2008 to 2016. We assumed the annual
plant capacity utilization rates represented industry annual production
rates. The multiplier of 1.1, or the ratio of the peak annual
utilization rate in 2013 to the average annual utilization rate for the
years 2008 to 2016, was applied to the actual emissions to estimate
allowable emissions. For more details on how the EPA calculated the
MACT-allowable emissions for the Printing, Coating, and Dyeing of
Fabrics and Other Textiles source category, please see Appendix 1 to
the Fabrics and Other Textiles Risk Assessment Report in the Fabrics
and Other Textiles Docket (Docket ID No. EPA-HQ-OAR-2017-0668).
    For the Surface Coating of Metal Furniture source category, the EPA
calculated allowable emissions by developing a source category-specific
multiplier of 1.8 that was applied to the current emissions to estimate
allowable emissions. The multiplier was calculated using annual coating
sales volumes from the ACA Industry Market Analysis for non-wood
furniture, fixture, and business equipment coatings from 2005 to 2014.
For more details on how the EPA calculated the MACT-allowable emissions
for the Surface Coating of Metal Furniture source category, please see
Appendix 1 to the Metal Furniture Risk Assessment Report in the Metal
Furniture Docket (Docket ID No. EPA-HQ-OAR-2017-0669).
3. How did we conduct dispersion modeling, determine inhalation
exposures, and estimate individual and population inhalation risks?
    Both long-term and short-term inhalation exposure concentrations
and health risks from the source categories addressed in this proposal
were estimated using the Human Exposure Model (HEM-3). 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 risks
using the exposure estimates and quantitative dose-response
information.
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 facilities.\9\ 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 one year (2016) of
hourly surface and upper air observations from 824 meteorological
stations, selected to provide coverage of the U.S. and Puerto Rico. A
second library of U.S. Census Bureau census block \10\ 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 risks. These dose-response
values are the latest values recommended by the EPA for HAP. They are
available at https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants and
are discussed in more detail later in this section.
---------------------------------------------------------------------------

    \9\ 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).
    \10\ A census block is the smallest geographic area for which
census statistics are tabulated.
---------------------------------------------------------------------------

b. Risk From Chronic Exposure to HAP That May Cause Cancer
    In developing the risk assessment for chronic exposures, we used
the estimated annual average ambient air concentrations of each HAP
emitted by each source for which we have emissions data in the source
categories. The air concentrations at each nearby census block centroid
were used as a surrogate for the chronic inhalation exposure
concentration for all the people who reside in that census block. We
calculated the MIR for each facility as the cancer risk associated with
a continuous lifetime (24 hours per day, seven days per week, 52 weeks
per year, for a 70-year period) exposure to the maximum concentration
at the centroid of inhabited census blocks. Individual cancer risks
were calculated by multiplying the estimated lifetime exposure to the
ambient concentration of each HAP (in micrograms per cubic meter) by
its unit risk estimate (URE). The URE is an upper bound estimate of an
individual's probability of contracting cancer over a lifetime of
exposure to a concentration of one microgram of the pollutant per cubic
meter of air. For residual risk assessments, we generally use 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.
    To estimate incremental individual lifetime cancer risks associated
with emissions from the facilities in the source categories, the EPA
summed the risks for each of the carcinogenic HAP \11\ emitted by the
modeled sources. Cancer incidence and the distribution of individual
cancer risks for the population within 50 km of the sources were also
estimated for the source category by summing individual risks. 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.
---------------------------------------------------------------------------

    \11\ The EPA 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 risks of these individual compounds to obtain the cumulative
cancer risks is an approach that was recommended by the EPA's SAB in
their 2002 peer review of the EPA's National Air Toxics Assessment
(NATA) 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.
---------------------------------------------------------------------------

c. Risk From Chronic Exposure to HAP That May Cause Health Effects
Other Than Cancer
    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 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 (https://iaspub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&vocabName=IRIS%20Glossary), 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.'' In cases where an RfC from
the EPA's IRIS database 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 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.
d. 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. We use the peak hourly emission rate (when
available),\12\ worst-case dispersion conditions, and, in accordance
with our mandate under section 112 of the CAA, the point of highest
off-site exposure to assess the potential risk to the maximally exposed
individual.
---------------------------------------------------------------------------

    \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) and dividing by
the total number of hours in a year (8,760 hours) to account for
variability. This is documented in Large Appliances Risk Assessment
Report, Fabrics and Other Textiles Risk Assessment Report, and Metal
Furniture Risk Assessment Report and in Appendix 5 of the report:
Analysis of Data on Short-term Emission Rates Relative to Long-term
Emission Rates. These documents are available in the Large
Appliances Docket, Fabrics and Other Textiles Docket, and Metal
Furniture Docket.
---------------------------------------------------------------------------

    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 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 ten minutes to eight
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.
---------------------------------------------------------------------------

    \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 one 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 these source categories, we did not have short term emissions
data; therefore, we developed source category-specific factors based on
information about each industry. We request comment on our assumptions
regarding hour-to-hour variation in emissions and our methods of
calculating the multiplier for estimating the peak 1-hour emissions for
each source category and any additional information that could help
refine our approach.
    For the Surface Coating of Large Appliances source category, we do
not expect to see substantial hour-to-hour variation in emissions
during routine operations because the industry employs the use of
compliant low HAP coatings in a continuous (non-batch) coating process.
Thus, applying the default emission factor of ten to estimate the
worst-case hourly emission rate is not reasonable for this category. We
expect that minimal variations in emissions could possibly occur due to
cleaning of process equipment during routine operations for coating
operations using the emission rate without add-on controls compliance
option. We calculated worst-case hourly emissions by developing a
source category-specific multiplier of 1.2 that was applied to the
annual emissions, which were then divided by the total number of hours
in a year (8,760 hours). The multiplier was based on historical data on
coating sales volumes from the ACA Industry Market Analysis for
appliance finishes 2005 to 2014. The multiplier was the ratio of the
peak coating sales volume (in gallons) in 2006 to the average sales
volume for the years 2005 to 2014. The peak coating sales volume in
2006 was assumed to represent the maximum utilization of the current
large appliance surface coating industry. A further discussion of why
this factor was chosen can be found in Appendix 1 to the Large
Appliances Risk Assessment Report in the Large Appliances Docket.
    For the Printing, Coating, and Dyeing of Fabrics and Other Textiles
source category, we do not expect to see substantial hour-to-hour
variation in emissions during routine operations because the industry
employs the use of various compliance options, including add-on
controls, compliant low HAP coatings, or emission rate without add-on
controls option, in a continuous (non-batch) coating process that
achieve consistent emission rates. Thus, applying the default emission
factor of ten to estimate the worst-case hourly emission rate is not
reasonable for this category. We expect that minimal variations in
emissions could possibly occur during routine operations due to
cleaning of process equipment. We calculated acute emissions by
developing a source category-specific multiplier of 1.4 that was
applied to the annual emissions, which were then divided by the total
number of hours in a year (8,760 hours). The multiplier was based on
historical U.S. Census data on plant capacity utilization rates for six
different NAICS codes related to fabric and textile production for the
years 2008 to 2016. The multiplier was the ratio of the maximum
utilization rate (100 percent) to the peak utilization rate of 71.7
percent for the years 2008 to 2016. A further discussion of why this
factor was chosen can be found in Appendix 1 to the Fabrics and Other
Textiles Risk Assessment Report in the Fabrics and Other Textiles
Docket.
    For the Surface Coating of Metal Furniture source category, we do
not expect to see substantial hour-to-hour variation in emissions
during routine operations because the industry employs the use of
compliant low HAP

coatings in a continuous (non-batch) coating process. Thus, applying
the default emission factor of ten to estimate the worst-case hourly
emission rate is not reasonable for this category. We expect that
minimal variations in emissions could possibly occur due to cleaning of
process equipment during routine operations for coating operations
using the emission rate without add-on controls compliance option. We
calculated worst-case hourly emissions by developing a source category-
specific multiplier of 1.8 that was applied to the annual emissions,
which were then divided by the total number of hours in a year (8,760
hours). The multiplier was based on historical data on coating sales
volumes from the ACA Industry Market Analysis for non-wood furniture,
fixture and business equipment coatings from 2005 to 2014. The
multiplier was the ratio of the peak coating sales volume (in gallons)
in 2005 to the average sales volume for the years 2005 to 2014. The
peak sales volume in 2005 was assumed to represent maximum utilization
of the current metal furniture surface coating industry. A further
discussion of why this factor was chosen can be found in Appendix 1 to
the Metal Furniture Risk Assessment Report in the Metal Furniture
Docket.
    In our acute inhalation screening risk assessment, acute impacts
are deemed negligible for HAP where acute HQs are less than or equal to
one (even under the conservative assumptions of the screening
assessment), and no further analysis is performed for these HAP. In
cases where an acute HQ from the screening step is greater than 1, we
consider additional site-specific data to develop a more refined
estimate of the potential for acute impacts of concern. For all three
source categories, the acute data refinements employed consisted of
plotting the HEM-3 polar grid results for each HAP with an acute HQ
value greater than one on aerial photographs of the facilities. We then
assessed whether the highest acute HQs were off-site and at locations
that may be accessible to the public (e.g., roadways and public
buildings). These refinements are discussed more fully in the Large
Appliances Risk Assessment Report, the Fabrics and Other Textiles Risk
Assessment Report, and the Metal Furniture Risk Assessment Report,
available respectively in the Large Appliances Docket, Fabrics and
Other Textiles Docket, and Metal Furniture Docket.
4. How did we conduct the multipathway exposure and risk screening
assessment?
    The EPA conducted 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 determined
whether any sources in the source categories emitted any HAP known to
be persistent and bioaccumulative in the environment (PB-HAP), as
identified in the EPA's Air Toxics Risk Assessment Library (See Volume
1, Appendix D, at https://www2.epa.gov/fera/risk-assessment-and-modeling-air-toxics-risk-assessment-reference-library).
    For the Surface Coating of Large Appliances; the Printing, Coating,
and Dyeing of Fabrics and Other Textiles; and Surface Coating of Metal
Furniture source categories, 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 these source
categories.
5. How did we conduct the environmental risk screening assessment?
a. Adverse Environmental Effects, Environmental HAP, and Ecological
Benchmarks
    The EPA conducts a screening assessment to examine the potential
for adverse environmental effects as required under section
112(f)(2)(A) of the CAA. Section 112(a)(7) of the CAA defines ``adverse
environmental effect'' as ``any significant and widespread adverse
effect, which may reasonably be anticipated, to wildlife, aquatic life,
or other natural resources, including adverse impacts on populations of
endangered or threatened species or significant degradation of
environmental quality over broad areas.''
    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, mercury (both inorganic mercury and methyl mercury), and lead
compounds. The acid gases included in the screening assessment are 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, were 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 Large Appliances Risk
Assessment Report, the Fabrics and Other Textiles Risk Assessment
Report, and the Metal Furniture Risk Assessment Report, in the Large
Appliances Docket, Fabrics and Other Textiles Docket, and Metal
Furniture Docket, respectively.
b. Environmental Risk Screening Methodology
    For the environmental risk screening assessment, the EPA first
determined whether any facilities in the Surface Coating of Large
Appliances; Printing, Coating, and Dyeing of Fabrics and Other
Textiles; and Surface Coating of Metal Furniture source categories
emitted any of the environmental HAP. For the Surface Coating of Large
Appliances source category, we identified emissions of HCl and HF. No
environmental HAP were emitted from the other two source categories.
    Because one or more of the environmental HAP evaluated are emitted
by at least one facility in the Surface Coating of Large Appliances

source category, we proceeded to the second step of the evaluation for
that source category.
c. 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 HCl and HF. 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 potential adverse
environmental effects (as defined in section 112(a)(7) of the CAA) from
emissions of HCl and HF, 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 km\2\; 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
Large Appliances Risk Assessment Report in the Large Appliances Docket.
6. How did we conduct facility-wide assessments?
    To put the source category risks in context, we typically examine
the risks from the entire ``facility,'' where the facility includes all
HAP-emitting operations within a contiguous area and under common
control. In other words, we examine the HAP emissions not only from the
source category emission points of interest, but also emissions of HAP
from all other emission sources at the facility for which we have data.
For this source category, we conducted the facility-wide assessment
using a dataset compiled from the 2014 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 categories 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 Large Appliances
Risk Assessment Report, the Fabrics and Other Textiles Risk Assessment
Report, and the Metal Furniture Risk Assessment Report, available
respectively in the Large Appliances Docket, Fabrics and Other Textiles
Docket, and Metal Furniture Docket, provide 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 did 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 datasets, 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 Large Appliances Risk Assessment
Report, the Fabrics and Other Textiles Risk Assessment Report, and the
Metal Furniture Risk Assessment Report, available respectively in the
Large Appliances Docket, Fabrics and Other Textiles Docket, and Metal
Furniture Docket. 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 Datasets
    Although the development of the RTR emissions datasets 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 maximum individual risks 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 Cancer Guidelines \16\; namely, that ``the
primary goal of EPA actions is protection of human health; accordingly,
as an Agency policy, risk assessment procedures, including default
options that are used in the absence of scientific data to the
contrary, should be health protective'' (EPA's 2005 Cancer Guidelines,
pages 1-7). This is the approach followed here as summarized in the
next paragraphs.
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    \16\ Guidelines for Carcinogen Risk Assessment, EPA/630/P-03/
001F, March 2005. (https://www.epa.gov/risk/guidelines-carcinogen-risk-assessment).
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    Cancer UREs used in our risk assessments are those that have been
developed to generally provide an upper bound estimate of risk. That
is, they represent a ``plausible upper limit to the true value of a
quantity'' (although this is usually not a true statistical confidence
limit).\17\ In some circumstances, the true risk could be as low as
zero; however, in other circumstances the risk could be greater.\18\
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 \19\ 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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    \17\ IRIS glossary (https://ofmpub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&glossaryName=IRIS%20Glossary).
    \18\ 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.
    \19\ U.S. EPA, 1993. Reference Dose (RfC); Description and Use
in Health Risk Assessments. (https://www.epa.gov/iris/reference-dose-rfd-description-and-use-health-risk-assessments). U.S. EPA,
1994b. Methods for Derivation of Inhalation Reference Concentrations
and Application of Inhalation Dosimetry. (https://www.epa.gov/risk/methods-derivation-inhalation-reference-concentrations-and-application-inhalation-dosimetry).
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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., one 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.
    Although every effort is made to identify appropriate human health
effect dose-response values for all pollutants emitted by the sources
in this risk assessment, some HAP emitted by this source category are
lacking dose-response assessments. Accordingly, these pollutants cannot
be included in the quantitative risk assessment, which could result in
quantitative estimates understating HAP risk. To help to alleviate this
potential underestimate, where we conclude similarity with a HAP for
which a dose-response value is available, we use that value as a
surrogate for the assessment of the HAP for which no value is
available. To the extent use of surrogates indicates appreciable risk,
we may identify a need to increase priority for an IRIS assessment for
that substance. We additionally note that, generally speaking, HAP of
greatest concern due to environmental exposures and hazard are those
for which dose-response assessments have been performed, reducing the
likelihood of understating risk. Further, HAP not included in the
quantitative assessment are assessed qualitatively and considered in
the risk characterization that informs the risk management decisions,
including consideration of HAP reductions achieved by various control
options.
    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 humans
at the location of the maximum concentration. In the acute screening
assessment that we conduct under the RTR program, we assume that peak
emissions from the source category and worst-case

meteorological conditions co-occur, thus resulting in maximum ambient
concentrations. These two events are unlikely to occur at the same
time, making these assumptions conservative. We then include the
additional assumption that a person is located at this point during
this same time period. For these source categories, these assumptions
would tend to be worst-case actual exposures as it is unlikely that a
person would be located at the point of maximum exposure during the
time when peak emissions and worst-case meteorological 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. None of the three source categories in this action emit PB-
HAP, therefore, multipathway assessments were not conducted. Since no
environmental HAP are emitted from the Printing, Coating, and Dyeing of
Fabrics and Other Textiles source category or the Surface Coating of
Metal Furniture source category, an environmental risk screen was not
conducted for these categories. Small amounts of the environmental HAP,
HCl, and HF are emitted from the Surface Coating of Large Appliances
source category, therefore, an environmental risk screen was conducted.
    The environmental screening assessment relies on the outputs from
AERMOD--that estimates environmental pollutant concentrations for two
acid gases (HCl and HF). 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.\20\ 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 environmental
screening risk assessment conducted in support of RTR.
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    \20\ 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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    Input uncertainty is concerned with how accurately the models have
been configured and parameterized for the assessment at hand. 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.

IV. Analytical Results and Proposed Decisions

A. What are the analytical results and proposed decisions for the
Surface Coating of Large Appliances source category?
1. What are the results of the risk assessment and analyses?
    As described in section III of this preamble, for the Surface
Coating of Large Appliances source category, we conducted a risk
assessment for all HAP emitted. We present results of the risk