National Emission Standards for Hazardous Air Pollutants: Surface Coating of Automobiles and Light-Duty Trucks; Surface Coating of Miscellaneous Metal Parts and Products; Surface Coating of Plastic Parts and Products; 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

Federal RegisterNov 1, 2019

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2019-0314, EPA-HQ-OAR-2019-0312, EPA-HQ-OAR-2019-0313, EPA-HQ-OAR-2017-0670, EPA-HQ-OAR-2017-0668, EPA-HQ-OAR-2017-0669; FRL-9998-77-OAR]

RIN 2060-AT49 and RIN 2060-AT72

National Emission Standards for Hazardous Air Pollutants: Surface Coating of Automobiles and Light-Duty Trucks; Surface Coating of Miscellaneous Metal Parts and Products; Surface Coating of Plastic Parts and Products; 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.

SUMMARY:

The U.S. Environmental Protection Agency (EPA) is proposing amendments to address the results of the residual risk and technology reviews (RTR) that the EPA is required to conduct in accordance with the Clean Air Act (CAA) with regard to the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for the Surface Coating of Automobiles and Light-Duty Trucks (ALDT), the NESHAP for the Surface Coating of Miscellaneous Metal Parts and Products (MMPP), and the NESHAP for the Surface Coating of Plastic Parts and Products (PPP). The EPA is proposing to find the risks due to emissions of air toxics from these source categories under the current standards are acceptable and 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 analyses. The EPA is proposing to amend provisions addressing emissions during periods of startup, shutdown, and malfunction (SSM); to amend provisions regarding electronic reporting of performance test results; to amend provisions regarding monitoring requirements; and to make miscellaneous clarifying and technical corrections. This notice also proposes technical corrections to the NESHAP for Surface Coating of Large Appliances; NESHAP for Printing, Coating, and Dyeing of Fabrics and Other Textiles; and NESHAP for Surface Coating of Metal Furniture.

DATES:

Comments.

Comments must be received on or before December 16, 2019. 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 December 2, 2019.

Public hearing.

If anyone contacts us requesting a public hearing on or before November 6, 2019, 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/surface-coating-automobiles-and-light-duty-trucks-national-emission, https://www.epa.gov/stationary-sources-air-pollution/surface-coating-miscellaneous-metal-parts-and-products-national

and

https://www.epa.gov/stationary-sources-air-pollution/surface-coating-plastic-parts-and-products-national-emission. See

SUPPLEMENTARY INFORMATION

for information on requesting and registering for a public hearing.

ADDRESSES:

You may send comments, identified by Docket ID No. EPA-HQ-OAR-2019-0314 for 40 Code of Federal Regulations (CFR) part 63, subpart IIII, Automobiles and Light-Duty Trucks; Docket ID No. EPA-HQ-OAR-2019-0312 for 40 CFR part 63, subpart MMMM, Surface Coating of Miscellaneous Metal Parts and Products; Docket ID No. EPA-HQ-OAR-2019-0313 for 40 CFR part 63, subpart PPPP, Surface Coating of Plastic Parts and Products; Docket ID No. EPA-HQ-OAR-2017-0668 for 40 CFR part 63, subpart OOOO, Printing Coating, and Dyeing of Fabrics and Other Textiles; EPA-HQ-OAR-2017-0669 for 40 CFR part 63, subpart RRRR, Surface Coating of Metal Furniture; Docket ID No. EPA-HQ-OAR-2017-0670, for 40 CFR part 63 subpart NNNN for Surface Coating of Large Appliances by any of the following methods:

•

Federal eRulemaking Portal: https://www.regulations.gov/

(our preferred method). Follow the online instructions for submitting comments.

•

Email: a-and-r-docket@epa.gov.

Include Docket ID No. EPA-HQ-OAR-2019-0312, EPA-HQ-OAR-2019-0313, EPA-HQ-OAR-2019-0314, HQ-OAR-2017-0668, EPA-HQ-OAR-2017-0669, or EPA-HQ-OAR-2017-0670 (specify the applicable docket number) in the subject line of the message.

•

Fax:

(202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-2019-0312, EPA-HQ-OAR-2019-0313, or EPA-HQ-OAR-2019-0314, HQ-OAR-2017-0668, EPA-HQ-OAR-2017-0669, or EPA-HQ-OAR-2017-0670 (specify the applicable docket number).

•

Mail:

U.S. Environmental Protection Agency, EPA Docket Center, Docket ID No. EPA-HQ-OAR-2019-0312, EPA-HQ-OAR-2019-0313, or EPA-HQ-OAR-2019-0314, 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.

•

Hand/Courier Delivery:

EPA Docket Center, WJC West Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004. The Docket Center's hours of operation are 8:30 a.m.-4:30 p.m., Monday-Friday (except federal holidays).

Instructions:

All submissions received must include the applicable Docket ID No. for this rulemaking. Comments received may be posted without change to

https://www.regulations.gov/,

including any personal information provided. For detailed instructions on sending comments and additional information on the rulemaking process,

see

the

SUPPLEMENTARY INFORMATION

section of this document.

FOR FURTHER INFORMATION CONTACT:

For questions about this proposed action for the Surface Coating of Miscellaneous Metal Parts and Products (MMPP) NESHAP, the Surface Coating of Plastic Parts and Products (PPP) NESHAP, and the technical corrections to the NESHAP for Surface Coating of Large Appliances contact Ms. Kim Teal, Minerals and Manufacturing Group, Sector Policies and Programs Division (D243-04), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; telephone number: (919) 541-5580; fax number: (919) 541-4991; and email address:

teal.kim@epa.gov.

For questions about the proposed action for the Surface Coating of Automobiles and Light-Duty Trucks (ALDT) NESHAP and the technical corrections to the NESHAP for Surface Coating of Metal Furniture contact Ms. J. Kaye Whitfield, Minerals and Manufacturing Group, Sector Policies and Programs Division (D243-04), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; telephone number: (919) 541-2509; fax number: (919) 541-4991; and email address:

whitfield.kaye@epa.gov.

For questions about the technical corrections to the Printing, Coating, and Dyeing of Fabrics and Other Textiles contact Ms. Paula

Hirtz, Minerals and Manufacturing Group, Sector Policies and Programs Division (D243-04), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; telephone number: (919) 541-2618; fax number: (919) 541-4991; and email address:

hirtz.paula@epa.gov.

For specific information regarding the risk modeling methodology, contact Mr. Chris Sarsony, Health and Environmental Impacts Division (C539-02), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; telephone number: (919) 541-4843; fax number: (919) 541-0840; and email address:

sarsony.chris@epa.gov.

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: (202) 564-1395; and email address:

cox.john@epa.gov.

For questions about monitoring and testing requirements, contact Mr. Muntasir Ali, Measurement Policy Group, Sector Policies and Programs Division (D221-01), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; telephone number: (919) 541-0833; fax number: (919) 541-4991; and email address:

ali.muntasir@epa.gov.

SUPPLEMENTARY INFORMATION:

Public hearing.

Please contact Ms. Nancy Perry at (919) 541-5628 or by email at

perry.nancy@epa.gov

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.

Docket.

The EPA has established three separate dockets for these rulemakings. Docket ID No. EPA-HQ-OAR-2019-0314 has been established for 40 CFR part 63, subpart IIII, Surface Coating of Automobiles and Light-Duty Trucks. Docket ID No. EPA-HQ-OAR-2019-0312 has been established for 40 CFR part 63, subpart MMMM, Surface Coating of Miscellaneous Metal Parts and Products. EPA-HQ-OAR-2019-0313 has been established for 40 CFR part 63, subpart PPPP, Surface Coating of Plastic Parts and Products. In addition, docket numbers for the technical corrections have been established: Docket ID No. EPA-HQ-OAR-2017-0670 for 40 CFR part 63, subpart NNNN, Surface Coating of Large Appliances; Docket ID No. EPA-HQ-OAR-2017-0669 for 40 CFR part 63, subpart RRRR, Surface Coating of Metal Furniture; and Docket ID No. EPA-HQ-OAR-2017-0668 for 40 CFR part 63, subpart OOOO, Printing, Coating, and Dyeing of Fabrics and Other Textiles. All documents in the dockets are listed in

Regulations.gov

. Although listed, some information is not publicly available,

e.g.,

Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy. Publicly available docket materials are available either electronically in

Regulations.gov

or in hard copy at the EPA Docket Center, Room 3334, 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 (202) 566-1744, and the telephone number for the EPA Docket Center is (202) 566-1742.

The dockets related to the technical corrections to the NESHAP for Surface Coating of Large Appliances, the NESHAP for Printing, Coating, and Dyeing of Fabrics and Other Textiles, and the NESHAP for Surface Coating of Metal Furniture are discussed in section II.E of this preamble.

Instructions.

Direct your comments to Docket ID No. EPA-HQ-OAR-2019-0314 for 40 CFR part 63, subpart IIII, Surface Coating of Automobiles and Light-Duty Trucks, Docket ID No. EPA-HQ-OAR-2019-0312 for 40 CFR part 63, subpart MMMM, Surface Coating of Miscellaneous Metal Parts and Products, or Docket ID No. EPA-HQ-OAR-2019-0313 for 40 CFR part 63, subpart PPPP, Surface Coating of Plastic Parts and Products, as applicable to your comments. Direct your comments for the technical corrections to Docket ID No. EPA-HQ-OAR-2017-0670 for 40 CFR part 63, subpart NNNN, Surface Coating of Large Appliances; Docket ID No. EPA-HQ-OAR-2017-0669 for 40 CFR part 63, subpart RRRR, Surface Coating of Metal Furniture; and Docket ID No. EPA-HQ-OAR-2017-0668 for 40 CFR part 63, subpart OOOO, Printing, Coating, and Dyeing of Fabrics and Other Textiles. 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 below.

The EPA may publish any comment received to its public docket. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission (

i.e.,

on the Web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit

https://www.epa.gov/dockets/commenting-epa-dockets.

The

https://www.regulations.gov/

website allows you to submit your comment anonymously, which means the EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an email comment directly to the EPA without going through

https://www.regulations.gov/,

your email address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the internet. If you submit an electronic comment, the EPA recommends that you include your name and other contact information in the body of your comment and with any digital storage media you submit. If the EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, the EPA may not be able to consider your comment. Electronic files should not include special characters or any form of encryption and be free of any defects or viruses. For additional information about the EPA's public docket, visit the EPA Docket Center homepage at

https://www.epa.gov/dockets.

Submitting CBI.

Do not submit information containing CBI to the EPA through

https://www.regulations.gov/

or email. Clearly mark the part or all of the information that you claim to be CBI. For CBI information on any digital storage media that you mail to the EPA, mark the outside of the digital storage media as CBI and then identify electronically within the digital storage media the specific information that is claimed as CBI. In addition to one complete version of the comments that includes information claimed as CBI, you must submit a copy of the

comments that does not contain the information claimed as CBI directly to the public docket through the procedures outlined in

Instructions

above. If you submit any digital storage media that does not contain CBI, mark the outside of the digital storage media clearly that it does not contain CBI. Information not marked as CBI will be included in the public docket and the EPA's electronic public docket without prior notice. Information marked as CBI will not be disclosed except in accordance with procedures set forth in 40 CFR part 2. Send or deliver information identified as CBI only to the following address: OAQPS Document Control Officer (C404-02), OAQPS, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, Attention Docket ID No. EPA-HQ-OAR-2019-0314 for 40 CFR part 63, subpart IIII, Surface Coating of Automobiles and Light-Duty Trucks (ALDT Docket); Docket ID No. EPA-HQ-OAR-2019-0312 for 40 CFR part 63, subpart MMMM, Surface Coating of Miscellaneous Metal Parts and Products (MMPP Docket); and Docket ID No. EPA-HQ-OAR-2019-0313 for 40 CFR part 63, subpart PPPP, Surface Coating of Plastic Parts and Products (PPP Docket), as applicable.

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

ALDT automobile and light-duty truck

BACT best available control technology

CAA Clean Air Act

CalEPA California EPA

CBI Confidential Business Information

CDX Central Data Exchange

CEDRI Compliance and Emissions Data Reporting Interface

CEMS continuous emissions monitoring systems

CFR Code of Federal Regulations

ECHO Enforcement and Compliance History Online

EPA Environmental Protection Agency

EPFP extreme performance fluoropolymer

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

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

MIBK methyl isobutyl ketone

MIR maximum individual risk

MMPP miscellaneous metal parts and products

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

POM polycyclic organic matter

PPP plastic parts and products

PRA Paperwork Reduction Act

PTE permanent total enclosure

RACT reasonably available control technology

RBLC RACT/BACT/LAER Clearinghouse

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

µg/m

micrograms per cubic meter

UMRA Unfunded Mandates Reform Act

URE unit risk estimate

VCS voluntary consensus standards

VOC volatile organic compounds

Organization of this document.

The information in this preamble is organized as follows:

I. General Information

A. Does this action apply to me?

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

II. Background

A. What is the statutory authority for this action?

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

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

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

III. Analytical Procedures and Decision-Making

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

B. How do we perform the technology review?

C. How 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 automobiles and light-duty trucks source category?

B. What are the analytical results and proposed decisions for the MMPP source category?

C. What are the analytical results and proposed decisions for the Surface Coating of Plastic Parts and Products source category?

D. Proposed Corrections to Earlier Subparts.

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), the Surface Coating of Automobiles and Light-Duty Trucks (ALDT) source category includes any facility that is a major source of hazardous air pollutants (HAP) and is engaged in the surface coating of new automobile or new light-duty truck bodies or body parts for new automobiles or new light-duty trucks. We estimate that 43 major source facilities engaged in surface coating of automobiles and light-duty trucks would be subject to this proposal. The MMPP source category includes any facility engaged in the surface coating of miscellaneous metal parts and products that is a major source of HAP emissions. Miscellaneous metal parts and products include, but are not limited to, metal components of the following types of products as well as the products themselves: Motor vehicle parts and accessories; bicycles and sporting goods; recreational vehicles; extruded aluminum structural components; railroad cars; heavy-duty trucks; medical equipment; lawn and garden equipment; electronic equipment; magnet wire; steel drums; industrial machinery; metal pipes; and numerous other industrial, household, and consumer products. We estimate that 368 major source facilities engaged in surface coating of miscellaneous metal parts and products would be subject to this proposal. The PPP source category includes any facility engaged in the surface coating of plastic parts or products that is a major source of HAP emissions. Plastic parts and products include, but are not limited to, plastic components of the following types of products as well as the products themselves: Motor vehicle parts and accessories for automobiles, trucks, recreational vehicles; sporting and recreational goods; toys; business machines; laboratory and medical equipment; and household and other consumer products. We estimate that 125 major source facilities engaged in plastic parts and products surface coating would be subject to this proposal.

Table 1—NESHAP, Industrial and Government Sources Affected by This Proposed Action

NESHAP source

category

NAICS code

Regulated entities

Surface Coating of Automobiles and Light-Duty Trucks

336111, 336112, 336211

Automobile and light-duty truck assembly plants, producers of automobile and light-duty truck bodies.

Surface Coating of Miscellaneous Metal Parts and Products

335312, 336111, 336211, 336312, 33632, 33633, 33634, 33637, 336399

Automobile parts (engine parts, vehicle parts and accessories, brakes, axles, etc.).

331316, 331524, 332321, 332323

Extruded aluminum, architectural components, rod, and tubes.

33312, 333611, 333618

Heavy equipment (tractors, earth moving machinery).

332312, 332722, 332813, 332991, 332999, 334119, 336413, 339999

Job shops (making any of the products from the miscellaneous metal parts and products segments).

33612, 336211

Large trucks and buses.

331319, 331422, 335929

Magnet wire.

332311

Prefabricated metal buildings, carports, docks, dwellings, greenhouses, panels for buildings.

33242, 81131, 322214, 326199, 331513, 332439

Metal drums, kegs, pails, shipping containers.

331111, 33121, 331221, 331511

Metal pipe and foundry (plate, tube, rods, nails, spikes, etc.).

33651, 336611, 482111

Rail transportation (brakes, engines, freight cars, locomotives.

3369, 331316, 336991, 336211, 336112, 336213, 336214, 336399

Recreational vehicles (motorcycles, motor homes, semitrailers, truck trailers).

326291, 326299

Rubber to metal products (engine mounts, rubberized tank tread, harmonic balancers.

332311, 332312

Structural steel (joists, railway bridge sections, highway bridge sections).

336212, 336999, 33635, 56121, 8111. 56211

Miscellaneous transportation related equipment and parts.

Surface Coating of Plastic Parts and Products

337214

32614, 32615

Office furniture, except wood.

Plastic foam products (

e.g.,

pool floats, wrestling mats, life jackets).

326199

Plastic products not elsewhere classified (

e.g.,

name plates, coin holders, storage boxes, license plate housings, cosmetic caps, cup holders).

333313

Office machines.

33422

Radio and television broadcasting and communications equipment (

e.g.,

cellular telephones).

336211

Motor vehicle body manufacturing.

336399

Motor vehicle parts and accessories.

336212

Truck trailer manufacturing.

336213

Motor home manufacturing.

336214

Travel trailer and camper manufacturing.

336999

Transportation equipment not elsewhere classified (

e.g.,

snowmobile hoods, running boards, tractor body panels, personal watercraft parts).

339111, 339112

Medical equipment and supplies.

33992

Sporting and athletic goods.

33995

Signs and advertising specialties.

339999

Manufacturing industries not elsewhere classified (

e.g.,

bezels, consoles, panels, lenses).

North American Industry Classification System.

Regulated entities means major source facilities that apply surface coatings to these parts or products.

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

and

https://www.epa.gov/stationary-sources-air-pollution/surface-coating-plastic-parts-and-products-national-emission.

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 are available in the Automobiles and Light-Duty Trucks, the Metal Parts and Products, and the Plastic Parts and Products Dockets (Docket ID No. EPA-HQ-OAR-2019-0314, Docket ID No. EPA-HQ-OAR-2019-0312, and Docket ID No. EPA-HQ-OAR-2019-0313, respectively).

II. Background

A. What is the statutory authority for this action?

The statutory authority for this action is provided by sections 112 and 301 of the CAA, as amended (42 U.S.C. 7401

et seq.

Section 112 of the CAA establishes a two-stage regulatory process to develop standards for emissions of HAP from stationary sources. Generally, the first stage involves establishing technology-based standards and the second stage involves evaluating those standards that are based on 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 8 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 (Docket ID No. EPA-HQ-OAR-2019-0314 for Automobiles and Light-Duty Trucks, Docket ID No. EPA-HQ-OAR-2019-0312 for Miscellaneous Metal Parts and Products, and Docket ID No. EPA-HQ-OAR-2019-0313 for Plastic Parts and Products).

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 CAA.

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). For source categories subject to MACT standards, section 112(f)(2) of the CAA requires the EPA to determine whether promulgation of additional standards is needed to provide an ample margin of safety to protect public health or to prevent an adverse environmental effect. Section 112(d)(5) of the CAA provides that this residual risk review is not required for categories of area sources subject to GACT standards. Section 112(f)(2)(B) of the CAA further expressly preserves the EPA's use of the two-step approach for developing standards to address any residual risk and the Agency's interpretation of “ample margin of safety” developed in the

National Emissions Standards for Hazardous Air Pollutants: Benzene Emissions from Maleic Anhydride Plants, Ethylbenzene/Styrene Plants, Benzene Storage Vessels, Benzene Equipment Leaks, and Coke By-Product Recovery Plants

(Benzene NESHAP) (54 FR 38044, September 14, 1989). The EPA notified Congress in the 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

EPA,

529 F.3d 1077, 1083 (D.C. Cir. 2008).

The approach incorporated into the CAA and used by the EPA to evaluate residual risk and to develop standards under CAA section 112(f)(2) is a two-step approach. In the first step, the EPA determines whether risks are acceptable. This determination “considers all health information, including risk estimation uncertainty, and includes a presumptive limit on maximum individual lifetime [cancer] risk (MIR)

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 to protect public health “in consideration of all health information, including the number of persons at risk levels higher than approximately [1-in-1 million], as well as other relevant factors, including costs and economic impacts, technological feasibility, and other factors relevant to each particular decision.”

Id.

The EPA must promulgate emission standards necessary to provide an ample margin of safety to protect public health or determine that the standards being reviewed provide an ample margin of safety without any revisions. After conducting the ample margin of safety analysis, we consider whether a more stringent standard is necessary to prevent, taking into consideration costs, energy, safety, and other relevant factors, an adverse environmental effect.

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 8 years. In conducting this review, which we call the “technology review,” the EPA is not required to recalculate the MACT floor.

Natural Resources Defense Council (NRDC)

EPA,

529 F.3d 1077, 1084 (D.C. Cir. 2008).

Association of Battery Recyclers, Inc.

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 automobiles and light-duty trucks source category and how does the current NESHAP regulate its HAP emissions?

a. Source Category Description

The NESHAP for the ALDT source category was promulgated on April 26, 2004 (69 FR 22602), and is codified at 40 CFR part 63, subpart IIII. Technical corrections and clarifying amendments were promulgated on December 22, 2006 (71 FR 76922) and April 24, 2007 (72 FR 20227). The ALDT NESHAP applies to any coating operations which apply topcoats to new automobile or new light-duty truck bodies or body parts for new automobiles or new light-duty trucks and/or coatings to new other motor vehicle bodies or body parts for new other motor vehicles; parts intended for use in new automobiles, new light-duty trucks, or new other motor vehicles; or aftermarket repair or replacement parts for automobiles, light-duty trucks, or other motor vehicles; and the affected source is located at a facility that is a major source, is located at a major source, or is part of a major source of emissions of HAP (40 CFR 63.3081). The ALDT NESHAP (40 CFR 63.3176) defines an “automobile” as “a motor vehicle designed to carry up to eight passengers, excluding vans, sport utility vehicles, and motor vehicles designed primarily to transport light loads of property,” and “light-duty truck” as “vans, sport utility vehicles, and motor vehicles designed primarily to transport light loads of property with gross vehicle weight rating of 8,500 lbs [pounds] or less.”

The ALDT 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, primers, deadeners, and maskants. Decorative, protective, or functional materials that consist only of protective oils for metal, acids, bases, or any combination of these substances are not considered coatings for the purposes of this subpart.” (40 CFR 63.3176).

The ALDT NESHAP does not apply to a surface coating operation that is subject to any other NESHAP as of June 25, 2004, except when a source chooses to comply with the ALDT NESHAP instead of the MMPP NESHAP (40 CFR part 63, subpart MMMM) or the PPP NESHAP (40 CFR part 63, subpart PPPP). (40 CFR 63.3082(c).)

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 (

echo.epa.gov)

and a review of active air emissions permits, we estimate that 43 facilities are subject to the ALDT NESHAP. A complete list of facilities subject to the ALDT NESHAP is available in Table 1 of Appendix 10 to the memorandum titled

Residual Risk Assessment for the Surface Coating of Automobiles and Light-duty Trucks Source Category in Support of the 2019 Risk and Technology Review Proposed Rule (

hereafter referred to as the

Automobiles and Light-Duty Trucks Risk Assessment Report),

in the ALDT Docket (Docket ID No. EPA-HQ-OAR-2019-0314).

b. HAP Emission Sources

The primary HAP emitted from ALDT surface coating operations are organic HAP and included toluene, xylene, glycol ethers, methyl isobutyl ketone (MIBK), ethyl benzene, and methanol. The HAP emissions are from coating application and drying and curing ovens in the ALDT surface coating operations. Some emissions occur from the cleaning of spray booths and equipment. In most cases, HAP emissions from surface preparation, storage and handling are relatively small (

i.e.,

not quantifiable) for this source category.

Inorganic (metal) HAP emissions were considered in the development of the ALDT NESHAP and the EPA determined that, although very low levels of emissions were reported in coatings, no inorganic HAP are emitted. Based on data obtained during development of the 2004 proposed NESHAP (67 FR 78612, December 24, 2002), some coatings in the ALDT source category reported emissions of inorganic HAP that likely were not emitted due to coating application techniques used. Instead, the 2004 proposed NESHAP found that the inorganic HAP components of the coatings mostly remained as solids in the dry coating film on the parts being coated, were collected by the circulating water under the spray booth floor grates, or were deposited on the walls, floor, and grates of the spray booths and other equipment in which they are applied. More recent data from the 2011 NEI data, used to inform this RTR, show total reported source category inorganic HAP emissions of 0.008 tpy from antimony, chromium, manganese, and nickel, and no reported emissions of inorganic HAP in thinners or cleaning

materials. (See Appendix 1 to the

Automobiles and Light-Duty Trucks Risk Assessment Report,

in the ALDT Docket). Based on feedback from industry and information gleaned from EPA site visits, facilities in the ALDT source category employ high-efficiency spray equipment (including robotic spraying) to minimize the overall amount of coating used, thereby reducing inorganic HAP emissions further. Therefore, we conclude that, although inorganic HAP are reported components of coatings, no inorganic HAP are emitted.

c. Current NESHAP Requirements for Control of HAP

The NESHAP specifies numerical limits for the organic HAP emissions from both existing sources and new or reconstructed sources. These emissions limits are established for each of several process groupings at the source including (1) electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive operations plus all coatings and thinners, except for deadener materials and for adhesive and sealer materials that are not components of glass bonding systems, used in coating operations; (2) primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive operation plus all coatings and thinners, except for deadener materials and for adhesive and sealer materials that are not components of glass bonding systems, used in coating operations; (3) adhesives and sealers, other than glass bonding adhesive materials; and (4) deadener materials.

The specific organic HAP emission limits are summarized in Table 2 of the memorandum titled

Technology Review for Surface Coating Operations in the Automobiles and Light-Duty Trucks Source Category

in the ALDT Docket.

Compliance with the ALDT NESHAP emission limits can be achieved using several different options, including a compliant material option, an emission rate without add-on controls option (averaging option), and an emission rate with add-on controls option. For bake ovens used to cure electrodeposition primers, an alternative is to capture the emissions and duct them to a control device having a destruction or removal efficiency of at least 95 percent. 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. Facilities that have multiple paint lines may choose to group operations from two or more paint lines together, or to make a separate grouping of the operations from individual paint lines. Operating limits may apply for facilities that use an emission capture and control system to reduce emissions.

If the facility uses the emission rate with add-on controls option, they must develop and implement a work practice plan to minimize organic HAP emissions from all processes associated with the coating operations (

i.e.,

storage; mixing and conveying of coatings; thinners; cleaning materials; and waste materials). 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 surface coating of miscellaneous metal parts and products source category and how does the current NESHAP regulate its HAP emissions?

a. Source Category Description

The MMPP NESHAP was promulgated on January 2, 2004 (69 FR 130), and is codified at 40 CFR part 63, subpart MMMM. A technical correction to the final rule was published on April 26, 2004 (69 FR 22602) and December 22, 2006 (71 FR 76922). The MMPP NESHAP applies to owners or operators of metal parts and products surface coating operations at facilities that are major sources of HAP.

Miscellaneous metal parts and products include, but are not limited to, metal components of the following types of products as well as the products themselves: motor vehicle parts and accessories, bicycles and sporting goods, recreational vehicles, extruded aluminum structural components, railroad cars, heavy-duty trucks, medical equipment, lawn and garden equipment, electronic equipment, magnet wire, steel drums, industrial machinery, metal pipes, and numerous other industrial, household, and consumer products. The MMPP NESHAP (40 CFR 63. 3881(c)) does not apply to the surface coating or coating operations that meet the applicability criteria of eleven other surface coating NESHAP,

e.g.,

surface coating of metal components of wood furniture (subpart JJ of 40 CFR part 63), surface coating of metal components of large appliances (subpart NNNN of 40 CFR part 63), and surface coating of metal components of automobiles and light-duty trucks (subpart IIII of 40 CFR part 63).

Based on our search of the NEI and the EPA's ECHO database and a review of active air emission permits, we estimate that 368 facilities are subject to the MMPP NESHAP. A list of facilities we identified as subject to the MMPP NESHAP is available in Table 1 to Appendix 10 to the memorandum titled

Residual Risk Assessment for the Surface Coating of Miscellaneous Metal Parts and Products Source Category in Support of the 2019 Risk and Technology Review Proposed Rule

(hereafter referred to as the

Miscellaneous Metal Parts and Products Risk Assessment Report

), in the MMPP Docket (Docket ID No. EPA-HQ-OAR-2019-0312).

b. HAP Emission Sources

The primary HAP emitted from MMPP surface coating operations are organic HAP and include xylenes, toluene, glycol ethers, ethyl benzene, MIBK, methanol, ethylene glycol, and dimethyl phthalate. The majority of organic HAP emissions can be attributed to the application, drying, and curing of coatings.

Inorganic HAP emissions were considered in the development of the MMPP NESHAP and the EPA determined that inorganic HAP emissions would be very low based on the coating application techniques in place at the time of the rule development. Based on information reported in survey responses during the development of the proposal for the 2004 NESHAP, inorganic HAP, including chromium, cobalt, lead, and manganese compounds, are components of some coatings used by this source category. Inorganic HAP in the coatings would only have the potential to be emitted if they were spray-applied, but the inorganic HAP would be either deposited on the part being coated as part of the surface coating, on the walls and floors of the spray booth, or captured by the spray booth filters (typically either a dry fabric filter or a water-wash filter system). No inorganic HAP were documented in thinners or cleaning materials. Emissions would be further reduced by the use of high efficiency spray equipment, often combined with robotic spraying, that minimize the amount of coating that is sprayed. For more detailed information please see the emissions memorandum in Appendix 1 to the

Miscellaneous Metal Parts and Products Risk Assessment Report,

in the MMPP Docket.

In response to comments on the 2004 proposed NESHAP,

the EPA argued

that given the combination of very low usage of coatings containing inorganic HAP in this source category, and the current and expected continued use of controls (dry filters and waterwash systems on spray booths and high efficiency equipment) to reduce overspray emissions, the EPA believed that levels of inorganic HAP emissions did not warrant federal regulation because those regulations would not be expected to result in additional emissions reduction.

Surface Coating of Miscellaneous Metal Parts and Products, Summary of Public Comments and

Responses on Proposed Rule.

August 2003. EPA-453/R-03-008; p. 83.

c. Current NESHAP Requirements for Control of HAP

The MMPP NESHAP establishes the organic HAP emissions limits for new and existing sources. The final rule contains five subcategories: (1) General use coating, (2) high performance coating, (3) magnet wire coating, (4) rubber-to-metal coating, and (5) extreme performance fluoropolymer coating (EPFP).

Compliance can be demonstrated with using a variety of compliance options including, (1) a compliant coatings option, where all coatings used have organic HAP contents that individually meet the organic HAP emissions limit, and all thinners and cleaning materials contain no organic HAP; (2) an emission rate without add-on controls option, where the organic HAP emission rate, calculated as a rolling 12-month emission rate and determined on a monthly basis, is equal to or less than the organic HAP emissions limit; or (3) an emission rate with add-on controls option, where the organic HAP emission rate, calculated as a rolling 12-month emissions rate and determined on a monthly basis, taking into account the emissions reduction achieved through the use of one or more emissions capture and control devices, is equal to or less than the organic HAP emissions limit. A facility using the add-on control option must also comply with work practice standards to minimize organic HAP emissions from the storage, mixing, and conveying of coatings, thinners, cleaning materials, and waste materials associated with the coating operation(s) and must also comply with operating limits for the emissions capture systems and add-on control devices.

If a facility's surface coating operations meet the applicability criteria of more than one of the coating subcategories in the MMPP NESHAP, the facility may comply separately with each emissions limit or comply using one of the following options:

• If general use coating or magnet wire coating constitute 90 percent or more of the surface coating activity at the facility (

i.e.,

it is the predominant activity), then the facility can comply with that one emissions limit for all surface coating at the facility.

• The facility can comply with a facility-specific emissions limit calculated on the basis of the applicable emissions limits and the amount of coating activity performed in each coating subcategory, where activity is measured as the volume of coating solids used.

The specific organic HAP emission limits for each coating subcategory and the operating limits are summarized in Tables 4 and 5 of the memorandum titled

Technology Review for Surface Coating Operations in the Miscellaneous Metal Parts and Products Category.

3. What is the surface coating of plastic parts and products source category and how does the current NESHAP regulate its HAP emissions?

a. Source Category Description

The NESHAP for the PPP source category was promulgated on April 19, 2004 (69 FR 20968), and is codified at 40 CFR part 63, subpart PPPP. Technical corrections to the final rule were published on December 22, 2006 (71 FR 76922) and April 24, 2007 (72 FR 20227). The PPP NESHAP applies to owners or operators of PPP surface coating operations at facilities that are major sources of HAP. Plastic parts and products include, but are not limited to, plastic components of the following types of products as well as the products themselves: Motor vehicle parts and accessories for automobiles, trucks, recreational vehicles; sporting and recreational goods; toys; business machines; laboratory and medical equipment; and household and other consumer products. The PPP NESHAP (40 CFR 63. 4481(c)) does not apply to the surface coating or coating operations of items that meet the applicability criteria of eleven other surface coating NESHAP,

e.g.,

surface coating of plastic components of wood furniture (subpart JJ of 40 CFR part 63), surface coating of plastic components of large appliances (subpart NNNN of 40 CFR part 63), and surface coating of plastic components of automobiles and light-duty trucks (subpart IIII of 40 CFR part 63).

Based on our search of the NEI and the EPA's ECHO database and a review of active air emission permits, we estimate that 125 facilities are subject to the PPP NESHAP. A list of facilities we identified as subject to the PPP NESHAP is available in Table 1 to Appendix 10 to the memorandum titled

Residual Risk Assessment for the Surface Coating of Plastic Parts and Products Source Category in Support of the 2019 Risk and Technology Review Proposed Rule

(hereafter referred to as the

Plastic Parts and Products Risk Assessment Report

), in the PPP Docket (Docket ID No. EPA-HQ-OAR-2019-0313).

b. HAP Emission Sources

The primary HAP emitted from PPP surface coating operations are organic HAP and, based on the 2011 NEI, include xylene, toluene, MIBK, ethylbenzene, styrene, glycol ethers, and methanol, in order of decreasing emissions. These compounds account for about 96 percent of the nationwide HAP emissions from this source category, based on an analysis of the NEI.

No inorganic HAP are currently associated with the coatings used in this source category, based on the data in the NEI.

c. Current NESHAP Requirements for Control of HAP

The PPP NESHAP specifies numerical emission limits for existing sources and for new and reconstructed sources for organic HAP emissions. The final rule contains four subcategories: (1) General use coating, (2) thermoplastic olefin coating, (3) automotive lamp coating, and (4) assembled on-road vehicle coating.

Compliance can be demonstrated with a variety of compliance options including, (1) a compliant material option, where the HAP content of each coating used is less than or equal to the applicable organic HAP emissions limit and each thinner, additive, and cleaning material uses no organic HAP; (2) an emission rate without add-on controls option, where the organic HAP emission rate, calculated as a rolling 12-month emission rate and determined on a monthly basis, is equal to or less than the organic HAP emissions limit; or (3) an emission rate with add-on controls option, where the organic HAP emission rate, calculated as a rolling 12-month emissions rate and determined on a monthly basis, taking into account the emissions reduction achieved through the use of one or more emissions capture and control devices, is equal to or less than the organic HAP emissions limit. A facility using the add-on control option must also comply with work practice standards to minimize organic HAP emissions from the storage, mixing, and conveying of coatings, thinners, cleaning materials, and waste materials associated with the coating operation(s) and must also comply with

operating limits for the emissions capture systems and add-on control devices.

The specific organic HAP emission limits for each coating subcategory are summarized in Table 2 of the memorandum titled

Technology Review for Surface Coating Operations in the Plastic Parts and Products Category.

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 3 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. Detailed information on the development of the modeling file for the ALDT source category can be found in Appendix 1 to the

Automobiles and Light-Duty Trucks Risk Assessment Report,

in the ALDT Docket (Docket ID No. EPA-HQ-OAR-2017-0314). Detailed information on the development of the modeling file for the MMPP source category can be found in Appendix 1 to the

Miscellaneous Metal Parts and Products Risk Assessment Report,

in the MMPP Docket (Docket ID No. EPA-HQ-OAR-2019-0312). Detailed information on the development of the modeling file for the PPP source category can be found in Appendix 1 to the

Plastic Parts and Products Risk Assessment Report,

in the PPP Docket (Docket ID No. EPA-HQ-OAR-2019-0313).

For each risk modeling and technology review portion of these three 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 for many, but not all, of the facilities in each source category. 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 industry associations and facility owners or operators to confirm and clarify the sources of emissions that were reported in the NEI.

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. For many sources in the MMPP source category in the rubber-to-metal bonding and the high-performance coating subcategories, we also reviewed recent semi-annual compliance reports to confirm the compliance option they were using and the emission rates they were achieving.

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).

This database 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, an NSR permit must be obtained if a facility is planning new construction that increases the air emissions of any regulated NSR pollutant at or above 100 or 250 tpy (could be a lower threshold depending upon nonattainment severity) or a modification that results in a significant emissions increase and a significant net emissions increase of any regulated NSR pollutant (“significant” emissions increase is defined in the NSR regulations and is pollutant-specific, ranging from less than 1 pound (lb) to 100 tpy of the applicable regulated NSR pollutant). 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.

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 Automobiles and Light-Duty Trucks Category,

July 2019 (hereafter referred to as the

Automobiles and Light-Duty Trucks Technology Review Memo

Technology Review for the Surface Coating Miscellaneous Metal Parts and Products Source Category,

July 2019 (hereafter referred to as the

Miscellaneous Metal Parts and Products Technology Review Memo

), and

Technology Review for Surface Coating Operations in the Plastic Parts and Products Category,

July 2019 (hereafter referred to as the

Plastic Parts and Products Technology Review Memo

), available in the respective ALDT, MMPP, and PPP Dockets.

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

As part of the technology review for the ALDT, the MMPP, and the PPP NESHAP source categories, we reviewed information available in the American Coatings Association's (ACA)

Industry Market Analysis,

9th Edition (2014—2019).

The

ACA Industry Market Analysis

provided information on trends in coatings technology that can affect emissions from the ALDT, the MMPP, and the PPP source categories. Additional details regarding our review of these information sources are contained in the

Automobiles and Light-Duty Trucks Technology Review Memo, Miscellaneous Metal Parts and Products Technology Review Memo,

and the Plastic Parts and Products

Technology Review Memo,

available in the respective ALDT, MMPP, and PPP Dockets.

Prepared for the ACA, Washington, DC, by The ChemQuest Group, Inc., Cincinnati, Ohio. 2015.

III. Analytical Procedures and Decision-Making

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.

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:

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

“[t]he policy chosen by the Administrator permits consideration of multiple measures of health risk. Not only can the MIR figure be considered, but also incidence, the presence of non-cancer health effects, and the uncertainties of the risk estimates. In this way, the effect on the most exposed individuals can be reviewed as well as the impact on the general public. These factors can then be weighed in each individual case. 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 10 thousand should ordinarily be the upper end of the range of acceptability. As risks increase above this benchmark, they become presumptively less acceptable under CAA section 112, and would be weighed with the other health risk measures and information in making an overall judgment on acceptability. Or, the Agency may find, in a particular case, that a risk that includes MIR less than the presumptively acceptable level is unacceptable in the light of other health risk factors.”

Id.

at 38045. In other words, risks that include an MIR above 100-in-1 million may be determined to be acceptable, and risks with an MIR below that level may be determined to be unacceptable, depending on all of the available health information. Similarly, with regard to the ample margin of safety analysis, the EPA stated in the Benzene NESHAP that: “EPA believes the relative weight of the many factors that can be considered in selecting an ample margin of safety can only be determined for each specific source category. This occurs mainly because technological and economic factors (along with the health-related factors) vary from source category to source category.”

Id.

at 38061. We also consider the uncertainties associated with the various risk analyses, as discussed earlier in this preamble, in our determinations of acceptability and ample margin of safety.

The EPA notes that it has not considered certain health information to date in making residual risk determinations. At this time, we do not attempt to quantify 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.”

Recommendations of the SAB Risk and Technology Review Methods Panel are provided in their report, which is available at:

http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.

In response to the SAB recommendations, the EPA is incorporating cumulative risk analyses into its RTR risk assessments, including those reflected in this proposal. 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 HQs from all noncarcinogens affecting the same target organ system.

Although we are interested in placing source category and facility-wide HAP risks in the context of total HAP risks from all sources combined in the vicinity of each source, we are concerned about the uncertainties of doing so. Estimates of total HAP risk from emission sources other than those that we have studied in depth during this RTR review would have significantly greater associated uncertainties than the source category or

facility-wide estimates. Such aggregate or cumulative assessments would compound those uncertainties, making the assessments too unreliable.

B. How do we perform the technology review?

Our technology 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, we analyze their technical feasibility, estimated costs, energy implications, and non-air environmental impacts. We also consider the emission reductions associated with applying each development. This analysis informs our decision of whether it is “necessary” to revise the emissions standards. In addition, we consider the appropriateness of applying controls to new sources versus retrofitting existing sources. For this exercise, we consider any of the following to be a “development”:

• Any add-on control technology or other equipment that was not identified and considered during development of the original MACT standards;

• Any improvements in add-on control technology or other equipment (that were identified and considered during development of the original MACT standards) that could result in additional emissions reduction;

• Any work practice or operational procedure that was not identified or considered during development of the original MACT standards;

• Any process change or pollution prevention alternative that could be broadly applied to the industry and that was not identified or considered during development of the original MACT standards; and

• 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 NESHAPs (

i.e.,

the 2004 ALDT NESHAP; the 2004 MMPP NESHAP; and the 2004 PPP NESHAP), we review a variety of data sources in our investigation of potential practices, processes, or controls that may have not been 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 after the MACT standards being reviewed in this action (

e.g.,

NESHAP for Paint Stripping and Miscellaneous Surface Coating Operations at Area Sources (40 CFR part 63, subpart HHHHHH)). We also reviewed the results of other technology reviews for other surface coating source categories since the promulgation of the NESHAPs (

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 ALDT, the MMPP, and the PPP source categories, 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-specific market analyses and trade journals, to research advancements in add-on controls and lower HAP technology for coatings and solvents. For a more detailed discussion of our methods for performing these technology reviews, refer to the

Automobiles and Light-Duty Trucks Technology Review Memo, the Miscellaneous Metal Parts and Products Technology Review Memo

and the

Plastic Parts and Products Technology Review Memo,

available in the respective ALDT, MMPP, and PPP Dockets.

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

In this section, we provide a complete description of the types of analyses that we generally perform during the risk assessment process. In some cases, we do not perform a specific analysis because it is not relevant. For example, in the absence of emissions of HAP known to be persistent and bioaccumulative in the environment (PB-HAP), we would not perform a multipathway exposure assessment. Where we do not perform an analysis, we state that we do not and provide the reason. While we present all of our risk assessment methods, we only present risk assessment results for the analyses actually conducted (see the presentation of results in sections IV.A.1, IV.B.1, and IV.C.1 of this preamble).

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 ALDT, MMPP, and PPP Dockets contain the respective

Automobiles and Light-Duty Trucks Risk Assessment Report, Miscellaneous Metal Parts and Products Risk Assessment Report

and the

Plastic Parts and Products 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 the SAB review report issued in 2010. They are also consistent with the key recommendations contained in that report.

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,

June 2009. EPA-452/R-09-0006.

https://www3.epa.gov/airtoxics/rrisk/rtrpg.html.

1. How did we estimate actual emissions and identify the emissions release characteristics?

The actual emissions and the emission release characteristics for each facility were obtained primarily from either the 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 industry association or the specific 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 revised 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 estimates and emissions release characteristics, can be found in Appendix 1 to the

Automobiles and

Light-Duty Trucks Risk Assessment Report,

in the ALDT Docket; in Appendix 1 to the

Miscellaneous Metal Parts and Products Risk Assessment Report,

in the MMPP Docket; and Appendix 1 to the

Plastic Parts and Products Risk Assessment Report,

in the PPP 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 ALDT, MMPP, and PPP source categories, the EPA calculated allowable emissions by developing source category-specific multipliers of 1.1 for Automobiles and Light-duty Trucks and 1.2 for both Miscellaneous Metal Parts and Plastic Parts and Products. These multipliers were applied to the current emissions for each category to estimate the allowable emissions. The multipliers were based on information obtained from the facility operating permits and industry information.

For details on how the EPA estimated the MACT allowable emissions for the ALDT source category, please

see

Appendix 1 to the

Automobiles and Light-Duty Trucks Risk Assessment Report,

in the ALDT Docket (Docket ID No. EPA-HQ-OAR-2019-0314). For details on how the EPA calculated the MACT allowable emissions for the MMPP source category, please

see

Appendix 1 to the

Miscellaneous Metal Parts and Products Risk Assessment Report,

in the MMPP Docket (Docket ID No. EPA-HQ-OAR-2019-0312). For details on how the EPA calculated the MACT allowable emissions for the PPP source category, please

see

Appendix 1 to the

Plastic Parts and Products Risk Assessment Report,

in the PPP Docket (Docket ID No. EPA-HQ-OAR-2019-0313).

3. How do 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.

For more information about HEM-3, go to

https://www.epa.gov/fera/risk-assessment-and-modeling-human-exposure-model-hem.

a. Dispersion Modeling

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

To perform the dispersion modeling and to develop the preliminary risk estimates, HEM-3 draws on three data libraries. The first is a library of meteorological data, which is used for dispersion calculations. This library includes 1 year (2016) of hourly surface and upper air observations from 824 meteorological stations, selected to provide coverage of the U.S. and Puerto Rico. A second library of U.S. Census Bureau census block

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 are discussed below:

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).

A census block is the smallest geographic area for which census statistics are tabulated.

b. Risk From Chronic Exposure to HAP

In developing the risk assessment for chronic exposures, we use the estimated annual average ambient air concentrations of each HAP emitted by each source in the source categories. The HAP air concentrations at each nearby census block centroid located within 50 km of the facility are a surrogate for the chronic inhalation exposure concentration for all the people who reside in that census block. A distance of 50 km is consistent with both the analysis supporting the 1989 Benzene NESHAP (54 FR 38044, September 14, 1989) and the limitation of Gaussian dispersion modules, including AERMOD.

For each facility we calculate the MIR as the cancer risk associated with a continuous lifetime (24 hours per day, 7 days per week, 52 weeks per year, for a 70-year period) exposure to the maximum concentration at the centroid of each inhabited census block. We calculate individual cancer risk by multiplying the estimated lifetime exposure to the ambient concentration of each HAP (in micrograms per cubic meter (µg/m

)) 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 1 microgram of the pollutant per cubic meter of air. For residual risk assessments, we generally use UREs from the EPA's Integrated Risk Information System (IRIS). For carcinogenic pollutants without IRIS values, we look to other reputable sources of cancer dose-response values, often using California EPA (CalEPA) UREs, where available. In cases where new, scientifically credible dose-response values have been developed in a manner consistent with EPA guidelines and have undergone a peer review process similar to that used by the EPA, we may use such dose-response values in place of, or in addition to, other values, if appropriate. The pollutant-specific dose-response values used to estimate health risk are available at

https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants.

To estimate individual lifetime cancer risks associated with exposure to HAP emissions from each facility in the source category, we sum the risks for each of the carcinogenic HAP

emitted

by the modeled facility. We estimate cancer risk at every census block within 50 km of every facility in the source category. The MIR is the highest individual lifetime cancer risk estimated for any of those census blocks. In addition to calculating the MIR, we estimate the distribution of individual cancer risks for the source category by summing the number of individuals within 50 km of the sources whose estimated risk falls within a specified risk range. We also estimate annual cancer incidence by multiplying the estimated lifetime cancer risk at each census block by the number of people residing in that block, summing results for all of the census blocks, and then dividing this result by a 70-year lifetime.

The EPA's 2005

Guidelines for Carcinogen Risk Assessment

classifies carcinogens as: “carcinogenic to humans,” “likely to be carcinogenic to humans,” and “suggestive evidence of carcinogenic

potential.” These classifications also coincide with the terms “known carcinogen, probable carcinogen, and possible carcinogen,” respectively, which are the terms advocated in the EPA's

Guidelines for Carcinogen Risk Assessment,

published in 1986 (51 FR 33992, September 24, 1986). In August 2000, the document,

Supplemental Guidance for Conducting Health Risk Assessment of Chemical Mixtures

(EPA/630/R-00/002), was published as a supplement to the 1986 document. Copies of both documents can be obtained from

https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=20533&CFID=70315376&CFTOKEN=71597944.

Summing the risk of these individual compounds to obtain the cumulative cancer risk is an approach that was recommended by the EPA's SAB in their 2002 peer review of the EPA's National Air Toxics Assessment (NATA) titled

NATA—Evaluating the National-scale Air Toxics Assessment 1996 Data—an SAB Advisory,

available at

https://yosemite.epa.gov/sab/sabproduct.nsf/214C6E915BB04E14852570CA007A682C/$File/ecadv02001.pdf.

To assess the risk of noncancer health effects from chronic exposure to HAP, we calculate either an HQ or a target organ-specific hazard index (TOSHI). We calculate an HQ when a single noncancer HAP is emitted. Where more than one noncancer HAP is emitted, we sum the HQ for each of the HAP that affects a common target organ or target organ system to obtain a TOSHI. The HQ is the estimated exposure divided by the chronic noncancer dose-response value, which is a value selected from one of several sources. The preferred chronic noncancer dose-response value is the EPA RfC, defined as “an estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime” (

https://iaspub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&vocabName=IRIS%20Glossary

). In cases where an RfC from the EPA's IRIS is not available or where the EPA determines that using a value other than the RfC is appropriate, the chronic noncancer dose-response value can be a value from the following prioritized sources, which define their dose-response values similarly to the EPA: (1) The Agency for Toxic Substances and Disease Registry (ATSDR) Minimum Risk Level (

https://www.atsdr.cdc.gov/mrls/index.asp

); (2) the CalEPA Chronic Reference Exposure Level (REL) (

https://oehha.ca.gov/air/crnr/notice-adoption-air-toxics-hot-spots-program-guidance-manual-preparation-health-risk-0

); or (3) as noted above, a scientifically credible dose-response value that has been developed in a manner consistent with the EPA guidelines and has undergone a peer review process similar to that used by the EPA. The pollutant-specific dose-response values used to estimate health risks are available at

https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants.

c. Risk From Acute Exposure to HAP That May Cause Health Effects Other Than Cancer

For each HAP for which appropriate acute inhalation dose-response values are available, the EPA also assesses the potential health risks due to acute exposure. For these assessments, the EPA makes conservative assumptions about emission rates, meteorology, and exposure location. In this proposed rulemaking, as part of our efforts to continually improve our methodologies to evaluate the risks that HAP emitted from categories of industrial sources pose to human health and the environment,

we are revising our treatment of meteorological data to use reasonable worst-case air dispersion conditions in our acute risk screening assessments instead of worst-case air dispersion conditions. This revised treatment of meteorological data and the supporting rationale are described in more detail in

Automobiles and Light-Duty Trucks Risk Assessment Report, the Miscellaneous Metal Parts and Products Risk Assessment Report, and the Plastic Parts and Products Risk Assessment Report,

and in Appendix 5 of the report:

Technical Support Document for Acute Risk Screening Assessment.

We will be applying this revision in RTR rulemakings proposed on or after June 3, 2019.

See, e.g.,

U.S. EPA. “Screening Methodologies to Support Risk and Technology Reviews (RTR): A Case Study Analysis” (Draft Report, May 2017.

https://www3.epa.gov/ttn/atw/rrisk/rtrpg.html

To assess the potential acute risk to the maximally exposed individual, we use the peak hourly emission rate for each emission point,

reasonable worst-case air dispersion conditions (

i.e.,

99th percentile), and the point of highest off-site exposure. Specifically, we assume that peak emissions from the source category and reasonable worst-case air dispersion conditions co-occur and that a person is present at the point of maximum exposure.

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 to account for variability. This is documented in the

Automobiles and Light-Duty Trucks Risk Assessment Report, the Miscellaneous Metal Parts and Products Risk Assessment Report, and the Plastic Parts and Products Risk Assessment Report

and in Appendix 5 of the report:

Technical Support Document for Acute Risk Screening Assessment.

These documents are available in the ALDT Docket, the MMPP Docket, and the PPP 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 concentration by the acute dose-response value. For each HAP for which acute dose-response values are available, the EPA calculates acute HQs.

An acute REL is defined as “the concentration level at or below which no adverse health effects are anticipated for a specified exposure duration.”

Acute RELs are based on the most sensitive, relevant, adverse health effect reported in the peer-reviewed medical and toxicological literature. They are designed to protect the most sensitive individuals in the population through the inclusion of margins of safety. Because margins of safety are incorporated to address data gaps and uncertainties, exceeding the REL does not automatically indicate an adverse health impact. AEGLs represent threshold exposure limits for the general public and are applicable to emergency exposures ranging from 10 minutes to 8 hours.

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

(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.

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.

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.”

Id.

at 1. The ERPG-1 is defined as “the maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to 1 hour without experiencing other than mild transient adverse health effects or without perceiving a clearly defined, objectionable odor.”

Id.

at 2. Similarly, the ERPG-2 is defined as “the maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to one hour without experiencing or developing irreversible or other serious health effects or symptoms which could impair an individual's ability to take protective action.”

Id.

at 1.

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.

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.

The ALDT process is a continuous (non-batch) coating application and curing process which results in consistent emission rates. The sources in this category dip and spray-apply coatings onto the surface of the vehicle. The sources employ the use of various compliance options, which include the use of compliant coatings, averaging among coatings to meet the emission limits, and the use of add-on controls by facilities that cannot use the first two options. We expect that the hourly variations in emissions from these processes during routine operations to be minimal. Thus, applying the default multiplier of 10 to estimate the worst-case hourly emission rate is not reasonable for this category. We expect that minimal variations in emissions occur due to variations in the organic HAP content of the coatings. We calculated acute emissions by developing a source category-specific multiplier of 1.2 that was applied to the actual annual emissions, which were then divided by the total number of hours in a year (8,760 hours). A further discussion of why this factor was chosen can be found in Appendix 1 to the

Automobiles and Light-Duty Trucks Risk Assessment Report

in the ALDT Docket.

Similarly, for the MMPP source category, we expect to see minimal hour-to-hour variation in emissions during routine operations because coating operations dip or spray-apply coating onto the surface of metal parts and products in a continuous coating process. Thus, the default multiplier of 10 to estimate the worst-case hourly emission rate is not reasonable for this category. We expect that minimal variation in emissions occur due to variations in the organic HAP content of the coatings from batch to batch. We calculated acute emissions by developing a source category-specific multiplier of 1.2 that was applied to the actual annual emissions, which were then divided by the total number of hours in a year (8,760 hours). A further discussion of why this factor was chosen can be found in Appendix 1 to the

Miscellaneous Metal Parts and Products Risk Assessment Report

in the MMPP Docket.

For the PPP source category, we expect to see minimal hour-to-hour variation in emissions during routine operations because coating operations spray-apply coating onto the surface of plastic parts and products in a continuous coating process. Thus, the default multiplier of 10 to estimate the worst-case hourly emission rate is not reasonable for this category. We expect that minimal variation in emissions occur due to variations in the organic HAP content of the coatings from batch to batch. We calculated acute emissions by developing a source category-specific multiplier of 1.2 that was applied to the actual annual emissions, which were then divided by the total number of hours in a year (8,760 hours). A further discussion of why this factor was chosen can be found in Appendix 1 to the

Plastic Parts and Products Risk Assessment Report

in the PPP Docket.

In our acute inhalation screening risk assessment, acute impacts are deemed negligible for HAP where acute HQs are less than or equal to 1, and no further analysis is performed for these HAP. In cases where an acute HQ from the screening step is greater than 1, we assess the site-specific data to ensure that the acute HQ is at an off-site location. For the three source categories in this action, the acute data refinements consisted of plotting the HEM-3 polar grid results for each HAP with an acute HQ value greater than 1 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

Automobiles and Light-Duty Trucks, Miscellaneous Metal Parts and Products,

and

Plastic Parts and Products Risk Assessment Reports,

available in the respective ALDT, MMPP, and PPP Dockets.

4. How do we conduct the multipathway exposure and risk screening assessment?

The EPA conducts a tiered screening assessment examining the potential for significant human health risks due to exposures via routes other than inhalation (

i.e.,

ingestion). We first determine whether any sources in the source categories emitted any HAP known to be persistent and bioaccumulative in the invironment, as identified in the EPA's Air Toxics Risk Assessment Library (see Volume 1, Appendix D, at

https://www.epa.gov/sites/production/files/2013-08/documents/volume_1_reflibrary.pdf

For the ALDT source category, we identified emissions of lead. In evaluating the potential multipathway risk from emissions of lead compounds, rather than developing a screening threshold emission rate, we compare maximum estimated chronic inhalation exposure concentrations to the level of the current National Ambient Air Quality Standard (NAAQS) for lead (0.15 µg/m

Values below the level of the primary (health-based) lead NAAQS are considered to have a low potential for multipathway risk. For additional discussion of the multipathway screening results for this source category

see

section IV.A of this preamble and the

Automobiles and Light-Duty Trucks Risk Assessment Report

in the ALDT Docket.

In doing so, the EPA notes that the legal standard for a primary NAAQS—that a standard is requisite to protect public health and provide an adequate margin of safety (CAA section 109(b))—differs from the CAA section 112(f) standard (requiring, among other things, that the standard provide an “ample margin of safety to protect public health”). However, the primary lead NAAQS is a reasonable measure of determining risk acceptability (

i.e.,

the first step of the Benzene NESHAP analysis) since it is designed to protect the most susceptible group in the human population—children, including children living near major lead emitting sources. 73 FR 67002/3; 73 FR 67000/3; 73 FR 67005/1. In addition, applying the level of the primary lead NAAQS at the risk acceptability step is conservative, since that primary lead NAAQS reflects an adequate margin of safety.

For the MMPP source category, we identified emissions of arsenic, cadmium, and lead, so we proceeded to the next step of the evaluation. Except for lead, the human health risk screening assessment for PB-HAP consists of three progressive tiers. In a Tier 1 screening assessment, we determine whether the magnitude of the facility-specific emissions of PB-HAP warrants further evaluation to characterize human health risk through ingestion exposure. To facilitate this step, we use previously developed screening threshold emission rates for several PB-HAP that are based on a hypothetical upper-end screening exposure scenario developed for use in conjunction with the EPA's Total Risk Integrated Methodology.Fate, Transport, and Ecological Exposure (TRIM.FaTE) model. The PB-HAP with screening threshold emission rates are arsenic compounds, cadmium compounds, chlorinated dibenzodioxins and furans, mercury compounds, and polycyclic organic matter (POM). Based on the EPA estimates of toxicity and bioaccumulation potential, the pollutants above represent a conservative list for inclusion in multipathway risk assessments for RTR rules. (See Volume 1, Appendix D at

https://www.epa.gov/sites/production/files/2013-08/documents/volume_1_reflibrary.pdf.

) In this assessment, we compare the facility-specific emission rates of these PB-HAP to the screening threshold emission rates for each PB-HAP to assess the potential for significant human health risks via the ingestion pathway. We call this application of the TRIM.FaTE model the Tier 1 screening assessment. The ratio of a facility's actual emission rate to the Tier 1 screening threshold emission rate is a “screening value.”

We derive the Tier 1 screening threshold emission rates for these PB-HAP (other than lead compounds) to correspond to a maximum excess lifetime cancer risk of 1-in-1 million (

i.e.,

for arsenic compounds, polychlorinated dibenzodioxins and furans and POM) or, for HAP that cause noncancer health effects (

i.e.,

cadmium compounds and mercury compounds), a maximum HQ of 1. If the emission rate of any one PB-HAP or combination of carcinogenic PB-HAP in the Tier 1 screening assessment exceeds the Tier 1 screening threshold emission rate for any facility (

i.e.,

the screening value is greater than 1), we conduct a second screening assessment, which we call the Tier 2 screening assessment (ingestion rates are decoupled into separate upper-bound ingestion rates for the fisher, farmer, and gardener scenarios). Since, the PB-HAP emissions did not exceed the Tier 1 multipathway screening value of 1, the Tier 2 multipathway screen was not conducted.

In evaluating the potential multipathway risk from emissions of lead compounds, rather than developing a screening threshold emission rate, we compare maximum estimated chronic inhalation exposure concentrations to the level of the current National Ambient Air Quality Standard (NAAQS) for lead.

Values below the level of the primary (health-based) lead NAAQS are considered to have a low potential for multipathway risk.

i.e.,

For additional discussion of the multipathway screening results for this source category

see

section IV.B of this preamble and the

Miscellaneous Metal Parts and Products Risk Assessment Report

in the MMPP Docket.

For the PPP source category, we did not identify emissions of any PB-HAP. Therefore, further evaluation of multipathway risk was not conducted for the PPP source category.

5. How do 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 (POM), mercury (both inorganic mercury and methyl mercury), and lead compounds. The acid gases included in the screening assessment are hydrochloric acid (HCl) and hydrogen fluoride (HF).

HAP that persist and bioaccumulate are of particular environmental concern because they accumulate in the soil, sediment, and water. The acid gases, HCl and HF, 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

Automobiles and Light-Duty Trucks Risk Assessment Report,

the

Miscellaneous Metal Parts and Products Risk Assessment Report,

and the

Plastic Parts and Products Risk Assessment Report,

in the respective ALDT, MMPP and PPP Dockets.

b. Environmental Risk Screening Methodology

For the environmental risk screening assessment, the EPA first determined whether any facilities in the ALDT, MMPP, and PPP source categories emitted any of the environmental HAP. For the ALDT source category, we identified emissions of lead, HCl and HF. For the MMPP source category, we identified emissions of arsenic, cadmium, lead and HCl. For the PPP source category, we did not identify emissions of any environmental HAP.

Because the environmental HAP evaluated are emitted by at least one facility in the ALDT source category and the MMPP source category, we proceeded to the second step of the evaluation for each of these source categories.

c. PB-HAP Methodology

The environmental screening assessment includes six PB-HAP, arsenic compounds, cadmium compounds, dioxins/furans, POM, mercury (both inorganic mercury and methyl mercury), and lead compounds. With the exception of lead, the environmental risk screening assessment for PB-HAP consists of three tiers. The first tier of the environmental risk screening assessment uses the same health-protective conceptual model that is used for the Tier 1 human health screening assessment. TRIM.FaTE model simulations were used to back-calculate Tier 1 screening threshold emission rates. The screening threshold emission rates represent the emission rate in tons of pollutant per year that results in media concentrations at the facility that equal the relevant ecological benchmark. To assess emissions from each facility in the category, the reported emission rate for each PB-HAP was compared to the Tier 1 screening threshold emission rate for that PB-HAP for each assessment endpoint and effect level. If emissions from a facility do not exceed the Tier 1 screening threshold emission rate, the facility “passes” the screening assessment, and, therefore, is not evaluated further under the screening approach. If emissions from a facility exceed the Tier 1 screening threshold emission rate, we evaluate the facility further in Tier 2.

In Tier 2 of the environmental screening assessment, the screening threshold emission rates are adjusted to account for local meteorology and the actual location of lakes in the vicinity of facilities that did not pass the Tier 1 screening assessment. For soils, we evaluate the average soil concentration for all soil parcels within a 7.5-km radius for each facility and PB-HAP. For the water, sediment, and fish tissue concentrations, the highest value for each facility for each pollutant is used. If emission concentrations from a facility do not exceed the Tier 2 screening threshold emission rate, the facility “passes” the screening assessment and typically is not evaluated further. If emissions from a facility exceed the Tier 2 screening threshold emission rate, we evaluate the facility further in Tier 3.

In Tier 3 of the environmental screening assessment, we examine the suitability of the lakes around the facilities to support life and remove those that are not suitable (

e.g.,

lakes that have been filled in or are industrial ponds), adjust emissions for plume-rise, and conduct hour-by-hour time-series assessments. If these Tier 3 adjustments to the screening threshold emission rates still indicate the potential for an adverse environmental effect (

i.e.,

facility emission rate exceeds the screening threshold emission rate), we may elect to conduct a more refined assessment using more site-specific information. If, after additional refinement, the facility emission rate still exceeds the screening threshold emission rate, the facility may have the potential to cause an adverse environmental effect.

To evaluate the potential for an adverse environmental effect from lead, we compared the average modeled air concentrations (from HEM-3) of lead around each facility in the source category to the level of the secondary NAAQS for lead. The secondary lead NAAQS is a reasonable means of evaluating environmental risk because it is set to provide substantial protection against adverse welfare effects which can include “effects on soils, water, crops, vegetation, man-made materials, animals, wildlife, weather, visibility and climate, damage to and deterioration of property, and hazards to transportation, as well as effects on economic values and on personal comfort and well-being.”

d. Acid Gas Environmental Risk Methodology

The environmental screening assessment for acid gases evaluates the potential phytotoxicity and reduced productivity of plants due to chronic exposure to 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 units of acres and squared kilometers; the percentage of the modeled area around each facility that exceeds the ecological benchmark for each acid gas; and the area-weighted average screening value around each facility (calculated by dividing the area-weighted average concentration over the 50-km modeling domain by the ecological benchmark for each acid gas). For further information on the environmental screening assessment approach,

see

Appendix 9 of the

Automobiles and Light-Duty Trucks Risk Assessment Report,

the

Miscellaneous Metal Parts and Products Risk Assessment Report,

and the

Plastic Parts and Products Risk Assessment Report,

in the ALDT Docket, the MMPP Docket, and the PPP Docket, respectively.

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 each of these three source categories, 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

Automobiles and Light-Duty Trucks Risk Assessment Report, Miscellaneous Metal Parts and Products Risk Assessment Report,

and

Plastic Parts and Products Risk Assessment Report,

available in the respective dockets for this action, 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

Automobiles and Light-Duty Trucks Risk Assessment Report, Miscellaneous Metal Parts and Products Risk Assessment Report,

and

Plastic Parts and Products Risk Assessment Report,

available in the respective dockets for this action. If a multipathway site-specific assessment was performed for any of these source categories, 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 risk or the incidence, but the shape of the distribution of risks may be affected. With respect to outdoor exposures, actual exposures may not be as high if people spend time indoors, especially for very reactive pollutants or larger particles. For all factors, we reduce uncertainty when possible. For example, with respect to census-block centroids, we analyze large blocks using aerial imagery and adjust locations of the block centroids to better represent the population in the blocks. We also add additional receptor locations where the population of a block is not well represented by a single location.

d. Uncertainties in Dose-Response Relationships

There are uncertainties inherent in the development of the dose-response values used in our risk assessments for cancer effects from chronic exposures and noncancer effects from both chronic and acute exposures. Some

uncertainties are generally expressed quantitatively, and others are generally expressed in qualitative terms. We note, as a preface to this discussion, a point on dose-response uncertainty that is stated in the EPA's

2005 Guidelines for Carcinogen Risk Assessment;

namely, that “the primary goal of EPA actions is protection of human health; accordingly, as an Agency policy, risk assessment procedures, including default options that are used in the absence of scientific data to the contrary, should be health protective” (the EPA's

2005 Guidelines for Carcinogen Risk Assessment,

page 1-7). This is the approach followed here as summarized in the next paragraphs.

Cancer UREs used in our risk assessments are those that have been developed to generally provide an upper 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). In some circumstances, the true risk could be as low as zero; however, in other circumstances the risk could be greater.

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,

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.

IRIS glossary (

https://ofmpub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&glossaryName=IRIS%20Glossary

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.

See

A Review of the Reference Dose and Reference Concentration Processes,

U.S. EPA, December 2002, and

Methods for Derivation of Inhalation Reference Concentrations and Application of Inhalation Dosimetry,

U.S. EPA, 1994.

Many of the UFs used to account for variability and uncertainty in the development of acute dose-response values are quite similar to those developed for chronic durations. Additional adjustments are often applied to account for uncertainty in extrapolation from observations at one exposure duration (

e.g.,

4 hours) to derive an acute dose-response value at another exposure duration (

e.g.,

1 hour). Not all acute dose-response values are developed for the same purpose, and care must be taken when interpreting the results of an acute assessment of human health effects relative to the dose-response value or values being exceeded. Where relevant to the estimated exposures, the lack of acute dose-response values at different levels of severity should be factored into the risk characterization as potential uncertainties.

Uncertainty also exists in the selection of ecological benchmarks for the environmental risk screening assessment. We established a hierarchy of preferred benchmark sources to allow selection of benchmarks for each environmental HAP at each ecological assessment endpoint. We searched for benchmarks for three effect levels (

i.e.,

no-effects level, threshold-effect level, and probable effect level), but not all combinations of ecological assessment/environmental HAP had benchmarks for all three effect levels. Where multiple effect levels were available for a particular HAP and assessment endpoint, we used all of the available effect levels to help us determine whether risk exists and whether the risk could be considered significant and widespread.

Although we make every effort to identify appropriate human health effect dose-response values for all pollutants emitted by the sources in this risk assessment, some HAP emitted by these source categories 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 a person. In the acute screening assessment that we conduct under the RTR program, we assume that peak emissions from the source category and reasonable worst-case air dispersion conditions (

i.e.,

99th percentile) co-occur. We then include the additional assumption that a person is located at this point at the same time. Together, these assumptions represent a reasonable worst-case actual exposure scenario. In most cases, it is unlikely that a person would be located at the point of maximum exposure during the time when peak emissions and reasonable worst-case air dispersion conditions occur simultaneously.

f. Uncertainties in the Multipathway and Environmental Risk Screening Assessments

The ALDT source category emits PB-HAP (lead) and environmental HAP (lead, HF and HCl); therefore, further evaluation of multipathway risk and an environmental risk screening was conducted. The MMPP source category emits PB-HAP (arsenic, cadmium, and lead) and environmental HAP (arsenic, cadmium, lead, HF, and HCl); therefore, an environmental risk screening was conducted for this source category. The PPP source category in this action does not emit any PB-HAP or environmental HAP; therefore, further evaluation of multipathway risk and an environmental risk screening was not conducted for this source category.

For each source category, we generally rely on site-specific levels of PB-HAP or environmental HAP emissions to determine whether a refined assessment of the impacts from multipathway exposures is necessary or whether it is necessary to perform an environmental screening assessment.

This determination is based on the results of a three-tiered screening assessment that relies on the outputs from models—TRIM.FaTE and AERMOD—that estimate environmental pollutant concentrations and human exposures for five PB-HAP (dioxins, POM, mercury, cadmium, and arsenic) and two acid gases (HF and HCl). For lead, we use AERMOD to determine ambient air concentrations, which are then compared to the secondary NAAQS standard for lead. Two important types of uncertainty associated with the use of these models in RTR risk assessments and inherent to any assessment that relies on environmental modeling are model uncertainty and input uncertainty.

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.

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 the EPA SAB reviews and other reviews, we are confident that the models used in the screening assessments are appropriate and state-of-the-art for the multipathway and environmental screening risk assessments conducted in support of RTR.

Input uncertainty is concerned with how accurately the models have been configured and parameterized for the assessment at hand. For Tier 1 of the multipathway and environmental screening assessments, we configured the models to avoid underestimating exposure and risk. This was accomplished by selecting upper-end values from nationally representative datasets for the more influential parameters in the environmental model, including selection and spatial configuration of the area of interest, lake location and size, meteorology, surface water, soil characteristics, and structure of the aquatic food web. We also assume an ingestion exposure scenario and values for human exposure factors that represent reasonable maximum exposures.

For the environmental screening assessment for acid gases, we employ a single-tiered approach. We use the modeled air concentrations and compare those with ecological benchmarks.

For all tiers of the multipathway and environmental screening assessments, our approach to addressing model input uncertainty is generally cautious. We choose model inputs from the upper end of the range of possible values for the influential parameters used in the models, and we assume that the exposed individual exhibits ingestion behavior that would lead to a high total exposure. This approach reduces the likelihood of not identifying high risks for adverse impacts.

Despite the uncertainties, when individual pollutants or facilities do not exceed screening threshold emission rates (

i.e.,

screen out), we are confident that the potential for adverse multipathway impacts on human health is very low. On the other hand, when individual pollutants or facilities do exceed screening threshold emission rates, it does not mean that impacts are significant, only that we cannot rule out that possibility and that a refined assessment for the site might be necessary to obtain a more accurate risk characterization for the source category.

The EPA evaluates the following HAP in the multipathway and/or environmental risk screening assessments, where applicable: Arsenic, cadmium, dioxins/furans, lead, mercury (both inorganic and methyl mercury), POM, HCl, and HF. These HAP represent pollutants that can cause adverse impacts either through direct exposure to HAP in the air or through exposure to HAP that are deposited from the air onto soils and surface waters and then through the environment into the food web. These HAP represent those HAP for which we can conduct a meaningful multipathway or environmental screening risk assessment. For other HAP not included in our screening assessments, the model has not been parameterized such that it can be used for that purpose. In some cases, depending on the HAP, we may not have appropriate multipathway models that allow us to predict the concentration of that pollutant. The EPA acknowledges that other HAP beyond these that we are evaluating may have the potential to cause adverse effects and, therefore, the EPA may evaluate other relevant HAP in the future, as modeling science and resources allow.

IV. Analytical Results and Proposed Decisions

A. What are the analytical results and proposed decisions for the surface coating of automobiles and light-duty trucks source category?

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

As described in section III of this preamble, for the ALDT source category, we conducted a risk assessment for all HAP emitted. We present results of the risk assessment briefly below and in more detail in the

Automobiles and Light-Duty Trucks Risk Assessment Report

in the ALDT Docket (Docket ID No. EPA-HQ-OAR-2019-0314).

a. Chronic Inhalation Risk Assessment Results

Table 2 of this preamble provides a summary of the results of the inhalation risk assessment for the source category.

Table 2—Surface Coating of Automobiles and Light-Duty Trucks Source Category Inhalation Risk Assessment Results

Risk assessment

Maximum individual

cancer risk

(in 1 million)

Based on actual emissions

Based on

allowable

emissions

Estimated population at increased risk of cancer ≥1-in-1 million

Based on

actual

emissions

Based on

allowable

emissions

Estimated annual cancer incidence

(cases per year)

Based on

actual

emissions

Based on

allowable

emissions

Maximum chronic

noncancer

TOSHI

Based on

actual

emissions

Based on

allowable

emissions

Maximum screening acute noncancer HQ

Based on

actual

emissions

Source Category

15,000

19,000

0.01

0.3

HQREL = 1.

Whole Facility

48,000

0.02

0.3

The target organ specific hazard index (TOSHI) is the sum of the chronic noncancer HQs for substances that affect the same target organ or organ system.

The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop HQ values.

The results of the inhalation risk modeling using actual emissions data, as shown in Table 2 of this preamble, indicate that the maximum individual cancer risk based on actual emissions (lifetime) could be up to 10-in-1 million (driven by naphthalene and ethyl benzene from miscellaneous industrial processes—other/not classified), the maximum chronic noncancer TOSHI value based on actual emissions could be up to 0.3 (driven by hexamethylene-1,6-diisocyanate from a painting topcoat process), and the maximum screening acute noncancer HQ value (off-facility site) could be up to 1 (driven by formaldehyde). The total estimated annual cancer incidence (national) from these facilities based on actual emission levels is 0.01 excess cancer cases per year or 1 case in every 100 years.

b. Screening Level Acute Risk Assessment Results

Table 2 of this preamble shows the acute risk results for the ALDT source category. The screening analysis for acute impacts was based on an industry specific multiplier of 1.2, to estimate the peak emission rates from the average rates. For more detailed acute risk results, refer to the

Automobiles and Light-Duty Trucks Risk Assessment Report,

in the ALDT Docket.

c. Multipathway Risk Screening Results

The emissions data for the ALDT source category indicate that one PB-HAP is emitted by sources within this source category: Lead. In evaluating the potential for multipathway effects from emissions of lead, we compared modeled annual lead concentrations to the NAAQS for lead (0.15 µg/m3, arithmetic mean concentration over a 3-month period). The highest annual average lead concentration of 1.5 × 10

−5

µg/m

is below the NAAQS for lead, indicating a low potential for multipathway impacts of concern due to lead even assuming a shorter averaging period is. Therefore, we do not expect any human health multipathway risks as a result of emissions from this source category.

d. Environmental Risk Screening Results

The emissions data for the ALDT source category indicate that three environmental HAP are emitted by sources within this source category: Lead, HCl and HF. Therefore, we conducted a screening-level evaluation of the potential adverse environmental effects associated with emissions of lead, HCl, and HF for the ALDT source category. In evaluating the potential for adverse environmental effects from emissions of lead, we compared modeled annual lead concentrations to the secondary NAAQS for lead (0.15 µg/m

, arithmetic mean concentration over a 3-month period). The highest annual average lead concentration of 1.5 × 10

−5

µg/m

is below the secondary NAAQS for lead, indicating a low potential for adverse environmental impacts due to lead even assuming a shorter averaging period is analyzed. For both HCl and HF, each individual concentration (

i.e.,

each off-site data point in the modeling domain) was below the ecological benchmarks for all facilities. Therefore, we do not expect an adverse environmental effect as a result of HAP emissions from this source category.

e. Facility-Wide Risk Results

Fifteen facilities have a facility-wide cancer MIR greater than or equal to 1-in-1 million. The maximum facility-wide cancer MIR is 10-in-1 million, driven by naphthalene and ethyl benzene from miscellaneous industrial processes—other/not classified. The total estimated cancer incidence from the whole facility is 0.02 excess cancer cases per year, or one excess case in every 50 years. Approximately 48,000 people were estimated to have cancer risks above 1-in-1 million from exposure to HAP emitted from both MACT and non-MACT sources at 15 of the 43 facilities in this source category. The maximum facility-wide TOSHI for the source category is estimated to be 0.3, mainly driven by emissions of hexamethylene-1,6-diisocyanate from a painting topcoat process.

f. What demographic groups might benefit from this regulation?

To examine the potential for any environmental justice issues that might be associated with the source category, we performed a demographic analysis, which is an assessment of risks to individual demographic groups of the populations living within 5 km and within 50 km of the facilities. In the analysis, we evaluated the distribution of HAP-related cancer and noncancer risks from the ALDT source category across different demographic groups within the populations living near facilities.

The results of the demographic analysis are summarized in Table 3 of this preamble. These results, for various demographic groups, are based on the estimated risks from actual emissions levels for the population living within 50 km of the facilities.

Table 3—Surface Coating of Automobiles and Light-Duty Trucks Source Category Demographic Risk Analysis Results

Nationwide

Population with

cancer risk at or

above 1-in-1

million due to

surface coating

of automobiles

and light-duty

trucks

Population with

chronic noncancer

HI above 1 due to

surface coating

of automobiles

and light-duty

trucks

Total Population

317,746,049

15,000

White and Minority by Percent

White

Minority

Minority Detail by Percent

African American

Native American

0.8

0.2

Hispanic or Latino

Other and Multiracial

Income by Percent

Below the Poverty Level

Above the Poverty Level

Education by Percent

Over 25 Without High a School Diploma

Over 25 With a High School Diploma

Linguistically Isolated by Percent

Linguistically Isolated

The results of the ALDT source category demographic analysis indicate that emissions from the source category expose approximately 15,000 people to a cancer risk at or above 1-in-1 million and no one to a chronic noncancer HI greater than 1. The percent of minorities is similar nationally (38 percent) and for the category population with cancer risk greater than or equal to 1-in-1 million (40 percent). However, the category population with cancer risk greater than or equal to 1-in-1 million has a greater percentage of Hispanic (27 percent) as compared to nationally (18 percent).

The methodology and the results of the demographic analysis are presented in a technical report titled

Risk and Technology Review—Analysis of Demographic Factors for Populations Living Near Automobile and Light-Duty Truck Surface Coating Source Category Operations,

March 2019 (hereafter referred to as the

Automobiles and Light-Duty Trucks Demographic Analysis Report

) in the ALDT Docket.

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

a. Risk Acceptability

As noted in section III.A of this preamble, we weigh all health risk factors in our risk acceptability determination, including the cancer MIR, the number of persons in various cancer and noncancer risk ranges, cancer incidence, the maximum noncancer TOSHI, the maximum acute noncancer HQ, the extent of noncancer risks, the distribution of cancer and noncancer risks in the exposed population, and risk estimation uncertainties (54 FR 38044, September 14, 1989).

For the ALDT source category, the risk analysis indicates that the cancer risks to the individual most exposed could be up to 10-in-1 million due to actual emissions or based on allowable emissions. These risks are considerably less than 100-in-1 million, which is the presumptive upper limit of acceptable risk. The risk analysis also shows very low cancer incidence (0.01 cases per year for actual and allowable emissions), and we did not identify a potential for adverse chronic noncancer health effects. The acute noncancer risks are low at an HQ of 1 (based on the REL) for formaldehyde. Therefore, we find there is little potential concern of acute noncancer health impacts from actual emissions. In addition, the risk assessment indicates no significant potential for multipathway health effects.

Considering all of the health risk information and factors discussed above, including the uncertainties discussed in section III.C.7 of this preamble, we propose to find that the risks from the ALDT source category are acceptable.

b. Ample Margin of Safety Analysis

Although we are proposing that the risks from the ALDT source category are acceptable, risk estimates for approximately 15,000 individuals in the exposed population are above 1-in-1 million at the actual emissions level and 19,000 individuals at the allowable emissions level. Consequently, we further considered whether the MACT standards for the ALDT source category provide an ample margin of safety to protect public health. In this ample margin of safety analysis, we investigated available emissions control options that might reduce the risk from the source category. We considered this information along with all of the health risks and other health information considered in our determination of risk acceptability.

c. Environmental Effects

The emissions data for the ALDT source category indicate that three environmental HAP are emitted by sources within this source category: Lead, HCl, and HF. The screening-level evaluation of the potential for adverse environmental effects from emissions of lead indicated that the secondary

NAAQS for lead would not be exceeded by any facility. The screening-level evaluation of the potential for adverse environmental effects associated with emissions of HCl and HF from the ALDT source category indicated that each individual concentration (

i.e.,

each off-site data point in the modeling domain) was below the ecological benchmarks for all facilities. In addition, we are unaware of any adverse environmental effects caused by HAP emitted by this source category. Therefore, we do not expect there to be an adverse environmental effect as a result of HAP emissions from this source category and we are proposing that it is not necessary to set a more stringent standard to prevent, taking into consideration costs, energy, safety, and other relevant factors, an adverse environmental effect.

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

As described in section III.B of this preamble, our technology review focused on identifying developments in practices, processes, and control technologies for the ALDT source category. The EPA reviewed various information sources regarding emission sources that are currently regulated by the ALDT NESHAP to support the technology review. The information sources included the following: The RBLC; state regulations; facility operating permits; regulatory actions, including technology reviews, promulgated for other surface coating NESHAP subsequent to the ALDT NESHAP; site visits; discussions with individual ALDT surface coating facilities; and industry information. The primary emission sources for the technology review included the following: The coating operations; all storage containers and mixing vessels in which coatings, thinners, and cleaning materials are stored or mixed; all manual and automated equipment and containers used for conveying coatings, thinners, and cleaning materials; and all storage containers and all manual and automated equipment and containers used for conveying waste materials generated by a coating operation.

Based on our review, we did not identify any add-on control technologies, process equipment, work practices or procedures that were not previously considered during development of the 2004 ALDT NESHAP, and we did not identify any new or improved add-on control technologies that would result in additional emission reductions. A brief summary of the EPA's findings in conducting the technology review of ALDT surface coating operations follows. For a detailed discussion of the EPA's findings, refer to the memorandum,

Technology Review for Surface Coating Operations in the Automobiles and Light-Duty Trucks Source Category,

in the ALDT Docket.

During 2004 MACT development for the ALDT NESHAP, numerical emission limits were determined for new and existing major sources within the four combinations of coating operations, for a total of eight HAP emissions limits. The emission limits were based on industry survey responses and the industry's use of low- or no-HAP coatings and thinners, high efficiency coatings spray equipment (including robotic spraying), and add-on capture and control technologies. Alternately, the NESHAP provides sources with the option of limiting HAP emissions with capture and add-on control to achieve an overall control efficiency of 95-percent. During development of that rulemaking, we identified the beyond-the-floor option to require the use of capture systems and add-on control devices for all ALDT surface coating operations. This option was rejected because we determined the additional emission reductions achieved using the beyond-the-floor option did not warrant the costs each affected source would incur or the incremental cost per ton of HAP reduced (67 FR 78622, December 24, 2002).

For this technology review, we used the EPA's NEI and the ECHO databases to identify facilities that are currently subject to the ALDT NESHAP. We also consulted Regional and state regulations and operating permits. California has existing surface coating rules for VOC from vehicle assembly plants within two air quality management districts (AQMD): Bay Area AQMD and South Coast AQMD. No state VOC rules for ALDT surface coating operations were identified that had VOC limits that would translate into lower HAP content limits. The VOC content limits in state rules (

e.g.,

BAAQMD Rule 8-13 and SCAQMD Rule 1115) are an order of magnitude higher than the HAP content limits in the ALDT NESHAP. Because the HAP are only a small fraction of the VOC in these coatings, complying with these state VOC standards would not limit HAP emissions to levels that are more stringent than the levels required.

Our search of the RBLC database for improvements in ALDT coating technologies provided results for 22 facilities with permit dates of 2000 or later. Facilities reported the use of VOC and HAP content limits, electrodeposition primers, regenerative thermal oxidizers (RTOs), catalytic oxidation, and thermal oxidation. All of these control technologies were in use by the ALDT surface coating industry during development of the ALDT NESHAP and already were considered in the development of the ALDT NESHAP. Therefore, we concluded that the results of the search did not result in any improvements in add-on control technology or other equipment.

We reviewed other surface coating NESHAP promulgated after the ALDT NESHAP to determine whether any requirements exceed the ALDT MACT level of control or included technologies that were not considered during the development of the original ALDT NESHAP. These NESHAP include Paint Stripping and Miscellaneous Surface Coating Operations at Area Sources (40 CFR part 63, subpart HHHHHH), and Nine Metal Fabrication and Finishing Area Source Categories (40 CFR part 63, subpart XXXXXX). We also reviewed the results of the technology reviews for the following NESHAP: Printing and Publishing (40 CFR part 63, subpart KK), Shipbuilding and Ship Repair (40 CFR part 63, subpart II), Wood Furniture Manufacturing (40 CFR part 63, subpart JJ), and Aerospace Manufacturing and Rework Facilities (40 CFR part 63, subpart GG).

Technology reviews for these NESHAP identified permanent total enclosures (PTE) and/or RTOs as improvements in add-on control technology. The original ALDT NESHAP includes a compliance option involving the use of a PTE and an add-on control device. Because these measures were considered in the development of the original ALDT NESHAP and reflected in the MACT level of control, we concluded that these measures do not represent an improvement in control technology under CAA section 112(d)(6).

The control technology assessment conducted for the Paint Stripping and Miscellaneous Surface Coating NESHAP and Nine Metal Fabrication and Finishing NESHAP confined all coating operations to a spray booth fitted with high-efficiency filters, use of high-transfer efficiency spray guns, and training and certification of spray equipment operator to optimize transfer efficiency for facilities that spray apply coatings containing certain inorganic HAP. The technology controls for inorganic HAP adopted in subparts HHHHHH and XXXXXX, spray booths fitted with overspray filters and the use of high efficiency spray equipment, were already considered in the development of the original ALDT NESHAP, and, therefore, do not

constitute a development for the purpose of the technology review.

The technology review conducted for the Wood Furniture NESHAP identified the use of more efficient spray guns as a technology review development and revised the requirements to prohibit the use of conventional spray guns. Air-assisted airless spraying was added as a more efficient coating application technology. The original ALDT NESHAP is based on the use of high-efficiency application technology, such as airless and electrostatic spray equipment. This equipment increases coating transfer efficiency, minimizes emissions by reducing the amount of coating sprayed and still achieves a given film thickness with exceptional finish. The format of the ALDT emission limits, in mass of HAP per mass of coating solids applied to the part, accounts for the transfer efficiency of the application equipment and is based on high-efficiency methods.

The technology review conducted for the Printing and Publishing NESHAP identified the use of a PTE in the form of coating spray booths and curing tunnels. These PTEs are commonly used in ALDT surface coating operations to maintain a clean environment for applying the coatings, and for capturing and removing coating overspray and solvent vapors from the coating area. Therefore, the use of a PTE, as identified in the Printing and Publishing NESHAP technology review, does not represent a development in control technology with respect to ALDT surface coating operations.

In conclusion, we found no improvements in add-on control technology or other equipment during review of the RBLC, the state rules, and subsequent NESHAP that were not already identified and considered during the ALDT NESHAP development.

Alternatives to conventional solvent-borne coatings were identified and considered during MACT development but were not considered to be suitable for all ALDT coating applications. These alternative coatings include higher solids coatings, waterborne coatings, low-energy electron beam ultraviolet (UV) cured coatings, and powder coating. Waterborne and higher solids coatings with lower HAP and VOC content were considered in the development of the proposed and final standards and are already reflected in the HAP emission limitations in the final rule. Industry trends and advances in coating formulation, as documented in the

ACA Industry Market Analysis,

showed that powder coated finishes would be difficult to repair and would likely require refinishing the entire car in case of damage. Further, the

ACA analysis

stated that no progress had been made in overcoming technical hurdles that would make UV-cured coatings applicable to main vehicle body parts (

e.g.,

shadowing of certain areas from UV rays, high energy demands, residual UV photo-initiators in the coating film). Therefore, the EPA did not identify any developments in coating technology, other process changes, or pollution prevention alternatives that would represent a development relative to the coating technologies on which the final rule is based.

Finally, no improvements in work practices or operational procedures were identified for the ALDT source category that were not previously identified and considered during MACT development. The current MACT standards require that, if a facility uses add-on controls to comply with the emission limitations, 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, those coating operations. If a facility is not using add-on controls and is using either the compliant material option or the emission rate without add-on controls option, the facility does not need to comply with work practice standards. Under the emission rate option, HAP emitted from spills or from containers would be counted against the facility in the compliance calculations, so facilities must already minimize these losses to maintain compliance.

Based on these findings, we conclude that there have not been any developments in add-on control technology or other equipment not identified and considered during MACT development, nor any improvements in add-on controls, nor any significant changes in the cost (including cost effectiveness) of the add-on controls. Therefore, we are proposing no revisions to the ALDT NESHAP pursuant to CAA section 112(d)(6). For further discussion of the technology review results, refer to the

Automobiles and Light-Duty Trucks Technology Review Memo,

in the ALDT Docket.

4. What other actions are we proposing for the ALDT source category?

We are proposing to require electronic subm

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