# National Emission Standards for Hazardous Air Pollutants: Surface Coating of Automobiles and Light-Duty Trucks

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URL: https://www.frixlaw.com/law-library/documents/fr%3A02-31420

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** December 24, 2002
- **Citation:** 67 FR 78612

## Text

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 63, 264, and 265
[FRL-7418-4]
RIN 2060-AG99
National Emission Standards for Hazardous Air Pollutants: Surface Coating of Automobiles and Light-Duty Trucks

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule; amendments.

SUMMARY:

This action proposes national emission standards for hazardous air pollutants (NESHAP) for automobile and light-duty truck surface coating operations located at major sources of hazardous air pollutants (HAP). The proposed NESHAP would implement section 112(d) of the Clean Air Act (CAA) by requiring these operations to meet HAP emission standards reflecting the application of the maximum achievable control technology (MACT). The primary HAP emitted by these operations are toluene, xylene, glycol ethers, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), ethylbenzene, and methanol. The proposed rule would reduce nationwide HAP emissions from these major sources by about 60 percent.

This action also proposes to amend the Air Emission Standards for Equipment Leaks for owners and operators of hazardous waste treatment, storage, and disposal facilities to exempt certain activities covered by the proposed NESHAP from these standards.

DATES:

Comments.
Submit comments on or before February 7, 2003.

Public Hearing.
If anyone contacts EPA requesting to speak at a public hearing, they should do so by January 3, 2003. If requested, a public hearing will be held approximately 15 days after the date of publication of this document in the
Federal Register
.

ADDRESSES:

Comments.
By U.S. Postal Service, written comments should be submitted (in duplicate if possible) to: Office of Air and Radiation Docket and Information Center (6102T), Attention Docket Number A-2001-22, U.S. EPA, 1200 Pennsylvania Avenue, NW, Washington, DC 20460. In person or by courier, deliver comments (in duplicate if possible) to: Office of Air and Radiation Docket and Information Center (6102T), Attention Docket Number A-2001-22, U.S. EPA, 1301 Constitution Avenue, NW., Room B102, Washington, DC 20460. The EPA requests a separate copy also be sent to the contact person listed in
FOR FURTHER INFORMATION CONTACT
.

Public Hearing.
If a public hearing is held, it will be held at our Office of Administration auditorium in Research Triangle Park, North Carolina. You should contact Ms. Janet Eck, Coatings and Consumer Products Group, Emission Standards Division (C539-03), U.S. EPA, Research Triangle Park, North Carolina 27711, telephone number (919) 541-7946 to request to speak at a public hearing or to find out if a hearing will be held.

Docket.
Docket No. A-2001-22 contains supporting information used in developing the proposed standards. The docket is located at the U.S. EPA, 1301 Constitution Avenue, NW, Washington, DC 20460 in Room B108, and may be inspected from 8:30 a.m. to 5:30 p.m., Monday through Friday, excluding legal holidays.

FOR FURTHER INFORMATION CONTACT:

Mr. David Salman, Coatings and Consumer Products Group, Emission Standards Division (C539-03), U.S. EPA, Research Triangle Park, NC 27711; telephone number (919) 541-0859; facsimile number (919) 541-5689; electronic mail (e-mail) address:
salman.dave@epa.gov.

SUPPLEMENTARY INFORMATION:

Comments.
Comments and data may be submitted by e-mail to: a-and-r-docket@epa.gov. Electronic comments must be submitted as an ASCII file to avoid the use of special characters and encryption problems and will also be accepted on disks in WordPerfect® file format. All comments and data submitted in electronic form must note the docket number: A-2001-22. No confidential business information (CBI) should be submitted by e-mail. Electronic comments may be filed online at many Federal Depository Libraries.

Commenters wishing to submit proprietary information for consideration must clearly distinguish such information from other comments and clearly label it as CBI. Send submissions containing such proprietary information directly to the following address, and not to the public docket, to ensure that proprietary information is not inadvertently placed in the docket: Mr. David Salman, c/o OAQPS Document Control Officer (C404-02), U.S. EPA, Research Triangle Park, NC 27711. The EPA will disclose information identified as CBI only to the extent allowed by the procedures set forth in 40 CFR part 2. If no claim of confidentiality accompanies a submission when it is received by the EPA, the information may be made available to the public without further notice to the commenter.

Public Hearing.
Persons interested in presenting oral testimony or inquiring as to whether a hearing is to be held should contact Ms. Janet Eck, Coatings and Consumer Products Group, Emission Standards Division (C539-03), U.S. EPA, Research Triangle Park, North Carolina 27711; telephone number (919) 541-7946. Persons interested in attending the public hearing should also contact Ms. Eck to verify the time, date, and location of the hearing. The public hearing will provide interested parties the opportunity to present data, views, or arguments concerning these proposed emission standards.

Docket.
The docket is an organized and complete file of all the information considered by the EPA in the development of this rulemaking. The docket is a dynamic file because material is added throughout the rulemaking process. The docketing system is intended to allow members of the public and industries involved to readily identify and locate documents so that they can effectively participate in the rulemaking process. Along with the proposed and promulgated standards and their preambles, the contents of the docket will serve as the record in the case of judicial review. (See section 307(d)(7)(A) of the CAA.) The regulatory text and other materials related to this rulemaking are available for review in the docket or copies may be mailed on request from the Air and Radiation Docket and Information Center by calling (202) 566-1742. A reasonable fee may be charged for copying docket materials.

Worldwide Web (WWW).
In addition to being available in the docket, an electronic copy of this proposed rule will also be available on the WWW through the Technology Transfer Network (TTN). Following signature by the EPA Administrator, a copy of the proposed rule will be posted on the TTN's policy and guidance page for newly proposed or promulgated rules at
http://www.epa.gov/ttn/oarpg.
The TTN provides information and technology exchange in various areas of air pollution control. If more information regarding the TTN is needed, call the TTN HELP line at (919) 541-5384.

Regulated Entities.
Categories and entities potentially regulated by this action are listed in Table 1.

Table 1.—Categories and Entities Potentially Regulated by the Proposed Standards

Category
NAICS
Examples of potentially regulated entities

Industry

336111
336112
336211

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

This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this action. To determine whether your coating operation is regulated by this action, you should examine the applicability criteria in section § 63.3081 of the proposed rule. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed in the preceding
FOR FURTHER INFORMATION CONTACT
section.

Outline.
The information presented in this preamble is organized as follows:

I. Background

A. What is the source of authority for development of NESHAP?

B. What criteria are used in the development of NESHAP?

C. What are the health effects associated with HAP emissions from automobile and light-duty truck surface coating?

II. Summary of the Proposed Rule

A. What source categories are affected by this proposed rule?

B. What is the relationship to other rules?

C. What are the primary sources of emissions and what are the emissions?

D. What is the affected source?

E. What are the emission limits, operating limits, and other standards?

F. What are the testing and initial compliance requirements?

G. What are the continuous compliance provisions?

H. What are the notification, recordkeeping, and reporting requirements?

III. Rationale for Selecting the Proposed Standards

A. How did we select the source category?

B. How did we select the regulated pollutants?

C. How did we select the affected source?

D. How did we determine the basis and level of the proposed standards for existing and new sources?

E. How did we select the format of the proposed standards?

F. How did we select the testing and initial compliance requirements?

G. How did we select the continuous compliance requirements?

H. How did we select the notification, recordkeeping, and reporting requirements?

I. How did we select the compliance date?

IV. Summary of Environmental, Energy, and Economic Impacts

A. What are the air quality impacts?

B. What are the cost impacts?

C. What are the economic impacts?

D. What are the non-air health, environmental, and energy impacts?

E. Can we achieve the goals of the proposed rule in a less costly manner?

V. How will the proposed amendments to 40 CFR parts 264 and 265, subparts BB of the hazardous waste regulations be implemented in the States?

A. Applicability of Federal Rules in Authorized States

B. Authorization of States for Today's Proposed Amendments

VI. Solicitation of Comments and Public Participation

VII. Administrative Requirements

A. Executive Order 12866, Regulatory Planning and Review

B. Executive Order 13132, Federalism

C. Executive Order 13175, Consultation and Coordination with Indian Tribal Governments

D. Executive Order 13045, Protection of Children from Environmental Health Risks and Safety Risks

E. Executive Order 13211, Actions Concerning Regulations that Significantly Affect Energy Supply, Distribution, or Use

F. Unfunded Mandates Reform Act of 1995

G. Regulatory Flexibility Act (RFA), as Amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA), 5 U.S.C. 601,
et seq.

H. Paperwork Reduction Act

I. National Technology Transfer and Advancement Act

I. Background

A. What is the Source of Authority For Development of NESHAP?

Section 112 of the CAA requires us to list categories and subcategories of major sources and area sources of HAP and to establish NESHAP for the listed source categories and subcategories. The Surface Coating of Automobiles and Light-duty Trucks category of major sources was listed on July 16, 1992 (57 FR 31576). Major sources of HAP are those that emit or have the potential to emit equal to, or greater than, 9.1 megagrams per year (Mg/yr) (10 tons per year (tpy)) of any one HAP or 22.7 Mg/yr (25 tpy) of any combination of HAP.

B. What Criteria Are Used in the Development of NESHAP?

Section 112 of the CAA requires that we establish NESHAP for the control of HAP from both new and existing major sources. The CAA requires the NESHAP to reflect the maximum degree of reduction in emissions of HAP that is achievable. This level of control is commonly referred to as the MACT.

The MACT floor is the minimum control level allowed for NESHAP and is defined under section 112(d)(3) of the CAA. In essence, the MACT floor ensures that the standard is set at a level that assures that all major sources achieve the level of control at least as stringent as that already achieved by the better-controlled and lower-emitting sources in each source category or subcategory. For new sources, the MACT floor cannot be less stringent than the emission control that is achieved in practice by the best-controlled similar source. The MACT standards for existing sources can be less stringent than standards for new sources, but they cannot be less stringent than the average emission limitation achieved by the best-performing 12 percent of existing sources in the category or subcategory (or the best-performing five sources for categories or subcategories with fewer than 30 sources).

In developing MACT, we also consider control options that are more stringent than the floor. We may establish standards more stringent than the floor based on the consideration of cost of achieving the emissions reductions, any non-air quality health and environmental impacts, and energy requirements.

C. What Are the Health Effects Associated With HAP Emissions From Automobile and Light-Duty Truck Surface Coating?

The major HAP emitted from the automobile and light-duty truck surface coating source category are toluene, xylene, glycol ethers, MEK, MIBK, ethylbenzene, and methanol. These compounds account for over 95 percent of the nationwide HAP emissions from this source category. These pollutants can cause toxic effects following sufficient exposure. Some of the potential toxic effects include effects to the central nervous system, such as fatigue, nausea, tremors, and lack of coordination; adverse effects on the liver, kidneys, and blood; respiratory effects; and developmental effects.

The degree of adverse effects to human health from exposure to HAP can range from mild to severe. The extent and degree to which the human health effects may be experienced are

dependent upon (1) the ambient concentration observed in the area (as influenced by emission rates, meteorological conditions, and terrain); (2) the frequency and duration of exposures; (3) characteristics of exposed individuals (genetics, age, preexisting health conditions, and lifestyle), which vary significantly with the population; and (4) pollutant-specific characteristics (toxicity, half-life in the environment, bioaccumulation, and persistence).

II. Summary of the Proposed Rule

A. What Source Categories Are Affected by This Proposed Rule?

The proposed rule would apply to you if you own or operate an automobile and light-duty truck surface coating operation that is a major source, or is located at a major source, or is part of a major source of HAP emissions. We have defined an automobile and light-duty truck surface coating operation as any facility engaged in the surface coating of new automobile or new light-duty truck bodies or collections of body parts for new automobiles or new light-duty trucks. Coating operations included in this source category include, but are not limited to, the application of electrodeposition primer, primer-surfacer, topcoat (including basecoat and clear coat), final repair, glass bonding primer, glass bonding adhesive, sealer, adhesive, and deadener. The application of blackout and anti-chip materials is included in these coating operations, as is the cleaning and purging of equipment associated with the coating operations. Automobile customizers, body shops, and refinishers are excluded from this source category. Coating of separate, non-body miscellaneous metal parts and separate, non-body plastic parts that are not attached to the vehicle body at the time that the coatings are applied to these parts is excluded from this source category.

You would not be subject to the proposed rule if your coating operation is located at an area source. An area source is any stationary source of HAP that is not a major source. You may establish area source status prior to the compliance date of the final rule by limiting the source's potential to emit HAP through appropriate mechanisms available through the permitting authority.

The source category does not include research or laboratory facilities or janitorial, building, and facility maintenance operations.

We are also proposing to amend the Resource Conservation and Recovery Act (RCRA) Air Emissions Standards for Equipment Leaks at 40 CFR parts 264 and 265, subparts BB. The amendments would exempt facilities which would otherwise be subject to requirements of subparts BB if they are subject to the requirements of this proposed NESHAP. Generally, subparts BB of 40 CFR parts 264 and 265 apply to equipment that contains or contacts RCRA hazardous wastes with organic concentrations of at least 10 percent by weight. The regulations apply to large quantity generators as well as to RCRA treatment, storage, and disposal facilities. The regulations were designed to minimize the potential for leaks from pumps, valves, flanges, and connections.

The work practice standards that must be met in this proposed NESHAP in § 63.3094 address coating line purging emissions that would result from solvent purging of coating applicators, and the subsequent collection and transmission of the paint/solvent mixture to reclamation or recovery system. The collection and transmission systems would potentially be subject to the requirements of subparts BB. To avoid duplication, and because any potential for air releases from these sources are relatively small, we are proposing that if such a collection, transmission, and reclamation or recovery system is located at a facility subject to this proposed NESHAP, then it is exempt from the requirements of subparts BB of 40 CFR parts 264 and 265.

As stated elsewhere in this preamble, the HAP emissions from these sources are relatively small in comparison with the coating application, drying, and curing. Measurements made by industry indicate that emissions of VOC would be at least two orders of magnitude less than concentrations that would meet the definition of a leak under subparts BB of 40 CFR parts 264 and 265. Additionally, because the mixture is usually sold to a solvent recycler, the industry has an incentive to capture as much of the solvent as possible, and would therefore want to repair any leaks as quickly as possible.

In addition to the coating operations covered under the proposed NESHAP, some automobile and light-duty truck facilities also have separate, non-body plastic parts coating operations or separate, non-body metal parts coating operations. Purges from these separate, non-body plastic parts coating operations and separate, non-body metal parts coatings operations are analogous to those for automobile and light-duty truck body coatings and would also be exempt from the requirements of subparts BB of 40 CFR parts 264 and 265, if the operations occur in the same facility as the automobile and light-duty truck body coating. Many of the coatings applied to separate, non-body plastic and separate, non-body metal parts are similar in composition to those applied to automobile and light-duty truck bodies. The purged materials are conveyed to waste tanks in the same fashion as the purged materials from automobile and light-duty truck body coating operations.

B. What Is the Relationship to Other Rules?

Affected sources subject to the proposed rule may also be subject to other rules. Automobile and light-duty truck surface coating operations that began construction, reconstruction, or modification after October 5, 1979 are subject to new source performance standards (NSPS) under 40 CFR part 60, subpart MM. That rule limits emissions of volatile organic compounds (VOC). The EPA has also published control techniques guidelines which establish reasonably available control technologies for limiting VOC emissions from automobile and light-duty truck surface coating operations. Additional VOC emission limitations may also apply to these facilities through conditions incorporated in State operating permits and permits issued under authority of title V of the CAA. Facilities in this subcategory may also be subject to various emission limitations pursuant to State air toxics rules.

An automobile and light-duty truck surface coating facility may be subject to other NESHAP. Rules are presently under development which will limit emissions from coating operations conducted on separate, non-body miscellaneous metal parts and separate, non-body plastic parts and products. Coating of parts (such as automobile bumpers, fascias, brackets, etc.) for subsequent attachment to vehicle bodies would be subject to one or more of these rules, as would collocated aftermarket replacement part coating operations. Facilities may also be subject to other rules relating to collocated equipment such as foundries and boilers.

The capture, transmission, and storage of purge materials from coating equipment may also be subject to the RCRA Air Emission Standards for Equipment Leaks under subparts BB of 40 CFR parts 264 and 265. Those regulations apply to equipment that contains or contacts RCRA hazardous waste with organic concentrations of at least 10 percent by weight. To avoid such possible duplication, we are proposing to exempt such equipment from subparts BB if it is located at a

facility subject to this proposed NESHAP.

C. What Are the Primary Sources of Emissions and What Are the Emissions?

HAP emission sources.
Emissions from coating application, drying, and curing account for most of the HAP emissions from automobile and light-duty truck surface coating operations. The remaining emissions are primarily from cleaning of booths and application equipment and purging of spray equipment. In most cases, HAP emissions from surface preparation, storage, handling, and waste/wastewater operations are relatively small.

Organic HAP.
Available emission data collected during the development of the proposed NESHAP show that the primary organic HAP emitted from automobile and light-duty truck surface coating operations are toluene, xylene, glycol ethers, MEK, MIBK, ethylbenzene, and methanol. These compounds account for over 95 percent of the nationwide HAP emissions from this source category.

Inorganic HAP.
Based on information reported during the development of the proposed NESHAP, lead, manganese, and chromium are contained in some of the coatings used by this source category but are not likely to be emitted due to the coating application techniques used. No inorganic HAP were reported in thinners or cleaning materials. Most of the inorganic HAP components remain as solids in the dry coating film on the parts being coated, are collected by the circulating water under the spray booth floor grates, or are deposited on the walls, floor, and grates of the spray booths and other equipment in which they are applied. Therefore, inorganic HAP emission levels are expected to be very low and have not been quantified.

D. What Is the Affected Source?

We define an affected source as a stationary source, group of stationary sources, or part of a stationary source to which a specific emission standard applies. The proposed rule for automobile and light-duty truck surface coating defines the affected source as all of the equipment used to apply coating to new automobile or new light-duty truck bodies or collections of body parts for new automobiles or new light-duty trucks and to dry or cure the coating after application; all storage containers and mixing vessels in which vehicle body coatings, thinners, and cleaning materials are stored or mixed; all manual and automated equipment and containers used for conveying vehicle body coatings, thinners, and cleaning materials; and all storage containers and all manual and automated equipment and containers used for conveying waste materials generated by an automobile and light-duty truck surface coating operation.

The affected source does not include research or laboratory equipment or janitorial, building, and facility maintenance operations.

E. What Are the Emission Limits, Operating Limits, and Other Standards?

Emission limits.
We are proposing to limit organic HAP emissions from each new or reconstructed automobile and light-duty truck surface coating facility using the emission limits in Table 2 of this preamble.

Table 2.—Emission Limits for New or Reconstructed Affected Sources (monthly average)

Operation
Limit

Combined electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive operation
0.036 kilogram (kg) (0.30 pound (lb)) organic HAP/liter (HAP/gallon (gal)) of coating solids deposited).

Combined primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive operation (for sources meeting the operating limits of § 63.3092(a) and (b))
0.060 kg (0.50 lb organic HAP/1iter (HAP/gal) of coating solids deposited).

Adhesives and sealers, other than glass bonding adhesive
0.010 kg/kg (lb/lb) of material used.

Deadener
0.010 kg/kg (lb/lb) of material used.

We are proposing to limit organic HAP emissions from each existing automobile and light-duty truck surface coating facility using the emission limits in Table 3 of this preamble.

Table 3.—Emission Limits for Existing Affected Sources (monthly average)

Operation
Limit

Combined electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive operation
0.072 kg (0.60 lb) organic HAP/liter (HAP/gal) of coating deposited.

Combined primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive operation (for sources meeting the operating limits of § 63.3092(a) and (b))
0.132 kg (1.10 lb) organic HAP/liter (HAP/gal) of coating solids deposited.

Adhesives and sealers other than glass bonding adhesive
0.010 kg/kg (lb/lb) of material used.

Deadener.
0.010 lb/lb (kg/kg) of material used.

You would calculate emissions from combined electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive operations, or from combined primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive operations using the procedures in the proposed rule, which account for variable organic HAP contents of the materials applied in each month, as well as transfer efficiency and overall efficiencies of any capture systems and control devices in use. You would average organic HAP contents of other materials used on a monthly basis to determine separately those emissions from sealers and adhesives (other than glass bonding adhesive), and deadeners.

Operating limits.
If you use an emission capture and control system to reduce emissions, the proposed operating limits would apply to you. These proposed operating limits are site-specific parameter limits you determine during the initial performance test of the system. For capture systems, you would identify the parameter(s) to monitor and establish the limits and monitoring procedures. For thermal and catalytic oxidizers, you would establish temperature limits. For solvent recovery systems, you would

monitor the outlet concentration or carbon bed temperature and the amount of steam or nitrogen used to desorb the bed. All operating limits must reflect operation of the capture and control system during a performance test that demonstrates achievement of the emission limit during representative operating conditions.

Work practice standards.
You would have to 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 all coating operations for which emission limits are proposed. The plan would have to specify practices and procedures to ensure that, at a minimum, the following elements are implemented:

• All organic-HAP-containing coatings, thinners, cleaning materials, and waste materials must be stored in closed containers.

• The risk of spills of organic-HAP-containing coatings, thinners, cleaning materials, and waste materials must be minimized.

• Organic-HAP-containing coatings, thinners, cleaning materials, and waste materials must be conveyed from one location to another in closed containers or pipes.

• Mixing vessels, other than day tanks equipped with continuous agitation systems, which contain organic-HAP-containing coatings and other materials must be closed except when adding to, removing, or mixing the contents.

• Emissions of organic HAP must be minimized during cleaning of storage, mixing, and conveying equipment.

You would also have to develop and implement a work practice plan to minimize organic HAP emissions from cleaning and from purging of equipment associated with all coating operations for which emission limits are proposed. The plan would have to specify practices and procedures to ensure that emissions of HAP from the following operations are minimized:

• Vehicle body wiping;

• Coating line purging;

• Flushing of coating systems;

• Cleaning of spray booth grates;

• Cleaning of spray booth walls;

• Cleaning of spray booth equipment;

• Cleaning external spray booth areas; and

• Other housekeeping measures (
e.g.
, keeping solvent-laden rags in closed containers.)

General Provisions.
The General Provisions (40 CFR part 63, subpart A) also would apply to you as outlined in table 2 of the proposed rule. The General Provisions codify certain procedures and criteria for all 40 CFR part 63 NESHAP. The General Provisions contain administrative procedures, preconstruction review procedures for new sources, and procedures for conducting compliance-related activities such as notifications, recordkeeping and reporting, performance testing, and monitoring. The proposed rule refers to individual sections of the General Provisions to emphasize key sections that you should be aware of. However, unless specifically overridden in table 2 of the proposed rule, all of the applicable General Provisions requirements would apply to you.

F. What Are the Testing and Initial Compliance Requirements?

Compliance dates.
Existing affected sources would have to be in compliance with the final standards no later than 3 years after the effective date. The effective date is the date on which the final rule is published in the
Federal Register
. New and reconstructed sources would have to be in compliance upon startup of the affected source or by the effective date of the final rule, whichever is later.

Compliance with the emission limits is based on a monthly organic HAP emission rate. The initial compliance period, therefore, is the 1-month period beginning on the compliance date. If the compliance date occurs on any day other than the first day of a month, then the initial compliance period begins on the compliance date and extends through the end of that month plus the following month. We have defined “month” as a calendar month or a pre-specified period of 28 to 35 days to allow for flexibility at sources where data are based on a business accounting period.

Being “in compliance” means that the owner or operator of the affected source meets all the requirements of the proposed rule to achieve the emission limit(s) and operating limits by the end of the initial compliance period, and that the facility is operated in accordance with the approved work practice plans. At the end of the initial compliance period, the owner or operator would use the data and records generated to determine whether or not the affected source is in compliance for that period. If it does not meet the applicable limit(s), then it is out of compliance for the entire initial compliance period.

Emission limits.
Compliance with the emission limit for combined electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive, or the emission limit for combined primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive would be based on mass organic HAP emissions per volume of applied coating solids as calculated monthly using the procedures in the proposed rule. Compliance with the emission limits for adhesives and sealers (other than glass bonding adhesive) and deadener would be based on mass average organic HAP content of materials used each month.

Electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive.
Compliance with this emission limit, or if eligible, with the emission limit for combined primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive, is based on the calculations in the proposed rule. You may also use the guidelines presented in “Protocol for Determining Daily Volatile Organic Compound Emission Rate of Automobile and Light-Duty Truck Topcoat Operations,” EPA-450/3-88-018 (docket A-2001-22).

To determine the organic HAP content, the volume solids, and the density of the coatings and thinners, you could rely on manufacturer's data, results from the test methods listed below, or alternative test methods for which you get EPA approval on a case-by-case basis according to the NESHAP General Provisions in 40 CFR 63.7(f). However, if there is any inconsistency between the test results and manufacturer's data, the test results would prevail for compliance and enforcement purposes.

• For organic HAP content, use Method 311 of 40 CFR part 63, appendix A.

• The proposed rule allows you to use nonaqueous volatile matter as a surrogate for organic HAP. If you choose this option, then use Method 24 of 40 CFR part 60, appendix A.

• For volume fraction of coating solids, use either ASTM Method D2697-86 (1968) or ASTM Method D6093-97.

• For density, use ASTM Method D1475-98 or information from the supplier or manufacturer of the material. For each emission capture and control system that you use, you would:

• Conduct an initial performance test to determine the overall control efficiency of the equipment (described below) and to establish operating limits to be achieved on a continuous basis (also described below). The performance test would have to be completed no later than the compliance date. You would also need to schedule it in time to

obtain the results for use in completing your initial compliance determination for the initial compliance period.

The overall control efficiency for a capture and control system would be demonstrated based on emission capture and reduction efficiency. To determine the capture efficiency, you would either verify the presence of a permanent total enclosure using EPA Method 204 of 40 CFR part 51; measure the capture efficiency using either EPA Method 204A through F of 40 CFR part 51 or appendix A of 40 CFR part 63, subpart KK; or use the panel test procedures in ASTM Method D5087-91 (1994), ASTM Method D6266-00a, or the guidelines presented in “Protocol for Determining Daily Volatile Organic Compound Emission Rate of Automobile and Light-Duty Truck Topcoat Operations,” EPA-450/3-88-018 (docket A-2001-22). If you have a permanent total enclosure and you route all exhaust gases from the enclosure to a control device, then you would assume 100 percent capture. For panel testing, the coatings used may be grouped based on similar appearance characteristics (
e.g.
, solid color or metallic), processing sequences, and dry film thicknesses. One coating from each group can be tested to represent all of the coatings in that group.

To determine the emission reduction efficiency of the control device, you would conduct measurements of the inlet and outlet gas streams. The test would consist of three runs, each run lasting 1 hour, using the following EPA Methods in 40 CFR part 60, appendix A:

• Method 1 or 1A for selection of the sampling sites.

• Method 2, 2A, 2C, 2D, 2F, or 2G to determine the gas volumetric flow rate.

• Method 3, 3A, or 3B for gas analysis to determine dry molecular weight.

• Method 4 to determine stack moisture.

• Method 25 or 25A to determine organic volatile matter concentration. Alternatively, any other test method or data that have been validated according to the applicable procedures in Method 301 of 40 CFR part 63, appendix A, and approved by the Administrator, could be used.

You would be required to determine the transfer efficiency for primer-surfacer and topcoat materials using ASTM Method D5066-91 (2001) or the guidelines presented in “Protocol for Determining Daily Volatile Organic Compound Emission Rate of Automobile and Light-Duty Truck Topcoat Operations,” EPA-450/3-88-018 (docket A-2001-22). These guidelines include provisions for testing representative coatings instead of testing every coating. You may assume 100 percent transfer efficiency for electrodeposition primer coatings, glass bonding primers, and glass bonding adhesives. For final repair coatings, you may assume 40 percent transfer efficiency for air atomized spray and 55 percent transfer efficiency for electrostatic spray and high volume, low pressure spray.

The monthly emission rate, in terms of mass of organic HAP emitted per volume of coating solids deposited, is determined in accordance with the procedures in the proposed rule. These procedures incorporate the volume, organic HAP content, and volume solids content of each coating applied, as well as the transfer efficiency for the coatings and spray equipment used, and the overall control efficiency for controlled booths or bake ovens and other controlled emission points.

Adhesives and sealers, and deadener.
Compliance with emissions limits for adhesives and sealers (other than windshield materials) would be based on the monthly mass average organic HAP content of all materials of this type used during the compliance period. Compliance with emission limits for deadener would be based on the monthly mass average organic HAP content of all materials of this type used during the compliance period.

Operating limits.
As mentioned above, you would establish operating limits during the initial performance test of an emission capture and control system. The operating limit is defined as the minimum or maximum (as applicable) value achieved for a control device or process parameter during the most recent performance test that demonstrated compliance with the emission limit.

The proposed rule specifies the parameters to monitor for the types of control systems commonly used in the industry. You would be required to install, calibrate, maintain, and continuously operate all monitoring equipment according to manufacturer's specifications and ensure that the continuous parameter monitoring systems (CPMS) meet the requirements in § 63.3168 of the proposed rule. If you use control devices other than those identified in the proposed rule, you would submit the operating parameters to be monitored to the Administrator for approval. The authority to approve the parameters to be monitored is retained by EPA and is not delegated to States.

If you use a thermal or catalytic oxidizer, you would continuously monitor temperature and record it at least every 15 minutes. For thermal oxidizers, the temperature monitor is placed in the firebox or in the duct immediately downstream of the firebox before any substantial heat exchange occurs. The operating limit would be the average temperature measured during the performance test and for each 3-hour period, the average temperature would have to be at or above this limit. For catalytic oxidizers, temperature monitors are placed immediately before and after the catalyst bed. The operating limit would be the average temperature increase across the catalyst bed during the performance test and for each 3-hour period, the average temperature increase would have to be at or above this limit. As an alternative for catalytic oxidizers, you may monitor the temperature immediately before the catalyst bed and develop and implement an inspection and maintenance plan.

If you use a solvent recovery system, then you would either: (1) Continuously monitor the outlet concentration of organic compounds, and the operating limit would be the average organic compound outlet concentration during the performance test (for each 3-hour period, the average concentration would have to be below this limit); or (2) monitor the carbon bed temperature after each regeneration and the total amount of steam or nitrogen used to desorb the bed for each regeneration, in which case the operating limits would be the carbon bed temperature (not to be exceeded) and the amount of steam or nitrogen used for desorption (to be met as a minimum).

If you use a capture and control system to meet the proposed standards, you would have to meet operating limits for the capture system. If the emission capture system is a permanent total enclosure, you would be required to establish that the direction of flow was into the enclosure at all times. In addition, you would have to meet an operating limit of either an average facial velocity of at least 61 meters per minute (200 feet per minute) through all natural draft openings in the enclosure, or a minimum pressure drop across the enclosure of at least 0.018 millimeter water (0.007 inch water), as established by Method 204 of appendix M to 40 CFR part 51.

If the emission capture system was not a permanent total enclosure, you would have to establish either the average volumetric flow rate or the duct static pressure in each duct between the capture device and the add-on control device inlet during the performance test. Either the average volumetric flow rate would have to be maintained above the operating limit for each 3-hour period or the average duct static pressure would

have to be maintained above the operating limit for each 3-hour period.

Work practice standards.
You would have to develop and implement two site-specific work practice plans. One plan would address practices to minimize organic HAP emissions from storage, mixing, and conveying of coatings, thinners, and cleaning materials used in operations for which emission limits are established, as well as the waste materials generated from these operations. A second site-specific work practice plan would address practices to minimize emissions from cleaning operations and purging of coating equipment.

The plans would have to address specific types of potential organic HAP emission points and are subject to approval of the Administrator. Deviations from approved work practice plans would be reported semiannually.

G. What Are the Continuous Compliance Provisions?

Emission limits.
Continuous compliance with the emission limit for combined electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive, or if eligible, the emission limit for combined primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive, would be based on monthly calculations following the procedures in the proposed rule. These procedures take into account the amount of each coating used, the organic HAP and volume solids content of each coating used, the transfer efficiency of each coating application system, and the organic HAP abatement from each capture and control system, and provide for calculating monthly mass organic HAP emissions per volume of coating solids deposited.

Continuous compliance with the emission limits for adhesives and sealers (other than components of the windshield adhesive system), and deadener is based on the monthly average mass organic HAP concentration of all materials applied in each category.

Operating limits.
If you use an emission capture and control system, the proposed rule would require you to achieve on a continuous basis the operating limits you establish during the performance test. If the continuous monitoring shows that the system is operating outside the range of values established during the performance test, then you have deviated from the established operating limits.

If you operate a capture and control system that allows emissions to bypass the control device, you would have to demonstrate that HAP emissions from each emission point within the affected source are being routed to the control device by monitoring for potential bypass of the control device. You may choose from the following four monitoring procedures:

(1) Flow control position indicator to provide a record of whether the exhaust stream is directed to the control device;

(2) Car-seal or lock-and-key valve closures to secure the bypass line valve in the closed position when the control device is operating;

(3) Valve closure continuous monitoring to ensure any bypass line valve or damper is closed when the control device is operating; or

(4) Automatic shutdown system to stop the coating operation when flow is diverted from the control device.

If the continuous control device bypass monitoring shows that the control device is bypassed, then you have deviated from the established operating limits.

Operations during startup, shutdown, and malfunction.
When using an emission capture and control system for compliance, you would be required to develop and operate according to a startup, shutdown, and malfunction plan during periods of startup, shutdown, and malfunction of the capture and control system.

Work practice standards.
You would be required to operate your facility in accordance with your approved site-specific work practice plans at all times.

H. What Are the Notification, Recordkeeping, and Reporting Requirements?

You are required to comply with the applicable requirements in the NESHAP General Provisions, subpart A of 40 CFR part 63, as described in Table 2 of the proposed rule. The General Provisions notification requirements include: initial notifications, notification of performance test if you are complying by using a capture and control system, notification of compliance status, and additional notifications required for affected sources with continuous monitoring systems. The General Provisions also require certain records and periodic reports.

Initial notifications.
If the standards apply to you, you must send a notification to the EPA Regional Office in the region where your facility is located and to your State agency at least 1 year before the compliance date for existing sources, and within 120 days after the date of initial startup for new and reconstructed sources, or 120 days after publication of the final rule in the
Federal Register
, whichever is later. That report notifies us and your State agency that you have an existing facility that is subject to the proposed standards or that you have constructed a new facility. Thus, it allows you and the permitting authority to plan for compliance activities. You would also need to send a notification of planned construction or reconstruction of a source that would be subject to the proposed rule and apply for approval to construct or reconstruct.

Notification of performance test.
If you demonstrate compliance by using a capture and control system for which you do not conduct a monthly liquid-liquid material balance, you would conduct a performance test no later than the compliance date for your affected source. You must notify us (or the delegated State or local agency) at least 60 calendar days before the performance test is scheduled to begin as indicated in the General Provisions for the NESHAP.

Notification of compliance status.
You would send us a notification of compliance status within 30 days after the end of the initial compliance demonstration. In the notification, you would certify whether the affected source has complied with the proposed standards; summarize the data and calculations supporting the compliance demonstration; describe how you will determine continuous compliance; and for capture and control systems for which you conduct performance tests, provide the results of the tests. Your notification would also include the measured range of each monitored parameter and the operating limits established during the performance test, and information showing whether the source has achieved its operating limits during the initial compliance period.

Recordkeeping requirements.
The proposed rule would require you to collect and keep records according to certain minimum data requirements for the CPMS. Failure to collect and keep the specified minimum data would be a deviation that is separate from any emission limit, operating limit, or work practice requirement. You would be required to keep records of reported information and all other information necessary to document compliance with the proposed rule for 5 years. As required under the General Provisions, records for the 2 most recent years must be kept on-site; the other 3 years' records may be kept off-site. Records pertaining to the design and operation of the control and monitoring equipment must be kept for the life of the equipment.

You would have to keep the following records:

• A current copy of information provided by materials suppliers such as manufacturer's formulation data or test data used to determine organic HAP or VOC content, solids content, and quantity of the coatings and thinners applied.

• All documentation supporting initial notifications and notifications of compliance status.

• The occurrence and duration of each startup, shutdown, or malfunction of the emission capture and control system.

• All maintenance performed on the emission capture and control system.

• Actions taken during startup, shutdown, and malfunction that are different from the procedures specified in your startup, shutdown, and malfunction plan.

• All information necessary to demonstrate conformance with your startup, shutdown, and malfunction plan when the plan procedures are followed.

• Each period during which a CPMS is malfunctioning or inoperative (including out-of-control periods).

• All required measurements needed to demonstrate compliance with the standards.

• All results of performance tests.

• Data and documentation used to determine capture system efficiency or to support a determination that the system is a permanent total enclosure.

• Required work practice plans and documentation to support compliance with the provisions of these plans.

Deviations, as determined from these records, would need to be recorded and also reported. A deviation is any instance when any requirement or obligation established by the proposed rule, including but not limited to the emission limits, operating limits, and work practice standards, is not met.

If you use a capture and control system to reduce organic HAP emissions, you would have to make your startup, shutdown, and malfunction plan available for inspection if the Administrator requests to see it. It would stay in your records for the life of the affected source or until the source is no longer subject to the proposed standards. If you revise the plan, you would need to keep the previous superceded versions on record for 5 years following the revision.

Periodic reports.
Each reporting year is divided into two semiannual reporting periods. If no deviations occur during a semiannual reporting period, you would submit a semiannual report stating that the affected source has been in continuous compliance. If deviations occur, you would need to include them in the report as follows:

• Report each deviation from each applicable monthly emission limit.

• Report each deviation from the work practice plan.

• If you are complying by using a thermal oxidizer, report all times when a 3-hour average temperature is below the operating limit.

• If you are complying by using a catalytic oxidizer, report all times when a 3-hour average temperature increase across the catalyst bed is below the operating limit.

• If you are complying by using oxidizers or solvent recovery systems, report all times when the value of the site-specific operating parameter used to monitor the capture system performance was greater than or less than (as appropriate) the operating limit established for the capture system.

• Report other specific information on the periods of time the deviations occurred.

You would also have to send us explanations in each semiannual report if a change occurs that might affect your compliance status.

Other reports.
You would be required to submit other reports, including those for periods of startup, shutdown, and malfunction of the emission capture and control system. If the procedures you follow during any startup, shutdown, or malfunction are inconsistent with your plan, you would report those procedures with your semiannual reports in addition to immediate reports required by 40 CFR 63.10(d)(5)(ii).

III. Rationale for Selecting the Proposed Standards

A. How Did We Select the Source Category?

Automobile and light-duty truck surface coating is a source category that is on the list of source categories to be regulated because it contains major sources which emit or have the potential to emit at least 9.7 Mg (10 tons) of any one HAP or at least 22.7 Mg (25 tons) of any combination of HAP annually. The proposed rule would control HAP emissions from both new and existing major sources. Area sources are not being regulated under this proposed rule.

The automobile and light-duty truck surface coating source category as described in the listing includes any facility engaged in the surface coating of new automobile and light-duty truck bodies. Excluded from this source category are automobile customizers, body shops, and refinishers. For purposes of this proposed rule, we are defining the source category to include the application of electrodeposition primer, primer-surfacer, topcoat (including basecoat and clear coat), final repair, glass bonding primer, glass bonding adhesive, sealer, adhesive, and deadener; all storage containers and mixing vessels in which the above listed coatings, thinners, and cleaning materials associated with the above listed coatings are stored or mixed; all manual and automated equipment and containers used for conveying coatings, thinners, and cleaning materials; and all storage containers and manual and automated equipment used for conveying waste materials generated by a coating operation.

We intend the source category to include facilities for which the surface coating of automobiles and light-duty trucks or automobile and light-duty truck bodies is either their principal activity or is an integral part of an automobile or light-duty truck assembly plant.

The initial listing for this source category included the surface coating of body parts for inclusion in new vehicles. As provided in the initial source category listing notice (57 FR 31576, July 16, 1992):

. . . the Agency recognizes that these descriptions [in the initial list], like the list itself, may be revised from time to time as better information becomes available. The Agency intends to revise these descriptions as part of the process of establishing standards for each category. Ultimately, a definition of each listed category, or subsequently listed subcategories, will be incorporated in each rule establishing a NESHAP for a category.

Some automobile assembly plants operate separate lines which apply coatings to parts such as bumpers, fascias, and brackets for attachment to separately coated vehicle bodies. However, since most plastic and metal parts that are attached to coated vehicle bodies are produced in separate facilities, we have decided that it makes more sense to regulate these off-line plastic and metal parts coating operations under separate NESHAP for surface coating of plastic parts and products and miscellaneous metal parts because of the substantially different equipment that may be used to coat these parts and for consistency with the NSPS and other air pollution control regulations affecting these coating operations.

The source category does not include research or laboratory facilities or janitorial, building, and facility maintenance operations.

B. How Did We Select the Regulated Pollutants?

Organic HAP.
Available emission data collected during the development of the proposed NESHAP show that the primary organic HAP emitted from automobile and light-duty truck surface coating operations are toluene, xylene, glycol ethers, MEK, MIBK, ethylbenzene and methanol. These compounds account for over 95 percent of this category's nationwide organic HAP emissions. Because coatings used in automobile and light-duty truck surface coating contain many combinations of these and other organic HAP, it is not practical to regulate them individually. Therefore, the proposed standards would regulate emissions of all organic HAP.

Inorganic HAP.
Based on information reported during the development of the proposed NESHAP, inorganic HAP contained in the coatings used by this source category include lead, manganese, and chromium compounds. There is limited opportunity for these HAP to be emitted into the ambient air. The lead compounds are present in the electrodeposition primers. This technique would not typically generate air emissions of these compounds which are in the coating solids. Once the coating solids are deposited on the substrate, they remain on the substrate and are not emitted during cure of the coating. Therefore, we conclude that there are limited or no air emissions of lead compounds. Based on information reported during the development of the proposed NESHAP, a small amount of chromium compounds are contained in a few of the coatings used by this source category. Because these inorganic compounds are in the coating solids, they are retained on the substrate to which they are applied, and the only opportunity for them to enter the ambient air is if they are spray-applied. Because of the atomization of the coating during spray application, inorganic compounds become airborne, and they are either deposited on the substrate, collected by the circulating water under the spray booth floor grates, adhere to the surrounding walls and other surfaces in the area, or enter the air and become susceptible to transport to other areas in the building or outside into the ambient air. The data available to EPA indicate that the facilities in this source category that use spray application techniques sometimes apply coatings that contain inorganic HAP compounds, including small quantities of chromium oxide. Overspray, including that containing inorganic HAP, is controlled to an extremely high level by down-draft impingement in circulating sub-grate water systems.

C. How Did We Select the Affected Source?

In selecting the affected sources for MACT standards, our primary goal is to ensure that MACT is applied to HAP-emitting operations or activities within the source category or subcategory being regulated. The affected source also serves to distinguish where new source MACT applies under a particular standard. Specifically, the General Provisions in subpart A of 40 CFR part 63 define the terms “construction” and “reconstruction” with reference to the term “affected source” (40 CFR 60.2) and provide that new source MACT applies when construction or reconstruction of an affected source occurs (40 CFR 60.5). The collection of equipment and activities evaluated in determining MACT (including the MACT floor) is used in defining the affected source. Some source categories are comprised of HAP-emitting equipment and activities that are independent, have no functional interactions at the process level, and are not related to each other in terms of emission control. In these cases, it is reasonable from a MACT implementation perspective to have separate, narrowly defined affected sources for purposes of focusing MACT applicability. An implication of a narrow definition of affected source is that new source MACT requirements could be triggered more frequently as equipment is replaced (potential “reconstruction”) or facilities are expanded (potential “construction”) than with a broader definition of affected source, such as some collection of equipment or even the entire facility. This approach is sometimes appropriate based on consideration of emission reductions, cost impacts, and implementation factors.

When a MACT standard is based on total facility emissions, we select an affected source based on the entire facility as well. This approach for defining the affected source broadly is particularly appropriate for industries where a plantwide emission standard provides the opportunity and incentive for owners and operators to utilize control strategies that are more cost effective than if separate standards were established for each emission point within a facility.

The affected source in the automobile and light-duty truck surface coating source category for which MACT standards are being proposed is the equipment used for electrodeposition primer, primer-surfacer, topcoat (including basecoat and clear coat), final repair, glass bonding primer, glass bonding adhesive, sealer, adhesive, and deadener; as well as storage containers and mixing vessels in which coatings, thinners, and cleaning materials are stored and mixed; all manual and automated equipment 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 for which an emission limit is proposed. Standards for new sources apply to newly constructed or reconstructed paintshops. All of the organic HAP-emitting coating operations covered by this source category occur within the area of an automobile assembly plant referred to as the paint shop, except for the operations related to glass installation (glass bonding primer, glass bonding adhesive, and pre-installation cleaning) and certain off-line final repair operations. All existing affected sources are located at automobile assembly plants. Other collocated operations at automobile assembly plants may be subject to other NESHAP, including NESHAP currently under development for source categories such as miscellaneous metal parts coating and plastic parts and products coating.

Additional information on the operations at automobile and light-duty truck surface coating facilities that were selected for regulation and other operations that are conducted at automobile assembly plants are included in the docket for the proposed standards.

D. How Did We Determine the Basis and Level of the Proposed Standards for Existing and New Sources?

After we identify the specific source categories or subcategories of sources to regulate under section 112 of the CAA, we must develop MACT standards for each category or subcategory. Section 112 establishes a minimum baseline or “floor” for standards. For new sources in a category or subcategory, the standards cannot be less stringent than the emission control that is achieved in practice by the best-controlled similar source (section 112(d)(3)). The standards for existing sources can be less stringent than standards for new sources, but they cannot be less stringent than the average emission limitation achieved by the best-performing 12 percent of existing sources for which the Administrator has emissions information (or the best-performing five sources for categories or

subcategories with fewer than 30 sources).

Electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive.
All 59 facilities in the source category that were in operation in 1997 or 1998 responded to an information collection request (ICR). (Several facilities did not have operating paint shops during this period, but submitted information pertaining to their applications of sealers and adhesives in the assembly process.) Two facilities that presently track their usage and emissions on a line-by-line basis submitted two sets of data each. The responses contained data on the mass of organic HAP emissions per volume of coating solids deposited for each month of a calendar year for electrodeposition primer, primer-surfacer, and topcoat operations; and additional information on final repair, glass bonding primer, and glass bonding adhesive. Final repair and glass bonding materials are functionally tied to the electrodeposition primer, primer-surfacer, and topcoat materials. Final repair materials must be compatible with these other coatings and must provide an exact color and appearance match. Glass bonding materials also must be compatible with these other coatings. The choice of glass bonding materials is highly dependent on the performance characteristics of and interaction with these other coatings. Glass bonds must meet safety requirements issued by the National Highway Transportation Safety Administration. Therefore, we have included final repair, glass bonding primer, and glass bonding adhesive with electrodeposition primer, primer-surfacer, and topcoat.

In most cases, facilities calculated their monthly emissions from primer-surfacer and topcoat operations using a procedure that closely matched the procedure in “Protocol for Determining Daily Volatile Organic Compound Emission Rate of Automobile and Light-Duty Truck Topcoat Operations,” EPA-450/3-88-018 (docket A-2001-22). The calculations took into account the overall efficiency of capture systems and control devices, as well as the transfer efficiency of spray equipment used to apply coatings. In addition, the responses included the mass organic HAP content and the volume solids content of all materials added to the electrodeposition system on a monthly basis. Using the data, we ranked the facilities on the basis of mass of organic HAP emissions per volume of coating solids deposited on an annual basis. Several of the lowest emitting facilities did not apply full body primer-surfacer during the ICR reporting year (although these facilities as well as all other presently operating facilities do so currently). Since the data from these facilities did not represent the current and anticipated industry practices, we eliminated them from the ranking. We then identified the eight facilities with the lowest-organic-HAP emissions (from electrodeposition, primer-surfacer, and topcoat combined) per volume coating solids deposited. As four of the eight lowest emitting plants used a powder primer-surfacer application system which results in a much thicker film than a liquid application system, we adjusted the solids deposited volumes for the powder systems to reflect liquid primer surfacer thicknesses.

We then identified the month of the reporting year with the peak organic HAP emission rate for the eight facilities with the lowest annual emission rates. Since the proposed rule requires compliance each and every month, an emission limit based on the annual emissions would be unachievable by even the lowest emitting plants approximately 6 months of the year. Variations in colors or vehicles produced and the organic HAP contents of different basecoats and color-keyed primer-surfacers leads to unavoidable fluctuations in organic HAP emission rates, even with the same application equipment and capture and control devices in use. The average organic HAP emission rate for the peak month for the eight lowest emitting plants (as determined on an annual basis) was determined to be the MACT floor for a monthly compliance standard for combined electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive operations at existing plants.

We have also proposed a compliance demonstration option based on emissions from combined primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive operations for those plants with well controlled electrodeposition operations, or that use very low-organic-HAP materials in their electrodeposition primer operation. This was based on the emission rate from primer-surfacer and topcoat application at the eight lowest emitting plants. (The same plants as those with the lowest emission rates from electrodeposition, primer-surfacer, and topcoat combined.) The emission rate without electrodeposition is comparable to the proposed emission rate with electrodeposition when the lower-organic-HAP emissions per volume of coating solids deposited which result from including electrodeposition primer are considered.

The floor for new sources was based on the performance of the plant with the lowest annual emission rate. The peak monthly emission rate for this plant for the reporting year would represent the best consistently achievable emission rate for new sources.

Both the existing source MACT floor and the new source MACT floor are based on monthly compliance. All or nearly all automobile and light-duty truck surface coating facilities are subject to compliance with existing rules demonstrated by calculations based on monthly coating use. The ICR responses upon which the MACT determination was made provided data on a monthly basis. A 1-month time period is the shortest compliance period for which data are available to reliably determine MACT.

Adhesives and sealers (other than glass binding adhesive), and deadeners.
All facilities in the source category submitted responses to an ICR. The responses contained data on the mass used, and the mass fraction of organic HAP in each of the materials used during the reporting year. The average mass organic HAP content of the materials used throughout the reporting year was determined for each facility. The eight facilities with the lowest-average-organic-HAP content in each group (
i.e.
, adhesives and sealers were considered separately from deadeners) were determined. These facilities used materials with an average mass fraction of organic HAP of less than 0.01 kilogram (kg)/kg (pound (lb)/lb. Because of imprecision in analytical methods at this level, and because the organic HAP reported as zero for some materials at some facilities may have contained traces of organic HAP that were not reported to the facility by the material supplier, the MACT floor mass organic HAP content was determined to be 0.01 kg/kg (lb/lb). This is the lowest level for both new and existing facilities for which compliance could be reliably demonstrated. The proposed rule would require compliance to be demonstrated monthly on the basis of a mass average organic HAP content of the materials used. A shorter compliance time interval would result in excessive recordkeeping with little or no additional reduction in organic HAP emissions. If each and every material used within a particular group of materials meets the monthly average emission limit on an individual basis, then no calculations are required to demonstrate compliance.

Storage, mixing, and conveying of coatings, thinners, and cleaning

materials.

The proposed rule would regulate these operations in accordance with a site-specific work practice plan to be developed subject to approval by the Administrator and implemented by each new and existing source. We have no reliable data on the extent of emissions from these operations but believe them to be low.

Cleaning and equipment purging emissions.
While the responses to the ICR contain extensive (though in some cases inconsistent) data pertaining to the volumetric use and organic HAP content of cleaning and purging materials, a substantial but unknown fraction of the organic HAP emissions from cleaning and purging operations are captured and controlled. We have no reliable data that would enable us to determine an emission limit for these operations that would represent MACT level control. The proposed rule would regulate these operations in accordance with a site-specific work practice plan to be developed subject to approval by the Administrator and implemented by each new and existing source.

After the floors have been determined for new and existing sources in a source category or subcategory, we must set MACT standards that are technically achievable and no less stringent than the floors. Such standards must then be met by all sources within the category or subcategory. We identify and consider any reasonable regulatory alternatives that are “beyond-the-floor,” taking into account emission reduction, cost, non-air quality health and environmental impacts, and energy requirements. These alternatives may be different for new and existing sources because different MACT floors and separate standards may be established for new and existing sources.

The eight facilities with the lowest-organic-HAP emission rates from electrodeposition primer, primer-surfacer, and topcoat application employed a combination of various organic HAP emission limitation techniques, including the use of lower-organic-HAP electrodeposition primer materials, powder primer-surfacer, waterborne basecoats, lower-organic-HAP solvent based primer-surfacers, lower-organic-HAP solvent based basecoats and clearcoats, and improved capture and control systems. However, no single technology or combination of technologies representing a beyond-the-floor MACT was identified, nor did we identify any other available technologies which are not presently in use with the potential to decrease organic HAP emissions beyond-the-floor for either new or existing sources.

We expect that many existing plants will improve capture and control device efficiency as a means of compliance. Control options beyond-the-floor could involve even higher overall efficiencies. Because of the dilute nature of the organic HAP-containing streams available for capture, the cost of such a beyond-the-floor limit would exceed $40,000 per ton of incremental organic HAP controlled. We are not proposing beyond-the-floor limits at this time. Following a future analysis of residual risk, EPA may propose a beyond-the-floor emission limit, if it is found to be justified.

The facilities which presently use adhesives and sealers, and deadeners with the lowest-mass-organic-HAP contents would not be able to reliably demonstrate compliance with a standard more stringent than the floor level emission limit for these materials due to uncertainty in the analytical methods available and the expected inability or unwillingness of the suppliers of the materials to certify lower-organic-HAP contents.

A wide variety of techniques exist for reducing organic HAP emissions from mixing, storage, and conveying of coatings, thinners, and cleaning materials, and from cleaning and purging of equipment. Because we have no data upon which to establish a numerical organic HAP emission limit for these operations, we have proposed to regulate them through the development and implementation of site-specific work practice plans. The proposed rule identifies a number of potential emission control practices which must be considered, as applicable, in these work plans. Alternative practices which achieve equivalent or improved emission limitations are also permitted under the proposed rule. Because we are unable to reliably estimate the emissions reductions that will be achieved beyond the present baseline emissions from these operations, the work practices requirements may represent beyond-the-floor standards. We believe that the costs of implementing these work practices will be reasonable, as many of the same or equivalent practices would be required for control of VOC emissions under title V air permits.

In lieu of emission standards, section 112(h) of the CAA allows work practice standards or other requirements to be established if: (1) A pollutant cannot be emitted through a conveyance or capture system, or (2) measurement is not practicable due to technological and economic limitations. All automobile and light-duty truck surface coating facilities use some type of work practice measures to reduce HAP emissions from mixing, storage, conveying, and cleaning and purging as part of their standard operating procedures. They use these measures to decrease solvent usage and minimize exposure to workers. However, data to quantify accurately the emissions reductions achievable by the work practice measures are unavailable, and it is not feasible to measure emissions or enforce a numerical standard for emissions from these operations.

We selected MACT floor level standards for electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, glass bonding adhesive, sealer, and adhesive application, and deadener because we were unable to identify any specific technologies that would result in a lower level of emissions. We have proposed a more stringent emission limit for electrodeposition primer, primer-surfacer, and topcoat application for new sources. This more stringent limit is not appropriate for existing sources because of the difficulty, uncertainty, and in some cases, impossibility of retrofitting the best combination of emission limitation techniques to existing facilities, as well as the high cost associated with what would be a beyond-the-floor limit for existing facilities.

We believe the proposed standards for existing sources are achievable because they are presently being achieved by at least six existing sources. We believe the proposed standards for new sources are achievable because they are presently being achieved by the best performing facility in the source category.

We have proposed standards for which compliance would be demonstrated on a monthly basis. The data used to determine MACT for electrodeposition primer, primer-surfacer, and topcoat were based on organic HAP emission limits that were achieved by the best performing plants each month (during which production occurred) during the reporting year for the ICR responses. We used annual data to determine MACT for adhesives and sealers, and deadeners, but believe that monthly compliance is achievable because the standards are based on organic HAP per mass of material, or organic HAP per volume of material and we have no reason to believe that different materials are used at different times throughout the year.

E. How Did We Select the Format of the Proposed Standards?

Numerical emission standards are required by section 112 of the CAA unless we can justify that it is not

feasible to prescribe or enforce an emission standard, in which case a design, equipment, work practice, or operational standard can be set (section 112(h) of the CAA).

Formats considered.
We considered the following formats for allowable organic HAP emissions from the affected source: (1) Mass of organic HAP per unit weight or volume of coating, coating solids, or coating solids deposited; (2) mass of organic HAP per unit of production; (3) organic HAP concentration exiting a control device; (4) organic HAP emissions per unit surface area coated; and (5) percent reduction achieved by a capture system and control device. Each format is defined, and the major advantages and disadvantages are discussed below.

The first type of format considered would express the emission limitation as mass of organic HAP emissions per volume of coating, mass of coating solids, volume of coating solids, or volume of coating solids deposited. An advantage of this type of format is that it relates emissions to production levels, but in a more equitable way than one based on units of production. Also, an affected source would have flexibility in choosing among several compliance options to achieve a standard based on this type of format. This type of standard, when based on mass or volume of coating solids deposited, takes into account the transfer efficiency,
i.e.
, the fraction of coating solids used that actually adhere to the substrate.

A mass of HAP per volume of coating format (
i.e.
, kg HAP/liter (lb HAP/gallon (gal)) of coating) either for each coating or as an average across all coatings could be used. While this format is simple to understand and use, its main disadvantage is that it would not credit sources that switch to lower-emitting, higher-solids coatings. For example, a facility using a coating with a solids content of 40 percent and a HAP content of 3 lb/gal will use fewer pounds of HAP than a facility using a coating with a solids content of 20 percent and a HAP content of 2 lb/gal because the first facility will use 50 percent less coating than the second. A comparison of the emission potential of two coatings using a mass HAP per volume coating format cannot be made.

An alternative format is a mass HAP per volume of coating solids (
i.e.
, kg HAP/liter (lb HAP/gal) of coating solids). This format would adequately credit sources that converted conventional higher-HAP-solvent coatings to higher-solids coatings. The same is true for a format of mass HAP/mass of solids (
i.e.
, kg HAP/kg (lb HAP/lb) solids). For example, if a source were to increase the solids content of a coating and thereby decrease the quantity of coating used, either of these formats would properly credit the affected source's emissions reductions. However, there are potential drawbacks to the mass HAP/mass solids format. Such a standard does not take into account the sometimes considerable differences in coating solids densities. Either the mass HAP/mass solid or the mass HAP/volume solid formats can be restated to consider applied solids rather than solids contained in the coating to provide credit for application techniques with higher transfer efficiencies.

The second format considered is mass of organic HAP emissions per unit of production (
e.g.,
kg HAP per vehicle coated). Its major disadvantage is that the surface area of automobiles and light-duty trucks varies greatly.

The third format considered, a limit on the concentration of organic HAP in the exhaust from the control device would only apply to sources that use add-on control devices. This format for a standard is the easiest to enforce because direct emissions measurements can be made using Method 25 or 25A. However, the concentration of organic HAP emitted from the control device does not reflect total emissions because of the possibility of uncaptured emissions from the coating operation, nor does it limit total emissions because of the effect of varying the exhaust flow rates (
i.e.
, increasing dilution air). For example, two similar coating operations could produce the same amount of organic HAP yet have different inlet concentrations to the control device because of variations in capture of emissions from the coating operation and because of varying oven airflow rates. A standard based on outlet concentration would require the line with the higher concentration (lower airflow rate) to control more organic HAP emissions than the line with the lower inlet concentration. Because management of airflow rates is generally under the control of the operator, this format would not reflect the application of MACT for the coating operation. Furthermore, this format would limit the compliance options available to sources because it would not accommodate the use of either low-HAP content coatings and other materials, or the use of a combination of capture and control systems in conjunction with reduced-HAP coatings and other materials.

The fourth format, organic HAP emissions per unit surface area coated, provides flexibility in the selection of coating materials, the streams to be controlled, and the approach to capture and control. We requested surface area data for vehicles produced during the ICR reporting year and received data of this type from a number of respondents. The data that we received were incomplete, and the methods of estimating vehicle surface areas varied widely. In many cases, computer generated design drawings were analyzed to estimate surface areas. The algorithms used to make the estimates are unlikely to be consistent from manufacturer to manufacturer. While a standard in this format has some advantages, it would be difficult to establish MACT because of the inconsistent basis of the estimates.

The fifth format, percent reduction, would only apply to sources that use add-on control devices. This format is often the best choice when capture and control systems are widely used in the source category, and the achievable percent reduction over a wide range of operating conditions is predictable. The advantages of this format are that it would reflect MACT at all facilities, and the facilities would be allowed flexibility in the method selected for achieving the percent reduction. A disadvantage of the percent reduction format is that it does not credit improvements in the materials or processes. For example, reduction in the organic HAP content of a coating or in the amount of coating applied per unit of substrate manufactured would not be credited toward compliance. This might discourage development of low- or non-HAP coatings. Similar to the concentration format for a standard, this format also would not accommodate the use of either low-HAP content coatings and other materials or a combination of capture and control systems in conjunction with reduced-HAP coatings and other materials as a means of compliance.

Format selected.
We selected mass of HAP emitted per volume of coating solids deposited as the format for the proposed emission limit for electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive. All automobile and light-duty truck surface coating facilities presently calculate VOC emissions from primer-surfacer and topcoat application in this format and have recordkeeping systems in place to track coating usage, mass fraction of VOC, volume fraction of solids, and transfer efficiencies. Responses to the ICR were, for the most part, based on adaptions of these systems to calculate organic HAP emissions from both topcoat and primer

surfacer application. Only minor adjustments would be necessary to include electrodeposition coatings, as only two to four different materials are used for this process, and the transfer efficiency is essentially 100 percent. Such a format would be consistent with the information upon which MACT determination was based. This format gives credit for the use of low- or zero-organic-HAP coatings or high solids coatings in one or more application processes, as well as improved application techniques which result in higher transfer efficiencies for primer-surfacer and topcoat. This format would allow sources flexibility to use a combination of emission capture and control systems as well as low-HAP content coatings and other materials.

We selected mass of organic HAP per mass of coating as the format for the proposed standards for adhesives and sealers, and deadeners. These materials are applied with nearly 100 percent transfer efficiency in most cases and emissions from these materials are rarely, if ever, directed to add-on control devices.

F. How Did We Select the Testing and Initial Compliance Requirements?

We have proposed a compliance procedure for electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive. The procedure takes into account the volume of each coating used, its mass organic HAP content, volume solids content, and density, as well as the transfer efficiency and the overall efficiency of any add-on control devices. The procedure is modeled after the procedure in “Protocol for Determining Daily Volatile Organic Compound Emission Rate of Automobile and Light-Duty Truck Topcoat Operations,” EPA-450/3-88-018 (docket A-2001-22), presently used to demonstrate compliance with VOC emission limits for topcoat and primer-surfacer application at automobile and light-duty truck surface coating facilities.

We have proposed a monthly average mass organic HAP content determination to demonstrate compliance with the emission limits for adhesives and sealers, and deadeners.

Method 311 of 40 CFR part 63, appendix A, is the method developed by EPA for determining the HAP content of coatings and has been used in previous surface coating NESHAP. We have not identified any other methods that provide advantages over Method 311 for use in the proposed rule.

Method 24 of 40 CFR part 60, appendix A, is the method developed by EPA for determining the VOC content of coatings and can be used if you choose to determine the nonaqueous volatile matter content as a surrogate for organic HAP. In past rules, VOC emission control measures have been implemented in the coatings industry with Method 24 as the compliance method. We have not identified any other methods that provide advantages over Method 24 for use in the proposed rule.

The proposed requirements for determining volume solids would allow you to choose between calculating the value using either ASTM Method D2697-86 (1988) or ASTM Method D6093-97.

You may use information provided by your coating supplier instead of conducting the HAP, solids, and density determinations yourself. The above specified test methods will take precedence if there is any discrepancy between the result of the methods and information provided by your suppliers.

Capture and control systems.
If you use an emission capture and control system, you would be required to conduct an initial performance test of the system to determine its overall control efficiency. The overall control efficiency would be combined with the monthly HAP content of the coatings and other materials used in the affected source to derive the monthly HAP emission rate to demonstrate compliance with the standard for electrodeposition primer, primer-surfacer, topcoat, final repair, glass bonding primer, and glass bonding adhesive.

If you conduct a performance test, you would also determine parameter operating limits during the test. The test methods that the proposed rule would require for the performance test have been required for many industrial surface coating sources under NSPS in 40 CFR part 60 and NESHAP in 40 CFR part 63. We have not identified any other methods that provide advantages over these methods.

Work practices.
In the initial compliance report, you would certify that you have met the proposed work practice standards during the initial compliance period. You would also keep the records required to document your actions. These are minimal compliance requirements to ensure you are meeting the standards.

G.
How Did We Select the Continuous Compliance Requirements?

To ensure continuous compliance with the proposed emission limits and operating limits, the proposed rule would require continuous parameter monitoring of capture systems, add-on control devices, and recordkeeping. We selected the following requirements based on: reasonable cost, ease of execution, and usefulness of the resulting data to both the owners or operators and EPA for ensuring continuous compliance with the emission limits and operating limits.

We are proposing that certain parameters be continuously monitored for the types of capture and control systems commonly used in the industry. These monitoring parameters have been used in other standards for similar industries. The values of these parameters that correspond to compliance with the proposed emission limits are established during the initial or most recent performance test that demonstrates compliance. These values are your operating limits for the capture and control system.

You would be required to determine 3-hour average values for most monitored parameters for the affected source. We selected this averaging period to allow for normal variation of the parameter while ensuring that the control system is continuously operating at the same or better control level as during a performance test demonstrating compliance with the emission limits.

To demonstrate continuous compliance with the monthly emission limits, you would also need records of the quantity of coatings and other materials used and the data and calculations supporting your determination of their HAP content.

To demonstrate continuous compliance with the work practice standards, you would keep the associated records specified in your work practice plan, as required by the proposed rule, and comply with the associated reporting requirements.

H. How Did We Select the Notification, Recordkeeping, and Reporting Requirements?

You would be required to comply with the applicable requirements in the NESHAP General Provisions, subpart A of 40 CFR part 63, as described in Table 2 of the proposed rule. We evaluated the General Provisions requirements and included those we determined to be the minimum notification, reporting, and recordkeeping necessary to ensure compliance with, and effective enforcement of, the proposed standards.

I. How Did We Select the Compliance Date?

The proposed rule allows existing sources 3 years from the effective date of the final standards to demonstrate

compliance. This is the maximum compliance period permitted by the CAA. We believe that 3 years may be necessary for some affected sources to design, install, and test improved capture systems and control devices. Sources that adopt reformulated lower HAP coatings or powder coatings may also need 3 years to specify, adjust application equipment, and modify existing coating processes. New or reconstructed affected sources must comply immediately upon startup or the effective date of the proposed rule, whichever is later as required by the CAA.

IV. Summary of Environmental, Energy, and Economic Impacts

A. What Are the Air Quality Impacts?

The proposed rule would decrease HAP emissions from automobile and light-duty truck surface coating facilities from an estimated 10,000 tpy to 4,000 tpy. This represents a decrease of 6,000 tpy or 60 percent. The proposed rule would also decrease VOC by approximately 12,000 to 18,000 tpy. These values were calculated in comparison to baseline emissions reported to EPA by individual facilities for 1996 or 1997.

B. What Are the Cost Impacts?

The estimated total capital costs of compliance, including the costs of monitors, is $670 million. This will result in an additional annualized capital cost of $75 million compared to a baseline total capital expenditure of $4 to $5 billion per year.

The projected total annual costs, including capital recovery, operating costs, monitoring, recordkeeping, and reporting is $154 million per year. This represents less than one-tenth of 1 percent of the baseline industry revenues of $290 billion and just over 1.0 percent of baseline industry pre-tax earnings of $14 billion.

The cost analysis assumed that each existing facility would use, in the order presented, as many of the following four steps as necessary to meet the proposed emission limit. First, if needed, facilities that did not already control their electrodeposition primer bake oven exhaust would install and operate such control at an average cost of $8,200 per ton of HAP controlled. Next, if needed, facilities would reduce the HAP-to-VOC ratio of their primer-surfacer and topcoat materials to 0.3 to 1.0 at an average cost of $540 per ton of HAP controlled. Finally, if needed, facilities would control the necessary amount of primer-surfacer and topcoat spray booth exhaust at an average cost of $40,000 per ton of HAP controlled. For all four steps combined, the average cost is about $25,000 per ton of HAP controlled.

New facilities and new paint shops would incur little additional cost to meet the proposed emission limit. These facilities would already include bake oven controls and partial spray booth exhaust controls for VOC control purposes. New facilities might need to make some downward adjustment in the HAP content of their materials to meet the proposed emission limit.

C. What Are the Economic Impacts?

The EPA prepared an economic impact analysis to evaluate the primary and secondary impacts the proposed rule would have on the producers and consumers of automobiles and light-duty trucks, and society as a whole. The analysis was conducted to determine the economic impacts associated with the proposed rule at both the market and industry levels. Overall, the analysis indicates a minimal change in vehicle prices and production quantities.

Based on the estimated compliance costs associated with the proposed rule and the predicted changes in prices and production in the affected industry, the estimated annual social costs of the proposed rule is projected to be $161 million (1999 dollars). The social costs take into account changes in behavior by producers and consumers due to the imposition of compliance costs from the proposed rule. For this reason the estimated annual social costs differ from the estimated annual engineering costs of $154 million. Producers, in aggregate, are expected to bear $152 million annually in costs while the consumers are expected to incur the remaining $10 million in social costs associated with the proposed rule.

The economic model projects an aggregate price increase for the modeled vehicle classes of automobiles and light-duty trucks to be less than 1/100th of 1 percent as a result of the proposed standards. This represents at most an increase in price of $3.00 per vehicle. The model also projects that directly affected producers would reduce total production by approximately 1,400 vehicles per year. This represents approximately 0.01 percent of the 12.7 million vehicles produced by the potentially affected plants in 1999, the baseline year of analysis.

In terms of industry impacts, the automobile and light-duty truck manufacturers are projected to experience a decrease in pre-tax earnings of about 1 percent or $152 million. In comparison, total pre-tax earnings for the potentially affected plants included in the analysis exceeded $14 billion in 1999. The reduction in pre-tax earnings of 1 percent reflects an increase in production costs and a decline in revenues earned from a reduction in the quantity of vehicles sold. Through the market and industry impacts described above, the proposed rule would lead to a redistribution of profits within the industry. Some facilities (28 percent) are projected to experience a profit increase with the proposed rule; however, the majority (72 percent) that continue operating are projected to lose profits. No facilities are projected to close due to the proposed rule.

D. What Are the Non-Air Health, Environmental, and Energy Impacts?

Solid waste and water impacts of the proposed rule are expected to be negligible. Capture of additional organic HAP-laden streams and control of these streams with regenerative thermal oxidizers is expected to require an additional 180 million kilowatt hours per year and an additional 4.9 billion standard cubic feet per year of natural gas.

E. Can We Achieve the Goals of the Proposed Rule in a Less Costly Manner?

We have made every effort in developing this proposal to minimize the cost to the regulated community and allow maximum flexibility in compliance options consistent with our statutory obligations. We recognize, however, that the proposal may still require some facilities to take costly steps to further control emissions even though those emissions may not result in exposures which could pose an excess individual lifetime cancer risk greater than 1 in 1 million or exceed thresholds determined to provide an ample margin of safety for protecting public health and the environment from the effects of HAP. We are, therefore, specifically soliciting comment on whether there are further ways to structure the proposed rule to focus on the facilities which pose significant risks and avoid the imposition of high costs on facilities that pose little risk to public health and the environment.

During the rulemaking process on a separate proposed NESHAP, representatives of the plywood and composite wood products industry provided EPA with descriptions of three approaches that they believed could be used to implement more cost-effective reductions in risk. These approaches could be effective in focusing regulatory controls on facilities that pose significant risks and avoiding the

imposition of high costs on facilities that pose little risk to public health or the environment, and we are seeking public comment on the utility of each of these approaches with respect to this rule. The docket for today's proposed rule contains “white papers” prepared by the plywood and composite wood products industry that outline their proposed approaches (
see
docket number A-2001-22).

One of the approaches, an applicability cutoff for threshold pollutants, would be implemented under the authority of CAA section 112(d)(4); the second approach, subcategorization and delisting, would be implemented under the authority of CAA section 112(c)(1) and (c)(9); and the third approach would involve the use of a concentration-based applicability threshold. We are seeking comment on whether these approaches are legally justified and, if so, we ask for information that could be used to support such approaches.

The MACT program outlined in CAA section 112(d) is intended to reduce emissions of HAP through the application of MACT to major sources of toxic air pollutants. Section 112(c)(9) is intended to allow EPA to avoid setting MACT standards for categories or subcategories of sources that pose less than a specified level of risk to public health and the environment. The EPA requests comment on whether the proposals described here appropriately rely on these provisions of CAA section 112. The two health-based approaches focus on assessing inhalation exposures or accounting for adverse environmental impacts. In addition to the specific requests for comment noted in this section, we are also interested in any information or comment concerning technical limitations, environmental and cost impacts, compliance assurance, legal rationale, and implementation relevant to the identified approaches. We also request comment on appropriate practicable and verifiable methods to ensure that sources' emissions remain below levels that protect public health and the environment. We will evaluate all comments before determining whether to include an approach in the final rule.

1. Industry HAP emissions and potential health effects

For the automobile and light-duty truck surface coating source category, seven HAP account for over 95 percent of the total HAP emitted. Those seven HAP are toluene, xylene, glycol ethers (including ethylene glycol monobutyl ether (EGBE)), MEK, MIBK, ethylbenzene, and methanol. Additional HAP which may be emitted by some automobile and light-duty truck surface coating operations are: Ethylene glycol, hexane, formaldehyde, chromium compounds, diisocyanates, manganese compounds, methyl methacrylate, methylene chloride, and nickel compounds.

Of the seven HAP emitted in the largest quantities by this source category, all can cause toxic effects following sufficient exposure. The potential toxic effects of these seven HAP include effects to the central nervous system, such as fatigue, nausea, tremors, and loss of motor coordination; adverse effects on the liver, kidneys, and blood; respiratory effects; and developmental effects. In addition, one of the seven predominant HAP, EGBE, is a possible carcinogen, although information on this compound is not currently sufficient to allow us to quantify its potency.

In accordance with CAA section 112(k), EPA developed a list of 33 HAP which present the greatest threat to public health in the largest number of urban areas. None of the predominant seven HAP is included on this list for EPA's Urban Air Toxics Program, although three of the other emitted HAP (formaldehyde, manganese compounds, and nickel compounds) appear on the list. In November 1998, EPA published “A Multimedia Strategy for Priority Persistent, Bioaccumulative, and Toxic (PBT) Pollutants.” None of the predominant seven HAP emitted by automobile and light-duty truck surface coating operations appears on the published list of compounds referred to in EPA's PBT strategy.

To estimate the potential baseline risks posed by the source category and the potential impact of applicability cutoffs, EPA performed a “rough” risk assessment for 56 of the approximately 60 facilities in the source category by using a model plant placed at the actual location of each plant and simulating impacts using air emissions data from the 1999 EPA Toxics Release Inventory (TRI). In addition to the seven predominant HAP, the following additional HAP were included in this rough risk assessment because they were reported in TRI as being emitted by facilities in the source category: ethylene glycol, hexane, formaldehyde, diisocyanates, manganese compounds, nickel compounds, and benzene. The benzene emissions and some of the nickel emissions are from non-surface coating activities which are not part of the source category. Of the HAP reported in TRI which are emitted from automobile and light-duty truck surface coating operations, three (formaldehyde, nickel compounds, and EGBE) are carcinogens that, at present, are not considered to have thresholds for cancer effects. Ethylene glycol monobutyl ether, however, may be a threshold carcinogen, as suggested by some recent evidence from animal studies, though EPA, at present, considers it to be a non-threshold carcinogen without sufficient information to quantify its cancer potency. Likewise, formaldehyde is a potential threshold carcinogen, and EPA is currently revising the dose-response assessment for formaldehyde. Most facilities in this source category emit some small quantity of formaldehyde. In the 1999 TRI, however, only two facilities in this source category reported formaldehyde emissions. No other facilities exceeded the TRI reporting threshold for formaldehyde in 1999.

The baseline cancer risk and subsequent cancer risk reductions were estimated to be minimal for this source category. Of the three carcinogens included in the assessment, emissions reductions attributable to the proposed standards could be estimated for only EGBE. However, since EGBE risks cannot currently be quantified, the cancer risk reductions associated with the proposed rule are estimated by this rough assessment to be minimal. However, noncancer risks are projected to be significantly reduced by the proposed rule. (Details of this assessment are available in the docket.)

2. Applicability Cutoffs for Threshold Pollutants Under CAA Section 112(d)(4)

The first approach is an “applicability cutoff” for threshold pollutants that is based on EPA's authority under CAA section 112(d)(4) to establish standards for HAP which are “threshold pollutants.” A “threshold pollutant” is one for which there is a concentration or dose below which adverse effects are not expected to occur over a lifetime of exposure. For such pollutants, section 112(d)(4) allows EPA to consider the threshold level, with an ample margin of safety, when establishing emission standards. Specifically, section 112(d)(4) allows EPA to establish emission standards that are not based upon the MACT specified under section 112(d)(2) for pollutants for which a health threshold has been established. Such standards may be less stringent than MACT. Historically, EPA has interpreted section 112(d)(4) to allow categories of sources that emit only threshold pollutants to avoid further regulation if those emissions result in ambient levels that do not exceed the

threshold, with an ample margin of safety.
1

1

See
63 18754, 18765-66 (April 15, 1998) (Pulp and Paper Combustion Sources Proposed NESHAP).

A different interpretation would allow us to exempt individual facilities within a source category that meet the section 112(d)(4) requirements. There are three potential scenarios under this interpretation of the section 112(d)(4) provision. One scenario would allow an exemption for individual facilities that emit only threshold pollutants and can demonstrate that their emissions of threshold pollutants would not result in air concentrations above the threshold levels, with an ample margin of safety, even if the category is otherwise subject to MACT. A second scenario would allow the section 112(d)(4) provision to be applied to both threshold and non-threshold pollutants, using the 1 in 1 million cancer risk level for decisionmaking for non-threshold pollutants.

A third scenario would allow a section 112(d)(4) exemption at a facility that emits both threshold and non-threshold pollutants. For those emission points where only threshold pollutants are emitted and where emissions of the threshold pollutants would not result in air concentrations above the threshold levels, with an ample margin of safety, those emission points could be exempt from the MACT standards. The MACT standards would still apply to non-threshold emissions from other emission points at the source. For this third scenario, emission points that emit a combination of threshold and non-threshold pollutants that are co-controlled by MACT would still be subject to the MACT level of control. However, any threshold HAP eligible for exemption under section 112(d)(4) that are controlled by control devices different from those controlling non-threshold HAP would be able to use the exemption, and the facility would still be subject to the sections of the standards that control non-threshold pollutants or that control both threshold and non-threshold pollutants.

Estimation of hazard quotients and hazard indices.
Under the section 112(d)(4) approach, EPA would have to determine that emissions of each of the threshold pollutants emitted by automobile and light-duty truck surface coating operations at the facility do not result in exposures which exceed the threshold levels, with an ample margin of safety.

The common approach for evaluating the potential hazard of a threshold air pollutant is to calculate a “hazard quotient” by dividing the pollutant's inhalation exposure concentration (often assumed to be equivalent to its estimated concentration in air at a location where people could be exposed) by the pollutant's inhalation Reference Concentration (RfC). An RfC is an estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure that, over a lifetime, likely would not result in the occurrence of adverse health effects in humans, including sensitive individuals.

The EPA typically establishes an RfC by applying uncertainty factors to the critical toxic effect derived from the lowest-or no-observed-adverse-effect level of a pollutant
2

. A hazard quotient less than one means that the exposure concentration of the pollutant is less than the RfC and, therefore, presumed to be without appreciable risk of adverse health effects. A hazard quotient greater than one means that the exposure concentration of the pollutant is greater than the RfC. Further, EPA guidance for assessing exposures to mixtures of threshold pollutants recommends calculating a hazard index (HI) by summing the individual hazard quotients for those pollutants in the mixture that affect the same target organ or system by the same mechanism
3

. The HI values would be interpreted similarly to hazard quotients; values below one would generally be considered to be without appreciable risk of adverse health effects, and values above one would generally be cause for concern.

2
“Methods for Derivation of Inhalation reference Concentrations and Applications of Inhalation Dosimetry.” EPA-600/8-90-066F, Office of Research and Development, USEPA, October 1994.

3
“Supplementary Guidance for Conducting Health Risk Assessment of Chemical Mixtures. Risk Assessment Forum Technical Panel,” EPA/630/R-00/002. USEPA, August 2000.
http://www.epa.gov/nceawww1/pdfs/chem_mix/chem_mix_08_2001.pdf.

For the determinations discussed herein, EPA would generally plan to use RfC values contained in EPA's toxicology database, the Integrated Risk Information System (IRIS). When a pollutant does not have an approved RfC in IRIS, or when a pollutant is a carcinogen, EPA would have to determine whether a threshold exists based upon the availability of specific data on the pollutant's mode or mechanism of action, potentially using a health threshold value from an alternative source, such as the Agency for Toxic Substances and Disease Registry (ATSDR) or the California Environmental Protection Agency (CalEPA). Table 4 provides RfC, as well as unit risk estimates, for the HAP emitted by automobile and light-duty truck surface coating operations. A unit risk estimate is defined as the upper-bound excess lifetime cancer risk estimated to result from continuous exposure to an agent at a concentration of 1 ug/m
3
in the air.

Table 4.—Dose-Response Assessment Values for HAP Reported Emitted by the Automobile and Light-Duty Truck Surface Coating Source Category

Chemical name
CAS No.

Reference concentration
a
(mg/m
3
)

Unit risk estimate
b

(1/(ug/m
3
))

Chromium (VI) compounds
18540-29-9
1.0E-04 (IRIS)
1.2E-02 (IRIS)

Chromium (VI) trioxide, chromic acid mist
11115-74-5
8.0E-06 (IRIS)

Ethyl benzene
100-41-4
1.0E+00 (IRIS)

Ethylene glycol
107-21-1
4.0E-01 (CAL)

Formaldehyde
50-00-0
9.8E-03 (ATSDR)
1.3E-05 (IRIS)

Diethylene glycol monobutyl ether
112-34-5
2.0E-02 (HEAST)

Ethylene glycol monobutyl ether
111-76-2
1.3E+01 (IRIS)

Hexamethylene-1, 6-diisocyanate
822-06-0
1.0E-05 (IRIS)

n-Hexane
110-54-3
2.0E-01 (IRIS)

Manganese compounds
7439-96-5
5.0E-05 (IRIS)

Methanol
67-56-1
4.0E+00 (CAL)

Methyl ethyl ketone
78-93-3
1.0E+00 (IRIS)

Methyl isobutyl ketone
108-10-1
8.0E-02 (HEAST)

Methyl methacrylate
80-62-6
7.0E-01 (IRIS)

Methylene chloride
75-09-2
1.0E+00 (ATSDR)
4.7E-07 (IRIS)

Methylene diphenyl diisocyanate
101-68-8
6.0E-04 (IRIS)

Nickel compounds
7440-02-0
2.0E-04 (ATSDR)

Nickel oxide
1313-99-1
1.0E-04 (CAL)

Toluene
108-88-3
4.0E-01 (IRIS)

2,4/2,6-Toluene diisocyanate mixture (TDI)
26471-62-5
7.0E-05 (IRIS)
1.1E-05 (CAL)

Xylenes (mixed)
1330-20-7
4.3E-01 (ATSDR)

a
Reference Concentration: An estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups which include children, asthmatics, and the elderly) that is likely to be without an appreciable risk of deleterious effects during a lifetime. It can be derived from various types of human or animal data, with uncertainty factors generally applied to reflect limitations of the data used.

b
Unit Risk Estimate: The upper-bound excess lifetime cancer risk estimated to result from continuous exposure to an agent at a concentration of 1 ug/m
3
in air. The interpretation of the Unit Risk Estimate would be as follows: if the Unit Risk Estimate = 1.5 × 10
−6
per ug/m
3
, 1.5 excess tumors are expected to develop per 1,000,000 people if exposed daily for a lifetime to 1 ug of the chemical in 1 cubic meter of air. Unit Risk Estimates are considered upper bound estimates, meaning they represent a plausible upper limit to the true value. (Note that this is usually not a true statistical confidence limit.) The true risk is likely to be less, but could be greater.

Sources:
IRIS = EPA Integrated Risk Information System
(http://www.epa.gov/iris/subst/index.html)
ATSDR = U.S. Agency for Toxic Substances and Disease Registry
(http://www.atsdr.cdc.gov/mrls.html)
CAL = California Office of Environmental Health Hazard Assessment
(http://www.oehha.ca.gov/air/hot_spots/index.html)
HEAST = EPA Health Effects Assessment Summary Tables (#PB(=97-921199, July 1997).

To establish an applicability cutoff under section 112(d)(4), EPA would need to define ambient air exposure concentration limits for any threshold pollutants involved. There are several factors to consider when establishing such concentrations. First, we would need to ensure that the concentrations that would be established would protect public health with an ample margin of safety. As discussed above, the approach EPA commonly uses when evaluating the potential hazard of a threshold air pollutant is to calculate the pollutant's hazard quotient, which is the exposure concentration divided by the RfC.

The EPA's “Supplementary Guidance for Conducting Health Risk Assessment of Chemical Mixtures” suggests that the noncancer health effects associated with a mixture of pollutants ideally are assessed by considering the pollutants' common mechanisms of toxicity.
4

The guidance also suggests that when exposures to mixtures of pollutants are being evaluated, the risk assessor may calculate a HI. The recommended method is to calculate multiple hazard indices for each exposure route of interest and for a single specific toxic effect or toxicity to a single target organ. The default approach recommended by the guidance is to sum the hazard quotients for those pollutants that induce the same toxic effect or affect the same target organ. A mixture is then assessed by several HI, each representing one toxic effect or target organ. The guidance notes that the pollutants included in the HI calculation are any pollutants that show the effect being assessed, regardless of the critical effect upon which the RfC is based. The guidance cautions that if the target organ or toxic effect for which the HI is calculated is different from the RfC's critical effect, then the RfC for that chemical will be an overestimate, that is, the resultant HI potentially may be overprotective. Conversely, since the calculation of a HI does not account for the fact that the potency of a mixture of HAP can be more potent than the sum of the individual HAP potencies, a HI may potentially be underprotective in some situations.

4
Ibid.

Options for establishing a HI limit.
One consideration in establishing a HI limit is whether the analysis considers the total ambient air concentrations of all the emitted HAP to which the public is exposed.
5

There are several options for establishing a HI limit for the section 112(d)(4) analysis that reflect, to varying degrees, public exposure.

5
Senate Debate on Conference Report (October 27, 1990), reprinted in “A Legislative History of the Clean Air Act Amendments of 1990,” Comm. Print S. Prt. 103-38 (1993) (“Legis. Hist.”) at 868.

One option is to allow the HI posed by all threshold HAP emitted from automobile and light-duty truck surface coating operations at the facility to be no greater than one. This approach is protective if no additional threshold HAP exposures would be anticipated from other sources at, or in the vicinity of, the facility or through other routes of exposure (
e.g.
, through dermal absorption).

A second option is to adopt a “default percentage” approach, whereby the HI limit of the HAP emitted by the facility is set at some percentage or fraction of one (
e.g.
, 20 percent or 0.2). This approach recognizes the fact that the facility in question is only one of many sources of threshold HAP to which people are typically exposed every day. Because noncancer risk assessment is predicated on total exposure or dose, and because risk assessments focus only on an individual source, establishing a HI limit of 0.2 would account for an assumption that 20 percent of an individual's total exposure is from that individual source. For the purposes of this discussion, we will call all sources of HAP, other than operations within the source category at the facility in question, “background” sources. If the affected source is allowed to emit HAP such that its own impacts could result in HI values of one, total exposures to threshold HAP in the vicinity of the facility could be substantially greater than one due to background sources, and this would not be protective of public health since only HI values below one are considered to be without appreciable risk of adverse health effects. Thus, setting the HI limit for the facility at some default percentage of one will provide a buffer which would help to ensure that total exposures to threshold HAP near the facility (
i.e.
, in combination with exposures due to background sources) will generally not exceed one and can generally be considered to be without appreciable risk of adverse health effects.

The EPA requests comment on using the “d

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A02-31420. Public record. Not legal advice.