Control Techniques Guidelines for Automobile
and Light-Duty Truck Assembly Coatings
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EPA-453/R-08-006
September 2008
Control Techniques Guidelines for Automobile and
Light-Duty Truck Assembly Coatings
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Sector Policies and Programs Division
Research Triangle Park, NC
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TABLE OF CONTENTS
I. Introduction 1
II. Background and Overview 2
III. Applicability 3
IV. Process Description and Sources of VOC Emissions 6
A. Process Description 7
1. Surface Preparation 7
2. Priming Operations 7
3. Topcoat Operations .8
4. Final Repair Operations 8
5. Cleaning Activities 8
B. Sources of VOC Emissions 9
1. Coatings 9
2. Cleaning Materials 10
V. Available Controls and Regulatory Approaches 11
A. Available Controls for VOC Emissions from Coatings and Drying 11
1. Pollution Prevention Measures 11
2. Emission Capture and Add-on Control Systems 12
B. Available Controls for VOC Emissions from Cleaning Materials 14
1. Product Substitution/Reformulation 14
2. Work Practice Procedures 14
C. Existing Federal, State, and Local Recommendations or Regulations 14
1. The 1977 CTG 15
2. The 1980 NSPS 16
3. The 2004 NESHAP 17
4. Existing State and Local VOC Requirements 18
VI. Recommended Control Techniques 18
A. Coatings 18
B. Work Practices for Coating-Related Activities and Cleaning Materials ..22
VII. Emission Reductions and Cost Effectiveness of Recommended Control Options 23
VIII. References 24
LIST OF APPENDICES
Appendix A: Definitions
Appendix B: 1977 CTG for Surface Coating of Cans, Coils, Paper, Fabrics, Automobiles,
and Light-Duty Trucks
Appendix C: Summary of Selected State Regulations for Automobile and Light-Duty Truck
Assembly Coatings (including Bay Area AQMD)
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I. Introduction
Clean Air Act (CAA) section 172(c)(l) provides that stale implementation plans (SIPs)
for nonattainment areas must include "reasonably available control measures" (RACM),
including "reasonably available control technology" (RACT), for sources of emissions. Section
182(b)(2)(A) provides that for certain nonattainment areas, States must revise their SIPs to
include RACT for each category of volatile organic compound (VOC) sources covered by a
control techniques guidelines (CTG) document issued between November 15, 1990 and the
date of attainment.
The United States Environmental Protection Agency (EPA) defines RACT as "the
lowest emission limitation that a particular source is capable of meeting by the application of
control technology that is reasonably available considering technological and economic
feasibility." 44 FR 53761 (Sept. 17, 1979). In subsequent Federal Register notices, EPA has
addressed how States can meet the RACT requirements of the CAA.
Clean Air Act section 183(e) directs EPA to list for regulation those categories of
products that account for at least 80 percent of the VOC emissions, on a reactivity-adjusted
basis, from consumer and commercial products in areas that violate the NAAQS for ozone (i.e.,
ozone nonattainment areas). EPA issued the list on March 23, 1995, and has revised the list
periodically. See 60 FR 15264 (March 23, 1995); see also 71 FR 28320 (May 16, 2006), 70 FR
69759 (Nov. 17, 2005); 64 FR 13422 (Mar. 18, 1999). Auto and light-duty truck assembly
coatings are included on the current section 183(e) list.
This CTG is intended to provide State and local air pollution control authorities
information that should assist them in determining RACT for VOCs from automobile and light-
duty truck assembly coatings. In developing this CTG, EPA, among other things, evaluated the
sources of VOC emissions from the automobile and light-duty truck assembly coating industry
and the available control approaches for addressing these emissions, including the costs of such
approaches. Based on available information and data, EPA provides recommendations for RACT
for automobile and light-duty truck assembly coating.
States can use the recommendations in this CTG to inform their own determination as to
what constitutes RACT for VOCs for automobile and light-duty truck assembly coatings in their
particular nonattainment areas. There are several hazardous air pollutants (HAPs) that are also
VOCs. The information contained in this document is provided only as guidance. This guidance
does not change, or substitute for, requirements specified in applicable sections of the CAA or
EPA's regulations; nor is it a regulation itself. This document does not impose any legally
binding requirements on any entity. It provides only recommendations for State and local air
pollution control agencies to consider in determining RACT. State and local pollution control
agencies are free to implement other technically-sound approaches that are consistent with the
CAA and EPA's implementing regulations.
The recommendations contained in this CTG are based on data and information currently
available to EPA. These general recommendations may not apply to a particular situation based
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upon the circumstances of a specific source. Regardless of whether a State chooses to implement
the recommendations contained herein through State rules, or to issue State rules that adopt
different approaches for RACT for VOCs from automobile and light-duty truck assembly
coatings, States must submit their RACT rules to EPA for review and approval as part of the SIP
process. EPA will evaluate the rules and determine, through notice and comment rulemaking in
the SIP approval process, whether the submitted rules meet the RACT requirements of the CAA
and EPA's regulations. To the extent a State adopts any of the recommendations in this
guidance into its State RACT rules, interested parties can raise questions and objections about
the substance of this guidance and the appropriateness of the application of this guidance to a
particular situation during the development of the State rules and EPA's SIP approval process.
Clean Air Act section 182(b)(2) requires that a CTG issued between November 15, 1990,
and the date of attainment include the date by which States subject to section 182(b) must submit
SIP revisions in response to the CTG. Accordingly, EPA is providing in this CTG a one-year
period for the required submittal. Pursuant to section 182(b)(2), States required to submit rules
consistent with section 182(b) must submit their SIP revisions within one year of the date of
issuance of the final CTG for automobile and light-duty truck assembly coatings.
II. Background and Overview
There have been three federal actions that affect automobile and light-duty truck
assembly coating operations. In May 1977, EPA issued a CTG document (1977 CTG) for
controlling VOC emissions from surface coating of automobiles and light-duty trucks.1 In
December 1980, EPA promulgated the new source performance standards (NSPS) for
automobile and light-duty truck assembly coating operations (1980 NSPS).2 In April 2004,
EPA promulgated the National Emission Standards for Hazardous Air Pollutants: Surface
Coating of Automobiles and Light-Duty Trucks (2004 NESHAP).3
The 1977 CTG, the 1980 NSPS and the 2004 NESHAP provide a thorough discussion of
the automobile and light-duty truck assembly coating industry, the nature of VOC emissions (or
in the case of the 2004 NESHAP, organic HAP emissions) from this industry, available control
technologies for addressing such emissions, the costs of available control options, and other items.
The 1977 CTG recommends and the 1980 NSPS establishes VOC emissions limits, whereas the
2004 NESHAP establishes organic HAP emissions limits and does not address non-HAP VOC.
At least 14 States and one California air pollution control district have specific
regulations that control VOC emissions from automobile and light-duty truck assembly coating.
A discussion of the applicability and control options found in the federal actions and State and
local rules is presented in Section V of this document.
EPA developed the recommended approaches contained in this document after
reviewing the 1977 CTG, the 1980 NSPS, the 2004 NESHAP, existing State and local VOC
emission reduction approaches, and data provided by the industry in 2008.
The remainder of this document is divided into six sections. Section III describes the
scope of sources to which the control recommendations in this CTG could apply. Section IV
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describes the automobile and light-duty truck assembly coating industry, including the types of
automobile and light-duty trucks, the coating materials and the coating processes, and identifies
the sources of VOC emissions from those processes. Section V describes the available control
approaches for addressing VOC emissions from this product category and summarizes Federal,
State and local approaches for addressing such emissions. Section VI provides our
recommendations for RACT for automobile and light-duty truck assembly coating. Section VII
discusses the cost-effectiveness of the recommended control approaches. Section VIII contains a
list of references.
III. Applicability
This section addresses EPA's recommendations as to the scope of entities to which the
RACT recommendations in this CTG should apply. As explained above, this document is a
guidance document and provides information for States to consider in determining RACT.
When State and local pollution control agencies develop RACT rules, they may elect to adopt
control approaches that differ from those described in this document and/or promulgate
applicability criteria that differ from those recommended here.
This CTG provides control recommendations for reducing VOC emissions stemming from
the use of coatings in automobile and light-duty truck3 assembly coating operations. We
recommend that the control approaches discussed in section VI of this CTG apply to each
automobile and light-duty truck assembly coating operation at a facility where the total actual
VOC emissions from all automobile and light-duty truck assembly coating operations, including
related cleaning activities, at that facility are equal to or exceed 6.8 kg/day (15 Ib/day), before
consideration of controls. We do not recommend these control approaches for facilities that emit
below this level because of the very small VOC emission reductions that can be achieved. The
recommended threshold level is equivalent to the evaporation of approximately 2 gallons of
solvent per day. Such a level is considered to be an incidental level of solvent usage that could
be expected even in facilities that use very low-VOC content coatings. Furthermore, based on
the April 2004 ozone nonattainment designations, we estimate that all of the automobile and
light-duty truck surface coating facilities are located in ozone nonattainment areas and emit 6.8
kg/day (15 Ib/day) or more. Therefore, we expect that our recommendations in this CTG would
apply to all automobile and light-duty truck surface coating facilities in ozone nonattainment
areas.
The automobile and light-duty truck assembly coatings product category under section
183(e) of the CAA includes the primary coatings'3 that are applied to (1) new automobile or new
light-duty truck bodies, or body parts for new automobiles or new light-duty trucks, and (2) other
parts that are coated along with these bodies or body parts. The category also includes additional
coatings applied during the vehicle assembly process0. Automobile and light-duty truck assembly
a Automobile means a motor vehicle designed to carry up to eight passengers, excluding vans, sport utility vehicles,
and motor vehicles designed primarily to transport light loads of property. Light-duty truck means vans, sport utility
vehicles, and motor vehicles designed primarily to transport light loads of property with gross vehicle weight rating
of 8,500 Ibs or less.
b The primary coatings are electrodeposition primer, primer-surfacer, topcoat, and final repair. These coatings are
defined in Appendix B.
c Coatings applied during the vehicle assembly process include glass bonding primer, adhesives, cavity wax, sealer,
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coatings most commonly are applied at automobile or light-duty truck assembly plants.
However, this 183(e) category also includes coatings used in facilities that perform these coating
operations on a contractual basis. This category does not include coatings used at plastic or
composites molding facilities as described in the Surface Coating of Automobiles and Light-
Duty Trucks NESHAP (40 CFR part 63, subpart IIII). Please see section IV of this CTG for
further description of the auto and light-duty truck assembly coatings category under section
183(e)oftheCAA.
In addition to the coating applications described above, automobile and light-duty truck
assembly coating facilities may have separate coating lines on which coatings are applied to
other parts intended for use in new automobiles or new light-duty trucks (e.g., application of
spray primer, color and clear coat to fascia or bumpers) or to aftermarket repair or replacement
parts for automobiles or light-duty trucks. The separate coating of these other parts and
aftermarket or replacement parts is included in the Miscellaneous Metal Products and Plastic
Parts Coatings categories under section 183(e) and covered in the CTG for those categories.
However, States may want to evaluate, given the facts and circumstances of the automobile and
light-duty truck assembly coating facilities in their states, whether it is appropriate to give these
facilities the option of having their separate coating of other parts and aftermarket repair or
replacement parts, as described above, covered under the State miscellaneous metal and plastic
parts coatings RACT rule or the State automobile and light-duty truck assembly coating RACT
rule.
Furthermore, we recommend that states consider structuring their RACT rules to provide
facilities that coat bodies and/or body parts for new heavier vehicles with the option of meeting
either the state RACT requirements for the automobile and light-duty truck coating category or
the state RACT requirements for the miscellaneous metal products or plastic parts coatings
categories. Heavier vehicle coatings are included in the Miscellaneous Metal Products and
Plastic Parts Coatings categories under section 183(e) and are therefore covered in the CTG for
Miscellaneous Metal and Plastic Parts Coatings. We note, however, that some automobile and
light-duty truck assembly coating facilities also coat new heavier vehicle bodies or body parts for
new heavier vehicles. The new heavier vehicle bodies or body parts for new heavier vehicles
may be coated using the same equipment and materials that are used to coat new automobile and
light-duty truck bodies or body parts for new automobiles and light-duty trucks. The permit
requirements for the heavier vehicle portion of these combined use paint shops are often
structured in the same way as permit requirements for automobile and light-duty truck paint
shops. Also, some facilities that coat only new heavier vehicle bodies or body parts for new
heavier vehicles have paint shops that are designed and operated in the same manner as paint
shops that are used to coat new automobile and light-duty truck bodies and body parts for new
automobiles and light-duty trucks. The permit requirements for these heavier vehicle paint shops
are often structured in the same way as permit requirements for automobile and light-duty truck
paint shops.
deadener, gasket/gasket sealing material, underbody coating, trunk interior coating, bedliner, weatherstrip adhesive,
and lubricating waxes/compounds. These coatings are defined in Appendix B.
d Heavier vehicles includes all vehicles that meet the definition .of the term "other motor vehicles", as defined at 40
CFR § 63.3176 (the NESHAP for Surface Coating of Automobiles and Light-Duty Trucks).
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In light of the above, providing facilities that coat bodies and/or body parts for new
heavier vehicles with the option of meeting the state RACT requirements for the automobile and
light-duty truck coating category in lieu of the requirements for Miscellaneous Metal Products or
Plastic Parts categories will provide for the most consistency with existing permit requirements
and simplify compliance demonstration requirements for these facilities. Furthermore, in light of
the stringency of our recommended control measures in this CTG, we believe that facilities that
choose this alternative will achieve at least equivalent, if not greater, control of VOC emissions.
For the reasons stated above, we recommend that state RACT rules provide facilities that coat
bodies and/or body parts for new heavier vehicles the option of meeting either the state RACT
requirements for miscellaneous metals and plastic parts coatings or the state RACT requirements
for auto and light-duty truck coatings.
Like automobile and light-duty truck assembly coating facilities, facilities that coat
bodies and/or body parts for new heavier vehicles may have separate coating lines on which
coatings are applied to other parts intended for use in new heavier vehicles, or to aftermarket
repair or replacement parts for heavier vehicles. The separate coating of these other parts and
aftermarket or replacement parts is included in the Miscellaneous Metal Products and Plastic
Parts Coatings categories under section 183(e) and covered in the CTG for that category. As
mentioned above, we recommend that State RACT rules provide facilities that coat bodies and/or
body parts for new heavier vehicles with the option of meeting either the state RACT
requirements for automobile and light-duty truck coatings or the state RACT requirements for
miscellaneous metal products or plastic parts coatings. States that choose to provide this option
may also want to evaluate, given the facts and circumstances of the heavier vehicle coating
facilities at issue in their states, whether it is appropriate to give these facilities the option of
having their separate coating of other parts and aftermarket repair or replacement parts, as
described above, covered under the State miscellaneous metal and plastic parts coatings RACT
rule or the State automobile and light-duty truck assembly coating RACT rule.
For purposes of determining whether a facility meets our recommended applicability
threshold, aggregate emissions, before consideration of control, from all automobile and light-
duty truck assembly coating operations (including related cleaning activities) at a given facility
are included.
In developing RACT rules, State and local agencies should consider carefully the facts
and circumstances of the affected sources in their States. As noted above, States can adopt the
above recommended 6.8 kg/day (15 Ib/day) actual VOC emissions or an equivalent applicability
threshold, or they can develop other applicability criteria that they determine are appropriate
considering the facts and circumstances of the sources in their particular nonattainment areas.
EPA will review the State RACT rules in the context of the SIP revision process.
There are currently 52 automobile and light-duty truck assembly facilities that engage in
surface coating operations in the United States. The highest concentration of these facilities are
in Michigan, Illinois, Indiana, and Ohio.
For the development of this CTG, we considered VOC emissions data from information
gathered during the development of the 2004 NESHAP. We also considered VOC emissions data
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submitted in 2008 by the Alliance of Automobile Manufacturers member companies and non-
member companies.
The 2004 NESHAP survey collected information for 61 facilities in operation in 1996.
Although information regarding HAP emissions was the main focus of the NESHAP survey,
information regarding VOC emissions was also submitted.
The Alliance for Automobile Manufacturers member companies and non-member
companies submitted VOC emissions data for calendar years 2006 and 2007. Emissions
information from surface coating operations during automobile and light-duty truck
manufacturing was provided on a daily minimum, daily maximum, and daily and monthly
average basis. Information was provided for 52 facilities located in the United States.
The 2002 National Emissions Inventory (NEI) contains information for 48 of these 52
facilities. (The other four facilities were not yet operating in 2002.) These 48 facilities reported
actual VOC emissions totaling approximately 27,500 tons in 2002.
IV. Process Description and Sources of VOC Emissions
The auto and light-duty truck assembly coatings product category under section 183(e)
of the CAA includes the coatings that are applied to new automobile or new light-duty truck
bodies, or body parts for new automobiles or new light-duty trucks. The large majority of these
coatings are specifically formulated, marketed and sold for this end use and are applied at
automobile or light-duty truck assembly plants. However, this 183(e) category also includes
coatings used in facilities that perform these coating operations on a contractual basis. This
category does not include coatings used at plastic or composites molding facilities as described
in the Surface Coating of Automobiles and Light-Duty Trucks NESHAP (40 CFR part 63,
subpart IIII).
Automobile and light-duty truck coatings enhance a vehicle's durability and appearance.
Some of the coating system characteristics that automobile and light-duty truck manufacturers
test for include adhesion, water resistance, humidity resistance, salt spray resistance, color, gloss,
acid etch resistance, and stone chip resistance. The primary coatings used are electrodeposition
primer, primer-surfacer (including anti-chip coatings), topcoat (basecoat and clearcoat) and final
repair. Glass bonding primer, adhesives, cavity wax, sealer, deadener, gasket/gasket sealing
material, underbody coating, trunk interior coating, bedliner, weatherstrip adhesive, and
lubricating waxes/compounds also are used at automobile or light-duty assembly coating
facilities. These coatings are included as "automobile and light-duty truck" materials in the
automobile and light-duty truck assembly coatings product category and are addressed in this
CTG.
Glass bonding primer, adhesives, cavity wax, sealer, deadener, gasket/gasket sealing
material, underbody coating, trunk interior coating, bedliner, weatherstrip adhesive, and
lubricating waxes/compounds also are used in the production of vehicles other than automobiles
or light-duty trucks, and may be used in activities related to the production of new automobiles
or new light-duty trucks or aftermarket parts for automobiles and light-duty trucks at facilities
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that are not automobile or light-duty truck assembly coatings facilities. These materials are
included as "motor vehicle" materials in the miscellaneous metal products and plastic parts
coatings categories or the miscellaneous industrial adhesives category, and are addressed in the
CTGs for those categories. The recommended limits for the "motor vehicle" materials in the
CTGs for those categories are the same as the recommended limits for "automobile and light-
duty truck" materials in this CTG. Definitions and VOC control recommendations for the
following types of materials are included in the miscellaneous metal and plastic coatings CTG:
motor vehicle cavity wax, motor vehicle sealer, motor vehicle deadener, motor vehicle trunk
interior coating, motor vehicle bedliner, motor vehicle gasket/gasket sealing material, motor
vehicle underbody coating, and motor vehicle lubricating wax/compound. Definitions and VOC
control recommendations for the following types of materials are included in the miscellaneous
industrial adhesives CTG: motor vehicle glass bonding primer, motor vehicle adhesive, and
motor vehicle weatherstrip adhesive.
Aerosol coatings are not included in the automobile and light-duty truck assembly
coating category. Aerosol coatings are a separate category under section 183(e) and are
addressed by the national VOC rule for aerosol coatings.
A. Process Description
The coating process for automobiles and light-duty trucks consists of the following
operations: (1) surface preparation, (2) priming operations, (3) topcoat operations, (4) final
repair operations, and (5) cleaning activities. In addition, cleaning activities are performed in
support of the surface coating operation. These operations and activities are further described
below.
1. Surface Preparation
Surface preparation occurs before coatings are applied. During this preparation stage, the
body of an automobile or light-duty truck is assembled, anticorrosion operations are performed,
and any plastic parts to be finished with the body are installed.
2. Priming Operations
After the body has been assembled, anticorrosion operations have been performed, and
plastic parts to be finished with the body are installed, priming operations begin. The purpose of
the priming operations is to further prepare the body for finishing by applying various layers of
coatings designed to protect the metal surface from corrosion and assure good adhesion of
subsequent coatings.
First, an electrodeposited primer (EDP) coating is applied to the body using a method in
which a negatively charged automobile or light-duty truck body is immersed in a positively
charged bath of waterborne electrodeposition primer. The coating particles (resin and pigment)
migrate toward the body and are deposited onto the body surface, creating a strong bond between
the coating and the body to provide a durable coating. Once the coating application deposition is
completed, the body is rinsed in a succession of individual spray and/or immersion rinse stations
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and then dried with an automatic air blow-off. Following the rinsing stage (including the
automatic air blow-off), the deposited coating is cured in an electrodeposition curing oven.
After curing, the body is further water-proofed by sealing spot-welded joints of the body.
After sealing, the body proceeds to the anti-chip booth where anti-chip coatings are applied to
protect the vulnerable areas of the body.
Next, a primer-surfacer coating is applied. The purpose of the primer-surfacer coating is to
provide "filling" or hide minor imperfections in the body, provide additional protection to the
vehicle body, and bolster the appearance of the topcoats. Primer-surfacer coatings are applied by
spray application in a water-wash spray booth. Following application of the primer-surfacer, the
body is baked to cure the film, minimize dirt pickup, and reduce processing time.
3. Topcoat Operations
The next step of the coating process is the spray application of the topcoat, which usually
consists of a basecoat (color) and a clearcoat. The purpose of the clearcoat is to add luster and
durability to the vehicle finish and protect the total coating system against solvents, chemical
agents, water, weather, and other environmental effects.
After the topcoat (i.e., a basecoat and a clearcoat) is applied, the automobile or light-duty
truck body or body parts proceed to a flash-off area, where a certain level of solvent evaporation
occurs. This step is designed to prevent bubble formation during curing in the bake oven. After
flash-off, the automobile and light-duty truck bodies or body parts are then dried/cured in bake
ovens.
4. Final Repair Operations
Final repair means the operations performed and coating(s) applied to completely-
assembled motor vehicles or to parts that are not yet on a completely assembled motor vehicle to
correct damage or imperfections in the coating. The curing of the coatings applied in these
operations is accomplished at a lower temperature than that used for curing primer-surfacer and
topcoat. This lower temperature cure avoids the need to send parts that are not yet on a
completely assembled vehicle through the same type of curing process used for primer-surfacer
and topcoat and is necessary to protect heat sensitive components on completely assembled
motor vehicles.
5. Cleaning Activities
Cleaning materials are used for several purposes, including the removal of coating
residue or other unwanted materials from equipment related to the coating operations such as
spray guns, transfer lines (e.g., tubing or piping), tanks, and the interior of spray booths. These
cleaning materials are typically mixtures of organic solvents.
Work practices are widely used throughout the automobile and light-duty truck
manufacturing industry to reduce VOC emissions from cleaning operations. These measures
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include covering mixing tanks and storing solvents and solvent soaked rags and wipes in closed
containers. Another method is the use of low-VOC content or low vapor pressure cleaning
materials. However, there is insufficient information available to correlate VOC content or
vapor pressure to specific cleaning steps.
B. Sources of VOC Emissions
VOC emissions depend on VOC content, transfer efficiency, and the presence and extent of
VOC control equipment. To lower VOC content, liquid coatings can be reformulated. VOC
contents and emission rates for solvent-borne and waterborne materials also have overlapping
ranges.
The VOC emissions from automobile and light-duty truck assembly coating operations are
primarily a result of evaporation of the VOC contained in the coatings and cleaning materials used
in these operations.e The primary VOC emissions from automobile and light-duty truck assembly
coatings occur during coating application/flash-off and drying/curing of the coatings. The
remaining emissions occur mainly from mixing and/or thinning. The VOC emissions from mixing
and thinning of coatings occur from displacement of VOC-laden air in containers used to mix
coatings containing solvents (thinners) prior to coating application. The displacement of VOC-
laden air can also occur during filling of containers and can be caused by changes in temperature,
changes in barometric pressure, or agitation during mixing. Another source of VOC emissions
from automobile and light-duty truck assembly coating operations is cleaning materials. The
VOC are emitted when solvents evaporate from the cleaning materials during use. In most cases,
VOC emissions from surface preparation, storage, handling, and waste/wastewater operations are
relatively small. The following discussion describes these primary emission sources (coatings
and cleaning materials).
1. Coatings
The VOC emissions from coating application occur when solvent evaporates from the
coating as it is being applied to the vehicle part or body. The transfer efficiency (the ratio of the
amount of coating solids deposited onto the surface of the object to the total amount of coating
solids sprayed while applying the coating to the object) of a coating application method affects
the amount of VOC emitted during coating application. A coating application method that is more
efficient in transferring coatings to the substrate will reduce the volume of coatings (and therefore
solvents) needed per given amount of production, thus reducing VOC emissions.
Until the 1970's, the majority of coatings used in the automobile and light-duty truck
manufacturing industry were conventional solvent-borne coatings, which have high VOC
e In a previous notice, EPA stated that the cleaning operations associated with certain specified section 183(e)
consumer and commercial product categories, including the automobile and light duty truck assembly coatings
category, would not be covered by EPA's 2006 CTG for industrial cleaning solvents (71 FR 44522, 44540, August
4, 2006). In the notice, EPA expressed its intention to address cleaning operations associated with these categories in
the CTGs for these specified categories if the Agency determines that a CTG is appropriate for the respective
categories. Accordingly, this CTG addresses VOC emissions from cleaning operations associated with the
automobile and light-duty truck assembly coatings category.
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content. Due to a combination of regulation at the State and federal level, technology
development and competitive factors, the industry has steadily moved to lower VOC content
coatings. These alternative coatings include powder coatings, waterborne coatings, and higher
solids solvent-borne coatings. The utilization of these alternative coatings in conjunction with
efficient spray application equipment, such as electrostatic spray, is the primary method that is
currently being used at auto and light-duty truck assembly coating operations to reduce VOC
emissions from the coatings. In addition, many facilities control the exhaust from their bake
ovens. Some facilities have also employed partial spray booth controls by venting spray booth
emissions, principally from automated spray zones, through an add-on control device such as an
oxidizer or hybrid (concentrator followed by an oxidizer) control system.
Powder anti-chip and primer-surfacer coatings are used at some automobile and light-
duty truck assembly plants. Powder coating produces minimal amounts of VOC emissions.
Powder coating is applied via powder delivery systems, which in most cases is an electrostatic
spray. Because powder coatings are applied as dried particles, no VOC are released during the
application operation. Depending on the powder formulation, some volatile emissions may
occur when the powder is heated during the curing step. In any event, any volatile emissions
from the heating of powder coatings would generally be much less than the volatile emissions
from the heating of liquid coatings during the curing operations. Powder coating applications are
best suited for long production runs of consistently sized parts without color changes. Powder
anti-chip and primer-surfacer coatings are used at some automobile and light-duty truck
assembly plants.
Waterborne coatings produce less VOC emissions than conventional solvent-borne
coatings primarily because a large portion of the organic solvent carrier (VOC) is replaced with
water. Waterborne electrodeposition primers are used at almost every automobile and light-duty
truck assembly plant. Waterborne primer-surfacer and waterborne basecoat are used at some
automobile and light-duty truck assembly plants. Waterborne primer-surfacer and waterborne
basecoat are applied by a combination of manual and automatic, and electrostatic and non-
electrostatic spray techniques.
Higher solids solvent-borne coatings contain more solids than "conventional" (pre-1980)
solvent-borne coatings. These coatings contain less organic solvent (VOC) per unit volume of
solids than conventional solvent-borne coatings. Thus, a lesser amount of VOC emissions are
released during coating preparation, application, and curing to deliver a given amount of coating
solids. Higher solids primer-surfacer and basecoat are used at some automobile and light-duty
truck assembly plants. Higher solids clearcoat is used at every automobile and light-duty truck
assembly plant. Higher solids primer-surfacer and basecoat are applied by a combination of
manual and automatic, and electrostatic and non-electrostatic spray techniques.
Additional VOC emissions occur in the flash-off area after coatings are applied and in
baking ovens where drying and curing occurs.
2. Cleaning Materials
Cleaning materials are another source of VOC emitted by automobile and light duty
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truck surface coating operations. The VOC are emitted when solvents evaporate from the
cleaning materials during use.
Cleaning materials with low-VOC composite vapor pressure and/or low-VOC content
generate less VOC emissions than materials with higher VOC vapor pressure and/or content.
The VOC composite vapor pressure of a cleaning material is a weighted average of the vapor
pressures of the VOC components of that cleaning material. The vapor pressure of each VOC
component is weighted by the mole fraction of that VOC component in the whole cleaning
material, including non-VOC components such as water or exempt compounds/ Water and
exempt compounds thereby reduce the VOC composite vapor pressure of cleaning materials in
which they are present. Although use of lower vapor pressure cleaning materials may reduce
VOC emissions, insufficient information is available to correlate cleaning material vapor
pressure to specific cleaning steps in the automobile and light-duty truck surface coating
industry. Similarly, cleaning materials with low VOC content would generate less VOC
emissions than materials with high VOC content; however, insufficient information is available
to correlate cleaning material VOC content to specific cleaning steps in this industry.
V. Available Controls and Regulatory Approaches
As previously mentioned, there are two main sources of VOC emissions from automobile
and light-duty truck assembly coating operations: (1) evaporation of VOC from the coatings and
drying; and (2) evaporation of VOC from the cleaning materials. This section summarizes the
available control options for reducing these VOC emissions and existing federal, State, and local
VOC recommendations or requirements that address these emissions.
A. Available Controls for VOC Emissions from Coatings and Drying
There are two general emission control techniques for reducing VOC emissions from
automobile and light-duty truck assembly coatings: pollution prevention measures, and emission
capture and add-on control systems. Pollution prevention is the most prevalent control technique
being used by the automobile and light-duty truck manufacturing industry. Add-on control
systems are also used in this industry. Provided below is a summary of these control techniques.
1. Pollution Prevention Measures
Pollution prevention measures applicable to the automobile and light-duty truck
. manufacturing industry, including product substitution/reformulation, work practice procedures,
and equipment substitution, may be used to decrease VOC emissions from coating application
operations. Lower VOC content coatings, such as powder coatings, higher solids solvent-borne
coatings and waterborne coatings, may be used to reduce VOC emissions by reducing or
eliminating the organic solvent present in the coating. Work practice procedures may also result
in VOC emission reductions during the coating process by reducing coating waste. The use of
efficient coating application equipment reduces VOC emission by increasing the coating transfer
f Exempt compounds are those classified by EPA as having negligible photochemical reactivity as listed in 40 CFR
51.100 (s). Exempt compounds are not considered to be VOC.
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efficiency (i.e., the percentage of coating solids used that is deposited onto the substrate).
Product substitution/Reformulation
One pollution prevention measure is to replace higher-solvent coatings with coatings
containing little or no solvents. As previously discussed, these coatings include waterborne
coatings, higher solids solvent-borne coatings, and electrodeposition coatings. The use of higher
solids and waterborne coatings has increased since the 1970's.
Work Practices
Work practice procedures are physical actions intended to affect emission reductions.
Because work practice procedures are specifically tailored to an industry, they may vary from a
few manual operations to a complex program.
Coating waste is generated during coating material preparation, coating application, and
equipment cleaning. If coating waste is reduced, overall VOC emissions from coating operations
will be reduced because less VOC coating material will be needed for production. Coating waste
may be reduced through work practices by effectively controlling material preparation and using
proper equipment maintenance procedures.
Equipment Substitution
The use of efficient coating application equipment reduces VOC emission by increasing
the coating transfer efficiency (i.e., the percentage of coating solids used that is deposited onto
the substrate). Since the 1970's the spray equipment used to apply automobile and light-duty
truck assembly coatings has become increasingly automated. A significant amount of coating is
applied by reciprocators or robots. At the same time there has also been an increase in the
amount of paint applied electrostatically.
2. Emission Capture and Add-on Control Systems
In addition to pollution prevention measures, VOC emissions from automobile and light-
duty truck assembly coating application operations can be reduced by the use of capture systems,
in conjunction with add-on control systems that either destroy or recover the VOC in the exhaust
streams. As stated previously, many facilities control the exhaust from their bake ovens. Some
facilities have also employed partial spray booth controls by venting spray booth emissions,
principally from automated spray zones, through an add-on control device such as an oxidizer or
hybrid (concentrator followed by an oxidizer) control system. Spray booths typically exhaust a
high volume of air with a low concentration of VOC which can result in a high cost of control.
Capture Systems
Capture systems collect solvent-laden air from process vents (e.g., spray booth, flash-off
or bake oven vents) and direct the captured air to a control device. The majority of VOC
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emissions from automobile and light-duly truck assembly coating occur in the spray booth.
These emissions can be ducted from the spray booth directly to the control device. Similarly,
flash-off area or bake oven exhaust can be ducted directly to the control device. Spray booths
and bake ovens are the principal elements of the capture system.
The design of the capture system can greatly contribute to the overall VOC control
efficiency. An efficient capture system maximizes the capture of emissions and minimizes the
capture of dilution air. Spray booth and bake oven design and air management can reduce the
volume of exhaust air and increase the VOC concentration of the exhaust air which can reduce
the cost of control. Facilities may combine several captured VOC-laden streams and duct them
to a single control device.
Add-on Control Systems
Add-on controls reduce the amount of VOC emissions by either destruction or recovery
with or without recycling of VOC emission in the exhaust streams. Two categories of add-on
control devices are typically used by the automobile and light-duty truck assembly coatings
operations: combustion (thermal or catalytic oxidation) and recovery (adsorption). While many
types of control devices can be used to reduce VOC emissions, the following summary covers
those control devices known to be used with automobile and light-duty truck surface coating
operations: oxidation and hybrid systems (concentrator followed by an oxidizer).
Oxidation destroys VOC emissions in an exhaust stream by exposing the stream to an
oxidizing atmosphere at high temperatures. Oxidizers are typically used in the automobile and
light-duty truck surface coating industry to control bake oven exhaust emissions. Oxidizers may
be of thermal or catalytic design and .combust VOC-containing exhaust streams. Catalytic
oxidizers are similar to thermal oxidizers but employ a catalyst to aid in the oxidation reaction.
As a result, catalytic oxidizers operate at lower combustion temperatures relative to that required
in thermal oxidizers. Both types of oxidizers generally utilize either regenerative or recuperative
techniques to preheat inlet gas in order to decrease energy costs associated with high oxidation
temperatures. They may also use primary or secondary heat recovery to reduce energy
consumption. In general, oxidizers may achieve destruction efficiencies of greater than 95
percent as applied to coating application operations with high and constant concentrations of
VOC.
Hybrid systems consist of a concentrator followed by an oxidizer. Hybrid systems are
used in the automobile and light-duty truck surface coating industry to control spray booth
exhaust emissions, most often exhaust from automated zones of the spray booth. The
concentrator is typically a carbon or zeolite rotor. The concentrator reduces the volume and
increases the VOC concentration of the inlet stream to the oxidizer.
Spray booth exhaust contains overspray particles. The majority of these particles are
removed by the spray booth water wash. Additional pretreatment of the spray booth exhaust is
required before it passes through a concentrator. This additional pretreatment may be done with
dry filters or a dry electrostatic precipitator.
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In addition, there are other control technologies known to reduce VOC emissions, but
they are not currently being used in the automobile and light-duty truck surface coating industry.
These alternative control technologies include condensation, biofiltration, and UV oxidation. .
B. Available Controls for VOC Emissions from Cleaning Materials
Pollution prevention measures, such as work practices, are the most common emission control
technique for reducing VOC emissions from cleaning materials. Work practice procedures
reduce VOC emission during cleaning operations by reducing the amount of VOC that can
evaporate due to exposure to air. Product substitution/reformulation is another type of pollution
prevention measures.
No add-on control technologies are being used specifically for reducing VOC emissions
from cleaning operations associated with automobile and light-duty truck assembly coating.
However, if cleaning operations are performed within a capture system that is ducted to an add-
on control system, the VOC emissions from the cleaning operations would be reduced by the
add-on control.
1. Product Substitution/Reformulation
Reducing the composite VOC vapor pressure or VOC content of the cleaning material
used, either by substitution or reformulation, is one pollution prevention measure that is used to
reduce VOC emissions from cleaning operations. However, there is insufficient information
available to correlate VOC content or vapor pressure to specific cleaning steps.
2. Work Practice Procedures
Work practice procedures are commonly used in the automobile and light-duty truck
manufacturing industry to reduce VOC emissions from cleaning operations. These procedures
include the following:
Cover mixing and storage vessels for VOC-containing cleaning materials and
cleaning waste materials, except when adding, removing, or mixing contents;
• Use closed containers or pipes to store and convey VOC-containing cleaning
and cleaning waste materials;
. Minimize spills of VOC-containing cleaning and cleaning waste materials; and
• Minimize VOC emissions during cleaning operations.
C. Existing Federal, State, and Local Recommendations or Regulations
The following discussion is a summary of three EPA actions, as well as State and local
regulations, which address VOC emissions from automobile and light-duty truck assembly
coating processes.
Three previous EPA actions affected automobile and light-duty truck assembly coating
operations:
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CTG for Surface Coating of Cans, Coils, Paper, Fabrics, Automobiles, and Light-Duty
Trucks (1977).
New Source Performance Standard for Automobile and Light- Duty Truck Surface
Coating Operations, 40 CFR Part 60, subpart MM (1980).
National Emission Standards for Hazardous Air Pollutants for Surface Coating of
Automobile and Light-Duty Trucks, 40 CFR 63, subpart IIII (2004).
1.
The 1977 CTG
In 1977, EPA issued a CTG document entitled "Control of Volatile Organic Emissions
from Existing Stationary Sources Volume II: Surface Coating of Cans, Coils, Paper, Fabrics,
Automobiles, and Light-Duty Trucks. (EPA-450/2-77-008) The 1977 CTG. and subsequent
implementation guidance provided RACT recommendations for controlling VOC emissions
from automobile and light-duty truck assembly surface coating operations. These
recommendations are summarized in Table 1.
The subsequent implementation guidance included the publication in 1988 of a
document titled "Protocol for Determining the Daily Volatile Organic Compound Emission Rate
of Automobile and Light-Duty Truck Topcoat Operations" (EPA-450/3-88-018). This
document is commonly referred to as the Automobile Topcoat Protocol. The Automobile
Topcoat Protocol provides procedures and calculations for determining the daily VOC emission
rate of automobile and light-duty truck topcoat operations. These procedures and calculations
can also be applied to primer-surfacer operations. Most automobile and light-duty truck
facilities use the 1988 protocol for both their topcoat and primer-surfacer operations.
Table 1. 1977 CTG Recommended VOC Emission Limits for Automobile and Light-Duty
Truck Surface Coatings
Electrodeposition
primer operation
Primer-surfacer
(guidecoat) operation
Topcoat operation
Final repair operation
0.14 kg VOC/liter (1.2 Ibs/gal) of coating, excluding water and
exempt compounds8, or
0.17 kg VOC/liter (1.4 Ib VOC/gallon) of coating solids deposited
1.8 kg VOC/liter (15.1 Ib VOC/gallon) of coating solids deposited on
a daily average basis as determined by following the procedures in the
Automobile Topcoat Protocol.
1.8 kg VOC/liter (15.1 Ib VOC/gallon) of coating solids deposited on
a daily average basis as determined by following the procedures in the
Automobile Topcoat Protocol.
0.58 kg VOC/liter (4.8 Ibs/gal) of coating, excluding water and
exempt compounds
e Exempt compounds are those classified by EPA as having negligible photochemical reactivity as listed in 40 CFR
51.100 (s). Exempt compounds are not considered to be VOC.
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2.
The 1980 NSPS
In 1980, EPA promulgated an NSPS for surface coating of automobile and light-duty
trucks (40 CFR part 60 subpart MM). The NSPS established the emission limits calculated on a
monthly basis for each primecoat operation, guidecoat (primer-surfacer) operation, and topcoat
operation located in an automobile or light-duty truck assembly plant constructed, reconstructed,
or modified after October 5, 1979 (Table 2). The NSPS does not apply to plastic body
component coating operations or to all-plastic automobile or light-duty truck bodies coated on
separate coating lines. The VOC emission limit for primecoat operations depends on the solids
turnover ratio (/?,). The solids turnover ratio is the ratio of total volume of coating solids added
to the EDP system in a calendar month to the total volumetric design capacity of the EDP
system. The NSPS limits and the 1977 CTG recommendations for primer-surfacer and topcoat
cannot be directly compared because of differences in the compliance period (monthly for the
NSPS limits and daily for the CTG recommendations) and how transfer efficiency is considered
(table values for the NSPS limits and actual transfer efficiency testing for the CTG
recommendations).
Table 2. 1980 NSPS VOC Emission Limits for Automobile and Light-duty Truck
Surface Coatings
Primecoat Operations
(Non-EDP)
0.17 kg VOC/liter (1.42 Ib/gal) coating solids applied
When solids turnover
ratio (Rrf>Q. 16:
Primecoat Operations
(EDP)
0.17 kg VOC/liter
(1.42 Ib/gal) coating
solids applied
When
0.040<#7<0.160:
0.17x350™^
VOC/liter
(0.17x350° 16(WVx
8.34 Ib/gal)
coating solids
applied
When tf 7<0.040:
No VOC emission
limit
Guidecoat Operations
(including the
guidecoat application,
flash-off area, and
oven)
1.40 kg VOC/liter (11.7 Ib/gal) coating solids applied
Topcoat Operations
(including topcoat
application, flash-off
area, and oven)
1.47 kg VOC/liter (12.3 Ib/gal) coating solids applied
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3.
The 2004 NESHAP
In 2004, EPA promulgated the National Emissions Standards for Hazardous Air
Pollutants: Surface Coating of Automobile and Light-Duty Trucks, 40 CFR, part 63, subpart IIII.
The areas covered by the NESHAP include all the equipment used to apply coating to new
automobile or light-duty truck bodies or body parts and to dry or cure the coatings after
application; all storage containers and mixing vessels in which vehicle body coatings, thinners,
and cleaning materials are stored and 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 to convey waste
materials generated by an automobile and light-duty truck assembly coating operation.
The 2004 NESHAP for automobile and light-duty truck assembly coating imposed
organic HAP emission limitations calculated on a monthly basis for existing sources. More
stringent limits apply to new sources (i.e., sources that commenced construction after December
24, 2002). The NESHAP also sets emission limits for coatings not included in the CTG or
NSPS, including glass bonding primer, glass bonding adhesive, and some coatings and thinners.
The limits for automobile and light-duty truck assembly coating for existing and new sources are
summarized in Table 3 below.
Table 3. 2004 NESHAP HAP Emission Limits for Automobile and Light-Duty
Truck Surface Coatings
Combined primer-surfacer, topcoat, final
repair, glass bonding primer, and glass
bonding adhesive operation plus all
coatings and thinners, except for deadener
materials and for adhesive and sealer
materials that are not components of glass
bonding systems, used in coating
operations added to the affected source
0.060 kg organic HAP/liter of coating
solids deposited (0.50 Ib/gal) for new or
reconstructed affected sources
0.132 kg organic HAP/liter of coating
solids deposited (1.10 Ib/gal) for existing
affected sources
Combined electrodeposition primer,
primer-surfacer, topcoat, final repair, glass
bonding primer, and glass bonding
adhesive operation plus all coatings and
thinners, except for deadener materials and
for adhesive and sealer materials that are
not components of glass bonding systems,
used in coating operations added to the
affected source
0.036 kg organic HAP/liter of coating
solids deposited (0.30 Ib/gal) for new or
reconstructed affected sources
0.072 kg organic HAP/liter of coating
solids deposited (0.60 Ib/gal) for existing
affected sources
The 2004 NESHAP for automobile and light-duty truck assembly coating also
specified work practices to minimize organic HAP emissions from the storage, mixing, and
conveying of coatings, thinners, cleaning materials, and from handling waste materials
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generated by the coating operation.
4. Existing State and Local VOC Requirements
In addition to the EPA actions described above, at least 14 States and one California
air pollution control district have regulations that control VOC emissions from automobile
and light-duty truck assembly coating.
Most of the state rules reviewed had limits that are consistent with the 1977 CTG
recommended limits. The state rules are summarized in Appendix C.
VI. Recommended Control Techniques
This CTG recommends the following VOC reduction measures: VOC emission limits for
coating operations; work practices for storage and handling of coatings, thinners, and coating
waste materials; and work practices for the handling and use of.cleaning materials.
During the development of the 2004 NESHAP, EPA identified 61 automobile and light-
duty truck assembly facilities operating in 1999. In 2008, the Alliance of Automobile
Manufacturers, an industry trade association representing the majority of these facilities,
provided EPA information from its member companies. Non-member companies also submitted
information to EPA. EPA reviewed and evaluated this information in conjunction with
developing this CTG. In total, EPA received information for 52 facilities. The information
included VOC emission rates for EDP, primer-surfacer, and topcoat operations on a daily and
monthly average for the calendar years 2006 and 2007. Most facilities also provided data
showing maximum and minimum daily values, as well. The VOC emission limits recommended
in this CTG are based on 2006 and 2007 data from currently operating automobile and light-duty
truck assembly coating operations, and the work practices recommendations mirror those found
in the NESHAP.
For cleaning materials, we are recommending work practices to reduce VOC emissions.
We do not have information available to correlate VOC content or vapor pressure to specific
cleaning steps. Therefore, we are not recommending VOC content or VOC composite vapor
pressure limits for cleaning materials.
The following discussion summarizes our specific recommendations for coating
operations and cleaning materials used in automobile and light-duty truck assembly coating
operations.
A. Coatings
The following VOC emission limits are recommended to reduce VOC emissions
from the coatings during the coating operations (Table 5). The categories reflect the current
processes that are used at automobile and light-duty truck assembly coating facilities. For
all the operations, except for final repair, the recommended limits are based on data supplied
by the Alliance of Automobile Manufacturers member companies and non-member
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companies in 2008.
The recommended limits for electrodeposition primer, primer-surfacer and topcoat
are more stringent than State rules, most of which are based on the 1977 CTG and or the
NSPS limits. For final repair operations, no information was presented in the industry
submittals. Therefore, we chose to recommend the limits for final repair recommended in
the 1977 CTG. Additionally, an alternative emission limit for combined primer-surfacer and
topcoat applications is recommended because in some facilities these processes are
becoming progressively indistinguishable from each other.
For electrodeposition primer the recommended limit uses the same emission limit
format as the NSPS. In addition, we recommend that facilities determine the VOC emission
rate from electrodeposition primer using the same monthly weighted averaging approach as
that provided in the NSPS. The electrodeposition primer system includes a large dip tank
which may contain up to 100,000 gallons of coating. Material additions are typically made
every few days to replenish the system and to maintain the material in the system at a near
constant mix. During periods of low production, additional solvent may need to be added
to maintain the system. The NSPS emission limit format and monthly weighted averaging
approach takes these practices into account. For these reasons, we suggest the NSPS
emission limit format and monthly weighted averaging approach be used with our RACT
recommendation for electrodeposition primer.
For primer-surfacer, topcoat, and combined primer-surfacer and topcoat, the
recommended limits are expressed as a daily weighted average as determined by following
the procedures in the revised Automobile Topcoat Protocol. In conjunction with this CTG
we have revised the Automobile Topcoat Protocol. The revised protocol includes new
sections on accounting for control of spray booth emissions and instructions for applying the
protocol to primer-surfacer operations. We recommend that facilities refer to the procedures
and calculations in the revised protocol for determining the daily VOC emission rate of
automobile and light-duty truck primer-surfacer and topcoat operations.
For final repair our recommended limit is expressed as a daily weighted average or an
occurrence weighted average. An occurrence weighted average is a simplified averaging
approach for individual repairs. Our recommendation for an occurrence weighted average for
final repair is to give clear coat a weighting factor of two and give each other coating used in the
repair a weighting factor of one. For an example, see Bay Area Air Quality Management
District, Regulation 8 Rule 45, Section 8-45-227, January 6, 1999.
States may wish to consider the use of longer averaging times for primer-surfacer,
topcoat, combined primer-surfacer and topcoat, or final repair. EPA generally recommends
that States apply RACT on a short-term basis up to 24 hours.h However, EPA has issued
h See, e.g., 52 FR 45108, col. 2, "Compliance Periods" (November 24, 1987). "VOC rules should describe explicitly
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guidance that addresses averaging times longer than 24 hours under certain conditions.1
The EPA's "Economic Incentive Policy"-* provides guidance on use of long-term averages
with regard.to RACT and generally provides for averaging times of no greater than 30 days.
Because of the nature of averaging, however, we recommend that any State RACT Rules
that allow for averaging include appropriate recordkeeping and reporting requirements.
Table 5. Recommended VOC Emission Limits for Automobile and Light-Duty Truck
Assembly Coatings
Assembly Coating Process
Recommended VOC Emission Limit
Electrodeposition primer
(EDP) operations (including
application area, spray/rinse
stations, and curing oven)
When solids
turnover ratio
(/Zr)>0.16:
0.084 kg
VOC/liter (0.7
Ib/gal) coating
solids applied.
When
0.040<#7<0.160:
,0.1 bO-K
0.084x350'
VOC/liter (0.084x3~50°'m'RT
x 8.34 Ib/gal) coating solids
applied.
When
No VOC
emission
limit.
1.44 kg of VOC/liter of deposited solids (12.0 Ibs VOC/gal
deposited solids) on a daily weighted average basis as
determined by following the procedures in the revised
Automobile Topcoat Protocol.3
Primer-surfacer operations
(including application area,
flash-off area, and oven)
Topcoat operations (including
application area, flash-off
area, and oven)
1.44 kg VOC/liter of deposited solids (12.0 Ib VOC/gal
deposited solids) on a daily weighted average basis as
determined by following the procedures in the revised
Automobile Topcoat Protocol.
Final repair operations
0.58 kg VOC/liter (4.8 Ib VOC/gallon of coating) less water and
less exempt solvents on a daily weighted average basis or as an
occurrence weighted average.
Combined primer-surfacer
and topcoat operations
1.44 kg VOC/liter of deposited solids (12.0 Ib VOC/gal
deposited solids) on a daily weighted average basis as
determined by following the procedures in the revised
Automobile Topcoat Protocol.
the compliance timeframe associated with each emission limit (e.g., instantaneous or daily). However, where the
rules are silent on compliance time, EPA will interpret it as instantaneous."
' Memorandum from John O'Connor, Acting Director of the Office of Air Quality Planning and Standards, January
20, 1984, "Averaging Times for Compliance with VOC Emission Limits—SIP Revision Policy."
J "Improving Air Quality with Economic Incentive Programs, January 2001," available at
http://www.epa.goV/ttn/oarpg/t 1 /memoranda/eipfin.pdf.
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Table 6. Recommended VOC Emission Limits for Miscellaneous Materials Used at
Automobile and Light-Duty Truck Assembly Coating Facilities (grams of VOC per liter of
coating excluding water and exempt compounds , as applied)
Material
Automobile and light-duty truck glass bonding primer
Automobile and light-duty truck adhesive
Automobile and light-duty truck cavity wax
Automobile and light-duty truck sealer
Automobile and light-duty truck deadener
Automobile and light-duty truck gasket/gasket sealing material
Automobile and light-duty truck underbody coating
Automobile and light-duty truck trunk interior coating
Automobile and light-duty truck bedliner
Automobile and light-duty truck weatherstrip adhesive
Automobile and light-duty truck lubricating wax/compound
Recommended VOC
Emission Limit
900 g VOC/liter
250 g VOC/liter
650 g VOC/liter
650 g VOC/liter
650 g VOC/liter
200 g VOC/liter
650 g VOC/liter
650 g VOC/liter
200 g VOC/liter
750 g VOC/liter
700 g VOC/liter
We are recommending that the VOC emission limits not be applied to materials supplied
in containers with a net volume of 16 ounces or less, or a net weight of one pound or less.
We also recommend that the VOC content of coatings, other than reactive adhesives,
used at automobile and light-duty truck coatings assembly coatings facilities be determined
using EPA Method 24. We recommend that the procedure for reactive adhesives in
Appendix A of the NESHAP for surface coating of plastic parts (40 CFR Part 63, subpart
PPPP) be used to determine the VOC content of reactive adhesives. In addition, we
recommend that manufacturer's formulation data be accepted as an alternative to these
methods. If there is a disagreement between manufacturer's formulation data and the results
of a subsequent test, we recommend that States use the test method results unless the facility
can make a demonstration to the States' satisfaction that the manufacturer's formulation data
are correct.
Additionally, the CTG recommends work practices to reduce emissions from coating
operations, such as covering open containers.
Exempt compounds are those classified by EPA as having negligible photochemical reactivity as listed in 40 CFR
51.100(s). Exempt compounds are not considered to be VOC.
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The recommended emission limits for primer-surfacer and topcoat operations can be
achieved with a combination of higher-solid solvent-borne coatings, efficient application
equipment and bake oven exhaust control. The primer-surfacer and topcoat operations at many
facilities are performing significantly better than the recommended emission limits by using
some combination of powder primer-surfacer, waterborne primer-surfacer or basecoat, and
partial control of spray booth exhaust (principally from automated spray booth zones). The cost
and cost-effectiveness of retrofitting or converting a facility using higher-solid solvent-borne
coatings, efficient application equipment and bake oven exhaust control to one that uses powder
primer-surfacer, waterborne primer-surfacer or basecoat, or partial control of spray booth
exhaust, is not believed to be reasonable in the context of RACT.
B. Work Practices for Coating-Related Activities and Cleaning Materials
In addition to the control options above, this CTG recommends work practices to further
reduce VOC emissions from automobile and light-duty truck assembly coating-related activities.
Although VOC reductions achieved by implementing the work practices that we recommend for
these coating-related activities may not be quantifiable, they are beneficial to the overall goal of
reducing VOC emissions.
We recommend work practices for storage, mixing, and handling operations for coatings,
thinners, and coating-related waste materials. Specifically, we recommend the following work
practices: (1) store all VOC-containing coatings, thinners, and coating-related waste materials in
closed containers; (2) ensure that mixing and storage containers used for VOC-containing
coatings, thinners, and coating-related waste materials are kept closed at all times except when
depositing or removing these materials; (3) minimize spills of VOC-containing coatings,
thinners, and coating-related waste materials; (4) convey VOC-containing coatings, thinners, and
coating-related waste materials from one location to another in closed containers or pipes; and (5)
minimize VOC emission from cleaning of storage, mixing, and conveying equipment.
Additionally, we recommend that each facility develop and implement a work practice
plan to minimize VOC emissions from cleaning and from purging of equipment associated with
all coating operations for which emission limits are recommended in this CTG. We recommend
that the plan specify practices and procedures to ensure that VOC emissions 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.)
The 2004 NESHAP similarly requires development and implementation of a work
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practice plan for reducing HAP emissions. If a facility covered by this CTG already has a
NESHAP work practice plan in place, instead of creating another work practice plan to address
VOC emissions, we recommend that the facility simply add to its NESHAP work practice plan
procedures for minimizing non-HAP VOC emissions. Most elements of the NESHAP work
practice plan, which is directed at reducing organic HAP, are also consistent with reducing VOC
emissions. Therefore, there is no need to create another work practice plan to address VOC
emissions.
VII. Emission Reductions and Cost Effectiveness of Recommended Control Options
Based on information supplied by the Alliance of Automobile Manufacturers and other
manufacturers , we estimated that there are a total of 52 automobile and light-duty truck
assembly plants in the U.S. Using the 2004 ozone nonattainment designations, we determined
that 33 of these facilities are in ozone nonattainment areas. The 2002 National Emissions
Inventory (NEI) contains information for 32 of these 33 facilities. These 32 facilities reported
actual VOC emissions totaling approximately 19,500 tons in 2002.
Auto and light-duty truck coating facilities have reduced the VOC emissions from their
coating operations to comply with the NSPS, NESHAP, and State rules. The recommended
VOC emission rates described above reflect the control measures that are currently being
implemented by these facilities. Consequently, there is no additional cost to implement the CTG
recommendations for coatings. For the same reason, we do not anticipate additional VOC
emission reduction from coatings.
The CTG also recommends work practices for reducing VOC emissions from both
coatings and cleaning materials. We believe that our work practice recommendations in the
CTG will result in a net cost savings. Implementing work practices reduces the amount of
coatings and cleaning materials used by decreasing evaporation.
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VIII. References
1. Control of Volatile Organic Emissions from Existing Stationary Sources - Volume II:
Surface Coating of Cans, Coil, Paper, Fabrics, Automobiles, and Light-Duty Trucks.
Publication No. EPA-450/2-77-008. U. S. Environmental Protection Agency, Research
Triangle Park, NC. May 1977. The cover page of this document is presented in
Appendix B. The full document is available as a separate item in docket EPA-HQ-OAR-
2008-0413 at www.regulations.gov .
2. U.S. Environmental Protection Agency. Standards of Performance for Automobile and
Light-Duty Truck Surface Coating Operations. 40 CFR part 60, subpart MM.
3. U.S. Environmental Protection Agency. National Emission Standards for Hazardous Air
Pollutants: Surface Coating of Automobiles and Light-Duty Trucks. 40 CFR part 63,
subpart IIII.
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Appendix A
Definitions
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Definitions
Adhesive means any chemical substance that is applied for the purpose of bonding two surfaces
together other than by mechanical means.
Automobile and light-duty truck adhesive means an adhesive, including glass bonding
adhesive, used at an automobile or light-duty truck assembly coating facility, applied for the
purpose of bonding two vehicle surfaces together without regard to the substrates involved.
Automobile and light-duty truck bedliner means a multi-component coating, used at an
automobile or light-duty truck assembly coating facility, applied to a cargo bed after the
application of topcoat and outside of the topcoat operation to provide additional durability and
chip resistance.
Automobile and light-duty truck cavity wax means a coating, used at an automobile or light-
duty truck assembly coating facility, applied into the cavities of the vehicle primarily for the
purpose of enhancing corrosion protection.
Automobile and light-duty truck deadener means a coating, used at an automobile or light-
duty truck assembly coating facility, applied to selected vehicle surfaces primarily for the
purpose of reducing the sound of road noise in the passenger compartment.
Automobile and light-duty truck gasket/gasket sealing material means a fluid, used at an
automobile or light-duty truck assembly coating facility, applied to coat a gasket or replace and
perform the same function as a gasket. Automobile and light-duty truck gasket/gasket sealing
material includes room temperature vulcanization (RTV) seal material.
Automobile and light-duty truck glass bonding primer means a primer, used at an automobile
or light-duty truck assembly coating facility, applied to windshield or other glass, or to body
openings, to prepare the glass or body opening for the application of glass bonding adhesives or
the installation of adhesive bonded glass. Automobile and light-duty truck glass bonding primer
includes glass bonding/cleaning primers that perform both functions (cleaning and priming of the
windshield or other glass, or body openings) prior to the application of adhesive or the
installation of adhesive bonded glass.
Automobile and light-duty truck lubricating wax/compound means a protective lubricating
material, used at an automobile or light-duty truck assembly coating facility, applied to vehicle
hubs and hinges.
Automobile and light-duty truck sealer means a high viscosity material, used at an automobile
or light-duty truck assembly coating facility, generally, but not always, applied in the paint shop
after the body has received an electrodeposition primer coating and before the application of
subsequent coatings (e.g., primer-surfacer). The primary purpose of automobile and light-duty
truck sealer is to fill body joints completely so that there is no intrusion of water, gases or
corrosive materials into the passenger area of the body compartment. Such materials are also
referred to as sealant, sealant primer, or caulk.
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Automobile and light-duty truck trunk interior coating means a coating, used at an
automobile or light-duty truck assembly coating facility outside of the primer-surfacer and
topcoat operations, applied to the trunk interior to provide chip protection.
Automobile and light-duty truck underbody coating means a coating, used at an automobile
or light-duty truck assembly coating facility, applied to the undercarriage or firewall to prevent
corrosion and/or provide chip protection.
Automobile and light-duty truck weatherstrip adhesive means an adhesive, used at an
automobile or light-duty truck assembly coating facility, applied to weatherstripping materials
for the purpose of bonding the weatherstrip material to the surface of the vehicle.
Electrodeposition primer means a process of applying a protective, corrosion-resistant
waterborne primer on exterior and interior surfaces that provides thorough coverage of recessed
areas. It is a dip coating method that uses an electrical field to apply or deposit the conductive
coating onto the part. The object being painted acts as an electrode that is oppositely charged
from the particles of paint in the dip tank. Also referred to as E-Coat, Uni-Prime, and ELPO
Primer.
Final repair means the operations performed and coating(s) applied to completely-assembled
motor vehicles or to parts that are not yet on a completely assembled vehicle to correct damage
or imperfections in the coating. The curing of the coatings applied in these operations is
accomplished at a lower temperature than that used for curing primer-surfacer and topcoat. This
lower temperature cure avoids the need to send parts that are not yet on a completely assembled
vehicle through the same type of curing process used for primer-surfacer and topcoat and is
necessary to protect heat sensitive components on completely assembled vehicles.
In-line repair means the operation performed and coating(s) applied to correct damage or
imperfections in the topcoat on parts that are not yet on a completely assembled vehicle. The
curing of the coatings applied in these operations is accomplished at essentially the same
temperature as that used for curing the previously applied topcoat. Also referred to as high bake
repair or high bake reprocess. In-line repair is considered part of the topcoat operation.
Primer-surfacer means an intermediate protective coating applied over the electrodeposition
primer and under the topcoat. Primer-surfacer provides adhesion, protection, and appearance
properties to the total finish. Primer-surfacer may also be called guide coat or surfacer. Primer-
surfacer operations may include other coating(s) (e.g., anti-chip, lower-body anti-chip, chip-
resistant edge primer, spot primer, blackout, deadener, interior color, basecoat replacement
coating, etc.) that is (are) applied in the same spray booth(s).
Topcoat means the final coating system applied to provide the final color and/or a protective
finish. The topcoat may be a monocoat color or basecoat/clearcoat system. In-line repair and
two-tone are part of topcoat. Topcoat operations may include other coating(s) (e.g., blackout,
interior color, etc.) that is (are) applied in the same spray booth(s).
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Solids turnover ratio (R /•) means the ratio of total volume of coating solids that is added to the
EDP system in a calendar month divided by the total volume design capacity of the EDP system.
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Appendix B
1977 CTG for Surface Coating of Cans, Coils, Paper, Fabrics, Automobiles, and Light-
Duty Trucks
The cover page of this document is presented here. The full document is available as a
separate item in docket EPA-HQ-OAR-2008-0413 at www.regulations.gov .
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EPA-450/2-77-Q08
May 1977
(OAQPS NO. 1.2-073)
CAN COATING
,\r -42
Section 4.2.2
OAQPS GUIDELINES
CONTROL OF VOLATILE
ORGANIC EMISSIONS
FROM- EXISTING
STATIONARY SOURCES -
VOLUME II: SURFACE COATING
OF CANS, COILS, PAPER,
pfe FABRICS, AUTOMOBILES,
-AND LIGHT-DUTY TRUCKS
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Ak Quality Planning and Standards
Research Triangle Park, North Carolina 27711
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Appendix C
Summary of Selected State Regulations for Automobile and Light-Duty Truck Assembly
Coatings (including Bay Area AQMD)
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State
.Alabama
Delaware
Illinois
Indiana
Kansas
Kentucky
Louisiana
Michigan
Mississippi
Regulation
335-3-6-.il
Reg 24, Sec 13
Title 35, part 21 5
326IAC8-1
KAR 28-19-63
401KAR61:090
LAC 33:111.2123
R336.1610
Standards
Prime
1.21b/GCEWE
EDP:
Same as NSPS
1.2 Ib/GCEWE
1.21b/gal
Chicago and Metro East:
1.21b/gal
l.91b/GCEWE
1.21b/GCEWE
EDP:
1.21b/GCEWE,
OR
>55 vol% solids organic-
•borne prime coat applied
with >50% TE.
Primer-surfacer
2.8 Ib/GCEWE
2.8 Ib/GCEWE as applied
15.1 Ib/GSA
2.8 Ib/gal
Chicago and Metro East:
15.1 Ib/gal
2.8 Ib/GCEWE
15.1 Ib/GSA
2.8 lb/ GCEWE,
OR
>55 vol% solids organic-
borne prime coat applied
with >65% TE,
OR
15.1 Ib/GSA
Topcoat
2.8 Ib/GCEWE
2.8 Ib/GCEWE as applied
15.1 Ib/GSA
2.8 Ib/gal
Chicago and Metro East:
15.1 Ib/gal
2.8 Ib/GCEWE
2.8 Ib/GCEWE
15.1 Ib/GSA
2.8 Ib/GCEWE,
OR
>50 vol% solids organic-
borne prime coat applied
with >65% TE,
OR
15.1 Ib/GSA
Final Repair
4.8 Ib/GCEWE
4.8 Ib/GCEWE as applied
34.2 Ib/GSA
4.8 Ib/gal
4.8 Ib/GCEWE
4.8 Ib/GCEWE
4.8 lb/ GCEWE,
AND
>65% TE.
If coatings limits on operations are not met, then <15 wt% of the VOCs net input into the affected facility. Low-use
coatings are exempt from this limit if the plantwide consumption of these coatings in the aggregate is less than or equal
to fifty-five (55) gallons during the previous twelve (12) months.
1.21b/GCEWE
1.21b/GCEWE
2.8 Ib/GCEWE as applied
15.1 Ib/GSA
14.9 Ib/GSA
2.8 Ib/GCEWE as applied
15.1 Ib/GSA
14.9 Ib/GSA
4.8 Ib/GCEWE
4.8 Ib/GCEWE
No Regulation
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State
Missouri
Ohio
Bay Area AQMD
South Carolina
Regulation
10CSR10-
2.230
10CSR 10-
5.330
3745-21-09
Reg 8, Rule 13
Reg 61-62.60
Standards
Prime
KC Metro Area:
Ford and GM: Prime
w/EDP: 1 .2 Ib/GCEWE
STL Metro Area:
15.1 Ib/gal of solids applied
Chrysler: Prime w/EDP:
1 .2 Ib/gal of coating
excluding water and
exempts; Prime: 2.8 Ib/gal
Ford: Prime w/EDP: 1 .2
Ib/gal of coating excluding
water and exempts; Prime:
3.2 Ib/gal
GM: Prime w/EDP: 1.2
Ib/gal of coating excluding
water and exempts
EDP:
Same as NSPS
Non-EDP Prime:
1.91b/GCEWE, or
2.6 Ib/GS w/control
EPP:
1.21b/GCEWE, or
90% CE
Primer-surfacer
KC Metro Area:
Ford and GM: 15.1
Ib/GAS, orforGM, 3.0
Ib/GCEWE
STL Metro Area:
15.1 Ib/gal of solids applied
Chrysler and GM: 2.8
Ib/gal of coating excluding
water and exempts
Ford: 3.2 Ib/gal of coating
excluding water and
exempts
Guidecoat or surfacer
coating:
2.8 Ib/GCEWE, or
15.1 Ib/GSA
15.01b/GSA
Topcoat
KC Metro Area:
Ford and GM: 15.1 Ib/gal
of solids applied, or
Ford: 3.6 Ib/gal of coating
excluding water and
exempts;
GM: 5.0 Ib/gal of coating
excluding water and
exempts
STL Metro Area:
15.1 Ib/gal of solids applied
Chrysler: 2.5 Ib/gal of
coating excluding water
and exempts
Ford: 3.6 Ib/gal of coating
excluding water and
exempts
GM: 2.8 Ib/gal of coating
excluding water and
exempts
2.8 Ib/GCEWE, or
15.1 Ib/GAS
15.01b/GSA
Final Repair
KC Metro Area:
Ford and GM: 4.8 Ib/gal of
coating excluding water
and exempts
STL Metro Area:
Chrysler, Ford, GM: 4.8
Ib/gal of coating excluding
water and exempts
4.8 Ib/GCEWE, or
13.8 Ib/GS w/control
4.8 Ib/GCEWE
Flexible Parts: Offline Coatings:
1 . Flexible primer: 4. 1 Ib/GCEWE 2.8 Ib/GCEWE, or
2. Clear topcoat: 3.8 Ib/GCEWE 90% CE.
3. Basecoat/clearcoat: 4.5 Ib/GCEWE
OR, 90% CE.
NSPS
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State
Tennessee
Texas
Wisconsin
Regulation
1200-3-18-.il
Chapter 115
NR 422.09
Standards
Prime
EDP:
Same as NSPS
Non-EDP Prime:
l.91b/GCEWE, or
2.6 Ib/GS w/control
1.21b/GCEWE
EDP:
1.21b/GCEW
Primer-surfacer
Guidecoat or surfacer
coating:
2.8 Ib/GCEWE, or
15.1 Ib/GSA
2.8 Ib/GCEWE, or
15.1 Ib/GSA
2.8 Ib/GCEW
Topcoat
2.8 Ib/GCEWE, or
15.1 Ib/GSA
2.8 Ib/GCEWE, or
15.1 Ib/GSA
2.8 Ib/GCEW
Final Repair
4.8 Ib/GCEWE, or
13. 8 Ib/GS w/control
4.8 Ib/GCEWE
4.8 Ib/GCEW
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CE = control efficiency
EDP = electrodeposition primer
EPP = electrophoretic primer
GGEW = gallon of solids excluding water
GCEWE = gallon of coating excluding water and exempt compounds
GS = gallon of solids
GSA = gallon of solids applied
NSPS = New Source Performance Standard (40 CFR 60, subpart MM)
R: = Solids Turnover Ratio
TE = Transfer Efficiency
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United States Office of Air Quality Planning and Standards Publication No. EPA 453/R-08-006
Environmental Protection Sector Policies and Programs Division September 2008
Agency Research Triangle Park, NC
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