Control Techniques Guidelines for Automobile and Light-Duty Truck

Assembly CoatingsEPA-453/R-08-006September 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

iiiTABLE OF CONTENTS

I.II.III.IV. A.

No

V. A. 1.2.B. 1.2.C. 1.2.3.4.VI. A.B.VII.VIII. IntroductionBackground

and Overview 2 Applicability 3 Process Description

and Sources

of VOC Emissions 6 Process Description 7 1. Surface Preparation 7 2. Priming

Operations 7 3. Topcoat

Operations .8 4. Final Repair Operations 8 5. Cleaning

Activities 8 Sources of VOC Emissions 9 1. Coatings 9 2. Cleaning

Materials 10 Available Controls

and Regulatory

Approaches 11 Available Controls

for VOC Emissions

from Coatings

and Drying 11 Pollution Prevention

Measures 11 Emission Capture

and Add-on

Control

Systems 12 Available Controls

for VOC Emissions

from Cleaning

Materials 14 Product Substitution/Reformulation 14 Work Practice

Procedures 14 Existing Federal,

State, and Local Recommendations

or Regulations 14 The 1977 CTG 15 The 1980 NSPS 16 The 2004 NESHAP 17 Existing State and Local VOC Requirements 18 Recommended Control Techniques 18 Coatings 18 Work Practices

for Coating-Related

Activities

and Cleaning

Materials ..22 Emission Reductions

and Cost Effectiveness

of Recommended

Control Options

23 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)I.

Introduction

Clean Air Act (CAA) section 172(c)(1)

provides

that state 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. See60 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

andlightduty 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

R_ACT 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

basedupon

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,

whe.ther

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,

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 pr6mulgated

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 NESttAP,

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

bythe 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 IVdescribes 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 V! 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. App!icabili

•
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

truck a 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 lb/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 lb/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 b 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

process c. Automobile

and light-duty

truck assembly

"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. The primary coatings are electrodeposition

primer, primer-surfacer,

topcoat, and final repair. These coatings are defined in Appendix

B. Coatings applied during the vehicle assembly process include glass bonding primer, adhesives,

cavity wax, sealer,coatings most commonly

are applied at automobile

or light-duty

truck assembly

plants. ttowever, 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

andLightDuty 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) of the CAA.

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 thcilities that coat bodies and/or body parts for new heavier vehicles d 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. 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).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 replace, ment 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

andlightduty 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 lb/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

datasubmitted in 2008 by the Alliance

of Automobile

Manufacturers

member

companies

andnonmember 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 facilitiesthat

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

andlightduty 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 stationsand

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 tocompletelyassembled 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

ActivitiesCleaning 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 measuresinclude

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.

• 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

ofVOCladen 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

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.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

andlightduty 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

andnonelectrostatic spray techniques. Higher solids solvent-borne

coatings

contain more solids than "conventional"

(pre-1980) solvent-borne coatings.

These coatings

contain less orgal•ic 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

MaterialsCleaning materials

are another source of VOC emitted by automobile

and light dutytruck

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
Exempt compounds

are those classified by EPA as having negligible

photochemical

reactivity

as listed in 40 CFR 1.100 (s). Exempt compounds

are not considered

to be VOC.

11efficiency (i.e., the percentage

of coating solids used that is deposited

onto the substrate).
Product substitution

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

andlightduty 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 SystemsCapture 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

12emissions from automobile

and light-duty

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.

13In 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 altemative

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 anaddon 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:

14CTG 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 Electrodepositionprimer operation
Primer-surfacer(guidecoat) operation Topcoat operation

Final repair operation

0.14 kg VOC/liter

(1.2 lbs/gal) of coating,

excluding

water and exempt compounds

g, or 0.17 kg VOC/liter

(1.4 lb VOC/gallon)

of coating solids deposited 1.8 kg VOC/liter

(15.1 lb 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 lb 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 lbs/gal) of coating,

excluding

water and exempt compounds

Exempt compounds

are those classified by EPA as having negligible

photochemical

reactivity

as listed in 40 CFR 1.100 (s). Exempt compounds

are not considered

to be VOC.

152.

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 (Rt). 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)

Primecoat Operations(EDP)

Guidecoat Operations(including theguidecoat application, flash-off area, andoven)Topcoat Operations(including topcoatapplication, flash-off area, and oven)

0.17 kg VOC/liter

(1.42 Ib/gal) coating solids applied When solids turnover ratio (Rr)>0.16:

0.17 kg VOC/liter(1.42 lb/gal) coating solids applied

When0.040<Rr<0.160:0.17x350°•'°-ur

kgVOC/liter(0.17x350° 16°nr x8.34 lb/gal)coating solidsapplied

When Rr<0:040:

No VOC emissionlimit

1.40 kg VOC/liter

(11.7 lb/gal) coating solids applied

1.47 kg VOC/liter

(12.3 lb/gal) coating solids applied

163.

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 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 0.060 kg organic HAP/liter

of coating solids deposited

(0.50 lb/gal) for new or reconstructed affected

sources
0.132 kg organic HAP/liter

of coating solids deposited

(1.10 lb/gal) for existing affected sources
0.036 kg ofganic HAP/liter

of coating solids deposited

(0.30 lb/gal) for new or reconstructed affected

sources
0.072 kg organic HAP/liter

of coating solids deposited

(0..60 lb/gal) forexisting 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

17generated 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

andlightduty 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

18companies 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 R_ACT on.a short-term

basis up to 24 hours, h However,

EPA has issued
See, e.g., 52 FR 45108, col. 2, "Compliance

Periods" (November

24, 1987). "VOC rules should describe explicitly

19guidance that addresses

averaging

times !onger than 24 hours under certain conditions, The EPA's "Economic

Incentive

Policy ''J 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.

"Fable 5. Recommended

VOC Emission

Limits for Automobile

and Light-Duty

Truck Assembly Coatings
Assembly Coating

Process Recommended

VOC Emission

Limit When solids Electrodeposition primer (EDP) operations

(including application area, spray/rinse stations, and curing oven)

Primer-surfacer operations (including application

area, flash-off area, and oven) Topcoat operations

(including application area, flash-off area, and oven)

Final repair operations

Combined primer-surfacer and topcoat operations turnover

ratio(Rr)>0.16:0.084 kgVOC/liter (0.7lb/gal) coatingsolids applied. When0.040<Rr<0.160:0.084X3500"I60"RT kg VOC/liter (0.084x3

500' 160"R T
x 8.34 lb/gal) coating solids applied.

WhenRr<0.040:

No VOCemissionlimit.
1.44 kg of VOC/liter

of deposited

solids (12.0 lbs VOC/gal deposited solids) on a daily weighted

average basis as determined by following

the procedures

in the revised Automobile Topcoat

Protocol.

a 1.44 kg VOC/liter

of deposited

solids (12.0 lb VOC/gal deposited solids) on a daily weighted

average basis as determined by following

the procedures

in the revised Automobile Topcoat

Protocol. 0.58 kg VOC/liter

(4.8 lb VOC/.gallon

of coating)

less water and less exempt solvents

on a daily weighted

average basis or as an
occurrence weighted

average. 1.44 kg VOC/liter

of deposited

solids (12.0 lb 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." "Improving Air Quality with Economic

Incentive Programs,

January 2001," available at http ://www.epa.gov/ttn/oarpg/t 1/memoranda/eipfin.pd

f.

20Table

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

k as applied)

Material

Recommended

VOC Emission Limit Automobile and light-duty

truck glass bonding

primer 900 g VOC/liter Automobile and light-duty

truck adhesive 250 g VOC/liter Automobile and light-duty

truck cavity wax 650 g VOC/liter Automobile and light-duty

truck sealer 650 g VOC/liter Automobile and light-duty

truck deadener 650 g VOC/liter Automobile and light-duty

truck gasket/gasket

sealing material

200 g VOC/liter Automobile and light-duty

truck underbody

coating 650 g VOC/liter Automobile and light-duty

truck trunk interior coating 650 g VOC/liter Automobile and light-duty

truck bedliner 200 g VOC/liter Automobile and light-duty

truck weatherstrip

adhesive 750 g VOC/liter Automobile and light-duty

truck lubricating

wax/compound 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.

k 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.

21The recommended

emission

limits for primer-surfacer

and topcoat operations

can be achieved with a combinaiion

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

22practice

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.

23VIII.

References
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 docketEPA-HQ-OAR2008-0413 at www.regulations.gov.

U.S. Environmental

Protection

Agency.

Standards

of Performance

for Automobile

and Light-Duty Truck Surface Coating

Operations.

40 CFR part 60, subpart MM.
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.

24Appendix A
DefinitionsDefinitions 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

orlightduty 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

orlightduty 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.

26Automobile 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.

Primersurfacer operations

may include other coating(s)

(e.g., anti-chip,

lower-body

anti-chip,

chipresistant 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).

27Solids

turnover

ratio (RT') 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.

28Appendix B
1977 CTG for Surface

Coating

of Cans, Coils, Paper, Fabrics,

Automobiles,

andLightDuty 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.

29EPA-450/2-77.006.May 1977(OAQPS NO. 1.2-073)

OAqPS

CAN COAT I •GAP- 4•S•¢t io. 4.2.2.¢

GUIDELINES

CONTROL OF VOLATILE ORGANIC EMISSIONS FROM- EXISTING STATIONARY SOURCES. VOLUME II: SURFACE

COATING OF CANS,

COILS,

PAPER, FABRICS, AUTOMOBILES, •;••:•:•=:.•:AND LIGHT-DUTY TRUCKS

U.S, ENVIRONMENTAL

PROTECTION

AGENCY Office of Air and Waste Management Office of Air Quality

Planning

and Standards Research Triangle

Park, North Carolina

27711

 ̧30Appendix C Summary of Selected

State Regulations

for Automobile

and Light-Duty

Truck Assembly Coatings (including

Bay Area AQMD)

31o •

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