GUIDANCE DOCUMENT FOR CORRECTING 

VOC RULE DEFICIENCIES 

U.S. ENVIRONMENTAL PROTECTION AGENCY 

 REGION IX 

CALIFORNIA AIR RESOURCES BOARD 

APRIL 1991 

 Guidance Document for Correcting 

VOC Rule Deficiencies 
Table of Contents 

Introduction................................................................... 1 

Alternative Controls and 

Alternative Methods of Compliance...................... 2 

Capture Efficiency 7 

Compliance Periods / Averaging Times 10 

Compliant Coating and Graphic Arts 

material Emission Limitation Units 13 

Director's Discretion 17 

Recordkeeping Requirements 24 

Source Applicability and Exemptions 27 

Test Methods 30 

Transfer Efficiency ......

VOC Definition...................................................... 33 

................................... 

Appendix A: List of All CTG Categories 

Appendix B: Capture Efficiency Model Rule 

. 3 6 
Introduction 

The purpose of this document is to enhance the ability of districts to develop rules that meet 

State and Federal criteria. This document does not impose any new requirements on districts. 

Rather, it provides examples and additional explanation of policy and enforceability issues 

highlighted in EPA's guidance document, Issues Relating to VOC Regulation Cutpoints, 

Deficiencies, and Deviations (the Bluebook). Because guidance concerning RACT levels of 

stringency is available in the Control Techniques Guidelines (CTG) and summarized in the 

Bluebook, we will not provide a detailed discussion of RACT requirements herein. A listing of 

all CTGs is found in Appendix A. 

This document should be used to review rules that are already adopted as well as consulted 

during the rule development process. If after reading this document, you need additional 

clarification, please contact: 

The State Implementation Plan Section 

Air and Toxics Division 

U.S. EPA, Region 9 

(415) 744-1185 
1 

Alternative Controls and Alternative Methods of Compliance

The use of alternative controls for meeting emission limits is fairly common in California 

volatile organic compound regulations. While alternative controls can provide the source with 

different options for meeting regulatory requirements, they can present enforcement problems 

for the Agencies involved in their oversight. Examples include: equivalency provisions, 

alternative emission control plans (AECPs), cross-line averaging, and any other type of bubble. 

Alternative Controls are generally acceptable to EPA if the rule contains clearly defined 

enforceable language (e.g., calculations, test methods, etc.) such that an EPA inspector can 

readily determine compliance. However, provisions which allow averaging of emissions from 

coating lines or other emission sources must also follow the guidance provided in EPA's 

Emission Trading Policy Statement' (ETPS). lations which contain director's descretion --- 

(DD), or the approval and use –of alternative are not acceptable as State Implementation Plan 

(SIP) revisions unless the rule -- clarifies such approvals submitted to EPA as a source specific 

revision, the rule contains (i.e., not requiring case EPA approval for the alternative means) and 

meets princability and other requirements as described in P5 (51 Federal 50; December 4, 1986). 

 For other examples of director's discretion, please refer to the director's discretion discussion. 

Variances are another alternative method of compliance which are distinct from the methods 

described above. Because variances must meet special administrative requirements, they are 

discussed separately at the end of this section. 

Examples

1. Equivalence or equivalency. Equivalency allows a source to comply by demonstrating an 

equivalent emission reduction, usually through the use of control equipment. However, these 

provisions can be deficient if the methodology for determining equivalence is not clearly 

specified, capture efficiency is not considered, and/or APCO discretion is included in the 

determination. 

-------------------- 

1. With regard to bubbles (and other similar emission trades), the final Emissions Trading 

Policy remains generally in effect. There may, however, be certain circumstances where current 

bubble requirements should be modified or reinterpreted in light of the changed circumstances 

brought about by the Clean Air Act Amendments of 1990. We will attempt to keep 

states/districts appraised of any changes as they arise. 
2 

 Unapprovable provision: 

A person shall not apply any coating with a VOC content in excess of the specified limits, 

expressed as grams of VOC per liter of coating applied, excluding water and exempt 

solvents, unless emissions to the atmosphere are controlled to an equivalent level by air 

pollution abatement equipment with an abatement device efficiency of at least 85 percent. 

In order for an inspector to determine equivalence, the rule should specify the test methods and 

calculations used for determining whether actual emissions would be below the emissions 

expected from compliant coatings. [In addition, the-rule must consider capture efficiency (CE) 

along with the abatement device efficiency. For further discussion of CE requirements, please 

refer to the section on CE.] 

Approvable provision: 

A person shall not apply any coating with a VOC content in excess of the specified limits, 

expressed as grams VOC per liter (lbs/gal) of coating applied, excluding water and exempt 

solvents, unless emissions to the atmosphere are controlled to an equivalent level by air 

pollution abatement equipment with a combined capture and control efficiency of 80 percent 

or greater as needed to achieve an equivalent level of control. Calculations and test methods 

for determining compliance are described under Section XXXX. 

This language is approvable because it considers both capture and control efficiency and 

specifies the calculations and test methods for determining equivalence. 

2. Alternative Emission Control Plans (AECPs). AECPs (aka, Equivalency, Compensating 

Reduction, or Bubble) are provisions which allow a source to achieve equivale - t @mission 

reductions by using emission reduction credits generated at a source(s) within a facility to offset 

noncompliant emissions from another operations within the facility. These provisions can be 

deficient if some or all of the following deficiencies are found in he rule: director's discr-etion,__emi - ss ion.averaging beyond a-24hour peri6d-,-mC6@6-d--olog-y for determining 

compliance not stated in the ru

,ile_- ET-P-S--.-g-uid ance-- 1 owe ' d ' . For can coating operao@ns, refer to "Compliance 

With VOC Emission Limitations for Can Coating Operations" (45 Federal Register 80824). 
Unapprovable provision: 

The requirements of Section XXXX shall not apply to any coating, cleaning, or stripping 

line which complies with an alternative emission control plan which has been approved by 

the APCO and which satisfies the following requirements: 

 1. Emissions of VOCS, on.a daily weighted average, shall be no greater than that amount 

which would result if the affected coating line or lines complied with all applicable requirements 

of this rule ... 

(This example contains only a portion of the actual requirements. Additional requirements such 

as recordkeeping, a complete list of coatings and coating lines, limitations on sources of credit, 

etc., are not included with this example.) 

The previous language is unapprovable because the provision may hinder EPA's ability to 

determine compliance. The APCO (or director's) discretion gives the APCO the authority to 

approve this provision independent of the SIP process. Please see the director's discretion 

section of this document for further information. The provision is not consistent with the ETPS 

requirements, and it lacks enforceable criteria and test methods for an inspector to determine 

compliance. 

Approvable provision: 

The requirements of Section XXXX shall not apply to any coating, cleaning, or stripping 

line which complies with an alternative emission control plan (AECP) which has been approved by the APCO and which satisfies all of the following 

requirements: 

1. AECP approvals shall be submitted to the Environmental Protection Agency as a sourcespecific State Implementation Plan (SIP) revision. For purposes of federal enforceability, an 

AECP is not effective until it is submitted to and approved by the EPA as a revision of the SIP 

pursuant to Section 110 of the Clean Air Act, 42 U.S.C. 7410. 
2. Emissions of VOCs shall be no greater than that amount which would result if the 

affected coating line or lines complied with all applicable requirements of this rule. 

3. In order to calculate emission reductions, each AECP must establish the source's baseline 

emissions, which are the product of the average Emission Rate, Capacity Utilization, and Hours 

of Operation for the previous two years of operation (unless another period is demonstrated to be 

more representative). 

4. Emission reductions used as part of the AECP must be 

surplus, enforceable, permanent, and quantifiable. 

5. Calculations and test methods for determining compliance shall be contained in the 

AECP ... 

 (This example contains only a portion of the actual requirements. Additional requirements such 

as recordkeeping, a complete list of coatings and coating lines, limitations on sources of credit, 

etc., are not included with this example.) 

3. Cross-line Averaging. Cross-line averaging is a provision which allows a source to 

achieve equivalent emission reductions by averaging emissions across coating lines or averaging 

emissions from different coating limits (e.g., topcoat and primer) within a coating line. Crossline averaging provisions may also include the deficiencies described above under AECPS, but 

it is discussed separately in this document because of the allowance for daily weighted 

averaging. 

Unapprovable provision: 

The requirements of Section XXXX shall not apply to any coating line or lines which use 

cross-line averag2Lng as a method of compliance. The method must be approved by the 

APCO and satisfy the following requirements: 

1. Emissions of VOCS, on a daily weighted average, shall be no greater than that amount 

which would result if the affected coating line or lines complied with all applicable requirements 

of this rule ... 
(This example contains only a portion of the actual requirements. Additional requirements such 

as recordkeeping, a complete list of coatings and coating lines, limitations on sources of credit, 

etc., are not included with this example.) 

This language is unapprovable because the provision might hinder EPA's effort to determine 

compliance. The APCO (or director's) discretion could be construed to give the APCO the sole 

authority to approve these provisions independent of the SIP process. Please see the director's 

discretion section of this document for further information. The provision is not consistent with 

the ETPS requirements, and it lacks enforceable criteria and test methods for an inspector to 

determine compliance. 

Although cross-line averaging is generally unacceptable, it may be approved for sources as 

described under Example #2. An EPA accepted emissions averaging method would be to allow 

compliance using a daily weighted average, which allows a source to average emissions on a 

daily basis, if the averaging is accomplished within the same coating line and within the same 

coating category. 

5 

 Approvable provision using a daily weighted average. 

The requirements of Section XXXX shall not apply to any 

coating line which complies with the following requirements: 

1. Emissions of VoCs, determined using a daily weighted average, shall not be greater than 

that amount which would result if the coating line complied with the requirements of 

this rule. 

2. In order for two or more coatings to qualify for inclusion in a daily weighted average calculation, the coatings 
must be used on the same coating line and/or operation, the 

coatings must be regulated under the same emission limit (e.g., both at 3.5 lbs of VOC/gal less 

water and exempt compounds), and the coatings must be applied on the same 

day. 

3. Calculations and test methods for determining compliance are described under Section 

XXXX ... 

(This example contains only a portion of the actual requirements. Additional requirements such 

as recordkeeping, a complete list of coatings and coating lines, limitations on sources of credit, 

etc., are not included with this example.) 

4. Variances. The granting of a variance (aka, variance order, waiver, or conditional 

permit) by a district or state does not permanently change or amend the underlying SIP 

requirement. The variance have in the past deferred the final compliance date (with respect to 

state or local rules) for an individual source or temporarily changed the regulation as it applies to 

an individual source. 

To protect a source from a potential federal enforcement action, the variance must be submitted 

by the state to EPA as a sourcespecific SIP revision and approved by EPA as part of the applicable SIP. All SIP submissions seeking approval of a variance(s) must be accompanied by 

documentation sufficient to clearly show that the operation of the source under the terms of the 

variance will not interfere with attainment and maintenance of the relevant national ambient air 

quality standard. A variance ailowing an increase in emissions of any nonattainment pollutant or 

precursor is not approvable, unless the variance includes offsetting emission reductions which 

result in no net increase in emissions of the pollutant(s). 

For additional discussion on variances, see the September 14, 1989 letter, "Variances and Other 

Hearing Board Orders as SIP Revisions or Delayed Compliance Orders Under Federal Law," 

sent by James D. Boyd, Executive Officer of the California Air Resources Boardi to all Air 

Pollution Control Officers. 
6 

 Capture Efficiency 

Capture efficiency is a measure of the percentage of volatile organic compounds (VOC) 

delivered to a control device. Rules are often developed which specify the destruction efficiency 

from control devices but do not specify what percentage of the total VOCs involved are actually 

delivered to the device. For example, if a control device is limited in a rule to controlling 90% 

of the VOC delivered to it, but only 50% of the VoCs are delivered, then the overall capture and 

destruction efficiency would be only 45% (90% X 50%), and 55% of the VOC would be 

escaping. Thus, the specification of both the capture efficiency and the control device efficiency 

is critical to the stringency of rules that regulate VOCs through the use of add-on control 

equipment. 

capture efficiency determinations were emphasized by Appendix D of EPA's Post-87 Policy (52 

FR 45105-019). On August 1, 1990, EPA provided the states and districts with a copy of EPA's 

capture efficiency measurement protocols (dated April 16, 1990) and on August 28, 1990, EPA 

transmitted a model capture efficiency rule. A copy of the model rule can be found in Appendix 

B. The protocols have been tested by EPA in coil coating and graphic arts facilities, but are 

considered to be applicable to most coating and degreasing operations. 

There are three options which the district can use to eliminate capture efficiency deficiencies. 1) 

Adoption of a capture efficiency method using the EPA model method as the recommended option. By doing so, all terms are defined, test schedules can be included (such as annually or after 

a modification), the monitoring parameters are specified, EPA test methods are referenced and 

reporting requirements are defined. The capture efficiency rule can then be referenced in other 

rules. 2) The rule can reference that the EPA capture efficiency method published in 55 FR 

26865, June 29, 1990,.(which is the EPA model method) be used. 3) The district also has the 

option of developing their own test method which must then be approved by EPA. 

The following are actual examples of rule language where control equipment is described. 

Those examples which are unapprovable by the EPA are followed by revisions which would be 

approvable. 

Examples _ 

1. A provision where the capture efficiency is not specified. 
Unapprovable provision: 

"Install and operate an emissions control system which is designed and operated for the 

maximum collection of fugitive emissions from.... materials and has a control device with an 

efficiency of 90% or more and is approved by the Control Officer." . 

7 

 This provision is not approvable for two reasons: 1) the amount of VOC collection is not 

specified or quantified and 2), the provision does not specify the capture efficiency test method 

to be used. (Note: a separate section of this rule defines an EPA approved test method for 

determining the control device efficiency.) 

Approvable.provision: 

"Install and operate an emissions control system which is designed and operated for the 

collection of 85% or more of all VOC emissions from.... materials and has a control device 

with an efficiency of 90% or more. The control system must be approved by the Control 

Officer. The method used to determine the capture efficiency shall be conducted by the 

EPA capture efficiency test method (Rule XXX)." 

As an alternative, the test method in 55 FR 26865, 29 June, 1990 

could be referenced as the capture efficiency test method to use. 

2. A provision where the capture efficiency is given, but the 

test method is not. 

unapprovable provision: 

11... by using an emission control system for reducing emissions of VOC, consisting of 

collection and control devices which are approved by the Executive Officer or his designee 

and which satisfy the following conditions: 

A) The control device shall reduce emissions from an emis- 
sion collection system by at least 95% by weight, and 

B) the owner/operator shall demonstrate that the emission collection system collects at least 

85% by weight of the emissions generated, and 

C) The VOC content.... 11 

In a separate section of this rule relating to test methods, the method for the determination of the 

VOC reduction by the control device was given but the method for determining the amount of 

VOCs captured was not. Thus, the overall control of VOC emissions cannot be determined and 

this provision, while an improvement over Example 1, is not approvable. 

Approvable provision: 

Include in the testmethods section the following: 

"The method used to demonstrate that the emission collection system achieves the liraits 

specified in Subsection X shall be the EPA method cited in 55 FR 26865, June 29, 1990.11 

8 

 An alternative approvable provision would be to reference an EPA approved district method or 

rule for measuring capture efficiency. 

3. Example of an approvable provision in which separate or combined capture and 

control efficiencies are given.

"All open-top vapor degreasers shall be equipped with a freeboard ratio of 0.75 or greater and at 

least one of the following control devices: 
(i) a freeboard chiller such that the coldest point of the chilled air blanket, measured along the 

vertical axis at the center above the solvent cleaner, is 400 F or less, or; 

(ii) a hood or enclosure to collect emissions, including emissions from lip exhausts, vented to a 

control device. The hood or enclosure shall collect and transfer at least 90% of all 

emissions from the degreasing 

unit to the control device. The efficiency of the vapor collection system shall be 

determined by the EPA test method cited in 55 FR 26865, 29 June 1990. The control 

device, such as a carbon adsorber or incinerator, shall be at least 95 efficient in reducing 

emissions vented from the collection system. The efficiency of the control device shall be 

determined using EPA Reference Method 25, or; 

(iii) a capture and control system as described in (ii) above with an overall capture and 

control efficiency of at least 85%." 

This provision is approvable because it addresses both control and capture efficiency and the 

methods to determine them. Part iii sets a limit on the combined system and allows for some 

variation in capture and control efficiencies in order to achieve that limit. 

9 

Compliance Periods / Averaging Times

Emission limitations, compliance test methods, and recordkeeping requirements must be based 

on time periods consistent with the time frame associated with the national ambient air quality 

standard (NAAQS) for the applicable pollutant. For example, exceedence of (or compliance 

with) the NAAQS for ozone is based on one hour ozone levels recorded over a 24 hour period. 

Therefore, voc emission limitations and records relating to usage of materials containing VOC 

need to be kept on no greater than a daily basis. Allowing any of the above to exceed the time 

frameof the shortest applicable NAAQS would hinder efforts to attain 

that NAAQS. 

Compliance test method averaging times may be shorter than the emission limitation or 

recordkeeping time period because of excessive costs involved with extended testing. For 
similar reason@, test methods at artificially high temperatures (compared to curing and setting 

temperatures) are prescribed to assure the completeness of the emission measurement, ih lieu of 

cooler but longer test measurements. Usage records for materials containing VOCs must be kept 

for periods no longer than that of the emission 

limitation. 

When a time period is not specified, either in the limit, in the compliance test, or in the 

recordkeeping, instantaneous and continuous compliance and recordkeeping will be assumed by 

EPA to be required. As an analogy, the 55 mile per hour speed limit is enforced on an 

instantaneous or continuous basis and not as an hourly average because no compliance period is 

stated. 

Under very limited situations of uniform application and production over an extended period of 

time, averaging ti-mes of 24-hours may be recreated after the fact from production run data and 

coating usage data. Production units (and rejects) must be counted on a daily basis and 

documented, and uniform quantities of VOC must be applied to identical production units over 

the extended period of time. 

Emission limitations with extended averaging over longer than 24-hours are permitted, by EPA, 

in rules for VOC under very limited conditions, and only only where daily limits are infeasible. 

(See memorandum from John R. O'Connor, Acting Director, Office of Air Quality Planning and 

Standards, to Air and Waste management and Air management Division Directors, Regions I-X, 

Subject: Averaging Times for Compliance with VOC Emission Limits - SIP Revision Policy, 

January 20, 1984, and at Appendix D of the EPA Emissions Trading Policy Statement.) The 

following conditions apply: 

10 

 (1) real reductions in actual emissions consistent with RACT control levels, reflecting'typical 

(rather than potential or allowable) production rates and operating hours, supported with 

historical data; including limited non-production or equipment down-time credit based on 

historical data; 

(2) averaging over no longer than 30 days; 
(3) demonstration that long term averaging will not jeopardize either ambient standard attainment or reasonable further progress in the area (this must be 

accompanied by a showing that the maximum daily increase in emissions associated with the 

long term averaging which is consistent with the approved ozone SIP for the area); and 

(4) sources in areas lacking approved SIP's and showing measured violations,,cannot be 

considered for long term averages until the SIP has been revised demonstrating that attainment 

and maintenance of RFP (reflecting the maximum daily emiss4@ons from the source with longterm averaging). 

Example

1. Extended averaging time 

Unapprovable Provision 

An alternative control method may be utilized for can end sealing compounds used on cans 

for fatty foods, in lieu of the limits specified in Section (c). 

The utilization of any combination of emission control device, process and can coatings is 

allowed, provided the total emissions of VOCs over any one operating day do not exceed the 

average emissions per operating day (over a specified historical period), that would have 

occurred if can coatings with VOC content equal to the limits specified in Section (c) had been 

used over the historical period, assuming the use of EPA accepted methods. 

In utilizing this interim alternative, emissions may increase up to 110% of the above limit for 

any particular operating day, provided that average emissions over operating d-ays in any 

calendar week do not exceed the specified daily limits. 

This example uses a daily emission limit based on a historical daily average, which is 

acceptable. However, the last paragraph renders this provision unapprovable because it 

allows sources to exceed the daily limit by averaging emissions over a period of a week. 

11 
 Approvable Provision 

An alternative control method may be utilized for can end sealing compounds used on cans 

for fatty foods from January 1, 1986 through July 1, 1987, in lieu of the limits specified in 

Section (c). 

The utilization of any combination of emission control device, process and can coatings is 

allowed, provided the total emissions of VoCs over any one operating day do not exceed the 

average emissions per operating day over the five year period prior to January 1, 1985, that 

would have occurred if can coatings with VOC content equal to the limits specified in section (c) 

had been used over the five year 'period, assuming the use of EPA accepted methods 

This determination must be made over a 24 hour period based 

on actual hours of operation. 

12 

 compliant Coating and Graphic Atts Material Emission Limitation 

Units 

Compliant coating and ink limitations must be at least as stringent as the VOC RACT emission 

rate limits contained in the EPA Control Techniques Guideline (CTG) documents, after any/all 

thinning or dilution with VOC, water, or exempt compounds. To effect this end, the emission 

rate limitations generally must be expressed in units of weight of volatile compounds, less water 

and exempt compounds (i.e., VOC) per unit volume of VOC and solids, (e.g., grams of 

VOC/liter of coating) as applied. Exceptions, additions and alternatives to the general form of 

the emission limitation are discussed below. 

If the rule allows compliance to be demonstrated through emission trades between lines or 

between coatings with different rule limitations, or through the use of add-on controls, then the 

rule must also limit the weight of VOC per unit volume of solids (or weight of VOC per weight 

of solids for graphic arts). Another acceptable alternative would be for the rule to provide for a 

conversion to a solids basis. The EPA's guidance document, Issues Relating to VOC Regulation 
Cutpoints, Deficiencies, and Deviations (Bluebook) provides an example at its Attachment 3. 

An alternative limitation on the VOC content of graphic arts materials, comparable to carbon 

adsorption or incineration, is provided in the CTG as, the solvent portion of the ink may consist 

of no-more than 25 volume percent VOC and no less than 75 percent by volume exempt 

compounds and water. EPA has also approved a generic alternative RACT definition for graphic 

arts, 0.5 pounds of VOC per pound of solids. (See memorandum from Daryl Tyler, 

EPA/OAQPS, to Director, Air Division, Regions I-X, Subject: Alternative Compliance for 

Graphic Arts RACT, September 9, 

1987.) 

EPA cannot approve limitations which do not exclude water and exempt compounds, which are 

on other than an "as applied" basis, or which allow averaging across coating lines, across 

coatings with different limitations, or across add-on control devices, without the inclusion other 

provisions to prevent circumvention or differences due to the averaging of different density 

materials. 

A different equation is sometimes used for coatings which contain zero or sicall amounts of 

solids (clean-up solvents, wash primers, stains, oils, graphic arts fountain solutions, and certain 

adhesives and adhesive primers). In such products, the amount of coating needed to cover a unit 

of surface area does not depend on the solids content, as in other coatings. However, this form 

of limitation is not approvable under EPA policy for low solids coatings. 

13 

 certain multicomponent coatings and nonheatset inks polymerize (form solid materials through 

the crosslinking of molecules) during the curing process. Some of the VOC is retained as solids 

in porous substrates or in the coating. The current Reference Method 24 (RM-24) drives off 

(captures and measures) these VOC's 

prior to the polymerization. 

Currently EPA recommends that RM-24 with minor modifications be used for multi-component 

coatings. (See memorandum from John Seitz, Director, Stationary Source compliance Division, 

to Air Compliance Branch Chief, Regions I-X, Subject: Applicability of Environmental 

Protection Agency (EPA) Method 24 to Multicomponent Coatings, June 11, 1990.) These 
modifications are that (1) all components of the coating are weighed in the proper proportion 

into the analysis container and mixed together just prior to analysis and (2) the mixture is 

allowed to stand for at least 1 hour, but no more than 24 hours, prior to being oven dried at 110 

degrees C for 1 hour. 

EPA recommends that districts add the above language tc adequately measure the VOC in 

multicomponent and any other polymerization reaction coatings and inks. The second step 

merely ensures that the catalytic reaction which must occur between the components of the 

coating has begun or, in some cases, is completed before the coating is heated. 

One District has taken this recommendation one step further and applied it to the form of the 

emission limitation for all coatings and inks which may have components which need to become 

solidified during the curing process. Such general application of the two-step measurement 

process through reference to separate curing and analysis emissions is consistent with EPA 

policy. 

EPA is investigating potential policy changes relating to low solids coatings and reactive 

diluents. However, it would be premature to recommend changes based on some Districts' 

perceived resolution of these issues. 

Examples

1. Calculation of compliant coating emission limits Approvable Provision: 

Compliant coating emission limits shall be expressed in units of grams of VOC per liter of 

coating or ink, less water and exempt compounds, as applied, and shall be calculated by the 

following equation: 

(Ws - Ww - Wec)/(Vm - Vw - Vec) 

14 

 where: 
Ws = weight of volatile compounds evolved analysis, 

in grams 

Ww = weight of water evolved during analysis, in grams 

Wec = weight of exempt compounds evolved during analysis, 

in grams 

weight of volatile compounds evolved analysis, 

in grams 

volume of coating and/or ink, including any thinners 

and diluents applied, in liters 

Vw = volume of water evolved during analysis, in liters 

Vec = volume of exempt compounds evolved during analysis, 

in liters 

2. Calculations for low and zero solids coatings and graphic arts 

materials. 

Unapprovable Provision: 

Calculations for low solids coatings shall be made according 

to the following fomula: 

(Ws - Ww - Wec)/(Vm) 

where: 
Ws = weight of volatile compounds in grams 

Ww = weight of water in grams 

We, = weight of exempt compounds in grams Vm = volume of material in liters. 

Compliant coating emission limits must be expressed in units of grams of VOC per liter of 

coating or ink, less water and exempt compounds, as applied, and may not be calculated by the 

equation above. 

Approvable Provision: 

The equation listed at 1, above is approvable for low solids

coatings. EPA policy does not address zero solids coatings.

15 

 3. Calculation for Reactive Diluent 

Unapprovable Provision 

The amount of reactive diluent (defined such that VOC remaining in the substrate is excluded) 

shall be determined by a test method yet to be developed. 

EPA does not recognize a VOC test method that requires testing of 

coatings, inks, etc. on different substrates. 

Approvable Provision: 

Calculations for reactive diluents shall be made according 

to the following fomula: 

(Ws - ww - w ec)/(Vm - Vw - Vec) 

where: 
W, = weight of volatile comp 

 w 

 w 

 v 

ec 

ec 

weight of volatile compounds evolved during 

curing and analysis, in grams 

weight of water evolved during curing and 

analysis, in grams 

weight of exempt compounds evolved during 

curing and analysis, in grams 

volume of material prior to reaction, in liters 

volume of water evolved during curing and 

analysis, in liters 
volume of exempt compounds evolved during 

curing and analysis, in liters 

Compliant coating emission limits must be expressed in units of grams of VOC per liter of coating 

or ink, less water and exempt compounds, as applied. The Reference Method should describe in 

detail the procedure to be followed. 

16 

Director's Discretion

"Director's Discretion" refers to provisions in rules or regulations which allow a representative of 

a State or local agency to approve alternatives to the basic provisions of-the State or district 

regulation without further regulatory process. When the director exercises his judgement, the 

rule is altered from its adopted, approved form without notification, evaluation, or approval from 

the next levels of government (e.g. when done on a local level, the state and EPA have no voice 

in the approval of 

the alternative). 

EPA cannot approve certain types of director's discretion provisions because, in some cases, 

judgements made under such provisions may alter the stringency of the federally-approved SIP. 

Excess emissions from sources can occur with certain types of director's discretion provisions 

related to test methods, control requirements, exemptions, etc. 

EPA can approve certain types of director's discretion provisions that only involve minor 

changes or adaptations to the basic regulation that do not have the potential to change the stringency of the federally-approved SIP. 

Please refer to other sections in this guidance document regarding specific requirements for test 

methods, alternative controls, recordkeeping, etc. 

Examples
The following are examples of approvable director's discretion 

provisions: - 

1. Inclusion of replicable procedures to determine equivalency of 

alternative controls. 

A person shall not refinish Group I vehicles, their parts and components, or Group II vehicles 

and mobile equipment where color match is required, using any coating with a VOC content in 

excess of the following limits, expressed as grams of VOC per liter (or pounds per gallon) of 

coating applied, excluding water and exempt solvents, unless emissions to the atmosphere are 

controlled to an equivalent level by air pollution abatement equipment with an overall control 

efficiency (capture and control) of at least 85% and which has been approved in writing by the 

APCO: (This assumes that a test method is specified in the rule to calculate the 85% and 

equivalency) . 

17 

 In this example, test methods provide the replicable procedure to calculate the 85% efficiency. 

The rule must also specify the method used to determine equivalency. Any inspector visiting the 

facility should be able to use the test methods specified in the rule to determine compliance. 

2. Inclusion of replicable procedures by which monitoring requirements may be changed.

The monitoring schedule of paragraphs 1 to 3 of this section 

may be modified as follows: 

(a) After completion of the required annual and quarterly inspections for a period of at least 

two years, the operator of a refinery may request in writing to the Air Pollution Control Board 

that the monitoring schedule be revised based on the percent of valves leaking. The percent of 

valves leaking shall be determined by div@Lding the sum of valves leaking during current 

monitoring and valves for which repair has been delayed, by the total number of valves subject 

to the requirements. This request shall include all data that have been developed to justify the 

following modifications in the monitoring schedule: 

(i) after two consecutive quarterly leak detection periods with the percent of valves leaking 

equal to or less than 2.0%, an owner or operator may begin to skip one of the quarterly leak 
detection periods for the valves in gas/vapor 

and light liquid service; 

(ii) after five consecutive quarterly leak detection periods with the percent of valves 

leaking equal to or less than 2.0%, an owner or operator may begin to skip three of the quarterly 

leak detection periods for the valves in gas/vapor and light liquid service. 

(b) If the Executive Officer determines that there is an excessive number of leaks in any 

given process area, he may require an increase in the frequency of monitoring for that process 

area of the refinery. 

(Test methods are specified in a separate paragraph of this rule.) 

The above example provides replicable procedures to be used by the Air Pollution Control Board 

to make the determination that the monitoring schedule be revised. It also provides replicable 

procedures for the Executive Officer to make the determination that an increase in the frequency 

of monitoring is needed. 

3. Inclusion of language to preserve enforceability of federally 

approved limits. 

For purposes of federal enforceability of this article, the EPA is not subject to approval 

determinations made by the Executive Officer under Sections XX and XX. Upon the request of 

a person who has been granted an exemption under Section XX or XX, an exemption meeting 

the requirements of the Clean Air Act shall be submitted by the Executive Of18 

 ficer to the Envirormental Protection Agency for inclusion in the applicable implementation 

plan approved or promulgated by the EPA pursuant to Section 110 of the Clean Air Act, 42 

U.S.C. Section 7410. 

In this example, found in the California State Consumer Products rule, EPA is not bound by any 

approval determinations made by the Executive Officer, unless and until EPA approves the 

determination as part of the SIP. 
The following are examples of unapprovable director's discretion 

provisions along with their corrections:

1. Discretion in exemptions and recordkeeping requirements: 

Unapprovable provision: 

The requirements of this Section shall not apply to any person who complies with an 

alternate recordkeeping plan that provides for an enforceable daily record which has been 

approved by the APCO in writing. 

This example has the potential to allow an APCO to exempt a source on the basis of an alternate 

recordkeeping plan. The APCO has the ability to approve any type of daily recordkeeping in order to exempt the source from the requirements of the rule. 

Approvable provision: 

The requirements of this Section shall not apply to any person who complies with an 

alternative recordkeeping plan, provided that the plan has been submitted to and approved 

by . ARB and EPA. 

In order to be approvable, without the submission of a source specific SIP revision, the rule must 

state specifically what type of alternative recordkeeping will be allowed. If the type of 

recordkeeping is not stated in the rule, EPA would require a source specific SIP revision to be 

submitted. The rule also must specify that the application of director's discretion would have no 

impact on the federally-approved SIP. 

2. Discretion in methods of compliance: 

Unapprovable provision: 

For cold solvent cleaning, one of the following control devices (must be used): 

(a) a freeboard such that the freeboard ratio is equal to or greater than 0.75, 

(b) a water cover if the solvent is insoluble in heavier than water, or 
19 

 (c) any other system of equivalent control approved by the 

Executive Officer. 

The above example allows a cold solvent cleaning device to be in compliance if it has one of the 

control systems described in (a) or (b), or has a system considered equivalent by the EO. The 

rule does not state what types of other equivalent control devices could be used or provide 

replicable criteria for choosing 

an equivalent control device. 

Approvabl,e provision: 

For cold solvent cleaning, one of the following control 

devices (must be used): 

(a) a freeboard such that the freeboard ratio is equal to or 

greater than 0.75, or 

(b) a water cover if the solvent is insoluble in heavier 

than water, or 

(c) a hood or enclosure to collect all emissions, including 

emissions from lip exhausts, vented to a control device. 

In order to be approvable, the rule should specify all the control systems, as shown above, and 

include applicable test methods and capture/control efficiencies. If the State/District wishes to 

provide for equivalent means of control, then a description of the equivalent control system 

being proposed must be submitted to ARB and EPA for approval as part of the SIP. An example 

of that type of language is as follows: 

(d) any other system of equivalent control approved by the Executive Officer and submitted 

to and approved by ARB and EPA. 
3. Discretion in emission limits: 

Unapprovable provision: 

Within seven months of each compliance date specified by Subsection (d)(5)(ii), the Air 

Pollution Control Officer (APCO) shall evaluate the VOC reduction efficiency actually 

achieved in practice by equipment used to meet the requirements of Subsection (d)(5)(ii). If 

the required VOC reduction efficiency cannot be met on an ongoing basis, after all 

reasonable efforts to achieve compliance have been made, the APCO s-hall advise the Air 

Pollution Control Board and make a recommendation to revise this rule to reflect the 

maximum VOC reduction efficiency that can reasonably be met on an ongoing basis. In the 

case of such inability to meet the required VOC reduction efficiency, the requirements of 

Subsection (d)(5)(ii) shall be deemed to have been met for the period from the date of final 

compliance specified in Subsection (d)(5)(ii) until such time as the Air Pollution Control 

Board acts on the recommendation of the APCO.

20 

 The above example allows the Air Pollution Control Officer the flexibility to alter an emission 

limit for a particular source and find that source in compliance because it cannot meet the requirements of Subsection (d)(5)(ii). This example also provides for the wholesale relaxation of 

the rule if a source cannot comply with it. The term "reasonable efforts" must also be defined in 

the rule. 

Approvable Provision: 

Within seven months of each compliance date specified by Subsection (d)(5)(ii), the Air 

Pollution Control Officer shall evaluate the VOC reduction efficiency actually achieved in 

practice by equipment used to meet the requirements of Subsection (d)(5)(ii). If the required 

VOC reduction efficiency cannot be met on an ongoing basis, after all reasonable efforts to 

achieve compliance have beefi made, the so@rce shall apply to the local District for an 

alternate emission control plan (AECP). Upon approval of the AECP by the APCO, the 

AECP shall be submitted to and approved by ARB and EPA. 

If the source is unable to continually meet the required VOC reduction efficiency stated in the 

rule, then an official change, in the form of a source specific SIP revision, is required. If a 

source specific SIP revision were not submitted, the APCO would have the authority to relax the 

requirements of an officially adopted and approved rule. For additional information, see the 

Section on Alternate Controls. 
4. Discretion in test methods: 

Unapprovable provision: 

The purpose of this rule is to determine essentially all the volatile organic compounds 

present in the coating as used. The volatile organic content of the coating material per 

volume of coating material, less water, shall be determined by using EPA Reference Method 

24 or by any other method approved by the Executive Officer. 

The above example allows an unspecified test method to be used to determine compliance. This 

provision could allow a district to use a test method which has not yet undergone EPA review. If 

the Executive Officer approved another test method, EPA could be bound by the Executive 

officer's approval even if EPA disagreed with the Exequtive Officer's approval. Since approval 

of other test methods constitute a modification of the SIP, EPA must be kept in the approval 

process. (A discussion of other test method requirements can be found in the Test Methods 

section of this document.) 

21 

 A test method not stated in the rule, but selected by the Executive officer, could potentially 

allow a test method considered to be inappropriate by EPA to be used for compliance 

determinations. 

Approvable provision: 

The purpose of this rule is to determine essentially all the volatile organic compounds 

present in the coating as used. The volatile organic content of the coating material per 

volume of coating material, less water and exempt compounds, shall be determined by using 

EPA Reference Method 24. The use of an alternative test method may be approved by the 

APCO, provided the alternative is submitted to EPA as a source specific SIP revision. 

The above example states specifically which test method will be used to determine the amount of 

volatile organic compounds present in the coating as used. Since the method is listed, there is no 

question as to which method can be used to determine compliance. (This example is also 

discussed in the Section on Test Methods.) 
5. specification of application methods with director's discretion. 

Unapprovable provision: 

"Application Methods. Effective twelve months from the date of adoption for all coatings, a 

person shall not apply any coating to any Group I or II vehicles or mobile equipment or their 

parts and components unless one of the following methods is used: 

(1) Electrostatic application equipment, operated in accordance with the manufacturer's 

recommendations; 

(2) High Volume Low Pressure (HVLP) spray equipment, operated in accordance with the 

manufacturer's recommendations; 

(3) Any other coating application method which has been demonstrated to the satisfaction of 

the Executive Officer and for which written approval of the Executive Officer has been 

obtained.-' 

The problem with this provision is in section (3). If this provision were approved by EPA, EPA 

might be subject to an equipment approval decision made by the Executive Officer even if EPA 

did not agree with the Executive Officer's decision. Thus, the provision is unapprovable because 

of its potential to modify the SIP without prior EPA approval. 

Approvable provisions: 

There are two possible fixes for this unapprovable provision: 

22 

 1. Remove section (3) and amend the rule as new high transfer efficiency processes are 
presented and verified to the district. 

2. Require the source to get ARB and EPA approval as well as the Executive officer 

approval in section (3). Thus, section (3) might be written as follows: 

(3) Any other coating application equipment which has been demonstrated to the satisfaction 

of the Executive Officer and the Administrator of EPA, and approved by the Executive Officer, 

the ARB, and the EPA as a SIP revision. 

23 

 UnanDrovable provision: 

Effective 60 days after adoption, a person shall not operate any perchloroethylene dry 

cleaning facility unless any solvent liquid or solvent vapor leaks are repaired immediately. 

The above provision is unapprovable because it does not require the source to maintain records 

regarding leaking components and repair and maintenance of leaks. 

Approvable provision: 

Effective 60 days after adoption, a person shall not operate any perchloroethylene dry 

cleaning facility unless any solvent liquid or solvent vapor leaks are repaired immediately. 

A daily inspection log shall be maintained. This log shall 

include the following: 

a. Leak(s) found - liquid or vapor - date and time; 
b. Identification of leaking component; and 

C. Leak(s) repaired - date and time. 

The above provision is approvable because it requires the source to maintain specific records so 

that identification and the repair of leaks can be verified by the daily maintenance records. 

2. Exemptions. 

Unapprovable provision: 

The Control Officer shall exempt the following facilities from the provisions of Section X, 

upon receipt of a petition and verification of qualification. The owner or operator of an 

exempt facility shall petition annually for renewal of the exemption. 

a. Facilities using less than 1200 liters (320 gallons) per year of perchloroethylene. 

In the above section recordkeeping requirements are needed to record the usage of 

perchloroethylene in order for the source to prove eligibility for the exemption specified above. 

Approvable provision: 

XX. Recordkeeping 

1. Any person subject to this Rule shall maintain records on a daily basis showing the 

amount of perchloroethylene consumed in the dry cleaning process. 

25 

 2. Such records shall be retained and available for inspection for the previous 24 month 

period. 

3. A daily inspection log shall be maintained. 
In the above section daily recordkeeping might be needed for 

other purposes besides proving the exemption. 

For further guidance, districts can refer to EPA's guidance document entitled "Recordkeeping 

Guidance Document for Surface Coating operations and the Graphic Arts Industry." 

2 6 

 Una-nrovable provision: 

Effective 60 days after adoption, a person shall not operate any perchloroethylene dry 

cleaning facility unless any solvent liquid or solvent vapor leaks are repaired immediately. 

The above provision is unapprovable because it does not require the source to maintain records 

regarding leaking components and repair and maintenance of leaks. 

Approvable provision: 

Effective 60 days after adoption, a person shall not operate any perchloroethylene dry 

cleaning facility unless any solvent liquid or solvent vapor leaks are repaired immediately. 

A daily inspection log shall be maintained. This log shall 

include the following: 

a. Leak(s) found - liquid or vapor - date and time; 

b. Identification of leaking component; and 

C. Leak(s) repaired - date and time. 

The above provision is approvable because it requires the source to maintain specific records so 
that identification and the repair of leaks can be verified by the daily maintenance records. 

2. Exemptions. 

Unapprovable provision: 

The Control officer shall exempt the following facilities from the provisions of Section X, 

upon receipt of a petition and verification of qualification. The owner or operator of an 

exempt facility shall petition annually for renewal of the exemption. 

a. Facilities using less than 1200 liters (320 gallons) per year of perchloroethylene. 

In the above section recordkeeping requirements are needed to record the usage of 

perchloroethylene in order for the source to prove eligibility for the exemption specified above. 

Approvable provision: 

XX. Recordkeeping 

1. Any person subject to this Rule shall maintain records on a daily basis showing the 

amount of perchloroethylene consumed in the dry cleaning process. 

25 

 source Applicability and Exemptions

Rules often contain provisions which only apply to larger sources or which exempt smaller 

sources. Such provisions must be consistent with Control Techniques Guideline (CTG) 

requirements and any EPA policy requirements. Appendix A lists the CTGs issued by EPA and 

a more detailed summary of each CTG's requirements can be found in Attachment 1 of EPA's 

guidance document, Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations 

(Bluebook). Applicability requirements or exemptions in district rules must be consistent withCTG requirements and EPA policy requirements. 
Applicability requirements and exemption allowances depend upon the source category. This 

section is not meant to provide a complete description of what must be covered by each sour6e 

category. Instead, it will present examples of both unapprovable and approvable provisions and 

a discussion of the issues surrounding the examples. 

Examples

1. CTG sources exempted from RACT requirements. 

Unapprovable provision: 

The objective of this rule is to limit emissions'of vocs from organic liquid loading facilities. 

For the purposes of this rule, organic liquid loading facilities are those facilities which load 

more than 20,000 gallons of organic liquids with a true vapor pressure of at least 1.5 psia at 

loading conditions in any one day. 

The above provision indicates that the rule applies only to organic liquid loading facilities that 

load more than 20,000 gallons of organic liquids per day, defined as bulk terminals per EPA's 

definition of such facilities. However, EPA also requires control of emissions at bulk plants, 

defined as those facilities which load less than or equal to 20,000 gallons of organic liquids per 

day. As specified in EPA's CTG for Bulk Gasoline Plants, EPA-450/2-77-035, EPA will allow 

an exemption for facilities which load less than 4,000 gallons of organic liquids per day from 

emission control requirements. Except for this throughput exemption, however, all other 

existing bulk plant facilities must employ emission controls per EPA's bulk plant CTG. The 

above provision can be made approvable by additionally requiring that facilities which load 

between 4,000 and 20,000 gallons per day of organic liquids be subject to the requirements as 

listed in the Bulk Plant CTG. 

27 

 3. Exemption not consistent with EPA policy. 

Unapprovable provision: 

(j) Exemptions 

(1) The provisions of subparagraph (b)(1) of this rule 

shall not apply to coatings with separate formulations that are used in volumes of less than 

20 gallons per year provided that the total usage by a facility is less than 200 gallons of such 

formulations applied annually. 
EPA policy (G.T. Helms memo titled "Exemption for Low-Use Coatings, 10 August 1990) 

allows an exemption of up to 55'gallons of such formulations per year per facility, irrespective of 

the amount allowed for each separate formulation. The above provision effectively exempts up 

to 145 gallons more of separate coating formulations per facility per year than the requirements 

of EPA's policy. The provision would be approvable if the 200 gallons total annual limit per 

facility were changed to 55 gallons. 

Approvable provison: 

(j) Exemptions 

(1) The provisions of subparagraph (b)(1) of this rule 

shall not apply to coatings with separate formulations that are used in volumes of less than 

20 gallons per year provided that the total by a facility is less than 55 gallons of such 

formulations applied annually; or 

(1) The provisions of subparagraph (b)(1) of this rule shall not apply to coatings with 

separate formulations provided that the total by a facility is less than 55 gallons of such 

formulations applied annually. 

29 

Test Methods

EPA's guidance document, ISSUES RELATING TO VOC REGULATION CUT . POINTS, 

DEFICIENCIES, AND DEVIATIONS, Clarification to Appendix D of November 24, 1987 

Federal Register (Bluebook) states that the most current VOC EPA test methods should be used 

and that all test methods must be specified in the SIP. The Bluebook contains a list of 

recommended test methods and procedures that can be used for Group I, II and III CTG 

categories. 

In general, district rules should specify EPA Reference Methods for determining compliance 

wherever a test method is required. 

These methods are listed in 
Reference ethods.' In some Method 

exists, other EPA-approved test methods nay be used. EPA approval of test methods is critical 

to ensure consistency and accuracy in compliance determinations. In no instance will a test 

method be approved for use in a SIP unless it has been reviewed and approved by EPA. A list of 

EPA-approved test methods developed by the American Society for Testing and Materials 

(ASTM) is given at the end of 40 CFR Part 60 under the heading, Material Approved for 

Incorporation by Reference. Some test methods developed by the California Air Resources 

Board (CARB) have also been approved by EPA. 

Several districts within California have chosen to develop and use their own test methods for 

determining compliance, claiming that their methods are either cheaper, more efficient or more 

stringent than comparable EPA Reference Methods. EPA recognizes that some district test 

methods may, in fact, be an improvement over EPA methods. However, all test methods must 

still be evaluated and approved by EPA before the rule containing the test method can be 

approved into the SIP. 

Several examples are given below of provisions taken from actual district rules which are not 

approvable by EPA because they fail to meet EPA requirements regarding test methods. 

Following each example is a discussion of the problem and suggested a approvable provision. 

Examples

1. No test-method given. 

Unapprovable provision: 

Gas Ti @t - is defined as a concentration of VOC, measured 1 cm from any source and 

expressed as methane, less than or equal to 10,000 ppm above background. 

3 0 

 While defined correctly, this provision is unapprovable because it does not specify a test method 

with which to measure the VOC concentration above background. This provision can be made 

approvable by including an EPA approved test method for making the 

compliance determination. 
Approvable provision: 

Gas Tiqht - is defined as a concentration of VOC, measured 1 cm from any source and 

expressed as methane, less than or equal to 10,000 ppm above background, as determined by 

EPA Reference Method 21. 

2. Use of a non EPA-approved test method. 

Unapprovable provision: 

For purposes of applicability, the true vapor pressure shall be determined by ASTM Method 

D323-89 - Vapor Pressure of Petroleum Products (Reid Method). 

ASTM test methods are identified by a method number preceded by a letter of the alphabet (in 

this case D323) followed by a two digit number indicating the date the test method was 

developed or last reviewed". The test method referenced in the above provision was last 

reviewed in 1989. A check of the list of EPA approved ASTM methods at the end of 40 CFR 

Part 60, however, indicates that only an earlier version of ASTM method D323 has been 

approved by EPA: D323-82. Without review and approval by EPA of the 1989 version of 

ASTM D323, the above provision is unapprovable. This provision can be made approvable by 

referencing the EPA approved version of the ASTM method instead of the unapproved revised 

version of the method, or by submitting the 1989 version of the ASTM method with the revised 

rule for EPA review and approval into the SIP. 

Approvable provision: 

For purposes of applicability, the true vapor pressure shall be deteridined by ASTM Method 

D323-82 - Vapor Pressure of Petroleum Products (Reid Method). 

If a district chooses to use a non EPA-approved test method, a copy of the method should be sent 

to EPA for review along with a copy of the rule to which it applies. Since the review process for 

a test method will likely take longer than that for a rule, the method and corresponding rule 

should be sent to EPA at the earliest possible date. The district should include documenta--------

------------ 

2. ASTM reviews all methods periodically and will change the date of the method to reflect 
the latest review, whether or not the method has been-altered. 

3 1 

 tion demonstrating that the method is accurate, provides repeatable results, is appropriate for the 

rule provision in question, and, if applicable, produces results consistent and equivalent to those 

obtained with any existing EPA Reference Method that it is replacing. Copies of test methods 

and documentation should be sent to: 

Chief, State Implementation Plans Section 

U.S. EPA, Region 9 

75 Hawthorne Street (A-2-3) 

San Francisco, CA 94105 

3. More than one test method listed. 

Unapprovable provision: 

All gasoline delivery vehicle tanks shall be maintained in a gas-tight condition. The gastight condition of the tanks shall be determined by either EPA Reference Method 27 or ARB 

Method 2-5. 

In some cases a District may choose to list more than one EPAapproved test method for 

determining compliance. Even though both test methods listed above are EPA-approved, they 

may not produce the same results. Thus, it is possible that one method may indicate a violation 

while the other indicates compliance with the rule provisions. To avoid such discrepancies, the 

district should only reference one of the two methods in the rule. Since both methods have been 

approved, either would be acceptable for determining compliance. In the event that a District 

insists on listing both methods, the rule must also state that a violation determined by either test 

method shall constitute a violation of the rule. . 

Approvable provision: 

All gasoline delivery vehicle tanks shall be maintained in a vapor-tight condition. The gas-
tight condition of the tanks shall be determined by either EPA Reference Method 27 or ARB 

Method 2-5. A violation determined by either tes . t method shall constitute a violation of 

the rule. 

32 

Transfer Efficiency (TE)

Transfer efficiency requirements are often found in coating 

regulations and can be defined as the following ratio: 

Amount of solids adhering to substrate 

TE = -------------------------------------- 

Total amount of solids used 

As the TE for a coating operation increases, the total amount of coating used should decrease, 

and thus, less volatile organic compounds (VOCS) should be emitted into the atmosphere. This 

is a very simple concept; however, the implementation and measurement of TE requirements has 

lead to many problematic situations. 

EPA's guidance document, Issues Relating to VOC Regulation Cutpoints, Deficiencies, and 

Deviations (a.k.a. the "Blu--book"), contains a discussion on TE. Most of the TE issues found in 

the Bluebook concern district rules which allowed sources to generate emissions credits by 

changing application equipment. In the past, TE emissions credits were used to bring sources 

into compliance. Unfortunately, the credits were often based upon invalid baseline TE's and 

table value TE's (e.g., NSPS table values) which were not appropriate. In order to receive credit 

for using a more transfer efficient process, a source must use the correct baseline TE and a valid 

test method to determine the actual TE for the more transfer efficient process, and the criteria for 

determining the baseline and test method must be 

specified by the rule. 

The main problem in determining the actual TE for a coating rule is that there are currently no 

EPA approved TE test methods except for Automobile and Light-Duty Truck 
Manufacturin g facilities. TE Test methods must be custom designed for the 

situation that is being tested and must consider all the parameters of the operation (e.g., substrate 

size, substrate shape, application equipment, etc.). A change in any of the operation's parameters 

can invalidate the TE determined by a method. Past efforts have attempted to assign specific TE 

percentages to different types of application equipment based upon test results performed on 

panels. However, results from such tests could rarely be used due to the vast variety of shapes, 

sizes and other operating conditions found from facility to facility. - 

Because of all the problems associated with TE requirements and developing TE test methods, 

the California Technical Review Group (TRG) created a sub-committee to study the problem and 

recommend some solutions. Based upon the TRG recommendation (January 30, 1989 letter 

from Eric P. Skelton to APCO's),,many recent regulations simply specify the type of application 

equipment that must 

33 

 be used and no longer require a TE percentage. However, there is 

often still a TE percentage requirement for equipment other than 

the specified equipment. 

The following examples of language extracted from both actual and proposed regulations are 

directly associated with some of the issues discussed above. Each of the examples are followed 

by a brief discussion of problems found with the example and potential remedies. (It should also 

be noted that the invalid TE credits were generated for rules which were silent concerning TE 

requirements, and thus, there are no such examples presented below.) 

Example

1. Requiring that unspecified application equipment is 65% transfer efficient based upon 

approved procedures. 

Unapprovable provision: 

"Transfer Efficiency 
On or after January 1, 1991, a person or facility shall not apply coatings unless the coating is 

applied with properly operating equipment, according to operating procedure specified by 

the equipment manufacturer or the Deputy Executive Officer/Operations, and by the use of 

one of the following methods: 

(A) Electrostatic application, or 

(B) Flow coater, or 

(C) Roll coater, or 

(D) Dip coater, or 

(E) High-Volume Low-Pressure (HVLP) spray, or 

(F) Hand Application Methods, or 

(G) Such other.alternative application methods as are demonstrated to the Deputy 

ExecL,-tive Officer/operations, using District approved procedures to be capable of achieving at least 65 percent transfer efficiency and for which written approval of the Deputy 

Executive Officer/Operations has been obtained." 

This provision is unapprovable for the following reasons: 

(1) It allows Executive Officer approval without EPA approval. 

(2) It contains a 65% requirement based upon district procedures which have never been 

evaluated or approved by EPA. 

Approvable provision(s): 

There are three possible fixes for this provision: - 

1. Remove section (G) and amend the rule as new high transfer efficiency processes are 

presented and verified to the district. 

34 

 2. Require the source to get EPA approval as well as the 

Deputy Executive Officer/Operations, approval in section 

(G).
3. Include a reference to an EPA approvable district test method. Thus, section (G) might 

include the following language: 11... Such other alternative application methods which have 

been demonstrated to-be achieving at least 65 percent transfer efficiency using District 

Procedure XX.I. 

With this language, the district mus@.also submit District Procedure XX and the approvability 

of this portion of the rule would depend on EPA's evaluation of District Procedure XX. 

35 

VOC DefinitiOn

EPA's guidance document, Issues Relating to VOC Regulation Cutpoints, Deficiencies, and 

Deviations (a.k.a. the "Bluebook") provides a model VOC definition. Since the publication of 

the Bluebook (May 25, 1988), four additional compounds have been added to the list of exempt 

compounds. Thus, the following compounds are considered non-reactive by EPA and are not 

controlled as VOCS: 

-1. Methan@ 

'2. Ethane' 

3. Methyl Chloroform (111,1-Trichlororethane) 

4. Trichlorotrifluoroethane (CFC-113) 

5. Methylene Chloride 

6. Trichlorofluoromethane (CFC-11) 

7. Dichlorodifluoromethane (CFC-lz) 

-8. Chlorodifluororethane (CFC-22) 

9. Trifluoromethane (CFC-23) 

10. Dichlorotetrafluoroethane (CF-114) 

11. Chloropentafluoroethane (CFC-115) 

12. Dichlorotrifluoroethane (HCFC-123) 

13. Tetrafluoroethane (HFC-134a) 

14. Dichlorofluoroethane (HCFC-141b) 

15. Chlorodifluoroethane (HCFC-142b) 

The last four compounds (12-15) in the above list have been added to the list since the 

publication of the Blue Book. Many districts have exempted these compounds in their definition 

of VOCS. However, some distriqts want to control compounds that are considered exempt or 

non-reactive by EPA and have not specfically exempted all the above compounds from their 
VOC definition. EPA finds this more stringent approach acceptable as long as the districts do 

not claim the control of these compounds as emission reductions in their Ozone State 

Implementation Plans (SIP), as credits under the Emissions Trading Policy, or for determining 

compliance with emission limits. 

-------------------- 

3. The California Air Resources Board considers ethane as a reactive VOC and will not 

approve rules which exempt ethane. EPA will accept a VOC definition which does not exempt 

ethane if emission reduction credits associated with the control of ethane are not claimed-in the 

district's ozone SIP. 

36 

Examples

1. Examples of VOC definitions with specified exempt compounds. 

Approvable definition: 

Any organic compound which participates in atmospheric photochemical reactions. This 

includes any organic compound other than the following compounds: methane, ethane, 

methylene chloride, methyl chloroform (1,1,1trichloroethane), CFC-113 

(trichlorotrifluoroethane), CFC-11 (trichlorofluoromethane), CFC-12 

(dichlorodifluoromethane), CFC-22 (chlorodifluoromethane), CFC-23 (trifluoromethane), 

CFC-114 (dichlorotetrafluoroethane), CFC-115 (chloropentafluoroethane), HCFC-123 

(dichlorotrifluoroethane), HFC134a (tetrafluoroethane), HCFC-141b (dichlorofluoroethane), 

and HCFC-142b (chlorodifluoroethane). These compounds have been determined to have 

negligible photochemical reactivity. For purposes of determining compliance with emission 

limits, VOC will be measured by the approved test methods. Where such a method also 

inadvertently measures compounds with negligible photochemical reactivity, an owner or 

operator may exclude these negligibly reactive compounds when determining compliance 

with an emissions standard. 

This definition is based upon the model definition found in EPA's 

Bluebook. 
Unapprovable definition: 

"Volatile Organic Compound: Any organic compound (excluding methane, carbon 

monoxide, carbon dioxide, carbonic acid A metallic carbides or carbonates and ammonium 

carbonate) which would be emitted during use, application, curing or drying of a solvent or 

surface coating. For the purpose of calculating the VOC content of a coating, any water or 

the following non-precursor organic compounds shall not be considered to be part of the 

coating: 

methylene chloride 

1,1,1-trichloroethane 

trichlorofluoromethane (CFC-11)

dichlorodifluoromethane (CFC-12)

trichlorotrifluoroethane (CFC-113)

dichlorotetrafluoroethane (CFC-114)

chloropentafluoroethane (CFC-115)"

-------------------- 

4. These compounds are not specifically exempted by EPA as they are considered inorganic 

compounds; however, district VOC definitions which specifically exempt these compounds will 

not be unapprovable based upon this exemption. 

37 

 This definition is unapprovable because is not consistent with EPA's VOC definition and list of 

non-'reactive compounds; however, it would be approvable if the district did not claim any 

emission reduction credits resulting from the decreased use of exempt compounds which are not 

listed above, but are considered exempt by EPA. 

Approvable definition: 

Volatile Organic Compound: Any organic compound which would be emitted during use, 

application, curing or drying of a solvent or surface coating. For the purpose of calculating 

the VOC content of a coating, any water or the following non-precursor organic compounds 

shall not be considered to be part of the coating. However, the District will not claim 
emission reduction credits from the control of any compound determined to be negligably 

phutochemically reactive by EPA: 

methylene chloride 

1,1,1-trichloroethane 

trichlorofluoromethane (CFC-11)

dichlorodifluoromethane (CFC-12) 

trichlorotrifluoroethane (CFC-113)

dichlorotetrafluoroethane (CFC-114) 

chloropentafluoroethane (CFC-115) 

2. VOC definition exempting compounds not specifically exempted 

per EPA's VOC definition. 

Unapprovable provision: 

"PHOTOCHEMICALLY REACTIVE SOLVENT means any solvent with an aggregate or 

more than 20 percent of its total volume composed of the chemical compounds classified 

below or which exceeds any of the following individual percentage composition limitations, 

referred to the total volume of solvent: 

(a) A combination of hydrocarbons, alcohols, aldehydes, ethers esters or ketones having an 

olefinic or cycloolefinic type of unsaturation except 

perchloroethylene: 5 percent; 

(b) A combination of aromatic compounds with eight or more carbon atoms to the molecule 

except ethylbenzene, 

methyl benzoate and phenyl acetate: 8 percent; 

(c) A combination of ethylbenzene, ketones having branched hydrocarbon structures, 

trichloroethylene or toluene: 

20 percent. 

Whenever any organic solvent or any constituent of an organic solvent may be classified 

from its chemical structure into more than one of the above groups of organic compounds, it 

shall be considered as a member of the most reactive chemical group, that is, that group 
having the least allowable percent of the total volume of solvents." 

38 

 The exemption of perchloroethylene as a photochemically reactive solvent is inconsistent with 

EPA's VOC definition. Furthermore, this definition potentially allows a source to dilute a 

solvent to a point where the solvent may no longer be considered photochemically reactive. 

There is no easy way to fix this definition. EPA would recommend that this definition be 

replaced with one of the VOC definitions found in Example 1 above. 

3. VOC definition based upon vapor pressure. 

Unapprovable definition: 

Volatile Organic Compound (VOC). VOC means any organic compound (excluding 

methane, carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates 

and ammonium carbonate) that has a vapor pressure greater than 0.1 mm of Hg at standard 

conditions. 

EPA's Bluebook states specifically that use of a vapor pressure cutoff to define VOC is inconsistent 

with EPA reactivity policy. Such a definition would exempt compounds of low volatility which, 

under certain conditions, would volatilize and, therefore, would participate in photochemical 

reactions. Again, EPA would recommend that this definition be replaced with one of the VOC 

definitions found in Example 1 above. 

39 

 APPENDIX A 

LIST OF ALL CTG CATEGORIES 

 Existing CTGS: 

1. Design criteria for Stage I Vapor Control Systems, Gasoline Service Stations, U.S. EPA, 

OAQPS, November 1975. 

Control Methods for Surface Coating Operations (EPA450/2-76-028). 

Surface Coatings of Cans, Coils, Paper, Fabric, Automobiles and Light-Duty Trucks (EPA450/2-77-008). 
4. Solvent Metal Cleaning/Degreasing Operations (EPA450/2-77-022). 

5. Refinery Vacuum Producing Systems, Wastewater Separators and Process Unit Turnarounds 

(EPA-450/2-77- 

025). 

6. Hydrocarbons from Tank Truck Gasoline Loading Terminals (EPA-450/2-77-026). 

.:7@ Surface Coatings of Metal Furniture (EPA-450/2-77-032). 

Surface Coatings of Insulation of Magnetic Wire (EPA450/2-77-033). 

Surface Coatings of Large Appliances (EPA-450/2-77-034). 

10. Bulk Gasoline Plants (EPA-450/2-77-035). 

11. Storage of Petroleum Liquids in Fixed Roof Tanks (EPA450/2-77-036). 

12. Use of Cutback Asphalt (EPA-450/2-77-037). 

Surface Coating of Miscellaneous Metal Parts and Products (EPA-450/2-78-015). 

14. Stationary Sources (EPA-450/2-78-022). 

15. Manufacture of Synthesized Pharmaceutical Products (EPA-450/2-78-029) - 

16. Manufacture of Pneumatic Rubber Tires (EPA-450/2-78- 

030). 

@l . Factory Surface Coating of Flat Wood Paneling (EPA4 50/2-78-032) . 

18. Graphic Arts - Rotogravure and Flexography (EPA-450/278-033). 

19. Leaks from Petroleum Refinery Equipment (EPA-450/2-78- 

036). 

20. Petroleum Liquid Storage in External Floating Roof Tanks (EPA-450/2-78-047). 

21. Perchloroethylene Dry Cleaning Systems (EPA-450/2-78- 

050). 

22. Leaks from Gasoline Tank Trucks and Vapor Collection Systems (EPA-450/2-78-051). 

23. Vplatile Organic Liquid Storage in Floating and Fixed Roof Tanks, DRAFT, August 1981. 

24. Large Petroleum Dry Cleaners (EPA-450/3-82-009). 

25. Fugitive Emission Sources (EPA-450/3-82-010). 
26. Synthetic Organic Chemical Polymer and Resin Manufacturing Equipment (EPA-450/3-83-

006). 

27. Equipment Leaks from Natural Gas/Gasoline Processing Plants (EPA-450/2-83-007). 

28. Manufacture of High-Density Polyethylene, 

Polypropylene, and Polystyrene Resins (EPA-450/3-83- 

008). . 

29. Synthetic Organic chemical Manufacturing Industry (SOCMI) (EPA-450/3-84-015). 

 

CTGs in progress: 

l@ Adhesives 

2. Aerospace 

3. Autobody Refinishing 

4. Clean-up Solvents 

5. Consumer Products 

6. Marine Vessel Building and Repair 

7. Marine Vessel Loading and Unloading 

8. Petroleum and Industrial Wastewater 

9. Plastic Parts (Coatings-Business Machines) 

10 .Plastic Parts (Coatings-Other) 

ii. SOCMI Batch Processes 

12. SOCMI Distillation Operations 

13. SOCMI Reactor Processes 

14. Treatment, Storage & Disposal Facilities 

15. Web Offset Lithography 

 APPENDIX B 

CAPTURE EFFICIENCY MODEL RULE