SACRAMENTO METROPOLITAN 

AIR QUALITY MANAGEMENT DISTRICT 

STAFF REPORT 

Proposed Amendments to 

Rule 451, Surface Coating of Miscellaneous Metal Parts and Products 

September 27, 2010 

Prepared by: Marc Cooley 

Associate Air Quality Engineer 

David Yang 

Associate Air Quality Engineer 

Reviewed by: Kevin J. Williams, Ph.D. 

Program Coordinator 

Aleta Kennard 

Program Supervisor 

Approved by: Brigette Tollstrup 

Division Manager
Staff Report 

Rule 451 

September 27, 2010, Page 1 

BACKGROUND 

Ground level ozone is a secondary pollutant formed from photochemical reactions of nitrogen 

oxides (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Ozone is a 

strong irritant that adversely affects human health and damages crops and other environmental 

resources. As documented by the U.S. Environmental Protection Agency (EPA) in the most 

recent Criteria Document for ozone (U.S. EPA 2006), both short-term and long-term exposure to 

ozone can irritate and damage the human respiratory system, resulting in: 

• decreased lung function; 

• development and aggravation of asthma; 

• increased risk of cardiovascular problems such as heart attacks and strokes; 

• increased hospitalizations and emergency room visits; and 

• premature deaths. 

The District is currently designated as a nonattainment area for both the state and federal ozone 

standards. Since VOCs are a precursor to ozone, one of the strategies to control ozone 

pollution is to reduce VOC emissions from existing stationary sources. The projected 2011 

VOC emission inventory for Sacramento County includes 29 tons per year for miscellaneous 

metal parts and products coatings and 25 tons per year for metal furniture and fixtures coatings. 

Control Techniques Guidelines for Miscellaneous Metal and Plastic Parts Coatings

On October 7, 2008, EPA promulgated a Control Techniques Guidelines (CTG) for 

Miscellaneous Metal and Plastic Parts Coatings (EPA-453/R-08-003, September 2008). The 

CTG contains Reasonably Available Control Technology (RACT) guidelines and 

recommendations, including VOC content limits, specific exemptions, and recommended work 

practice procedures, for coatings applied on six different substrate categories: miscellaneous 

metal parts and products, miscellaneous plastic parts and products, transportation plastic parts, 

business machine plastic parts, the metal and plastic parts of pleasure craft, and motor vehicle 

materials. Section 182(b)(2) of the federal Clean Air Act (CAA) requires the District to 

implement RACT for the source categories included in the CTG. 

Rule 451, Surface Coating of Miscellaneous Metal Parts and Products

Rule 451 was first adopted on June 19, 1979 and last amended on September 25, 2008. The 

rule applies to coating, coating removal (stripping), surface preparation, and cleanup operations 

for miscellaneous metal parts and products. Miscellaneous metal parts and products include all 

metal parts and products which are not subject to other District coating rules. 

Staff is proposing to amend Rule 451 to incorporate the requirements of the CTG for the 

miscellaneous metal parts and products category as required by the Clean Air Act. The 

proposed amendments will strengthen the existing limits on three coating categories of 

miscellaneous metal parts and products. 
Staff Report 

Rule 451 

September 27, 2010, Page 2 

LEGAL MANDATES 

Federal Mandates:

The District is designated as a severe nonattainment area for the federal 8-hour ozone 

standard. Federal Clean Air Act section 172(c)(1) specifies 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) of the CAA provides that for nonattainment areas classified as “moderate” or 

worse, states must revise their SIPs to include RACT for sources of VOC emissions for each 

category of VOC sources covered by all CTG documents issued after November 15, 1990, and 

prior to the area’s date of attainment. 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, 

September 17, 1979). Pursuant to CAA Sections 108(b) and (c), EPA periodically publishes 

information regarding available controls. In developing Control Techniques Guidelines, EPA 

evaluates, among other things, the sources of VOC emissions and the available control 

approaches for addressing these emissions, including the costs of such approaches. CTG 

documents establish the presumptive minimum recommendations for RACT. 

On October 7, 2008, EPA promulgated a Control Techniques Guidelines for Miscellaneous 

Metal and Plastic Parts Coatings (EPA-453/R-08-003, September 2008). EPA’s CTG provides 

the presumptive minimum recommendations for RACT for various coating categories, including 

coatings for miscellaneous metal parts and products. The proposed amendments to Rule 451 

will satisfy the RACT requirements for coating operations for miscellaneous metal parts and 

products. In addition, many of the limits in Rule 451 are more stringent than the recommended 

limits in the CTG and, therefore, may be viewed as going beyond the RACT requirements. 

State Mandates:

The District is designated “serious” nonattainment for the state ozone standard. The California 

Clean Air Act requires areas designated as “serious” to adopt control measures required in 

Sections 40919 of the California Health and Safety Code (HSC). Amendments to Rule 451 

(adopted on September 25, 2008) were included in the “2009 Triennial Report and Plan 

Revision” (SMAQMD, 2010). The plan commitment for this rule also satisfies the following 

requirements: 

• California HSC Section 40919 requires districts designated serious nonattainment for 

ozone to adopt Best Available Retrofit Control Technology (BARCT) for all existing 

permitted sources. BARCT means an emission limitation that is based on the maximum 

degree of reduction achievable, taking into account environmental, energy, and 

economic impacts by each class or category of sources (HSC Section 40406). 

• Transport Mitigation Emission Control Requirements: Title 17, Section 70600 of the 

California Code of Regulations requires that districts within the areas of origin of 

transported air pollutants, as identified in Section 70500(c), include sufficient emission 

control measures (including “all feasible measures” and BARCT) in their attainment 

plans for ozone to mitigate the impact of pollution sources within their jurisdictions on 

ozone concentrations in downwind areas commensurate with the level of contribution. 

An upwind district must comply with the transport mitigation planning and 
Staff Report 

Rule 451 

September 27, 2010, Page 3 

implementation requirements set forth in this section regardless of its attainment status, 

unless the upwind district complies with the requirements of Section 70601. 

The limits proposed for Rule 451 have been implemented in the SCAQMD and are effective in 

SJVAPCD on January 1, 2011. Coatings that meet the proposed limits are available and are 

currently being used. Staff considers the proposed limits for Rule 451 to be feasible. The 

proposed amendments to Rule 451 will meet the BARCT requirements and fulfill the state plan 

commitment. 

CTG RECOMMENDATIONS FOR MISCELLANEOUS METAL PARTS AND PRODUCTS 

COATINGS 

The Control Techniques Guidelines document for Miscellaneous Metal and Plastic Parts 

Coatings (CTG) contains recommended VOC content limits for coatings applied to 

miscellaneous metal parts and products. This section addresses how the current rule coating 

categories match up with the CTG categories and limits, and how the CTG recommendations 

can be incorporated into Rule 451. 

The following table is a comparison of coating categories and VOC limits in the CTG for 

Miscellaneous Metal and Plastic Parts Coatings and the current version of Rule 451: 

CTG Recommendation for Metal Parts Current Version of Rule 451

Coating Category Air Dried Baked Coating Category Air Dried Baked

Camouflage 420 420 Camouflage 420 360 

Electrical Insulating 420 420 Electrical Insulating 340 275 

Extreme High-Gloss 420 360 Extreme High Gloss 420 360 

Extreme Performance 420 360 Extreme Performance 420 420* 

Heat-Resistant 420 360 Heat Resistant 420 360 

Metallic 420 420 Metallic/Iridescent 420 420 

Prefabricated 

Architectural Component 

420 275 

Prefabricated 

Architectural MultiComponent 420 280 Aluminum Coating for 

Window Frames and 

Door Frames 

420 420* 

Prefabricated 

Architectural Component 420 275 

Prefabricated 

Architectural OneComponent 420 280 Aluminum Coating for 

Window Frames and 

Door Frames 

420 420* 

Pretreatment Coatings 420 420 

Etching Filler 420 420 

Pretreatment Wash 

Primer** 420 420 

Silicone Release 420 420 Silicone Release Coating 420 420 

Solar-Absorbent 420 360 Solar Absorbent 420 360 

Non-Skid 420* 360* General One-component 340 280 All Other Coatings 340 275 

General Multicomponent 340 280 All Other Coatings 340 275 
Staff Report 

Rule 451 

September 27, 2010, Page 4 

CTG Recommendation for Metal Parts Current Version of Rule 451

Coating Category Air Dried Baked Coating Category Air Dried Baked

High Performance 

Architectural 740 740 

High Temperature 420 420 

Military Specification 340 280 

Mold-Seal 420 420 

Pan Baking 420 420 

Repair and Touch Up 420 360 

Vacuum-Metalizing 420 420 

Drum Coating, New 

Exterior 340 340 

Drum Coating, New, 

Interior 420 420 

Drum Coating, 

Reconditioned, Exterior 420 420 

Drum Coating, 

Reconditioned, Interior 500 500 

All Other Coatings 340 

275 

 *This VOC limit in the current version of Rule 451 is less stringent than the VOC limit listed for the corresponding 

coating category in the CTG. 

**In the current version of Rule 451, the definition of “pretreatment wash primer” does not limit the solids content 

by weight. In the CTG, the definition of “pretreatment coating” limits the solids content to no more than 12 

percent by weight, and the definition of “etching filler” limits the solid to less than 23 percent solids by weight. 

Both categories, pretreatment coating and etching filler, are categorized as pretreatment wash primer in the 

current version of Rule 451. 

The coating categories for aluminum coatings for window frames/door frames and non-skid 

coatings that are included in the current version of Rule 451 are not listed as coating categories 

in the CTG. Aluminum coatings for window frames/door frames would be classified under the 

CTG as “prefabricated architectural one-component or multi-component coatings,” and non-skid 

coatings would be classified under the CTG as “general one-component coatings.” 

The recommended VOC limits for the coating categories in the CTG, except for the VOC limit 

for the baked aluminum coatings for window frames/door frames, baked extreme performance, 

and non-skid coatings, are either equivalent to or less stringent than the VOC limits listed in the 

corresponding categories in the current version of Rule 451. Therefore, to meet the RACT 

requirements, Staff is proposing to lower the VOC limits for baked aluminum coatings for 

window frames/door frames, baked extreme performance, and non-skid coatings in Rule 451 to 

be consistent with the VOC limits recommended by the CTG. 

SUMMARY OF PROPOSED AMENDMENTS 

The significant proposed amendments for Rule 451 are summarized below. For a detailed list 

of changes, see Appendix B. 

Rule 451 Proposed Amendments

The following table summarizes the proposed VOC content limits of coatings for miscellaneous 

metal parts and products (other coating categories remain unchanged): 
Staff Report 

Rule 451 

September 27, 2010, Page 5 

 VOC CONTENT: Grams/Liter (Lbs/Gal) 

less water and exempt compounds 

EXISTING COATING CATEGORY AIR DRIED BAKED 

Aluminum Coating for Window Frames 

and Door Frames 420 (3.5) 

420 (3.5) 

Effective (six months after 

date of adoption) 

275 (2.3) 

Extreme Performance 420 (3.5) 

420 (3.5) 

Effective (six months after 

date of adoption) 

360 (3.0) 

Non-Skid 

This category will sunset on (six months 

after date of adoption) and thereafter be 

subject to All Other Coatings 

420 (3.5) 360 (3.0) 

 

NEW COATING CATEGORY AIR DRIED BAKED 

Etching Filler 420 (3.5) 420 (3.5) 

The proposed amendments to Rule 451 would make the rule consistent with other District 

coating rules by expanding the applicability to include any person who supplies, sells, offers for 

sale, manufactures, distributes, uses, applies, or solicits the use or application of any coating, 

coating remover (stripper), surface preparation material, and cleanup material for miscellaneous 

metal parts and products. 

The following proposed amendments to Rule 451 would make the rule at least as stringent as 

the recommended requirements in the CTG applicable to coatings for miscellaneous metal parts 

and products: 

• Add an exemption for automobile and light duty-truck coating operations during 

manufacture on an assembly line, which are covered by a different CTG (Control 

Techniques Guidelines for Automotive and Light-Duty Truck Assembly Coatings, EPA453/R-08-006, September 2008). Currently, there are no sources in Sacramento County 

to which this CTG applies. 

• Reduce the VOC limits for the following types of miscellaneous metal parts and products 

coatings: baked aluminum coatings for window frames/door frames and baked extreme 

performance coatings. 

• Reduce the VOC limit for non-skid coatings to be equivalent to the recommended limits 

in the CTG. The non-skid coating would be classified as “general one-component 

coatings” in the CTG because this coating category is not specifically listed in the CTG. 

Six months after the date of adoption, the VOC limits for this coating category would be 

the same limits as for the “all other coatings” category. Staff is proposing to sunset this 

coating category to simplify the rule. Any non-skid coating applied to miscellaneous 

metal parts and products would be subject to the VOC content of the “all other coatings” 

category. 

• Add and/or modify definitions for consistency with the CTG. 
Staff Report 

Rule 451 

September 27, 2010, Page 6 

EMISSIONS IMPACT 

The District’s projected emission inventory for 2011 is 29 tons per year from miscellaneous 

metal parts and products coatings and 25 tons per year from metal furniture and fixture 

coatings, not including solvent usages. Even though there are changes to VOC limits, no 

sources are affected by the proposed amendments to this rule, and therefore, no emission 

reductions are expected. 

COST IMPACT 

Section 40703 of the California HSC requires that the District consider and make public its 

findings relating to the cost effectiveness of implementing an emission control measure. 

No sources are affected by the proposed amendments to this rule. As a result, no additional 

compliance costs will be incurred. 

INCREMENTAL COST EFFECTIVENESS 

The District is required to identify one or more potential control options that achieve the 

emission reduction objective for the regulation (California Health and Safety Code Section 

40920.6). 

No source is affected by the proposed amendment to the rule, and therefore, no incremental 

cost effectiveness analysis is necessary for this rule. 

SOCIOECONOMIC IMPACT ANALYSIS 

HSC Section 40728.5 requires a district to perform an assessment of the socioeconomic 

impacts before adopting, amending, or repealing a rule that will significantly affect air quality or 

emission limitations. The District Board is required to actively consider the socioeconomic 

impacts of the proposal and make a good faith effort to minimize adverse socioeconomic 

impacts. 

HSC Section 40728.5 defines “socioeconomic impact” as follows: 

1. The type of industries or business, including small business, affected by the rule or 

regulations. 

2. The impact of the proposed rule or regulations on employment and the economy of the 

region affected by the adoption of the rule or regulation. 

3. The range of probable costs, including costs to industry or business, including small 

business, of the rule or regulation. 

4. The availability and cost-effectiveness of alternatives to the rule or regulation being 

proposed or amended. 

5. The emission reduction potential of the rule or regulation. 

6. The necessity of adopting, amending, or repealing the rule or regulation to attain state 

and federal ambient air standards. 
Staff Report 

Rule 451 

September 27, 2010, Page 7 

Type of industry or business, including small business, affected by the proposed rule: Rule 451 

applies to any person/business that performs coating of miscellaneous metal parts and 

products. These operations are performed in a shop environment. This rule also applies to the 

manufacturers, sellers or distributors of coatings and solvents for these operations. 

Impact on employment and economy in the District of the proposed rule: Staff has found that all 

applicable facilities are already in compliance with the amendments to Rule 451; therefore, no 

impact is expected from the proposed amendments to Rule 451. 

Range of probable costs, including costs to industry or business, including small business of the 

proposed rule: No costs are expected for industry/business subject to Rule 451. 

Availability and cost effectiveness of alternatives to the proposed rule: An alternative to the 

proposed amendments to the rule is to not adopt them. However, the District is required by 

Section 182(b)(2) of the Clean Air Act to revise the SIP to include RACT rules for source types 

covered by CTG documents. If the proposed amendments to Rule 451 are not adopted, the 

District will not fulfill the federal RACT requirements or state mandates discussed previously in 

the Legal Mandates section. 

 

Emission reduction potential of the proposed rule: The proposed amendments to Rule 451 are 

not expected to achieve emission reductions. 

Necessity of adopting the rule: Staff finds that the proposed amendments to Rule 451 are 

necessary to satisfy the requirements of Section 182(b)(2) of the federal Clean Air Act, which 

requires the District adopt RACT for CTG source categories. The proposed amendments to 

Rule 451 are needed to implement RACT requirements for miscellaneous metal parts and 

products as recommended by the CTG (EPA-453/R-08-003, September 2008). 

PUBLIC COMMENTS 

Staff held a public workshop to discuss the proposed amendments on September 16, 2010. A 

public notice for the workshop was mailed to interested and potentially affected parties, 

including all permitted stationary sources (except for gas stations and dry cleaners), industry 

associations, coating manufacturers and suppliers, and all persons who have requested to 

receive rulemaking notices. The notice was also published as a display ad in the Sacramento 

Bee and posted on the District web site. The draft rule and staff report were available for public 

review prior to the public workshop. 

Staff received comments and questions concerning Rule 451 at the workshop, as well as written 

comments from coating manufacturers and distributors. CARB and EPA reviewed the proposed 

amendments and had no comments. All comments and responses are included in Appendix C. 

Oral comments at the workshop as well as subsequent written comments from two coating 

manufacturers expressed concern that VOC-compliant pretreatment wash primers may not be 

available if they must meet the proposed addition of solids content to the definition of the 

coating category. 

In the current version of Rule 451, pretreatment wash primers must contain at least 0.5% acid 
Staff Report 

Rule 451 

September 27, 2010, Page 8 

by weight, but there is no restriction on solids content. Staff had proposed to add to this 

definition a restriction limiting the solids content to no more than 12% by weight, consistent with 

the definition in the CTG. However, the CTG also contains another coating category, “etching 

filler,” that is also applied to bare metal surfaces and must contain at least 0.5% acid by weight 

and less than 23% solids by weight. The CTG VOC limits for etching filler are the same as the 

limits for pretreatment wash primer (baked: 420 g/l, air-dried: 420 g/l). Therefore, in response to 

these comments, Staff is proposing to add the category “etching filler,” with the same VOC limits 

as pretreatment wash primer, consistent with the CTG. 

Several other comments and questions concerned the initial proposal to prohibit atomization of 

cleanup and surface preparation materials. The commenters stated that if surface preparation 

or cleanup could not be performed using a spray, then operators would need to prepare 

surfaces or clean equipment using solvent-laden towels and rags, a less effective cleaning 

technique that may also increase spillage and VOC emissions. Staff had proposed this 

workplace practice because the CTG had recommended that equipment cleaning be performed 

without atomizing the cleaning solvent with all spent solvents captured in closed container. 

However, the CTG did not recommend a VOC limit for the materials used for cleanup or surface 

preparation. The VOC limit for cleanup and surface preparation materials in Rule 451 is 25 g/l. 

Staff discussed this issue with EPA. EPA responded that the stringent 25 g/l VOC content limit 

for cleanup and surface preparation materials would be considered an equivalent control to the 

prohibition of atomizing cleanup and surface preparation materials, and this workplace practice 

need not be required. South Coast AQMD Rule 1171, Surface Cleaning Operations, also does 

not require these work practice requirements when the cleaning solvent contains 25 g/l or less. 

Therefore, in response to comments, Staff is no longer proposing to prohibit atomization of 

cleanup and surface preparation materials. 

ENVIRONMENTAL REVIEW AND COMPLIANCE 

Staff received a comment that tertiary butyl acetate should be exempted from the definition of 

VOC to reduce the flammability risks associated with cleaning and gun-flushing with acetonebased cleaners and coatings. With the current proposal, Staff is not proposing to change the 

VOC limit of 25 g/l for cleaning materials that was established in the September 2008 

amendments of Rule 451 and went into effect in September 2009; therefore, this would not be 

an impact of the current proposal. In addition, the rule does not dictate the use of any specific 

compound. Nevertheless, Staff has considered the potential flammability risks associated with 

the use of acetone. 

Many conventional cleaning solvents, such as toluene, xylene, methyl ethyl ketone and 

isopropyl alcohol are as flammable as acetone. Acetone has a lower flashpoint (-4 °F) than 

conventional solvents. However, its lower explosive limit of 26,000 ppmv in air is higher than 

other solvents, and this concentration is not likely to be achieved in a well-ventilated shop 

environment. In addition, businesses are required to report the storage and use of flammable 

materials to local fire departments, which in turn require permits with conditions that may include 

specifications for sprinkler systems, electrical systems, ventilation, and containment. 

Coating facilities in Sacramento are already using acetone for cleaning operations, and Staff is 

not aware of any flammability problems associated with its use. Requirements for solvents to 

contain 25 g/l or less VOC have been in effect in South Coast AQMD Rule 1171, Solvent 
Staff Report 

Rule 451 

September 27, 2010, Page 9 

Cleaning Operations, since 2003. Sources there have largely used acetone to comply, with no 

significant adverse effects. Therefore, Staff considers the flammability concerns regarding the 

use of acetone to be unwarranted. 

California Public Resources Code (Section 21159) requires an environmental analysis of the 

reasonably foreseeable methods of compliance. The proposed amendments to Rule 451 are 

not expected to require any source within the District to change its operations to comply. 

Staff finds that the proposed rule is exempt from the California Environmental Quality Act as an 

action by a regulatory agency for protection of the environment (Class 8 Categorical Exemption, 

Section 15308 State CEQA Guidelines) and because it can be seen with certainty that there is 

no possibility that the activity in question may have a significant adverse effect on the 

environment. (Section 15061(b)(3), State CEQA Guidelines). 

FINDINGS 

The California Health and Safety Code (HSC), Division 26, Air Resources, requires local 

districts to comply with a rule adoption protocol as set forth in Section 40727 of the Code. This 

section has been revised through legislative mandate to contain six findings that the District 

must make when developing, amending, or repealing a rule. The findings and their statutory 

definitions are listed in the following table. 

Rule 451 – Required Findings

Finding Required Finding for Rule 451 

Authority: The District must find that a provision of 

law or of a state or federal regulation permits or 

requires the District to adopt, amend, or repeal the 

rule. 

The District is authorized to adopt and amend Rule 451 

by California Health and Safety Code (HSC) Sections 

40001, 40702, 40716, 41010 and 41013. [HSC Section 

40727(b)(2)]. 

Necessity: The District must find that the rulemaking 

demonstrates a need exists for the rule, or for its 

amendment or repeal. 

It is necessary to amend Rule 451 to comply with the 

Reasonably Available Control Technology requirements 

of the federal Clean Air Act Sections 172(c)(1) and 

182(b)(2)(A), and BARCT requirements of HSC Section 

40919(a)(3) [HSC Section 40727(b)(1)]. 

Clarity: The District must find that the rule is written 

or displayed so that its meaning can be easily 

understood by the persons directly affected by it. 

Staff has reviewed the proposed amendments to the rule 

and determined that it can be understood by the affected 

parties. In addition, the record contains no evidence that 

people directly affected by the rule cannot understand 

the rule. [HSC Section 40727(b)(3)]. 

Consistency: The rule is in harmony with, and not in 

conflict with or contradictory to, existing statutes, 

court decisions, or state or federal regulations. 

The proposed amendments to the rule do not conflict 

with, and are not contradictory to, existing statutes, court 

decisions, or state or federal regulations. [HSC Section 

40727(b)(4)]. 

Non-Duplication: The District must find that either: 

1) The rule does not impose the same requirements 

as an existing state or federal regulation; or (2) that 

the duplicative requirements are necessary or proper 

to execute the powers and duties granted to, and 

imposed upon the District. 

The proposed amendments to the rule do not duplicate 

any existing state or federal regulations. [HSC Section 

40727(b)(5)]. 
Staff Report 

Rule 451 

September 27, 2010, Page 10 

Finding Required Finding for Rule 451 

Reference: The District must refer to any statute, 

court decision, or other provision of law that the 

District implements, interprets, or makes specific by 

adopting, amending or repealing the rule. 

In adopting the proposed amendment to the rule, the 

District is implementing the requirements of HSC 

Sections 40919(a)(3) and Sections 172(c)(1) and 

182(b)(2)(A) of the federal Clean Air Act. [HSC Section 

40727(b)(6)] 

Additional Informational Requirements: In 

complying with HSC Section 40727.2, the District 

must identify all federal requirements and District 

rules that apply to the same equipment or source 

type as the proposed rule or amendments. 

Appendix A includes a comparison with federal 

requirements. [HSC Section 40727.2]. 

REFERENCES 

1. Sacramento Metropolitan Air Quality Management District, 2009 Triennial Report and Plan 

Revision, January 28, 2010. 

2. San Joaquin Valley Air Pollution Control District. Final Draft Staff Report for Proposed 

Amendments to Rule 4603, Surface Coating of Metal Parts and Products, and Rule 4684, 

Polyester Resin Operations, August 2009. 

3. South Coast Air Quality Management District, Rule 1107 – Coating of Metal Parts and 

Products, January 6, 2006. 

4. South Coast Air Quality Management District, Rule 1171 – Solvent Cleaning Operations, 

August 2, 2002. 

5. South Coast Air Quality Management District, Rule 1171 – Solvent Cleaning Operations, 

May 1, 2009. 

6. U.S. Environmental Protection Agency. “Air Quality Criteria for Ozone and Related 

Photochemical Oxidants”, (EPA 600/R-05/004aF), February 2006. 

7. U.S. Environmental Protection Agency. Control Techniques Guidelines for Automobile and 

Light-Duty Truck Assembly Coatings. (EPA-453/R-08-006), September 2008. 

8. U.S. Environmental Protection Agency. Control Techniques Guidelines for Miscellaneous 

Metal and Plastic Parts Coatings. (EPA-453/R-08-003), September, 2008. 
Staff Report 

Rule 451 

September 27, 2010, Page 11 

APPENDIX A 

40727.2 Matrix for Proposed Amendments to Rule 451, Surface Coating of Miscellaneous 

Metal Parts and Products 

 Comparative Requirements 

Elements of 

Comparison 

Specific 

Provisions Proposed Rule 451 

Best Available Control 

Technology (BACT)/ Lowest 

Achievable Emission Rate 

(LAER) 

Applicability Any person who supplies, sells, 

offers for sale, manufactures, 

distributes, uses, applies, or 

solicits the use or application of 

any coating for miscellaneous 

metal parts and products within 

the District.

Surface coating of miscellaneous 

metal parts and products 

Exemptions Usage of materials exceeding 

VOC content less than 55 gal/yr 

Coating of prefabricated 

architectural components or 

structures not coated in a shop 

environment, motor vehicles, 

aircraft or aerospace vehicles, 

components, and tooling, cans, 

coils, or magnetic wire; magnetic 

data storage discs; metal parts of 

pleasure crafts 

Adhesives, safety-indicating 

coatings, stencil coatings; 

conformal coatings; hand lettering 

coatings; automobile and lightduty truck assembly coatings 

Coatings from aerosol containers 

less than or equal to 1 liter 

Touch-up coating and repair 

coating operations, application of 

texture coating 

Averaging 

Provisions 

 None 

Units Grams of VOC per liter of material 

or pounds of VOC per gallons of 

material 
Staff Report 

Rule 451 

September 27, 2010, Page 12 

 Comparative Requirements 

Elements of 

Comparison 

Specific 

Provisions Proposed Rule 451 

Best Available Control 

Technology (BACT)/ Lowest 

Achievable Emission Rate 

(LAER) 

 Emission limits specified in 

Sections 301-303 and 305.3-

305.4, or install emissions control 

equipment specified in Section 

306 with overall system efficiency 

of ≥ 90%. 

For spray booths with an exhaust 

less than 30,000 acfm, use low 

VOC materials achieved in 

practice and high-transfer 

efficiency equipment. 

For spray booths with an exhaust 

flow rate greater than or equal 

30,000 acfm, use an air pollution 

control device when it is costeffective; otherwise, use low VOC 

materials achieved in practice and 

high transfer efficiency equipment. 

Emissions 

Limits 

Compliance 

alternatives 

Emission control equipment Emission control equipment 

Work Practice 

Requirements 

 Closed containers for disposal of 

materials used for surface 

preparation, cleanup and coating 

removal; closed containers; 

minimizing spills, and conveyance 

of VOC materials using closed 

containers or pipes. 

Closed containers for disposal of 

materials used for surface 

preparation, cleanup and coating 

removal; closed containers; 

cleanup to take place in an 

enclosed system, no atomizing of 

cleanup or surface preparation 

solvent. 

Recordkeeping Currently used list of materials; 

product data sheets of all 

materials; daily and monthly 

usages; recordkeeping for air 

pollution control equipment if 

used. 

Monitoring/ 

Records 

Frequency Daily and/or monthly for coating 

usages. Records kept for a 

continuous five-year period. 

Monitoring/ 

Testing 

Test Methods Applicable test methods are 

specified under Section 502 of the 

rule. 

 Frequency No frequency specified in the rule 
Staff Report 

Rule 451 

September 27, 2010, Page 13 

APPENDIX B 

LIST OF CHANGES TO RULE 

Rule 451, Surface Coating of Miscellaneous Metal Parts and Products 

NEW 

SECTION 

NUMBER 

EXISTING 

SECTION 

NUMBER 

PROPOSED CHANGES 

102 Same Expanded the applicability to include any person who supplies, sells, 

offers for sale, manufactures, distributes, uses, applies or solicits the 

use or application of any miscellaneous metal parts and products 

coatings, coating removers (strippers), surface preparation material, 

and cleanup material. 

110 Same Revised section references. 

111 Same Revised language for consistency with other District rules. Removed 

the coating operation description specific to each District rule. 

Updated and capitalized rule titles. 

N/A 111.6 Removed section because Rule 456 was already listed. 

112 Same Revised section references. 

113 Same Changed the term “provisions” to “requirements” for rule consistency.

114 Same Revised language for clarification. 

114.2 Same Changed to the use the term “texture coating” consistent with the 

CTG (EPA-453/R-08-003). 

116 N/A Added exemption for automobile and light-duty truck assembly 

coating operations. 

205 206 Moved definition of “application equipment” to be in alphabetical 

order. 

206 205 Section renumbered. 

207 N/A Added definition of “automobile” to clarify the automobile and lightduty assembly operations exemption. 

208 N/A Added definition of “automobile and light-duty truck assembly 

operations” to clarify the automobile and light-duty assembly 

operations exemption. 

209-213 207-211 Section renumbered. 

214 212 Revised language for clarification. 

NA 213 Removed “conformal coating” definition because it is no longer used 

in the rule. 

215 214 Section renumbered. 

216 215 Revised the definition of “electrical insulating coating” to be 

consistent with the CTG. 

217 216 Section renumbered. 

N/A 217 Removed “enclosed gun cleaner” definition because it no longer 

relates to any requirement. 

219 N/A Added definition of “etching filler” consistent with the CTG. 

220 219 Section renumbered. 

221 220 Revised definition of “extreme high gloss coating” to update the test 

method and added “at least” to show at least 75% reflectance. 

222-228 221-227 Sections renumbered. 
Staff Report 

Rule 451 

September 27, 2010, Page 14 

NEW 

SECTION 

NUMBER 

EXISTING 

SECTION 

NUMBER 

PROPOSED CHANGES 

229 N/A Added definition of “light-duty truck” to clarify the automobile and 

light-duty assembly operations exemption. 

230 228 Section renumbered. 

231 N/A Added definition of “mask coating” consistent with the CTG. 

232-235 229-232 Section renumbered. 

236 233 Changed “non-compliant coating” to “non-compliant material”. 

Revised definition to apply to all coatings, coating removers, 

cleaning or surface preparation materials that do not comply with the 

VOC limits and are not exempt. Section references updated. 

237 234 Added sunset date for “non-skid coating” coating category after 

which these coatings are subject to “all other coating” category. 

238 235 Section renumbered. 

239 236 Revised definition of “pretreatment wash primer” to include percent 

solids by weight, consistent with the CTG. 

240 237 Revised definition of “repair coating” for clarification. 

241-246 238-243 Section renumbered. 

247 244 Revised definition of “stencil coating” for clarification. 

248 245 Section renumbered. 

249 246 Revised the term “textured finish” to “texture coating” to be 

consistent with the CTG. 

250-252 247-249 Section Renumbered. 

301 Same Lowered VOC content limits, effective 6 months after date of 

adoption, for baked aluminum coating for window frames and door 

frames and baked extreme performance coatings, consistent with 

the CTG. Added sunset date for non-skid coatings and updated 

section references. Added new coating category for “etching filler” 

and its VOC limits, consistent with the CTG. 

302 Same Removed expired date. Added new coating category for “etching 

filler” and its VOC limits. 

305 Same Removed expired dates and sections that have expired. 

306 Same Revised section references. 

401 Same Revised language to include coating removers, surface preparation 

and cleanup materials for rule consistency. 

402 Same Revised section references. 

403 Same Revised section references. 

404 Same Revised section references. 

407 Same Revised section references. 

501 Same Added section reference. 

501.1 Same Clarified in section 501.1.a that requirement is applicable to coating 

removers and surface preparation and cleanup materials, in addition 

to the coatings. Revised section references. 

501.2 Same Revised section references. 

501.3 Same Clarified that requirement is applicable to coating removers and 

surface preparation and cleanup material in addition to coatings. 

Revised section references. 
Staff Report 

Rule 451 

September 27, 2010, Page 15 

NEW 

SECTION 

NUMBER 

EXISTING 

SECTION 

NUMBER 

PROPOSED CHANGES 

501.5 Same Removed expired date and section that has expired. 

502.5 Same Revised section reference. 

502.7 N/A Added EPA test method to determine the solids content for coatings. 

502.8 502.7 Section renumbered. 
Staff Report 

Rule 451 

September 27, 2010, Page 16 

APPENDIX C 

COMMENTS AND RESPONSES 

Public Workshop for Rules 101, 451 and 459

September 16, 2010, 2:00 PM 

Attendees: 

Allen Cripe, CalTrans Josh Cox, Jerry’s Paint 

Brad Gacke, SMUD June Livingston, BERC 

Brett Hayes, Hayes Brothers Collision Kelly Hitt, Nestle Waters North America 

Brittany Marcotte, Nestle Waters North America Kendall McCane, Jerry’s Paint 

Bryon Theis, 3M Kevin Holley, MAC’s Distribution 

Cerlut Fre, Sherwin Williams Kevin Thompson, Thompson Sales 

Clifford Waters, Sherwin-Williams Larry Medrano, PBE Inc 

Dale Schell, Jims Color Corner Lisa Dobeck, Caltrans 

Dan Porreau, Lyondell Basell Mark McCleskey, Jerry’s Paint 

Danny Nunez, Finish Masters Mark Tavianini, CARB 

Dave Fisher, Morrison Paint Supply Matt Stevens, Shanahan’s Autobody 

Dave Harshbarger, MAC’s Distribution Mike Veney, Sherwin Williams 

David Luer, MAC’s Distribution Pat Newcomb, Jerry’s Paint 

David M’Clune, California Autobody Association Pat Stickle, Angel Warehouse 

David Roznowski, Lyondell Basell Peter Bezech, California Autobody Association 

Debra Wynne, Original Paint Phil Brown, PPG Industries 

Dennis Barkman, Colors On Parade Rich Mott, Jerry’s Paint 

Deran Berggne, Terry’s Paint Rick Hays, MAC’s Distribution 

Eric Cooc, Precision Autobody Robert Blair, Finish Mater 

George Contos, Blomberg Window Shane Whitcomb, Ellis & Ellis Sign Systems 

Glenn Galbaugh, DuPont Company Stan Brecetu, 3M 

Grey Calhorn, Finish Master Steve Nesbitt, PCL 

Jason Kowen, Spies Hecker Terry Klemin, Matrix 

Jeanette Duncan, Ellis & Ellis Sign Systems Todd Everitt, Valspar Refinish 

Jeremy Tiner, Warehouse Paint Tom Walther, Jims Color Corner 

Jim Brett, CalTrans Vern Heffner, City of Sacramento Fleet Management 

Jim Cropper, CARB 

Oral Comments From the Public Workshop

Note: A combined workshop was held for proposed amendments to Rule 451, Rule 101 and Rule 

459. Only comments pertaining to the proposed amendments to Rule 451 are shown below. 

Other comments made during the public workshop will be added in the Staff Report for Rule 101 

or the Staff Report for Rule 459. 

Comment #1 Why is the definition of “pretreatment wash primer” in Rule 451 limited to no 

more than 12 percent solids by weight? The 12 percent weight content 

restriction is not feasible and no products are available. 

Response: The solids content proposed to be added to the definition of “pretreatment 
Staff Report 

Rule 451 

September 27, 2010, Page 17 

wash primer” is consistent with the CTG. However, in response to this 

comment and similar written comments from two coating manufacturers, 

Staff is now proposing to add to Rule 451 the category “etching filler,” which 

is a category contained in the CTG. The CTG states “etching filler” is 

defined as a coating which contains at 0.5% acid by weight and less than 

23% solids by weight, and is used instead of pretreatment wash primer 

followed by a primer. This effectively splits the current pretreatment wash 

primer category (which has no limit on solids content) into two categories, 

depending on the solids content. The VOC limits for pretreatment wash 

primer and etching filler in Rule 451 are the same: 420 g/l for both air-dried 

and baked coatings. The CTG limits for these categories are 420 g/l for 

both air-dried and baked coatings. A test method to determine the solids 

content of coatings was added as Section 502.7. 

Comment #2 Why is the weight percent solids for pretreatment wash primer in the 

proposed amendments to Rule 451 different in the proposed amendments 

to Rule 459? Rule 459 limits the solid content to no more than 16 percent 

by weight, which is feasible. 

Response: The solids content of no more than 16% solids by weight in the definition of 

Pretreatment Coating is feasible to meet the proposed VOC limit of 660 

grams per liter according the CARB’s Suggested Control Measure for 

Automotive Coatings. The current limit in Rule 451 for pretreatment wash 

primer is 420 grams per liter which is consistent with the CTG. Staff is not 

proposing to raise the solids content for pretreatment wash primers. 

However, Staff is proposing to add the coating category, etching filler, to 

Rule 451. See response to comment #1. 

Comment #3 The proposed amendments to Rule 451 prohibit atomization of cleanup 

materials. Does this affect gun cleaners? 

Response: The CTG recommended that equipment cleaning be performed without 

atomizing the cleaning solvent with all spent solvents captured in closed 

containers. However, the CTG did not recommend VOC content limits for 

these cleaning solvents. Rule 451 currently limits the VOC for cleanup and 

surface preparation materials to no more than 25 g/l. Staff discussed this 

issue with EPA. EPA responded that the 25 g/l requirement for cleanup 

and surface preparation materials would be considered an equivalent 

control to the prohibition of atomizing cleanup and surface preparation 

materials. Staff is no longer proposing to prohibit atomization of cleanup 

and surface preparation materials. Therefore, the proposed amendments 

will not affect gun cleaners. 

Comment #4 Can an operator put cleanup and surface preparation materials in a spray 

bottle and use it? If the alternative is to pour cleanup or surface preparation 

material on a towel or rag, then this method will likely create spillage which 

will result in more VOC emissions. 

Response: See response to comment #3. Staff is no longer proposing to prohibit 

atomization of cleanup and surface preparation materials. Therefore, 
Staff Report 

Rule 451 

September 27, 2010, Page 18 

operators can use any method or technique for cleaning operations or 

surface preparation as long as the VOC content of the cleanup or surface 

preparation material is no more than 25 g/l. 

Comment #5 Regarding the stripper limit in Rules 451 and 459, can the District allow for 

a low use exemption for stripper exceeding the 200 g/l limit? For products 

that meet the EPA’s NESHAP (HHHHHH), these products have higher 

limits than the 200 g/l limit. 

Response: The 200 g/l VOC limit for strippers is contained in the current, SIP-approved 

version of Rule 451. Adding a low use exemption would be a relaxation to 

the rule requirements. Facilities using strippers that contain methylene 

chloride must also comply with the National Emission Standards for 

Hazardous Pollutants for paint stripping (40 CFR Part 63, Subpart 

HHHHHH) as appropriate. Strippers that meet the 200 g/l VOC limit but 

don’t contain methylene chloride are currently available. 

Written Comments from Lyondell Basell 

Comment #6: Lyondell Basell requests that Tertiary Butyl Acetate (TBAc) be exempted for 

coatings in Rule 451. TBAc is an excellent solvent for industrial coatings 

including those listed in several categories in Rule 451. The cancer risk 

associated with using TBAc was based on a rodent tumor endpoint that has 

no relevance to human health since humans do not produce the protein 

responsible for tumor formation. Therefore, there is no reason to believe 

that TBAc used in Rule 451 will pose any chronic risk to humans. 

Response: The proposed changes to the VOC limits will not impact any sources in the 

District. Coating products are available on the market that comply with the 

VOC limits specified in the rule. At this time, it is not necessary to exempt 

TBAc as a VOC for the purpose of complying with limits in Rule 451. No 

specific exemption for TBAc is proposed to be included in Rule 451. 

However, further evaluation of TBAc will be done as part of the revisions to 

Rule 101, General Provisions and Definitions, to be considered in the first 

quarter of 2011. 

Comment #7: Lyondell requests that the AQMD propose an exemption for TBAc in Rule 

451. This will greatly reduce the flammability risks and emissions 

associated with cleaning and gun-flushing with acetone-based cleaners and 

coatings. 

Response: See response to Comment #6. The current VOC limit of 25 g/l for cleaning 

materials was established in the September 2008 amendments for Rule 

451 and went into effect in September 2009. Since the effective date of this 

requirement, coating facilities in Sacramento have been using acetone for 

their cleaning operations. Staff is not aware of any flammability problems 

associated with its use. Sources in the South Coast AQMD have been 

using primarily acetone to comply with the 25 g/l VOC limit for solvents that 

took effect in 2003, with no significant adverse effects. 
Staff Report 

Rule 451 

September 27, 2010, Page 19 

Written Comments from PPG Industries

Comment #8: PPG suspects the pretreatment wash primer definition is patterned after 

SCAMQD Rule 1107. PPG asks that if the District chooses to follow the 

precedent set by SCAQMD that they also include a relating coating type, 

etching filler. Both of these coatings typically use the same resin 

chemistries and are intended to be applied directly to metal for corrosion 

resistance. We propose that either the 12% solid maximum limit be 

withdrawn from the definition of Pretreatment Coating or the Etching Filler 

coating type be added to Rule 451. 

Response: To be consistent with the CTG and SCAQMD Rule 1107, Staff is proposing 

to add the coating category “etching filler” to Rule 451. See response to 

comment #1. 

Written Comments from DuPont Performance Coatings

Comment #9 There is inconsistency between the definitions of “pretreatment wash 

primer” in the proposed amendments to Rule 451 and “pretreatment 

coating” in proposed amendments to Rule 459. For all intent purposes, the 

coating types are synonymous. We would request that the current 

definition of Pretreatment Coating be retained as expressed in Rule 459, 

that is, 0.5% acid by weight and no more than 16% solids by weight. 

Response: See response to comment #2.