GOVERNING BOARD

Skip Barwick, Chair

Councilmember, City of Tulare 

Hub Walsh, Vice Chair

Supervisor, Merced County

Oliver L. Baines III

Councilmember, City of Fresno

Tony Barba

Supervisor, Kings County

Sally J. Bomprezzi

Councilmember, City of Madera

Dennis Brazil

Mayor, City of Gustine

Judith G. Case

Supervisor, Fresno County

David Couch

Supervisor, Kern County

Bob Elliott

Supervisor, San Joaquin County

Henry Jay Forman, Ph.D.

Appointed by Governor

Harold Hanson

Councilmember, City of Bakersfield

William O’Brien

Supervisor, Stanislaus County

Alexander C. Sherriffs, M.D.

Appointed by Governor

Tom Wheeler

Supervisor, Madera County

J. Steven Worthley

Supervisor, Tulare County

Seyed Sadredin

Executive Director

Air Pollution Control Officer

Northern Region Office

4800 Enterprise Way 

Modesto, CA 95356-8718

(209) 557-6400 • FAX (209) 557-6475

Central Region Office

1990 East Gettysburg Avenue

Fresno, CA 93726-0244

(559) 230-6000 • FAX (559) 230-6061

Southern Region Office

34946 Flyover Court

Bakersfield, CA 93308-9725

(661) 392-5500 • FAX (661) 392-5585

www.valleyair.org

DATE: February 21, 2013

TO: SJVUAPCD Governing Board

FROM: Seyed Sadredin, Executive Director/APCO

Project Coordinator: Errol Villegas/Jessi Fierro

RE: ADOPT PROPOSED AMENDMENTS TO 

RULE 1020 (DEFINITIONS)

RECOMMENDATION:

1. Adopt proposed amendments to Rule 1020 (Definitions). 

2. Authorize the Chair to sign the attached Resolution.

BACKGROUND:

Rule 1020 (Definitions) defines terms used throughout other District 

rules, including a list of compounds exempt from ozone regulations 

due to their low ozone forming potential. The District occasionally 

amends District Rule 1020 to update these definitions as they are 

revised by EPA. The District proposes to make updates related to the 

list of exempt compounds, including adding two new compounds and 

clarifying requirements for two existing compounds. The District has 

conducted a thorough review of the proposed amendments and has 

concluded that they will not cause adverse health impacts. 

DISCUSSION:

The first proposed rule amendment is to add dimethyl carbonate 

(DMC) and propylene carbonate (PC) to the District’s list of exempt 

compounds within the definition of volatile organic compounds (VOC) 

(Section 3.53) as a response to EPA findings that DMC and PC have 

a low potential to form ozone in the atmosphere. EPA found that 

these compounds are less photo-chemically reactive than ethane, and 

thus have a negligible contribution to ozone formation. EPA 

announced the exemption of DMC and PC in the Federal Register,
SJVUAPCD Governing Board

ADOPT PROPOSED AMENDMENTS TO RULE 1020 (DEFINITIONS)

FEBRUARY 21, 2013

2

effective February 2009 (included as Appendix B to the Final Draft Staff Report). By 

exempting these compounds, manufacturers of coatings or solvent cleaning materials 

have additional options with which to formulate low-VOC coatings and cleaning 

materials.

The District also proposes to remove unnecessary permitting requirements for two 

previously exempted compounds: methyl formate (MF) and tertiary-butyl acetate 

(TBAc). Based on the District’s analysis, the District determined that the current permit 

requirements included in Rule 1020 for MF and TBAc are not needed and will 

subsequently be removed.

The District evaluated the potential health impacts associated with these proposed 

amendments and concluded that they would not cause adverse health impacts. The 

District’s analysis was based on worst-case assumptions, including assuming that the 

use of the proposed exempt compounds would be entirely new, when, in fact, their use 

would be in lieu of other chemical compounds that could often pose a greater risk. 

While these compounds are exempt from VOC regulations under Rule 1020, the 

District’s permitting process evaluates the potential health risk from all new and 

modified operations to ensure that they do not cause significant health impacts to 

Valley residents.

A. Addition of dimethyl carbonate (DMC) as a VOC exempt compound

Section 3.53 of Rule 1020 defines VOC and lists compounds that are both organic and 

volatile, but are considered by the District to have low ability to form ozone. As 

discussed above, EPA found that dimethyl carbonate (DMC), a colorless, fastevaporating, water soluble solvent, is less photo-chemically reactive than ethane and 

has negligible contribution to the formation of ozone.

The flash point (the lowest temperature at which a liquid can vaporize to form an 

ignitable mixture in air) of DMC is higher than some solvents already in wide-spread 

use like acetone, ethyl acetate, and methyl ethyl ketone (MEK), thus making DMC an 

attractive replacement in applications that use these solvents. It also has the potential 

to replace isopropyl alcohol and trichloroethylene in cleaning and solvent applications. 

By contrast, the flammability of DMC may limit its use in consumer coatings, indoor 

application coatings, and as a hand-wipe cleaning solvent.

Inhalation is expected to be the primary pathway of human exposure as a result of 

solvent evaporation. This exposure would be similar to any other paint, sealant, and 

adhesive solvent that DMC would be intended to replace. There may also be some 

minor skin exposure from coatings splattering or careless mixing operations. Oral 

exposure would be rare and would be limited to accidental ingestion.

As a component of this rule amendment project, the District evaluated the potential 

health risks associated with the use of DMC and determined that, when used in the 

small amounts allowed under the District’s permitting exemptions (Rule 2020), the 
SJVUAPCD Governing Board

ADOPT PROPOSED AMENDMENTS TO RULE 1020 (DEFINITIONS)

FEBRUARY 21, 2013

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acute, chronic, and cancer risks are all significantly below the District’s health risk 

thresholds. In fact, DMC may replace some compounds such as xylene, toluene, 

MEK, and hexane, which have been identified as toxic air contaminants by the 

California Air Resources Board (ARB). In line with the District’s Risk-Based Strategy, 

the inclusion of DMC as a VOC exempt compound would likely decrease the overall 

health risk to Valley residents if used to replace toxics compounds such as those 

identified above (refer to the Final Draft Staff Report for more information about DMC 

and the District’s risk management review process).

B. Addition of propylene carbonate (PC) as a VOC exempt compound

PC is an odorless, non-viscous, clear liquid with a low vapor pressure, and very slow 

evaporation rate. It is combustible, with flash point of 132C. The compound is used in 

adhesives, paint strippers, and as a solvent for aerial pesticide application. PC is also 

used in more than 1,300 cosmetic products such as mascara, lip gloss, foundation, 

sunscreen, and deodorant. Other known applications of PC include special-purpose 

lubricant, general-purpose degreasers for industrial use, rubberized coatings, and nonflat aerosol paint products. PC may also be used as a tail solvent, because of its slow 

evaporation rate, and in certain solvent cleaning applications.

PC is not listed as a hazardous air pollutant under the Clean Air Act. It contains no 

chlorine or bromine and, therefore, it does not deplete the stratospheric ozone. Based 

on available data, PC has low acute toxicity, and there is no established airborne 

occupational exposure limit for PC. Because this compound has been approved for 

use in cosmetics, and its relatively low toxicity based on the best available data, it is 

anticipated that including PC as a VOC exempt compound will not pose a significant 

added risk to Valley residents.

C. Revision to methyl formate (MF) and tertiary-butyl acetate (TBAc) usage 

limitations

Currently, Sections 3.53.2 (applicable to TBAc) and 3.53.3 (applicable to MF) require 

any operator who elects to use more than one gallon per year (per facility) of either 

TBAc or MF to submit a permit application for the proposed use. Based on the 

District’s evaluation of potential health risks associated with the use of these 

compounds, these use limitations are not necessary, given their small potential risk. 

Additionally, the District’s permitting process evaluates the potential health risk from all 

new and modified operations, including use of these compounds, to ensure that they 

would not cause significant health impacts. Therefore, the District proposes to remove 

the permitting requirements included in Rule 1020 for TBAc and MF, while retaining 

their status as exempt compounds. 

Emission Reduction Analysis

Some manufacturers have expressed interest in replacing current coating solvents with 

these compounds, and emissions reductions would be expected from any VOC-
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ADOPT PROPOSED AMENDMENTS TO RULE 1020 (DEFINITIONS)

FEBRUARY 21, 2013

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containing solvents ultimately replaced by these newly exempted compounds. 

However, this action does not require the use of exempt compounds, and emissions 

reductions from the proposed amendments are therefore not claimed. 

Cost-Effectiveness Analysis

Since use of these compounds is strictly voluntary, there is no forced additional cost to 

operators or manufacturers for using coatings or solvent cleaning blends that contain 

DMC, PC, MF, or TBAc. 

Socioeconomic Analysis

California Health and Safety Code Section 40728.5 requires air districts to assess any 

socioeconomic impacts when adopting, amending, or repealing a rule that significantly 

affects air quality or emissions limitations. A socioeconomic impact analysis is not 

required for this rule amendment because the proposed amendments do not establish 

emission limitations and do not require the use of the exempt VOCs.

Rule Consistency Analysis

Under California Health and Safety Code Sections 40727 and 40727.2, before 

adopting or amending a regulation, an air district must make a rule consistency finding. 

The air district is to compare the emission limits, operating parameters, and 

recordkeeping requirements in its proposed regulation to corresponding elements in 

existing state or federal regulations that apply to the same equipment or source to 

ensure that requirements are not contradictory.

The proposed revisions to Rule 1020 do not include emission limits, operating 

parameters, or recordkeeping requirements. Furthermore, the proposed revisions align 

Rule 1020 definitions to definitions in other District and federal regulations. As such, 

Rule 1020 is consistent with other regulations on the same sources.

Environmental Impacts

Pursuant to the California Environmental Quality Act (CEQA), the District has reviewed 

the possible environmental impacts of adding DMC and PC to the exempt compounds 

list contained in District Rule 1020 (Definitions). As presented in the Final Draft Staff 

Report, EPA considers these chemicals to be exempt volatile organic compounds; 

these chemicals are already in use in California in cosmetics and other products; and, 

while manufacturers and other businesses may choose to reformulate existing 

products, the Rule 1020 amendments establish no requirement to do so.

There is no substantial evidence in the whole record before the District that the 

proposed amendments to Rule 1020 would cause any adverse effects on the 

environment. The District finds that the project is exempt per the general rule that 

CEQA applies only to projects which have the potential for causing a significant effect 
SJVUAPCD Governing Board

ADOPT PROPOSED AMENDMENTS TO RULE 1020 (DEFINITIONS)

FEBRUARY 21, 2013

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on the environment (CEQA Guidelines §15061(b)(3)). For these reasons, the District is 

proposing to file a Notice of Exemption upon Board adoption of the proposed 

amendments to Rule 1020.

Rule Development Process

Draft amendments to Rule 1020 and the Draft Staff Report were published and made 

available to stakeholders for their review and comments 30 days prior to a public 

workshop that was held on December 29, 2010. Comments received from 

stakeholders, ARB, and EPA regarding the original proposed amendments of DMC and 

PC were evaluated and, if appropriate, incorporated into the draft amendments to the 

rule.

The District published the notice of the public hearing for the proposed rule 

amendments in general circulation newspapers in each of the eight San Joaquin Valley 

counties. The District also posted the proposed amendments on its website prior to the 

public hearing.

FISCAL IMPACTS:

No fiscal impact to the District is expected to result from this action.

Attachments:

Attachment A. Resolution for Proposed Amendments to Rule 1020 (4 pages)

Attachment B. Proposed Amendments to Rule 1020 (Definitions) (14 pages)

Attachment C. Final Draft Staff Report with Appendices for Proposed Amendments to Rule 1020 

(52 pages)