SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Final Staff Report: Rule 1020 (Definitions) February 21, 2013

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SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

FINAL STAFF REPORT

Proposed Amendments to Rule 1020 (Definitions)

February 21, 2013

Prepared by: Lisa Van de Water, Air Quality Specialist

Reviewed by: Brian Clerico, Air Quality Engineer

Glenn Reed, Senior Air Quality Specialist

Anna Myers, Senior Air Quality Specialist

Leland Villalvazo, Supervising Air Quality Specialist

Jessi Fierro, Supervising Air Quality Specialist

Mike Oldershaw, Manager, Compliance

Errol Villegas, Program Manager, Strategies and Incentives

Samir Sheikh, Director, Strategies and Incentives

I. SUMMARY

Rule 1020 (Definitions) defines terms used throughout other San Joaquin Valley Air 

Pollution Control District (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 the 

Environmental Protection Agency (EPA). The District proposes to make several 

updates related to the list of exempt compounds, including adding several additional 

compounds and clarifying requirements for several existing compounds. 

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, effective February 2009 (included as Appendix B). By exempting 

these compounds, manufacturers of coatings or solvent cleaning materials have 

additional options with which to formulate low-VOC coatings and cleaning materials.
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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 San 

Joaquin Valley (Valley) residents.

II. RULE DEVELOPMENT PROCESS

As part of the rule development process, the District posted draft amendments to Rule 

1020 and solicited comments from the public, stakeholders, the California Air 

Resources Board (ARB), and EPA over a 30-day period just prior to hosting a public 

workshop on December 29, 2010. The District postponed further action on the 

proposed amendments to Rule 1020 based on a request by ARB to allow them an 

opportunity to further review the issue on a statewide basis. ARB ultimately did not 

publish such a review, and the District proceeded with evaluating and preparing the 

proposed amendments to Rule 1020, consistent with EPA’s 2009 ruling.

The District published and made available the proposed amendments to Rule 1020 to 

stakeholders for review prior to a public hearing of the Governing Board to consider 

adoption of the proposed rule amendments. The District evaluated comments received 

and incorporated them as appropriate. The proposed amendments are scheduled to be 

presented to the Governing Board during a public hearing on February 21, 2013.

III. BACKGROUND

Not all organic compounds have equal potential to form ozone in the atmosphere. EPA 

has revised the federal definition of VOCs several times to exclude organic compounds 

from the definition of VOCs based on their negligible contribution to ozone formation. 

By adding a compound to the list of exempt compounds, EPA is encouraging its use as 

a replacement for other chemicals that are significantly more likely to contribute to 

ozone formation. Effective February 2009, EPA added DMC and PC to the federal 

exempt compounds list on the basis that these compounds are less photo-chemically 
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reactive than ethane and, thus, have negligible contribution to ozone formation. The 

EPA announced the delisting of these chemicals in the Federal Register, which is 

attached as Appendix B.

If a chemical can be replaced by one with a lower potential to form ozone, the amount of 

ozone formed in the atmosphere will be reduced. Because both DMC and PC appear to 

be likely candidates to replace VOCs in a number of high-use products, the District

proposes amendments to Rule 1020 (Definitions) to add DMC and PC to the District’s 

list of exempt VOCs. 

Previous District actions similarly amended Rule 1020 to exempt tertiary-butyl acetate 

(TBAc) and methyl formate (MF) as a result of EPA actions exempting such 

compounds. The previous District actions set a limit for use of TBAc and MF at one 

gallon per year per facility; use above that threshold currently requires the operator to 

get a Permit to Operate (PTO). During the evaluation and risk assessment for the 

current action (exemption of DMC and PC), District staff determined that the one-gallon 

threshold for TBAc and MF is redundant and unnecessary given the Risk Management 

Review required by District Rules 2201 (New and Modified Stationary Source Review) 

and 2020 (Exemptions) for all compounds with potential risk, especially cumulative risk 

of compounds that, by themselves, are below the District’s significance threshold. 

Therefore, the proposed amendments to Rule 1020 (Definitions) include deletion of the 

TBAc and MF use limitations to reduce redundancy and improve clarity.

IV. DISCUSSION 

The District received a request from Kowa American Corporation (Kowa) to amend Rule 

1020 (Definitions) to include DMC and PC as exempt VOCs, as defined in Section 3.53 

in the rule. In July 2004, Kowa petitioned the federal government to exempt DMC as a 

VOC. EPA approved the exemption of DMC and PC as VOCs in 2009 (see Appendix 

B) after several years of evaluation of the ozone-reducing values and environmental, 

toxicity, and safety profiles of these compounds. 
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Section 3.53 of Rule 1020 defines VOCs and lists compounds that are both organic and 

volatile, yet are considered by the District to have a low potential to form ozone, thus 

making them exempt from regulatory requirements. One of the proposed amendments

to Rule 1020 changes the definition of VOC in Section 3.53 to add DMC and PC to the 

list of exempt compounds. By exempting DMC and PC, manufacturers of coatings or 

solvent cleaning materials have additional compounds with which to formulate low-VOC 

coatings and cleaning materials. 

Dimethyl Carbonate (DMC)

DMC is a colorless, fast-evaporating solvent with a substantial polar nature, i.e. it is 

water soluble. Manufacturers and suppliers of DMC expect it to be an effective 

replacement for esters, glycol ethers, and ketones in formulations. For some cleaning 

applications, DMC may be used to replace isopropyl alcohol, although DMC is less 

polar than isopropyl alcohol and therefore may not work as efficiently as isopropyl 

alcohol. In addition, DMC has solubility and other properties that might make it a 

replacement for trichloroethylene in solvent cleaning operations. 

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.

DMC may also replace some compounds such as xylene, toluene, MEK, and hexane,

which have been identified as toxic air contaminants by the ARB. Based on the 

following information and the risk assessment detailed below, the exemption of DMC as 

a VOC is not expected to pose a significant health risk to Valley residents if substituted 

for a non-exempt VOC at District-regulated stationary sources.

Given that the most likely application of DMC is as a replacement in coatings or as a 

cleaning solvent, inhalation is expected to be the primary pathway of human exposure 

due to evaporation of the solvent. 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 is limited to accidental ingestion.

Data from Kowa American, the manufacturer of this chemical, indicates that once DMC

enters the body, it can be converted into methanol and carbon dioxide. The California 

Office of Environmental Health Hazard Assessment (OEHHA) conducted an 

assessment of the health effects of exposure to DMC. No data is available in the peerreviewed literature for chronic exposure of humans to DMC. However, one teratology 
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study conducted by Exxon in 1992 indicates maternal and developmental toxicity on 

mice when exposed to high (3,000 ppmv) inhalation exposure levels. No observed 

effects were reported at 1,000 ppmv exposure level. These results are consistent with 

the studies of the inhalation of methanol. 

There are no data available on the chronic effects or carcinogenicity of DMC. Since so 

little toxicity information on DMC itself is available, the toxicity of methanol was used to 

develop risk screening values for DMC. The OEHHA-proposed interim acute screening 

value of 18,000 mg/m3 and chronic screening value of 5,500 mg/m3 are expected to be 

protective of anticipated adverse health effects, including the developmental toxicity 

observed in the Exxon study noted above. The OEHHA evaluation is attached as

Appendix C.

No exposure guidelines have been established for DMC by the Occupational Safety and 

Health Agency (OSHA), the American Conference of Industrial Hygienists (ACGIH), or 

the National Institute for Occupational Safety and Health (NIOSH). However, Kowa 

American recommends an occupational exposure level of 200 ppmv over an 8-hour 

period based on the exposure limit established by OSHA and ACGIH for methanol, one 

of the chemicals to which the body converts DMC. This exposure level limit is in line 

with other solvents that DMC would replace.

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 

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 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.

The District’s Risk Management Policy for Permitting New and Modified Sources 

requires assessment of risks from toxic air contaminants (TAC). While DMC is not 

classified as a TAC, there are minor acute and chronic risks, as noted above, which 

require acknowledgement and assessment per District policy, especially the cumulative 

effect that such compounds have when combined with other compounds with potential 

risk. Given the thorough and cumulative requirements of the District’s risk management 

policy, any use of DMC, or any other exempt VOC with known toxicity levels (and 

established Reference Exposure Level [REL] or screening levels), will be assessed and 

mitigated during the permitting process to ensure that the cumulative risk is below a

hazard index of 1.0, which is the District’s significance threshold.

Given the anticipated uses of DMC (solvents in coatings, adhesives, or sealants), there 

are potential uses that would not require permitting because of the amount of product 
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used, and therefore may not be subject to the District’s risk management policy and 

assessment. Rule 2020 (Exemptions), Section 6.8 (Surface Coating Operations) 

exempts “architectural surface coatings used for commercial or residential applications.” 

Such coatings are regulated by ARB as consumer products and are not normally

considered by the District. Similarly, worker exposure issues are the purview of the 

California OSHA. Surface coating operations, which are regulated by the District as a 

stationary source, are allowed to use, without permit, less than one quart of coating 

(which may contain DMC as a solvent or thinner) per day or less than eight gallons of 

coating per year within their facility. Therefore, the District’s health risk assessment for 

this rule amendment is focused on these potentially unpermitted uses. 

The District used AERMOD (a modeling program of EPA’s Agency Regulatory Model 

Improvement Committee [AERMIC]) to determine the worst-case dispersion factors for 

emissions from a stationary source using a coating containing an exempt VOC. For 

comparison purposes, the District also evaluated other recently exempted VOCs—TBAc 

and MF—in addition to DMC. Staff selected coatings (containing VOCs) to analyze

based on information in ARB’s Draft Report on the 2005 Architectural Coatings Survey

and include a solvent-based coating with 47% VOC content (by weight) and a waterbased coating with 5% VOC content. Initially, staff evaluated four different scenarios for 

emissions from these coatings: urban dispersion from a volume source, rural dispersion 

from a volume source, dispersion from a spray booth with an uncapped stack, and 

dispersion from a spray booth with a capped stack. For all VOCs evaluated, the rural 

dispersion from a volume source using the solvent-based coating resulted in the highest 

acute, chronic, and cancer risk estimates given the exemption limits in Rule 2020—one 

quart per day for acute risk (assuming that the entire quart was used in one hour) and 

eight gallons per year for chronic and cancer risk. Table 1 summarizes the results from 

this worst-case scenario. 

Table 1 – Risk Estimates for Exemption Use of DMC, MF, and TBAc

Compound

47% VOC in Solvent-Based Coating

Acute Risk

1 Quart in 1 Hour

Chronic Risk

8 Gallons in 1 Year

Cancer Risk

8 Gallons in 1 Year

Dimethyl Carbonate (DMC) 0.52 0.002051 N/A

Methyl Formate (MF) 0.67 N/A N/A

tertiary-Butyl Acetate (TBAc) 0.39 N/A 3.01E-06

N/A indicates no risk exposure limits or screening values exist for the associated risk and compound.

The details of this analysis are included as Appendix D to this staff report.

Based on this analysis, an unpermitted source using any of the three compounds in 

reasonably anticipated ways would not pose an unacceptable risk. Furthermore, if 

usage rates of coatings containing these compounds exceed the limits in Rule 2020, a 

permit would be required, which would require a thorough and cumulative risk 
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management review for all operations that require a permit and would regulate 

individual project risk as part of the permitting process.

Methyl Formate (MF) and Tertiary-Butyl Acetate (TBAc)

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. 

 

Propylene Carbonate (PC)

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, lip liner, deodorant, anti-aging creams, and concealers. Other known 

applications of PC include special-purpose lubricant, general-purpose degreasers for 

industrial use, rubberized coatings, and non-flat 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.

Table 2 summarizes the physical and chemical properties of the compounds DMC and 

PC might replace.
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Table 2 – Comparison of Currently-Used Solvents, Dimethyl Carbonate and Propylene Carbonate

Property Acetone Ethylene

Glycol

Isopropyl 

Alcohol Methyl Acetate Methyl EthylKetone

Dimethyl

Carbonate

Propylene 

Carbonate

Appearance Colorless clear 

liquid

Colorless clear 

liquid

Clear colorless 

liquid

Colorless clear 

liquid

Colorless clear 

liquid

Clear colorless 

liquid

Colorless clear 

liquid

Odor Ethereal Odorless Rubbing 

alcohol Fragrance like Sharp mint-like odor Pleasant odor Odorless

Molecular Formula C3H6O HOCH2

CH2OH (CH3)2CHOH CH3COOCH3 CH3COCH2 CH3 (CH3)2CO3 C4H6O3

Molecular Weight 58.08 g/mole 62.07 g/mole 60.09 g/mole 74.08 g/mole 72.11 g/mole 90.08 g/mole 102.09 g/mol

Density 2 g/mL 2.14 g/mL 2.1 g/mL 2.8 g/mL 2.5 g/mL 1.07 g/mL 1.25 g/mL

Boiling Point 56.2 °C 197.6 °C 82 °C 57 °C 80 °C 90 °C 242 °C

Melting Point -95.35 °C -13 °C -89 °C -98.05 °C -86 °C 2 °C -49.2 °C

Vapor Pressure 180 mmHg @ 

20 °C

0.06 mmHg @ 

20 °C

44 mmHg 

@ 25 °C

173 mmHg 

@ 20 °C

78 mmHg 

@ 20 °C

55 mmHg

@ 25 °C

0.02 mmHg 

@ 20 °C

Solubility in Water Soluble Soluble Miscible Soluble Soluble Soluble 1-10%

Solvent Solubility Not available Slightly soluble Not available

Easily soluble in 

methanol, diethyl 

ether

Miscible with most 

organic solvents

Miscible with most 

organic solvents Not available

NFPAA Flammability 

Rating 3 1 3 3 3 3 1

Lower Explosive 

Limit 2.5% 3.2% 2.0% 3.1% 1.4% 4.2% 1.21%

Upper Explosive 

Limit 12.8% 36% 12.7% 16% 11.4% 12.9% 5.35%

Flash Point -20 °C 111 °C 12 °C -10 °C -9 °C 18 °C 132 °C A

 National Fire Protection Agency B

 Based on methanol as surrogate C

 OEHHA/ARB Approved Risk Assessment Health Values D

 Permissible Exposure Level
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Table 2 (continued) – Comparison of Currently-Used Solvents to Dimethyl Carbonate and Propylene Carbonate

Property Acetone Ethylene

Glycol

Isopropyl 

Alcohol Methyl Acetate Methyl EthylKetone

Dimethyl

Carbonate

Propylene 

Carbonate

OSHA PEL D 1,000 ppmv None 400 ppmv 200 ppmv 200 ppmv 200 ppmv B,C None

Acute Inhalation 

REL None None 3,200 ug/m3 None 18,000 ug/m3 18,000 ug/m3 B,C None

Chronic Inhalation 

REL None 400 ug/m3 7,000 ug/m3 None None 5,000 ug/m3 B,C None

Carcinogenic No No No No No No No

A

 National Fire Protection Agency B

 Based on methanol as surrogate C

 OEHHA/ARB Approved Risk Assessment Health Values D

 Permissible Exposure Level
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V. GLOBAL CLIMATE CHANGE AND GREENHOUSE GASES

The California Global Warming Solutions Act of 2006 (AB 32) created a comprehensive, 

multi-year program to reduce greenhouse gas (GHG) emissions in California, with the 

overall goal of restoring emissions to 1990 levels by the year 2020. In the coming 

years, ARB and the Legislature will be developing policies and programs to implement 

AB 32. The District believes that the evidence and the rationale that climate change is 

occurring is compelling and convincing. In addition to the long-term consequences of 

climate change, the District is concerned with the potential ramifications of more 

moderate but imminent changes in weather patterns. The Valley depends heavily on 

agriculture for its economy and has developed agricultural practices based on the last 

several decades of weather patterns. Unanticipated and large fluctuations in these 

patterns could have a devastating effect on the Valley’s economy.

While there are many win-win strategies that can reduce both GHG and criteria/toxic 

pollutant emissions, when faced with situations that involve tradeoffs between the two, 

District staff believes that the more immediate public health concerns that may arise 

from an increase in criteria or toxic pollutant emissions should take precedence. The 

District’s Governing Board adopted the Climate Change Action Plan (CCAP) in August 

2008. For California Environmental Quality Act (CEQA) requirements, one of the goals 

of the CCAP is to establish District processes for assessing the significance of 

greenhouse gas impacts. The District has developed a policy and guidance for 

addressing greenhouse gases under CEQA. 

VI. ANALYSES

A. Emission Reduction Analysis 

Some manufacturers have expressed interest in replacing current coating solvents with 

these compounds, and emissions reductions would be expected from any VOCcontaining 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.

B. 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. 

C. 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 
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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.

D. Environmental Impact Analysis

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 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 

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.

E. 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.

VII. REFERENCES

Air Quality: Revision to Definition of Volatile Organic Compounds--Exclusion of 

Propylene Carbonate and Dimethyl Carbonate, 74 Fed. Reg. 12, pp. 3437–3441. 

(2009, January 21). (to be codified at 40 CFR Part 51). 

California Office of Environmental Health Hazard Assessment [OEHHA]. (2012, 

February 16). Memorandum: Screening Values for Dimethyl Carbonate.
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Appendix A: Comments and Responses February 21, 2013

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APPENDIX A

SUMMARY OF SIGNIFICANT COMMENTS AND RESPONSES FOR 

PROPOSED AMENDMENTS TO RULE 1020

February 21, 2013
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SUMMARY OF SIGNIFICANT COMMENTS AND RESPONSES TO 

PROPOSED AMENDMENTS TO RULE 1020 FOR THE COMMENT PERIOD ENDING 

FEBRUARY 5, 2013

Stakeholders submitting comments:

American Coatings Association (ACA)

COMMENT: ACA supports the proposed amendments to Rule 1020.

RESPONSE: Comment noted.
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SUMMARY OF SIGNIFICANT COMMENTS AND RESPONSES TO 

DRAFT RULE 1020 DATED NOVEMBER 18, 2010

EPA Region IX Staff Comments:

EPA Region IX staff has reviewed the draft amendments and indicated, via e-mail, that 

because the amendments are consistent with the EPA VOC definition they have no 

comments.

California Air Resources Board (ARB) Comments

1. COMMENT: The Air Resources Board is conducting indoor health assessments

to estimate likely indoor exposures to DMC during realistic but high-exposure 

conditions. Since DMC may be used in paints and solvents, we are estimating 

exposures from painting a small, residential bathroom as well at auto repair 

shops. ARB expects to complete the assessment and send an advisory memo 

on DMC to California Air Pollution Control Officers Association (CAPCOA) next 

month (January 2011). The rule project should be delayed until the advisory 

memo is publicly available and the District has the opportunity to evaluate the 

memo’s conclusions.

RESPONSE: The District delayed the rule project and reviewed ARB’s analysis. 

ARB’s analysis related to consumer use of architectural coatings, which is

outside the District’s regulatory jurisdiction. ARB did not propose any action with 

regard to state-wide exemption of DMC. For this reason, the District is 

proceeding with the proposed amendments to Rule 1020 to exempt DMC 

consistent with the EPA ruling in 2009. The District will evaluate the use and risk 

of DMC at stationary sources consistent with its Risk Management Policy for 

Permitting New and Modified Sources.

Stakeholders submitting comments:

American Coatings Association (ACA)

Kowa American Corporation (KAC)

LyondellBasell Industries (LBI)

2. COMMENT: The coatings industry is under constant pressure to reformulate 

products to lower and lower VOC content. As a result there is a critical and 

urgent need for safe, effective and affordable exempt solvents and coating 

formulators need all available tools to formulate both lower VOC and reactivity 

coatings. As such, dimethyl carbonate and propylene carbonate should be 

added to the list of exempt compounds without any restrictions since these 

compounds were exempted by the US EPA, nearly every state in US and 
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many California Air Districts based on their negligible contribution to 

tropospheric ozone formation. (ACA, LBI)

RESPONSE: Comment noted. Please refer to the Final Staff Report for 

language supporting the District’s decision to amend Rule 1020.

3. COMMENT: Kowa American fully agrees with the proposed VOC exemption rule 

as written and strongly urges that the rule be adopted as soon as possible. We 

feel DMC being VOC exempt will allow your local businesses a much greater 

degree of flexibility in meeting the more stringent VOC restrictions. We also think 

that with the increasingly strict VOC regulations that having additional VOC 

exempt solvents is a form of regulatory relief that your constituents will welcome. 

(KAC)

RESPONSE: Additional technical information about this chemical originally 

provided with this comment has been evaluated and incorporated into the Final 

Staff Report as appropriate.

4. COMMENT: DMC should be subject to the same Authority to Construct (ATC)

and Permit-to-Operate (PTO) requirements as methyl formate since the two 

chemicals share the common metabolite methanol. (LBI)

RESPONSE: The proposed amendments to Rule 1020 reflect the deletion of 

use limits requiring and ATCs and PTOs for methyl formate.

5. COMMENT: ATC and PTO requirements should be removed for tertiary butyl 

acetate (TBAc) since new scientific evidence on tertiary butyl alcohol and TBAc

and expert opinions confirm that neither compound poses a cancer risk to 

humans. (LBI)

RESPONSE: The proposed amendments to Rule 1020 reflect the deletion of use 

limits requiring and ATCs and PTOs for TBAc.
SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Comments and Responses February 21, 2013

A-6 Final Staff Report with Appendices

For Proposed Amendments to Rule 1020

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SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix B: Federal Register Announcement February 21, 2013

B-1 Final Staff Report with Appendices

For Proposed Amendments to Rule 1020

APPENDIX B

FEDERAL REGISTER ANNOUNCEMENT OF USEPA EXEMPTING 

DIMETHYL CARBONATE AND PROPYLENE CARBONATE

February 21, 2013
SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix B: Federal Register Announcement February 21, 2013

B-2 Final Staff Report with Appendices

For Proposed Amendments to Rule 1020

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Federal Register / Vol. 74, No. 12 / Wednesday, January 21, 2009 / Rules and Regulations 3437 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 51 

[EPA–HQ–OAR–2006–0948; FRL–8763–7] 

RIN 2060–AN75 

Air Quality: Revision to Definition of 

Volatile Organic Compounds— 

Exclusion of Propylene Carbonate and 

Dimethyl Carbonate 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: This action revises EPA’s 

definition of volatile organic 

compounds (VOCs) for purposes of 

preparing state implementation plans 

(SIPs) to attain the national ambient air 

quality standard for ozone under Title I 

of the Clean Air Act (Act). This revision 

adds the compounds propylene 

carbonate and dimethyl carbonate to the 

list of compounds which are excluded 

from the definition of VOC on the basis 

that these compounds make a negligible 

contribution to tropospheric ozone 

formation. 

DATES: This final rule is effective on 

February 20, 2009. 

ADDRESSES: The EPA has established a 

docket for this action under Docket ID 

No. EPA–HQ–OAR–2006–0948. All 

documents in the docket are listed on 

the http://www.regulations.gov Web 

site. Although listed in the index, some 

information is not publicly available, 

i.e., confidential business information 

(CBI) or other information whose 

disclosure is restricted by statute. 

Certain other material, such as 

copyrighted material, will be publicly 

available only in hard copy. Publicly 

available docket materials are available 

either electronically in http:// 

www.regulations.gov or in hard copy at 

the Docket ID No. EPA–HQ–OAR–2006– 

0948, EPA/DC, EPA West, Room 3334, 

1301 Constitution Avenue, Northwest, 

Washington, DC. The Public Reading 

Room is open from 8:30 a.m. to 4:30 

p.m., Monday through Friday, excluding 

legal holidays. The telephone number 

for the Public Reading Room is (202) 

566–1744, and the telephone number for 

the Docket ID No. EPA–HQ–OAR–2006– 

0948 is (202) 566–1742. 

FOR FURTHER INFORMATION CONTACT: 

William L. Johnson, Office of Air 

Quality Planning and Standards, Air 

Quality Policy Division, Mail code 

C539–01, Research Triangle Park, NC 

27711, telephone (919) 541–5245.; fax 

number: 919–541–0824; e-mail address: 

Johnson.WilliamL@epa.gov. 

SUPPLEMENTARY INFORMATION: 

I. General Information 

A. Does this action apply to me? 

You may be an entity affected by this 

policy change if you use or emit 

propylene carbonate or dimethyl 

carbonate. States which have programs 

to control VOC emissions will also be 

affected by this change. 

Category Examples of affected entities 

Industry .. Industries that make and use 

coatings, adhesives, inks or 

which perform paint stripping or 

pesticide application. 

States .... States that control VOC. 

This table is not intended to be 

exhaustive, but rather provides a guide 

for readers regarding entities likely to be 

affected by this action. This table lists 

the types of entities that EPA is now 

aware of that could potentially be 

affected by this action. Other types of 

entities not listed in the table could also 

be affected. If you have questions 

regarding the applicability of this action 

to a particular entity, consult the person 

listed in the preceding FOR FURTHER

INFORMATION CONTACT section. This 

action has no substantial direct effects 

on industry because it does not impose 

any new mandates on these entities, but, 

to the contrary, removes two chemical 

compounds from the regulatory 

definition of VOC, and therefore from 

regulation for federal purposes. 

B. How is this preamble organized? 

The information presented in this 

preamble is organized as follows: 

Outline 

I. General Information 

A. Does this action apply to me? 

B. How is this preamble organized? 

II. Background 

A. Propylene Carbonate 

B. Dimethyl Carbonate 

III. Response to Comments 

IV. Final Action 

V. Statutory and Executive Order Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review 

B. Paperwork Reduction Act 

C. Regulatory Flexibility Act 

D. Unfunded Mandates Reform Act 

E. Executive Order 13132: Federalism 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

and Safety Risks 

H. Executive Order 13211: Actions That 

Significantly Affect Energy Supply, 

Distribution, or Use 

I. National Technology Transfer 

Advancement Act 

J. Executive Order 12848: Federal Actions 

To Address Environmental Justice in 

Minority Populations and Low-Income 

Populations 

K. Congressional Review Act 

II. Background 

Tropospheric ozone, commonly 

known as smog, occurs when VOCs and 

nitrogen oxides (NOX) react in the 

atmosphere. Because of the harmful 

health effects of ozone, EPA and state 

governments limit the amount of VOCs 

and NOX that can be released into the 

atmosphere. The VOCs are those organic 

compounds of carbon which form ozone 

through atmospheric photochemical 

reactions. Different VOCs have different 

levels of reactivity—that is, they do not 

react to form ozone at the same speed 

or do not form ozone to the same extent. 

Some VOCs react slowly, and changes 

in their emissions have limited effects 

on local or regional ozone pollution 

episodes. It has been EPA’s policy that 

organic compounds with a negligible 

level of reactivity should be excluded 

from the regulatory definition of VOC, 

so as to focus VOC control efforts on 

compounds that do significantly 

increase ozone concentrations. The EPA 

also believes that exempting such 

compounds creates an incentive for 

industry to use negligibly reactive 

compounds in place of more highly 

reactive compounds that are regulated 

as VOCs. The EPA lists these negligibly 

reactive compounds in its regulations 

(at 40 CFR 51.100(s)) and excludes them 

from the definition of VOCs. 

Since 1977, EPA has used the 

reactivity of ethane as the threshold for 

determining negligible reactivity. 

Compounds that are less reactive than, 

or equally reactive to, ethane under the 

assumed conditions may be deemed 

negligibly reactive. Compounds that are 

more reactive than ethane continue to 

be considered reactive VOCs and 

therefore subject to control 

requirements. The selection of ethane as 

the threshold compound was based on 

a series of smog chamber experiments 

that underlay the 1977 policy. 

In the past, EPA has considered three 

different metrics to compare the 

reactivity of a specific compound to that 

of ethane: (i) The reaction rate constant 

with the hydroxyl radical (known as 

kOH), (ii) maximum incremental 

reactivities (MIR) expressed on a 

reactivity per gram basis, and (iii) MIR 

expressed on a reactivity per mole basis. 

Table 1 presents these three reactivity 

metrics for ethane and for the two 

compounds discussed in this rule. 

Differences between these three metrics 

are discussed below. 


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1Basil Dimitriades, ‘‘Scientific Basis of an 

Improved EPA Policy on Control of Organic 

Emissions for Ambient Ozone Reduction.’’ Journal 

of the Air & Waste Management Association, 

49:831–838, July 1999. 

TABLE 1—REACTIVITIES OF ETHANE AND COMPOUNDS CONSIDERED FOR EXEMPTION

Compound kOH

(cm3/molecule-sec) 

MIR 

(g O3/mole VOC) 

MIR 

(g O3/gramVOC) 

Ethane .................................................................... 2.4 × 10¥13 ............................................................ 8.12 0 .27 

Propylene carbonate .............................................. 6.9 × 10¥13 ............................................................ 27.56 0 .27 

Dimethyl carbonate ................................................ 3.49 × 10¥13 .......................................................... 5.04 0 .056 

Notes: 

1. kOH value for ethane is from: R. 

Atkinson., D. L. Baulch, R. A. Cox, J. N. 

Crowley, R. F. Hampson, Jr., R. G. Hynes, M. 

E. Jenkin, J. A. Kerr, M. J. Rossi and J. Troe 

(2004), Summary of Evaluated Kinetic and 

Photochemical Data for Atmospheric 

Chemistry 

2. kOH value for propylene carbonate is 

reported in: W.P.L. Carter, D. Luo, I.L. 

Malkina, E.C. Tuazon, S.M. Aschmann, and 

R. Atkinson (July 8, 1996), ‘‘Investigation of 

the Atmospheric Ozone Formation Potential 

of t-butyl Alcohol, N-Methyl Pyrrolidinone 

and Propylene Carbonate.’’ University of 

California—Riverside. ftp://ftp.cert.ucr.edu/ 

pub/carter/pubs/arcorpt.pdf. 

3. kOH value for dimethyl carbonate is 

reported in: Y. Katrib, G. Deiber, P. Mirabel, 

S. LeCalve, C. George, A. Mellouki, and G. Le 

Bras (2002), ‘‘Atmospheric loss processes of 

dimethyl and diethyl carbonate,’’ J. Atmos. 

Chem., 43: 151–174. 

4. All maximum incremental reactivities or 

MIR (g O3/g VOC) values are from: W. P. L. 

Carter, ‘‘Development of the SAPRC–07 

Chemical Mechanism and Updated Ozone 

Reactivity Scales,’’ Appendix B, July 7, 2008. 

This may be found at http:// 

www.engr.ucr.edu/∼carter/SAPRC/ 

saprc07.pdf. These values have been revised 

slightly from those given in the proposal 

notice (72 FR 55717). 

5. MIR (g O3/mole VOC) values were 

calculated from the MIR (g O3/g VOC) values 

by determining the number of moles per 

gram of the relevant organic compound. 

The kOH is the reaction rate constant 

of the compound with the OH radical in 

the air. This reaction is typically the 

first step in a series of chemical 

reactions by which a compound breaks 

down in the air and participates in the 

ozone forming process. If this step is 

slow, the compound will likely not form 

ozone at a very fast rate. The kOH values 

have long been used by EPA as a 

measure of photochemical reactivity 

and ozone forming activity, and they 

have been the basis for most of EPA’s 

previous exclusions of negligibly 

reactive compounds. The kOH metric is 

inherently molar, i.e., it measures the 

rate at which molecules react. 

The MIR values, both by mole and by 

mass, are more recently developed 

measures of photochemical reactivity 

derived from a computer-based 

photochemical model. These measures 

consider the complete ozone forming 

activity of a compound, not merely the 

first reaction step. Further explanation 

of the MIR metric can be found in: W. 

P. L. Carter, ‘‘Development of Ozone 

Reactivity Scales for Volatile Organic 

Compositions,’’ Journal of the Air & 

Waste Management Association, Vol 44, 

881–899, July 1994. 

The MIR values are usually expressed 

either as grams of ozone formed per 

mole of VOC (molar basis) or as grams 

of ozone formed per gram of VOC (mass 

basis). For comparing the reactivities of 

two compounds, using the molar MIR 

values considers an equal number of 

molecules of the two compounds. 

Alternatively, using the mass MIR 

values compares an equal mass of the 

two compounds, which will involve 

different numbers of molecules, 

depending on the relative molecular 

weights. The molar MIR comparison is 

consistent with the original smog 

chamber experiments, which compared 

equal molar concentrations of 

individual VOCs, that underlie the 

original selection of ethane as the 

threshold compound. It is also 

consistent with previous reactivity 

determinations based on inherently 

molar kOH values. The mass MIR 

comparison is consistent with how MIR 

values and other reactivity metrics are 

applied in reactivity-based emission 

limits, specifically the California Air 

Resources Board rule for aerosol 

coatings (see http://www.arb.ca.gov/ 

consprod/regs/apt.pdf ). 

Given the relatively low molecular 

weight of ethane, use of the mass basis 

tends to result in more VOCs falling into 

the ‘‘negligibly reactive’’ class versus 

the molar basis. This means that, in 

some cases, a compound might be 

considered less reactive than ethane and 

eligible for VOC exemption under the 

mass basis but not under the molar 

basis. One of the compounds considered 

in this action falls into this situation, 

where the molar MIR value is greater 

than that of ethane, but the mass MIR 

value is less than or equal to that of 

ethane. This compound is propylene 

carbonate. 

The EPA has considered the choice 

between a molar or mass basis for the 

comparison to ethane in past 

rulemakings and guidance. The design 

of the VOC exemption policy, including 

the choice between a mass and mole 

basis, has been critiqued in the 

published literature.1 Most recently, in 

‘‘Interim Guidance on Control of 

Volatile Organic Compounds in Ozone 

State Implementation Plans’’ published 

on September 13, 2005 (70 FR 54046), 

EPA stated: 

‘‘* * * a comparison to ethane on a mass 

basis strikes the right balance between a 

threshold that is low enough to capture 

compounds that significantly affect ozone 

concentrations and a threshold that is high 

enough to exempt some compounds that may 

usefully substitute for more highly reactive 

compounds. * * * When reviewing 

compounds that have been suggested for 

VOC exempt status, EPA will continue to 

compare them to ethane using kOH expressed 

on a molar basis and MIR values expressed 

on a mass basis.’’ 

Relying on a comparison of mass MIR 

values consistent with this guidance, 

EPA proposed to revise its definition of 

VOC at 40 CFR 51.100(s) to add 

propylene carbonate and dimethyl 

carbonate to the list of compounds that 

are exempt because they are negligibly 

reactive since they are equal to or less 

reactive than ethane on a mass basis. 

For propylene carbonate, EPA invited 

comment on the alternative use of a 

molar basis for the comparison of these 

compounds to ethane. 

The technical rationale for 

recommending an exemption for each of 

the individual compounds is given 

below: 

A. Propylene Carbonate 

Huntsman Corporation submitted a 

petition to EPA on July 27, 1999, 

requesting that propylene carbonate be 

exempted from VOC control based on its 

low reactivity relative to ethane. 

Propylene carbonate (CAS registry 

number 108–32–7) is an odorless nonviscous clear liquid with a low vapor 

pressure (0.023 mm Hg at 20( C) and 

low evaporation rate compared to many 

other commonly used organic solvents. 

It has been used in cosmetics, as an 

adhesive component in food packaging, 

as a solvent for plasticizers and 

synthetic fibers and polymers, and as a 

solvent for aerial pesticide application. 


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2The MIR values used for this rule may be found 

in Appendix B of the July 7, 2008 report by William 

P.L. Carter ‘‘Development of the SAPRC–07 

Chemical Mechanism and Updated Ozone 

Reactivity Scales.’’ This report may be found at 

http://www.engr.ucr.edu/carter/SAPRC/saprc07.pdf 

or in the docket for this rule. 

Huntsman submitted several pieces of 

information to support its petition, all of 

which have been added to the docket for 

this action. One of these pieces of 

information was ‘‘Investigation of the 

Atmospheric Ozone Formation Potential 

of t-butyl Alcohol, N-Methyl 

Pyrrolidinone and Propylene 

Carbonate’’ by William P. L. Carter, 

Dongmin Luo, Irina L. Malkina, Ernesto 

C. Tuazon, Sara M. Aschmann, and 

Roger Atkinson, University of California 

at Riverside, July 8, 1996. Table 8 of that 

reference lists the MIR for propylene 

carbonate (on a gram basis) as 1.43 times 

higher than that of ethane. However, in 

Table 1 above, EPA has shown a 2007 

MIR value that was taken from more 

recent 2007 data from Dr. Carter’s Web 

site. This 2007 MIR value is lower than 

that of ethane on a mass basis. 

From the data in Table 1, it can be 

seen that propylene carbonate has a 

higher kOH value than ethane, meaning 

that it initially reacts more quickly in 

the atmosphere than ethane. A molecule 

of propylene carbonate is also more 

reactive than a molecule of ethane, as 

shown by the molar MIR (g O3/mole 

VOC) values, since equal numbers of 

moles have equal numbers of molecules. 

However, a gram of propylene carbonate 

is less reactive, or creates less ozone on 

the day of its emission to the 

atmosphere, than a gram of ethane. This 

is because propylene carbonate has a 

molecular weight (102), which is over 

three times that of ethane (30), thus 

requiring less than a third the number 

of molecules of propylene carbonate to 

weigh a gram than the number of 

molecules of ethane needed to weigh a 

gram. 

Based on the mass MIR (g O3/g VOC) 

value for propylene carbonate being 

equal to or less than that of ethane, EPA 

finds that propylene carbonate is 

‘‘negligibly reactive’’ and therefore 

exempt for the regulatory definition of 

VOC at 40 CFR 51.100(s). EPA took 

comments on whether the comparison 

of propylene carbonate to ethane should 

instead be made on the basis of the 

molar MIR (g O3/mole VOC) value. None 

of the comments received during the 

public comment period opposed using 

the g O3/g VOC basis. In fact, the 

comments which addressed that issue 

supported the use of the MIR on a g O3/ 

g VOC basis for granting exemptions. 

B. Dimethyl Carbonate 

The EPA received a petition from 

Kowa America Corporation on July 29, 

2004 seeking an exemption from the 

regulatory definition of VOC for 

dimethyl carbonate. This petition 

asserted that dimethyl carbonate (DMC) 

is less photochemically reactive than 

ethane and asked for the exemption on 

that basis. 

Dimethyl carbonate (CAS registry 

number 616–38–6) may be used as a 

solvent in paints and coatings. The 

petitioner anticipated that it might be 

used in waterborne paints and 

adhesives because it is partially water 

soluble. It is also used as a methylation 

and carbonylation agent in organic 

synthesis. It can be used as a fuel 

additive. 

In support of its petition, the 

petitioner presented articles which give 

kOH and MIR values for the compound. 

These articles have been placed in the 

docket. 

As shown in Table 1, DMC has a 

greater kOH value than ethane, which 

indicates that DMC will likely initially 

react more quickly in the atmosphere. 

However, the MIR values for DMC 

calculated on either a mass or mole 

basis are less than that of ethane, which 

indicates lower reactivity overall. Based 

on these data, EPA finds that DMC is 

‘‘negligibly reactive’’ and therefore 

exempt from the regulatory definition of 

VOC at 40 CFR 51.100(s). Because both 

the mass and molar MIR values of DMC 

are less than those of ethane, this 

chemical meets EPA’s exemption 

criteria under either MIR metric. 

III. Response to Comments 

EPA proposed these actions on 

October 1, 2007 (72 FR 55717) and took 

public comment on the proposal. Here 

is a summary of the comments received 

during the public comment period and 

EPA’s response. There was no request 

for a public hearing on the proposal and 

none was held. 

There were four comment letters 

submitted to the docket during the 

public comment period. One comment 

letter was from an individual. Two were 

from chemical companies. One 

comment letter was from a trade 

association. The comments are 

summarized below. 

Comment: The Web site reference for 

the latest MIR values contained an error. 

The site which was listed as http:// 

pah.cert.ucr.edu/carter/SAPRC/ 

scales07.xls should have been http:// 

pah.cert.ucr.edu/∼carter/SAPRC/ 

scales07.xls. 

Response: We left out the ∼ sign in the 

Web address which made it incorrect. 

The latest MIR data which is used in 

this final rule may be found in 

Appendix B of the July 7, 2008 report 

by William P. L. Carter ‘‘Development of 

the SAPRC–07 Chemical Mechanism 

and Updated Ozone Reactivity Scales.’’ 

This report may be found at http:// 

www.engr.ucr.edu/∼carter/SAPRC/ 

saprc07.pdf. 

Comment: One commenter corrected 

certain technical information about the 

evaporation rate of dimethyl carbonate 

which was listed in the docket. 

Response: This correction is noted, 

but this minor change did not impact 

whether or not EPA should finalize the 

exemption petition. 

Comment: One commenter supported 

the use of the latest MIR values for 

making VOC exemption determinations. 

There were no comments opposing the 

use of the latest MIR values. 

Response: EPA acknowledged recent 

MIR values which were made public 

shortly before the proposal to grant VOC 

exemption to propylene carbonate and 

dimethyl carbonate, but based the 

proposal on older MIR values which 

had been previously published. EPA is 

using the latest MIR values for this final 

rule.2 The use of the newer MIR values 

does not change the conclusion about 

the VOC exemption of propylene 

carbonate and dimethyl carbonate. 

Comment: The two industry 

commenters, and the trade association 

comment letter each expressed support 

for the VOC exemption of propylene 

carbonate and dimethyl carbonate. 

Response: EPA acknowledges this 

support and notes that there were no 

comments opposing these exemptions. 

Comment: Three commenters 

opposed separate tracking and reporting 

for propylene carbonate and dimethyl 

carbonate. Two of these commenters 

also expressed opposition for separate 

tracking for any VOC exempt 

compounds. 

Response: Although the rule preamble 

encourages record keeping for 

propylene carbonate and dimethyl 

carbonate, there is no requirement for 

this in the rule itself. Record keeping for 

other exempt compounds is not the 

subject of this rulemaking, so comments 

about that are not relevant to this action. 

Comment: Three of the commenters 

support the use of the mass-based MIR 

approach versus the mole-based 

approach. One of the commenters 

submitted as part of his comments a 

November 15, 1999 letter written by 

William P.L. Carter supporting the use 

of impact per mass as an appropriate 

basis for comparing ozone reactivities 

when making VOC exemption 

decisions. This Carter letter had 

previously been submitted to EPA as 

part of the tertiary butyl acetate VOC 

exemption rule making (69 FR 69298). 


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There were no comments opposing the 

use of the mass-based MIR approach. 

Response: EPA specifically requested 

comment on this subject for propylene 

carbonate since the mole based MIR 

value for that compound is higher than 

that of ethane and using the mole based 

MIR value would not allow the 

exemption for propylene carbonate. 

Because there were no comments 

opposed to the use of the mass based 

approach, EPA is proceeding to grant 

these exemptions on a mass based MIR 

basis in keeping with the September 13, 

2005 interim guidance on control of 

volatile organic compounds in ozone 

state implementation plans which says 

‘‘EPA will continue to compare them 

[i.e., compounds] to ethane using kOH

expressed on a molar basis and MIR 

values expressed on a mass basis.’’ 

Comment: One commenter, who was 

the petitioner for dimethyl carbonate, 

said that the company recommended 

exposure limit of 200 ppm time 

weighted average 8 hour for dimethyl 

carbonate is identical to that of methyl 

acetate, an existing VOC exempt 

solvent. This commenter also said that 

methyl acetate like DMC has the 

potential for hydrolyzing to form 

methanol in the body and therefore they 

would be similar in their toxicity 

profiles and safety handling 

requirements. The commenter also 

denied a statement in Hawley’s 

Condensed Chemical Dictionary that 

DMC is both toxic by inhalation and a 

strong irritant. 

Response: In the proposal, EPA said 

‘‘While EPA does not have information 

to suggest that the proposed exemptions 

could increase health risks due to 

possible toxicity of the exempted 

compounds, we invite the public to 

submit comments and additional 

information relevant to this issue.’’ The 

comments here are the only comments 

EPA received regarding health effects of 

these compounds. These comments 

have not led EPA to identify unusual 

health risks from the compounds. 

IV. Final Action 

This action is based on EPA’s review 

of the material in Docket ID No. EPA– 

HQ–OAR–2006–0948. The EPA hereby 

amends its definition of VOC at 40 CFR 

51.100(s) to exclude propylene 

carbonate and dimethyl carbonate from 

the regulatory definition of VOC for use 

in ozone SIPs and ozone controls for 

purposes of attaining the ozone national 

ambient air quality standard. 

The revised definition will also apply 

for purposes of any federal 

implementation plan for ozone 

nonattainment areas (see e.g., 40 CFR 

52.741(a)(3)). States are not obligated to 

exclude from control as a VOC those 

compounds that EPA has found to be 

negligibly reactive. However, if this 

action is made final, states should not 

include these compounds in their VOC 

emissions inventories for determining 

reasonable further progress under the 

Act (e.g., section 182(b)(1)) and may not 

take credit for controlling these 

compounds in their ozone control 

strategy. 

Excluding a compound from the 

regulatory definition of VOC may lead 

to changes in the amount of the exempt 

compound used and the types of 

applications in which the exempt 

compound is used. Although the final 

rule has no mandatory reporting 

requirements, EPA urges states to 

continue to inventory the emissions of 

these compounds for use in 

photochemical modeling. 

V. Statutory and Executive Order 

Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review 

This action is not a ‘‘significant 

regulatory action’’ under the terms of 

Executive Order 12866 (58 FR 51735, 

October 4, 1993) and is therefore not 

subject to review under the Executive 

Order. 

B. Paperwork Reduction Act 

This action does not impose any new 

information collection burden under the 

provisions of the Paperwork Reduction 

Act, 44 U.S.C. 3501 et seq. Burden is 

defined at 5 CFR 1320.3(b). This action 

is deregulatory in nature and removes 

requirements rather than adds 

requirements. The regulation is a rule 

change that revises a definition of 

volatile organic compound and imposes 

no record keeping or reporting 

requirements. 

C. Regulatory Flexibility Act 

The Regulatory Flexibility Act (RFA) 

requires an agency to prepare a 

regulatory analysis of any rule subject to 

notice and comment rulemaking 

requirements under the Administrative 

Procedure Act or any other statue unless 

the agency certifies that the rule will not 

have a significant economic impact on 

a substantial number of small entities. 

Small entities include small businesses, 

small organizations, and small 

governmental jurisdictions. 

For purposes of assessing the impacts 

of this action on small entities, small 

entity is defined as: (1) A small business 

as defined by the Small Business 

Administration’s (SBA) regulations at 13 

CFR 121.201); (2) a small governmental 

jurisdiction that is a government of a 

city, county, town, school district, or 

special district with a population of less 

than 50,000; and (3) a small 

organization that is any not-for-profit 

enterprise which is independently 

owned and operated and is not 

dominant in its field. 

After considering the economic 

impacts of this final action on small 

entities, I certify that this rule will not 

have a significant economic impact on 

a substantial number of small entities. 

This rule will not impose any 

requirements on small entities. This rule 

concerns only the definition of VOC and 

does not directly regulate any entities. 

The RFA analysis does not consider 

impacts on entities which the action in 

question does not regulate. See Motor & 

Equipment Manufacturers Ass’n v. 

Nichols, 142 F. 3d 449, 467 (D.C. Cir. 

1998); United Distribution Cos. v. FERC, 

88 F. 3d 1105, 1170 (D.C. Cir. 1996), 

cert. denied, 520 U.S. 1224 (1997). 

Pursuant to the provision of 5 U.S.C. 

605(b), I hereby certify that the rule will 

not have an impact on small entities. 

D. Unfunded Mandates Reform Act 

This action contains no federal 

mandates under the provisions of Title 

II of the Unfunded Mandates Reform 

Act of 1995 (UMRA), 2 U.S.C. 1531– 

1538 for state, local, and tribal 

governments and the private sector. 

Since this rule is deregulatory in nature 

and does not impose a mandate upon 

any source, this rule is not estimated to 

result in the expenditure by state, local 

and tribal governments or the private 

sector of $100 million in any 1 year. 

Therefore, the Agency has not prepared 

a budgetary impact statement or 

specifically addressed the selection of 

the least costly, most cost-effective, or 

least burdensome alternative. Because 

small governments will not be 

significantly or uniquely affected by this 

rule, the Agency is not required to 

develop a plan with regard to small 

governments. This action is also not 

subject to the requirements of section 

203 of the UMRA because it contains no 

regulatory requirements that might 

significantly or uniquely affect small 

governments. As discussed above, this 

final rule does not impose any new 

requirements on small governments. 

E. Executive Order 13132: Federalism 

Executive Order 13132, entitled 

‘‘Federalism’’ (64 FR 43255, August 10, 

1999), requires EPA to develop an 

accountable process to ensure 

‘‘meaningful and timely input by state 

and local officials in the development of 

regulatory policies that have federalism 

implications.’’ ‘‘Policies that have 

federalism implications’’ is defined in 


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the Executive Order to include 

regulations that have ‘‘substantial direct 

effects on the states, on the relationship 

between the national government and 

the states, or on the distribution of 

power and responsibilities among the 

various levels of government.’’ 

This final rule does not have 

federalism implications. It will not have 

substantial direct effects on the state, on 

the relationship between the national 

government and the states, or on the 

distribution of power and 

responsibilities among the various 

levels of government, as specified in 

Executive Order 13132. This rule 

concerns only the definition of VOC. 

Thus, Executive Order 13132 does not 

apply to this rule. 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

This rule does not have tribal 

implications, as specified in Executive 

Order 13175 (65 FR 67249, November 9, 

2000). It will not have substantial direct 

effects on tribal governments, on the 

relationship between the federal 

government and Indian Tribes, or on the 

distribution of power and 

responsibilities between the federal 

government and Indian Tribes, as 

specified in Executive Order 13175. 

This action does not have any direct 

effects on Indian Tribes. Thus, 

Executive Order 13175 does not apply 

to this rule. 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

and Safety Risks 

EPA interprets Executive Order 13045 

(62 FR 19885, April 23, 1997) as 

applying only to those regulatory 

actions that concern health or safety 

risks, such that the analysis required 

under section 5–501 of the Executive 

Order has the potential to influence the 

regulation. This final rule is not subject 

to Executive Order 13045 because it 

does not establish an environmental 

standard intended to mitigate health or 

safety risks. 

H. Executive Order 13211: Actions That 

Significantly Affect Energy Supply, 

Distribution, or Use 

This final rule is not a ‘‘significant 

energy action’’ as defined in Executive 

Order 13211 (66 FR 28355, May 22, 

2001), because it is not likely to have a 

significant adverse effect on the supply, 

distribution, or use of energy. Further, 

we have concluded that this rule is not 

likely to have any adverse energy 

effects. 

I. National Technology Transfer 

Advancement Act 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (‘‘NTTAA’’), Public Law 

104–113, section 12(d) (15 U.S.C. 272 

note) directs EPA to use voluntary 

consensus standards in its regulatory 

activities unless to do so would be 

inconsistent with applicable law or 

otherwise impractical. Voluntary 

consensus standards are technical 

standards (e.g., materials specifications, 

test methods, sampling procedures, and 

business practices) that are developed or 

adopted by voluntary consensus 

standards bodies. NTTAA directs EPA 

to provide Congress, through OMB, 

explanations when the Agency decides 

not to use available and applicable 

voluntary consensus standards. 

This action does not involved 

technical standards. Therefore, EPA did 

not consider the use of any voluntary 

consensus standards. 

J. Executive Order 12898: Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Populations 

Executive Order 12898 (59 FR 7629 

(Feb. 16, 1994)) establishes federal 

executive policy on environmental 

justice. Its main provision directs 

federal agencies, to the greatest extent 

practicable and permitted by law, to 

make environmental justice part of their 

mission by identifying and addressing, 

as appropriate, disproportionately high 

and adverse human health or 

environmental effects of their programs, 

policies, and activities on minority 

populations and low-income 

populations in the United States. 

EPA has determined that this final 

rule will not have disproportionately 

high and adverse human health or 

environmental effects on minority or 

low-income populations because it does 

not affect the level of protection 

provided to human health or the 

environment. The final rule amendment 

is deregulatory and does allow 

relaxation of the control measures on 

sources. However, this is not expected 

to lead to increased ozone formation 

since the compounds being exempted 

have been determined to have negligible 

photochemical reactivity. 

K. Congressional Review Act 

The Congressional Review Act, 5 

U.S.C. 801 et seq., as added by the Small 

Business Regulatory Enforcement 

Fairness Act of 1996, generally provides 

that before a rule may take effect, the 

agency promulgating the rule must 

submit a rule report, which includes a 

copy of the rule, to each House of 

Congress and to the Comptroller General 

of the United States, Section 804 

exempts form section 801 the following 

types of rules: (1) Rules of particular 

application; (2) rules relating to agency 

management or personnel; and (3) rules 

of agency organization, procedure, or 

practice that do not substantially affect 

the rights or obligations of non-agency 

parties, 5 U.S.C. 804(3). The EPA is not 

required to submit a rule report 

regarding this action under section 801 

because this is a rule of particular 

applicability to manufacturers and users 

of these specific exempt chemical 

compounds. This action is not a ‘‘major 

rule’’ as defined by 5 U.S.C. 804(2). 

Therefore, this rule will be effective on 

February 20, 2009. 

List of Subjects in 40 CFR Part 51 

Environmental protection, 

Administrative practice and procedure, 

Air pollution control, Ozone, Reporting 

and recordkeeping requirements, 

Volatile organic compounds. 

Dated: January 13, 2009. 

Stephen L. Johnson, 

Administrator. 

■ For reasons set forth in the preamble, 

part 51 of chapter I of title 40 of the 

Code of Federal Regulations is amended 

as follows: 

PART 51—REQUIREMENTS FOR 

PREPARATION, ADOPTION, AND 

SUBMITTAL OF IMPLEMENTATION 

PLANS 

■ 1. The authority citation for Part 51, 

Subpart F, continues to read as follows: 

Authority: 42 U.S.C. 7401, 7411, 7412, 

7413, 7414, 7470–7479, 7501–7508, 7601, 

and 7602. 

§ 51.100 [Amended] 

■ 2. Section 51.100 is amended at the 

end of paragraph (s)(1) introductory text 

by removing the words ‘‘and 

perfluorocarbon compounds which fall 

into these classes:’’ and adding in their 

place a semi-colon and the words 

‘‘propylene carbonate; dimethyl 

carbonate; and perfluorocarbon 

compounds which fall into these 

classes:’’. 

[FR Doc. E9–1150 Filed 1–16–09; 8:45 am] 

BILLING CODE 6560–50–P 


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APPENDIX C

OEHHA SCREENING VALUES FOR

DIMETHYL CARBONATE

February 21, 2013
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1

Dimethyl Carbonate 

(CAS# 616-38-6)

(Synonyms: Carbonic acid, methyl ester; methyl carbonate)

1 Introduction

Dimethyl carbonate has been used as a reagent in methylation reactions (HSDB, 2009), and has 

possible uses in paints, coatings, and adhesives. On January 13, 2009 the United States 

Environmental Protection Agency (U.S. EPA) granted a Volatile Organic Compound (VOC)

exemption to dimethyl carbonate (USEPA, 2009) since it makes a negligible contribution to 

tropospheric ozone formation. In a letter dated March 2, 2009, Kowa American submitted to the 

California Air Resources Board (ARB) an Application for VOC Exempt Status for dimethyl 

carbonate in California. The application contains limited toxicological information. As part of 

its consideration of exempt status for a VOC, ARB asked the Office of Environmental Health 

Hazard Assessment (OEHHA) to review the toxicology of dimethyl carbonate. 

Dimethyl carbonate does not have a Threshold Limit Value (TLV) for worker exposure. U.S. 

EPA also does not have any health values for exposure of the general public to dimethyl 

carbonate. OEHHA notes that increased public exposure is likely if dimethyl carbonate is 

exempted from VOC regulation, and its use becomes more widespread in California. There are 

insufficient data available for dimethyl carbonate to allow the development of Reference 

Exposure Levels (RELs) for dimethyl carbonate. Instead we used what data are available to us 

in developing acute and chronic screening values for dimethyl carbonate to compare to estimated 

exposures from use in California. Additionally, we discuss formation and toxicity of possible 

dimethyl carbonate metabolites.

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2 Physical and Chemical Properties of Dimethyl Carbonate (HSDB, 2009)

Description Colorless liquid; pleasant odor

Molecular formula C3-H6-O3

Molecular weight 90.08

Density 1.0636 @ 25oC/15oC

Boiling point 90-91oC

Melting point 0.5oC

Vapor pressure 55.364 mm Hg @ 25oC

Odor threshold Not found

Log Kow 0.23 (estimated) (Meylan and Howard, 1995;

 SRC, 2009)

Bioconcentration factor 3.16 (estimated) (Kowa American, 2009)

Solubility Miscible with alcohol and ether;

 Insoluble in water (HSDB, 2009);

 Solubility = 13.9 g/100 g water (Kowa American, 

 2009)

Flammability Highly flammable

Conversion factor 3.68 μg/m3 per ppb @ 25oC

3 Toxicity of Dimethyl Carbonate 

3.1 Metabolism of Dimethyl Carbonate

Dimethyl carbonate is readily hydrolyzed to carbon dioxide and methanol in the environment 

and presumably in the body via esterases (Kowa America, 2009). Methanol is metabolized to 

formaldehyde, which is then further oxidized to formic acid.

3.2 Animal Toxicity of Dimethyl Carbonate

The International Uniform Chemical Information Database (IUCLID) dataset (European 

Commission, 2000) indicates the following data gaps for dimethyl carbonate: chronic toxicity, 

genotoxicity, carcinogenicity, reproductive and developmental toxicity, neurotoxicity, 

immunotoxicity, aquatic toxicity, and toxicity to terrestrial organisms.

The IUCLID dataset lists a rat 4 hour LC50 of > 140 mg/L (> 38,000 parts per million (ppm)).

The IUCLID dataset reports that dimethyl carbonate is slightly irritating to the rabbit eye and not 

irritating to rabbit skin. No dose information is stated.

In a 10-day developmental toxicity study (Exxon, 1992; Bevan and Beyer, 1995), mated female 

CD-1 mice (96 per dose level) were exposed by inhalation to 0, 300, 1000, or 3000 ppm 

dimethyl carbonate during gestational days (gd) 6 through 15 for 6 h/day. The females were

euthanized on gd 18, and the fetuses from the first 30-32 pregnant dams were weighed, sexed, 

and examined for external, visceral, and skeletal alterations. Maternal body weights and body 

weight gains were significantly reduced at 3000 ppm (Table 1). 

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Table 1. Maternal body weights on gestation days 0, 15, and 18

Dimethyl

carbonate 0 ppm 300 ppm 1000 ppm 3000 ppm

Day 0 28.38±1.36 (32) 29.24±1.82 (31) 28.63±1.56 (30) 28.78±1.72 (32)

Day 15 43.47±2.60 (32) 43.03±3.66 (31) 42.80±2.54 (30) 39.23±3.55* (30)

Day 18 51.92±3.40 (30) 51.23±4.69 (30) 51.67±3.11 (30) 45.92±4.90* (30)

* p<0.01 vs. control. Values are mean ± 1 SD (number of dams)

Food consumption was significantly reduced at 1000 and 3000 ppm, indicating an adverse effect 

on the mothers. Gestational parameters affected at 3000 ppm included post-implantation loss due 

to increased resorptions, and altered sex ratio (fewer males surviving). Fetal body weights/litter 

were reduced at 3000 ppm indicating a gross adverse effect on the fetus (Table 2) and the 

number of growth-stunted fetuses (<1 g body weight) was increased.

Table 2. Fetal body weight as a function of dimethyl carbonate concentration

Dimethyl

carbonate

 

0 ppm

 

300 ppm

 

1000 ppm

 

3000 ppm

Males 1.24±0.10 (193) 1.27±0.12 (154) 1.24±0.10 (179) 1.12±0.14* (137)

Females 1.10±0.10 (157) 1.19±0.12 (181) 1.20±0.10 (155) 1.07±0.15* (140)

* p<0.01 vs. control. Values are mean ± 1 SD (number of fetuses)

Total incidences of fetal malformations were significantly increased at 3000 ppm and included 

cleft palate (Table 3), multiple malformations of the bones of the skull, and fused vertebral 

arches. Skeletal variations, including misshapen sternebrae (breastbones), rudimentary cervical 

ribs, and well-formed cervical or lumbar ribs, were also increased at 3000 ppm. The No 

Observed Adverse Effect Level (NOAEL) for maternal and developmental toxicity was 1000 

parts per million (ppm) (Exxon, 1992; Bevan and Beyer, 1995). In a developmental toxicity in 

mice, the NOAEL for inhaled methanol was also 1000 ppm (Rogers et al., 1993).

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Table 3. Some significantly increased external malformations

Dimethyl carbonate 0 ppm 300 ppm 1000 ppm 3000 ppm

Total fetuses (total litters) 350 (30) 337 (30) 334 (30) 277 (29)

External malformations

 Cleft palate 3 (2) 0 1 (1) 140 (26)**

 Microtia (small ear) 0 0 0 24 (5)*

 Low set ear(s) 0 0 0 13 (5)*

 Imperforate anus 0 0 0 5 (3)*

 Ectrodactyly# 0 0 0 4 (2)*

* p < 0.05 vs. control; ** p < 0.01 vs. control. Values are number of fetuses

 with malformations (number of litters affected).

# complete or partial absence of one or more digits

Song et al. (2002) tested three gasoline oxygenates, dimethyl carbonate, ethanol anhydrous, and 

methyl tertiary butyl ether (MTBE) in the single cell gel electrophoresis (Comet) assay in L-929 

mouse fibroblasts. They reported that dimethyl carbonate did not cause DNA damage in the 

assay (MTBE was positive in the assay). No other studies of genotoxicity were identified. Thus 

there is a gap in direct data on genotoxicity for dimethyl carbonate.

3.3 Human Toxicity of Dimethyl Carbonate

Dimethyl carbonate is mildly toxic by ingestion and moderately toxic by the intraperitoneal route 

(Lewis, 1996, in Sax’s Dangerous Properties of Industrial Materials: HSDB, 2009). No data 

were available in the peer-reviewed literature for chronic exposure of humans to dimethyl 

carbonate. Since so little toxicity information on dimethyl carbonate itself is available, the 

toxicity of its metabolites is summarized in the following sections.

4 Toxicity of the Metabolites of Dimethyl Carbonate (Methanol, Formaldehyde, and 

Formic Acid)

Since dimethyl carbonate breaks down to methanol and carbon dioxide, and methanol is 

metabolized to formaldehyde and formic acid, we briefly review the toxicity of the metabolites. 

In response to Health and Safety Code Section 44300 et seq., OEHHA reviewed the toxicology 

of formaldehyde and methanol and developed acute and chronic RELs for formaldehyde and 

methanol (OEHHA 1999; OEHHA, 2000; OEHHA, 2008) and an inhalation cancer unit risk 

factor for formaldehyde (OEHHA, 2009). The current health values are tabulated below (Table 

4).

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Table 4. Reference Exposure Levels and cancer inhalation unit risk values 

Chemical Acute REL Chronic REL Unit Risk (cancer)

Methanol 28,000 μg/m3 4000 μg/m3 None

Formaldehyde 55 μg/m3 9 μg/m3 6 x 10-6 (μg/m3)

-1

4.1 Toxicity of Methanol

The National Toxicology Program reviewed methanol, concentrating on its reproductive and 

developmental toxicity (NTP-CERHR, 2003). An expert panel judged that the human data were 

insufficient to evaluate the developmental toxicity of methanol but concluded, based on data 

from rodents, that developmental toxicity was the most sensitive reproductive endpoint of 

concern for humans from methanol exposure. Other general reviews of methanol toxicity 

include Roe (1955) and Kavet and Nauss (1990). 

Inhalation of methanol by humans is associated with headache and narcosis due to methanol 

itself. Ingestion of methanol induces blindness in humans (Roe 1955). Medinsky and Dorman 

(1995) reviewed the disposition of methanol and of formate, its first metabolite, in humans, nonhuman primates, and rodents after neurotoxic doses

Formate is also formed endogenously from serine and is detoxified to CO2 and H2O by a 

tetrahydrofolate (THF)-dependent pathway. Rodents detoxify formate more rapidly than 

primates. Species (e.g., rodents) with high liver THF levels are less sensitive to neurotoxicity 

due to large doses of methanol than species with low THF levels (e.g., humans and non-human 

primates). The capacity of primates to detoxify formate from low level methanol inhalation can 

be extrapolated to assess human risk from methanol. 

Cynomolgus monkeys exposed to 10-200 ppm [14C]methanol for 2 hours have blood levels of 

methanol-derived formate that are 100- to 1000-fold lower than endogenous levels of formate 

(Dorman et al., 1994). Healthy human volunteers exposed at rest or during exercise to 200 ppm 

methanol for 6 hours (Lee et al., 1992) or exposed to 20 mg/kg orally have elevated blood levels 

of methanol, but blood formate levels are not significantly increased above endogenous levels. 

Deficiencies in THF may prolong elevated blood levels of formate and increase the likelihood of 

toxicity. Monkeys with low THF levels exposed to 900 ppm [

14C]methanol for 2 hours had 

methanol-derived blood formate levels below endogenous levels (Dorman et al., 1994). 

Medinsky and Dorman (1995) suggested that humans may not be at added risk of neurotoxicity 

from low level methanol exposure by inhalation.

Since dimethyl carbonate is metabolized in the body to methanol, we reviewed a study of 

methanol by the oral route. Sprague-Dawley rats (30 animals/sex/dose) were gavaged daily with 

0, 100, 500, or 2500 mg/kg/day methanol (U.S. EPA, 1986). At six weeks, 10 rats/sex/dose 

group were subjected to interim necropsy and the other 20 were dosed until necropsy at 90 days. 

No differences between dosed and controls were found for body weight gain, food consumption, 

and gross or microscopic evaluations. There were elevated levels of serum glutamate pyruvate 

transaminase (SGPT, alanine aminotransferase), serum alkaline phosphatase (SAP), and 

increased, but not statistically significant, liver weights in both male and female rats at the 

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highest dose. These effects could be treatment-related although there were no liver lesions 

detected by histopathology. In addition, brain weights in both high-dose males and females were 

significantly less than control group. The U.S. EPA considered 500 mg/kg/day of methanol a 

NOAEL for rats (U.S. EPA, 2008). 

4.2 Toxicity of Formaldehyde

Formaldehyde gas is listed under Proposition 65 as a chemical known to the State to cause 

cancer. In 2006, the International Agency for Research on Cancer (IARC) classified 

formaldehyde as carcinogenic to humans (Group 1) (IARC, 2006). Although the listing under 

Proposition 65 relates to inhalation exposure, the IARC classified formaldehyde as carcinogenic 

to humans with sufficient evidence in humans and in experimental animals, without reference to 

route of exposure. IARC noted tumors in rat studies by the oral route: statistically significant 

increases in forestomach papillomas in one study; statistically significant increases in 

gastrointestinal leiomyosarcomas in a drinking water study (which included transplacental 

exposure); and a statistically significant increase in haemolymphoreticular tumors [lymphomas 

and leukemias] in high dose males in another drinking water study. IARC also concluded that 

"there is strong but not sufficient evidence for a causal association between leukaemia and 

occupational exposure to formaldehyde." The Agency for Toxic Substances and Disease 

Registry has produced a comprehensive review of the toxicity of formaldehyde (ATSDR, 1999). 

The non-cancer adverse health effects of airborne formaldehyde are due to its irritation of 

mucous membranes. As a result of its solubility in water and high reactivity, formaldehyde is 

efficiently absorbed into the mucus layers protecting the eyes and respiratory tract where it 

rapidly reacts, leading to localized irritation. Acute high inhalation exposure may lead to eye, 

nose and throat irritation, and in the respiratory tract, nasal obstruction, pulmonary edema and 

dyspnea. Prolonged or repeated exposures have been associated with allergic sensitization, 

asthma-like symptoms, histopathological changes in respiratory epithelium, and decrements in 

lung function. Children, especially those diagnosed with asthma, may be more likely to show 

impaired pulmonary function and symptoms of asthma than are adults following chronic 

exposure to formaldehyde. However, in the case of dimethyl carbonate exposure, formaldehyde 

would only be formed internally where it is rapidly metabolized to formate. Thus, respiratory 

tract irritation from the formaldehyde metabolite is not an issue in this case.

4.3 Toxicity of Formic Acid

Formic acid has been used in workplaces for decades and has an acceptable workplace exposure 

level (TLV) of 5 ppm (ACGIH, 2007). 

Since formic acid is one of the metabolites of methanol, staff looked for relevant toxicity studies 

on it in the open literature. Although much of the toxicity data is from inhalation exposure, in 

the present application the concern is the internal level of formic acid (or formate ion) in solution 

due to metabolism of dimethyl carbonate, not the external air concentrations of the chemicals. 

We did not find any informative studies of formate by ingestion. Nonetheless, we briefly 

describe the inhalation studies below.

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Animal Toxicity of Formic Acid

Amdur (1960) exposed guinea pigs (n=7-16/level) by inhalation to 0.34, 1.0, 2.8, 6.6, 13.5, or

42.5 ppm formic acid for 1 hour. The LOAEL was 42.5 ppm and the NOAEL was 13.5 ppm for 

overt respiratory irritation (measured by decreased breaths per minute), but more subtle adverse 

effects on lung function were measured at all the lower concentrations. 

NTP (1992) conducted 2- and 13-week toxicity studies in male and female F344/N rats and 

B6C3F1 mice exposed by whole body inhalation exposure to formic acid vapors. 

In 2-week studies, groups of 5 F344/N rats and 5 B6C3F1 mice of each sex were exposed 6 

hours/day, 5 days/week for two weeks, to 0, 31, 62.5, 125, 250, or 500 ppm. Deaths occurred in 

animals exposed to 500 ppm (rats and mice) and 250 ppm (1 female mouse).

In 13-week studies, F344/N rats and B6C3F1 mice (10 animals/group/sex) were exposed to 0, 8, 

16, 32, 64, and 128 ppm formic acid 6 hours/day, 5 days/week. One male and one female mouse 

in the 128 ppm groups died. Body weight gain was significantly decreased in mice exposed to 

64 and 128 ppm. 

In both the 2-week and 13-week studies, microscopic lesions of squamous metaplasia, necrosis, 

and inflammation in the respiratory and olfactory epithelia were detected in rats and mice. These 

were observed at 62.5 ppm and above after 2 weeks, but only at 128 ppm after 13 weeks. NTP 

concluded that the effects of formic acid were consistent with those of other irritants 

administered by inhalation. The no-observed-adverse-effect level (NOAEL) for respiratory 

injury was 32 ppm in rats and mice. There was no significant evidence of systemic toxicity. 

Formate inhibits cytochrome c oxidase activity in the electron transport chain in intact 

mitochondria and in submitochondrial particles. The inhibition increases with decreasing pH, 

indicating that HCOOH may be the inhibitory species. Formate is permeable through the inner 

mitochondrial membrane (Nicholls, 1976) and could inhibit oxidative phosphorylation.

In genetic toxicity tests in vitro with Salmonella typhimurium, formic acid was not mutagenic 

either with or without metabolic activation (NTP, 1992). 

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5 Derivation of Acute Screening Level (1-hour exposure) for Dimethyl Carbonate 

Study Bevan and Beyer, 1995; Exxon, 1992

Study population Pregnant female CD-1 mice

Exposure method Inhalation of 0, 300, 1000, or 3000 ppm 

Exposure duration 6 hours/day on gestation days 6 to 15

Critical effects Fetal malformations

NOAEL 1000 ppm

Extrapolation to 1 hour not done with developmental study (see below)

Interspecies uncertainty factor

 Toxicokinetic UFA-k 2 (default)

 Toxicodynamic UFA-d √10 (default)

Intraspecies uncertainty factor

 Toxicokinetic UFH-k 10 (default)

 Toxicodynamic UFH-d √10 (default)

Cumulative uncertainty factor 200

Acute Screening Level 5 ppm (18 mg/m3

; 18,000 μg/m3)

The acute screening level for dimethyl carbonate is based on a developmental study in which 

pregnant mice were exposed 6 hours per day for 10 days. However, the resulting acute screening 

level is a level not to be exceeded in any one hour period. The acute screening level was 

developed using methodology published in 2008 (OEHHA, 2008). The methodology was 

modified from earlier methodology (OEHHA, 1999) due to a mandate to specifically insure that 

infants and children are protected from the adverse effects of chemicals. Because of the limited 

data available on dimethyl carbonate, default values were used for the uncertainty factors (UF). 

The default interspecies UFA-k of 2 was used for residual toxicokinetic differences in studies of 

non- primate species using the human equivalent concentration (HEC) approach. In this case the 

HEC adjustment factor was 1 since fetal malformations occur internally. The default 

interspecies UFA-d of √10 was applied to compensate for the absence of data on 

pharmacodynamic differences between rodents and humans. The default intraspecies UFA-k of 

10 was used since there was no information on dimethyl carbonate metabolism at different stages 

of human development. The default interspecies UFA-d of √10 was applied to compensate for the 

absence of data on pharmacodynamic differences among humans to the effects of dimethyl 

carbonate. 

The acute screening level of 18,000 μg/m3 is somewhat more than half that for methanol (28,000 

μg/m3). 

6 Derivation of Chronic Screening Level for Dimethyl Carbonate

No data are available on long term inhalation of dimethyl carbonate. However, since one mole 

of dimethyl carbonate is degraded to two moles of methanol plus one mole of carbon dioxide, a 

chronic screening level can be based on the chronic REL for methanol as a surrogate, assuming 

100% conversion to methanol occurs during metabolism. The derivation of OEHHA’s chronic 

REL for methanol, done by an earlier methodology (OEHHA, 2000), follows:

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Methanol Chronic Reference Exposure Level

Study Rogers et al. (1993)

Study population Pregnant mice

Exposure method Inhalation of 0, 300, 1000, or 3000 ppm 

Exposure duration 7 hours/day on gestation days 6 to 15

Critical effects Abnormal cervical ribs, exencephaly, cleft palate

NOAEL 1000 ppm

Benchmark Concentration (BMC05) 305 ppm

Average experimental exposure 89 ppm at BMC05 (305 ppm x 7/24)

Human equivalent concentration 89 ppm at BMC05 (gas with systemic effects,

 based on RGDR = 1.0 using default

 assumption that lambda (a) = lambda (h))

Subchronic uncertainty factor 1

LOAEL uncertainty factor 1 

Interspecies uncertainty factor 3

Intraspecies uncertainty factor 10

Cumulative uncertainty factor 30

Chronic Methanol Reference 3 ppm (4 mg/m3

; 4,000 μg/m3)

Exposure Level

Since, as noted above, one mole of dimethyl carbonate gives rise to two moles of methanol, it is 

reasonable to extrapolate from the methanol REL of 3 ppm to an interim chronic screening level

for dimethyl carbonate of 1.5 ppm. This is equivalent to 1.5 x 3.68 x 103= 5500 μg/m3. The 

chronic REL for methanol is derived from a developmental study in which the critical exposures 

were over a relatively short timescale, rather than a long-term study. However, unlike the 

situation for dimethyl carbonate, there are several long-term studies of other endpoints in both 

rodents and primates which confirm that the developmental endpoint is the most sensitive (see 

Section 5 and the toxicity summary for the methanol chronic REL [OEHHA, 2008]). The REL 

thus derived is therefore protective against these other effects, which included liver toxicity and 

neurological or neuromuscular effects. Use of the methanol REL as an indirect basis for the 

dimethyl carbonate screening level is thus the preferred option, although alternatively it could be 

argued that a screening level based on the developmental toxicity data for dimethyl carbonate 

should be similarly protective of chronic effects. 

7 Data Gaps

Data gaps of concern to OEHHA staff include:

1. No lifetime inhalation study of dimethyl carbonate is available. The longest inhalation 

study available in the open literature is an abstract of a 10 day developmental toxicity 

study in mice (Bevan and Beyer, 1995). This is a serious data gap for a high production 

volume chemical.

2. A substantial developmental toxicity study with group sizes of 30-32 pregnant female

mice was reported, but no multigenerational studies or other investigations addressing 

reproductive toxicity in either sex were available. 

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3. There are no data in neonatal animals of the effects of dimethyl carbonate or formic acid

exposure. OEHHA has a mandate to determine if our health values adequately protect 

infants and children. 

4. There are very few data on genotoxicity of dimethyl carbonate itself. This is a source of 

concern which is partially alleviated by the fact that the first metabolite, methanol, is not 

genotoxic. The subsequent metabolites include formate, which is not genotoxic, and 

formaldehyde which is. The genotoxicity of formaldehyde when it is generated internally 

is probably only important in high dose situations, in view of its role in intermediary 

metabolism and the generally negative profile of various compounds of which it is a 

metabolite, including methanol.

8 Conclusion

There are no carcinogenicity or long-term toxicity data on dimethyl carbonate. There is no 

human evidence for carcinogenicity of methanol, the primary metabolite of dimethyl carbonate 

(along with carbon dioxide), despite a long history of human exposure. There is also a robust 

database on toxicity of methanol in animals, but only limited evidence for carcinogenicity. One 

study (Soffritti et al., 2002) found possible evidence of carcinogenicity with high oral (drinking 

water) does of methanol, although the results of this study are considered equivocal by some 

analysts. Inhalation studies in rats and mice (NEDO, 1985) were negative, and supporting 

evidence (including genotoxicity tests) is also generally negative.

Exposure to workers and the general public near facilities in California using dimethyl carbonate 

will occur if it is exempted. Dimethyl carbonate is an ester and would be expected to be less 

irritating to mucous membranes than formaldehyde or formic acid. In the present application the 

concern is the internal levels of methanol and its metabolites formaldehyde and formic acid (or 

formate ion) in solution due to metabolism of dimethyl carbonate, rather than the external air 

concentrations of the chemicals. The proposed acute screening level of 18, 000 μg/m3 and 

chronic screening level of 5500 μg/m3 are expected to be protective of anticipated adverse health 

effects, including the developmental toxicity observed in the key study (Bevan and Beyer, 1995; 

Exxon, 1992) reported for dimethyl carbonate. 

These screening levels have not undergone public and peer review. It should be noted that large 

data gaps exist for dimethyl carbonate.

9 References

ACGIH (2007). American Conference of Governmental Industrial Hygienists. TLVs® and 

BEIs®. Cincinnati: American Conference of Governmental Industrial Hygienists.

ATSDR (1999). Agency for Toxic Substances and Disease Registry. Toxicological Profile for 

Formaldehyde. PB/99/166654.

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Amdur MO (1960). The response of guinea pigs to inhalation of formaldehyde and formic acid 

alone and with a sodium chloride aerosol. Int J Air Pollut. 3: 201-20.

Bevan C and Beyer B (1995). Developmental toxicity evaluation of dimethylcarbonate by 

inhalation in CD-1 mice. International Toxicologist, 7(1): AB# 74-P-2. 

Dorman DC, Moss OR, Farris GM, Janszen D, Bond JA, Medinsky MA (1994). 

Pharmacokinetics of inhaled [14C]methanol and methanol-derived [14C]formate in normal and 

folate-deficient cynomolgus monkeys. Toxicol Appl Pharmacol. 128(2): 229-38.

European Commission (2000). Dimethyl carbonate. IUCLID Dataset. European Chemicals 

Bureau. Available online at: http://ecb.jrc.ec.europa.eu/iuclid-datasheet/616386.pdf

Exxon Biomedical Sciences (1992). Inhalation development toxicity study in mice with 

dimethylcarbonate. Final report. Project number 107334. E. Millstone, NJ.

HSDB (2009). Hazardous Substances Data Bank. Available online at: 

http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB Last accessed March 4, 2009. 

IARC (2006). Formaldehyde, 2-Butoxyethanol and 1-tert-Butoxypropan-2-ol. IARC 

Monographs. Vol. 88. Lyon: International Agency for Research on Cancer.

Kavet R and Nauss KM (1990). The toxicity of inhaled methanol vapors. Crit Rev Toxicol.

21(1): 21-50.

Kowa American (2009). Dimethyl carbonate information request. Submitted by Mark K. Smith.

Lee EW, Terzo TS, D'Arcy JB, Gross KB, Schreck RM (1992). Lack of blood formate 

accumulation in humans following exposure to methanol vapor at the current permissible 

exposure limit of 200 ppm. Am Ind Hyg Assoc J. 53(2):99-104.

Lewis RJ (1996). Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New 

York, NY: Van Nostrand Reinhold, p. 2205.

Medinsky MA, Dorman DC (1995). Recent developments in methanol toxicity. Toxicol Lett. 82-

83:707-11.

Meylan WM, Howard PH (1995). Atom/fragment contribution method for estimating octanolwater partition coefficients. J Pharm Sci. 84(1):83-92.

NEDO. (1985). 24-month inhalation carcinogenicity studies on methanol in Fischer rats (test no.: 

5A-268), 10 and 18-month inhalation carcinogenicity study of methanol in B6C3F1 mice (test 

no.: 4A-223). Mitsubishi Kasei Institute for Toxicological and Environmental Sciences, 

Tokyo. Summarized in: Cruzan G (2009). Assessment of the cancer potential of methanol. 

Critical Reviews in Toxicology 39(4): 347–363

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NTP (1992). National Toxicology Program. Toxicity Studies of Formic Acid (CAS No. 64-18-6) 

Administered by Inhalation to F344/N Rats and B6C3F1 Mice. Tox-19. NIH Publication 92-

3342.

NTP-CERHR (2003). National Toxicology Program. Center for the Evaluation of Risks to 

Human Reproduction. Monograph on the Potential Human Reproductive and Developmental 

Effects of Methanol. NIH Publication No. 03-4478.

Nicholls P (1976). The effect of formate on cytochrome aa3 and on electron transport in the 

intact respiratory chain. Biochim Biophys Acta. 9;430(1):13-29

OEHHA. (1999). Air Toxics Hot Spots Program Risk Assessment Guidelines Part I. The 

Determination of Acute Reference Exposure Levels for Airborne Toxicants. Office of 

Environmental Health Hazard Assessment, California Environmental Protection Agency. 

OEHHA. (2000). Air Toxics Hot Spots Program Risk Assessment Guidelines Part III Technical 

Support Document for the Determination of Noncancer Chronic Reference Exposure Levels. 

Office of Environmental Health Hazard Assessment, California Environmental Protection 

Agency. 

OEHHA. (2008). Air Toxics Hot Spots Risk Assessment Guidelines. Technical Support 

Document for the Derivation of Noncancer Reference Exposure Levels. Air Toxicology and 

Epidemiology Branch, Office of Environmental Health Hazard Assessment, California 

Environmental Protection Agency. Available on-line at

http://www.oehha.ca.gov/air/hot_spots/rels_dec2008.html

OEHHA (2009). Office of Environmental Health Hazard Assessment. Air Toxics Hot Spots Risk 

Assessment Guidelines. Technical Support Document for Cancer Potencies. Available online at http://www.oehha.ca.gov/air/hot_spots/tsd052909.html

Röe O (1955). The metabolism and toxicity of methanol. Pharmacol Rev. 7(3):399-412.

Rogers JM, Mole ML, Chernoff N, Barbee BD, Turner CI, Logsdon TR, and Kavlock JV (1993). 

The developmental toxicity of inhaled methanol in the CD-1 mouse, with quantitative doseresponse modeling for estimation of benchmark doses. Teratology 47:175-188.

Soffritti M, Belpoggi F, Cevolani D, Guarino M, Padovani M, Maltoni C. (2002). Results of 

long-term experimental studies on the carcinogenicity of methyl alcohol and ethyl alcohol in 

rats. Ann N Y Acad Sci 982:46–69.

Song C, Zhang Z, Chen X, Zhang Y, Wang C, Liu K (2002). [Study on three kinds of gasoline 

oxygenates-induced DNA damage in mice fibroblasts] [Chinese] Zhonghua Lao Dong Wei 

Sheng Zhi Ye Bing Za Zhi. 20(5):362-4. 

SRC (2009). Syracuse Research Corporation on-line database. Accessed at 

http://www.syrres.com/what-we-do/databaseforms.aspx?id=386

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U.S. EPA (1986). Rat oral subchronic toxicity study with methanol. Office of Solid Waste, 

Washington, DC.

U.S. EPA (2008). Methanol. Integrated Risk Information System. Available online at: 

http://www.epa.gov/iris/subst/0305.htm

U.S. EPA (2009). Air Quality: Revision to Definition of Volatile Organic Compounds -

Exclusion of Propylene Carbonate and Dimethyl Carbonate. Federal Register 74(12):3437-41.

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Appendix D: SJVAPCD Risk Analysis for DMC, MF, and TBAc February 21, 2013

D-1 Final Staff Report with Appendices

For Proposed Amendments to Rule 1020

APPENDIX D

Analysis of Potential Risks from Use of Dimethyl Carbonate (DMC), 

Methyl Formate (MF), and Tertiary-Butyl Acetate (TBAc)

February 21, 2013
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San Joaquin Valley

Unified Air Pollution Control District

Date: October 24, 2012

To: Lisa Van de Water, Air Quality Specialist

From: Glenn Reed, Senior Air Quality Specialist

Subject: Analysis of Potential Risks from Use of Dimethyl Carbonate (DMC), 

Methyl Formate (MF), and tert-Butyl Acetate (tBAC)

The U.S. Environmental Protection Agency (EPA) has exempted DMC, MF, and tBAC from the 

definition of “volatile organic compounds” or “VOCs”. The San Joaquin Valley Unified Air 

Pollution Control District (the “District”) conditionally exempted tBAC and MF previously. The 

District’s Strategies and Incentives Department (SI) asked the Permit Services Department 

(PSD) to perform an analysis to determine the potential risks from exempting DMC.

On February 14, 2011, PSD personnel reported the results of the initial risk analysis. That 

analysis was based on a recent Risk Management Review for a surface coating operation. That 

analysis assumed that the coating operation occurred in a spray booth. Two scenarios were 

assumed for the booth’s stack. First, the stack was modeled with a vertical release. Second, it 

was assumed that there is a cap on the stack.

During the course of reviewing that analysis, an issue arose concerning operations that are not 

permitted. In accordance with Rule 2020, surface coating operations that use less than 1 quart 

of surface coating per day or less than 8 gallons per year are exempt from permitting. To 

analyze the risk from unpermitted sources, the following assumptions were made:

• No spray booth would be used. Emissions were modeled as a volume source.

• Receptors would be located at a minimum distance of 25 m from the volume source.

• For acute risk, the entire 1 quart per day would be used within an hour and all the 

solvent would evaporate within that hour.

• The only constituent of the coating would be the compound of interest.

• Two types of coating were analyzed: 1) a high solids coating with a solvent content of 47 

percent by volume and 2) a water-based coating with a solvent content of 5 percent by 

volume. These two coatings were selected from the information in the Air Resource 

Board’s Draft Report on the 2005 Architectural Coatings Survey. These data are for 

nonflat – high gloss coatings.

• All solvent in these two coating options were assumed to be replaced with DMC, TBAC, 

or MF.
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The following table summarizes the results:

Risk Estimates

Acute Risk for 1 Quart in 1 Hour

47 Percent VOC

Solvent-Based Coating

5 Percent VOC

Water-Based Coating

Dimethyl Carbonate 0.52 0.06

Methyl Formate 0.67 0.07

tert-Butyl Acetate 0.39 0.04

At an annual usage rate of 8 gallons per year, the maximum chronic hazard index for DMC 

would be 0.0002 and the cancer risk for tBAC would be 0.3 in a million.

Permit Services concludes from this analysis that an unpermitted source using any of these 

three compounds in reasonably anticipated ways would not pose an unacceptable risk.

Further, if usage rates of coatings containing these compounds exceed the limits in Rule 2020, 

a permit would be required. The District performs Risk Management Reviews for all operations 

that require a permit and would therefore regulate individual project risk as a part of the 

permitting process.

Attachments:

A. Basic Coating Data

B. Table of Results—Solvent-Based Coating

C. Table of Results—Water-Based Coating
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Attachment A Basic Coating Data

Specific Gravities Hourly Annual Hourly Annual

Component SB WB Dimethyl Carbonate 1.069 0.131951 0.005498 0.014037 0.000585

Solids 53 35 Methyl Formate 0.866 0.106894 0.004454 0.011372 0.000474

Water 0 60 tert-Butyl Acetate 0.98 0.120966 0.00504 0.012869 0.000536

Exempt 0 0

VOCs 47 5

Non-Flat: High Gloss

All data are taken from Table 8-1of the 2005 Architectural Coatings Survey, (Draft Report), California Air Resources 

Board, September 2006.

Basic Coating Data

Solvent-Based Water-Based

Emissions (g/sec)

Average Composition of 

Solvent-Based (SB) and 

Water-Based Architectural 

(Percent by Volume)
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Attachment B Table of Results—Solvent-Based Coating

1-Hour Annual 1-Hour Annual

Max concentration at 1 g/s 29772 1192 Max concentration at 1 g/s 71048 1492

Specific Gravities Specific Gravities

Dimethyl Carbonate 1.069 Dimethyl Carbonate 1.069

Methyl Formate 0.866 Methyl Formate 0.866

tert-Butyl Acetate 0.98 tert-Butyl Acetate 0.98

Emission Rates (g/s) Emission Rates (g/s)

Dimethyl Carbonate 0.131951 0.005498 Dimethyl Carbonate 0.131951 0.005498

Methyl Formate 0.106894 0.004454 Methyl Formate 0.106894 0.004454

tert-Butyl Acetate 0.120966 0.00504 tert-Butyl Acetate 0.120966 0.00504

Max concentration at 1 qt/day Max concentration at 1 qt/day

Dimethyl Carbonate 3928.456 6.553585 Dimethyl Carbonate 9374.881 8.202977

Methyl Formate 3182.454 5.309078 Methyl Formate 7594.619 6.645256

tert-Butyl Acetate 3601.391 6.007964 tert-Butyl Acetate 8594.372 7.520035

Risk Values Acute Chronic Cancer Risk Values Acute Chronic Cancer

Dimethyl Carbonate 18000 4000 Dimethyl Carbonate 18000 4000

Methyl Formate 11400 Methyl Formate 11400

tert-Butyl Acetate 22000 4.00E-07 tert-Butyl Acetate 22000 4.00E-07

Risk Estimates Acute Chronic Cancer Risk Estimates Acute Chronic Cancer

Dimethyl Carbonate 0.218248 0.001638 Dimethyl Carbonate 0.520827 0.002051

Methyl Formate 0.279163 Methyl Formate 0.666195

tert-Butyl Acetate 0.1637 2.40E-06 tert-Butyl Acetate 0.390653 3.01E-06

1-Hour Annual 1-Hour Annual

Max concentration at 1 g/s 3875 63 Max concentration at 1 g/s 7618 351

Specific Gravities Specific Gravities

Dimethyl Carbonate 1.069 Dimethyl Carbonate 1.069

Methyl Formate 0.866 Methyl Formate 0.866

tert-Butyl Acetate 0.98 tert-Butyl Acetate 0.98

Emission Rates (g/s) Emission Rates (g/s)

Dimethyl Carbonate 0.131951 0.005498 Dimethyl Carbonate 0.131951 0.005498

Methyl Formate 0.106894 0.004454 Methyl Formate 0.106894 0.004454

tert-Butyl Acetate 0.120966 0.00504 tert-Butyl Acetate 0.120966 0.00504

Max concentration at 1 qt/day Max concentration at 1 qt/day

Dimethyl Carbonate 511.3401 0.34408 Dimethyl Carbonate 1005.153 1.932323

Methyl Formate 414.2381 0.27874 Methyl Formate 814.277 1.565381

tert-Butyl Acetate 468.7683 0.315433 tert-Butyl Acetate 921.4682 1.771447

Risk Values Acute Chronic Cancer Risk Values Acute Chronic Cancer

Dimethyl Carbonate 18000 4000 Dimethyl Carbonate 18000 4000

Methyl Formate 11400 Methyl Formate 11400

tert-Butyl Acetate 22000 4.00E-07 tert-Butyl Acetate 22000 4.00E-07

Risk Estimates Acute Chronic Cancer Risk Estimates Acute Chronic Cancer

Dimethyl Carbonate 0.028408 8.6E-05 Dimethyl Carbonate 0.055842 0.000483

Methyl Formate 0.036337 Methyl Formate 0.071428

tert-Butyl Acetate 0.021308 1.26E-07 tert-Butyl Acetate 0.041885 7.09E-07

Urban Dispersion Coefficients Rural Dispersion Coefficients

Spray Booth with Uncapped Stack Spray Booth with Capped Stack

Substitution of VOCs in Solvent-Based Coating
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Attachment C Table of Results—Water-Based Coating

1-Hour Annual 1-Hour Annual

Max concentration at 1 g/s 29772 1192 Max concentration at 1 g/s 71048 1492

Specific Gravities Specific Gravities

Dimethyl Carbonate 1.069 Dimethyl Carbonate 1.069

Methyl Formate 0.866 Methyl Formate 0.866

tert-Butyl Acetate 0.98 tert-Butyl Acetate 0.98

Emission Rates (g/s) Emission Rates (g/s)

Dimethyl Carbonate 0.014037 0.000585 Dimethyl Carbonate 0.014037 0.000585

Methyl Formate 0.011372 0.000474 Methyl Formate 0.011372 0.000474

tert-Butyl Acetate 0.012869 0.000536 tert-Butyl Acetate 0.012869 0.000536

Max concentration at 1 qt/day Max concentration at 1 qt/day

Dimethyl Carbonate 417.9209 0.69719 Dimethyl Carbonate 997.3278 0.872657

Methyl Formate 338.5589 0.564796 Methyl Formate 807.9382 0.706942

tert-Butyl Acetate 383.1267 0.639145 tert-Butyl Acetate 914.2949 0.800004

Risk Values Acute Chronic Cancer Risk Values Acute Chronic Cancer

Dimethyl Carbonate 18000 4000 Dimethyl Carbonate 18000 4000

Methyl Formate 11400 Methyl Formate 11400

tert-Butyl Acetate 22000 4.00E-07 tert-Butyl Acetate 22000 4.00E-07

Risk Estimates Acute Chronic Cancer Risk Estimates Acute Chronic Cancer

Dimethyl Carbonate 0.023218 0.000174 Dimethyl Carbonate 0.055407 0.000218

Methyl Formate 0.029698 Methyl Formate 0.070872

tert-Butyl Acetate 0.017415 2.56E-07 tert-Butyl Acetate 0.041559 3.20E-07

1-Hour Annual 1-Hour Annual

Max concentration at 1 g/s 3875 63 Max concentration at 1 g/s 7618 351

Specific Gravities Specific Gravities

Dimethyl Carbonate 1.069 Dimethyl Carbonate 1.069

Methyl Formate 0.866 Methyl Formate 0.866

tert-Butyl Acetate 0.98 tert-Butyl Acetate 0.98

Emission Rates (g/s) Emission Rates (g/s)

Dimethyl Carbonate 0.014037 0.000585 Dimethyl Carbonate 0.014037 0.000585

Methyl Formate 0.011372 0.000474 Methyl Formate 0.011372 0.000474

tert-Butyl Acetate 0.012869 0.000536 tert-Butyl Acetate 0.012869 0.000536

Max concentration at 1 qt/day Max concentration at 1 qt/day

Dimethyl Carbonate 54.39788 0.036604 Dimethyl Carbonate 106.9311 0.205566

Methyl Formate 44.06788 0.029653 Methyl Formate 86.62521 0.16653

tert-Butyl Acetate 49.86897 0.033557 tert-Butyl Acetate 98.02853 0.188452

Risk Values Acute Chronic Cancer Risk Values Acute Chronic Cancer

Dimethyl Carbonate 18000 4000 Dimethyl Carbonate 18000 4000

Methyl Formate 11400 Methyl Formate 11400

tert-Butyl Acetate 22000 4.00E-07 tert-Butyl Acetate 22000 4.00E-07

Risk Estimates Acute Chronic Cancer Risk Estimates Acute Chronic Cancer

Dimethyl Carbonate 0.003022 9.15E-06 Dimethyl Carbonate 0.005941 5.14E-05

Methyl Formate 0.003866 Methyl Formate 0.007599

tert-Butyl Acetate 0.002267 1.34E-08 tert-Butyl Acetate 0.004456 7.54E-08

Urban Dispersion Coefficients Rural Dispersion Coefficients

Spray Booth with Uncapped Stack Spray Booth with Capped Stack

Substitution of VOCs in Water-Based Coating
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