SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

1 **Final Staff Report w**  **ith Appendices**

**for Proposed Amendments to Rule 1020**  SAN JOAQUIN VALLEY U NIFIED AIR POLLUTION CONTROL DISTRICT

FINAL STAFF REPORT

Proposed Amendments to Rule 1020 ( Definitions )

February 21 , 201 3

Prepared by: Lisa Van de Water, Air Quality Specialist

Review ed 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 th ey 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 a nd PC have a low potential to form ozone in the atmosphere . EPA found that the se compounds are less photo

- chemically reactive than ethane and, thus, ha ve a negligible
contribution to ozone formation . EPA announced the exemption of DMC and PC in the
Feder al 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.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

2 **Final Staff Report w**  **ith Appendices**

**for Proposed Amendments to Rule 1020**  The District als o 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 ana lysis 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 comp ounds 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) res idents

.

II. RULE DEVELOPMENT PROCESS

As par t 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

. T he District postponed further action on the proposed amendments to Rule 1020 based on a request by ARB to allow them a n opportunity to further review the issue on a statewide basis. ARB ultim ately 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 ma d e available the proposed amendments to Rule 1020 to
stakeh olders for review prior to a public hearing of the Governing Board to consider adoption of the proposed rule amendments

. The District evaluate d comments received and incorporate d them as appropriate

. The p roposed 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 VOC s several times to exclude organic compounds
from the definition of VOC s 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 a re 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

- chemicallySAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

3 **Final Staff Report w**  **ith Appendices**

**for Proposed Amendments to Rule 1020**  reactive than ethane and, thus, have negligible c ontribution 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 atmo sphere 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 y ear 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
threshol d 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 S ection 3.53
in the rule

. In July 2004

, Kowa petitioned the federal government to exemp t DMC as a
VOC

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

B ) after several years of evaluation of the ozone

- reducing values and environmental, toxicity, and safety profiles of these compounds

.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

4 **Final Staff Report w**  **ith Appendices**

**for Proposed Amendments to Rule 1020**  Section 3.53 of Rule 1020 defines VOC s 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 amendment s to Rule 1020 change s the definition of VOC i n 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 compound s 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

. F or 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 oper ations

.

T he 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 a cetone, 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 t oxic a ir c ontaminants by the ARB

. Base d 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

- reg ulated 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 b e 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 Assessmen t (OEHHA) conducted an assessment of the health effects of exposure to DMC

. No data is available in the peer

reviewed literature for chronic exposure of humans to DMC

. However, one teratologySAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

5 **Final Staff Report w**  **ith Appendices**

**for Proposed Amendments to Rule 1020**  study conducted by Exxon in 1992 indicates maternal a nd developmental toxicity on
mice when exposed to high (3,000 ppmv ) inhalation exposure level s

. 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 sc reening
value of 18,000 mg/m 3 and chronic screening value of 5

, 500 mg/m 3 are expected to be protective of anticipated adverse health effects, including the developmental toxicity observed in the Exxon study noted above

. T he 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, c hronic, 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 Di strict’s Risk

- b ased Strategy, t he 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 Per mitting 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

e ffect that such compounds have when combined with other compounds with potential
risk

. Given the thorou gh 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 leve l s ) , will be assessed and mitigated during the perm itting 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 req uire permitting because of the amount of productSAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

6 **Final Staff Report w**  **ith Appendices**

**for Proposed Amendments to Rule 1020**  used, a nd therefor e 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 coating s used for commercial or residential applications.” Such coatings are regulated by ARB as consumer products and are not normal ly
considered by the District

. Similarly, worker exposure issues are the purview of the
California OSHA

. Surface coating operations, wh ich 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

. Ther efore, 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 selec ted coatings ( contain ing 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 water

based coating with 5% VOC content

. Initially, s taff 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 s tack

. For all VOCs evaluated, the rural dispersion from a volume source using the solvent

- based coating resulted in the highest acute, chro nic, and cancer risk estimates given the exemption limits in Rule 2020

— one quart per day for acute risk ( assuming th at 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 riskSAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

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**for Proposed Amendments to Rule 1020**  managemen t 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 t o 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 the se 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 als o 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 application s 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 C lean 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. B ecause this compo und 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 p hysical and chemical properties of the compounds DMC and
PC might replace

.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

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**f or Proposed Amendments to Rule 1020**  Table 2

– Comparison of Currently

- Used Solvents, Dimethyl Carbonate and Propylene Carbonate

Property Acetone Ethylene Glycol Isoprop yl
Alcohol Methyl Acetate Methyl Ethyl
Ketone 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 C 3 H 6 O HOCH 2 CH 2 OH (CH 3 ) 2 CHOH CH 3 COOCH 3 CH 3 COCH 2 CH 3 (CH 3 ) 2 CO 3 C 4 H 6 O 3

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 0.0 2 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

NFPA A 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 LevelSAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

9 **Final Staff Report w**  **ith Appendices**

**f or Proposed Amendments to Rule 1020**  Table 2 (continued)

– Compar ison of Currently

- Used Solvents to Dimethyl Carbonate and Propylene Carbonate

Property Acetone Ethylene Glycol Isopropyl
Alcohol Methyl Acetate Methyl Ethyl
Ketone Dimethyl
Carbonate Propylene
Carbonate

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

Acute Inhalation

RE L None None 3,2 00 ug/m 3 None 18,000 ug/m 3 1 8,000 ug/m 3 B ,C None

Chronic Inhalation

RE L No ne 400 ug/m 3 7,000 ug/m 3 No ne No ne 5 ,000 ug/m 3 B ,C No ne

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 LevelSAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

10 **Final Staff Report w**  **ith Appendices**

**f or Proposed Amendments to Rule 1020**  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, A RB and the Legislature will be developing policies and programs to implement
AB 32

. The District believes th at 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 pu blic 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 (C EQA) 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 compound s

, and emissions reductions would be expected from any VOC

containing solvents ultimately replaced by these newly exempted com pounds. 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

S ince 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
socio economic impacts when adopting, amending, or repealing a rule that significantlySAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

11 **Final Staff Report w**  **ith Appendices**

**f or Proposed Amendments to Rule 1020**  affects air quality or emissions limitations. A socioeconomic impact analysis is not required for this rule amendment because the proposed amendments do not establish
emissio n 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 com pou nds
list contained in District Rule 1020 (Definitions). As pres ented in the Final Staff Report, EPA considers these chemicals to be exempt volatile organic compounds; these chemicals are already in use in California i n cosmetics and other products; and

, while manufacturers and other businesses may choose to reformulate existing products, the
Rule 1020 amendments est ablish no requirement to do so.

T here is no substantial evidence in the w hole record before the District that the

p roposed amendments to Rule 1020 would cause any adve rse 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 envi ronment ( 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 corr esponding 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 recordke eping 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: Rev ision to Definition of Volatile Organic Compounds

-- Exclusion of Propylene Carbonate and Dimethyl Carbonate , 74 Fed. Reg . 12, pp

. 3437

– 3441. (200 9 , 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

.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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12 **Final Staff Report w**  **ith Appendices**

**f or Proposed Amendments to Rule 1020**  This page intentionally blank.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Comments and Responses February 21 , 201 3

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### APPENDIX A

SUMMARY OF SIGNIFICANT COMMENTS AND RESPONSES FOR
PROPOSED AMENDMENTS TO RULE 1020

February 21 , 201 3SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Comments and Responses February 21 , 201 3

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Appendix A: Comments and Responses February 21 , 201 3

A

- 3 **Final Staff Report with Appendices For Proposed Amendments to Rule 1020**  SUMMARY OF SIGNIFICANT COMMENTS AND RESPONSES TO
PROPOSED AMENDMENTS TO RUL E 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.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Comments and Responses February 21 , 201 3

A

- 4 **Final Staff Report with Appendices For Proposed Amendments to Rule 1020**  SUMMARY OF SIGNIFICANT COMMENTS AND RE SPONSES 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 comment s.

California Air Resources Board (ARB) Comments

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

t o estimate likely indoor exposures to DMC during realistic but high

- exposure conditions

. Since DMC may be used in paints and solv ents, we are estimating exposures from painting a small, residential bathroom as well at auto repair shops. ARB expect s to complete the assessment and send an advisory memo
on DMC to California Air Pollution Control Officers Association (CAPCOA) next

mont h (January 2011)

. T he rule project should be delayed until the advisory

memo i s 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 propose d 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 subm itting comments:

American Coatings Association (ACA) Kowa American Corporation (KAC) Lyondell Basell 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 andSAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Comments and Responses February 21 , 201 3

A

- 5 **Final Staff Report with Appendices For Proposed Amendments to Rule 1020**  

### 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 V OC exempt solvents is a form of regulatory relief that your constituents will welcome

. (KAC)

RESPONSE: A dditional technical information about this chemical originally provided with this comment has been evaluated and incorporated into the Final
Staff Re port as appropriate

.

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

- to

- Operate ( PTO ) requireme nts as methyl formate since the two
chemicals share the common metabolite methanol. (LBI)

RESPONSE: The proposed amend ments 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 TBA c 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 , 201 3

A

- 6 **Final Staff Report with Appendices For Proposed Amendments to Rule 1020**  This page intentionally blank.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix B: Federal Register Announcement February 21 , 20 13

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 , 20 13SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix B: Federal Register Announcement February 21

, 20 13

B

- 2 **Final Staff Report with Appendices** 

**For Proposed Amendments to Rule 1020**  This page intentionally blank.3437 Federal Register / Vol. 74, No. 12 / Wednesday, January 21, 2009 / Rules and Regulations

**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 (NO X ) react in the atmosphere. Because of the harmful health effects of ozone, EPA and state governments limit the amount of VOCs
and NO X 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
k OH ), (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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1 Basil 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. T ABLE 1—R EACTIVITIES OF E THANE AND C OMPOUNDS C ONSIDERED FOR E XEMPTION

Compound k OH (cm 3 /molecule-sec) MIR (g O 3 /mole VOC) MIR (g O 3 /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. k OH 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. k OH 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. k OH 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 O 3 /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 O 3 /mole VOC) values were calculated from the MIR (g O 3 /g VOC) values by determining the number of moles per gram of the relevant organic compound.

The k OH 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 k OH 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 k OH 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 k OH 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 k OH 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 registrynumber 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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2 The 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 k OH 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 O 3 /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 O 3 /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 O 3 /mole VOC) value. None of the comments received during the public comment period opposed using the g O 3 /g VOC basis. In fact, the
comments which addressed that issue supported the use of the MIR on a g O 3 / 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
k OH and MIR values for the compound. These articles have been placed in the
docket.

As shown in Table 1, DMC has a greater k OH 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 k OH 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 , 20 13SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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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 methylati o n re a c t ions (HSDB, 2009) , and has possible uses in paints, coat i ngs, 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 co ntains 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 di methyl carbon ate.

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 regu lation, and its use becomes more widespread in California. Th ere 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 a cute and chronic screening values for dimethyl carbonate to compare to estimated exposures from use in California. Additionally, we discuss formation and toxicity of possible

d imethyl carbonate metabolites

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2 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 @ 25 o C/15 o C Boiling point 90

- 91 oC 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 Mi scible with alcohol and ether;

I nsoluble in water (HSDB, 2009);

Solubi lity = 13.9 g/100 g water (Kowa American, 2009) Flammability Highly flammable Conversion factor 3.68 μg/m 3 per ppb @ 25oC

3 Toxicity of Dimethyl Carbonate

3.1 Metabolism of Dimethyl Carbonate

Dimethyl carbonate is readily hydrolyzed to carbon dioxide and m ethanol in the environment and presumably in the body via esterases (Kowa America, 2009) . Methanol is metaboli zed 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 tox icity, and toxicity to terrestrial organisms.

The IUCLID dataset lists a rat 4 hour LC 50 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 rab bit 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 gestationa l days ( gd ) 6 through 15 for 6 h/day

. The females were

euthaniz ed 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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3 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

- s tunted 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 f used vertebral

arches

. S keletal 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 ( NO A EL ) for maternal and de velopmental 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). San Joaquin Valley Unified Air Pollution Control District

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4 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 s ingle cell gel electrophoresis (Comet) assay in L

- 929

mouse fibr oblasts

. They reported that dimethyl carbonate did not cause DNA damage in t he

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 Tox icity 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 lit erature 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, 200 9 ). The current health values are tabulated below (Table 4)

. San Joaquin Valley Unified Air Pollution Control District

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5 Table 4. Reference Exposure L evels and cancer inhalation unit risk values

Chemical Acute REL Chronic REL Unit Risk (cancer)

Methanol 28,000 μg/m 3 4000 μg/m 3 None Formaldehyde 55 μg/m 3 9 μg/m 3 6 x 10 - 6 (μg/m 3 ) - 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 hu man 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 r eviews 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 D orman (1995) reviewed the disposition of methanol and of formate, its first metabolite

, in humans, non

human primates, and rodents after neurotoxic doses

Formate is also formed endogenously from serine and is detoxified to CO 2 and H 2 O 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

- hu man 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 [ 14 C]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 likeli hood of toxicity. Monkeys with low THF levels exposed to 900 ppm [ 14 C] 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 review e d 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, fo od 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 i n both male and female rats at the San Joaquin Valley Unified Air Pollution Control District

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6 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 ev idence 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

ga strointestinal 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 a lso 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 dy spnea. 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 metabo lized 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 meth anol , 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 th e internal level of formic acid (or formate ion) in solution

due to metabolism of di methyl carbon ate, 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. San Joaquin Valley Unified Air Pollution Control District

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7 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. Th e 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

B6C3F 1 mice exposed by whole body inhalation exposure to formic acid vapors.

In 2

- week studies, groups of 5 F344/N rats and 5 B6C3F 1 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 t o 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 w as significantly decreased in mice exposed to 64 and 128 ppm.

In both the 2

- week and 13

- week studies, micro scopic 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 t he 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.

F ormate 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). San Joaquin Valley Unified Air Pollution Control District

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8 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, 100 0

, 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 UF A

- k 2 (default) Toxicodynamic UF A

- d √10 (default)

Intr aspecies uncertainty factor

Toxicokinetic UF H

- k 10 (default) Toxicodynamic UF H

- d √10 (default) Cumulative uncertainty factor 2 00

Acute Screening Level 5 ppm ( 18 mg/m 3 ; 1 8 ,000 μ g/m 3 )

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 de veloped 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 UF A

- k of 2 was used for residual toxicokinetic differences in studies of

non

- primate species using the human equival ent concentration ( HEC ) approach. In this case the

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

- d of √10 was applied to compensate for the absence of data on
pharmacodynamic differences between rodents and humans . The default intraspecies UF A

- k of 10 was used since there was no information on dimethyl carbonate metabolism at different stages of human development. The default interspecies UF A

- 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 1 8

, 0 00 μ g/m 3 is so mewhat more than half that for methanol (28,000 μg/m 3 ).

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 meth anol 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: San Joaquin Valley Unified Air Pollution Control District

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9 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 Concentrati on (BMC 05 ) 305 ppm Average experimental exposure 89 ppm at BMC 05 (305 ppm x 7/24) Human equivalent concentration 89 ppm at BMC 05 (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/m 3 ; 4 ,000 μ g/m 3 ) Exposure Level

Since, as noted above, one mole o f 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 10 3 = 5500 μ g/m 3

. The

chr onic 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 the se 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 s tudy 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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10 3. There are no data i n neonatal animals of the effects of dimethyl car bonate 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 alleviate d 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 importan t in high dose situations, in view of its role in intermediary metabolism and the generally negative profile of various compound s of which it is a metabolite, including methanol.

8 Conclusion

There are no carcinogenicity or long

- term toxicity data on dimethy l 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 animal s , 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, 198 5 ) 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 f ormaldehyde and formic acid (or formate ion) in solution due to metabolism of di methyl carbon ate, rather than the external air

concentrations of the chemicals. The proposed acute screening level of 18, 000 μ g/m 3 and

chronic screening level of 5500 μ g/m 3 a re 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 p eer 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. San Joaquin Valley Unified Air Pollution Control District

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

alone an d with a sodium chloride aerosol. Int J Air Pollut. 3: 201

- 20.

Bevan C and Beyer B ( 1995 ) . Developmental t oxicity e valuation of d imethylcarbonate by

i nhalation in CD

- 1 m ice. International Toxicologist, 7(1): AB# 74

- P

- 2.

Dorman DC, Moss OR, Farris GM, Janszen D, Bond JA, Medinsky MA (1994). Pharmacokinetics of inhaled [ 14 C]methanol and methanol

- derived [ 14 C]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 107 334. 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). For maldehyde, 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

exp osure 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 octanol

water partition coefficients. J Pharm Sci. 84(1):83

- 92.

NEDO. (1985). 24

- month inhalation carcinogenicity stud ies on methanol in F i scher 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 San Joaquin Valley Unified Air Pollution Control District

C-14 Appendix C: OEHHA Screening Values for DMC February 21, 2013

Final Staff Report with Appendices For Proposed Amendments to Rule 1020Dimethyl Carb onate

– screening values 2/ 16 / 2012

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

- 18

- 6) Administered by Inhalation to F344/N Rats and B6C3F 1 Mice. Tox

- 19. NIH Publication 9 2

- 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 (2 009 ). Office of Environmental Health Hazard Assessment. Air Toxics Hot Spots Risk

Assessment Guidelines. Technical Support Document for Cancer Potencies . Available on

line 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 dose

response 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 Corporati on on

- line database. Accessed at http://www.syrres.com/what

- we

- do/databaseforms.aspx?id=386 San Joaquin Valley Unified Air Pollution Control District

C-15 Appendix C: OEHHA Screening Values for DMC February 21, 2013

Final Staff Report with Appendices For Proposed Amendments to Rule 1020Dimethyl Carb onate

– screening values 2/ 16 / 2012

13 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 S ystem. 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. San Joaquin Valley Unified Air Pollution Control District

C-16 Appendix C: OEHHA Screening Values for DMC February 21, 2013

Final Staff Report with Appendices For Proposed Amendments to Rule 1020SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

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- 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 T ert iary

- Butyl Acetate ( TBAc )

February 21 , 20 13SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

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- 3 **Final Staff Report with Appendices For Proposed Amendments to Rule 1020**  

## 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 d etermine 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 fro m 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

– hig h gloss coatings.

• All solvent in these two coating options were assumed to be replaced with DMC, TBAC,
or MF.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

D

- 4 **Final Staff Report with Appendices For Proposed Amendments to Rule 1020**  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 thes e 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.

Attac hments:
A. Basic Coating Data

B. Table of Results

— Solvent

- Based Coating
C. Table of Results

— Water

- Based CoatingSAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

D

- 5 **Final Staff Report with Appendices For Proposed Amendments to Rule 1020**  **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)SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

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- 7 **Final Staff Report with Appendices For Proposed Amendments to Rule 1020**  **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 CoatingSAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

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- 9 **Final Staff Report with Appendices For Proposed Amendments to Rule 1020**  **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 CoatingSAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

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

D

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