SACRAMENTO METROPOLITAN 

AIR QUALITY MANAGEMENT DISTRICT

STAFF REPORT 

Proposed Amendments To 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Prepared by: David Yang 

Associate Air Quality Engineer

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

 Program Coordinator 

 Aleta Kennard 

Program Supervisor

Approved by: Brigette Tollstrup 

Division Manager 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 1 

EXECUTIVE SUMMARY 

Since Rule 101, General Provisions and Definitions, was last amended on September 3, 1998, 

the United States Environmental Protection Agency (EPA) has revised the federal definition of 

volatile organic compound (VOC) in Title 40, Part 51 of the Code of Federal Regulations several 

times to include additional compounds that negligibly contribute to the formation of ozone. The 

following eight compounds were added to the list: 

 1,1,1,2,2,3,3-heptafluoro-3-methoxy-propane (n-C3F7OCH3 or HFE-7000) 

 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-(trifluoromethyl) hexane (HFE-7500) 

 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) 

 methyl formate (HCOOCH3) 

 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-trifluoromethyl-pentane (HFE-7300) 

 propylene carbonate 

 dimethyl carbonate 

 tertiary butyl acetate (TBAc) 

 

After reviewing each of the above compounds, Staff is proposing to amend Rule 101 to include 

HFE-7000, HFE-7500, HFE-7300, methyl formate, dimethyl carbonate and propylene carbonate 

to the list of exempt compounds. These compounds will not adversely impact human health or 

the environment. However, at this time, Staff is not proposing to exempt HFC-227ea or TBAc 

until more information becomes available to adequately determine whether or not these 

compounds will adversely impact human health or the environment. 

In addition, Staff is proposing minor changes to add the common names for two compounds 

already included in Rule 101: HFE-7100 for 1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxy-butane 

(C4F9OCH3) and HFE-7200 for 1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane (C4F9OC2H5). 

BACKGROUND 

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

oxides (NOx) and VOCs in the presence of sunlight. Ozone is a strong irritant that adversely 

affects human health and damages crops and other environmental resources. As documented 

by the EPA in the most recent Criteria Document for ozone1

, both short-term and long-term 

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

 decreased lung function; 

 development and aggravation of asthma; 

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

 increased hospitalizations and emergency room visits; and 

 premature deaths. 

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

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

pollution is to reduce VOC emissions from existing stationary sources by establishing more 

 

1

 “Air Quality Criteria for Ozone and Related Photochemical Oxidants”, U.S. EPA, February 2006. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 2 

stringent VOC emission limits. One method for complying with low VOC emission limits is 

through the use of organic compounds with negligible reactivity for ozone formation, also known 

as exempt compounds. Exempt compounds are listed in Rule 101. 

 

Rule 101 was last amended on September 3, 1998. Since then, EPA has revised the federal 

definition of VOC2

 four times to add eight chemical compounds to the list of exempt compounds. 

This list consists of chemical compounds that are excluded from the federal VOC definition 

based on the compound’s negligible contribution to the formation of ground level ozone. 

Different organic compounds have different levels of reactivity. Some organic compounds do 

not react to form ozone at the same rate or to the same extent as other organic compounds. 

EPA has a policy to exempt organic compounds from the definition of VOC if the compounds 

have negligible levels of reactivity. By exempting non-reactive compounds, EPA helps states 

and air districts focus their efforts on organic compounds that significantly increase ozone 

concentrations. 

 

EPA compares the reactivity of a compound to the reactivity levels of ethane. Compounds with 

reactivity levels less than or equal to the reactivity levels of ethane may be deemed negligibly 

reactive and exempted from the federal definition of VOC. EPA uses three methods to 

determine if a compound is negligibly reactive. The first method is based on the reaction rate 

constant of hydroxyl radical (known as Koh) in the air. This reaction is the first step in a series of 

chemical reactions in the formation of ozone. If this reaction is slow (smaller Koh value), then the 

compound will not likely form ozone at a fast rate. The other two methods are based on the 

maximum incremental reactivity (MIR) expressed either on a reactivity per gram basis (grams of 

ozone formed per gram of VOC) or on a reactivity per mole basis (grams of ozone formed per 

mole of VOC). The MIR methods consider the activities from all steps in the ozone formation 

process from a specific organic compound as opposed to just the first step of the chemical 

reaction. 

Table 1 lists the eight compounds that EPA has added to their exempt list and compares the 

reactivity levels of each compound to that of ethane. It is apparent that propylene carbonate, 

dimethyl carbonate, and tertiary butyl acetate (TBAc) were exempted using the MIR methods, 

since the respective Koh value of each compound was greater than the Koh value of ethane. 

 

 

2

 40 CFR 51.100(s). 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 3 

Table 1: Exempt Compounds 

Federal 

Register 

Reference 

EPA Exempt Compound Koh

MIR 

(mole 

basis) 

MIR 

(mass 

basis) 

Ethane 2.40 x 10-13 8.12 0.27 

69 FR 69290 

1,1,1,2,2,3,3-heptafluoro-3-methoxypropane 

(n-C3F7OCH3 or HFE-7000) 

1.20 x 10-14 ND ND 

69 FR 69290 

3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-

dodecafluoro-2(trifluoromethyl) hexane 

(HFE-7500) 

2.20 x 10-15 ND ND 

69 FR 69290 1,1,1,2,3,3,3-heptafluoropropane 

(HFC-227ea) 1.09 x 10-15 ND ND 

69 FR 69290 methyl formate (HCOOCH3) 2.27 x 10-13 ND 0.053 

72 FR 2193 

1,1,1,2,2,3,4,5,5,5-decafluoro-3-

methoxy-4-trifluoromethyl-pentane 

(HFE-7300) 

1.50 x 10-14 ND ND 

74 FR 3437 propylene carbonate 6.90 x 10-13 27.56 0.27 

74 FR 3437 dimethyl carbonate 3.49 x 10-13 5.04 0.056 

69 FR 69298 tertiary butyl acetate (TBAc) 4.25 x 10-12 27.88 0.24 

ND = Not Determined 

Compounds exempted from the federal VOC definition are not automatically exempted from 

District rules and regulations. The District considers a number of factors, including potential 

uses, impact on human health, and environmental concerns before adding federally-exempt 

compounds to Rule 101. 

LEGAL MANDATES 

Federal Mandates: 

The District is designated “severe” nonattainment for the federal 8-hour ozone standard. In 

February 2009, the districts of the Sacramento Federal Nonattainment Area adopted an 

attainment plan to achieve the federal 8-hour ozone standard by 2018. 

Clean Air Act (CAA) section 172(c)(1) specifies that State Implementation Plans for 

nonattainment areas must include “reasonably available control measures” (RACM), including 

“reasonably available control technology” (RACT), for sources of emissions. 

The proposed amendments to Rule 101 will allow manufacturers and sources more flexibility in 

developing and using low VOC products that may ultimately lead to feasible, lower VOC 

emission limits. 

 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 4 

State Mandates: 

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

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

Section 40919 of the California Health and Safety Code (HSC). 

 California HSC Section 40919 requires districts with serious nonattainment for ozone to 

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

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

reduction achievable, taking into account environmental, energy, and economic impacts 

by each class or category of sources3

. 

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

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

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

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

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

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

An upwind district must comply with the transport mitigation planning and 

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

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

The proposed amendments to Rule 101 will allow manufacturers and sources more exempt 

compounds to use in meeting VOC limits, and this may lead to more stringent and feasible 

BARCT requirements. 

PROPOSED AMENDMENTS 

Staff is proposing to amend Rule 101 to incorporate the following compounds into the list of 

exempt compounds in Section 204: 

 1,1,1,2,2,3,3-heptafluoro-3-methoxy-propane (n-C3F7OCH3 or HFE-7000) 

 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-(trifluoromethyl) hexane (HFE-7500) 

 Methyl formate 

 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-trifluoromethyl-pentane (HFE-7300) 

 Dimethyl carbonate 

 Propylene carbonate 

Each compound is discussed in detail below: 

1,1,1,2,2,3,3-heptafluoro-3-methoxy-propane (n-C3F7OCH3 or HFE-7000): On November 29, 

2004, EPA exempted this compound from the federal definition of VOC because the Koh value of 

HFE-7000 is less than the Koh value of ethane. HFE-7000 may be used as a refrigerant or as 

an aerosol propellant. This compound is classified as a hydrofluoroether (HFE). In general, 

HFEs have an ozone depletion potential (ODP) of zero and may be acceptable substitutes for 

some chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). HFE-7000 is listed 

 

3

 California Health and Safety Code Section 40406. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 5 

as an acceptable replacement for trichlorofluoromethane (CFC-11) and 1,1,2-trichloro-1,2,2-

trifluoroethane (CFC-113) in EPA’s Significant New Alternative Policy (SNAP) program4

. The 

SNAP program evaluates and regulates substitutes for ozone-depleting chemicals that are 

being phased out under the stratospheric ozone protection provisions of the federal Clean Air 

Act. Both CFC-11 and CFC-113 are currently on the District’s list of exempt compounds in Rule 

101. HFE-7000 is estimated to have a global warming potential (GWP) between 140 and 400. 

The GWP of HFE-7000 is low compared to CFC-11 (GWP of 4000) and CFC-113 (GWP of 

5000). 

In a report titled “Risk Screen on the Use of Substitutes for Ozone-Depleting Substances”, EPA 

assessed the potential health impacts of including HFE-7000 in EPA’s SNAP Program5

. The 

study screened the potential risks to workers for occupational exposure and to the general 

public from exposure of ambient air releases of HFE-7000. EPA determined that the exposure 

of HFE-7000 to workers and the general population is expected to be below the level of concern 

for non-cancer risk. In addition, according to the final rule to exempt four compounds from the 

definition of VOC as published in the Federal Register6

, HFE-7000 is very similar in structure, 

toxicity, and atmospheric properties to other HFE compounds such as C4F9OCH3 (HFE-7100) 

and C4F9OC2H5 (HFE-7200). In March 2008, CARB conducted an Environmental Impact 

Assessment of Selected Halogenated Chemicals, where HFE-7100 and HFE-7200 were among 

the seven compounds that were evaluated. CARB determined that HFE-7100 and HFE-7200 

are not chemical carcinogens to humans and have an acute and chronic Hazard Index of less 

than 17

, which indicates no adverse human health effects are expected to occur. Staff expects 

HFE-7000 to have low health impacts, similar to that of HFE-7100 and HFE-7200. 

Staff is proposing to exempt HFE-7000 from the District’s definition of VOC because this 

compound would not have an adverse impact on human health or the environment. In addition, 

this compound may have significant benefits to stratospheric ozone depletion and global 

warming concerns. 

3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-(trifluoromethyl) hexane (HFE-7500): On 

November 29, 2004, EPA exempted this compound from the federal definition of VOC because 

the Koh value of HFE-7500 is less than the Koh value of ethane. HFE-7500 may be used as a 

refrigerant. Similar to HFE-7000, this compound is classified as a HFE and has an ODP of 

zero. In EPA’s SNAP program, HFEs, as a class, have been identified as possible substitutes 

for CFCs. HFE-7500 is estimated to have a GWP of 100. The GWP of HFE-7500 is low 

compared to CFCs. In general, CFCs have very high GWPs, usually greater than 1,000. 

The Product Specification Sheet published by 3M stated that HFE-7500 has a very low overall 

toxicity. The Product Specification Sheet also indicated that the compound will cause minimal 

irritation to the skin and eyes when in contact with the material, and in a 28-day oral toxicity 

study, no adverse effects were observed. In addition, according to the final rule to exempt four 

 

4

 ”Protection of Stratospheric Ozone: Notice 16 for Significant New Alternatives Policy Program,” Federal 

Register, Volume 67, March 2, 2002, p. 13272 – 13278. 

5

 “Risk screen on the use of substitutes for ozone-depleting substances,” U.S. EPA, August 21, 2003. 6

 “Air Quality: Revision to Definition of Volatile Organic Compounds – Exclusion of Four Compounds,” 

Federal Register, Volume 69, November 29, 2004, p. 69290 – 69298. 

7

 “Environmental Impact Assessment of Selected Halogenated Chemicals,” CARB, March 2008, p. 18 – 

19. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 6 

compounds from the definition of VOC as published in the Federal Register8, HFE-7500 is very 

similar in structure, toxicity and atmospheric properties to other HFE compounds such as HFE7100 and HFE-7200. As previously discussed, HFE-7100 and HFE-7200 are not expected to 

adversely impact human health, and Staff expects that HFE-7500 will have similarly low impacts 

on human health. 

Staff is proposing to exempt HFE-7500 from the District’s definition of VOC because this 

compound would not have an adverse impact on human health or the environment. In addition, 

this compound may have significant benefits to stratospheric ozone depletion and global 

warming concerns.

Methyl formate (HCOOCH3): On November 29, 2004, EPA exempted this compound from the 

federal definition of VOC because the Koh value of methyl formate is less than the Koh value of 

ethane. This compound is used to manufacture formamides and formic acid. Because of its 

high vapor pressure, it may be used as a component for quick-drying finishes. It is also used as 

a blowing agent in foam manufacturing processes, where it may be a replacement for butane, 

pentane, and some HCFCs. Butane and pentane are VOCs with much higher reactivity than 

methyl formate. In general, HCFCs have ODPs ranging from 0.01 to 0.1 and GWPs ranging 

from 93 to 2000. Methyl formate has a negligible ODP and a very low or zero GWP. 

In a May 19, 2008 letter to all Air Pollution Control Officers, CARB shared the results of its 

analysis prepared with assistance from the Office of Environmental Health Hazard Assessment 

(OEHHA). Methyl formate is hydrolyzed in the body to methanol and formic acid. Methanol can 

be enzymatically oxidized to formaldehyde. Because of its metabolites, methyl formate may be 

considered toxic. It can cause irritation to the eyes, skin, lungs, and at high exposure levels, it 

may cause pulmonary damage. After a review of methyl formate and its metabolites, OEHHA 

derived an interim acute non-cancer reference exposure level (REL) of 11,400 ug/m3

 that is 

considered to be protective of nearby receptors. No data were available on long term inhalation 

exposure of methyl formate, so a chronic REL could not be developed. Also, OEHHA 

determined that there is no evidence of carcinogenicity for methanol, despite a robust database 

on its toxicity and a long history of human exposure. In a memo to CARB, OEHHA concluded 

that at doses likely to be achieved in environmental exposures by inhalation, the toxicity concern 

appears to be minor. Based on OEHHA’s conclusions, CARB recommended that methyl 

formate should be exempted from the definition of VOC, based on its low reactivity and the 

positive environmental benefits that may result if methyl formate displaces the use of other 

foam-blowing agents. CARB also recommended that the districts consider the impacts of 

exempting methyl formate, including the substances that it will likely replace the amount and 

nature of use, and the estimated population exposures and indoor exposure resulting from use.

The uses of methyl formate are as a foam blowing agent and as a component in quick-drying 

finishes. Currently, the District does not have any foam blowing operations, which are typically 

large operations. If, in the future, a foam blowing plant is proposed in the District, it would 

undergo extensive reviews under the District’s permitting process, which includes a toxics 

review. These reviews will ensure that the operation complies with local, state, and federal 

rules and regulations, and that the risk to the public is acceptable. 

 

8

 “Air Quality: Revision to Definition of Volatile Organic Compounds – Exclusion of Four Compounds,” 

Federal Register, Volume 69, November 29, 2004, p. 69290 – 69298. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 7 

Additionally, if methyl formate is exempted from the District’s VOC definition, its use as a 

component in quick-drying finishes may increase. It is necessary to ensure that in these 

applications, the increased use of methyl formate does not result in an unacceptable toxic risk. 

As such, Staff calculated the maximum emission of methyl formate that will cause adverse 

impact to human health. Generally, a hazard index of less than 1 is not considered to be a 

significant concern to human health at a nearby receptor. Staff used the Bowman 

Environmental Engineering Short Term (BEEST) for Windows modeling program, version 9.63, 

to determine the unit emission rate concentration from a point source (emissions exhausted 

from a stack) and volume source (emissions vented from a building) necessary to reach an 

acute hazard index of 1. The specific details and modeling assumptions are summarized in 

Appendix B and the modeling results are shown in the following table. 

Table 2: Acute Impacts for Methyl Formate 

Source Type 

Unit Emission 

Rate 

1-hour Conc. 

(ug/m3

)/(g/s) 

Acute 

Hazard 

Index 

Acute REL 

(ug/m3

) 

Emission Rate 

(g/s) 

Hourly MF 

Emissions 

(lb/hour) 

Point 1,080 1 11,400 10.5 83.6 

Volume 21,700 1 11,400 0.53 4.16 

Emission Rate, g/s = (Acute REL, ug/m3)/(Unit Emission Rate Conc. (ug/m3)/(g/s)) 

Hourly emissions, lb/hr = emission rate, g/s * 0.0022 lb/g * 3600 s/hr 

To ensure that the hazard index is less than 1, the hourly emission rate of methyl formate from a 

point source should be less than 83.6 pounds per hour. To assess the significance of the hourly 

emissions, Staff compared the calculated hourly emissions to actual VOC emissions from the 

largest coating facility in District. According to the 2009 Emission Inventory, the largest coating 

facility, which is a point source, emits approximately 15,000 pounds of VOC per year. Assuming 

that the facility operates 8 hours per day, 5 days per week, and 52 weeks per year, the average 

hourly VOC emission for the facility would be approximately 7.2 pounds per hour. From this 

comparison, Staff can conclude that it is very unlikely that methyl formate emissions will be 

greater than 83.6 pounds per hour from a point source within the District, even if 100% of the 

VOC is replaced by methyl formate. 

For a volume source, the estimated maximum concentration is located approximately 10 meters 

from the emission source, which is considered the worst-case scenario. To ensure that the 

hazard index is less than 1, the hourly emission rate of methyl formate from a volume source 

should be less than 4.16 pounds per hour. Volume sources are usually small operations; 

however, as a worst-case estimate, Staff assumed that the largest coating facility in the District 

is a volume source. As previously determined, the average hourly emission from the largest 

coating facility is 7.2 pounds of VOC per hour. Since methyl formate is used as one of multiple 

components, its emissions from quick-drying finishes depend on the percentage of methyl 

formate used in the products. To exceed the hazard index of 1, methyl formate emissions 

would need to be 58% of the total VOC emissions to emit 7.2 pounds of VOC per hour. Based 

on CARB’s Environmental Impact Assessment of tertiary-butyl acetate, the total emissions of 

xylene, toluene, or MEK from coating operations are 61% to 80% of the total VOC emissions9

. 

Methyl formate, a much faster evaporating compound with a vapor pressure of 476 mm Hg at 

20°C, would not be a suitable replacement for compounds such as xylene, toluene, and MEK 

that are slower evaporating VOCs with vapor pressures ranging from 9 mm Hg at 20°C to 79 

 

9

 “Environmental Impact Assessment of Tertiary-Butyl Acetate” CARB, January 2006, p. 30. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 8 

mm Hg at 20°C10. Assuming methyl formate is used to replace compounds other than xylene, 

toluene, or MEK, methyl formate emissions would only be as high as 39% of the total VOC 

emissions, which is less than the emissions needed to exceed the hazard index of 1. 

Staff also reviewed the most recent inspection reports available and found that the largest 

quarterly emission from a coating volume source in 2010 was 989 pounds of VOC per quarter. 

Assuming that the facility operates 8 hours per day, 5 days per week, and 13 weeks per quarter, 

the average hourly VOC emission for the facility would be approximately 1.9 pounds per hour, 

which is less than emissions needed to exceed the hazard index of 1 even if 100% of the VOC 

is replaced by methyl formate. 

In addition, according to the American Coating Association, the use of methyl formate in 

coatings is a small fraction of solvents used in a coating because methyl formate is flammable 

and dries too quickly11. Therefore, Staff can conclude that it is very unlikely that methyl formate 

emissions will be greater than 4.16 pounds per hour at a coating operation volume source within 

the District. 

Staff is proposing to exempt methyl formate from the District’s definition of VOC because it is 

unlikely to cause adverse impacts to human health or the environment. 

1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-trifluoromethyl-pentane (HFE-7300): On 

January 18, 2007, EPA exempted this compound from the federal definition of VOC because 

the Koh value of HFE-7300 was less than the Koh value of ethane. HFE-7300 may be used in a 

variety of applications, including heat transfer, lubricant deposition, electronic testing and 

cleaning applications. Similar to HFE-7000 and HFE-7500, this compound is classified as a 

HFE and has an ODP of zero. Under EPA’s SNAP program, HFEs, as a class, have been 

identified as possible substitutes for CFCs. According to EPA’s analysis, HFE-7300 could be 

used to reduce GHG by substituting for other compounds with higher GWP, such as replacing 

CFCs. 

The Product Specification Sheet published by 3M indicates that HFE-7300 has low toxicity. In 

addition, according to the final rule to exempt HFE-7300 from the definition of VOC as published 

in the Federal Register12, HFE-7300 is very similar in structure, toxicity and atmospheric 

properties to other HFE compounds such as HFE-7100 and HFE-7200. As previously 

discussed, HFE-7100 and HFE-7200 are not expected to adversely impact human health, and 

Staff expects that HFE-7300 will have similarly low impacts on human health. 

Staff is proposing to exempt HFE-7300 from the District’s definition of VOC because this 

compound would not have an adverse impact on human health or the environment. In addition, 

this compound may have significant benefits to stratospheric ozone depletion concerns.

Dimethyl carbonate: On January 21, 2009, EPA exempted this compound from the federal 

definition of VOC based on the MIR methods. The MIRs of dimethyl carbonate on a mass and 

mole basis were lower than those of ethane. This compound is used as a co-solvent in paints, 

 

10 Center for Disease Control and Prevention, http://www.cdc.gov/niosh/npg/default.html, (accessed on 

9/21/2011). 

11 E-mail correspondence with David Darling, American Coating Association, September 21, 2011 12 “Air Quality: Revision to Definition of Volatile Organic Compounds – Exclusion of HFE-7300,” Federal 

Register, Volume 72, January 18, 2007, p. 2193 – 2196. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 9 

sealants, adhesives, and as a multi-purpose and thinning solvent. Dimethyl carbonate may 

also be used as a niche or specialty solvent in industrial coating/sealant applications. For some 

cleaning applications, dimethyl carbonate may be used as a substitute for isopropyl alcohol. 

This compound has an ODP and GWP of zero. 

In December of 2009, OEHHA completed a toxicity assessment on dimethyl carbonate. 

Dimethyl carbonate is hydrolyzed to carbon dioxide and methanol in the body via esterase. 

Methanol is metabolized to formaldehyde, which is further oxidized to formic acid. Because of 

its metabolites, dimethyl carbonate may be considered toxic. To be protective of nearby 

receptors from the use of dimethyl carbonate, OEHHA derived an interim acute REL of 18,000 

ug/m3

 and chronic REL of 5,500 ug/’m3. OEHHA has determined that there is no evidence of 

carcinogenicity for methanol, the primary metabolite of dimethyl carbonate, despite a robust 

database on its toxicity and a long history of human exposure. OEHHA has also determined 

that the proposed interim acute and chronic RELs are expected to be protective of anticipated 

effects, including developmental toxicity observed in a key study reported for dimethyl 

carbonate. Additionally, in OEHHA’s memo to CARB13, OEHHA finds that the exposure to the 

general public near facilities using dimethyl carbonate will occur, and, at dose levels likely to be 

achieved by inhalation from the general public, the toxicity impact from the use of this 

compound appears to be relatively minor. 

According to Kowa American Corporation, a manufacturer and distributor of chemical 

compounds, dimethyl carbonate may be substituted for fast evaporating compounds used in 

paints, sealants, adhesives and multi-purpose and thinning solvents. Dimethyl carbonate may 

replace other non-exempt compounds such as xylene, toluene, methyl ethyl ketone (MEK) and 

hexane that have been identified as Toxic Air Contaminants by CARB. Dimethyl carbonate may 

replace non-exempt compounds like ethyl acetate or isopropanol. Dimethyl carbonate may also 

be a better alternative to some exempt compounds such as acetone and methyl acetate. 

Because of the low flash point of acetone and methyl acetate, using dimethyl carbonate in 

coating formulations helps lower the risk of fires or explosions. Acetone and methyl acetate 

have flash points of -20 °C and -10 °C, respectively, whereas dimethyl carbonate has a flash 

point of 17 °C. 

If dimethyl carbonate is exempted from the District’s definition of VOC, its use in the potential 

applications discussed above may increase. To ensure that the increased uses of dimethyl 

carbonate do not adversely impact human health, Staff calculated the maximum usages for 

dimethyl carbonate that would result in hazard indices less than 1 using the same dispersion 

methodology used for methyl formate. The specific details and modeling assumptions are 

summarized in Appendix B, and the modeling results are shown in Table 3 for acute impacts 

and Table 4 for chronic impacts. 

 

 

13 “Revised Assessment of Health Effects of Exposure to Dimethyl Carbonate, A Chemical Petitioned for 

Exemption from VOC Rules,” Memorandum from OEHHA to Air Resources Board, December 8, 2009. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 10 

Table 3: Acute Impacts for Dimethyl Carbonate 

Source Type 

Unit Emission 

Rate 

1-hour Conc. 

(ug/m3

)/(g/s) 

Acute 

Hazard 

Index 

Acute REL 

(ug/m3

) 

Emission Rate 

(g/s) 

Hourly DMC 

Emission 

(lb/hour) 

Point 1,080 1 18,000 16.6 132 

Volume 21,700 1 18,000 0.83 6.58 

Emission Rate, g/s = (Acute REL, ug/m3)/(Unit Emission Rate Conc. (ug/m3)/(g/s) 

Hourly emissions, lb/hr = emission rate, g/s * 0.0022 lb/g * 3600 s/hr 

The maximum hourly emission rate for dimethyl carbonate for a point source to ensure that the 

acute hazard index is less than 1 is 132 pounds per hour. As previously determined, the largest 

coating facility in the District emits an average of 7.2 pounds of VOC per hour. Staff can 

conclude that it is unlikely for point source facility to emit more than 132 pounds of dimethyl 

carbonate per hour. 

For a volume source, the estimated maximum concentration is located approximately 10 meters 

from the emission source, which would be considered a worst-case scenario. The maximum 

hourly emission rate for a volume source to ensure that the acute index is less than 1 is less 

than 6.58 pounds per hour. As a potential solvent component in paint, sealant, and adhesive, 

dimethyl carbonate may replace xylene, toluene, and MEK. Based on CARB’s Environmental 

Impact Assessment of tertiary-butyl acetate, the total emissions of xylene, toluene and MEK are 

as high as 80% of the total VOC emissions from coatings14. Assuming that 100% of xylene, 

toluene and MEK are replaced by dimethyl carbonate, the VOC emissions and the emissions 

from dimethyl carbonate from coating facility would need to be more than 8.2 pounds of VOC 

per hour to exceed the acute hazard index of 1. As previously determined, the largest coating 

facility in the District emits an average of 7.2 pounds of VOC per hour. Therefore, Staff can 

conclude that it is unlikely that a volume source would emit more than 6.58 pounds of dimethyl 

carbonate per hour. 

Table 4: Chronic Impacts for Dimethyl Carbonate 

Source Type 

Unit Emission 

Rate 

Annual Conc. 

(ug/m3

)/(g/s) 

Chronic 

Hazard 

Index 

Chronic 

REL 

(ug/m3

) 

Emission Rate 

(g/s) 

Annual DMC 

Emission 

(lb/year) 

Point 95.1 1 5,500 57.8 954,000 

Volume 1,880 1 5,500 2.93 48,300 

Emission Rate, g/s = (Acute REL, ug/m3)/(Unit Emission Rate Conc. (ug/m3)/(g/s) 

Annual emissions, lb/year = emission rate, g/s * 0.0022 lb/g * 3600 s/hr * 8 hr/day * 5 day/wk * 52 wk/yr 

The maximum emission rate for dimethyl carbonate for a point source to ensure that the chronic 

hazard index is less than 1 is 57.8 grams per second. Based 8 hours per day, 5 days a week, 

and 52 weeks per year of operation, the emission rate is equivalent to 954,000 pounds per year. 

For a volume source, the estimated maximum concentration is located approximately 10 meters 

 

14 “Environmental Impact Assessment of Tertiary-Butyl Acetate” CARB, January 2006, p. 30. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 11 

from the emission source, which would be considered a worst-case scenario. The maximum 

emission rate for a volume source is 2.93 grams per second, which is equivalent to 48,300 

pounds of dimethyl carbonate per year. As previously determined, the largest coating facility in 

the District emits approximately 15,000 pounds of VOC per year according to the 2009 Emission 

Inventory. Therefore, Staff can conclude that it is highly unlikely for a facility to use amounts 

that would result in a chronic hazard index greater than 1. 

Staff is proposing to exempt dimethyl carbonate from the District’s definition of VOC because it 

will not cause adverse impact to human health or the environment. 

Propylene carbonate: On January 21, 2009, EPA exempted this compound from the federal 

definition of VOC based on the MIR method. The MIR of propylene carbonate on a mole basis 

was lower than that of ethane. This compound has been used in adhesives, paint strippers, and 

as a solvent for aerial pesticide applications. This compound is also used in cosmetics, lip 

liners, baby lotions, shampoos, special purpose lubricants, general purpose degreasers, 

rubberized coatings, and painting products. It is allowed to be used in cosmetic products at 

concentrations up to 20%. It also has an ODP and a GWP of zero. 

In June of 1998, EPA completed a study entitled, “Environmental Profile for Propylene 

Carbonate,” which evaluated the environmental impacts of using propylene carbonate. This 

study found that propylene carbonate causes mild skin and eye irritation but it is not known to 

be a reproductive toxin, a mutagen, or a carcinogen. The study also concluded that propylene 

carbonate poses minimal risk to workers and residential populations based on the low order of 

toxicity, low rate of skin absorption, low volatility and low environmental persistence. No acute 

or chronic RELs have been assigned to propylene carbonate. However, as noted in the EPA 

study, rats exposed to very high aerosol concentrations (up to 106

 ug/m3) over a 90-day period 

showed no significant signs of toxic effects, except for some swelling around the eyes at the 

higher concentrations. 

Staff is proposing to exempt propylene carbonate from the District’s definition of VOC because 

this compound would not have an adverse impact on human health or the environment. In 

addition, this compound may have significant benefits to stratospheric ozone depletion and 

global warming concerns. 

Minor Changes to Rule 101 

Staff is proposing minor changes that add the common names for two compounds already 

included in Rule 101: HFE-7100 for 1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxy-butane (C4F9OCH3) 

and HFE-7200 for 1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane (C4F9OC2H5). 

 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 12 

EPA EXEMPT COMPOUNDS NOT RECOMMENDED FOR DISTRICT EXEMPTION 

In addition to the compounds discussed above, EPA has exempted HFC-227ea and TBAc from 

the federal definition VOC. Staff, however, is not proposing to incorporate these compounds 

into the District’s list of exempt compounds either because Staff does not have adequate 

information to evaluate these compounds, or has concerns regarding the adverse impact to 

human health or the environment. Staff may recommend exempting these compounds in the 

future when more information becomes available and/or additional health and environmental 

assessment has been completed. Each compound is discussed below. 

1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea): On November 29, 2004, EPA exempted this 

compound from the federal definition of VOC because the Koh value of HFC-227ea is less than 

the Koh value of ethane. This compound may be used as a fire suppressant or aerosol 

propellant. This compound is classified as a hydrofluorocarbon (HFC). In general, HFCs have 

an ODP of zero, and this compound may be an acceptable substitute for CFCs. Some HFCs 

have high GWPs. HFC-227ea has GWP of 3800 and could be used to replace other 

compounds with either higher or lower GWPs. In various fire suppression applications, HFC227ea may be used as a replacement for Halon 1301, with a GWP (6900) that is higher than 

HFC-227ea or Halon 1211, with a GWP (1300) that is lower than HFC-227ea. 

HFC-227ea is listed as a potent greenhouse gas and would contribute to global warming if used 

as a replacement for compounds with lower GWPs. This compound could potentially have an 

adverse impact on the environment. Furthermore, Staff has not received a request to exempt 

this compound and does not recommend it for exemption at this time. 

Tertiary butyl acetate (TBAc): On November 29, 2004, EPA exempted TBAc from the federal 

definition of VOC in Title 40, Part 51 of the Code of Federal Regulation for the purpose of 

complying with VOC emission limitations or VOC content requirements. However, EPA 

maintained TBAc as a VOC for the purposes of all recordkeeping, emissions reporting, 

photochemical modeling, and emissions inventory requirements. This compound may be used 

in a variety of coatings, cleaning solvents, and degreasers. 

In 2006, CARB, with assistance from the Office of Environmental Health Hazard Assessment 

(OEHHA), conducted an environmental impact assessment of TBAc. CARB determined that the 

increased use of TBAc is not expected to increase depletion of stratospheric ozone or contribute 

to global warming. CARB also concluded that TBAc could pose a potential cancer risk to 

humans because TBAc metabolizes to tertiary butyl alcohol (TBA). TBA is a potential 

carcinogen that may result in a cancer risk to humans. Because TBAc may be a carcinogen, 

OEHHA developed an interim inhalation unit risk factor for TBAc of 4x10-7 (ug/m3

)

-1. CARB 

recommended that the air districts determine whether the use of TBAc in certain products would 

pose an unacceptable exposure. 

 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 13 

Staff calculated the maximum emissions of TBAc that will cause adverse impact to human 

health. Generally, a cancer risk of less than 10 in a million per facility for a nearby receptor is 

below the threshold of significance and considered acceptable based on SMAQMD threshold of 

significance for the California Environmental Quality Act (CEQA). Staff used the BEEST for 

Windows modeling program, version 9.63, to determine the unit emission rate concentration 

from a point source and volume source necessary to reach a cancer risk of 10 in a million. The 

specific detail and modeling assumptions are summarized in Appendix B and the modeling 

results are shown in the following table. 

Table 5: TBAc Emissions Impact on Nearby Receptors 

Source Type 

Unit Emission 

Rate 

Annual Conc. 

(ug/m3

)/(g/s) 

Inhalation 

Unit Risk 

Factor 

(ug/m3)

-1

Cancer 

Risk 

(per 106

Cases) 

Emission Rate 

(g/s) 

Annual TBAc 

Emissions 

(lb/year) 

Point 95.1 4 x 10-7 10 0.26 4,340 

Volume 1,880 4 x 10-7 10 0.01 220 

Emission Rate, g/s = Cancer Risk/[(Unit Emission Rate (ug/m3)/(g/s) * (Inhalation Unit Risk Factor (ug/m3)

-1] 

Annual emissions, lb/year = emission rate, g/s * 0.0022 lb/g * 3600 s/hr * 8 hr/day * 5 day/wk * 52 wk/yr 

For a coating operation, a point source facility is a facility that sprays paint inside a spray booth 

and the emissions are exhausted through a stack. The maximum emission rate for TBAc from a 

point source to ensure that the cancer risk is less than 10 in a million is 0.26 grams per second. 

This emission rate is equivalent to 4,340 pounds per year, assuming the operation is 8 hours 

per day, 5 days per week, and 52 weeks per year. In CARB’s Environmental Impact 

Assessment of Tertiary-butyl Acetate, CARB determined that TBAc may be used to replace 

xylene, toluene, and MEK in coatings. The total emissions of xylene, toluene and MEK are as 

high as 80% of the total VOC emissions from coatings15. Assuming that 100% of xylene, 

toluene and MEK are replaced by TBAc, the VOC emissions, including TBAc emissions, from 

the coating facility would need to be more than 5,425 pounds per year to exceed the cancer risk 

of 10 in a million. 

As previously determined, the largest coating facility in the District emits approximately 15,000 

pounds of VOC per year. In addition, according to District permit database, there are many 

other point source coating facilities that have the potential to emit more than 5,425 pounds of 

VOC per year. 

The use of TBAc in coatings or as solvents may not occur in a paint spray booth. A volume 

source technique in the BEEST model evaluates these facilities where coating or solvent use 

does not occur in a spray booth, and the emissions are exhausted through ground level 

openings in the building, e.g. doors and windows, not through an exhaust stack. The maximum 

emission rate for a volume source to ensure that the cancer risk is less than 10 in a million is 

0.01 grams per second, which is equivalent to 220 pounds of TBAc per year assuming the 

operation is 8 hours per day, 5 days per week, and 52 weeks per year. If TBAc is assumed to 

replace 80% of the VOC, the VOC emissions, including TBAc, would need to be more than 275 

pounds per year to exceed the cancer risk of 10 in a million. 

 

15 “Environmental Impact Assessment of Tertiary-Butyl Acetate” CARB, January 2006, p. 30. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 14 

To assess the significance of the emissions from a volume source, Staff compared the 

calculated annual TBAc emissions to District’s exemption threshold for coating operations. Rule 

201 – General Permit Requirements exempts coating operations that use less than 1 gallon per 

day of coating materials and solvents from the requirement to obtain a permit. The analysis 

considered an unpermitted facility without a spray booth using the amount of coatings allowed 

under the exemption, (just under) 1 gallon per day, for 5 days per week and 52 weeks per year. 

This is equivalent to 260 gallons of coatings per year. At 260 gallons per year, a volume source 

would need to use coatings with an average VOC content of 1.1 pounds per gallon or more to 

emit VOC emissions that would exceed the cancer risk threshold. For comparison purposes, 

the average VOC content for automotive refinishing coatings is 4.5 pounds per gallon16. Since 

TBAc can be used in a variety of coatings and solvents, Staff can conclude that it is likely the 

average VOC content of coatings and solvents could be more than 1.1 pounds per gallons. 

Staff concludes that TBAc may be emitted in quantities that would exceed a cancer risk of 10 in 

a million and may potentially cause an adverse impact to receptors near facilities using TBAc. 

At this time, Staff is proposing that TBAc not be an exempt compound for all uses in the District. 

Instead, Staff will evaluate TBAc on a rule-by-rule basis to determine the need to exempt TBAc 

and the potential health impact of TBAc to nearby receptors. If TBAc is needed to formulate 

compliant products and the health impact is less than significant, Staff may consider exempting 

TBAc within specific prohibitory rules. 

To date, no studies have been conducted to assess the carcinogenicity of TBAc itself, only its 

metabolite, TBA. If future studies of TBAc demonstrate lower cancer risk than that used in this 

analysis, Staff may reconsider a general exemption of TBAc. 

SOCIOECONOMIC IMPACT ANALYSIS 

The provisions of Section 40728.5 of the California Health and Safety Code require, in part, that: 

"Whenever a district intends to propose the adoption, amendment, or repeal of a rule or 

regulation that will significantly affect air quality or emissions limitations, that agency 

shall, to the extent that data are available, perform an assessment of the socioeconomic 

impacts of the adoption, amendment, or repeal of the rule or regulation...This section 

does not apply to the adoption, amendment, or repeal of any rule or regulation that 

results in any less restrictive emissions limit if the action does not interfere with the 

district’s adopted plan to attain ambient air quality standards, or does not result in any 

significant increase in emissions." 

The proposed amendments to Rule 101 update the District’s list of exempt compounds to 

include six compounds that were exempted by EPA. These amendments do not establish 

emission limitations, and because these compounds have negligible reactivity, their exemption 

will not significantly affect air quality. The proposed amendments will not interfere with the 

District’s adopted plan to attain the ambient air quality standards. Therefore, the provisions of 

Section 40728.5 of the Health and Safety Code do not apply to the proposed amendments to 

Rule 101, and a socioeconomic impact analysis is not required.

 

16 Ibid, p. 36. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 15 

PUBLIC COMMENTS 

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

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

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

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

receive rulemaking notices. The notice was also published in the “Our Region” section of the 

Sacramento Bee and posted on the District web site. The draft rule and staff report were 

available for public review prior to the public workshop. 

Staff received comments and questions concerning Rule 101 at the workshop, as well as written 

comments from chemical manufacturers and distributors, coating manufacturers and 

distributors, and a coating association. CARB and EPA reviewed the proposed amendments, 

and EPA had an editorial comment. All comments and responses to comments are included in 

Appendix C. 

Several written comments were received requesting Staff to consider an exemption for TBAc as 

a VOC. Some comments further requested that if Staff was unwilling to grant a full exemption 

for TBAc, then exempt TBAc with the same permitting requirement proposed for dimethyl 

carbonate and methyl formate. Staff had initially proposed to exempt dimethyl carbonate and 

methyl formate with restrictions that required a facility to submit a permit application if the facility 

would use more than 1 gallon of dimethyl carbonate or methyl formate. Staff is no longer 

proposing to add these additional permitting requirements for dimethyl carbonate and methyl 

formate because Staff performed a health risk assessment and determined that it is unlikely that 

the use of these compounds would adversely impact human health. Staff performed a health 

risk assessment for TBAc and determined that the use of TBAc may impact human health at 

nearby receptors at the facilities using TBAc. Furthermore, TBAc is a potential carcinogen, 

whereas dimethyl carbonate and methyl formate are not. Therefore, Staff is not proposing to 

exempt TBAc as a VOC in Rule 101 but will evaluate TBAc on a rule-by-rule basis as rules are 

adopted or amended so that an evaluation of the need of the exemption and health impacts can 

be assessed. Staff may reconsider an exemption at a later time when CARB or OEHHA has 

determined that TBAc will not adversely impact human health. 

ENVIRONMENTAL REVIEW AND COMPLIANCE 

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

reasonably foreseeable methods of compliance. Proposed amendments to Rule 101 will add 

six organic compounds to the list of exempt compounds and will not establish emission 

limitations; however, these compounds may be used to comply with VOC limits in other District 

rules. Staff reviewed the six compounds and determined that the compounds have negligible or 

zero ODPs. Also, each compound either has a low GWP or would be used to replace other 

organic compounds with higher GWPs. Where the compounds have toxicity concerns, Staff 

performed health risk assessments to ensure that the potential increased use of the compounds 

will not cause an adverse impact to nearby receptors. The proposed amendments will not 

cause any other significant adverse effects on the environment and will not increase emissions; 

therefore, Staff has concluded that no environmental impacts will be caused by the proposed 

amendments. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 16 

Staff finds that the proposed rule amendments are exempt from CEQA because it can be seen 

with certainty that there is no possibility that the activity in question may have a significant 

adverse effect on the environment17. 

FINDINGS 

Finding Finding Determination 

Authority: The District must find that a 

provision of law or of a state or federal 

regulation permits or requires the District to 

adopt, amend, or repeal the rule. 

The District is authorized to adopt and amend Rule 

101 by California Health and Safety Code (HSC) 

Sections 40001, 40702, and 41010. [HSC Section 

40727(b)(2)]. 

Necessity: The District must find that the 

rulemaking demonstrates a need exists for the 

rule, or for its amendment or repeal. 

The proposed amendments to Rule 101 are 

necessary to incorporate six compounds exempted 

by EPA into the District’s definition of VOC. This 

will give manufacturers and sources more flexibility 

in formulating and using products with low VOC 

limits. [HSC Section 40727(b)(1)]. 

Clarity: The District must find that the rule is 

written or displayed so that its meaning can be 

easily understood by the persons directly 

affected by it. 

Staff has reviewed the proposed rule amendments 

and determined that they can easily be understood 

by the affected parties. In addition, the record 

contains no evidence that the persons directly 

affected by the rule cannot understand it. [HSC 

Section 40727(b)(3)]. 

Consistency: The rule is in harmony with, and 

not in conflict with or contradictory to, existing 

statutes, court decisions, or state or federal 

regulations. 

The proposed amendments to the rule do not 

conflict with and are not in contradictory to existing 

statutes, court decisions, or state or federal 

regulations. [HSC Section 40727(b)(4)]. 

Non-Duplication: The District must find that 

either: 1) The rule does not impose the same 

requirements as an existing state or federal 

regulation; or (2) that the duplicative 

requirements are necessary or proper to 

execute the powers and duties granted to, and 

imposed upon the District. 

The proposed amendments to the rule do not 

duplicate any existing state or federal laws or 

regulations. [HSC Section 40727(b)(5)]. 

Reference: The District must refer to any 

statute, court decision, or other provision of law 

that the District implements, interprets, or 

makes specific by adopting, amending or 

repealing the rule. 

Health and Safety Code Sections 40001, 40702, 

and 41010. [HSC Section 40727(b)(6)]. 

Additional Informational Requirements: In 

complying with HSC Section 40727.2, the 

District must identify all federal requirements 

and District rules that apply to the same 

equipment or source type as the proposed rule 

or amendments. 

The amendments to Rule 101 incorporate 

additional compounds into the list of exempt 

compounds and will not require limits on VOC 

emissions. Therefore, a written analysis of federal 

regulations and other District rules is not required. 

[HSC Section 40727.2(g)]. 

 

17 State CEQA Guidelines, Section 15061(b)(3). 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 17 

REFERENCES 

3M Company. “Product Information: 3M Novec 7300 Engineered Fluid.” September 2009 

3M Company. “Product Information: 3M Novec 7500 Engineered Fluid.” September 2009 

American Coating Association, e-mail from David Darling, American Coating Association, to 

Kevin J. Williams, SMAQMD, September 21, 2011. 

California Air Resources Board. “Environmental Impact Assessment of Tertiary-Butyl Acetate.” 

January 2006. 

California Air Resources Board. “Environmental Impact Assessment of Selected Halogenated 

Chemicals.” March 2008. 

California Air Resources Board. Letter to Air Pollution Control Officers regarding methyl formate 

assessment. May 19, 2008. 

Kowa American Corporation. Dimethyl Carbonate Information Request submitted to U.S. 

Environmental Protection Agency. Modified January 2010. 

Office of Environmental Health Hazard Assessment. Memorandum to Air Resources Board, 

“Revised Assessment of Health Effects of Exposure to Dimethyl Carbonate, A Chemical 

Petitioned for Exemption from VOC Rules”. December 8, 2009. 

San Joaquin Valley Unified Air Pollution Control District. Final Draft Staff Report: Proposed 

Amendments to Rule 1020 (Definitions). December 18, 2008 

South Coast Air Quality Management District. Final Staff Report for Proposed Amended Rule 

102 – Definition of Terms. September 2009. 

U.S. Environmental Protection Agency. 40 CFR Part 51.100(s)(1) Definition of Volatile Organic 

Compound. 

U.S. Environmental Protection Agency. “Environmental Profile for Propylene Carbonate”, 

EPA/600/R-98/068. June 1998. 

U.S. Environmental Protection Agency. Federal Register, 67 FR 13272: “Protection of 

Stratospheric Ozone: Notice 16 for Significant New Alternatives Policy Program.” March 22, 

2002. 

U.S. Environmental Protection Agency. “Risk Screen on the Use of Substitutes for OzoneDepleting Substances: Aerosols and Solvents.” August 21, 2003. 

U.S. Environmental Protection Agency. Federal Register, 69 FR 69290: “Air Quality: Revision 

to Definition of Volatile Organic Compounds – Exclusion of Four Compounds.” November 29, 

2004. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 18 

U.S. Environmental Protection Agency. Federal Register, 69 FR 69298: “Revision to Definition 

of Volatile Organic Compounds – Exclusion of t-Butyl Acetate.” November 29, 2004. 

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

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

U.S. Environmental Protection Agency. Federal Register, 72 FR 2193: “Air Quality: Revision to 

Definition of Volatile Organic Compounds – Exclusion of HFE-7300.” January 18, 2007. 

U.S. Environmental Protection Agency. Federal Register, 74 FR 3437: “Air Quality: Revision to 

Definition of Volatile Organic Compounds – Exclusion of Propylene Carbonate and Dimethyl 

Carbonate.” January 21, 2009. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 19 

Appendix A 

SUMMARY OF PROPOSED AMENDMENTS 

Rule 101 – General Provisions and Definitions 

EXISTING 

SECTION 

NEW 

SECTION 

CHANGE 

204.45 Same Added common name, HFE-7100, for this compound. 

204.47 Same Added common name, HFE-7200, for this compound. 

New 204.50 Added HFE-7000 to the list of exempt compounds. 

New 204.51 Added HFE-7500 to the list of exempt compounds. 

New 204.52 Added methyl formate to the list of exempt compounds 

New 204.53 Added HFE-7300 to the list of exempt compounds. 

New 204.54 Added propylene carbonate to the list of exempt compounds. 

New 204.55 Added dimethyl carbonate to the list of exempt compounds 

204.50 204.56 Section renumbered. 

 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 20 

APPENDIX B 

HEALTH RISK ASSESSMENT 

Point Source Modeling Parameters 

Emission Rate: 1 gram per second 

Release Type: Default 

Stack Height: 20 feet 

Stack Temperature: 140° Fahrenheit 

Exit Diameter: 2.83 feet 

Exit Velocity: 31.8 feet per second 

Flow Rate: 12,000 cubic feet per minute 

Building Height: 14 feet 

Land: Urban 

Point Source BEEST for Windows Output 

Max Annual Concentration: 95.09 (ug/m3)/(g/s) 

Max 1-hour Concentration: 1,081.5 (ug/m3

)/(g/s) 

Volume Source Modeling Parameters 

Emission Rate: 1 gram per second 

Building Dimensions: 24 feet x 24 feet x 12 feet (length x width x height) 

Release Height: 10 feet 

Horizontal Dim: 5.58 feet (length/4.3) 

Vertical Dim: 5.58 feet (height/2.15) 

Elevation: 0 feet 

Land: Urban 

Volume Source BEEST for Windows Output 

Max Annual Concentration: 1,878 (ug/m3

)/(g/s) 

Max 1-hour Concentration: 21,708 (ug/m3

)/(g/s) 

Hazard Index 

Hazard Index = Concentration (ug/m3

)/(g/s) * Emission Rate (g/s) 

Reference Exposure Level (ug/m3

) 

Cancer Risk 

Cancer Risk = Inhalation Unit Risk Factor (ug/m3

)

-1 * Concentration (ug/m3

)/(g/s)) * Emission Rate (g/s) 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 21 

Methyl Formate 

Density: 8.17 lb/gal 

Acute Reference Exposure Level (REL): 11,400 ug/m3

Calculating the maximum emission rate (ER) from a point source to have an acute hazard index (HI) of 1: 

ER = (HI * REL)/1-hour Conc. 

ER = (1 * 11,400 ug/m3

)/( 1,081.5 (ug/m3)/(g/s)) 

ER = 10.5 g/s 

Hourly Emission = ER * 0.0022 lb/g * 3600 s/hr 

Hourly Emission = 10.5 g/s * 0.0022 lb/g * 3600 s/hr 

Hourly Emission = 83.6 lb/hr 

Calculating the maximum emission rate from a volume source to have an acute HI of 1: 

ER = (HI * REL)/1-hour Conc. 

ER = (1 * 11,400 ug/m3

)/( 21,708 (ug/m3)/(g/s)) 

ER = 0.53 g/s 

Hourly Emission = ER * 0.0022 lb/g * 3600 s/hr 

Hourly Emission = 0.53 g/s * 0.0022 lb/g * 3600 s/hr 

Hourly Emission = 4.16 lb/hr 

 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 22 

Dimethyl Carbonate 

Density: 8.92 lb/gal

Acute Reference Exposure Level (REL): 18,000 ug/m3

Chronic Reference Exposure Level (REL): 5,500 ug/m3

Calculating the maximum emission rate from a point source to have an acute HI of 1: 

ER = (HI * Acute REL)/1-hour Conc. 

ER = (1 * 18,000 ug/m3

)/( 1,081.5 (ug/m3)/(g/s)) 

ER = 16.6 g/s 

Hourly Emission = ER * 0.0022 lb/g * 3600 s/hr 

Hourly Emission = 16.6 g/s * 0.0022 lb/g * 3600 s/hr 

Hourly Emission = 132 lb/hr 

Calculating the maximum emission rate from a volume source to have an acute HI of 1: 

ER = (HI * Acute REL)/1-hour Conc. 

ER = (1 * 18,000 ug/m3

)/( 21,708 (ug/m3)/(g/s)) 

ER = 0.83 g/s 

Hourly Emission = ER * 0.0022 lb/g * 3600 s/hr 

Hourly Emission = 0.83 g/s * 0.0022 lb/g * 3600 s/hr 

Hourly Emission = 6.58 lb/hr 

Calculating the maximum emission rate from a point source to have a chronic HI of 1: 

ER = (HI * Chronic REL)/Annual Conc. 

ER = (1 * 5,500 ug/m3

)/( 95.09 (ug/m3)/(g/s)) 

ER = 57.8 g/s 

Annual Emission = ER * 0.0022 lb/g * 3600 s/hr * 8hr/day * 5 days/wk * 52 wk/yr 

Annual Emission = 57.8 g/s * 0.0022 lb/g * 3600 s/hr * 8hr/day * 5 days/wk * 52 wk/yr 

Annual Emission = 954,000 lb/year 

Calculating the maximum emission rate from a volume source to have a chronic HI of 1: 

ER = (HI * Chronic REL)/Annual Conc. 

ER = (1 * 5,500 ug/m3

)/( 1,878 (ug/m3)/(g/s)) 

ER = 2.93 g/s 

Annual Emission = ER * 0.0022 lb/g * 3600 s/hr * 8hr/day * 5 days/wk * 52 wk/yr 

Annual Emission = 2.93 g/s * 0.0022 lb/g * 3600 s/hr * 8 hr/day * 5 days/wk * 52 wk/yr 

Annual Emission = 48,300 lb/year 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 23 

Tertiary Butyl Acetate 

Density of TBAc: 7.18 lb/gal 

Inhalation Unit Risk Factor (URF) = 4 x 10-7 (ug/m3

)

-1

Calculating the maximum emission from a point source to have a cancer risk of less than 10 in a million: 

 ER = Cancer Risk/(URF*Annual Conc) 

 ER = (10 x10-6)/(4 x 10-7 (ug/m3

)

-1 * 95.09 (ug/m3

)/(g/s)) 

 ER = 0.26 g/s 

Annual TBAc Emission = ER * 0.0022 lb/g * 3600 s/hr * 8 hr/day * 5 days/wk * 52 wk/yr 

Annual TBAc Emission = 0.26 g/s * 0.0022 lb/g * 3600 s/hr * 8 hr/day * 5 days/wk * 52 wk/yr 

Annual TBAc Emission = 4340 lb/year 

 Assume: 80% of VOC is replaced by TBAc 

 Annual VOC Emission = 4340 lb/year / 80% 

 Annual VOC Emission = 5425 lb/year 

Calculating the maximum emission from a volume source to have a cancer risk of less than 10 in a 

million: 

 ER = Cancer Risk/(URF*Annual Conc) 

 ER = (10 x10-6)/(4 x 10-7 (ug/m3

)

-1 * 1,878 (ug/m3

)/(g/s)) 

 ER = 0.01 g/s 

Annual TBAc Emission = ER * 0.0022 lb/g * 3600 s/hr * 8 hr/day * 5 days/wk * 52 wk/yr 

Annual TBAc Emission = 0.01 g/s * 0.0022 lb/g * 3600 s/hr * 8 hr/day * 5 days/wk * 52 wk/yr 

Annual TBAc Emission = 220 lb/year 

Assume: 80% of VOC is replaced by TBAc 

Annual VOC Emission = 220 lb/year / 80% 

Annual VOC Emission = 275 lb/year 

Calculating the District permitting threshold: 

Permitting threshold = 1 gallon of coatings and solvents per day 

Permitting threshold = 1 gallon/day * 5 days/wk * 52 wk/yr 

Permitting threshold = 260 gallons/yr 

Calculating the average VOC content to emit VOC emissions that exceed the cancer risk 

Average VOC content = Annual VOC Emissions/Permitting threshold 

Average VOC content = 275 lb/yr / 260 gallons/yr 

Average VOC content = 1.1 lb/gallon 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 24 

APPENDIX C 

COMMENTS AND RESPONSES 

Public Workshop for Rules 101, 451 and 459 

September 16, 2010, 2:00 PM 

Attendees: 

Allen Cripe, CalTrans Josh Cox, Jerry’s Paint 

Brad Gacke, SMUD June Livingston, BERC 

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

Brittany Marcotte, Nestle Waters North 

America Kendall McCane, Jerry’s Paint 

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

Cerlut Fre, Sherwin-Williams Kevin Thompson, Thompson Sales 

Clifford Waters, Sherwin-Williams Larry Medrano, PBE Inc 

Dale Schell, Jim’s Color Corner Lisa Dobeck, Caltrans 

Dan Porreau, LyondellBasell Mark McCleskey, Jerry’s Paint 

Danny Nunez, Finish Masters Mark Tavianini, CARB 

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

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

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

David McClune, California Autobody 

Association Pat Stickle, Angel Warehouse 

David Roznowski, LyondellBasell Peter Bezech, California Autobody Association 

Debra Wynne, Original Paint Phil Brown, PPG Industries 

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

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

Eric Cooc, Precision Autobody Robert Blair, Finish Mater 

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

Glenn Galbaugh, DuPont Company Stan Brecetu, 3M 

Grey Calhorn, Finish Master Steve Nesbitt, PCL 

Jason Kowen, Spies Hecker Terry Klemin, Matrix 

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

Jeremy Tiner, Warehouse Paint Tom Walther, Jim’s Color Corner 

Jim Brett, CalTrans 

Vern Heffner, City of Sacramento Fleet 

Management 

Jim Cropper, CARB 

Oral Comments from the Public Workshop 

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

Rule 459. Only comments pertaining to the proposed amendments to Rule 101 are shown 

below. 

Comment #1 Lyondell supports the exemption of propylene carbonate in Rule 101. 

Response: Thank you for your comment. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 25 

Comment #2 Lyondell objects to the unequal treatment of TBAc with regard to dimethyl 

carbonate and methyl formate. Lyondell requests that the proposed 

amendments exempt TBAc with the same restriction as for dimethyl 

carbonate and methyl formate. 

Response: Staff is no longer proposing to add permitting restrictions to dimethyl 

carbonate and methyl formate because Staff has determined from health 

risk modeling that these compounds will not cause an adverse impact on 

human health. Staff has not changed its position on TBAc and is not 

proposing to exempt TBAc in Rule 101. Because TBAc is a potential 

carcinogen and may be used in a variety of applications, the decision to 

exempt TBAc would need to be looked at within each prohibitory rule. 

Most recently, Staff reviewed the potential impacts of exempting TBAc as 

a VOC in Rule 459, Automotive, Mobile Equipment, and Associated Parts 

and Components Coating Operations, and provided a limited exemption 

for TBAc. 

Written Comments from Environmental Protection Agency dated 9/3/2010 

Comment #3 Office of Air Quality Planning and Standards (OAQPS) plans to fix an 

editorial error in 40 CFR 51.100. The name of the compound should be 

1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-trifluoromethyl-pentane (HFE7300), instead of (1) 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-

trifluoromethyl-pentane (HFE-7300). The “(1)” should be removed. 

Response: Staff has made the change in the proposed amendments to Rule 101. 

Written Comments from LyondellBasell dated 8/31/2010 

Comment #4 We support the addition of propylene carbonate to the list of exempt 

compounds. 

Response: Thank you for your comment. 

Comment #5 The staff report for Rule 101 cites CARB’s 2006 environmental impact 

assessment as the reason for not proposing the exemption of TBAc. 

CARB’s concern at the time was that TBAc could pose a potential cancer 

risk to humans because TBAc metabolized to TBA. Since CARB’s 2006 

Environmental Impact Assessment on TBAc, several studies have 

confirmed that neither TBA nor TBAc are genotoxic, potential human 

carcinogens, or reproductive toxins. 

Response: Staff relied on the published toxicity evaluations from experts at OEHHA 

and CARB. Staff contacted OEHHA regarding the studies mentioned in 

the comment letter. According to OEHHA staff, these studies have not 

provided sufficient evidence demonstrating that the rodent tumor studies 

are not relevant to humans. Therefore, OEHHA still considers TBAc to be 

a potential human carcinogen. Staff will reconsider an exemption for 

TBAc when OEHHA or CARB has concluded that it will not cause an 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 26 

adverse impact to human health. 

 Meanwhile, Staff will consider an exemption for TBAc within specific 

prohibitory rules as they are adopted or amended. Staff will review the 

potential impacts and determine whether exempting TBAc would cause 

an adverse impact to human health. 

Comment #6 DMC metabolizes to methanol, a chemical OEHHA has proposed to add 

to Prop 65 as a reproductive toxin, which in turn metabolizes to 

formaldehyde, a probable human carcinogen. Therefore, it is 

incongruous that staff would propose the exemption of dimethyl 

carbonate in Rule 101 but not TBAc, whose metabolite TBA is neither a 

listed carcinogen nor reproductive toxin. 

Response: The Prop 65 list is a notification requirement regarding the use of 

compounds that are considered to be carcinogens or reproductive toxins. 

Methanol is proposed to be added to the Prop 65 list as a reproductive 

toxin; however, no action has been taken by OEHHA. Furthermore, 

OEHHA has concluded in a memo to CARB18 that there is no evidence of 

carcinogenicity for methanol, the primary metabolite of dimethyl 

carbonate, despite a robust database on toxicity and a long history of 

human exposure. Also, according to OEHHA, formaldehyde, the 

metabolite for methanol, is carcinogenic by inhalation, but in the case of 

dimethyl carbonate exposure, formaldehyde would be formed inside the 

human body. This formation has not shown that the internal levels of 

dissolved or bound formaldehyde produced by intermediary metabolism 

or by methanol oxidation are associated with cancer. OEHHA further 

concluded that the proposed interim acute and chronic REL are expected 

to be protective of anticipated adverse health effects, including the 

developmental toxicity observed in the key study reported for dimethyl 

carbonate. Therefore, Staff expects that an exemption for dimethyl 

carbonate will not cause adverse impact on human health. 

Comment #7 We believe that adding TBAc to Rule 101 with the same use restrictions 

(permit requirements) as dimethyl carbonate and methyl formate is 

consistent with the science, rulemakings in several other California 

counties and air districts, protective of human health, and provides the 

District with a mechanism to review potential risks on a case-by-case 

basis. We request that TBAc be added to the list of exempt compounds in 

Rule 101 with the same permitting requirements as dimethyl carbonate 

and methyl formate. 

Response: See responses to comments #2 and #5. 

 

 

18 “Revised Assessment of Health Effects of Exposure to Dimethyl Carbonate, A Chemical Petitioned for 

Exemption from VOC Rules,” Memorandum from OEHHA to Air Resources Board, December 8, 2009. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 27 

Written Comments from LyondellBasell in E-mail dated 9/1/2010 

Comment #8 We object to the uneven handling of TBAc compared to dimethyl 

carbonate and methyl formate and request that TBAc also be added to 

the list of exempts in Rule 101 with the same permitting requirements. 

Response: See response to comment #2. 

Written Comments from Miami Chemicals dated 9/8/2010 

Comment #9 Miami Chemical supports the proposed amendments to Rule 101. 

Response: Thank you for your comment. 

Written Comments from Kowa American Corporation dated 9/9/2010 

Comment #10 Kowa American Corp would like to ask the SMAQMD to exempt the 

solvent dimethyl carbonate as a VOC. We feel dimethyl carbonate being 

VOC exempt will allow your local businesses a much greater degree of 

flexibility in meeting the more stringent VOC restrictions moving forward. 

Response: Staff is proposing to exempt dimethyl carbonate from the District’s 

definition of VOC in Rule 101. 

Comment #11 We understand the District is contemplating having users of dimethyl 

carbonate apply for permits to use dimethyl carbonate. We think this 

would add an unnecessary amount of extra work for your air district. 

Response: Staff has performed a health risk assessment and has determined that 

dimethyl carbonate will not cause an adverse impact on human health; 

therefore, Staff is no longer proposing to add permitting requirements for 

dimethyl carbonate. 

Comment #12 If a permit is required, we would ask that: a sunset provision be included 

for the permit requirement, increase the permit to a larger amount (say for 

usages of more than 1,000 gallons per year) and allow contractors to use 

their permit across the air district instead of requiring one for each 

individual work site. We think these suggestions would make a permit 

process much easier for dimethyl carbonate users and for your District’s 

employees. 

Response: See response to comment #11. 

Written Comments from American Coating Association (ACA) dated 9/9/2010 

Comment #13 ACA supports the comments by Lyondellbasell and Kowa and suggests 

that propylene carbonate, TBAc, and dimethyl carbonate all be added to 

the list of exempt compounds without any restrictions since these 

compounds were exempted by the U.S. EPA, nearly every state in the 

U.S., and many California air districts based on their negligible 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 28 

contribution to tropospheric ozone formation. 

Response: See responses to Comments #2, #4 through #8, and #10 through #12. 

Staff is proposing to add propylene carbonate and dimethyl carbonate to 

the list of exempt compounds in Rule 101. At this time, Staff is not 

proposing to exempt TBAc as a VOC because of its potential adverse 

impact on human health. Instead, Staff intends to review the impacts of 

TBAc on a rule-by-rule basis and where Staff determines it appropriate, 

include an exemption or limited exemption for TBAc. 

Comment #14 If the District does not outright exempt TBAc, ACA suggests to be fair the 

District should exempt TBAc and include the same permit requirements 

as dimethyl carbonate and methyl formate in order to address any 

possible concerns with the use of TBAc. 

Response: See response to Comment #2. 

Written Comments from AkzoNobel Car Refinishes dated 9/16/2010 

Comment #15 TBAc has been fully exempted as a VOC by the U.S. EPA and in the 

following California Air Pollution Control Districts: San Joaquin, Santa 

Barbara, Yolo-Solano APCD. 

Response: U.S. EPA exempted TBAc as a VOC for the purpose of meeting VOC 

content limits or VOC emission limits, but EPA maintained its status as a 

VOC for the purposes of recordkeeping, emissions reporting, 

photochemical modeling, and emissions inventory requirements. At this 

time, Staff is not proposing to exempt TBAc in Rule 101 because of the 

potential adverse impact to human health but will assess the 

appropriateness of exempting it under specific rules. See response to 

Comment #5. 

Comment #16 AkzoNobel suggests that the exemption for TBAc should be moved from 

Rule 459, Section 268, to Rule 101, Section 204, in order to clarify that 

the TBAc is VOC exempt and would eliminate the need for any further 

tracking use. 

Response: See response to Comment #15. Regardless of where an exemption for 

TBAc would be allowed, District rules would include recordkeeping and 

tracking as required by the U.S. EPA exemption. 

Written Comments from DuPont Performance Coatings dated 9/17/2010 

Comment #17 We struggle to understand the conditional exemption of dimethyl 

carbonate and methyl formate. Like many of the other solvents exempted 

from consideration as a VOC, dimethyl carbonate and methyl formate 

would be incorporated into finished products. End-users may not have 

the capacity to track this required information, and we believe the 

provision is unnecessarily burdensome. 
Staff Report 

Rule 101 – General Provisions and Definitions 

September 23, 2011 

Page 29 

Response: See response to Comment #2. Staff is no longer proposing permitting 

requirements for dimethyl carbonate and methyl formate. 

Comment #18 We struggle to understand the absence of an exemption for TBAc. 

Manufacturers need every tool to formulate coatings that meet everlowering VOC standards. TBAc is VOC-exempt in most States and some 

California Air Districts. This solvent is effective for a wide range of 

coatings types, and formulations for surface preparation. There is a 

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

for use in the industry. 

Response: Staff understands that TBAc may be used in a wide range of applications. 

As such, there is a potential for a significant increase in the use of TBAc 

within the District if it is exempted as a VOC. According to the information 

from CARB’s Environmental Impact Assessment of Tertiary-Butyl 

Acetate, TBAc is a potential human carcinogen, and its increased use 

may potentially cause an adverse impact on human health. Staff intends 

to review the impacts of TBAc on a rule-by-rule basis and determine if 

there is a need to exempt TBAc and if the potential use of TBAc in 

specific applications will not cause adverse impacts on human health. 

Comment #19 Because of their broad usefulness in formulation and demonstrated 

safety, we request that the District fully exempt all solvents currently 

exempted by U.S. EPA. 

Response: Staff is not proposing the add TBAc and HFC-227ea to the list of exempt 

compounds because of the potential adverse impact to human health or 

the environment. Compounds exempted from the federal VOC definition 

are not automatically exempted from District rules and regulations. The 

District considers a number of factors, including potential uses, impact on 

human health, and environmental concerns before adding federallyexempt compounds to Rule 101.