Rule 1020 (Definitions) February 21, 2013
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SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT Final Draft Staff Report: Rule 1020 (Definitions) February 21, 2013 SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT FINAL DRAFT STAFF REPORT Proposed Amendments to Rule 1020 (Definitions) February 21, 2013 Prepared by: Lisa Van de Water, Air Quality Specialist Reviewed by: Brian Clerico, Air Quality Engineer Glenn Reed, Senior Air Quality Specialist Anna Myers, Senior Air Quality Specialist Leland Villalvazo, Supervising Air Quality Specialist Jessi Fierro, Supervising Air Quality Specialist Mike Oldershaw, Manager, Compliance Errol Villegas, Program Manager, Strategies and Incentives Samir Sheikh, Director, Strategies and Incentives I. SUMMARY Rule 1020 (Definitions) defines terms used throughout other San Joaquin Valley Air Pollution Control District (District) rules, including a list of compounds exempt from ozone regulations due to their low ozone forming potential. The District occasionally amends District Rule 1020 to update these definitions as they are revised by the Environmental Protection Agency (EPA). The District proposes to make several updates related to the list of exempt compounds, including adding several additional compounds and clarifying requirements for several existing compounds. The first proposed rule amendment is to add dimethyl carbonate (DMC) and propylene carbonate (PC) to the District’s list of exempt compounds within the definition of volatile organic compounds (VOC) (Section 3.53) as a response to EPA findings that DMC and PC have a low potential to form ozone in the atmosphere. EPA found that these compounds are less photo-chemically reactive than ethane and, thus, have a negligible contribution to ozone formation. EPA announced the exemption of DMC and PC in the Federal Register, effective February 2009 (included as Appendix B). By exempting these compounds, manufacturers of coatings or solvent cleaning materials have additional options with which to formulate low-VOC coatings and cleaning materials. The District also proposes to remove unnecessary permitting requirements for two previously exempted compounds: methyl formate (MF) and tertiary-butyl acetate 1 Final Draft Staff Report with Appendices for Proposed Amendments to Rule 1020 SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT Final Draft Staff Report: Rule 1020 (Definitions) February 21, 2013 (TBAc). Based on the District’s analysis, the District determined that the current permit requirements included in Rule 1020 for MF and TBAc are not needed and will subsequently be removed. The District evaluated the potential health impacts associated with these proposed amendments and concluded that they would not cause adverse health impacts. The District’s analysis was based on worst-case assumptions, including assuming that the use of the proposed exempt compounds would be entirely new, when, in fact, their use would be in lieu of other chemical compounds that could often pose a greater risk. While these compounds are exempt from VOC regulations under Rule 1020, the District’s permitting process evaluates the potential health risk from all new and modified operations to ensure that they do not cause significant health impacts to San Joaquin Valley (Valley) residents. II. RULE DEVELOPMENT PROCESS As part of the rule development process, the District posted draft amendments to Rule 1020 and solicited comments from the public, stakeholders, the California Air Resources Board (ARB), and EPA over a 30-day period just prior to hosting a public workshop on December 29, 2010. The District postponed further action on the proposed amendments to Rule 1020 based on a request by ARB to allow them an opportunity to further review the issue on a statewide basis. ARB ultimately did not publish such a review, and the District proceeded with evaluating and preparing the proposed amendments to Rule 1020, consistent with EPA’ 2009 ruling. The District will publish and make available the proposed amendments to Rule 1020 to stakeholders for review prior to a public hearing of the Governing Board to consider adoption of the proposed rule amendments. The District will evaluate comments received and incorporate them as appropriate. The proposed amendments are scheduled to be presented to the Governing Board during a public hearing on February 21, 2013. III. BACKGROUND Not all organic compounds have equal potential to form ozone in the atmosphere. EPA has revised the federal definition of VOCs several times to exclude organic compounds from the definition of VOCs based on their negligible contribution to ozone formation. By adding a compound to the list of exempt compounds, EPA is encouraging its use as a replacement for other chemicals that are significantly more likely to contribute to ozone formation. Effective February 2009, EPA added DMC and PC to the federal exempt compounds list on the basis that these compounds are less photo-chemically reactive than ethane and, thus, have negligible contribution to ozone formation. The 2 Final Draft Staff Report with Appendices for Proposed Amendments to Rule 1020 SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT Final Draft Staff Report: Rule 1020 (Definitions) February 21, 2013 EPA announced the delisting of these chemicals in the Federal Register, which is attached as Appendix B. If a chemical can be replaced by one with a lower potential to form ozone, the amount of ozone formed in the atmosphere will be reduced. Because both DMC and PC appear to be likely candidates to replace VOCs in a number of high-use products, the District proposes amendments to Rule 1020 (Definitions) to add DMC and PC to the District’s list of exempt VOCs. Previous District actions similarly amended Rule 1020 to exempt tertiary-butyl acetate (TBAc) and methyl formate (MF) as a result of EPA actions exempting such compounds. The previous District actions set a limit for use of TBAc and MF at one gallon per year per facility; use above that threshold currently requires the operator to get a Permit to Operate (PTO). During the evaluation and risk assessment for the current action (exemption of DMC and PC), District staff determined that the one-gallon threshold for TBAc and MF is redundant and unnecessary given the Risk Management Review required by District Rules 2201 (New and Modified Stationary Source Review) and 2020 (Exemptions) for all compounds with potential risk, especially cumulative risk of compounds that, by themselves, are below the District’s significance threshold. Therefore, the proposed amendments to Rule 1020 (Definitions) include deletion of the TBAc and MF use limitations to reduce redundancy and improve clarity. IV. DISCUSSION The District received a request from Kowa American Corporation (Kowa) to amend Rule 1020 (Definitions) to include DMC and PC as exempt VOCs, as defined in Section 3.53 in the rule. In July 2004, Kowa petitioned the federal government to exempt DMC as a VOC. EPA approved the exemption of DMC and PC as VOCs in 2009 (see Appendix B) after several years of evaluation of the ozone-reducing values and environmental, toxicity, and safety profiles of these compounds. Section 3.53 of Rule 1020 defines VOCs and lists compounds that are both organic and volatile, yet are considered by the District to have a low potential to form ozone, thus making them exempt from regulatory requirements. One of the proposed amendments to Rule 1020 changes the definition of VOC in Section 3.53 to add DMC and PC to the list of exempt compounds. By exempting DMC and PC, manufacturers of coatings or solvent cleaning materials have additional compounds with which to formulate low-VOC coatings and cleaning materials. Dimethyl Carbonate (DMC) DMC is a colorless, fast-evaporating solvent with a substantial polar nature, i.e. it is water soluble. Manufacturers and suppliers of DMC expect it to be an effective 3 Final Draft Staff Report with Appendices for Proposed Amendments to Rule 1020 SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT Final Draft Staff Report: Rule 1020 (Definitions) February 21, 2013 replacement for esters, glycol ethers, and ketones in formulations. For some cleaning applications, DMC may be used to replace isopropyl alcohol, although DMC is less polar than isopropyl alcohol and therefore may not work as efficiently as isopropyl alcohol. In addition, DMC has solubility and other properties that might make it a replacement for trichloroethylene in solvent cleaning operations. The flash point (the lowest temperature at which a liquid can vaporize to form an ignitable mixture in air) of DMC is higher than some solvents already in wide-spread use like acetone, ethyl acetate, and methyl ethyl ketone (MEK), thus making DMC an attractive replacement in applications that use these solvents. It also has the potential to replace isopropyl alcohol and trichloroethylene in cleaning and solvent applications. By contrast, the flammability of DMC may limit its use in consumer coatings, indoor application coatings, and as a hand-wipe cleaning solvent. DMC may also replace some compounds such as xylene, toluene, MEK and hexane, which have been identified as toxic air contaminants by the ARB. Based on the following information and the risk assessment detailed below, the exemption of DMC as a VOC is not expected to pose a significant health risk to Valley residents if substituted for a non-exempt VOC at District-regulated stationary sources. Given that the most likely application of DMC is as a replacement in coatings or as a cleaning solvent, inhalation is expected to be the primary pathway of human exposure due to evaporation of the solvent. This exposure would be similar to any other paint, sealant and adhesive solvent that DMC would be intended to replace. There may also be some minor skin exposure from coatings splattering or careless mixing operations. Oral exposure would be rare and is limited to accidental ingestion. Data from Kowa American, the manufacturer of this chemical, indicates that once DMC enters the body, it can be converted into methanol and carbon dioxide.