I ii i (I'd Slides limimnmenlal Pro loci ion .\»enc\ Office of Research ;iikI l)o\ olopmoiil National Kxposure Research Laboratory Research Abstract Government Performance Results Act (GPRA) Goal # 1 Annual Performance Measure #131 Significant Research Findings: Report on the Scientific Basis of a New, Updated Reactivity Policy Scientific The U.S. Congress, in response to industry concerns, conducted Reactivity Problem and Hearings in 1998 on implementation of Section 183(e) of the 1990 Clean Air Act, Policy Issues which requires the U.S. EPA Administrator to develop a reactivity-based strategy for control of hydrocarbon emissions from consumer and commercial products. Based on these hearings, Congress instructed EPA to provide the credible scientific information needed for implementing Section 183(e). Responding to Congressional concerns, EPA commenced an effort to review and update its reactivity policy, and established a partnership-type collaboration with external groups. The Reactivity Research Working Group (RRWG), consisting of representatives from federal and state government agencies, private industry, environmental groups, and universities, was founded in 1998 (at EPA's initiative) to identify issues and associated research needs, and to sponsor research in the reactivity area. The driving force behind the interest in volatile organic hydrocarbon (VOC) reactivity is the fact that different VOCs in the atmosphere can produce vastly different amounts of ozone and particulate matter (PM). Thus, efforts to control ambient concentrations of ozone and PM might be more efficient and cost- effective if they first focus on high producers, rather than decreasing emissions of all VOCs equally. EPA's Office of Research and Development (ORD) has participated in the RRWG and in the development of research plans, and used this information to support EPA's Office of Air Quality Planning and Standards (OAQPS) in their development of guidance and policy for applying VOC reactivity-based controls as a component of State Implementation Plans (SIPs). Research The general objective of this work has been to participate in the development of Approach scientific information needed to identify and evaluate an accurate, efficient, and cost-effective control strategy for anthropogenic VOCs based on their individual reactivities for ozone and PM formation. This effort was performed in cooperation and coordination with the RRWG. ORD's contribution to this effort has focused on three areas: 1. the provision of financial and technical support to build a new-generation ------- smog chamber facility for studies of atmospheric chemistry and reactivity of VOCs under low NOx conditions; 2. participation in the RRWG meetings and workshops, particularly in the development and implementation of a research program to help address these scientific issues identified by the RRWG; and 3. providing technical support and consultation to OAQPS on reactivity- related issues. The emphasis of the work performed by ORD under all three areas is the development of robust, scientifically justifiable, quantifications of the potential ozone formation caused by a wide variety of anthropogenic VOC emissions. These values are being used to study the feasibility of regional and national control strategies based on this VOC-specific potential for ozone formation, and eventually to consider PM formation. Results and The RRWG has been working since 1998, enjoying continued support from its Impact government, industry and academic partners. The RRWG has sponsored workshops and generated technical papers, model simulations, reports, and experimental studies to help answer technical questions related to reactivity. Major technical findings of the work to date include: Atmospheric chemistry mechanisms were tested under controlled, realistic conditions and found to perform well. This result implies that previous modeling of atmospheric chemistry is valid and useful. Substituting low reactivity compounds for higher reactivity compounds, on a greater than 1:1 ratio can decrease ozone concentrations, depending on the compound and the substitution ratio. A number of scientifically valid ways to describe reactivity can be defined. It is possible to describe a reactivity scale which could be applied across the entire United States, depending on the objective. These findings were presented by ORD to the NARSTO Executive Assembly on April 12, 2005. ORD has used the information developed by the RRWG to provide the scientific basis for review of two policies developed by OAQPS. One of them is a pilot project in California which substitutes mass-based VOC limits with reactivity- based limits for aerosol coatings. The second is an advanced notice of rulemaking on use of reactivity nationwide, and included consideration of other effects such as toxicity and PM formation potential. The research performed by the RRWG and EPA/ORD helps provide the scientific understanding, evidence, and tools needed by EPA and the states to evaluate the feasibility of using a reactivity-based control strategy for VOCs, as part of their SIPs demonstrating compliance with National Ambient Air Quality Standards (NAAQS). The research directly addresses issues associated with implementation of Section 183(e) of the 1990 Clean Air Act, and it responds to Congressional directives. It contributes toward ORD's Long-Term Goal of producing advanced and accurate tools that can be used by the Agency to support the implementation ------- of current ozone standards and to improve the science used in reviewing these standards. All research in this area has been conducted in close collaboration with the RRWG. Assistance for the Community Multiscale Air Quality (CMAQ) simulations was provided under contract #68-W-01-032 with Computer Sciences Corporation. The research effort also benefitted from interactions with OAQPS. A recent presentation associated with this work is: Luecken, D.J., 2005. "Report on status of scientific research performed by the Reactivity Research Working Group," presented at the NARSTO Executive Assembly, in Las Vegas, NV, April 11-12, 2005. EPA clearance NERL-RTP-AMD-05-025. Regulatory actions that this effort has contributed to include: "Revisions to the California State Implementation Plan and Revision to the Definition of Volatile Organic Compounds (VOC) - Removal of VOC Exemptions for California's Aerosol Coating Products Reactivity-based Regulation." Federal Register, Vol. 70, No. 176, Sept. 13,2005. (Published with concurrence without comment by ORD.) "Interim Guidance on Control of Volatile Organic Compounds in Ozone State Implementation Plans." Federal Register, Vol. 70, No. 176, Sept. 13, 2005. (No concurrence by ORD, contributions to section III.) Future Research The support for reactivity-based control strategies expressed in the "Interim Guidance on Control of Volatile Organic Compounds in Ozone State Implementation Plans" raises many questions about "real life" applications of reactivity, including how States will quantify reactivity values. Research done by the RRWG has demonstrated several approaches, and calculated reactivities for lumped model species and a few explicit VOC species. But the research has not addressed the issue of calculations for the hundreds of VOC species that are used in consumer and commercial products. The RRWG has demonstrated that reactivity scales can vary substantially, depending on the method chosen, and has begun to attempt standardization of these calculations, but much work still remains to be done. Future research must focus on the derivation of standardized reactivity values that are scientifically robust and acceptable to regulators. Additional studies must be done to establish potential disbenefits of any reactivity policy, such as increases in the overall global background concentrations of low-reactivity VOCs. Understanding and accounting for overall uncertainty in the estimates of reactivity, especially for compounds that are not well studied and have high uncertainty, remains to be an important task. Questions and inquiries can be directed to: Deborah J. Luecken U.S. EPA, Office of Research and Development National Exposure Research Laboratory Atmospheric Modeling Division, E243-03 Research Triangle Park, North Carolina 27711 Phone: 919/541-0244 E-mail: luecken.deborah@epa.gov Research Collaboration and Research Products Contacts for Additional Information ------- Funding for this project was through the U.S. EPA's Office of Research and Development, National Exposure Research Laboratory, and the work was conducted by the Atmospheric Modeling Division. ------- |