DPR 22-005 Health Risk Mitigation and Volatile Organic Compound Emission Reduction for 1,3-Dichloropropene

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DPR 22-005 Health Risk Mitigation and Volatile Organic Compound Emission Reduction for 1,3-Dichloropropene (Notice 11/18/22; Comment period closes 1/18/23; "15-day" comment period 5/9/23-5/31/23; Second "15-day" comment period 7/25/23-8/10/23)

DPR adopted sections 6448.1, 6448.3 and 6448.4 and amended sections 6448, 6448.1 (renumbered to 6448.2), 6449.1, 6452, 6452.2, 6624, 6626, and 6881 of Title 3, California Code of Regulations. This action restricts the use of 1,3-dichloropropene (1,3-D) to mitigate the potential 72-hour acute risk and 70-year lifetime cancer risk to non-occupational bystanders. The mitigation measures also further reduce the emissions of 1,3-D as a volatile organic compound. This action allows the use of 1,3-D only for the production of agricultural commodities, effectively prohibiting other uses that are not currently registered; establishes mandatory setbacks (distances from occupied structures where 1,3-D cannot be applied); sets limits on the application rate and acres treated for individual field soil fumigations; places restrictions on multiple field soil fumigations that do not meet distance or time separation criteria; limits the allowed methods to apply 1,3-D, including establishing criteria for acceptable types of tarpaulins that can be used; requires an annual report from DPR that includes evaluations of 1,3-D use and air monitoring results; and requires the inclusion of certain information in existing pesticide use records and pesticide use reports. DPR also incorporated “1,3-Dichloropropene Field Fumigation Requirements, Est. January 1, 2024” by reference in sections 6448, 6448.2, 6624, and 6626. A copy of this document is posted below.

A public hearing was held on January 18, 2023, in a hybrid format to receive oral or written comments regarding the proposed action. A public hearing was also held on May 31, 2023, in a hybrid format to receive oral or written comments regarding the proposed modifications that were available for public comment from May 9, 2023 to May 31, 2023.

• Notice of Proposed Regulatory Action, PDF (En Español, PDF)
• Proposed Text, PDF
  • 1,3-Dichloropropene Field Fumigation Requirements, Est. January 1, 2024, PDF
• Initial Statement of Reasons, PDF
• Economic and Fiscal Impact Statement (Form 399), PDF
• Notice of Modifications to Text, PDF (En Español, PDF) "15-day" comment period 5/9/23-5/31/23
• Text of Modified Regulations, PDF
  • 1,3-Dichloropropene Field Fumigation Requirements, Est. January 1, 2024, PDF
  • 1,3-Dichloropropene Field Fumigation Requirements, Est. January 1, 2024 – Clean copy; NOT FOR COMMENT, PDF
• Notice of Addition of Documents to Rulemaking File, PDF "15-day" comment period 5/9/23-5/31/23
  • Brown, Colin. 2023. "Modeling broadcast-strip TIF applications with 40% tarp coverage," Department of Pesticide Regulation Report, April 3, 2023.
  • Goodhue, R., K. Mace, S. Blecker, Y. Zheng, S. Raburn, J. Rudder, A. Spalding, T. Tolhurst, H. Wei, B. Gress, and J. Steggall. 2023. "Addendum to the June 2022 Economic and Pest Management Evaluation of Proposed 1,3-Dichloropropene Regulation," University of California, Davis and California Department of Food and Agriculture Report, March 13, 2023.
  • Luo, Yuzhou. 2023. "Addendum: Modeling for mitigation measures to reduce acute exposure from 1,3-Dichloropropene, Revised setback tables," Department of Pesticide Regulation Report, April 3, 2023.
  • Luo, Yuzhou. 2023a. "Addendum: Modeling for mitigation measures to reduce acute exposure from 1,3-Dichloropropene, Applications with a minimum soil moisture of 25% of field capacity," Department of Pesticide Regulation Report, April 3, 2023.
  • Luo, Yuzhou and R. Uyeda. 2023. "Modeling the high detections of 1,3-Dichloropropene in DPR’s Air Monitoring Network," Department of Pesticide Regulation Report, April 3, 2023.
  • Mace, Kevi. 2023. "Number of Farms Using 1,3-Dichloropropene - updated," California Department of Food and Agriculture memorandum, April 4, 2023.
• Notice of Second Modifications to Text, PDF (En Español, PDF) "15-day" comment period 7/25/23-8/10/23
• Text of Second Modified Regulations, PDF
• Final Statement of Reasons, PDF
  • Attachment A, PDF
  • Attachment B, PDF
  • Attachment C, PDF
• Final Text of Regulations, PDF Filed with Secretary of State 12/22/23; Effective 1/1/24
  • 1,3-Dichloropropene Field Fumigation Requirements, Est. January 1, 2024, PDF
• Documents Relied Upon
  1. Brajkovich, Laurie. 2022. "APCAC Meeting Update and 1,3-D Proposed Regs," Department of Pesticide Regulation email, August 16, 2022.
  2. Brown, Colin. 2019. "HYDRUS-simulated flux estimates of 1,3-dichloropropene maximum period-averaged flux and emission ratio for approved application methods," Department of Pesticide Regulation Report, October 17, 2019.
  3. Brown, Colin. 2022. "Updates to HYDRUS-simulated flux estimates of 1,3-dichloropropene maximum period-averaged flux and emission ratios," Department of Pesticide Regulation Report, September 22, 2022., PDF
  • 4A. DPR. 2016a. "Response to comments by OEHHA on DPR-HHAB’s draft 1,3-dichloropropene risk assessment document (dated August 31, 2015)." August 6, 2016. Department of Pesticide Regulation.
  • 4B. DPR. 2016b. "Response to comments by US EPA on DPR-HHAB’s draft 1,3-Dichloropropene Risk Characterization Document dated August 31, 2015." September 8, 2016. Department of Pesticide Regulation.
  • 4C. DPR. 2016c. "Responses to comments by Dr. Urmila P. Kodavanti on DPR-HHAB’s draft 1,3- Dichloropropene Risk Characterization Document dated Aug. 31, 2015." September 8, 2016. Department of Pesticide Regulation.
  • 4D. DPR. 2016d. "Responses to comments by Dr. Richard A. Fenske on DPR-HHAB’s draft 1,3- Dichloropropene Risk Characterization Document dated November 19, 2015." September 8, 2016. Department of Pesticide Regulation.
  • 4E. DPR. 2016e. "Responses to comments by Dr. Weisueh A. Chiu on DPR-HHAB’s draft 1,3- Dichloropropene Risk Characterization Document dated August 31, 2015." September 14, 2016. Department of Pesticide Regulation.
  • 4F. DPR. 2016f. "Response to comments by Dow AgroSciences on DPR-HHAB’s draft 1,3- Dichloropropene Risk Characterization Document dated Aug. 31, 2015." November 8, 2016. Department of Pesticide Regulation.
  5. DPR. 2015b. "1,3-Dichloropropene Risk Characterization Document: Inhalation Exposure to Workers, Occupational and Residential Bystanders and the General Public." December 31, 2015. Department of Pesticide Regulation.
  6. DPR. 2019. "Responses to the External Peer Review of the Methodology to Develop a Township Cap for 1,3-Dichloropropene." May 2019. Department of Pesticide Regulation.
  7. DPR. 2021. "Comments on the September 28, 2021 Draft Risk Management Directive for 1,3-Dichloropropene and Responses." October 2021. Department of Pesticide Regulation.
  8. DPR. 2022a. "Review by the Toxic Air Contaminant Workgroup of Documents Related to the Draft 1,3-Dichloropropene Regulations," Department of Pesticide Regulation document, November 7, 2022., PDF
  9. DPR. 2022b. "Agricultural Pesticide Control Advisory Committee Agenda, December 14, 2022." Department of Pesticide Regulation.
  10. DPR. 2022c. "Overview of Draft 1,3-D Regulations," Department of Pesticide Regulation email, August 15, 2022.
  11. DPR. 2022d. "Pesticide Registration and Evaluation Committee Agenda, November 18, 2022." Department of Pesticide Regulation.
  12. Edwards, David. 2022. "OEHHA’s Response to DPR’s Request for Agreement Regarding DPR’s Development of a Regulation to Mitigate Risks to Non-Occupational Bystanders from 1,3-D Use," Office of Environmental Hazard Assessment memorandum, September 20, 2022.
  13. Goodhue, R., K. Mace, S. Blecker, Y. Zheng, J. Rudder, A. Spalding, T. Tolhurst, H. Wei, B. Gress, and J. Steggall. 2022a. Economic and pest management evaluation of proposed 1,3-Dichloropropene. University of California, Davis and California Department of Food and Agriculture Report, June 21, 2022.
  14. Goodhue, R., K. Mace, S. Blecker, Y. Zheng, J. Rudder, A. Spalding, T. Tolhurst, H. Wei, B. Gress, and J. Steggall. 2022b. Addendum to the June 2022 economic and pest management evaluation of proposed 1,3-Dichloropropene regulation. University of California, Davis and California Department of Food and Agriculture Report, June 23, 2022.
  15. Henderson, Julie. 2021. "Risk Management Directive and Mitigation Guidance for Acute, Non-Occupational Bystander Exposure from 1,3-Dichloropropene (1,3-D)," Department of Pesticide Regulation Memorandum, October 19, 2021.
  16. Kandelous, Maziar. 2019. "A comparison between field-estimated and HYDRUS-simulated emission of 1,3-Dichloropropene from agricultural fields," Department of Pesticide Regulation Report, October 17, 2019.
  17. Kandelous, Maziar. 2022. "Developing mitigation measures for 1,3-dichloropropene applications: An overview of the Pilot Studies." Department of Pesticide Regulation Report, October 11, 2022., PDF
  18. Luo, Yuzhou. 2019a. "Evaluating AERMOD for simulating ambient concentrations of 1,3-dichloropropene," Department of Pesticide Regulation Report, October 17, 2019.
  19. Luo, Yuzhou. 2019b. "AERFUM: an integrated air dispersion modeling system for soil fumigants," Department of Pesticide Regulation Report, October 17, 2019.
  20. Luo, Yuzhou. 2022a. "Modeling for mitigation measures to reduce acute exposure from 1,3-Dichloropropene, modeling approach #2," Department of Pesticide Regulation Report, September 12, 2022., PDF
  21. Luo, Yuzhou. 2022b. "Modeling for mitigation measures to reduce acute exposure from 1,3-Dichloropropene, modeling approach #1," Department of Pesticide Regulation Report, September 12, 2022., PDF
  22. Luo, Yuzhou. 2022c. "Modeling for the township cap of 1,3-Dichloropropene applications, modeling approach #2," Department of Pesticide Regulation Report, September 12, 2022., PDF
  23. Luo, Yuzhou and Colin Brown. 2022. "Modeling for application factors of 1,3-Dichloropropene, modeling approach #2," Department of Pesticide Regulation Report, September 12, 2022.
  24. Mace, Kevi. 2022. "Number of Farms Using 1,3-Dichloropropene," California Department of Food and Agriculture memorandum, August 4, 2022.
  25. Marks, Teresa. 2016a. "Comments on the Draft Risk Management Directive for 1,3-Dichloropropene (1,3-D) and Responses." Department of Pesticide Regulation Letter, October 6, 2016.
  26. Marks, Teresa. 2016b. "Risk Management Directive and Mitigation Guidance for Cancer Risk from 1,3-Dichloropropene (1,3-D)," Department of Pesticide Regulation Memorandum, October 6, 2016.
  27. Morrison, Karen. 2022. "Request for OEHHA Agreement Regarding DPR’s Development of a Regulation to Mitigate Risks to Non-Occupational Bystanders from 1,3-D Use," Department of Pesticide Regulation letter, September 16, 2022.
  28. Rubin, Daniel. 2022. "Analysis of the applicability of Food and Agricultural Code sections 12980 and 12981 to proposed 1,3-dichloropropene regulations addressing acute and cancer risk to non-occupational bystanders," Department of Pesticide Regulation memorandum, October 17, 2022.
  29. Segawa, Randy and Yuzhou Luo. 2022. "Analysis of the Sufficiency of Acute Mitigation Measures to Mitigate Cancer Risk from 1,3-Dichloropropene," Department of Pesticide Regulation Memorandum, November 3, 2022., PDF
  30. Tuli, Atac, Colin Brown and Yvan Delgado. 2022. "Guideline to determine soil water content (moisture) at field capacity," Department of Pesticide Regulation Report, September 20, 2022., PDF
  31. Tuli, Atac and Delgado, Yvan. 2022. "Analysis of high barrier tarpaulin cis-1,3-Dichloropropene mass transfer coefficient data measured under high relative humidity conditions," Department of Pesticide Regulation Memorandum, September 20, 2022., PDF
  32. USDA. 1998. "Estimating Soil Moisture by Feel and Appearance." U.S. Department of Agriculture, Natural Resources Conservation Service, Program Aid Number 1619, April 1998.