2024 Final 1,3-D Annual Report Now Available

The California Department of Pesticide Regulation (DPR) has released the final 2024 1,3-dichloropropene (1,3-D) Annual Report. 1,3-D is a fumigant pesticide injected into the soil before planting to control a wide spectrum of pests.

This report is the first issued under the non-occupational bystander regulation adopted in 2024, which established new requirements intended to reduce 1,3 D air concentrations, including updated fumigation methods, limits on application rates and acreage, higher soil moisture standards, and setback distances from occupied structures. The regulation requires DPR produce an annual evaluation of 1,3 D use and air monitoring data from the prior calendar year, including a review of concentrations in the townships with the highest 1,3-D use. It also directs DPR to model air concentrations when they exceed regulatory thresholds to assess whether mitigation requirements are working as intended and to determine whether additional measures are needed.

The final report includes revisions made in response to public comments following: