The California Department of Pesticide Regulation (DPR) recently released the post-harvest commodity fumigation component of a multipart independent scientific study evaluating alternatives to fumigant pesticides. Photo courtesy of DPR

SACRAMENTO REGION, CA (MPG) – The California Department of Pesticide Regulation (DPR) recently released the post-harvest commodity fumigation component of a multipart independent scientific study evaluating alternatives to fumigant pesticides.

Prepared by the California Council on Science and Technology (CCST), the convening report summarizes key themes and discussion points from a convening assembled by CCST to discuss fumigants that are used to protect stored food products after harvest, potential alternatives and opportunities to reduce exposure for workers and nearby communities.

CCST’s convening included academic, industry, public health, environmental justice and regulatory experts who met for a series of discussions on post-harvest commodity fumigation in November 2025. The discussion specifically focused on four fumigant pesticides: methyl bromide, sulfuryl fluoride, phosphine and propylene oxide. All four fumigants are restricted material pesticides primarily used on produce after harvesting to protect food from fungal disease and insect pests while in storage. The report synthesizes findings from those discussions to summarize and reflect participants’ diverse perspectives on the state of post-harvest commodity fumigation in California.

The convening report includes discussion summaries related to:

How and why post‑harvest fumigants are used today, including factors that drive fumigation for stored commodities.

Community exposure and emission concerns, along with current mitigation practices and opportunities to strengthen protections for nearby residents and workers.

Available and emerging alternatives to traditional fumigants, such as controlled atmospheres, irradiation, pheromone‑based tools, and multi‑pronged Integrated Pest Management approaches.

Barriers that limit the adoption of alternatives, including international and national regulatory requirements, cost, and the need for additional research and training.

Key research gaps where further scientific study is needed to support a transition to safer, effective pest management tools.

Background

Funded by the Budget Act of 2023, DPR commissioned an independent study following the release of the Sustainable Pest Management (SPM) Roadmap to look at fumigant use in the state; existing alternatives to fumigants; past and ongoing research dedicated to fumigant alternatives; the viability of adopting these alternatives to effectively manage pests in California and barriers to, and incentives for, wide-scale adoption of alternatives. 

CCST’s first report focused on the soil fumigants 1,3-D and chloropicrin, and DPR published its findings in May 2025. The second report from CCST evaluated alternatives to sulfuryl fluoride, with its findings published in February 2026.

The CCST study is part of multiple efforts led by DPR to advance its mission to foster SPM in California with a vision for safe, effective and sustainable pest management for all Californians and the environment.

The final part of the study will focus on the pre-plant fumigants methyl bromide, dazomet, metam-sodium and metam-potassium and is anticipated to conclude this year.