2025 was another active year in California regarding the ongoing evaluation of exposure data and potential future regulatory actions affecting the use of sulfuryl fluoride-based fumigants. Fumigant registrants worked closely with the pest control industry, the building and rental property industries, production agriculture, specialty crop advocates, food processors, and other allies to advocate for policies that would allow continued access to this uniquely versatile and effective fumigant.
Fumigant Alternatives Research
In late 2023, as part of an ongoing effort to implement its Sustainable Pest Management (SPM) Initiative, the California Department of Pesticide Regulation (CDPR) contracted with the California Council on Science and Technology (CCST)1 to conduct an evaluation of potential alternatives to nine fumigants used in three applications. The scope of work included sulfuryl fluoride (SF) used in both structural and post-harvest commodity fumigation. Use of SF in structural fumigation was identified as the second priority following completion of research on 1,3-Dichloropropene (1,3-D) and Chloropicrin.2 The contract keeps DPR at arms-length from the research process to avoid any concerns about agency influence biasing the process or the results.
Based on concern about the narrow focus of the research and the insular nature of the CCST process, the structural fumigation and agriculture industries collaborated on an advocacy campaign to open CCST's process to external input. Two separate coalition letters were submitted to CDPR calling for more real-world expertise and a more fulsome analysis that compares theoretical alternatives to SF across the range of factors that inform its use, including efficacy, market availability, and cost-effectiveness. Following some initial resistance, both CDPR and CCST solicited nominations from the public for the core SF research teams and for external technical advisors, and some of the nominees were selected to help balance the academic perspectives. The structural fumigation report was completed by mid-year, but to date has not been released to the public.
For post-harvest commodity fumigation, CCST ultimately concluded that it lacked sufficient information on potential alternatives to support a scientific investigation, and decided instead to convene a group of subject matter experts to explore a range of issues including policy, pest, and trade drivers, assess existing and emerging alternatives, identify barriers to broader adoption of alternatives, identify data gaps necessitating additional research, and assess the availability and efficacy of emission reduction measures. CCST
______________________________________
1 CCST is a state funded organization established by the California Legislature to advise state government bodies on science and technology policy issues.
2 CDPR issued a press release announcing completion of this phase of the fumigant alternatives research project on March 13, 2025, concluding that none of the individual fumigant alternatives would qualify as drop-in replacements for the subject fumigants because "each offers unique benefits and is constrained by unique limitations" (see: https://www.cdpr.ca.gov/2025/03/13/dpr-releases-first-phase-of-state-funded-fumigant-alternatives-study-focused-on-13-d-and-chloropicri
ultimately selected a 10-member panel composed primarily of industry experts representing fumigant registrants, pest control operators, and commodity advocates. The post-harvest convening was held in November 2025 and CCSTwill prepare a report synthesizing the input from panel members for further consideration by CDPR.
The structural fumigation study report and the proceedings from the post-harvest convening will be considered by DPR in determining the need for additional mitigation measures for SF in both applications.
Exposure Monitoring StudyIn Spring 2025, CDPR informed Douglas Products and members of the California Pest Management Association (CAPMA) about the results of a post-structural fumigation monitoring study it conducted in late 2024 through early 2025. At the request of Douglas and Cardinal Professional Products, CDPR shared the study protocol, which affirmed industry concerns that the study lacked sufficient technical rigor. In particular, the CDPR protocol did not employ standards typically required by the US Environmental Protection Agency (US EPA) or by CDPR for human exposure monitoring. Douglas and Cardinal representatives engaged with CDPR management and the research team to address the deficiencies in the study protocol. As a first step, industry representatives worked with CDPR to develop additional best management practices (BMPs) that homeowners can implement before and after fumigation. After extensive discussions and multiple iterations, the parties agreed to a final version which has since been published by Douglas and distributed by CAPMA.
Douglas also informed CDPR that it intended to conduct additional post-fumigation exposure monitoring studies in several homes in California using standard federal and state protocols and different label-required doses of SF. Douglas drafted the study protocol in consultation with CAPMA members and has submitted it to CDPR for review. Douglas specifically requested that CDPR's Human Health Assessment Branch Exposure Assessment Unit review the protocol in addition to Worker Health and Safety Branch, which conducted the initial study. Douglas also proposed a meeting with CDPR to discuss the draft protocol before conducting the study, which is expected to run from Spring through Summer 2026. It appears as of the date of this article that CDPR intends to collaborate with Douglas and CAPMA on this new study, which they now reference as "Phase 2" of their ongoing exposure monitoring research. Douglas and CAPMA are currently awaiting DPR's review of the draft study protocol.
Biannual Legislative UpdatePursuant to California Food and Agriculture Code Section 14024, CDPR is required to either adopt measures to mitigate potential residential and bystander exposures to SF during structural fumigations or submit a report to the Legislature at least once every two years explaining why it has not adopted such measures. CDPR's last report was due before the
end of 2023 but was submitted to the Legislature in March 2024. Since CDPR has no pending SF-related regulatory proposals, CDPR is expected to submit another update to the Legislature, which is technically due before the end of 2025, but as with the prior report, is not likely to be completed until the first quarter of 2026. Based on CDPR's current activities related to SF, it is likely that the next report will focus on ongoing research, including CCST's evaluation of potential alternatives to SF in structural fumigation, which was identified as a priority in the 2023 report, and the forthcoming "Phase 2" exposure monitoring study, as additional information that will inform any future regulatory actions on SF.
Potential Legislative ThreatsIn Fall 2022, two environmental non-governmental organizations (ENGO), the Center for Biological Diversity and Californians for Pesticide Reform, filed a petition with the California Air Resources Board (CARB) asserting that CARB has a duty to regulate SF as a greenhouse gas (GHG) based on its global warming potential (GWP). In Winter 2023, following a period of review and stakeholder engagement, including extensive discussions with SF registrants and user groups, CARB denied the petition and deferred further evaluation and regulation of SF to CDPR.3 However, CARB's decision did not resolve the question of whether SF should be regulated as a GHG, and ENGOs continue to explore other mechanisms to advance the agenda reflected in the 2022 Petition.
Most recently, it has come to the attention of industry representatives that another ENGO, Climate Action California (CAC), is shopping concepts for a legislative proposal in 2026. In August 2025, CAC released a White Paper advocating for new restrictions on the use of SF based on an analysis that overstates SF's impact on climate change and misrepresents the availability, practical feasibility, and commercial viability of new emissions control technology and alternative treatment methods. Specifically, CAC recommends adding SF to the list of state-regulated GHGs, and enacting a "feebate," wherein rebates are provided to companies that use SF controls, heat treatments in lieu of structural fumigation, or other unspecified alternatives, using revenues obtained from new fees on SF-based
fumigants. The White Paper indicates that CAC was shopping these concepts in state legislative offices as of late Summer 2025, and since that time has approached both CARB and CDPR to gauge their interest.
Given this activity and the many misrepresentations in the CAC White Paper, there is a need to correct the record with potential bill authors and other legislators before they make any commitments to CAC or other ENGOs seeking authors or support for their legislative proposals. This process is already underway in anticipation of the legislature reconvening
______________________________________
3 California Air Resources Board, Response to Petition to Regulate Sulfuryl Fluoride to Reduce the Use of the High Global Warming Potential Pesticide, February 24, 2023 (see:
https://ww2.arb.ca.gov/sites/default/files/2023-02/Pesticide%20Petition%20Response approved02242023.pdf).
in January 2026 for the second year of the current two year session, and is being coordinated by fumigant registrants, CAPMA and the agriculture industry.
Based on your engagement on SF regulatory issues in the past or pesticide issues generally, we believe you may be interested in collaborating on early outreach to potentially receptive legislators to provide important facts and context regarding the importance of SF, the minimal impact it has on global climate change, and the lack of viable alternatives or treatment technologies.
Prioritization of Pesticides for EvaluationIn early 2025, CDPR announced that it is developing a public, data-driven process to inform CDPR's approach to prioritizing pesticides for further evaluation. As part of this process, CDPR intends to establish a 15-member scientific advisory committee to provide science-based recommendations to CDPR on potential priority actions, including risk assessments, data requirements, mitigation development, and product cancellation.
CDPR proposed that committee members would collectively have expertise in numerous subject matter areas that included some technical scientific disciplines, such as chemistry and toxicology, and subject matter areas that did not clearly require scientific expertise, such as traditional ecological knowledge.
In written comments to CDPR, industry representatives urged CDPR to ensure the scientific advisory committee members included a balance of perspectives, including the perspectives of the pest control industry and industries that rely on pesticides to protect California's homes, businesses, food supply, and economy. The commenters also recommended that CDPR seek committee members with subject matter expertise that is more clearly relevant to the scientific disciplines that inform CDPR's regulatory work, including toxicology, ecotoxicology, biology, entomology, epidemiology, health risk assessment, and chemical fate and transport. Industry representatives also emphasized that committee meetings and deliberations must be transparent, be open to the public, and consider stakeholder input.
In response to public input, in October 2025, CDPR provided additional detail regarding the purpose, required qualifications, and processes of the scientific advisory committee, which it has named the "Scientific Prioritization and Review Committee" (SPARC), and began soliciting nominations for the SPARC. It specified the experts it seeking to serve on the SPARC include an agricultural practitioner with experience in crop management and pest management and an urban practitioner with experience in urban pest management and urban pesticide use. However, the SPARC membership overall will still have a heavy environmental and ecological focus.
As CDPR finalizes and begins to implement its pesticide prioritization process, continued industry engagement will be critical to ensure that the SPARC's recommendations to CDPR are based on a complete record, including relevant scientific information provided by
product registrants and pest control operators. Industry attention and engagement will also be useful to avoid the risk that the SPARC may unnecessarily devote resources to evaluating pesticides that CDPR is already actively evaluating, whether formally or informally, and pesticides that CDPR has recently evaluated in the absence of significant new scientific data supporting SPARC review.
SPM Advisory Committee
In November 2025, CDPR began accepting applications for a 3-year position on the Sustainable Pest Management (SPM) Advisory Committee to support CDPR's mission to foster SPM statewide. CDPR formed the SPM Advisory Committee in response to a recommendation in the Sustainable Pest Management Roadmap for California, which was developed and released by a cross-sector workgroup in January 2023 to provide recommendations to the state for a systemwide transition to more sustainable pest management. The Committee's role is to provide an avenue for public discussion and input to inform CDPR actions related to SPM, including tracking progress and implementation of SPM statewide, developing SPM pilot projects, advancing procurement and supply chain opportunities, reviewing urban pesticide use data, identifying and implementing continuing education opportunities, and promoting, developing, and adopting innovative pest management alternatives.
The SMP Advisory Committee may include up to 15 people with experience in environmental science, agricultural urban and natural space Integrated Pest Management (1PM), pesticide alternatives, consumer food certification, corporate social responsibility, food supply chains, public health, and community advocacy, to serve on the SPM Advisory Committee. Several product registrants and pest control operators have submitted applications for committee membership, with support from CAPMA and other business and industry trade groups.
Building Relationships
In 2025, the leadership team at CDPR underwent significant changes, including the appointment of a new Director, Dr. Karen Morrison, in February 2025, and the appointment of a new Chief Deputy Director, Leia Bailey, in April 2025. In addition, several key program Deputy Directors were newly appointed in the past few years, including Dr. Jennifer (JT) Teerlink, who became the Deputy Director over the Pesticide Program Division's Pesticide Registration, Pesticide Evaluation, and Human Health Assessment branches in 2023, Dr. Sapna Thottathil, who became the Deputy Director for Sustainable Pest Management in 2024, and Madison Le, who became the Deputy Director for Monitoring and Mitigation in 2025.
Throughout 2025, product registrants, pest control operators, and business and industry groups have proactively worked to establish new collaborative relationships and to build on existing relationships with CDPR's leadership. Business and industry coalitions have engaged with CDPR through regular meetings, including meetings with individual stakeholders to discuss specific issues and recurring meetings of stakeholder groups, and through formal public comment opportunities. The regular dialogue and positive interactions between industry representatives and CDPR leadership and key staff result have successfully resulted in increased transparency and opportunities for meaningful industry input, and increased understanding of industry concerns, including related to CDPR's oversight of the CCST study of fumigant alternatives, the role of pesticides within the framework of SPM, and proposed pesticide prioritization process and the role of the SPARC. Maintaining and further developing the positive relationships built in 2025 will be critical to continued successes in 2026.
Fumigant Alternatives Research
In late 2023, as part of an ongoing effort to implement its Sustainable Pest Management (SPM) Initiative, the California Department of Pesticide Regulation (CDPR) contracted with the California Council on Science and Technology (CCST)1 to conduct an evaluation of potential alternatives to nine fumigants used in three applications. The scope of work included sulfuryl fluoride (SF) used in both structural and post-harvest commodity fumigation. Use of SF in structural fumigation was identified as the second priority following completion of research on 1,3-Dichloropropene (1,3-D) and Chloropicrin.2 The contract keeps DPR at arms-length from the research process to avoid any concerns about agency influence biasing the process or the results.
Based on concern about the narrow focus of the research and the insular nature of the CCST process, the structural fumigation and agriculture industries collaborated on an advocacy campaign to open CCST's process to external input. Two separate coalition letters were submitted to CDPR calling for more real-world expertise and a more fulsome analysis that compares theoretical alternatives to SF across the range of factors that inform its use, including efficacy, market availability, and cost-effectiveness. Following some initial resistance, both CDPR and CCST solicited nominations from the public for the core SF research teams and for external technical advisors, and some of the nominees were selected to help balance the academic perspectives. The structural fumigation report was completed by mid-year, but to date has not been released to the public.
For post-harvest commodity fumigation, CCST ultimately concluded that it lacked sufficient information on potential alternatives to support a scientific investigation, and decided instead to convene a group of subject matter experts to explore a range of issues including policy, pest, and trade drivers, assess existing and emerging alternatives, identify barriers to broader adoption of alternatives, identify data gaps necessitating additional research, and assess the availability and efficacy of emission reduction measures. CCST
______________________________________
1 CCST is a state funded organization established by the California Legislature to advise state government bodies on science and technology policy issues.
2 CDPR issued a press release announcing completion of this phase of the fumigant alternatives research project on March 13, 2025, concluding that none of the individual fumigant alternatives would qualify as drop-in replacements for the subject fumigants because "each offers unique benefits and is constrained by unique limitations" (see: https://www.cdpr.ca.gov/2025/03/13/dpr-releases-first-phase-of-state-funded-fumigant-alternatives-study-focused-on-13-d-and-chloropicri
ultimately selected a 10-member panel composed primarily of industry experts representing fumigant registrants, pest control operators, and commodity advocates. The post-harvest convening was held in November 2025 and CCSTwill prepare a report synthesizing the input from panel members for further consideration by CDPR.
The structural fumigation study report and the proceedings from the post-harvest convening will be considered by DPR in determining the need for additional mitigation measures for SF in both applications.
Exposure Monitoring StudyIn Spring 2025, CDPR informed Douglas Products and members of the California Pest Management Association (CAPMA) about the results of a post-structural fumigation monitoring study it conducted in late 2024 through early 2025. At the request of Douglas and Cardinal Professional Products, CDPR shared the study protocol, which affirmed industry concerns that the study lacked sufficient technical rigor. In particular, the CDPR protocol did not employ standards typically required by the US Environmental Protection Agency (US EPA) or by CDPR for human exposure monitoring. Douglas and Cardinal representatives engaged with CDPR management and the research team to address the deficiencies in the study protocol. As a first step, industry representatives worked with CDPR to develop additional best management practices (BMPs) that homeowners can implement before and after fumigation. After extensive discussions and multiple iterations, the parties agreed to a final version which has since been published by Douglas and distributed by CAPMA.
Douglas also informed CDPR that it intended to conduct additional post-fumigation exposure monitoring studies in several homes in California using standard federal and state protocols and different label-required doses of SF. Douglas drafted the study protocol in consultation with CAPMA members and has submitted it to CDPR for review. Douglas specifically requested that CDPR's Human Health Assessment Branch Exposure Assessment Unit review the protocol in addition to Worker Health and Safety Branch, which conducted the initial study. Douglas also proposed a meeting with CDPR to discuss the draft protocol before conducting the study, which is expected to run from Spring through Summer 2026. It appears as of the date of this article that CDPR intends to collaborate with Douglas and CAPMA on this new study, which they now reference as "Phase 2" of their ongoing exposure monitoring research. Douglas and CAPMA are currently awaiting DPR's review of the draft study protocol.
Biannual Legislative UpdatePursuant to California Food and Agriculture Code Section 14024, CDPR is required to either adopt measures to mitigate potential residential and bystander exposures to SF during structural fumigations or submit a report to the Legislature at least once every two years explaining why it has not adopted such measures. CDPR's last report was due before the
end of 2023 but was submitted to the Legislature in March 2024. Since CDPR has no pending SF-related regulatory proposals, CDPR is expected to submit another update to the Legislature, which is technically due before the end of 2025, but as with the prior report, is not likely to be completed until the first quarter of 2026. Based on CDPR's current activities related to SF, it is likely that the next report will focus on ongoing research, including CCST's evaluation of potential alternatives to SF in structural fumigation, which was identified as a priority in the 2023 report, and the forthcoming "Phase 2" exposure monitoring study, as additional information that will inform any future regulatory actions on SF.
Potential Legislative ThreatsIn Fall 2022, two environmental non-governmental organizations (ENGO), the Center for Biological Diversity and Californians for Pesticide Reform, filed a petition with the California Air Resources Board (CARB) asserting that CARB has a duty to regulate SF as a greenhouse gas (GHG) based on its global warming potential (GWP). In Winter 2023, following a period of review and stakeholder engagement, including extensive discussions with SF registrants and user groups, CARB denied the petition and deferred further evaluation and regulation of SF to CDPR.3 However, CARB's decision did not resolve the question of whether SF should be regulated as a GHG, and ENGOs continue to explore other mechanisms to advance the agenda reflected in the 2022 Petition.
Most recently, it has come to the attention of industry representatives that another ENGO, Climate Action California (CAC), is shopping concepts for a legislative proposal in 2026. In August 2025, CAC released a White Paper advocating for new restrictions on the use of SF based on an analysis that overstates SF's impact on climate change and misrepresents the availability, practical feasibility, and commercial viability of new emissions control technology and alternative treatment methods. Specifically, CAC recommends adding SF to the list of state-regulated GHGs, and enacting a "feebate," wherein rebates are provided to companies that use SF controls, heat treatments in lieu of structural fumigation, or other unspecified alternatives, using revenues obtained from new fees on SF-based
fumigants. The White Paper indicates that CAC was shopping these concepts in state legislative offices as of late Summer 2025, and since that time has approached both CARB and CDPR to gauge their interest.
Given this activity and the many misrepresentations in the CAC White Paper, there is a need to correct the record with potential bill authors and other legislators before they make any commitments to CAC or other ENGOs seeking authors or support for their legislative proposals. This process is already underway in anticipation of the legislature reconvening
______________________________________
3 California Air Resources Board, Response to Petition to Regulate Sulfuryl Fluoride to Reduce the Use of the High Global Warming Potential Pesticide, February 24, 2023 (see:
https://ww2.arb.ca.gov/sites/default/files/2023-02/Pesticide%20Petition%20Response approved02242023.pdf).
in January 2026 for the second year of the current two year session, and is being coordinated by fumigant registrants, CAPMA and the agriculture industry.
Based on your engagement on SF regulatory issues in the past or pesticide issues generally, we believe you may be interested in collaborating on early outreach to potentially receptive legislators to provide important facts and context regarding the importance of SF, the minimal impact it has on global climate change, and the lack of viable alternatives or treatment technologies.
Prioritization of Pesticides for EvaluationIn early 2025, CDPR announced that it is developing a public, data-driven process to inform CDPR's approach to prioritizing pesticides for further evaluation. As part of this process, CDPR intends to establish a 15-member scientific advisory committee to provide science-based recommendations to CDPR on potential priority actions, including risk assessments, data requirements, mitigation development, and product cancellation.
CDPR proposed that committee members would collectively have expertise in numerous subject matter areas that included some technical scientific disciplines, such as chemistry and toxicology, and subject matter areas that did not clearly require scientific expertise, such as traditional ecological knowledge.
In written comments to CDPR, industry representatives urged CDPR to ensure the scientific advisory committee members included a balance of perspectives, including the perspectives of the pest control industry and industries that rely on pesticides to protect California's homes, businesses, food supply, and economy. The commenters also recommended that CDPR seek committee members with subject matter expertise that is more clearly relevant to the scientific disciplines that inform CDPR's regulatory work, including toxicology, ecotoxicology, biology, entomology, epidemiology, health risk assessment, and chemical fate and transport. Industry representatives also emphasized that committee meetings and deliberations must be transparent, be open to the public, and consider stakeholder input.
In response to public input, in October 2025, CDPR provided additional detail regarding the purpose, required qualifications, and processes of the scientific advisory committee, which it has named the "Scientific Prioritization and Review Committee" (SPARC), and began soliciting nominations for the SPARC. It specified the experts it seeking to serve on the SPARC include an agricultural practitioner with experience in crop management and pest management and an urban practitioner with experience in urban pest management and urban pesticide use. However, the SPARC membership overall will still have a heavy environmental and ecological focus.
As CDPR finalizes and begins to implement its pesticide prioritization process, continued industry engagement will be critical to ensure that the SPARC's recommendations to CDPR are based on a complete record, including relevant scientific information provided by
product registrants and pest control operators. Industry attention and engagement will also be useful to avoid the risk that the SPARC may unnecessarily devote resources to evaluating pesticides that CDPR is already actively evaluating, whether formally or informally, and pesticides that CDPR has recently evaluated in the absence of significant new scientific data supporting SPARC review.
SPM Advisory Committee
In November 2025, CDPR began accepting applications for a 3-year position on the Sustainable Pest Management (SPM) Advisory Committee to support CDPR's mission to foster SPM statewide. CDPR formed the SPM Advisory Committee in response to a recommendation in the Sustainable Pest Management Roadmap for California, which was developed and released by a cross-sector workgroup in January 2023 to provide recommendations to the state for a systemwide transition to more sustainable pest management. The Committee's role is to provide an avenue for public discussion and input to inform CDPR actions related to SPM, including tracking progress and implementation of SPM statewide, developing SPM pilot projects, advancing procurement and supply chain opportunities, reviewing urban pesticide use data, identifying and implementing continuing education opportunities, and promoting, developing, and adopting innovative pest management alternatives.
The SMP Advisory Committee may include up to 15 people with experience in environmental science, agricultural urban and natural space Integrated Pest Management (1PM), pesticide alternatives, consumer food certification, corporate social responsibility, food supply chains, public health, and community advocacy, to serve on the SPM Advisory Committee. Several product registrants and pest control operators have submitted applications for committee membership, with support from CAPMA and other business and industry trade groups.
Building Relationships
In 2025, the leadership team at CDPR underwent significant changes, including the appointment of a new Director, Dr. Karen Morrison, in February 2025, and the appointment of a new Chief Deputy Director, Leia Bailey, in April 2025. In addition, several key program Deputy Directors were newly appointed in the past few years, including Dr. Jennifer (JT) Teerlink, who became the Deputy Director over the Pesticide Program Division's Pesticide Registration, Pesticide Evaluation, and Human Health Assessment branches in 2023, Dr. Sapna Thottathil, who became the Deputy Director for Sustainable Pest Management in 2024, and Madison Le, who became the Deputy Director for Monitoring and Mitigation in 2025.
Throughout 2025, product registrants, pest control operators, and business and industry groups have proactively worked to establish new collaborative relationships and to build on existing relationships with CDPR's leadership. Business and industry coalitions have engaged with CDPR through regular meetings, including meetings with individual stakeholders to discuss specific issues and recurring meetings of stakeholder groups, and through formal public comment opportunities. The regular dialogue and positive interactions between industry representatives and CDPR leadership and key staff result have successfully resulted in increased transparency and opportunities for meaningful industry input, and increased understanding of industry concerns, including related to CDPR's oversight of the CCST study of fumigant alternatives, the role of pesticides within the framework of SPM, and proposed pesticide prioritization process and the role of the SPARC. Maintaining and further developing the positive relationships built in 2025 will be critical to continued successes in 2026.