EPA Announces Early Mitigation for Sulfuryl Fluoride Used to Fumigate Homes

Released on June 30, 2023

The U.S. Environmental Protection Agency (EPA) is announcing the Agency’s final early mitigation decision for the structural fumigant sulfuryl fluoride. The “Sulfuryl Fluoride Revised Mitigation and Response to Comments on the Draft Interim Re-entry Mitigation Measures Memorandum” addresses the EPA Office of the Inspector General’s (OIG) report findings that EPA can better prevent deaths and serious injuries caused during residential fumigations by amending sulfuryl fluoride labels and monitoring compliance.

Sulfuryl fluoride is a fumigant used to control pests such as termites, powder post beetles, old house borers, bedbugs, carpet beetles, moths, cockroaches, rats, and mice. It is a restricted-use pesticide, meaning it can only be used by a certified applicator or someone under the certified applicator’s direct supervision. To use sulfuryl fluoride, a residential structure is covered with a tent to contain the gas, then it is filled with sulfuryl fluoride gas to kill pests. Once the fumigation is complete, the structure is aired out and the inside air is tested using a “clearance device” to ensure that the amount of sulfuryl fluoride is at or below the “clearance level”, determined by the Agency as a safe level for humans to re-enter.

The OIG Report was based on human health incidents that occurred after a home had been “cleared” for re-entry. The OIG Report detailed corrective actions for EPA implementation, which are addressed in this early mitigation decision. The early mitigation proposal was open for a 120-day comment period, from May 25, 2021, until September 23, 2021. After considering public comments and meeting with stakeholders, the EPA has finalized the early mitigation for the residential uses of sulfuryl fluoride with enhanced safety guidelines. Based on EPA testing results indicating that some of the clearance devices currently listed on sulfuryl fluoride labels do not accurately measure the clearance level, the Agency has determined the following mitigation measures are necessary to provide protections for people returning to their homes after a fumigation with sulfuryl fluoride. The structural fumigant mitigation measures to be implemented will:

1. Require clearly posted no-entry warning signs to prevent admittance to fumigation tents throughout the fumigation process; 
2. Require site-specific fumigation logs for residential fumigations; 
3. Require additional registrant sponsored application stewardship training;  
4. Remove references to “approved” clearance devices from product labels and refer users to the EPA website, which will list the portable clearance devices determined to be effective, according to the EPA’s performance criteria; and 
5. Require longer active and passive aeration times for residential structural fumigations.  

To implement this mitigation, the Agency is requiring the revised language be included on all sulfuryl fluoride labels with residential structural uses to be submitted to the Agency for review by August 30, 2023. Once the revised labels are stamped, the existing label stock can be used in the market for a maximum of 12 months.

The final early mitigation and response to comments on the draft early mitigation proposal can now be found in the mitigation and response document, available in the public docket (EPA-HQ-OPP-2009-0136) at regulations.gov.

While these mitigation measures are focused only on residential structural fumigations, sulfuryl fluoride and all of its registered uses are still undergoing registration review, a process that re-evaluates all pesticides on a 15-year cycle. The remaining registration review risk assessments for sulfuryl fluoride are anticipated to be completed and issued for public comment in 2024.

Further information on sulfuryl fluoride can be found on EPA’s website.