The U.S. Environmental Protection Agency (EPA) announced on August 21, 2025, the availability of and solicited public comment on materials that are being submitted to the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Scientific Advisory Panel (SAP) for peer review on “Determining the Absence of Novel Proteins in the Saliva of Genetically Engineered [(GE)] Mosquitoes for Mosquito Control.” 90 Fed. Reg. 40829. The white paper, charge questions, background documents, and related supporting materials are available for public review and comment. Written comments on the peer review documents (white paper, charge questions, background documents, and related supported materials) are due September 22, 2025. The FIFRA SAP will consider and review the documents at a three-day virtual public meeting November 3-5, 2025. EPA called for public comment on the candidates being considered as ad hoc peer reviewers on August 20, 2025. EPA will post information on its website on how to register for the meeting and provide comments in October 2025.

The white paper notes that EPA’s Office of Pesticide Programs (OPP) is a risk-based program, meaning that both hazard and exposure are taken into consideration when evaluating the risk of pesticides, including GE mosquitoes. If either hazard or exposure is negligible, then the resulting risk is also considered negligible, and the safety standard can be met under FIFRA. EPA states that as part of the exposure assessment for human health risk for GE mosquitoes, it is relevant to consider the likelihood of the presence of GE females in the environment as female mosquitoes (but not males) bite and thus could expose humans to novel proteins if the novel proteins are present in the mosquito saliva.

According to EPA, demonstrating negligible exposure is conceptually straightforward because exposure is only plausible if a novel protein is present in the saliva of the female mosquitoes. EPA states that “this is the preferred method at this time.” Determining the parameters of those empirical tests is the focus of this SAP. As such, in a draft memorandum for developers (“Analysis of novel proteins in the saliva of pesticidal genetically engineered mosquitoes for mosquito control and associated design considerations for developers”) accompanying this white paper, EPA “is putting forward analytical methods that the Agency finds provide robust and conservative approaches to determining the absence of novel proteins in the saliva of female GE mosquitoes.” EPA notes that the approach is based on knowledge of the molecular techniques, mosquito biology, and review of publicly available science. EPA “finds that the approach and methods presented in that document will allow the demonstration of negligible presence of novel proteins in the saliva of female GE mosquitoes.”

EPA convened an SAP to evaluate the proposed molecular methods and provide feedback on case studies, including a case study for a GE mosquito that is currently under review for registration (OX5034 Aedes aegypti; EPA File Symbol: 93167-R; Docket ID: EPA-HQ-OPP-2024-0133). The other case studies are hypothetical cases intended to demonstrate additional acceptable methodologies presented in the memorandum for developers. EPA states that it also recognizes that in some cases novel proteins may be present in the saliva, which would then necessitate the full hazard characterization to be able to support a risk conclusion. Therefore, EPA is also asking the SAP questions on the hazard assessment, specifically which aspects of established guideline studies, weight-of-evidence approaches, and other information elements could support that part of the human health risk assessment.

Below is a chronological listing of the dates for the specific activities:

• September 4, 2025: Deadline to submit written comments on scientific and technical experts to be considered as ad hoc peer reviewers to assist the FIFRA SAP;
• September 22, 2025: Deadline to submit written comments on the peer review documents (white paper, charge questions, background documents, and related supporting materials);
• October 24, 2025: Deadline to submit a request for special accommodations to allow sufficient time for EPA to process the request before the meeting;
• October 27, 2025 (12:00 p.m. EDT): Deadline to register to be listed on the meeting agenda to make oral comments during the virtual meeting;
• October 30, 2025: Deadline to submit a written version of oral comments that will be made during the virtual meeting;
• November 3-5, 2025: FIFRA SAP public virtual meeting; and
• November 5, 2025: Deadline for those not making oral comments to register to receive the links to observe the meeting.