The Association of American Pesticide Control Officials (AAPCO) FIFRA 25(b) Workgroup has released updated guidance intended to aid registrants in developing product efficacy data to support claims on products that qualify for the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Section 25(b) minimum risk exemption when seeking state registration.
Under FIFRA Section 25(b), as detailed in Title 40 of the Code of Federal Regulations (40 C.F.R. Section 152.25(f)), the U.S. Environmental Protection Agency (EPA) exempts certain products from federal registration when certain conditions are met. Similar to other FIFRA-regulated products, one key condition for 25(b) minimum risk products is that the label statements must not be false or misleading as described in 40 C.F.R. Section 156.10(a)(5).
State lead agencies may require efficacy data to confirm that label statements are not false or misleading. If the claims are not supported by data, the states may conclude the product label to be false or misleading and therefore does not qualify for the 25(b) minimum risk exemption or state registration.
Each state may have different label and/or data requirements. In an effort to facilitate collaboration and consistency among states and industry, AAPCO created the 25(b) Workgroup. The 25(b) Workgroup has developed guidance to help companies comply with state requirements for product formulation and labeling. The product efficacy guidance is a “living document” periodically updated; the previous update was released in January 2019. AAPCO notes that adherence to the guidance, as with prior versions, does not guarantee that a product will be accepted in all states.
The guidance document currently includes three chapters:
- Chapter 1 — General 25(b) Study Conduct & Data Collection Expectations;
- Chapter 2 — Guidance & Definitions Specific to 25(b) Arthropod Testing; and
- Chapter 3 — Guidance & Definitions Specific to 25(b) Antimicrobial & SurfaceFungicide Testing.
The updated AAPCO 25(b) efficacy data guidance marks a major shift from the past versions that presented guidance in general terms and focused heavily on efficacy benchmarks for insecticide repellents. The updated version includes an introductory chapter that provides an overview of general study requirements and expectations, as well as a glossary of terms relevant to efficacy studies and data collection.
In Chapter 2, Guidance for Arthropod Testing, the benchmarks for efficacy claims remain the same as in prior versions, although reference is now made to methodologies outlined in EPA’s 810 Performance Test Guidelines, Invertebrate Control. Definitions and clarifications are provided that are specific to repellency testing and historically were often misunderstood (e.g., “bite,” “crossing,” “Protection Time”).
Most notably, in Chapter 3, the guidance now includes guidance on efficacy testing and requirements for antimicrobial claims, referencing EPA’s 810 Performance Test Guidelines, Antimicrobial Efficacy Testing for help with study designs. The guidance provides an explicit benchmark for antimicrobial claims — “should demonstrate ≥60% efficacy” if the label “claims to kill a microbial pest (e.g., bacteria, fungi, algae).”
As true for all 25(b) products, to meet the conditions of a 25(b) pesticide, an antimicrobial product is not permitted to make public health claims (i.e., to make claims to control organisms that pose a threat to human health).
- Non-Public Health Claim — An antimicrobial pesticide is considered to make a non-public health claim if the pesticide product bears a claim to control microorganisms of economic or aesthetic significance, where the presence of the microorganism would not normally lead to infection or disease in humans. Examples of non-public health claims include, but are not limited to: algaecides, slimicides, preservatives, and products for which a pesticidal claim with respect to odor sources is made.
- Public Health Claim — An antimicrobial pesticide is considered to make a public health claim if the pesticide product bears a claim to control pest microorganisms that pose a threat to human health, and whose presence cannot readily be observed by the user, including but not limited to, microorganisms infectious to man in any area of the inanimate environment. Examples of public health claims include, but are not limited to: claims to kill or eradicate Mycobacterium tuberculosis, Escherichia coli (E. coli), or fungi infectious to man; or claims to purify water.
The updated guidance contains placeholders for three future chapters, Chapters X, Y, and Z, to provide guidance on: Herbicides; Fungicides for Plant Diseases; and Vertebrate Testing.
The guidance becomes effective 18 months after its Effective Date of May 1, 2026. States that weighed-in agreed that any product renewals falling within this period will not be impacted. But any new products, or existing products wishing to make new efficacy claims after May 1, 2026, should adhere to the updated guidance. Although this recent guidance includes input from industry, as well as some state lead agencies, AAPCO does not provide a list of states that acknowledge concurrence and does provide the disclaimer that use of the guidance is not a guarantee of acceptance in all states. It is recommended that registrants continue to contact directly the states to confirm data requirements.
Commentary
This updated guidance expands the guidance for states to include antimicrobial pesticides but continues to track the EPA regulatory tightrope of communicating to a consumer the distinction between what is or is not a “public health” claim. Since EPA began its 25(b) list for certain pesticides, it has maintained that as long as several conditions are met, including that the label does not make a public health claim, it is exempt from federal registration. Including a state benchmark for efficacy for non-public health claims for pesticide products may result in more review than EPA provides for similar federal labels.
The 25(b) list includes various botanical and other ingredients (example: geranium oil, thyme, or peppermint); such products are exempt from EPA if, among other conditions, no public health claim is on the label. Many such products are marketed as “natural” pesticides and labeled as “safe” when used as directed, but since they are exempt, there is no EPA review of the product or information on the label. This is widely held for insecticides and insect repellants and would also apply to antimicrobials.
Under the provisions of the 25(b) list, there is, however, an important bureaucratic distinction that matters greatly to EPA but not likely understood by consumers: if the repellant label includes “public health claims” — such as “repels mosquitoes that may cause West Nile Virus” or “kills ants and flies that can spread disease” — those public health claims would trigger EPA review, and require the product to have data showing that it works.
If the 25(b) product label simply states, “repels mosquitoes and safe for children” or “kills ants and safe to use around pets,” it is not a public health claim, and is not subject to EPA review. EPA does mandate that the label cannot have any false or misleading statements, but EPA does not conduct a review, and the level of review and data requirements across the states varies. This potential confusion was raised to EPA in a 2006 petition about 25(b) insect repellants and in 2007 EPA committed to address this issue by proposing changes to its 25(b) regulations. In the meantime, changes to address possible consumer confusion over “kills insects” versus “kills insects that may cause disease” have yet to be proposed since EPA’s petition response in 2007.