Jump to main content.

Pesticide Inert Ingredients

PLEASE NOTE: Some or all of the content on this web page has been moved to a new location. One or more redirect links are provided immediately to the right of this notice to get you to the new content.

  • Inert Ingredients - Overview & Guidance
  • Inert Ingredient Frequently Asked Questions (PDF)
  • List of Trade Name Inert Ingredients (PDF)

  • Inert Resources

    Inert Ingredient Assessment Branch
    PV Shah, Branch Chief

    Questions or comments related to the inert ingredient guidance documents and the inert ingredients listings can be directed to the Inert Ingredient Assessment Branch (IIAB) at inertsbranch@epa.gov.

    Note: The List Category policy, created in 1987, has now served its purpose as a tool for prioritizing the evaluation of chemicals.  Now that reassessment of food tolerances/tolerance exemptions under the Food Quality Protection Act (FQPA) is complete, there are no longer inerts classified as List 1, 2, or 3.  All-food use inert ingredient tolerances and tolerance exemptions are considered to be safe when used according to the conditions set forth in the CFR's text and tables. The “4A” category is still being used for the purposes of FIFRA Section 25(b), and USDA is still utilizing “List 4” for their National Organic Program.  For non-food inert ingredients, the 1987 List Category policy remains pertinent (including labeling) for those identified as "List 1" (toxicological concern). For informational purposes you can still access EPA’s old inert list categories. These lists are no longer updated by the Agency.

    What is an inert ingredient?

    Pesticide products contain both "active" and "inert" ingredients. The terms "active ingredient" and "inert ingredient" are defined by the federal law that governs pesticides (Federal Insecticide, Fungicide, and Rodenticide Act [FIFRA]). An active ingredient is one that prevents, destroys, repels, or mitigates a pest, or is a plant regulator, defoliant, desiccant or nitrogen stabilizer. By law, the active ingredient must be identified by name on the pesticide product's label together with its percentage by weight.

    All other ingredients in a pesticide product are called "inert ingredients." An inert ingredient means any substance (or group of similar substances) other than an active ingredient that is intentionally included in a pesticide product. Called “inerts” by the law, the name does not mean non-toxic.

    Pesticide products often contain more than one inert ingredient. Inert ingredients play key roles in the effectiveness of pesticides. Examples include inerts that prevent caking or foaming, extend product shelf-life, or solvents that allow herbicides to penetrate plants.


    Publications | Glossary | A-Z Index | Jobs

    Local Navigation

    Jump to main content.