Basic Information about Pesticide Ingredients

Pesticide products contain both “active” and “inert” ingredients:

  • An “active ingredient” prevents, destroys, repels, or mitigates a pest, or is a plant regulator, defoliant, desiccant, or nitrogen stabilizer.
  • All other ingredients are called “inert ingredients” by federal law. They are important for product performance and usability.
    Active Ingredients

    Active ingredients are the chemicals in a pesticide product that act to control the pests. Active ingredients must be identified by name on the pesticide product’s label together with its percentage by weight.

    There are several categories of active ingredients:

    • Conventional, which are all ingredients other than biological pesticides and antimicrobial pesticides.
    • Antimicrobial, which are substances or mixtures of substances used to destroy or supress the growth of harmful microorganisms whether bacteria, viruses, or fungi on inanimate objects and surfaces.
    • Biopesticides, which are types of ingredients derived from certain natural materials.
      Inert Ingredients

      Pesticide products contain at least one active ingredient and other intentionally added inert ingredients. Called “inert ingredients” by the federal law, they are combined with active ingredients to make a pesticide product. Inerts are chemicals, compounds, and other substances, including common food commodities (e.g., certain edible oils, spices, herbs) and some natural materials (e.g., beeswax, cellulose).

      The name “inert” does not mean non-toxic. All inert ingredients must be approved by EPA before they can be included in a pesticide. We review safety information about each inert ingredient before approval. If the pesticide will be applied to food or animal feed, a food tolerance is required for each inert ingredient in the product, and we may limit the amount of each inert ingredient in the product.

      Inert ingredients play key roles in pesticide effectiveness and product performance. Examples of functions inerts can serve include:

      • Act as a solvent to help the active ingredient penetrate a plant’s leaf surface.
      • Improve the ease of application by preventing caking or foaming.
      • Extend the product’s shelf-life.
      • Improve safety for the applicator.
      • Protect the pesticide from degradation due to exposure to sunlight.

      Under federal law, the identity of inert ingredients is confidential business information. The law does not require manufacturers to identify inert ingredients by name or percentage on product labels. In general, only the total percentage of all inert ingredients is required to be on the pesticide product label.

      Information on inert ingredients:
      Inert Ingredients Overview and Guidance
      Inert Ingredient Regulation
      Other/Inert Ingredients in Pesticides EXIT
      Evaluating Pesticide Ingredients
      Before manufacturers can sell pesticides in the United States, EPA must evaluate them thoroughly to ensure that they meet federal safety standards to protect human health and the environment. We grant a “registration” or license that permits a pesticide’s distribution, sale, and use only after the company meets the scientific and regulatory requirements.

      In evaluating a pesticide registration application, we assess a wide variety of potential human health and environmental effects associated with use of the pesticide. Potential registrants must generate scientific data necessary to address concerns pertaining to the:

      • identity,
      • composition,
      • potential adverse effects, and
      • environmental fate

      of each pesticide. The data allow us to evaluate whether a pesticide could harm certain nontarget organisms and endangered species. We evaluate both the active ingredient and the products in which the active ingredient is used.

      We regulate pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act. See more information on these pesticide categories:

      • Conventional pesticide registration
      • Antimicrobial pesticide registration
      • Biopesticide registration
    Types of Pesticides

    There are many different types of pesticides, each is meant to be effective against specific pests. The term “-cide” comes from the Latin word “to kill.”

    Algaecides are used for killing and/or slowing the growth of algae.

    Antimicrobials control germs and microbes such as bacteria and viruses.

    Biopesticides are made of living things, come from living things, or they are found in nature.

    Desiccants are used to dry up living plant tissues.

    Defoliants cause plants to drop their leaves.

    Disinfectants control germs and microbes such as bacteria and viruses.

    Fungicides are used to control fungal problems like molds, mildew, and rust.

    Herbicides kill or inhibit the growth of unwanted plants, aka weeds.

    Illegal and Counterfeit Pesticides are imported or sold illegally.

    Insecticides are used to control insects.

    Insect Growth Regulators disrupt the growth and reproduction of insects.

    Minimum Risk Pesticides are exempt from EPA registration, but many states require them to be registered.

    Miticides control mites that feed on plants and animals. Mites are not insects, exactly.

    Molluscicides are designed to control slugs, snails and other molluscs.

    Mothballs are insecticides used to kill fabric pests by fumigation in sealed containers.

    Natural and Biological Pesticides control pests using things found in nature, or man-made versions of things found in nature.

    Ovicides are used to control eggs of insects and mites.

    Pheromones are biologically active chemicals used to attract insects or disrupt their mating behavior. The ratio of chemicals in the mixture is often species-specific.

    Plant Growth Regulators are used to alter the growth of plants. For example, they may induce or delay flowering.

    Repellents are designed to repel unwanted pests, often by taste or smell.

    Rodenticides are used to kills rodents like mice, rats, and gophers.

    Synergists make certain pesticides more effective, but they are not effective when used alone.

    Wood Preservatives are used to make wood resistant to insects, fungus and other pests.