Pesticides: Frequently Asked Questions

Understand what pesticides are and what they're not, what they control, if they're harmful and who controls them.

What is a pesticide?

A pesticide is any substance used to control or repel a pest or to prevent the damage that pests may cause. Pests can be insects, mice and other animals, unwanted plants (weeds), fungi, or microrganisms like bacteria and viruses.

The term "pesticide" includes insecticides, herbicides, and fungicides and other substances used to control pests.

Examples of pesticide products and the pest(s) it controls: (adapted from the US Environmental Protection Agency)

  • Algaecides - Control algae in lakes, canals, swimming pools, water tanks, and other sites.

  • Anti-fouling agents - Kill or repel organisms that attach to underwater surfaces, such as boat bottoms.

  • Anti-microbials - Kill microorganisms (such as bacteria and viruses).

  • Attractants - Attract pests (for example, to lure an insect or rodent to a trap). (However, food is not considered a pesticide when used as an attractant.)

  • Biocides - Kill microorganisms.

  • Disinfectants and sanitizers - Kill or inactivate disease-producing microorganisms on inanimate objects.

  • Fungicides - Kill fungi (including blights, mildews, molds, and rusts).

  • Fumigants - Produce gas or vapor intended to destroy pests in buildings or soil.

  • Herbicides - Used to control unwanted plants (weeds). Herbicides are often combined with other materials such as fertilizer in "weed and feed" products. These products are also considered a pesticide.

  • Insecticides - Kill insects and other arthropods.

  • Miticides (also called acaricides) - Kill mites that feed on plants and animals.

  • Microbial pesticides - Microorganisms that kill, inhibit, or out compete pests, including insects or other microorganisms.

  • Molluscicides - Kill snails and slugs.

  • Nematicides - Kill nematodes (microscopic, worm-like organisms that feed on plant roots).

  • Ovicides - Kill eggs of insects and mites.

  • Pheromones - Chemicals used to modify the mating behavior of insects by attracting them to a site or trap.

  • Repellents - Repel pests, including insects (such as mosquitoes) and birds.

  • Rodenticides - Control mice, rats and other rodents.

The term pesticide also includes these substances:

  • Defoliants - Cause leaves or other foliage to drop from a plant, usually to facilitate harvest such as in potato production.

  • Desiccants - Promote drying of living tissues, such as unwanted plant tops.

  • Insect growth regulators - Disrupt the molting, maturity from pupal stage to adult, or other life stages of insects.

  • Plant growth regulators - Substances (excluding fertilizers or other plant nutrients) that alter the expected growth, flowering, or reproduction rate of plants.

What are some pesticides I might find around my home?

Many household products are pesticides. Did you know that all of these common products are considered pesticides?

  • Cockroach sprays and baits.
  • Insect repellents for personal use.
  • Rat and other rodent poisons.
  • Flea and tick sprays, powders, and pet collars.
  • Kitchen, laundry, and bath disinfectants and sanitizers.
  • Products that kill mold and mildew.
  • Some lawn and garden products, such as weed killers or
    'weed and feed' products.
  • Some swimming pool chemicals.

Are pesticides harmful?

By their very nature, most pesticides create some risk of harm to humans, animals, or the environment because they are designed to kill or otherwise adversely affect living organisms. At the same time, pesticides can be useful because of their ability to kill potential disease-causing organisms and control insects, weeds, and other pests. Biologically-based pesticides, such as pheromones and microbial pesticides, are becoming
increasingly popular and often are safer than traditional chemical pesticides.

What about pest control devices?

EPA also has a role in regulating devices used to control pests. More specifically, a "device" is any instrument or contrivance (other than a firearm) intended for trapping, destroying, repelling, or mitigating any pest. A mousetrap is an example of a device. Unlike pesticides, EPA does not require devices to be registered with the Agency. Devices are subject to certain labeling, packaging, record keeping, and import/export requirements, however.

Who regulates pesticides?

In the United States, the Office of Pesticide Programs of the Environmental Protection Agency is chiefly responsible for regulating pesticides. Each state, such as Wisconsin, also enforces federal pesticide regulations along with state pesticide regulations.

All pesticides must be registered with EPA and the products must be registered with the state in which they are sold.

What is not a pesticide?

The US definition of pesticides is quite broad, but it does have some exclusions:

  • Drugs used to control diseases of humans or animals (such as livestock and pets) are not considered pesticides; such drugs are regulated by the Food and Drug Administration.

  • Fertilizers, nutrients, and other substances used to promote plant survival and health are not considered plant growth regulators and thus are not pesticides.

  • Biological control agents, except for certain microorganisms, are exempted from regulation by EPA. (Biological control agents include beneficial predators such as birds or ladybugs that eat insect pests.)

  • Finally, EPA has also exempted certain other low-risk substances, such as cedar chips, garlic, and mint oil.

  • General Information
  • Animal Poisoning (Toxic Response)
  • ATCP 29 Pesticide Use & Control Rule Revision
  • Business and Farms
  • Clean Sweep
  • Endangered Species
  • Agrichemical Management Bureau Annual Report
  • Pesticide Product Registration
  • Pesticide Certification and Licensing
  • Frequently Asked Questions
  • Filing a Pesticide Complaint
  • Homeowners, Renters & General Public
  • Resources
  • Pesticide Databases
  • DriftWatch Program
  • Special Pesticide Registrations