Chemical materials developed to assist in the production of food, feed, and fiber include herbicides, insecticides, fungicides, and other pesticides. Pesticides are chemicals that play an important role in increasing crop yield and mitigating crop losses. These work to keep insects and other animals away from crops to allow them to grow undisturbed, effectively regulating pests and diseases.
Disadvantages of pesticides include contamination of the ground and water (see persistent organic pollutants). They may be toxic to non-target species, including birds, fish, pollinators,  as well as the farmworkers themselves.