A pesticide, sometimes referred to as a biocide, is a general term to describe substances used for preventing, destroying, repelling, or mitigating any biological pest. The most widely used types of pesticides in Canada include herbicides for weed control, insecticides for insect control and fungicides for fungi control. There are many other types of pesticides such as rodenticides to control rodents, or antimicrobials and disinfectants to control bacteria and viruses. Ideally, a pesticide should be harmful to the pests of interest only and not to other, non-target organisms.

Pesticides have provided incredible advantages to societies in many ways, for example, by increasing crop yields and therefore bolstering food availability and the economy. Unfortunately, their use can have negative impacts as well. The agricultural, pesticide-producing and scientific communities are continually challenged to find sustainable solutions. This is a very difficult goal to achieve, especially when adverse effects to the environment from the chemicals used are not always known.