A toxicant is any toxic substance. In popular usage, the term is often used to denote substances made by humans or introduced into the environment by human activity, in contrast to toxins, which are toxicants produced naturally by a living organism.
There are numerous types of toxicant.
Biocides include many toxicants specifically developed to fight pests.
Toxins are naturally produced toxicants, often as part of a metabolic process or similar.
- Cope, W. Gregory; Leidy, Ross B. "Classes of Toxicants: Use Classes". In Hodgson, Ernest. A Textbook of Modern Toxicology (3 ed.). John Wiley & Sons.
A toxin is a toxicant that is produced by a living organism and is not used as a synonym for toxicant—all toxins are toxicants, but not all toxicants are toxins. Toxins, whether produced by animals, plants, insects, or microbes are generally metabolic products that have evolved as defense mechanisms for the purpose of repelling or killing predators or pathogens.
- "National Cancer Institute Dictionary: definition for 'toxicant'".
- "National Cancer Institute Dictionary: definition for 'toxin'".
- "toxic, toxin, toxicant". National Geographic Style Manual. National Geographic Society. Retrieved 2014-04-05.