A<unk>  is any toxic substance.<unk> s can be poisonous and they may be man-made or naturally occurring. By contrast, a toxin is a poison produced naturally by an organism (e.g. plant, animal, insect). The different types of<unk> s can be found in the air, soil, water, or food.
Toxicant
Inhalant
Cathartic
Cold
Toxoid
Neuroskeptic
Co-carcinogen
Heteroecious