A toxin (Greek:, toxikon) is a poisonous substance produced by living cells or organisms (although humans are technically living organisms, man-made substances created by artificial processes usually aren't considered toxins by this definition). For a toxic substance not produced by living organisms, "toxicant" is the more appropriate term, and "toxics" is an acceptable plural. Toxins can be small molecules, peptides, or proteins that are capable of causing disease on contact with or absorption… (More on Toxin)