Claim: Ricin is poisonous.

Toxicity is the degree to which a substance can damage an organism . Toxicity can refer to the effect on a whole organism , such as an animal , bacterium , or plant , as well as the effect on a substructure of the organism , such as a cell -LRB- cytotoxicity -RRB- or an organ such as the liver -LRB- hepatotoxicity -RRB- . By extension , the word may be metaphorically used to describe toxic effects on larger and more complex groups , such as the family unit or society at large . Sometimes the word is more or less synonymous with poisoning in everyday usage .   A central concept of toxicology is that the effects of a toxin are dose-dependent ; even water can lead to water intoxication when taken in too high a dose , whereas for even a very toxic substance such as snake venom there is a dose below which there is no detectable toxic effect . Toxicity is species-specific , making cross-species analysis problematic . Newer paradigms and metrics are evolving to bypass animal testing , while maintaining the concept of toxicity endpoints .