TOXICITY

n. quality of being poisonous; degree to which a substance is toxic

Toxicity is the degree to which something is able to produce illness or damage to an exposed organism. Toxicity can refer to the effect on a whole organism, such as a human or a bacterium or a plant, or to a substructure, such as a cell (cytotoxicity) or an organ (organotoxicity such as the liver (hepatotoxicity). 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".
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Noun
1. the degree to which something is poisonous
(hypernym) definite quantity
(hyponym) cytotoxicity
2. grave harmfulness or deadliness
(synonym) perniciousness
(hypernym) unwholesomeness, morbidness, morbidity

The degree to which a substance or mixture of substances can harm humans or animals. Acute toxicity involves harmful effects in an organism through a single or short-term exposure. Chronic toxicity is the ability of a substance or mixture of substances to cause harmful effects over an extended period, usually upon repeated or continuous exposure sometimes lasting for the entire life of the exposed organism. Subchronic toxicity is the ability of the substance to cause effects for more than one year but less than the lifetime of the exposed organism.

potential of a substance to exert a harmful effect on humans or animals, often used to refer to side effects of drugs.