What does toxicity mean?
Toxicity is the degree to which a substance, organism, or environment is poisonous. In technical and public-health contexts, it describes a measurable harmful effect or the presence and concentration of toxic substances, with the seriousness of exposure often depending on dose, route, and duration. The word can also be used figuratively for the damaging influence of hostile rhetoric, abusive behaviour, or an unwelcoming social atmosphere. In this extended sense, toxicity is more evaluative than simply describing one isolated incident: it often suggests a persistent pattern that makes communication, learning, or participation difficult. Unlike the related adjective toxic, which can label a particular substance or person, toxicity names the quality or degree itself. The distinction allows speakers to discuss harm without merely calling someone or something “poisonous,” while retaining the vivid idea of poison for language or environments that erode wellbeing.
nounThe degree to which a substance, organism, or environment is poisonous, or the presence of poisonous substances in an environment. Figuratively, it denotes the harmful, corrupting, or obstructive character of an influence, behaviour, or social environment.
- The quality or degree of being poisonous, especially as a property of a substance or organism.
- The presence or concentration of poisonous substances in an environment.
- The severely harmful, corrupting, or obstructive influence of behaviour, rhetoric, or social conditions.
"The researchers tested the toxicity of the chemical on aquatic organisms before releasing it into the river."
"Low levels of lead in the water were associated with minimal toxicity."
"The forum tried to reduce the toxicity of online debate by moderating comments."
The plural is used when referring to different poisonous qualities or effects, especially in scientific or comparative contexts.
"The study compares the toxicities of several industrial solvents."
The word’s Greek root, toxikon, meant poison for arrows—long before chemistry gave us ways to measure toxicity.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does toxicity come from?
Toxicity was formed from toxic plus the noun-forming suffix -ity. The adjective toxic comes through Latin toxicus, meaning “poisonous,” from Greek toxikos, “poisonous,” which is related to toxikon, “poison for arrows.” The abstract noun toxicity developed in scientific English to express the condition or degree of being poisonous and was later extended figuratively to describe harmful social and communicative influences.
How toxicity is actually used
In technical writing, toxicity is usually treated as a measurable property of a substance, organism, or exposure. In figurative use, it is strongly evaluative and often denotes persistently hostile, insulting, or socially damaging communication. It can sound more formal or institutional than simply saying that something is harmful or nasty.