# toxicity

/tɑkˈsɪsəti/ (US) · /tɒksˈɪsɪti/ (UK) · CEFR B2 · Noun

Source: https://englishreference.com/word/toxicity
Updated: 2026-05-03

## Definition

the quality of being poisonous or harmful to living things. It can also describe a situation or relationship that is very negative and damaging to your mental health.

For teachers: the degree to which a substance can damage an organism, or the quality of being poisonous. In social contexts, refers to harmful, manipulative, or destructive behavior within a group or relationship.

## Examples

- The scientists are testing the toxicity of the new chemical.
- The manager resigned because the toxicity of the office environment was affecting his health.
- Environmental regulations aim to limit the toxicity of industrial runoff to protect local aquatic ecosystems from long-term damage.

## Usage notes

- Uncountable in most contexts; can be used with 'of' to specify the source of the harm.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.