What term describes the degree to which a chemical is poisonous?

The term that describes the degree to which a chemical is poisonous is toxicity. Toxicity refers specifically to the inherent ability of a substance to cause harm or adverse effects in living organisms. This can include a wide range of effects, from mild irritation to severe health consequences or even death, depending on the dose and the nature of the chemical in question.

In toxicology, understanding toxicity is crucial because it helps determine how much of a substance is harmful and under what conditions. It can vary significantly among different chemicals and is measured through various tests and studies, often expressed as lethal dose (LD50), which is the amount of a substance that causes death in 50% of a test population.

Exposure pertains to the contact between a chemical and an organism, which is necessary to assess the potential for harm but does not directly measure how poisonous a compound is. Hazard describes the potential for a substance to cause harm under specific conditions but encompasses more than just toxicity, including factors such as exposure scenarios and vulnerability of the individuals involved. Risk combines the concepts of hazard and exposure, assessing the likelihood and severity of harmful effects occurring in a given situation.

Understanding toxicity is fundamental for individuals working with chemicals, including those involved in pesticide application, to ensure safety and compliance with regulations.