What is the definition of toxicity?

• A. The capacity of any substance to produce short-term or long-term injury or death.
• B. The amount of a substance required to produce an effect.
• C. The occurrence of environmental damage due to a chemical.
• D. The likelihood that exposure will occur.

Answer: (A)

Toxicity is the inherent capacity of a substance to cause harm, including short-term injury, long-term health effects, or death, if exposure occurs. This means toxicity describes how dangerous a chemical could be regardless of how much someone is exposed to. The amount required to produce an effect is dose (or potency), which depends on conditions and isn’t the same as the substance’s inherent toxic potential. Environmental damage describes ecological impact, not the substance’s intrinsic ability to harm, and the likelihood of exposure relates to exposure risk rather than the substance’s toxic potential. So the correct idea is that toxicity is about the substance’s inherent potential to cause harm.