What does a lethal dose refer to?

A lethal dose refers specifically to the quantity of a substance that is capable of causing death, particularly when tested on laboratory animals. This term is often associated with measurements such as LD50, which indicates the dosage at which 50% of a test population is expected to succumb to the effects of the substance. Understanding lethal dose is critical in toxicology and safety assessments, as it helps in determining the risk posed by certain chemicals or substances to humans and the environment.

The other choices do not accurately define lethal dose. For instance, while serious injury can occur from various amounts of exposure, it does not necessarily lead to death or quantify the lethal aspect. The minimum exposure for toxicity may indicate a lower threshold for effects but does not specify death. Lastly, the highest allowable dose in workplace safety relates to regulatory limits set for safe exposure and not the lethal potential of a substance.