LD50 (lethal dose)
LD50 (lethal dose) is a term used to describe a lethal dose 50, or median lethal dose: the amount of a pharmacological or toxic substance (such as ionizing radiation) that causes death in 50% of a group of experimental animals. For each LD50 the species and weight of the animal and the route of administration of the substance are specified. LD50s are used both in toxicology and in the *bioassay of therapeutic compounds. See also Toxicity and Green Chemistry Eco Fashion Dictionary.