Similar term(s): lethal dose 50, median lethal dose, LC50.
The amount of a chemical that is lethal to one-half (50%) of the experimental animals exposed to it.
LD50s are usually expressed as the weight of the chemical per unit of body weight (mg/kg).
It may be fed (oral LD50), applied to the skin (dermal LD50), or administered in the form of vapors (inhalation LD50).
Source: University of Guelph