The most commonly used measure of acute toxicity of a substance. Refers to the amount of a substance required to kill half (50%) of a test animal population (usually rodents) from a single dose. Units are milligrams of substance per kilogram of body weight of the animal.
The dose of a chemical that kills 50 percent of the group of test animals. It is usually expressed as milligrams of chemical per kilogram of body weight of the test animal.
A statistically or graphically estimated dose that is expected to be lethal to 50% of a group of organisms under specified conditions.
The dose at which 50% of laboratory animals die within a few days.
A calculated dose of a substance which is expected to cause the death of 50 percent of the entire defined experimental animal population.
Also referred to as LD50, the dose of a toxicant that will kill 50 percent of test organisms within a designated period of time; the lower the LD 50, the more toxic the compound.