The concentration of a substance that would be expected to kill 50% of organisms. Despite its deficiencies, the LC50 estimate was a regulatory requirement in drug testing until it was superseded by more sensitive measurements. The LD50 is the median lethal dose, effectively the same measurement. The median lethal time (TL50) is the average time interval during which 50% of a given population will die following acute administration of a chemical or physical agent. In all cases it is essential to specify the conditions.
Subjects: Medicine and Health.