LD50 (lethal dose)

LD50, or lethal dose 50%, is a standard measurement used in toxicology to describe the amount of a substance required to cause death in 50% of a tested population, typically animals. It helps assess how toxic a substance is by indicating its potency; the lower the LD50, the more toxic the substance. For example, if a small dose of a chemical causes half the test subjects to die, it has a low LD50 and is considered highly toxic. This measurement helps compare the hazards of different substances and informs safety guidelines.