LD50 stands for which definition?

LD50 stands for which definition?

• A. Lethal dose 50% fatal
• B. Lethal dose 50% nonfatal
• C. Lowest dose 50% fatal
• D. Lethal dose 100% fatal

Answer: (A)

LD50 means the dose that would be expected to kill half of the test population under the specified conditions. It’s a median lethal dose, usually expressed per body weight (for example, mg of substance per kg of body weight). This metric lets toxicologists compare acute toxicity between substances: a higher LD50 requires a larger dose to reach 50% mortality, indicating lower acute toxicity, while a lower LD50 indicates higher acute toxicity. It specifically refers to lethal outcomes, not nonfatal effects, and it is about dose rather than concentration in the air.

LD50 means the dose that would be expected to kill half of the test population under the specified conditions. It’s a median lethal dose, usually expressed per body weight (for example, mg of substance per kg of body weight). This metric lets toxicologists compare acute toxicity between substances: a higher LD50 requires a larger dose to reach 50% mortality, indicating lower acute toxicity, while a lower LD50 indicates higher acute toxicity. It specifically refers to lethal outcomes, not nonfatal effects, and it is about dose rather than concentration in the air.