Dermal LD50 refers to the dose that kills 50% of test animals via

Dermal LD50 refers to the dose that kills 50% of test animals via

• A. Dermal exposure
• B. Oral exposure
• C. Inhalation exposure
• D. Inhalation exposure and oral exposure

Answer: (A)

LD50 is the median lethal dose—the amount of chemical needed to kill 50% of the test population under defined conditions. Dermal LD50 specifically refers to the dose that, when the substance is applied to the skin, would be lethal to 50% of the animals. This measures toxicity by skin contact and is distinct from toxicity measured by other routes. Inhalation has its own measure (often LC50, the lethal concentration in air), and ingestion has its own oral LD50. Because the question asks about the dose that kills by skin exposure, dermal LD50 is the correct interpretation.

LD50 is the median lethal dose—the amount of chemical needed to kill 50% of the test population under defined conditions. Dermal LD50 specifically refers to the dose that, when the substance is applied to the skin, would be lethal to 50% of the animals. This measures toxicity by skin contact and is distinct from toxicity measured by other routes. Inhalation has its own measure (often LC50, the lethal concentration in air), and ingestion has its own oral LD50. Because the question asks about the dose that kills by skin exposure, dermal LD50 is the correct interpretation.