In general, a higher LD50 value means lower acute toxicity.

• A. True
• B. False
• C. Not enough information
• D. It depends on exposure route

Answer: (B)

LD50 is the dose needed to kill 50% of a tested group under specific conditions. A higher LD50 generally suggests lower acute toxicity for that particular route of exposure, but saying this applies “in general” is not accurate. LD50 values are highly dependent on how exposure occurs—oral, dermal, inhalation, etc.—and can differ dramatically between routes for the same substance. A chemical may have a high LD50 by mouth but be far more toxic by inhalation, so you can’t universally claim that a higher LD50 means lower acute toxicity across all scenarios. Additionally, LD50 is just one metric of acute toxicity and doesn’t address sublethal effects, chronic exposure, or other routes of entry.