What does a lower LD50 indicate?

What does a lower LD50 indicate?

• A. Less toxic
• B. More toxic
• C. The same toxicity
• D. No toxicity

Answer: (B)

LD50 is the amount of a substance needed to kill 50% of a test population. A lower LD50 means only a small amount is required to reach that lethal level, so the substance is more toxic because it has greater potency. For example, if one chemical has an LD50 of 2 mg/kg and another has 20 mg/kg, the first is more toxic since much less of it is needed to cause death in half the population. Keep in mind that LD50 values depend on factors like species, route of exposure, and test conditions, and they reflect acute toxicity rather than long-term or chronic effects. In short, a lower LD50 indicates higher toxicity.

LD50 is the amount of a substance needed to kill 50% of a test population. A lower LD50 means only a small amount is required to reach that lethal level, so the substance is more toxic because it has greater potency. For example, if one chemical has an LD50 of 2 mg/kg and another has 20 mg/kg, the first is more toxic since much less of it is needed to cause death in half the population. Keep in mind that LD50 values depend on factors like species, route of exposure, and test conditions, and they reflect acute toxicity rather than long-term or chronic effects. In short, a lower LD50 indicates higher toxicity.