Which LD50 value indicates a relatively non-toxic pesticide?

• A. 640 mg/kg
• B. 12,840 mg/kg
• C. 380 mg/kg
• D. 46 mg/kg

Answer: (B)

The LD50 (lethal dose for 50% of the population) value provides a measure of the toxicity of a substance, including pesticides. A higher LD50 value typically indicates a lower level of toxicity, meaning that more of the substance would be needed to cause harm to half of a test population.

In this context, a value of 12,840 mg/kg suggests that a considerably large amount of the pesticide would be required to be lethal to half of the tested population, indicating that it is relatively non-toxic compared to the other options listed. Lower LD50 values, such as those represented by the other choices, signify higher toxicity, as less of the substance is needed to cause significant harm.

Thus, understanding the implications of the LD50 values helps in assessing the safety and risks associated with pesticide use. The higher the LD50, the safer the pesticide tends to be, especially when used according to label instructions.