True or False: A smaller LD50 value indicates that less chemical is required to be fatal, making the pesticide more poisonous.

A smaller LD50 value signifies that less of a chemical is needed to achieve a lethal effect in 50% of a test population. This means that the substance is more toxic or poisonous, as it requires a smaller amount to be fatal. The LD50 (lethal dose for 50% of the population) is a standard measure of acute toxicity; therefore, as the LD50 decreases, the toxicity of the substance increases. Hence, if a pesticide has a lower LD50, it is indeed considered more poisonous compared to one with a higher LD50, which would require a greater amount to cause the same lethal effect. This fundamental understanding of toxicology is crucial in evaluating and comparing the safety and risks associated with various pesticides.