Structural Pest Control Applicator Practice Exam

The smaller the LD50 value, what can be inferred about the pesticide's toxicity?

1. It requires more chemical to be fatal

2. It is less poisonous

3. It is more poisonous

4. It is equally toxic

The correct answer is: It is more poisonous

The LD50 value, which stands for lethal dose for 50% of the test population, is a standard measurement used to assess the toxicity of substances, including pesticides. A smaller LD50 value indicates that a lower dose of the pesticide is required to achieve a lethal effect in 50% of the population being tested. This means that the pesticide is more potent or toxic, as it can cause fatal effects at a lower quantity compared to substances with a higher LD50 value. Consequently, this relationship allows you to infer that pesticides with lower LD50 values are more poisonous, making option C the most accurate answer in this context.