Illinois General Standards Pesticide Practice Exam

The term LD 50, which stands for "lethal dose, 50 percent," is a specific measurement used to define the toxicity of a pesticide or any chemical substance. It refers to the dose required to kill half of a selected population of test animals, typically within a specified time frame. This measurement is vital for evaluating the potential risk of substances to both humans and non-target organisms.

Understanding LD 50 helps in comparing the relative toxicity of different chemicals; a lower LD 50 value indicates a more toxic substance (meaning a smaller amount is sufficient to cause death), while a higher value suggests lower toxicity. This metric is particularly important for ensuring safety in pesticide application and helps applicators make informed decisions about the products they use.