The toxicity of a substance refers to its ability to cause injury, while what term refers to the risk or chance of harm from using the pesticide?

The term that refers to the risk or chance of harm from using a pesticide is "hazard." Hazard is a broader concept that incorporates not only the inherent toxicity of a substance but also factors such as exposure levels, the conditions under which the pesticide is used, and the potential for that substance to cause harm in various situations. Essentially, hazard reflects the likelihood that harmful effects will occur under specific circumstances.

In the context of pesticides, it's important to understand that a substance can be highly toxic (meaning it can cause severe injury or death) yet may pose a low hazard in practice if it is used correctly and exposure is minimized. This distinction is critical in pesticide safety, as it guides applicators in understanding not just the toxicity of the chemicals they use, but also the practical risk involved in applying them.

Other terms mentioned, such as toxicity level and safety index, focus more on quantifying effects or comparing substances rather than assessing the overall risk associated with their use in real-world applications. Risk assessment is a process, not a term defining risk; while it certainly plays a part in assessing hazard, it does not encapsulate the concept entirely.