Which of these types of toxicity measures the risk from one-time exposure?

Acute systemic toxicity specifically refers to the adverse effects that result from a one-time or short-term exposure to a toxic substance, such as a chemical or herbicide. This type of toxicity evaluates how the body responds immediately or shortly after exposure and is crucial for understanding the risks associated with a single incident or brief contact with a harmful agent.

In the context of herbicide application, recognizing acute systemic toxicity is important because it allows applicators to understand the potential immediate effects of herbicides on human health or the environment after a single exposure event. This can inform safety measures and response strategies in case of accidental exposures.

Other types of toxicity mentioned have different exposure contexts, with chronic toxicity relating to long-term exposure and its effects, subacute toxicity often focusing on repeated exposures over a shorter time frame, and subchronic toxicity bridging longer durations but still designed to investigate effects from repeated exposure, though not chronic. Thus, the distinction is critical for assessing risk based on the specific duration and frequency of exposure.