Which method measures the harm caused by a single, one-time exposure event?

Acute toxicity refers to the harmful effects that result from a single, one-time exposure to a substance, such as a herbicide. This type of toxicity is typically measured by observing the immediate effects that occur shortly after exposure, often within a few hours to a few days. Acute toxicity studies help determine the potential risks associated with short-term exposure to chemicals, which can be critical for assessing safety in both human and environmental contexts.

In contrast, chronic toxicity involves repeated or long-term exposure to a substance, assessing the effects that develop over an extended period. Systemic toxicity concerns the overall impact on the entire organism, typically indicating a broader range of responses than just the acute effects. Local toxicity specifically pertains to adverse effects that occur at the site of exposure rather than systemic harm throughout the organism. Understanding these distinctions is essential for effectively evaluating the consequences of herbicide applications and ensuring safe practices.