What is the primary factor in determining a pesticide's toxicity?

The primary factor in determining a pesticide's toxicity is the active ingredient. This component is responsible for the pesticide's mechanism of action and how it interacts with target pests. The active ingredient determines how the pesticide affects biological organisms, including humans, wildlife, and beneficial insects.

While the formulation, application method, and registration status play important roles in the overall effectiveness and safety of pesticide use, it is the active ingredient that fundamentally dictates the level of toxicity. For instance, some active ingredients may be highly toxic in small quantities, while others may require larger doses to achieve the same level of impact. Thus, understanding the specific active ingredient is crucial for assessing the potential risks associated with a pesticide.