What can indicate that a pesticide will likely run off during rainfall?

The indication that a pesticide is likely to run off during rainfall is closely linked to its solubility in water. When a pesticide is soluble in water, it can easily dissolve and be transported with runoff water during rainfall events. This means that if the pesticide is applied to the soil and then a rainstorm occurs, the water can carry the dissolved pesticide away from the target area, potentially leading to environmental contamination of nearby water sources.

Pesticides that are highly viscous may not easily wash away because their thick consistency can inhibit movement in water. Similarly, volatile pesticides tend to evaporate rather than run off, as they have a tendency to transition into gas form at lower temperatures. Pesticides with low absorption can also suggest that they do not strongly adhere to soil particles, but this characteristic alone does not guarantee that they will run off; other factors, such as solubility, play a more crucial role. Therefore, solubility is the most direct indicator of potential runoff during rainfall events.