Which signal word must be present on the label for pesticides identified as "Slightly toxic"?

The signal word that must be present on the label for pesticides identified as "Slightly toxic" is "Caution!" This classification is part of a system used to indicate the level of toxicity of a pesticide product to humans and other organisms.

"Caution!" indicates that the substance has a relatively low level of toxicity, and while it may still pose some risk, it is generally considered less hazardous compared to products with stronger signal words. The presence of "Caution!" serves as a warning to users to handle the product carefully but does not suggest an immediate or severe risk of harm, which aligns with the characteristics of slightly toxic materials. Understanding these labels is crucial for safe application and handling of pesticides, ensuring that users are aware of the potential risks and take appropriate precautions.

The other signal words—such as "Warning!" and "Danger!"—indicate higher levels of toxicity and represent a greater potential risk. "Notice!" is typically not used as a signal word in the context of toxicity but may be used to convey additional information on the label.