What signal word is required for Category IV pesticides?

• A. There isn't one; it's the least toxic
• B. Danger
• C. Warning
• D. Caution

Answer: (A)

Signal words indicate the level of acute toxicity and the precautions needed when handling a pesticide. For Category IV pesticides, which are the least toxic, the label uses the word “Caution.” This communicates a lower hazard level and the corresponding, lighter precautions compared to higher-toxicity categories. The idea is that more toxic products carry stronger signal words—Danger or Warning—so they require more stringent protective measures. So the correct concept is that Category IV should display “Caution.” The option suggesting there isn’t a signal word doesn’t fit because even the least toxic products have a signal word, and the other choices correspond to higher hazard levels rather than Category IV.