Which signal word indicates that a pesticide is highly toxic?

The choice that indicates a pesticide is highly toxic is "Danger/Poison." This signal word is used on pesticide labels to alert users to the acute hazards associated with the product. It signifies that the pesticide poses a high risk of causing severe harm or even death upon exposure, which may include ingestion, inhalation, or dermal contact. The presence of "Poison" further emphasizes the extreme nature of the toxicity, requiring handlers to take stringent safety precautions.

In general, signal words serve to categorize the level of risk associated with pesticide use. Other signal words like "Caution" and "Warning" indicate lower levels of toxicity, with "Caution" signifying the least dangerous classification. "Warning" suggests a moderate level of toxicity, but neither conveys the high risk that "Danger/Poison" does. Therefore, the specific wording "Danger/Poison" is critical in understanding the potential hazards and necessary safety measures when handling highly toxic pesticides.