Which signal word indicates moderate toxicity?

• A. Danger
• B. Caution
• C. Moderate
• D. Warning

Answer: (D)

Signal words on hazard labels convey how severe a chemical’s toxicity is. Among the standard words used, Danger signals the highest level of hazard, while Warning indicates a moderate level of hazard. The word Moderate isn’t used as a signal word on modern hazard labels, and Caution is generally reserved for lower-level or less immediate risks. So for a toxicity level that’s not extreme but still requires care, the appropriate label is Warning. This is the phrase you’d expect to see with statements like “Harmful if swallowed” or “Causes eye irritation,” which alert you to take precautions without the extreme measures associated with Danger.