NFPA placard blue indicates which hazard?

• A. Instability
• B. Health Hazard
• C. Flammability
• D. Special Notice

Answer: (B)

NFPA 704 placards use a diamond divided into four colored sections to convey different hazards quickly. Each color points to a specific type of risk: blue for health, red for flammability, yellow for instability/reactivity, and white for special hazards or PPE notes. The blue section communicates how a substance may affect health if someone is exposed—higher numbers mean greater health risk and the need for stronger protection and exposure control. So, when you see blue, you’re looking at a health hazard. The other colors indicate other risks: red for how easily it catches fire, yellow for reactivity or instability, and white for any special precautions or symbols.