In NFPA 704, what does the blue (left) section represent?

In NFPA 704, what does the blue (left) section represent?

• A. Health hazard rating.
• B. Flammability rating.
• C. Reactivity rating.
• D. Special hazards.

Answer: (D)

Blue on the left is the health hazard rating. In the NFPA 704 diamond, each color represents a different type of hazard, and the blue section specifically shows how dangerous a substance is to health if you’re exposed. The numbers run from 0 (no hazard) to 4 (severe hazard). The other colors cover the other hazards: red on top for flammability, yellow on the right for reactivity, and the white bottom for any special hazards (like oxidizers or water-reactive notes). So the blue left area is not about special hazards—that belongs to the white section.

Blue on the left is the health hazard rating. In the NFPA 704 diamond, each color represents a different type of hazard, and the blue section specifically shows how dangerous a substance is to health if you’re exposed. The numbers run from 0 (no hazard) to 4 (severe hazard). The other colors cover the other hazards: red on top for flammability, yellow on the right for reactivity, and the white bottom for any special hazards (like oxidizers or water-reactive notes). So the blue left area is not about special hazards—that belongs to the white section.