Which color diamond in NFPA 704 identifies hazards to human health?

Which color diamond in NFPA 704 identifies hazards to human health?

• A. Red
• B. Yellow
• C. White
• D. Blue

Answer: (D)

In NFPA 704 labeling, each color in the diamond communicates a different type of hazard. The blue section is dedicated to hazards to human health. The numbers inside that blue area (0–4) indicate how severe the health risk is, from no hazard (0) to severe or deadly risk (4). This helps responders quickly gauge the potential health impact of exposure and decide on protective actions and PPE. The other colors cover different hazards: red is flammability, yellow is stability/reactivity, and white is for special hazards (like oxidizers or water-reactive materials). So blue is the color that flags health-related hazards.

In NFPA 704 labeling, each color in the diamond communicates a different type of hazard. The blue section is dedicated to hazards to human health. The numbers inside that blue area (0–4) indicate how severe the health risk is, from no hazard (0) to severe or deadly risk (4). This helps responders quickly gauge the potential health impact of exposure and decide on protective actions and PPE. The other colors cover different hazards: red is flammability, yellow is stability/reactivity, and white is for special hazards (like oxidizers or water-reactive materials). So blue is the color that flags health-related hazards.