In NFPA 704, what does the blue section of the fire diamond indicate?

The blue section of the NFPA 704 fire diamond specifically indicates health hazards associated with the material in question. This system is designed to provide quick, easily interpretable information about the potential risks posed by hazardous materials, enabling firefighters and responders to assess the immediate dangers quickly.

In the context of the diamond, the blue section utilizes a numerical scale ranging from 0 to 4, where 0 represents no health hazard and 4 denotes a severe health risk. This allows responders to gauge the level of protective measures that may be necessary when dealing with a hazardous substance. Understanding this aspect is crucial for ensuring safety and effective response in emergency situations involving hazardous materials.