According to NFPA 704, the most dangerous number associated with each hazard is what?

• A. The Identity of the Chemical
• B. Emergency Response Procedures
• C. The Physical State
• D. Potential Dangers

Answer: (D)

NFPA 704 conveys danger by three numeric ratings: health, flammability, and reactivity, each from 0 to 4. The number that matters most is the highest of those three ratings because it shows the most dangerous aspect of the substance and signals the level of precaution needed. This is what guides responders on how to handle the material safely.

The other elements listed—identity of the chemical, emergency response procedures, or its physical state—are not the hazard rating itself. They don’t capture how dangerous the substance could be in terms of health effects, fire risk, or reactivity. So the overall indication of “potential dangers” is tied to the highest hazard number, making that option the best fit.