A number 4 in the blue quadrant of the National Fire Protection Association 704 system indicates what level of risk?

In the National Fire Protection Association (NFPA) 704 system, a number 4 in the blue quadrant specifically represents "severe" health risks. The NFPA 704 system uses a diamond shape divided into four quadrants to indicate the hazards posed by materials. Each quadrant represents a different type of hazard: health, flammability, reactivity, and specific hazards.

For the blue quadrant, the numeric scale ranges from 0 to 4, with higher numbers indicating greater risk. A 4 signifies that exposure to the material could result in serious health effects or even fatal outcomes. This is critical for emergency responders as it guides them in assessing the level of precautions needed when dealing with hazardous materials.

Understanding these risk levels is essential for firefighters and first responders to ensure their safety and the safety of the community when responding to incidents involving hazardous substances.