NFPA 704, titled theStandard System for the Identification of the Hazards of Materials for Emergency Response, is the definitive publication for the labeling of hazardous substance containers and facilities to protect first responders. It defines the widely recognized"NFPA Diamond"(or "Fire Diamond"), a square-on-point placard that provides an immediate, visual summary of the health, flammability, and instability hazards of a material, as well as any special hazards (such as water reactivity or oxidizing properties).

The NFPA 704 system is specifically designed forFirst Responders(Fire, Police, EMS) who arrive at a scene and need to make rapid, life-safety decisions without having immediate access to a full Safety Data Sheet (SDS). The system uses a rating scale from 0 (minimal hazard) to 4 (severe hazard):

Blue (Health):Indicates the level of toxicity or injury potential.

Red (Flammability):Indicates the temperature at which the material will ignite.

Yellow (Instability/Reactivity):Indicates how prone the material is to chemical change or explosion.

White (Special):Uses symbols likeW(water reactive) orOX(oxidizer).

In theCEDPcurriculum, NFPA 704 is emphasized as the first step inScene Size-Up. When a responder sees a "4" in the Blue or Red sectors, they know they must use the highest level of PPE (Level A) and maintain a significant isolation distance. NFPA 221 (Option A) deals with High Challenge Fire Walls, and NFPA 450 (Option B) is a guide for Emergency Medical Services Systems. NFPA 704 remains the global standard for on-site hazard communication, ensuring that those who enter a dangerous environment can "read the risk" at a glance and adjust their tactics accordingly to save lives while protecting themselves.