The National Fire Protection Association 704 (NFPA 704) provides a recognized and understood standard for identifying specific hazards and their severity. It addresses the health, flammability, instability and related hazards that may be presented as short-term, acute exposures that are most likely to occur as a result of fire, spill or similar emergency.
The NFPA 704 system is applicable to industrial, commercial and institutional facilities that manufacture, process or store hazardous materials. The system is characterized by the diamond, “square-on-point” shape. It identities the degree of severity for the health, flammability and instability of hazards. Severity is indicated by a numerical rating that ranges from zero indicating a minimal hazard, to four indicating a severe hazard.
Hazard placards should be posted on the two exterior walls of a facility, access to a room or area or each principal means of access to an exterior storage area. These placards are a means for quick hazard information for first responders and should be visible in case of an emergency where the responders are likely to enter.
Health is arranged at the nine o’clock position and color-coded blue.
Flammability is arranged at the 12 o’clock position and color-coded red.
Instability is arranged at the three o’clock position and color-coded yellow.
Special hazards are located in the six o’clock position with a white color-coded background. The special hazards in use are W, which indicates unusual reactivity with water, and OX, which indicates that material is an oxidizer.