The NFPA 704 diamond

The NFPA 704 Diamond ("NFPA Diamond" or "fire diamond") is a standard placard that identifies the level of chemical hazard at fixed locations, such as production facilities, warehouses, storage tanks, and storage sheds. It also is used on some transported containers.

The NFPA 704 diamond is divided into four colored quadrants. Each quadrant provides information about the materials inside:

• Blue represents health hazard.
• Red represents flammability.
• Yellow represents reactivity.
• White provides information about special precautions.

Within each quadrant is a number from 0 to 4 indicating the degree of risk associated with the material. The higher the number, the higher the risk. For some materials, the white quadrant contains symbols indicating special hazards. The meaning of each code number and symbol is shown in the table below.

If more than one chemical is present at a facility, the NFPA diamond indicates overall hazard at that location, not the hazard posed by a particular chemical. It shows the highest of each of the four hazards present. For example, it may be that one chemical poses the highest health hazard while another poses the highest fire hazard.

If there's no NFPA diamond at a facility, don't assume that there are no dangerous chemicals present. Sometimes, a diamond may be missing or displayed in a location where it isn't visible to responders.

Interpreting NFPA 704

numbers and symbols