The National Fire Protection Association
(NFPA) has developed a system to indicate
the health, flammability, and reactivity
hazards of chemicals. In addition, a special
precaution symbol may be used.
• The NFPA’s hazard labels are shaped like
diamonds. The top section reveals the
flammability of a substance. The left section
indicates a substance’s health hazards. The
right section tells how reactive a substance is
with other substances.
Special Hazard Information
• Numbers ranging from 0 to 4 are
recorded in each of the top three
diamonds to indicate how dangerous a
substance is. A four is the most
dangerous, while zero is the least
• The bottom section is for special
hazard information. It may be empty,
but some symbols that can appear in
this section are:
Reacts with water
Lasers being used
Electric Shock Warning
Reacts with oxygen to form
compounds such as oxides.
Why might this be dangerous?