Office of Environmental Health and Safety

Student in Lab

National Fire Protection Association Labeling

NFPA uses a symbol system designed as a diamond-shaped label containing four differently colored squares. A number (0-4) or an abbreviation is added to each square indicating the order of hazard severity. The higher the number, the greater the hazard.

NFPA Labeling System

Red background = Flammability Yellow Background = Reactivity
4 - flash point < 73º F
3 - flash point < 100ºF
2 - flash point > 100ºF to < 200 ºF
1 - flash point > 200ºF
0 - will not burn
4 - Explosive at room temperature.
3 - Shock and heat may detonate
2 - Violent reaction with water
1 - Unsafe if heated, not violent
0 - Not reactive with water.
Blue Background = Health Hazard. White Background = Specific Hazard.
4 - Deadly
3 - Extreme danger
2 - Hazardous
1- Slightly Hazardous
0 - Normal material
Oxidizer : OX
Acid: ACID
Alkali: ALK
Corrosive: CORR
Use No Water: W

Visit the NFPA web site.