October 2011 Safety Tip


The National Fire Protection Association (NFPA) has developed a rating system to provide fast information regarding the hazards of chemicals. The label is diamond-shaped, made up of four smaller diamonds, one each blue, red, yellow, and white. A number or special symbol is placed on the four diamonds. This month’s Safety Tip takes a look at the meaning of the colors, number, and symbols used on the NFPA diamond.

One glance at a NFPA diamond label can give you a wealth of information about the material. So what do those colors and numbers mean?

The blue diamond, on the left side of the label, conveys Health Hazard information for persons exposed to the material. The higher the number (on a scale of 0 to 4) the higher the hazard, as follows:
0 - No hazard.
1 - Can cause irritation if not treated.
2 - Can cause injury. Requires prompt treatment.
3 - Can cause serious injury despite medical treatment.
4 - Can cause death or major injury despite medical treatment

The red diamond, at the top of the label, conveys Flammability Hazard information. Again, the numbers 0 to 4 are used to rate the flammability hazard, as follows:
0 - Will not burn.
1 - Ignites after considerable preheating.
2 - Ignites if moderately heated.
3 - Can be ignited at all normal temperatures.
4 - Very flammable gases or very volatile flammable liquids

The yellow diamond, at the right side of the label, conveys Reactivity (or Stability) information. The numbers 0 to 4 are also used to rank reactivity hazards, as follows:
0 - Normally stable. Not reactive with water.
1 - Normally stable. Unstable at high temperature and pressure. Reacts with water.
2 - Normally unstable but will not detonate.
3 - Can detonate or explode but requires strong initiating force or heating under confinement.
4 - Readily detonates or explodes.

The white diamond, at the bottom of the label, conveys Special Hazard information. This information is conveyed by use of symbols which represent the special hazard. Two of the common symbols are shown here:
“W” denotes the material is water reactive
“OX” denotes an oxidizing agent

Taking a quick glance at the NFPA label provides a wealth of information. Follow the warnings on the NFPA label or any label affixed to a container of material. Remember, when you're working with hazardous materials, your safety depends on you.

(Adapted from Wes-Con fact sheet)