What do the colors represent on the NFPA diamond?

The NFPA diamond is one of the most iconic safety symbols in many different industries. Anywhere that works with potentially dangerous chemicals or materials will have seen this diamond. Even those who don’t work in these types of industries will likely have seen them on the backs of semi-trucks that are transporting dangerous solutions. The colors that are used in the NFPA diamond have a specific meaning and can make it easier for people to quickly identify what type of hazard is present for the chemicals that are being labeled.

Red NFPA Diamond

The top section of the NFPA diamond is going to be red. The more flammable the substance is, the higher the number that is in the diamond will be with a zero being not flammable at all, and 4 being the highest level of flammability.

Blue NFPA Diamond

On the left side of the NFPA diamond when looking at it will be the color blue. This is used to indicate that the chemical being labeled has some type of health hazard. If it has a zero in the blue diamond then there is no health hazards at all. As the number goes up to four the severity of the hazard continues to escalate.

Yellow NFPA Diamond

On the right side of the diamond when looking at it you will see a yellow diamond. This is used to indicate the instability of a chemical that is being labeled. This indicates that the chemicals may be extremely unstable if they have a 4 and are completely stable when there is a zero.

White NFPA Diamond

At the bottom of the NFPA diamond you will find a white area, which is used for special hazards. Rather than using numbers in this section you will see a letter or symbol. The most common of these is a W, which is used to indicate that the chemical has an unusual reaction when exposed to water. This is critical information for firefighters should they be responding to an emergency. Another common option in this section is OX, which signals those who see it that the substance is an oxidizer.


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