Hazardous Materials Classification – NFPA 704 Basics

Communicating the potential dangers of chemicals to your employees is crucial in maintaining the safety of your environment and is required by OSHA. Hazardous Material labels are known as “right to know” labels and quickly communicate information about health and fire hazards, reactivity, and other personal protective equipment that needs to be worn when handling said materials.

One type of label commonly found is the “fire diamond,” a standard maintained by the National Fire Protection Association.



A typical NFPA label, used to identify and classify hazardous materials. Formally known as “NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response.”


In this example, the label is split into four color-coded quadrants that are represented by a number scale that communicates the severity of the risk. Blue represents a health hazard which ranges from normal material to deadly, red represents a fire hazard which ranges from inflammable to a flash point below 73°F, yellow represents reactivity ranging from stable to may detonate, and white is for specific miscellaneous hazards.

For example, the label below would identify a material that is life-threatening, ignites under most normal temperature conditions, can undergo violent chemical change under certain conditions, and is corrosive.


nfpa specific example

How to use the NPFA “fire diamond” to identify a hazardous material.


The hazard code COR, for corrosive, is not part of the NFPA 704 standard. Codes for acid, radioactivity, biological hazards and poisons (ACID, RAD, BIO and POI respectively) are non-standard as well, but each are used occasionally in an unofficial manner.

Codes that do fall within the NFPA 704 standard are OX (for oxidizer, a material that allows chemicals to burn without an air supply), ₩ (a material that reacts dangerously with water), and SA (an asphyxiant gas).

Simply write the appropriate numbers and code onto the label and stick it on or near the relevant material to quickly and easily communicate the necessary precautions.

This quick step will go a long to way to keeping yourself and your employees safe on the factory floor.


Share This:

Posted in:

Leave a Reply

Your email address will not be published. Required fields are marked *