This system of identifying hazards associated with various materials was developed primarily for fire protection and emergency personnel but can be useful to anyone who needs to handle potentially hazardous material. As stated in NFPA 704, "This standard provides a simple system of readily recognizable and easily understood markings, which will give at a glance a general idea of the inherent hazards of any material and the order of severity of these hazards as they relate to fire prevention, exposure, and control".
Click on an area of the image below for more specific information,
or scroll down the page for some general information.
Health (Blue)
| 4 | Danger | May be fatal on short exposure. Specialized protective equipment required |
| 3 | Warning | Corrosive or toxic. Avoid skin contact or inhalation |
| 2 | Warning | May be harmful if inhaled or absorbed |
| 1 | Caution | May be irritating |
| 0 | No unusual hazard |
Flammability (Red)
| 4 | Danger | Flammable gas or extremely flammable liquid |
| 3 | Warning | Flammable liquid flash point below 100° F |
| 2 | Caution | Combustible liquid flash point of 100° to 200° F |
| 1 | Combustible if heated | |
| 0 | Not combustible |
Reactivity (Yellow)
| 4 | Danger | Explosive material at room temperature |
| 3 | Danger | May be explosive if shocked, heated under confinement or mixed with water |
| 2 | Warning | Unstable or may react violently if mixed with water |
| 1 | Caution | May react if heated or mixed with water but not violently |
| 0 | Stable | Not reactive when mixed with water |
Special Notice Key (White)
| W | Water Reactive |
| OX | Oxidizing Agent |
Flammable!
Explosive!
Corrosive!
Poison!
Home Page