What Is NFPA 704 or the Fire Diamond

You probably have seen NFPA 704 or the fire diamond on chemical containers. The National Fire Protection Association (NFPA) in the United States uses a standard called NFPA 704 as a chemical hazard label. NFPA 704 sometimes is called a fire diamond because the diamond-shaped sign indicates flammability of a substance and also communicates essential information about how emergency response teams should deal with a material if there is a spill, fire or other accident. Understanding the Fire Diamond There are four colored sections on the diamond. Each section is labeled with a number from 0-4 to indicate the level of hazard. On this scale, 0 indicates no hazard while 4 means severe hazard. The red section indicates flammability. The blue section indicates a  health risk. Yellow indicates reactivity or explosivity. The white is section is used to describe any special hazards. Hazard Symbols on NFPA 704 Symbol and Number Meaning Example Blue - 0 Does not pose a health hazard. No precautions are necessary. water Blue - 1 Exposure may cause irritation and minor residual injury. acetone Blue - 2 Intense or continued non-chronic exposure may result in incapacitation or residual injury. ethyl ether Blue - 3 Brief exposure may cause serious temporary or moderate residual injury. chlorine gas Blue - 4 Very brief exposure may cause death or major residual injury. sarin, carbon monoxide Red - 0 Will not burn. carbon dioxide Red - 1 Must be heated in order to ignite. Flashpoint exceeds 90C or 200F mineral oil Red - 2 Moderate heat or relatively high ambient temperature is required for ignition. Flashpoint between 38C or 100F and 93C or 200F diesel fuel Red - 3 Liquids or solids that readily ignite at most ambient temperature conditions. Liquids have a flash point below 23C (73F) and the boiling point at or above 38C (100F) or flash point between 23C (73F) and 38C (100F) gasoline Red - 4 Rapidly or completely vaporizes at normal temperature and pressure or readily disperses in air and readily burns. Flashpoint below 23C (73F) hydrogen, propane Yellow - 0 Normally stable even when exposed to fire; not reactive with water. helium Yellow - 1 Normally stable, but may become unstable elevated temperature and pressure. propene Yellow - 2 Changes violently at elevated temperature and pressure or reacts violently with water or forms explosive mixtures with water. sodium, phosphorus Yellow - 3 May detonate or undergo explosive decomposition under the action of a strong initiator or reacts explosively with water or detonates under severe shock. ammonium nitrate, chlorine trifluoride Yellow - 4 Readily undergoes explosive decomposition or detonates at normal temperature and pressure. TNT, nitroglycerine White - OX oxidizer hydrogen peroxide, ammonium nitrate White - W Reacts with water in a dangerous or unusual way. sulfuric acid, sodium White - SA simple asphyxiant gas Only: nitrogen, helium, neon, argon, krypton, xenon