| Health (Blue) |
|
| 0 |
Poses no health hazard, no precautions necessary (e.g., water) |
| 1 |
Exposure would cause irritation with only minor residual injury (e.g., acetone) |
| 2 |
Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury (e.g., ethyl ether) |
| 3 |
Short exposure could cause serious temporary or moderate residual injury (e.g., chlorine gas) |
| 4 |
Very short exposure could cause death or major residual injury (e.g., hydrogen cyanide, phosphine, carbon monoxide) |
| Flammability (Red) |
|
| 0 |
Will not burn (e.g., argon) |
| 1 |
Must be heated before ignition can occur (e.g., mineral oil). Flash point over 93°C (200°F) |
| 2 |
Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur (e.g., diesel fuel). Flash point between 38°C (100°F) and 93°C (200°F) |
| 3 |
Liquids and solids that can be ignited under almost all ambient temperature conditions (e.g., gasoline). Liquids having a Flash point below 23°C (73°F) and having a Boiling point at or above 38°C (100°F) or having a Flash point between 23°C (73°F) and 38°C (100°F) |
| 4 |
Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily (e.g., propane, hydrogen). Flash point below 23°C (73°F) |
| Instability/Reactivity (Yellow) |
|
| 0 |
Normally stable, even under fire exposure conditions, and is not reactive with water (e.g. helium) |
| 1 |
Normally stable, but can become unstable at elevated temperatures and pressures (e.g. propene) |
| 2 |
Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water (e.g., phosphorus, potassium, sodium) |
| 3 |
Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked (e.g. ammonium nitrate) |
| 4 |
Readily capable of detonation or explosive decomposition at normal temperatures and pressures (e.g., nitroglycerine,Trinitrotoluene) |
| Special (White) |
|
| The white "special notice" area can contain several symbols. The following symbols are defined by the NFPA 704 standard. |
|
| OX |
Oxidizer (e.g., potassium perchlorate, ammonium nitrate, hydrogen peroxide) |
| W |
Reacts with water in an unusual or dangerous manner (e.g., cesium, sodium, sulfuric acid) |
|
Non 704 Standard codes which may be used due to local regulation |
| Cor |
Corrosive , strong acid or base |
| Acid |
Strong Acid |
| Alk |
Strong base |
| Bio |
Biological hazard, may also be the bio hazard image |
| Poi |
Poisonous |
| Cyl or Cryo |
Cryogenic |
