| Health Hazard (blue) |
Definition |
| 4 |
Materials which on very short exposure could cause death or major residual injury even though prompt medical treatment were given |
| 3 |
Materials which on short exposure could cause serious temporary or residual injury even though prompt medical treatment were given. |
| 2 |
Materials which on intense or continued exposure could cause temporary incapacitation or possible residual injury unless prompt medical treatment is given. |
| 1 |
Materials which on exposure would cause irritation but only minor residual injury even if no treatment is given. |
| 0 |
Materials which on exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. |
| Flammability (red) |
|
| 4 |
Materials which will rapidly or completely vaporize at atmospheric pressure and normal ambient temperature, or which are readily dispersed in air and which will burn readily. |
| 3 |
Liquids and solids that can be ignited under almost all ambient temperature conditions. |
| 2 |
Materials that must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur. |
| 1 |
Materials that must be preheated before ignition can occur. |
| 0 |
Materials that will not burn. |
| Reactivity (yellow) |
|
| 4 |
Materials which in themselves are readily capable of detonation or explosive decomposition or reaction at normal temperatures and pressures. |
| 3 |
Materials which in themselves are capable of detonation or explosive reaction but require a strong initiating source or which must be heated under confinement before initiation or which react explosively with water. |
| 2 |
Materials which in themselves are normally unstable and readily undergo violent chemical change but do not detonate. Also materials which may react violently with water or which may form potentially explosive mixtures with water. |
| 1 |
Materials which in themselves are normally stable, but which can become unstable at elevated temperatures and pressures or which may react with water with some release of energy but not violently. |
| 0 |
Materials which in themselves are normally stable, even under fire exposure conditions, and which are not reactive with water. |
| Other (white) |
|
| W |
Materials which react so violently with water that a possible hazard results when they come in contact with water, as in a fire situation. Similar to Reactivity Classification 2. |
| Oxy |
Oxidizing material; any solid or liquid that readily yields oxygen or other oxidizing gas, or that readily reacts to oxidize combustible materials. |
