National Fire Protection Association Hazard Ratings Interpretation:
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Interpretation of NFPA Hazard Rating Indices | ||
Health (Blue) | ||
| 4 | Danger | May be fatal on short exposure. Specialized protective equipment required |
| 3 | Warning | Corrosive or toxic. Avoid skin contact or inhalation - can cause serious injury |
| 2 | Warning | May be harmful if inhaled or absorbed |
| 1 | Caution | May be irritating |
| 0 | -- -- -- -- | No unusual hazard under fire conditions |
Flammability (Red) | ||
| 4 | Danger | Readily flammable gas or easily vaporized and extremely flammable liquid |
| 3 | Warning | Liquid or solid that will ignite under most ambient conditions. |
| 2 | Caution | Liquid or solid that is combustible if moderately preheated or exposed to high temperature |
| 1 | -- -- -- -- | Combustible if heated significantly |
| 0 | -- -- -- -- | Not combustible |
Instability or Reactivity (Yellow) | ||
| 4 | Danger | Will readily detonate at normal ambient temperature and pressure conditions |
| 3 | Danger | May be explosive if shocked, heated under confinement or mixed with water |
| 2 | Warning | Unstable (may violently decompose but not detonate) 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 Fire-related Notices (White) | ||
| W | Water Reactive - Substance poses a potential hazard if water is used for fire fighting | |
| OX | Oxidizing Agent - Substance may increase the rate of combustion of other materials | |