Chemicals Hazard Rating System

The National Fire Protection Association (NFPA) hazard system for chemical materials. The NFPA 704 Diamond indicates health, flammability, reactivity and special hazards for common chemicals.

RatingHealthFlammabilityReactivitySpecial Hazards
4 - SEVEREDeadly, even the slightest exposure would be life threateningFlash Point Below 73°F - Extremely flammable, volatile and explosiveMay Detonate - May explode at normal temperatures and pressuresRadiation, Acid, Alkali, Corrosive, Oxidizer, Use No Water
3 - SERIOUSExtreme Danger - Serious injury would result from exposureFlash Point Below 100°F - Flammable, volatile or explosive at normal temperatures and pressureExplosive - Capable of detonation or explosion by heat, shock or water
2 - MODERATEDangerous - Exposure would be hazardous to healthFlash Point Below 200°F - Moderately heated conditions may igniteUnstable - Violent chemical changes possible at normal temperatures or when mixed with water
1 - SLIGHTIrritation or minor injury would result from exposureFlash Point Above 200°F - Substance must be preheated to igniteNormally Stable - May become unstable at elevated temperatures or with water
0 - MINIMALNo significant hazard or health riskWill Not BurnStable - Remains stable with heat, pressure and water