FLAMABILITY
0 - material will not burn1 - material must be preheated to burn
2 - material must be preheated or exposed to relatively high ambient temperature to ignite3 - material can be ignited under almost all ambient temperatures
4 - material will rapidly or completely vaporize readily at STP or will burn readily when dispersed in air
REACTIVITY
0 - material is normally stable and is not reactive with water
1 - material is normally stable, but may become unstable at elevated temperatures or may react with water2 - material is normally unstable and readily undergoes violent chemical change but does not detonate. May react violently with water or may form potentially explosive mixtures with water
3 - material is capable of detonation or explosive reaction but requires a strong initiating source or may react explosively with water
4 - material is readily capable of detonation or explosive decomposition or reaction at standard temperature and pressure (room pressure, 0 Celsius)
TOXICITY
0 - Exposure to materials under fire conditions offer no special health hazard1 - Exposure to material can cause short term irritation or minor residual injury if untreated
2 - Intense or continued exposure to material can cause temporary incapacitation or possible residual injury unless prompt medical attention is given
3 - Short exposure to material can cause serious temporary or residual injury even if prompt medical attention is given
4 - Very short exposure to material can cause death or major residual injury even if prompt medical attention is given
OTHER HAZARD CODES
1. OXY - an oxidizing material2. Corrosive - a strong acid or base
3. Radioactive material
4. Hazardous material when in contact with water