What are the main concerns for each physical hazard class?
| Hazard Class | General Description |
|---|---|
| Flammable gases Flammable Aerosols Flammable liquids Flammable solids | These four classes cover products that have the ability to ignite (catch fire) easily and the main hazards are fire or explosion |
| Oxidizing gases Oxidizing liquids Oxidizing solids | These three classes cover oxidizers, which may cause or intensify a fire or cause a fire or explosion |
| Gases under pressure | This class includes compressed gases, liquefied gases, dissolved gases and refrigerated liquefied gases. Compressed gases, liquefied gases and dissolved gases are hazardous because of the high pressure inside the cylinder or container. The cylinder or container may explode if heated Refrigerated liquefied gases are very cold and can cause severe cold (cryogenic) burns or injury. |
| Self-reactive substances and mixtures | These products may react on their own to cause a fire or explosion, or may cause a fire or explosion if heated. |
| Pyrophoric liquids Pyrophoric solids Pyrophoric gases | These production can catch fire very quickly (spontaneously) if exposed to air. |
| Self-heating substances and mixtures | These products may catch fire if exposed to air. These products differ from pyrophoric liquids or solids in that they will ignite only after a longer period of time or when in larger amounts. |
| Substances and mixtures which, in contact with water, emit flammable gasses | As the class name suggests, these products react with water to release flammable gases. In some cases, the flammable gases may ignite very quickly (spontaneously). |
| Organic peroxides | These products may cause a fire or explosion if heated. |
| Corrosive to metals | These products may be corrosive (chemically damage or destroy) to metals. |
| Combustible dust | This class is used to warn of products that are finely divided solid particles. If dispersed in air, the particles may catch fire or explode if ignited. |
| Simple asphyxiants | These products are gases that may displace oxygen in air and cause rapid suffocation |
| Physical hazards not otherwise classified | This class is meant to cover any physical hazards that are not covered in any other physical hazard class. These hazards must have the characteristic of occurring by chemical reaction and result in the serious injury or death of a person at the time the reaction occurs. If a product is classified in this class, the hazard statement on the label and SDS will describe the nature of the hazard. |