Definition Of Hazard Class Division

These areas are in north america united states and canada historically classified with the class division system.

Definition of hazard class division. Define hazard class 1 4. Gas vapor class i dust class ii fibers class iii. Class 2 gases three divisions 2 1 flammable gas gas at 20 degrees c 68 degrees f or less 101 3 kpa 14 7 psi of pressure is ignitable at 101 3 kpa 14 7 psi when in a mixture of 13 percent or less by volume with. The explosive effects are largely confined to the package and no projection of fragments of appreciable size or range is expected.

Although the description of divisions varies slightly by class in general their meaning is. The first step in classifying the hazardous location in either system is to determine the type of hazardous substance. The hazard class or division number must be displayed in the lower corner of a placard and is required for both primary and subsidiary hazard classes and divisions if applicable. A division 1 classification means that the substance in the class it is paired with has a high probability of producing an ignitable or explosive mixture due to it being present continuously intermittently or periodically.

Only a small hazard in the event of ignition or initiation during transport with any effects largely confined to the package. Areas with possible fire or explosion risks due to explosive atmospheres and or mixtures are called hazardous or classified locations or areas. In the united states the nec uses 3 different classifications. 173 2 hazardous materials classes and index to hazard class definitions.

Substances and articles which have a fire hazard and either a minor blast hazard or a minor projection hazard or both. Hazardous location classification guide. The hazard class of a hazardous material is indicated either by its class or division number its class name or by the letters orm d. Substances and articles which present no significant hazard.

Division 1 the hazardous compound is present during normal operation or is present during some frequent operations such as maintenance. Placards are used to identify the class or division of a material. Explosives that present a minor explosion hazard. The hazard class of dangerous goods commodities is indicated either by its class or division number or name.

The substance may also come from the equipment in the area under normal circumstances. The nfpa establishes area classifications based on classes divisions and zones that when combined delineate the hazardous conditions of a specific area.