Classes of Hazardous Chemicals Chemicals can be divided into several different hazard classes. The hazard class provides information to help determine how a chemical can be safely stored and handled. Each chemical container, whether supplied by a chemical manufacturer or produced in the laboratory, must have a label that clearly identifies the chemical constituents. In addition to a specific chemical label, more comprehensive hazard information can be found by referencing the SDS for that chemical. The OSHA Laboratory Standard defines a hazardous chemical as any element, chemical compound, or mixture of elements and/or compounds which is a physical or health hazard. This definition of a hazardous chemical and the GHS primary classes of chemicals are briefly discussed below. Physical Hazards A chemical is a physical hazard if there is scientifically valid evidence that it is flammable, combustible, compressed gas, explosive, organic peroxide, oxidizer, pyrophoric, self-heating, self-reactive, or water-reactive. Each physical hazard is briefly defined below. Refer to Appendix B (section B.1) for detailed information on each physical hazard. Explosives: A liquid or solid which is in itself capable by chemical reaction of producing gas at such a temperature and pressure and at such a speed as to cause damage to the surroundings. Flammable Liquids: Materials which under standard conditions can generate sufficient vapor to cause a fire in the presence of an ignition source and have a flash point no greater than 93 °C (200 °F). Flammable Solid: A solid which is readily combustible, or may cause or contribute to a fire through friction. Gases under Pressure: Gases which are contained in a receptacle at a pressure not less than 280 kPA at 20 °C or as a refrigerated liquid. Organic Peroxide: A liquid or solid which contains the bivalent -0-0- structure and may be considered a derivative of hydrogen peroxide, where one or both of the hydrogen atoms have been replaced by organic radicals. Oxidizer: A liquid or solid, while in itself is not necessarily combustible, may generally by yielding oxygen, cause or contribute to the combustion of other material. Pyrophoric Substance (also called Spontaneously Combustible): A liquid or solid that even in small quantities and without an external ignition source can ignite after coming in contact with the air.
Classes of Hazardous Chemicals Chemicals can be divided into several different hazard classes. The hazard class provides information to help determine how a chemical can be safely stored and handled. Each chemical container, whether supplied by a chemical manufacturer or produced in the laboratory, must have a label that clearly identifies the chemical constituents. In addition to a specific chemical label, more comprehensive hazard information can be found by referencing the SDS for that chemical. The OSHA Laboratory Standard defines a hazardous chemical as any element, chemical compound, or mixture of elements and/or compounds which is a physical or health hazard. This definition of a hazardous chemical and the GHS primary classes of chemicals are briefly discussed below. Physical Hazards A chemical is a physical hazard if there is scientifically valid evidence that it is flammable, combustible, compressed gas, explosive, organic peroxide, oxidizer, pyrophoric, self-heating, self-reactive, or water-reactive. Each physical hazard is briefly defined below. Refer to Appendix B (section B.1) for detailed information on each physical hazard. Explosives: A liquid or solid which is in itself capable by chemical reaction of producing gas at such a temperature and pressure and at such a speed as to cause damage to the surroundings. Flammable Liquids: Materials which under standard conditions can generate sufficient vapor to cause a fire in the presence of an ignition source and have a flash point no greater than 93 °C (200 °F). Flammable Solid: A solid which is readily combustible, or may cause or contribute to a fire through friction. Gases under Pressure: Gases which are contained in a receptacle at a pressure not less than 280 kPA at 20 °C or as a refrigerated liquid. Organic Peroxide: A liquid or solid which contains the bivalent -0-0- structure and may be considered a derivative of hydrogen peroxide, where one or both of the hydrogen atoms have been replaced by organic radicals. Oxidizer: A liquid or solid, while in itself is not necessarily combustible, may generally by yielding oxygen, cause or contribute to the combustion of other material. Pyrophoric Substance (also called Spontaneously Combustible): A liquid or solid that even in small quantities and without an external ignition source can ignite after coming in contact with the air.