Hazardous materials (abbreviated as HAZMAT or hazmat) have a total life cycle that begins at its birth and continues till an effective grave or permanent solution is found for disposal of it. Any time a hazmat is moved or transported, the risk of exposure is increased. It may manifest its danger during industrial mishaps, fires, explosions, or spills.
Hazmats, hazardous goods, or hazardous wastes (HWs) are solids, liquids, or gases that can harm people, other living organisms, property, or the environment. They are usually subject to chemical regulations. In the United States, United Kingdom, and Canada, dangerous goods are more commonly known as hazmats. Hazmat teams are personnel specially trained to handle dangerous goods, which include materials that are radioactive, flammable, explosive, corrosive, oxidizing, asphyxiating, biohazardous, toxic, pathogenic, or allergenic. Also included are physical conditions such as compressed gases and liquids or hot materials, including all goods that contain such materials or chemicals or may have other characteristics that render them hazardous in specific circumstances.
In the United States, dangerous goods are often indicated by diamond-shaped signage on the item, its container, or the building where it is stored. The color of each diamond indicates its hazard; e.g., flammable is indicated with red, because fire and heat are generally of red color, and explosive is indicated with orange, because mixing red (flammable) with yellow (oxidizing agent) creates orange.
Laws and regulations on the use and handling of hazmats may differ depending on the activity and status of the material. For example, one set of requirements may apply to its use in the workplace, while a different set of requirements may apply to spill response, sale for consumer use, or transportation. Most countries regulate some aspect of hazmats.
The most widely applied regulatory scheme is that for the transportation of dangerous goods.
The Globally Harmonized System of Classification and Labeling of Chemicals (GHS) is an internationally agreed-upon system set to replace the various classification and labeling standards used in different countries. GHS will use consistent criteria for classification and labeling on a global level.
Dangerous goods are divided into nine classes (in addition to several subcategories) on the basis of the specific chemical characteristics producing the risk. These nine classes are as follows:
- • Class 1—explosives
- • Class 2—gases
- • Class 3—flammable liquids
- • Class 4—flammable solids
- • Class 5—oxidizing agents and organic peroxides
- • Class 6—toxic and infectious substances
- • Class 7—radioactive substances
- • Class 8—corrosive substances
- • Class 9—miscellaneous (asbestos, dry ice, etc.)