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Hazardous Materials Incidents

A chemical emergency occurs when a hazardous chemical has been released and the release has the potential for harming people's health. Chemical releases can be unintentional, as in the case of an industrial accident, or intentional, as in the case of a terrorist attack. 

Where Hazardous Chemicals Come From
Some chemicals that are hazardous have been developed by military organizations for use in warfare. Examples are nerve agents such as sarin and VX, mustards such as sulfur mustards and nitrogen mustards, and choking agents such as phosgene. It might be possible for terrorists to get these chemical warfare agents and use them to harm people. 

Many hazardous chemicals are used in industry (for example, chlorine, ammonia, and benzene). Others are found in nature (for example, poisonous plants). Some could be made from everyday items such as household cleaners. These types of hazardous chemicals also could be obtained and used to harm people, or they could be accidentally released. 

Types and Categories of Hazardous Chemicals
Scientists often categorize hazardous chemicals by the type of chemical or by the effects a chemical would have on people exposed to it. The categories/types used by the Centers for Disease Control and Prevention are as follows:
  • Biotoxins - poisons that come from plants or animals

  • Blister agents/vesicants - chemicals that severely blister the eyes, respiratory tract, and skin on contact

  • Blood agents - poisons that affect the body by being absorbed into the blood

  • Caustics (acids) - chemicals that burn or corrode people’s skin, eyes, and mucus membranes (lining of the nose, mouth, throat, and lungs) on contact

  • Choking/lung/pulmonary agents - chemicals that cause severe irritation or swelling of the respiratory tract (lining of the nose and throat, lungs)

  • Incapacitating agents - drugs that make people unable to think clearly or that cause an altered state of consciousness (possibly unconsciousness)

  • Long-acting anticoagulants - poisons that prevent blood from clotting properly, which can lead to uncontrolled bleeding

  • Metals - agents that consist of metallic poisons

  • Nerve agents - highly poisonous chemicals that work by preventing the nervous system from working properly

  • Organic solvents - agents that damage the tissues of living things by dissolving fats and oils

  • Riot control agents/tear gas - highly irritating agents normally used by law enforcement for crowd control or by individuals for protection (for example, mace)

  • Toxic alcohols - poisonous alcohols that can damage the heart, kidneys, and nervous system

  • Vomiting agents - chemicals that cause nausea and vomiting
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Last updated July 12, 2016