Hazardous substances ignition

Hazardous substances present in the process are identified on the basis of their flammability, explosiveness and toxicity. The flammability of gases and vapours of flammable liquids is a great concern in the process industries. The result of an ignition can be a fire or an explosion or both. Accidental fires and explosions of flammable mixtures with air often follow the escape of combustible materials or inlet of air into process equipment. 

A chemical waste is considered hazardous if it exhibits one or more of the following characteristics ignitability, corrosivity, reactivity, and toxicity. Under the authority of the Resource Conservation and Recovery Act (RCRA) and the U.S. Environmental Protection Agency (EPA), a hazardous substance has one or more of the foregoing characteristics. 

The term hazardous substance refers to any raw materials, intermediate products, final products, spent wastes, accidental spills, leakages, and so on, that are hazardous to human health and the environment. Technically speaking, aU ignitable, corrosive, reactive (explosive), toxic, infectious, carcinogenic, and radioactive substances are hazardous [1-3]. 

The hazardous waste identification regulations that define the characteristics of toxicity, ignitability, corrosivity, reactivity, and the tests for these characteristics, differ from state to state. In addition, concentration limits may be set out by a state for selected persistent and bioaccumulative toxic substances that commonly occur in hazardous substances. For example, the California Hazardous Waste Control Act requires the California State Department of Health Services (CDHS) to develop and adopt by regulation criteria and guidelines for the identification of hazardous wastes and extremely hazardous wastes. 

There are many potential causes of explosions and fires at industrial sites handling hazardous substances (a) chemical reactions that produce explosion, fire, or heat (b) ignition of explosive or flammable chemicals (c) ignition of materials due to oxygen enrichment (d) agitation of shock- or friction-sensitive compounds and (e) sudden release of materials under pressure [21,29]. 

First, a waste (or any other material) may be hazardous due to its physical and chemical properties, rather than the presence of hazardous substances. For example, a material that is readily explosive or reactive (e.g., hydrogen gas, liquid sodium metal) clearly constitutes a hazard even though the constituent substances themselves may not be hazardous to human health. EPA has identified wastes as hazardous if they are ignitable, corrosive, or reactive. 

Hazardous substance Kind of substance or material, (e.g., corrosive, ignitable, explosive, or chemically reactive) that may pose a threat to human health and environment safety. Normally, the USEPA designates typical hazardous substance(s). 

Small gas flame ignitability test ( ) Classification test of the class II hazardous substances as per the Fire Services Law. 

CONSENSUS REPORTS lARC Cancer Review Group 2B IMEMDT 52,363,91 Human Inadequate Evidence IMEMDT 52,363,91. Reported in EPA TSCA Inventor). Cobalt and its compounds are on the Community Right-To-Know List. EPA Extremely Hazardous Substances List. OSHA PEL TWA 0.1 mg(Co)/m3 ACGIH TLV TWA 0.1 mg(Co)/m3 SAFETY PROFILE Poison by inhalation and intraperitoneal routes. Questionable carcinogen. Decomposes in air to form a product that ignites spontaneously in air. When heated to decomposition it emits acrid smoke and fumes. See also CARBONYLS and COBALT COMPOUNDS. 

Hazardous waste Waste regulated under RCRA that can pose a substantial or potential hazard to human health or the environment when improperly managed. Such wastes possess at least one of our characteristics (ignitability, corrosivity, reactivity, or toxicity) or appear on special EPA hazardous waste lists. The term is not interchangeable with hazardous substance or material. 

Organic peroxides are among the most hazardous substances handled in the chemical laboratory. They are generally low-power explosives that are sensitive to shock, sparks, or other accidental ignition. They are far more shock-sensitive than most primary explosives such as TNT. 

Hazardous waste is defined under the Resource Conservation and Recovery Act (RCRA) as a solid waste (or combination of solid wastes) which, because of its quantity, concentration, or physical, chemical, or infectious characteristics, may (1) cause or contribute to an increase in mortality or an increase in serious irreversible, or incapacitating illness or (2) pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of, or otherwise managed. In addition, under RCRA, EPA establishes four characteristics that will determine whether a substance is considered hazardous, including ignitability, corrosiveness, reactivity, and toxicity. Any solid waste that exhibits one or more of these characteristics is classified as a hazardous waste under RCRA and, in turn, as a hazardous substance mider Superfiind. 

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