Hazardous waste

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Hazardous waste

Any solid, liquid, or gaseous waste materials that, if improperly managed or disposed of, may pose substantial hazards to human health and the environment. Every industrial country in the world has had problems with managing hazardous wastes. Improper disposal of these waste streams in the past has created a need for very expensive cleanup operations. Efforts are under way internationally to remedy old problems caused by hazardous waste and to prevent the occurrence of other problems in the future.

A waste is considered hazardous if it exhibits one or more of the following characteristics: ignitability, corrosivity, reactivity, and toxicity. Ignitable wastes can create fires under certain conditions; examples include liquids, such as solvents, that readily catch fire, and friction-sensitive substances. Corrosive wastes include those that are acidic and those that are capable of corroding metal (such as tanks, containers, drums, and barrels). Reactive wastes are unstable under normal conditions. They can create explosions, toxic fumes, gases, or vapors when mixed with water. Toxic wastes are harmful or fatal when ingested or absorbed. When they are disposed of on land, contaminated liquid may drain (leach) from the waste and pollute groundwater.

Hazardous wastes may arise as by-products of industrial processes. They may also be generated by households when commercial products are discarded. These include drain openers, oven cleaners, wood and metal cleaners and polishes, pharmaceuticals, oil and fuel additives, grease and rust solvents, herbicides and pesticides, and paint thinners.

The predominant waste streams generated by industries in the United States are corrosive wastes, spent acids, and alkaline materials used in the chemical, metal-finishing, and petroleum-refining industries. Many of these waste streams contain heavy metals, rendering them toxic. Solvent wastes are generated in large volumes both by manufacturing industries and by a wide range of equipment maintenance industries that generate spent cleaning and degreasing solutions. Reactive wastes come primarily from the chemical industries and the metal-finishing industries. The chemical and primary-metals industries are the major sources of hazardous wastes.

There is a growing acceptance throughout the world of the desirability of using waste management hierarchies for solutions to problems of hazardous waste. A typical sequence involves source reduction, recycling, treatment, and disposal. Source reduction comprises the reduction or elimination of hazardous waste at the source, usually within a process. Recycling is the use or reuse of hazardous waste as an effective substitute for a commercial product or as an ingredient or feedstock in an industrial process.

Treatment is any method, technique, or process that changes the physical, chemical, or biological character of any hazardous waste so as to neutralize such waste; to recover energy or material resources from the waste; or to render such waste nonhazardous, less hazardous, safer to manage, amenable for recovery, amenable for storage, or reduced in volume. Disposal is the discharge, deposit, injection, dumping, spilling, leaking, or placing of hazardous waste into or on any land or body of water so that the waste or any constituents may enter the air or be discharged into any waters, including groundwater.

There are various alternative waste treatment technologies, for example, physical treatment, chemical treatment, biological treatment, incineration, and solidification or stabilization treatment. These processes are used to recycle and reuse waste materials, reduce the volume and toxicity of a waste stream, or produce a final residual material that is suitable for disposal. The selection of the most effective technology depends upon the wastes being treated.

There are abandoned disposal sites in many countries where hazardous waste has been disposed of improperly in the past and where cleanup operations are needed to restore the sites to their original state. Cleaning up such sites involves isolating and containing contaminated material, removal and redeposit of contaminated sediments, and in-place and direct treatment of the hazardous wastes involved. As the state of the art for remedial technology improves, there is a clear preference for processes that result in the permanent destruction of contaminants rather than the removal and storage of the contaminating materials.

Hazardous waste

By-products of society with physical, chemical, or infectious characteristics that pose hazards to the environment and human health when improperly handled, specifically characterized by one or more of the following properties: ignitable, corrosive, reactive, or toxic.
References in periodicals archive ?
The proposal, when finalized, will affect the approximately 3,000 hazardous waste import shipments and 49,000 hazardous waste export shipments that largely occur within North America.
4 million metric tons of hazardous waste every year, according to estimates from the Indian Ministry of Environment and Forests (MEF).
He said alternative methods of treating and disposing of hazardous wastes already exist and are in use in many European states.
The EPA's position is that, if at any point in the processing of these materials hazardous waste is generated, then the processor is responsible for the safe disposition of these elements.
The company also pleaded guilty to three federal felony violations of hazardous waste handling and was fined $1.
Companies that store hazardous substances must keep track of the products that can no longer be used for their intended purpose and become hazardous wastes.
Hazardous waste removal can cost two to three dollars a pound.
The Court noted that there was no challenge to the state's purposes of limiting hazardous waste disposal to protect the environment and health of its citizens, but concluded that the state could have used nondiscriminatory means to accomplish these goals.
In 1997, a fire in a hazardous waste storage tank at Keystone Cement forced the evacuation of 1,600 residents of Bath, Pa.
Stored hazardous wastes at the facility without obtaining a permit or complying with conditions applicable to hazardous waste generators.
The main treaty that regulates hazardous waste trades today is the Basel Convention on the Control of Transboundary Movement of Hazardous Wastes and Their Disposal.

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