Hazardous waste

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This article describes hazardous waste as a substance; for the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal see Basel Convention

Hazardous waste is waste that poses substantial or potential threats to public health or the environment and generally exhibits one or more of these characteristics:

• flammable
• ignitable
• oxidizing
• corrosivity
• toxic

Hazardous wastes can be liquids, solids, contained gases, or sludges. They can be the by-products of manufacturing processes or simply discarded commercial products, like cleaning fluids or pesticides.

Generally, environmental toxicity is quantified through the use of the Toxicity Characteristic Leachate Procedure or the TCLP test (Method 1311), as required by the Environmental Protection Agency and Environment Canada.

Contents 1 Hazardous Wastes in the United States 1.1 Listed Wastes 1.2 Characteristic Wastes 2 See also 3 External links

[edit] Hazardous Wastes in the United States

In the United States, hazardous wastes may also be "listed" by the EPA. Listed hazardous wastes are generated by specific industries and processes and are considered hazardous waste irrespective of sample results. Examples include waste from iron and steel manufacturing and certain electroplating sludges.

Many types of businesses generate hazardous waste. Some are small companies that may be located in a community. For example, dry cleaners, automobile repair shops, hospitals, exterminators, and photo processing centers all generate hazardous waste. Some hazardous waste generators are larger companies like chemical manufacturers, electroplating companies, and oil refineries.

A US facility that treats, stores or disposes of hazardous waste must obtain a permit for doing so under the Resource Conservation and Recovery Act. Generators of and transporters of hazardous waste must meet specific requirements for handling, managing, and tracking waste. Through the RCRA, Congress directed the EPA to create regulations to manage hazardous waste. Under this mandate, the EPA developed strict requirements for all aspects of hazardous waste management including the treatment, storage, and disposal of hazardous waste. In addition to these federal requirements, states may develop more stringent requirements or requirements that are broader in scope than the federal regulations.

In regulatory terms, a Resource Conservation and Recovery Act (RCRA) hazardous waste is a waste that appears on one of the four hazardous wastes lists (F-list, K-list, P-list, or U-list), or exhibits at least one of four characteristics—ignitability, corrosivity, reactivity, or toxicity. Through the State Authorization rulemaking process, the EPA delegates the primary responsibility of implementing the RCRA hazardous waste program to individual states in lieu of the EPA. The State Authorization Tracking System (StATS) provides the authorization status for all states.
Some wastes that meet the RCRA definitions of solid and hazardous wastes are specifically excluded or exempted from the hazardous waste regulations (e.g., some oil and gas exploration and mining wastes and some hazardous wastes that can be recycled).

[edit] Listed Wastes

Hazardous wastes are incorporated into lists published by the Environmental Protection Agency. These lists are organized into three categories:

• The F-list (non-specific source wastes). This list identifies wastes from common manufacturing and industrial processes, such as solvents that have been used in cleaning or degreasing operations. Because the processes producing these wastes can occur in different sectors of industry, the F-listed wastes are known as wastes from non-specific sources.

• The K-list (source-specific wastes). This list includes certain wastes from specific industries, such as petroleum refining or pesticide manufacturing. Certain sludges and wastewaters from treatment and production processes in these industries are examples of source-specific wastes.

• The P-list and the U-list (discarded commercial chemical products). These lists include specific commercial chemical products in an unused form. Some pesticides and some pharmaceutical products become hazardous waste when discarded.

[edit] Characteristic Wastes

Waste that does not meet any of the listings explained above may still be considered a hazardous waste if exhibits one of the four characteristics defined in regulations — ignitability , corrosivity, reactivity, and toxicity:

• Ignitability – Ignitable wastes can create fires under certain conditions, are spontaneously combustible, or have a flash point less than 60 °C (140 °F). Examples include waste oils and used solvents. Test methods that may be used to determine ignitability include the Pensky-Martens Closed-Cup Method for Determining Ignitability, the Setaflash Closed-Cup Method for Determining Ignitability, and the Ignitability of Solids.

• Corrosivity – Corrosive wastes are acids or bases (pH less than or equal to 2, or greater than or equal to 12.5) that are capable of corroding metal containers, such as storage tanks, drums, and barrels. Battery acid is an example. The test method that may be used to determine corrosivity is the Corrosivity Towards Steel.

• Reactivity – Reactive wastes are unstable under "normal" conditions. They can cause explosions, toxic fumes, gases, or vapors when heated, compressed, or mixed with water. Examples include lithium-sulfur batteries and explosives. There are currently no test methods available.

• Toxicity – Toxic wastes are harmful or fatal when ingested or absorbed (e.g., containing mercury, lead, etc.). When toxic wastes are land disposed, contaminated liquid may leach from the waste and pollute ground water. Toxicity is defined through a laboratory procedure called the Toxicity Characteristic Leaching Procedure (TCLP). The TCLP helps identify wastes likely to leach concentrations of contaminants that may be harmful to human health or the environment.

[edit] See also

• Radioactive waste
• Toxic waste
• Remediation

[edit] External links

• The Household Chemical Encyclopedia - Over 100 Potential Sources of Household Hazardous Wastes
• Agency for Toxic Substances and Disease Registry
• The EPA's hazardous waste page
• The U.S. EPA's Hazardous Waste Cleanup Information System
• What Did We Know About Hazardous Waste and When Did We Know It, a Feb. 2002 essay by William Sanjour