a radioactive waste. Chemical constituents can be separated from mixed waste by using supercritical fluid extraction (e.g., carbon dioxide), which is now available commercially.
• Surface contamination from radioactively contaminated lead can be removed by dipping the contaminated lead into a solution of 1 M hydrochloric acid. After rinsing the lead with water, it usually can be documented as nonradioactive. The acidic wash and rinse solutions contain radio-nuclides and lead and must be handled as mixed waste. However, decontaminating the lead results in a smaller mass of mixed waste and allows the decontaminated lead to be reused or recycled. Commercial rinse products are also available for this purpose.
• Incineration is advantageous as a treatment for many types of chemical–radioactive waste, especially those that contain toxic or flammable organic chemicals. Incineration can destroy oxidizable organic chemicals in the waste. To comply with radionuclide release limits, USNRC licensees need to control emissions and may need to restrict the incinerator’s waste feed. Radioactive ash is typically managed as a radioactive waste. It is important to keep toxic metals (e.g., lead, mercury) out of the incinerable waste so that the ash is not chemically hazardous according to the TCLP test. On-site incineration minimizes handling and transportation risks; however, incineration of chemical waste is regulated by EPA and requires a permit, which is beyond the resources of most laboratory waste generators.
8.C.1.4 Commercial Disposal Services for Mixed Waste
Because of the great variety of laboratory mixed waste, it is often difficult to find a facility that can manage both the radioactive and the chemical hazards of the waste. In general, existing commercial disposal facilities are in business to manage mixed waste from the nuclear power industry, not waste from laboratories. Several commercial disposal facilities that accept mixed waste from off-site generators do exist in the United States. These sites have the capacity to manage LSF, halogenated organics, and other organic waste. Treatment capacity exists for stabilization, neutralization, decontamination/macroencapsulation of lead, and reduction of chromium waste.
In spite of this capacity, many types of laboratory mixed waste have no commercial repository. No commercial mixed-waste disposal facilities exist for waste contaminated with most toxic metals (such as mercury) or for lead-contaminated oils. Commercial disposal capacity likewise does not exist for high concentrations of halogen-containing organics and other TCLP waste, such as waste that contains chloroform.
8.C.2 Chemical–Biological Waste
Medical, clinical, and biomedical research laboratories generate waste that contains potentially infectious materials and viable agents that are capable of causing human disease. Biohazardous wastes can include tissues and carcasses of experimental animals involved in infectious disease studies; cell cultures of infectious agents; contaminated sharps, gloves, gowns, glassware, and instruments; and blood and other clinical specimens. Biohazardous waste presents a hazard to persons who handle the waste within the generating facility. Waste decontamination is the treatment method to control or eliminate the exposure hazard prior to waste handling and disposal. The OSHA Occupational Exposure to Bloodborne Pathogens rule (29 CFR § 1910.1030) established federal requirements for the collection and containment of certain laboratory wastes that contain human blood or body fluids for the purpose of preventing exposure of personnel to bloodborne pathogens. This rule promotes the use of standard microbiological practices including safe practices for handling biohazardous wastes. The rule also requires the treatment of all contaminated waste from research laboratories handling human immuno-deficiency virus (HIV) and hepatitis B virus (HBV) and other bloodborne pathogens by incineration or decontamination by a method known to destroy the pathogens within the waste materials. Federal regulations regarding transport and incineration may apply to the off-site management of nonlaboratory biohazardous waste, such as waste generated in medical or health care settings. Several states and local jurisdictions regulate the treatment and disposal of biohazardous wastes.
The Centers for Disease Control and Prevention (CDC) of the U.S. Department of Health and Human Services and the Animal and Plant Health Inspection Service of the U.S. Department of Agriculture promulgated rules under the Public Health Security and Bioterrorism Preparedness and Response Act of 2002 for the possession, use, and transfer of select agents and toxins. The rules require the destruction of select agents that are contaminants in any waste by validated laboratory decontamination methods, such as chemical decontamination or autoclave sterilization, before disposal.
Special procedures are required in disposing of multihazardous waste that includes both hazardous chemicals and materials contaminated with microor-