Management of mixed wastes from biomedical research

Mixed radioactive and chemical wastes generated by biomedical research were characterized, and various treatment methods for reducing their volume were evaluated. These wastes consist primarily of organic solvents used in the extraction and purification of radiolabeled biomolecules that are contaminated with low levels of the long-lived radionuclides, 3H and 14C. The Rockefeller University's mixed wastes fall into three broad chemical categories: phenol/chloroform, acetonitrile/water, and mixtures of miscellaneous solvents such as carbon tetrachloride, benzene, and other hazardous chemicals. Currently, with the exception of liquid scintillation cocktails (deregulated in 1981), there are no commercial disposal outlets for mixed wastes nor may they be stored legally for more than 90-180 d. Most of these mixed wastes can be effectively rendered into nonradioactive chemical and aqueous radioactive waste, both of which can be disposed of in accordance with existing regulations. However, to do so requires a Resource Conservation and Recovery Act (RCRA) Part B permit for licensure as a treatment, storage, and disposal facility. For many university research facilities, this may require financial and personnel resources disproportionate to the small amounts of waste produced. Also, such treatment, if not done properly, presents potential occupational hazards from the direct handling of waste materials. Deregulation of certain mixed wastes would be the safest, most cost-effective, and practical method for dealing with many mixed wastes of biomedical origin. In any event, a national regulatory solution must be found.