Autoclave inactivation of infectious radioactive laboratory waste contained within a charcoal filtration system

A model system was developed previously for disposal of solid laboratory waste that is both radioactive and heat sensitive, e.g., HIV. A double polypropylene bag with charcoal vent filter and absorbent was designed to meet requirements for both steam sterilization and disposal as solid radioactive waste. Earlier work demonstrated the effective containment of radioactive gases by the filter and inactivation of organisms as heat sensitive as HIV. We sought to broaden the application of this model to ensure inactivation of microorganisms that are more heat resistant than HIV. The efficacy of steam sterilization using water or solutions of iodophor, hypochlorite, or hydrogen peroxide was studied under constant temperature and time conditions. The systems were monitored with internal probes, physical, chemical, and biological indicators. Biological indicators documented inactivation when bags containing hydrogen peroxide (3%) were autoclaved for 60 min at 121 degrees C. Synergistic activity between hydrogen peroxide and autoclave conditions significantly reduced processing time.