Development and Validation of Waste Decontamination Cycle in a Biosafety Level 3 Laboratory

Steam sterilization has been used for decades to effectively kill microbial contaminants in a variety of medical and commercial settings. One of the most critical aspects of safe operations in biosafety level 3 biocontainment laboratories (BSL-3) is the effective inactivation of biological select agents in the waste generated in these environments. The Instituto Nacional de Enfermedades Virales Humanas "Dr. Julio I. Maiztegui" (INEVH, Pergamino, Argentina) is an institute that offers epidemiological surveillance, production of biological reagents, and production of biologicals for human use and studies of reservoirs and vectors. Some of the activities need to be done in a BSL-3 that provides biocontainment, ensuring that the materials are decontaminated before they leave the facility. The objective of this study was to design and validate a decontamination procedure for biological waste from the BSL-3 facility that guarantees steam sterilization processes.

The amount and the distribution of biological waste into the autoclave and other physical parameters were defined and evaluated by calculating lethalities.

We evaluated autoclave basic factory programmed cycles, and it was concluded that the sterilization autoclave cycle was not efficient for decontamination of waste. A new simulated load distribution had to be defined.

The results demonstrated that autoclave factory default settings can be inadequate for sterilizing highly infectious waste, depending of types of waste, such as animal carcass and animal bed waste.

These results of the validation process can set the standard to the design of waste management protocols to ensure effective treatment of highly infectious biological waste.