Adaption

To guarantee safe implementation of the N95 respirator disinfection within the VHP room, several iterations of the process were performed to optimize and confirm quality and efficacy of the process. First, to ensure that N95 respirators were safe to return to the healthcare worker, different types of bags with N95 respirators and biologic indicators were evaluated. The Tyvek pouches were chosen over paper bags because the latter absorbed more H 2 0 2 and required a longer time for off-gassing. Next, the impact of pouch placement on disinfection effectiveness was evaluated by packing some pouches tightly against one another and others loosely. Biological indicators placed within these pouches demonstrated effective disinfection for either configuration. A small sample of N95 respirators that had undergone one or more VHP cycles were set aside for and succesfully passed quantitative fit testing (TSI Portacount Respirator Fit Tester 8048). Finally, the orientation of each pouch was assessed after the first large-volume cycle yielded a positive biological indicator related to positioning of the Tyvek pouches. The orientation of each Tyvek pouch was changed from tightly packed standing on the side to a flat position, with the largest area of the pouch facing upward. This allowed for maximum exposure of the Tyvek pouch to VHP. The change in orientation of the Tyvek pouch decreased the number of N95 respirators that could be decontaminated during each cycle, but this change led to higher quality disinfection, as evidenced by consistently negative biological indicators. Initially, each disinfection cycle was capable of processing approximately 4,500 Tyvek pouches, with one N95 respirator in each pouch. In transitioning the position to flat, each disinfection cycle was reduced to approximately 750 Tyvek pouches. By incorporating additional shelves to each wire rack, each disinfection cycle is now capable of processing 1,500 Tyvek pouches.

Once the N95 respirator disinfection program was implemented on a larger scale throughout the hospital, it was noted that off-gassing times could be long and variable, ranging from 4 to 6 hours. To reduce the time needed for off-gassing, an additional fan was placed in the aeration room, decreasing this time to 3.5 to 4.5 hours. To further lower off-gassing time in the aeration room, a charcoal filter was added to facilitate rapid absorption of the VHP. This further decreased the off-gassing time to approximately 2 to 2.5 hours.