Reuse of disposable personal protective equipment is traditionally discouraged, yet in times of heightened medical applications such as the SARS CoV-2 pandemic, it can be difficult to obtain. In this article we examine the reuse of disposable gowns with respect to still providing personnel protection. XR7, a fluorescent powder, was used to track contamination of gowns after manipulation of rodent cages. Mouse cages were treated with XR7 prior to manipulations. Disposable gowns were labeled for single person use and hung in common procedure spaces within the vivarium between usages. A simulated rack change of 140 cages was completed using XR7-treated cages. One individual changed all cages with a break occurring after the first 70 cages, requiring the gown to be removed and reused once. To simulate research activities, 5 individuals accessed 3 XR7-treated cages daily for 5 d. Each mouse in the XR7-treated cages was manipulated at least once before returning cages to the housing room. Disposable gowns were reused 5 times per individual. Gowns, gloves, clothing, bare arms, and hands were scanned for fluorescence before and after removing PPE. Fluorescence was localized to gloves and gown sleeves in closest contact with animals and caging. No fluorescence was detected on underlying clothing, or bare arms and hands after removing PPE. Fluorescence was not detected in procedure spaces where gowns were hung. The lack of fluorescence on personnel or surfaces indicate that gowns can be reused 1 time for routine husbandry tasks and up to 5 times for research personnel. A method for decontamination of used gowns using Vaporized Hydrogen Peroxide (VHP) was also validated for use in areas where animals are considered high risk such as quarantine, or for fragile immunocompromised rodent colonies.

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Studies published in 1994 and 2000 established a temperature range of 143–180 °F for effective cage sanitization in animalfacilities. These 2 studies were, respectively, theoretical and based on experiments using hot water to sanitize bacteria-coated test tubes. However, such experimental methods may not capture the practical advantages of modern washing technology or account for the routine use of detergent in cage wash. Moreover, these methods may not translate to the challenges of removing adhered debris and animal waste from the surfaces being sanitized. A sample of highly soiled cage bottoms, half of which were autoclaved with bedding to create challenging cleaning conditions, were processed at 6 combinations of wash and rinse cycles with 125 °F, 140 °F, and 180 °F water with detergent. All cycles were equipped with a data logging device to independently verify temperatures. After washing, cages underwent visual inspection and microbial sampling consisting of organic material detection using ATP detection and Replicate Organism Detection and Counting (RODAC) plates. Cages with any amount of visible debris failed inspection, as did cages that exceeded institutional sanitization thresholds. Results indicate that wash and rinse temperatures of 140 °F for a programmed wash duration of 450 s and rinse of 50 s effectively clean and disinfect both highly soiled and autoclaved cages. Accounting for both steam and electrical energy, these parameters result in an annual savings of $21,867.08 per washer on an equivalent run basis using the current institutional standard of 180 °F.

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