When the COVID-19 pandemic hit, personal protective equipment (PPE), especially facemasks and respirators, were in short supply due to unforeseen, increased demand and shortages in raw materials and finished products. As can be imagined, the month of March 2020 brought a tremendous quantity of inquiries flowing into laboratories worldwide regarding validation of new masks and validation of processing masks for reuse (re-processing). Prior to the COVID-19 pandemic there was no standard, established process for validation of mask reuse. Particularly, the biggest concerns tended to be with the masks that were originally sold as N95 respirators, but which were being reprocessed in some form to allow for reuse of this rapidly diminishing commodity.
