Modifying CDC Manikin Fit Evaluation Method to Match Fit Testing with Human Subjects

ALI HASANI, Joseph Dawson, Magdalene Fogarasi, Kirstie Snodderly, Dana Rottach, Daniel Porter, Suvajyoti Guha, Center for Devices and Radiological Health, US FDA

     Abstract Number: 408
     Working Group: Aerosol Science of Infectious Diseases: Lessons and Open Questions on Models, Transmission and Mitigation

Abstract
During COVID-19 pandemic N95 respirators offered a first line of defense for the healthcare workers against SARS-CoV-2. Although most typical N95 respirators are indicated for one-time use, significant shortage of these respirators led the healthcare workers to either use the respirators repeatedly or decontaminate and reuse them, resulting in many donnings. The three most important metrics for a respirator to offer protection to the wearer is its fit, filtration efficiency and breathability. While filtration efficiency and breathability can be measured using in vitro test methods, fit requires testing on human subjects. During COVID-19 pandemic, because of logistical challenges, a manikin fit test method from CDC’s NIOSH was proposed as an alternative to fit testing with human subjects and was often used. A manikin fit test method poses an advantage over actual fit testing as its not as resource intensive and does not pose a logistical challenge to implement. However, subsequently, it was determined that the manikin fit testing method is not as sensitive in predicting fit failure rates as tests performed on human subjects. In this presentation the authors will revisit the CDC’s manikin fit evaluation method, make simple changes to it and demonstrate how the changes made can result in the manikin method to show excellent agreement with the real world fit-testing results obtained with human subjects. Different examples will be provided with repeated donning and doffings, and decontamination methods (e.g. autoclaving and moist microwave generated heat).