Abstract: FDA’s Research on Face-coverings and Additively Manufactured Face Masks in Response to COVID-19.
CDC and WHO recommend the use of masks to reduce the spread of Severe Acute Respiratory Syndrome (SARS) CoV-2 that causes COVID-19. In this talk, FDA’s multipronged research on performance of face coverings and additively manufactured face masks will be discussed.
We will start by discussing a new and comprehensive characterization strategy we have developed to determine the performance of household materials against the primary modes of SARS-CoV-2 transmission: aerosols (typically < 1.0 µm), droplets (> 0.5 µm) generated during coughing or sneezing, and through direct contact with infected individuals or with a surface having virus-laden substance on it. We will also share our experience in characterizing over 20 household materials with various compositions and textures (e.g. cotton, polyester, cellulose, various blends, and combinations of materials).
After choosing a fabric, masks can be made at least in two ways – at home using a variety of construction methods, or by using the fabric as a filter in an additively manufactured (AM) face mask. Both strategies have been used extensively to overcome shortages of personal protective equipment such as FDA regulated surgical masks or N95 respirators. In the second part of the talk, we will discuss technical aspects to consider when choosing AM face masks. We will also provide information on the inward aerosols leakages to expect. Using such AM face masks as examples, we will also share some of our efforts to establish standard and credible practices for computational models used for fit-testing of 3D-printed face masks.
In the last part of our talk, we will introduce a comprehensive risk-assessment tool that we have developed specifically for COVID-19 to predict the probability of infection with individuals wearing AM masks or household fabric-based face coverings. The model is informed by the penetration and leakage values of the masks, as well as the characteristics of the population and the pathogen.