Background: Personal protective equipment (PPE) is a critical need during the COVID-19 pandemic. Alternative sources of surgical masks, including 3D-printed approaches that may be reused, are urgently needed to prevent PPE shortages. Few data exist identifying decontamination strategies to inactivate viral pathogens and retain 3D-printing material integrity. Objective of Study: Test viral disinfection methods on 3D-printing materials. Methods: The virucidal activity of common disinfectants (10% bleach, quaternary ammonium sanitizer, 3% hydrogen peroxide, or 70% isopropanol and exposure to heat (50oC, and 70oC) were tested on four 3D-printed materials used in the healthcare setting, including one used in a surgical mask design developed by the Veterans Health Administration. Inactivation was assessed for several clinically relevant RNA and DNA pathogenic viruses including SARS-CoV-2 and HIV-1. Results: SARS-CoV-2 and all viruses tested were completely inactivated by a single application of bleach, ammonium quaternary compounds, or hydrogen peroxide. Similarly, exposure to dry heat (70oC) for 30 minutes completely inactivated all viruses tested. In contrast, 70% isopropanol reduced viral titers significantly less well following a single application. Inactivation did not interfere with material integrity of the 3D-printed materials. Conclusions: Several standard decontamination approaches effectively disinfected 3D-printed materials. These approaches were effective in the inactivation SARS-CoV-2, its surrogates and other clinically relevant viral pathogens. The decontamination of 3D printed surgical mask materials may be useful during crisis situations where surgical mask supplies are limited.

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Additional testing was performed to characterize the filter media properties: thickness, solidity, and effective diameter. An inverted microscope or digital caliper (if >2 mm thick) was used to measure filter thickness. When using the microscope, a sample was supported on its edge between two glass microscope slides and photographed. This was true of single-layer and multi-layer filter media. A Samsung Galaxy S7 (S/N RF8H82NM9KT) was held on the microscope eyepiece using a CNC Supply Microscope Adapter. A 10X ocular and 10X objective were used on the microscope. ImageJ (National Institutes of Health, Bethseda MD) was then used to determine the length of the filter thickness after scaling with a photo of a 1-mm stage micrometer with 100 divisions. Solidity, or "packing density," was determined by cutting 1.3-cm circles from the media with a punch and weighing them on a 6-place