Face Off: 3D-Printed Masks As a Cost-Effective and Reusable Alternative to N95 Respirators: A Feasibility Study

Background: One of the best methods for protection against respiratory diseases is the use of an N95 mask. Supply shortages have demonstrated a significant need for effective alternatives to N95 masks. Benefits of 3D-printed respirators over N95s include reduced cost and ease of production, widespread availability, reusability/sterilizability, and customizability. 3D-printed mask designs have been downloaded thousands of times; however, there is little to no data on the efficacy of these potential alternatives.

Methods: Three of the most popular 3D-printed respirator designs were modified to allow for the Occupational Safety and Health Administration (OSHA) quantitative fit testing that disperses saline into the ambient air and determines concentrations within the mask during multiple trials. Five volunteers conducted standardized fit tests of these masks, as well as an N95 and a KN95, and the results were compared.

Results: One of the 3D-printed respirators, low poly COVID-19 face mask respirator (mask 2), achieved a fit factor greater than 100 in every trial, representing sufficient fit according to OSHA protocols. The N95 mask achieved a sufficient fit in 60% of the trials, and none of the remaining masks provided a suitable fit factor reliably according to the OSHA fit test. Further trials showed no change in fit factor when different 3D-printable plastics are used or when a widely available high efficiency particulate air (HEPA) filter was used.

Conclusion: 3D-printed respirators provide a possible alternative to N95 masks to protect against respiratory pathogens such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Fit testing results demonstrate that certain 3D-printed mask designs may exceed the fit of N95 masks.