Demonstration of a simple do-it-yourself test of mask barrier function using widely available commercial products.

By December 2020, SARS-CoV-2 caused the deaths of nearly 1.5 million people worldwide. A common strategy to mitigate spread of the virus is mask wearing. Considerable data demonstrate that masks can create an effective barrier to the respiratory droplets that can carry the virus. However, the effectiveness of consumer masks for this purpose varies, and there are currently no minimum standards that mask manufacturers must meet. Therefore, a need exists for an at-home test of mask barrier function. Here, we demonstrate a simple test to compare the function of selected masks using widely available materials and resources.