Fundamental in Face mask safety is controlling pressure drops during respiration, thus avoiding airflow stress along seams and skin seals. Pugmercs utilizes a filter compliant with the guidelines laid down in International Journal of Occupational Medicine 2015 vol 25 pg 71-80 with an airflow rate of surgical masks of 85 l/min of constant. Pugmercs' Face mask has greater airflow than the study's Filtering facepiece respirators (FFR including surgical masks). The study's efforts indicated that greater airflow than 85 1/min do not decrease efficiency, thus our masks do not create a greater pressure drop than N95 Surgical masks.
Full study available here

On April 4, 2020 the CDC Covid page updated their guide for how to wear face masks to prevent pressure drops and secure a maximum fit factor. These guidelines for all cloth face coverings include the range your mask should be pulled down for maximum range of motion while using your personal protective equipment.

Face mask position
Face mask nose position

Research done by Cambridge University in 2013 related to influenza virus capture at .02 Micron (1/5 of covid-19 size) show 89% effectiveness with N95 surgical masks, which led us to use filter materials utilized in their studies with over 85% efficiency rate, within a 5% range of N95 Surgcial masks, the best available noncommercially.

The EPA's 2013 guide for Fit testing for full mask respirators can be generally used for appraising facemasks. The EPA uses a Fit Factor rating depending on the difference in pressure inside and outside of a facemask. Fit Factor equals (Cout/Cin). Our masks are designed for miminum pressure loss between the filter to achieve the best Fit Factor while maintaining a compliant filter.