Antibacterial ZH Therapeutics Mask

The U.S. CDC (Centers for Disease Control and Prevention), WHO (World Health Organization), and public health officials recommend wearing face masks to control the spread of the novel coronavirus, which causes COVID-19. People are now wearing many different types of face coverings, including bandanas, hand-sewn masks, and disposable medical masks. In many cases, mask choice is dependent on availability; people use what they have. But how effective are each of these face coverings?
Respiratory masks (RM) are protective devices covering a part of the face. They are designed to protect both the person who wears them and the immediate environment from breathable pollutants (respiratory poisons or bacterial/viral pathogenic organisms). Different masks can be classified as I) full masks (normed following EN 136) and II) half and quarter masks (EN 140) (Figs. 1, 2, 3 and 4). While a full mask covers the whole face, a half-mask fits from under the chin to above the nose, a quarter mask fits from the top of the nose to the top of he chin. The breathing resistance varies proportionally to the density of the mask material.