Respiratory Effectiveness of Cloth Masks

The shortage of medical masks and respirators led to an explosion of cloth mask offerings. In the absence of any regulatory requirements, and appropriate guidance, the medical masks vary greatly in their performance and have become more of a fashion item. We review the filtration mechanisms and test methods and show data on common offerings. Almost exclusively, the data suggest that cloth masks do not offer much of a protection, and many are poorly designed with only the pressure drop and fogging in mind; these compromise the performance of the entire mask. While cloth masks do not offer significant respiratory protection, it is still critical that masks are worn during pandemics regardless in that they do reduce the number of aerosols expelled by the wearer.