Is there an adequate alternative to commercially manufactured face masks? A comparison of various materials and forms

Background: There is a worldwide shortage of medical-grade face masks. Donning masks can play an important role in curbing the spread of SARS-CoV-2. Aim: To conclude whether there is an effective mask for the population to wear in public that could easily be made during a medical face mask shortage using readily available materials. Methods: We determined the effectiveness of readily available materials and models for making a face mask. The outcomes were compared with N95/FFP2/KN95 masks that entered the Netherlands in April–May 2020. Masks were tested to determine whether they filtered a minimum of 35% of 0.3-μm particles, are hydrophobic, seal on the face, are breathable, and can be washed. Findings: Fourteen of the 25 (combinations of) materials filtered at least 35% of 0.3-μm particles. Four of the materials proved hydrophobic, all commercially manufactured filters. Two models sealed the face. Twenty-two of the 25 materials were breathable at <0.7 mbar. None of the hydrophobic materials stayed intact after washing. Conclusions: It would be possible to reduce the reproduction rate of SARS-CoV-2 from 2.4 to below one if 39% of the population would wear a mask made from ePM₁ 85% commercially manufactured filter fabric and in a duckbill form. This mask performs better than 80% of the imported N95/FFP2/KN95 masks and provides a better fit than a surgical mask. Two layers of quilt fabric with a household paper towel as filter is also a viable choice for protecting the user and the environment.