Labelling Suggestions for Manufacturers of Reusable Masks
People making masks for sale should specify the materials (fabric category, composition, weave, weight, thread count) for each layer and the number of layers (e.g., outer layers quilters’ cotton 100%, plain weave, 150 gsm, 150 TPI; middle layer spunbond polypropylene 70 gsm). Useful information for mask manufacturers can be found here.
Information on industry-grade spunbond non-woven polypropylene is available here, and where to purchase it is here.
The international standard for reusable masks is ASTM 3502.