The WHO advises people to wear three-layer masks when they can't physically distance

Inner layer

Non-woven cotton forms final absorbent layer next to the face

Outer layer

Water-resistant synthetic material such as polypropylene limits droplets reaching nose and mouth

Middle layer

Material like polypropylene, which scores highly for filtration and reathability

The WHO advises people to wear three-layer masks when they can't physically distance

Outer layer

Synthetic water-resistant material such as polypropylene limits droplets reaching nose and mouth

Middle layer

Material like polypropylene, which scores highly for filtration and breathability

Inner layer

Non-woven cotton forms final absorbent layer next to the face