Most of their clothing is made from synthetic fabrics (from crude oil).
Their mandatory face masks are rarely natural cotton fabric.
Most masks are made from crude oil (petroleum) raw stock.
Materials for the BYD brand -- a typical single use, general purpose, 3-layer flat face mask:
— three breathable layers:
polypropylene non-woven fabric
— elastic ear loops:
polyester / nylon polyurethane blend
— nose clip:
galvanized iron wire covered by polypropylene wrapping
— with the added note that this product has no components made from natural rubber latex.