(I also made a face mask with materials I found at home)
400 grams alginate, 500 grams plaster of Paris, 1325 grams water, 4 small wood screws, 2 elastic bands
Rapidly mix 400 grams alginate with 1200 grams water. Put your hand inside the mixture, cupping it like the shape of a mask for 8 minutes. Pull your hand out carefully. Then mix the 500 grams plaster of Paris with 125 grams water and pour it inside the bowl with the alginate. After 8 hours break the alginate apart in order to take out the plaster hand. Make 4 holes on the 4 edges of the hand. Tie the elastic bands to the opposite two edges.
Wear the hand mask and try to breathe.