1) Asphyxiation protection 2) Biohazard face wear 3) Breath protector 4) Chemical warfare protection 5) Gas helmet 6) Gulf War issue 7) Hazmat gear 8) Hazmat team item 9) Invention of world war i 10) It clears the air 11) It could be a lifesaver 12) Mask 13) Military defense gear 14) Military defense mechanism 
[n] - a mask with a filter protects the face and lungs against poisonous gases
respirator 1 gas helmet noun a protective mask with a filter; protects the face and lungs against poisonous gases