... seal which is suitable for different face.2.MF18type gas mask Specifications: Service life, min Penetration Leakage ... arsine, phosgene, chloropicrin, bromomethane, lewisite gas, mustard gas, sarin, vx gas, toxic smoke, and fume, benzene, hydrogen phosphide, chlorine, acetone, alcohols, anilines ... 4.Usage maintenance and maintain4.1.The selection of gas mask 4.1.1. checking the position between ...