They tested the masks using various materials including coal gas, chlorine gas, phosgene and various filters which included charcoal and even tobacco and were credited with creating the first Russian gas mask.
They tested the masks. They was using various materials including coal gas. They was using various materials including chlorine gas. They was using various materials including phosgene. They was using various materials including various filters. These various filters included charcoal. These various filters included even tobacco. These various filters were credited with creating the first Russian gas mask.