Using respiratory protection is more than just providing a mask! In the United States, employers must ensure their proper functioning and have a regular maintenance and cleaning schedule. In general, respirators should be inspected for basic function prior to each use and cleaned as often as necessary to prevent the occurrence of unsanitary conditions.
This is clipped from the 1940s film "The Air We Breathe", a promotional documentary from the Mine Safety Appliances Company (MSA) on the importance of the air respirator to industrial health and safety. At the end, the film explains that industry and government cooperation has removed the "menace in the air" and urges workers in various industries to use the respirator.
Access this 1-minute, 42-second video by clicking on the link below.