Posted 3 years ago
This is a box of Respirator Filters made by the Mine Safety Appliances Company, Pittsburgh, PA for use in "Dustfoe" Respirators. - The first patent number noted on the box is for the respirator (1936) and the latter patent number is for the filters themselves (1946). -- Mine Safety Appliances Company, or MSA, is a maker of sophisticated safety products that help protect workers who may be exposed to a variety of hazardous conditions. The company was formed in 1914 with help from Thomas Edison to develop a battery-powered cap lamp for miners to help prevent methane-related explosions caused by open flame lamps. From the 1930's to the 1980's, MSA produced fire helmets. The first generation was known as Skullguard and was a hard plastic produced in the 1930's to the 1960's. The second generation was a lighter plastic fire helmet, and was called Topguard, and was introduced in the early 1960's. The company’s product line currently includes gas monitoring and detection instruments, filter-type respirators, gas masks, breathing apparatus used by firefighters, thermal imaging cameras, firefighter helmets, ballistic body armor, military communications systems, a broad range of industrial head and fall protection products, and safety products for Do-It-Yourself consumers.