S. J. Pearce and L. B. Berger, List of Respiratory Protective Devices Approved by the Bureau of Mines, Information Circular 7636 (1952)

The U.S. Bureau of Mines' list of respirators and other breathing devices approved as of June 1, 1952, by S. J. Pearce and L. B. Berger of its Health Branch in Pittsburgh. It lists the approved self-contained breathing apparatus, gas masks, supplied-air respirators and abrasive-blasting hoods, dust, fume and mist respirators (including those for "pneumoconiosis-producing and nuisance" dusts) and chemical-cartridge respirators, with photographs, an explanation of the approval labels, and the names and addresses of the makers.