This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.
When the U. S. Bureau of Mines was established in 1910 it was provided that among its duties were to be investigations "in relation to the safety of miners and the appliances best adapted to prevent accidents... and from time to time to make reports of investigations." The information circular is one of seven thousand, one hundred and thirty such reports. It first distinguishes and defines the various forms of atmospheric contamination occurring in mines, such as gases, toxic and inert (oxygen deficiency); dusts, fumes, mists formed by disintegration, and fogs formed by condensation. It then describes the various forms of protective devices, such as gas masks specially arranged against each atmospheric contaminant; self-contained oxygen breathing apparatus; hose masks, and helmets for protection against abrasives and blasting. The requirements established by the bureau for each type of equipment are described and the tests which each must meet before gaining the
Testing Respiratory Protective Equipment for Approval. JAMA. 1941;116(26):2892. doi:10.1001/jama.1941.02820260066035