Document Jr8mX6xrzEmQOqpqb8gJymMGZ

FILE NAME: General Refractories Company (GRC) DATE: 1935 Sept DOC#: GRC019 DOCUMENT DESCRIPTION: Trade Publication Reference Documenting Knowledge that Visible Dust is a Serious Hazard Knowledge that Visible Dusts is a Serious Hazard Date: September 1935 Source: National Safety News: "No HalfWay Measures in Dust Control" by Arthur S. Johnson, 32(3): 17-18, 48-51 Exhibit No.: TLV 17 "I think we need to digress for a moment to visualize what I meant by 5 million particles of dust of such tiny size. We know it is invisible to the naked eye because it takes 15 to 20 times that much to produce a haze and even that isn't visible as particles of materials." p. 18