OSHA does not believe that a specific requirement mandating use of HEPA filters for air purifying respirators used for protection from Cr(VI) is justified, and has not included such a requirement in the final rule. For air-purifying respirators, in addition to the option of providing a respirator equipped with a filter certified by NIOSH under 30 CFR Part 11 as a HEPA filter, the Respiratory Protection standard allows employers several alternatives. Under 1910.134 the employer may also provide either (1) An air-purifying respirator equipped with a filter certified for particulates by NIOSH under 42 CFR Part 84; or (2) an air-purifying respirator equipped with any filter certified for particulates by NIOSH where dealing with contaminants consisting primarily of particles with mass median aerodynamic diameters (MMAD) of at least 2 micrometers. OSHA believes these requirements are appropriate for protection from exposures to Cr(VI).<\/p><\/blockquote>\n
That’s well and good but the standard respirator rating systems don’t talk about 2 micrometer particles. An N95 mask filters 95% of 0.3 micron particles. First, is 95% enough? Second, how good is it at 0.2 micron particles? 94% or 20%???<\/p>\n
That document mentions things like “The final rule establishes an 8-hour time-weighted average (TWA) exposure limit of 5 micrograms of Cr(VI) per cubic meter of air (5 [mu]g\/m\\3\\)”. That’s fine but I have NO idea what kind of exposure rate I might get with welding stainless steel. Maybe a gentle breeze will completely protect me, or maybe it’ll kill every living thing in in a 2 mile radius.<\/p>\n
I’ll continue my research but I’m bothered that my research is going so slowly. Where can I get answers?<\/p>\n","protected":false},"excerpt":{"rendered":"
I’m going to be doing a bit of stainless steel welding shortly. I know that the fumes can be dangerous, mostly because of hexavalent chromium, but I’m having a hard time getting the following question answered: Exactly what do I need to do to keep myself safe while welding stainless steel? Update 4-12-09: Here is […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-990","post","type-post","status-publish","format-standard","hentry","category-general"],"_links":{"self":[{"href":"https:\/\/www.lee.org\/blog\/wp-json\/wp\/v2\/posts\/990","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lee.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lee.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lee.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lee.org\/blog\/wp-json\/wp\/v2\/comments?post=990"}],"version-history":[{"count":0,"href":"https:\/\/www.lee.org\/blog\/wp-json\/wp\/v2\/posts\/990\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.lee.org\/blog\/wp-json\/wp\/v2\/media?parent=990"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lee.org\/blog\/wp-json\/wp\/v2\/categories?post=990"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lee.org\/blog\/wp-json\/wp\/v2\/tags?post=990"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}