Document 5LgBDyJQxYd0kMBzdDJRJY25R

Everything for Mine and industrial Sajety CABLE AD DRESS "M IN SA F" P IT T SB U R G H BRAD D OCK .T H O M A S AN D M EA D E S T R E E T S July 23, 1946. M.S.A. Research Lab. 327 Craft Avenue Pittsburgh (13), Pa. Dr. Robert A* Kehoe Kettering Laboratory of Applied Physiology College of Medicine - Eden Avenue University of Cincinnati Cincinnati (19), Ohio Dear Dr. Kehoe: Replying to your l e tte r of July 2, 1946 in which you inquire regard ing suitable resp irato ry protection from lead fume. The GMA-1 type of can ister th a t you mention in your le tte r w ill not be satisfacto ry for lead fume* This is a can ister f ille d with activated charcoal and contains only a cotton f ilte r , the efficiency of which is too low fo r lead fume. For fume of the m etallic type, such as lead , we recommend the M.S.A. MComfort Metal Fume Respirator (B. M. Approval No. 2139)* This is approved by the Bureau of Mines fo r lead fume and a l l other fumes th a t are no more toxic than lead. You understand, of course, th a t th is i s merely a mechanical f i l t e r device and w ill give no protection from toxic or discomforting gases around smelters, such as sulfur dioxide from roasting sulfide ores or HCN i f a cyanide process i s used. The M.S.A. Air Line Respirator (B. M. Approval No. 1909) may also be used fo r m etallic fumes i f the hose lin e is not an encumbrance You did not indicate d ire c tly what type of a smelter you are dealing with; also, whether i t is the primary metal recovery process or the secondary in which scrap would be used. However, I am assuming that since th is i s an in te re s t of the Ethyl Gasoline Corporation, you might be dealing with a primary lead smelter. In the past we have had a v ariety o f lead fume problems. One of these was the exposure th a t attended the making of leaded s te e l. One of the procedures was to throw lead shot into the ingot mold immediately a fte r the mold had been f ille d with molten s te e l. There were also some fluxes and other chemicals used in th is process with the re s u lt th a t they needed both fume and gas protection. This was not realized by the industry u n til they had put the process into large scale operation with the re su lt th a t we had a rath er hurried c a ll for some sort of emergency protection. In response we quickly made a small can ister th at com bined fume and gas protection and have supplied these in lim ited q u an titie s. We have not tooled up to make them in large quantities owing to the fact th a t a t the time the need occurred, the Bureau of Mines did not have a schedule fo r such N 7997 CO. Dr* R* A. Kehoe .2 July 23, 1946. a combination re sp ira to r and, of course, re did not know what we would have to meet* Such a schedule now e x ists and I may t e l l you confidentially th at we are conducting some development work but i t may not be coupleted for six months. This same type of can ister has been procured by the s te e l construction and demolition industry where i t becomes necessary to burn out riv e ts or cut with gas flames stru c tu ra l members th a t have been heavily coated with lead p ain t. I t happens th at in addition to the lead smoke there are gases and vapors of an odorous nature th a t nauseate workmen* I was pleased to hear from you and to have the opportunity o f giving you th is information* I f there is anything additional th a t I can a s s is t with, I w ill be pleased to give any help th a t I can* YJPYiDER Director of Research and development