Document 3QdNL5ZZzzgzx97MwJp6GQXQJ

MR. T. B. BONNEY, PITTSBURGH 24 ( . ii H. H. -REDDER MECHANICAL ENGINEERING DIV PITTSBURGH OFFICE MR. C. F. AMES MASSENA WORKS July 30, 1965 RE; AUTHORIZATION M-40793 - DOST COLLECTION SYSTEMS Thank you for your letter dated July 23 with copies of the Department of Labor' s Notice of Plan Approval for your two systems covered by the above Authorization with the condition that "discharge to the outdoors Is required". Although the amount of discharge piping Is relatively small, we are still of the opinion that to be consistent with the purpose for installing new systems for providing maximum safety, that exhaust stacks should be eliminated. The efficiency of the Type N Rotoelone will hold dust concentrations well below the threshold limits which would create an environmental problem, and the elimination of any duct work in this type of equipment further reduces the hazzards Inherent with handling aluminum dusts. We cannot help but feel that the Department of Labor has overlooked these facts. We have attached some written comments made by Mr. R. W. Andrews, Jr. and a copy of Mr. T. B. Bonney#s letter dated July 28, both relating to your specific problem. Each contains considerable Information In support of the reasons for operating without discharge ducts.. Using that portion of the information provided herein, that you feel to be of value, we suggest that you submit written request to the New York State Department of Labor requesting that stipulations requiring discharge ducts be deleted from their approvals. It seems fitting that these negotiations be continued from your office; however, we will be happy to furnish further support should It be required. Your request might point out that a precedent has Jjeen established relative to this type of installation based on the same considerations governing our concern in this Instance. Also, that Alcoa's Industrial Hygiene Division has approved this installation using Mr. Bonney'8 supporting reasons. Finally, pointing out the hazzard of a duct on the discharge of a collector as a potential source of fire or explosion due to accumulation of dust over extended periods of operation or from hydrogen gas generated from the wetted fines. We are quite confident that a carefully prepared explanation of these facts will satisfy the authorities. Kindly let us know if we can further assist you in any way. H. H. REDDER HHR:cf Ends. cc - Mr. T. B. Bonney - Pittsburgh 24 Route File: Mr. R. W. Andrews, Jr., H. W. Cooley EXHIBIT AL-1583 ARCH 18603