Document 3J1bnNqx1nKZRoJz26ymXVVLx

DOW CHEMICAL U.S.A. LOUISIANA DIVISION PLAQUE MINE, LOUISIANA 70764 604 687-4321 INDUSTRIAL HYGIENE REPORT Conducted screening survey for mercury vapors in the Instrument Shops throughout the division and followed up with a second survey after improvements were made. The first survey indicated that twelve of seventeen shops were above OSHA regulations. The second survey was much improved and all shops now meet OSHA standards (0.05 milligrams per cubic meter). It is recommended that a vacuum cleaner be purchased by the Instrument Department and designated for mercury clean-up in the division Instrument Shops. Periodic mercury clean-up and annual surveys should be scheduled by the department. Contaminated containers- should be disposed of through the use of the landfill area. DISTRIBUTION LOUISIANA MIDLAND Bob Huet Bldg. 4103 Harold Hoyle Bldg. 1707 Oran Smith II 4103 R. Langner " 607 P. J. Blaylock Roy Walker II 4105 II 3301 Plant Superintendents TEXAS Medical Dept. Bldg. ?^03 R* Daniel Bldg, B~101 AN OPERATING UNIT 01s THE DOW CHEMICAL COMPANY ta $ Jti - 3 PfMB x ^OLE DO 011616 CONFIDFNTTAl 2- - INTRODUCTION Conducted a screening check for mercury vapors in the Instrument Shops throughout the division to determine approximate vapor levels. This screening survey was followed up by another survey employing Drager tubes (specific for mercury vapors). METHODOLOGY Mercury vapor levels were first monitored with the Mercury Sniffer, model MV2, manufactured by the Bacharach Instrument Company. The second series of data was collected with the model 31 Drager Multi Gas Detector Pump. RESULTS OF FIRST SURVEY The initial survey revealed that twelve of seventesi Instrument Shops were above the OSHA standard of 0.05 mg/m3. There were nine shops in which free mercury was found in small amounts due mostly to spills from Manometers which did not have proper check valves or mercury capacitor tanks (return wells) installed. It was also found that mercury vapors were being released when the Manometers were in operation and not equipped with proper protective devices such as activated carbon tubes on vent, or vented to the outside. COMMENTS During the time interval between the two surveys most Instrument Shop personnel made a good effort to clean up the free mercury that was found and Manometer safety equipment was installed and vented in eleven shops. Four of the remaining six shops (Caustic, Glycol II, Light Hydrocarbons II and Utilities) have the necessary safety equipment but haven't installed it yet. The Chlorinated Solvents plant has purchased an AMETEK Electropneumatic Calibrator which will eliminate the mercury Manometers in their shop. RESULTS OF SECOND SURVEY Results of the second survey are much improved and only one Instrument Shop (Poly B) failed to meet the OSHA standard of 0.05 mg/m3 and corrective action was taken there. The Poly B Shop Manometers, which are contained inside a panel and built into the wall, were dissambled and the area behind the panel was thoroughly checked and cleaned. The Manometer protective equipment was installed and vented outside the building. The shop was monitored again three days later which revealed less than 0.05 "mb/m3 mercury vapors. CONCLUSIONS Due to the difficulties encountered in cleaning up mercury spills it is recommended that a vacuum cleaner be purchased and designated for mercury clean up in all Instrument Shop areas. The Instrument Department should schedule periodic mercury clean up and annual surveys. The contaminated containers should be disposed of through the use of the landfill area. CDO0NFIOENTTAV MERCURY SURVEYS Location I April . 1975 II Mav. 19,75 1 (mg/ms) Manometer Free Hg (mg/m3) Manometer Hr Level Vented Found Hg Level Vented Comments Caustic .093 Cellulose .130 Chlor-Alkali II Chlorinated Methanes Chlorinated Polyethylene Chlorinated Solvents . .060 .070 , .150 .150 Chlorine Glycol I Glycol II Light Hydrocarbon I Light Hydrocarbon II I lyethylene "A" Polyethylene "B" Power R&D Utilities Vinyl ! .050 .140 .038 .060 .250 .030 .300 .043 .060 .700 No No No No No No No No No No No No No No No No No Yes Yes Yes No Yes Yes No Yes No Yes Yes No Yes Yes No No Yes < .050 < .050 < .025 < .050 < .050 < .050 No Yes Yes Yes Yes Yes < .025 < .025 < .025 < .050 < .050 < .050 < .050* < .050 < .050 < .050 < .050 Yes Yes No No ' No Yes Yes No Yes No Yes Manometer safety equipment purchased should be Installed soon Portable building used for Instrument Shop - difficult to keep uncluttered AMETEK electropneumatic Calibrator is to be installed - will eliminate mercury vapors Manometer safety equipment installation has begun Rechecked after clean up and safety equipment hookup (< 0.05) In process of moving to new quarters safety equipment will then be installed Instrument Shop to be enlarged soon will probably find some free mercury when tearing out old workbench and cabinets NOTE - All obvious mercury spills appear to have been cleaned up, however, it can be reasonably assumed that these are certain amounts of free mercury in out-of-the-way places that are difficult to detect.