Document daO5q6ndbMYVw3njrpk32vmye

MICHIGAN DIVISION March 16,1993 Th Dow Chemical Company Wlidlana. Michigan 48667 Douglas J. Kalinowski, C.I.H. Acting Division Chief Division of Occupational Health Michigan Department of Public Health 3500 N. Logan Street P.O. Box 30035 Lansing, Ml 48909 Mr. Kalinowski: This letter is a status update regarding the presence of vinyl chloride in the 591 building of the Midland location of The Dow Chemical Company. Results from a recent personal air monitoring survey conducted during filter change operations indicated that employee exposure potentials for vinyl chloride were above the 5 part per million ceiling guideline established in the MIOSHA vinyl chloride standard, rule 2260. The employees performing the filter changes followed existing written procedures which require the use of chemical protective clothing and full-face supplied air respiratory protection. Under normal operating conditions, two (2) operating personnel are present in the effected area of the building. The effected area is an enclosed room with ventilation through floor grating and the room is accessed through a doorway. Air monitoring data outside the affected area indicated levels of potential exposure below the action level. The following steps will be taken to evaluate and attempt to remediate the levels of vinyl chloride that are present during filter changes: - The room that contains the filters will be posted with signs and treated as a "temporary regulated area" during filter changes. Red flashing building lights will be activated to clear the building of nonessential personnel during filter changes. - Personal air monitoring during filter changes will be conducted when fitter changes occur (current frequency is every four to six weeks) until corrective actions are taken. - The filter designs and operating procedures will be re-evaluated in an attempt to reduce the levels of vinyl chloride present during filter changes. - A review of the medical surveillance program for all employees in 591 building will be completed. - The written operating procedures will be updated to reflect changes as a result of the action steps listed above. R&S148297 Mr. Kalinowski March 16,1993 Page 2 If you should have any questions please call. Regards, Industrial Hygiene Manager 258 Building Industrial Hygiene (517) 636-0609 Superintendent 564 Building SaranTM Polymer Plant (517) 636-3604 REDACTED R &si 48298 '"'Trademark of The Dow Chemical Company