Document 5bMjVYj0g0G3DxnR1YE16rpV8

1*0 50983 PLAINTIFF'S EXHIBIT DOW-2931 DOW CHEMICAL U.S.A. TEXAS DIVISION FREEPORT. TEXAS 77541 ENVIRONMENTAL HEALTH REPORT EVALUATION OF ASBESTOS EXPOSURE TO INSULATORS AT GLYCOL "A" file no, A18-237 niTF November 21. 1973 author ..JL.L-. , Si.lverthorne CHECKED DATE. S//Z//7S~ Summary Contractor Insulator exposure to asbestos fibers were evaluated during the removal of insulation on two columns at Glycol "A". The timeweighted average (the average exposure of asbestos fibers to employees during an eight hour work day) and peak exposures to asbestos fibers are within acceptable levels, although the peak exposures could approach maximum allowable concentrations due to the variability in the asbestos handling procedures. The employees should continue to wear respiratory protection during the handling of asbestos, and every effort should be made to wet down the asbestos insulation before and during removal. CD CD cn CD Distribution F. A. Newman A-510 /File AN OPERATING UNIT OF THE DOW CHEMICAL COMPANY File No. A18-237 2- - INTRODUCTION Environmental Health Services was asked to evaluate the exposure of Insulators to asbestos fibers during the removal of asbestos insulation from two reaction towers at Glycol "A". METHODOLOGY Breathing zone and general area air samples were collected on 47 mm-diameter(,8 micron pore size) membrane filters at a sample rate of about 2.0 LPM. The air pumps used were M.S.A. permissible portable personnel pumps. The fibers on the filters were counted by the standard phase-contrast microscopy technique at 450 magnifi cation by the Texas Division Microscopy Laboratory. DISCUSSION Table A shows the insulator exposures to asbestos fibers based on an eight hour work day when insulation is being removed from reaction towers. His time weighted average and peak exposure are within acceptable levels based on the present OSHA standard. Table B shows the results of the sample analyses for the various Insulator operations. The highest asbestos fiber concentration, up to 1.29 fibers/ml, were found during the actual removal of insulation by the employee. Because of the variability In the asbestos handling procedures the employee peak exposures could exceed the allowable ceiling concentration.' CONCLUSION 1. The employees time weighted average and peak exposures to asbestos fibers are within acceptable levels. STOO 1:5110 RECOMMENDATION 1. Ashestos insulation should be stored in plastic bags, tagged and sealed for disposal. 2. Employees who work regularly with asbestos should have clean work clothes daily. (Work clothes should not be taken home for laundering). File No. A18-237 -3- RECOMMENDATIONS (continued) 3. Continue the work practice of wearing respiratory protection whenever asbestos is handled. 4. Employees with significant exposure should shower at the end of the work day. 5. Water should be used to wet down the insulation before and during the dismantling operation. This will reduce the possibility of asbestos fibers becoming air borne. 6. Environmental measurements should be made annually to determine the adequacy of precautions taken. 7. 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