Document MoK20JYB2LdXarEvGdeY7D5j

I 50683 DOW CHEMICAL U.S.A. TEXAS DIVII FREEPOST. TEXAS 77S41 ENVIRONMENTAL HEALTH REPORT ASBESTOS INTRUSION INTO A-1800 BLOCK FROM SANDBLAST WORK IN THE PIPEWAY file no- A7-1288 nATF November 21. 1977 author R. E. Bosche1 'ttkLj CHECKED DATE /<?77 Summary Monitoring was done of the dust being generated by the painter/blaster crews working overhead in the pipeway adjacent to the A-1800 production plant. No significant asbestos content was found in this dust. Levels were .001 to .01 fibers per milliliter. ST00I5637 hhs Distribution P. C. Gay B-101 B. G. Parrack A-510 W. L. Watts A-711 Mike Trevino B-108 ^ile AN OPERATING UNIT OF THE DOW CHEMICAL COMPANY File A7-1288 2- - November 21, 1977 INTRODUCTION At the request of Maintenance Department supervision, this survey was done September 12, 1977. METHODOLOGY By placing Bendix (Environmental Services, Baltimore, Md.) personnel sampling pumps at specifically chosen spots in the plant, downwind of the blasting work, it was possible to draw a set rate of air through openfaced Millipore cassette filters (Millipore Corp., Bedford, Mass.)catalog number MAWG 037AO. These were then delivered to Central Laboratory Department where they were cleared and fibers * 5 micrometers were counted by phase contrast microscopy. The air flow calibration was check before and after the sample period and if different, was averaged and this was then considered constant over the sample period. The reported value from Central Laboratory is fibers per square of the grid on the filter disc. This value is multiplied by 90 (the number of available squares on a disc) and related mathematically with the total air sample volume. RESULTS Table 1 is a listing of the locations monitored in this survey and the quantities found at each of the locations. The concentrations of asbestos fibers ranged from 0.001 to 0.01 fibers per milliliter. ST00I5638 I EHS EEB/bbs 11-21-77 r File A7-1288 TABLE I NUMBER 1. 2. 3. 4. 5. LOCATION FIBERS On column 20* NW of PT-22C Tank(duplicate) 0.01 South side of A-1800 inside of covered bridge. 0.003 On column 20' NW of PT-22C tank (duplicate) 0.004 On handrail of foot bridge crossing J*0.003 over ditch & pipeway, south side of(duplicates) A-1800 by A-1859 building 0.001 ST00I5639 f