Document a24zjvaoQLQ102Q8j3VawRpb

| .jR & 0 REPORT v fa/dfo : r" DOW CHEMICAL U.S.A. f- iiSTRlCTES: miliiii Th Qw Ch.mtcal (nr ly* r?;i 'l>t ! DIG Chemical Biology Research oN*UBHi'H2"A.1'a2---^28-1f2-S*---- September 24, 1973 lACSdyNT ho. NuMiJX 377 9080003 ASBESTOS EXPOSURES DURING MAINTENANCE, DEMOLITION AND TRANSITS FABRI CATION, 500, 580, X199, 349, X376, 150 and S96 BUILDINGS CR| NUMBER .V0* * njRi M. F. Stevenson 1 H6,HATUt H. R. Hoyle DESCRIPTIVE SUMMARY WITH CONCLUSIONS) 1?M. . (Includa in .. ^ thi* ipaca -------------------v s. h. Flores 't^X/T * r*f*rtnc* data book*, and ~/a to acHiar raiatad rapartt, poranrs and publication*.) Air samples to determine asbestos exposures were taken during various construction and demolition operations. The outdoor demolition work and indoor pipe stripping work at XI99, X376 and 349 Building showed the lowest asbestos counts of the three areas sampled. The mainten ance work at 500 and 530 Buildings approached the maximum allowable concentration. Transite fabrication at 596 and ISO Buildings , approached and exceeded the maximum allowable concentration of 10 fibers per milliter (fibers/ml). Anyone working in the immediate vicinity of such jobs should use approved respiratory protection. DISTRIBUTION) R. R. Langner, Industrial Hygiene Services, 607 Building B. B. Holder, M.D., Medical Department, 607 Building M. Kelyman, Safety Department, 400 Building 3. E. Harmon, Safety Department, 572 Building H. R. Hoyle, Industrial Hygiene Section, 1701 Building L. L. Hagen, Power Maintenance, 500 Building V. Gunther, Power Maintenance, 500 Building M. J. Burrell, 572 Building R. B. Williamson, 572 Building R. P. Brentin, Foam Products Research, 657 Building M. G. Bussey, Foam Products Research, 657 Building Central Report Index (5), 566 Building V 4 p| ' jr T"*" s. &. '-dLr co 0) /2-/Q-7 T0000982 DOLI 07721 ST0000983 i. PROBLEM The industrial Hygiene Section of DIG Chemical Biology Research was asked to evaluate asbestos exposures during maintenance, demolition and transits fabrication at various buildings in the Midland Division. CONCLUSIONS 1. Exposure to asbestos fibers was greatest during transite fabrication. Levels recorded at 596 and ISO Buildings approached and exceeded the maximum allowable concentration of 10 fibers/ml. '- r 2. Exposure to asbestos fibers approached the maximum allow able concentration at S00 and S80 Buildings during the removal of insulation from boilers and crackers. 3. Asbestos exposures were minimal while removing covering from pipes at X199, X376 and 349 Buildings. r r 4. Wetting down and careful handling while removing asbestos insulation reduces airborne asbestos fiber concentrations (See Table 1 and 2). 2- - DOU) 07722 ST0000985 -4- above two methods should be considered as possible engineering control methods. Air sampling will be required to assure satisfactory control of asbestos fibers. 6. A possible reduction in the speed of the cutting blades when fabricating transite should also be considered as a viable method in the reduction of airborne dust. . DISCUSSION ' As per Federal Register, volume 37, Number 202, paragraph 1910.93a, every employer shall monitor the air breathed by workmen who might be exposed to asbestos to assure that the concentration of asbestos fibers is within accepted limits. The areas monitored thus far include demolition of buildings, removal of asbestos insulation from pipes, boilers and crack ers (maintenance purposes) and transite fabrications. 1. Demolition Operations - Asbestos was used extensively in old buildings as an insulating material for tanks and pipes. Asbestos is a fibrous material and tends to become airborne when buildings are demolished. Therefore, monitoring for asbestos at X199 and X376 Buildings was done in May of 1973, by the Industrial Hygiene Section of DIG Chemical Biology DOU 07724 ST00-00986 -5- Research. Breathing rone samples and area samples were obtained. These readings ranged from 0.11 to 0,48 fibers/ ml. (See Table 3) The ground was damp and equipment ranging from small bulldozers to large cranes was being used. Snail pieces of flaky asbestos particles were seen on the ground and entangled in parts of the steel structures. A transits sample was obtained for analysis to determine the percent asbestos and related elements (See Table 4). Sone of the precuationary measures required by regulation was in evidence at the time of sampling. Removing asbestos insulation from pipes can present high exposure possibilities. At 349 Building, breathing zone samples were taken while removing insulation, the results ranged from 0.3 to 2.3 fibers/ml. The men at this operation were handling the asbestos carefully. They were using dust tight bags to contain the insulation as it was removed. Pipes had been wet down earlier that morning.. The results indicate .i chan a workers exposure can be controlled. The majority of respirators worn were not Dow or U. S. Bureau of Mines approved and further education of the contractors is needed. 2. Maintenance Operations - Here, as above, removing asbestos insulation was the primary concern. At 500 Building asbestos was being removed from a boiler. It was an indoor job with a dou 0772& ST0000987 -3- strcnc wind coming from the east entrance and blowing northerly. No signs or ropes were in evidence. Disposable respirators were worn but were not the type recommended. Recommended types of respirators and filters to be used while working with asbestos are* Mine Safety Appliance Ultra Filter respirator with Cartridge "H"> Amiercan Optical with respirator "BM 2304" with R57 cartridge: 3M Brand, No. 8710 respirator, disposable. Disposal of asbestos was improper no dust tight bags were used at all. Asbestos removal was done in two different ways. First, the asbestos was shoveled into a wheel barrow and emptied into an open dumpster. Second, the asbestos was shoveled into the running water used to carry fly ash, etc., into holding areas. See Table 5 for results of 500 Building sampling. At 580 Building, '*L" cracker, an outdoor asbestos stripping operation was going on. A strong wind was blowing northwesterly toward other maintenance workers not envolved in asbestos removal. Precautionary measures 'taken included all but the wetting down process. Samples were taken prior to and after the work area was wet down (See Table 1) . The operator was told that he should wear his respirator whenever working in this area and that samples would be taken. The results ranged from 1.5 to 9.1 fibers/ml. DOW 07726  ST000Q988 3, Transit Fabrication - Transit is a heat resistant substance used at Dow for reactor enclosures, etc. This fabricating substance is known to contain about 3 0 to 40% chrysotile, one of six different types of asbestos (See Table 4 and AL#060798). Prior to the installation of transits the material must be cut to proper sire. Sawing transits creates a very dusty situation not only for those doing the cutting but for others working in the immediate area. ' Samples were obtained at 596 and 150 Buildings. At 150 Building results ranged from 32 to 42 fibers/ml. The work done here was in a partially enclosed area. At 596 Building sample results ranged from 0.1 to 11.1 fibers/ml of air sampled. The samples taken here were primarily outdoors and brisk winds tended to disperse the dust. (Tables 6 and 7) SAMPLING AND ANALYSIS Breaching zone and general area air samples were collecced by two different methods: . 1. For breathing zone samples personnel sampling pumps with millipore' filter cassettes (0.8 micron pore size) were used at sample rates of about 2 liters per minute. . DOUJ 07727 : STOQO099O TABLE 1 Stripping Asbestos From "L" Cracker, 530 Building Sample Humber .___________ Operation . _______ g Asbestos Concentration (fibers/ml) 1 Picking up loose asbestos (wet) 2 Picking up loose asbestos (wet) 3 Stripping asbestos from Cracker (not wet) 4 Stripping asbestos from Cracker (not wet) 5 Stripping asbestos from Cracker (wet) 6 Crane Area - down wind 1.3 1.5 8.9 9.1 6.2 4.8 NOTE: Sample 6 was a general area sample and sample 3 was loose dust picked up off the crane. All others are breathing zone samples. ' 9- " DOW 07729 ST0QQ099I / TABLE 2 Removing Asbestos From Pipes, 249 Building Sample Number - Operation 1 Removing insulation & bagging asbestos 2 Removing pipe covering 3 General area 4 Removing insulation & bagging 5 Removing insulation from pipes General area Asbestos Concentration (fibers/ml) 0.7 2.3 0.2 1.5 0.S 0.3 NOTE: Breathing zone samples except where indicated. oow 07730 -10- ST00Q0332 TABLE 3 Demolition of old Buildings with, Asbestos Insulation on Pises, Reactors and Transits Walls: X199 & 376 Buildings Sample Number _________ Operation X376 Building 7 Area sample 8 Outside cabe of crane Asbestos Concentration (fiber s/ml) 0.48 0.29 XI99 Building 9 Han operating catipillae (loading , truck with debris) 10 Man operating small utility bull dozer* - pushing debris into stacks 11 Man operating crane 12 Area sample, approximately 100 feet north of building - down wind 0.18 0.12 0.11 0.13 -11- 00* 07731 {'4 w 0000995 TABLE 6 Fabrication of Transit, 596 Building Sample Number i 2 3 4 5 6 Ooeration Cutting transits with rotary saw Asbestos Concentration {Fibers/ml) 9.7 Man installing transits on platform 1.6 - Background around doorway 0,1 Measuring transits board and cutting with rotary saw 11.1 Man installing panals, occasionally drilling screw holes 1.2 General area, breathing zone height, around doorway \ 1.3 NOTE* All samples are in the breathing zone DOW 0773* ST00OO996 TABLE 7 Transit Fabrication, 150 Building Sample Number 1 2 3 Operation Cutting transits with rotary saw Man standing to immediate right of operating saw Man standing to left of saw-- holding board down Asbestos Cone entx ation (Fibers/ml) 40.7 32.0 42.5 NOTE: All samples were taken in the breathing zone DOU 07735