Document mx0ONVdGJVQ4rRxjwD5YQMZJ

CRI NUMBER if! & D REPORT L. r* V # I DOW CHEMICAL U.S.A. -f- ' llTaotW NBH2.12-28-1(2-5) RESTRICTED*, for us within Th* Dew Chemical Company only. jcc r Mg*. - DIG Chemical Biology Research t t e "" ~~ "" "" " SeDtember 24, 1973 pccows: *.<_ if *:>* lew r.ywaen 1 377 1 9080003 ASBESTOS EXPOSURES DURING MAINTENANCE, DEMOLITION AND TRANSITS FABRI 1 CATION, 500, 580, X199, 349, X376, 150 and 596 BUILDINGS IL'HOl- i r'JKi S ' M. F, Stevenson JUt WL\*i*VEc 5 S<CNA H. R. Hovle U- r~3Sc7?G< H. Flores f~U?S-73 DESCRIPTIVE SUMMARY WITH CONCLUSIONS-. (Include in this saace references o data books, reports, patents end publications./ to narlier rclotg-J Air samples to determine asbestos exposures were taken during various construction and demolition operations. The outdoor demolition work and indoor pipe stripping work at X199, X376 and 349 Building showed the lowest asbestos counts of the three areas sampled. The mainten ance work at 500 and 580 Buildings approached the maximum allowable concentration- Transite fabrication at 596 and 150 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. ST0OG-O982 DISTRIEUTION: R. P.. Langner, Industrial Hygiene Services, 607 Building E. B. Holder, M.D., Medical Department, 6C7 Building M. Xelyraan, Safety Department, 400 Building 5 . E. Harmon, Safety Department, 572 Building A. Hoyle, industrial Hygiene Section, 1701 Building L. Hagen, Power Maintenance, 500 Building v . Gunther, Power Maintenance, 500 Building M. J. BurreLl, 572 Building R. B. Willz.air.son, 572 Building R. P. Brentin, Foam Products Research, 657 Building M. G- Bussey, Foam Products Research, 657 Building Central Report Index (5), 566 Building -/Q&rzzJr s. , ' ? t'/ \ / -/O ~ 7.3 v ~ . j ,,-i* *f \ ST0000983 PROBLEM The Industrial Hygiene Section of DIG Chemical Biology Research was asked to evaluate asbestos exposures during maintenance, demolition and transite fabrication at various buildings in the Midland Division. CONCLUSIONS 1. Exposure to asbestos fibers was greatest during transite fabrication. Levels recorded at 596 and 150 Buildings approached and exceeded the maximum allowable concentration of 10 fibers/ml. 2. Exposure to asbestos fibers approached the maximum allow able concentration at 500 and 530 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. 4. Wetting dov/n and careful handling while removing asbestos insulation reduces airborne asbestos fiber concentrations (See Table 1 and 2}. -2- ST000.098U RECOMMENDATIONS 1. The use of procedures & equipment required by Occupational Safety and Health Act and Environmental Protection Agency re gulations such as signs, roped off areas, dust tight bags and approved respirators should be continued. 2. No friable asbestos debris should be dropped or thrown to the ground or to any floor below for any building or structure 50 feet or greater in height. This debris should be trans ported to the ground via dust tight chutes or containers. (See Federal Register, Volume 38, Number 65, 61.22 - EPA Emraision Standards). 3. When removing asbestos in an outdoor environment the section to be removed should be kept wet until final dis posal has been accomplished. 4. Workers working down wind from an asbestos stripping operation should be advised to wear respiratory protection until air samples are taken to prove otherwise. 5. Sawing equipment used ir. fabricating transite should be equipped with dust control devices. A wet cutting blade, local exhaust for the cutting area or a combination of the -3- 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 transits fabrications. i. Demolition. Operations - Asbestos was used extensively in cld buildings as an insulating material for tanks and pipes. Asbestos is a fibrous material and tends tc become airborne when buildings are demolished. Therefore, monitoring for asbestos at X199 and X376 Euildings was done in May of 1973, by the Industrial Hygiene Section of DIG Chemical Biology ST 00009 8 6 -5- Research. Breathing zone samples and area samples were obtained. These readings ranged from 0.11 to 0.48 fibers/ nl. (See Table 3} The ground was damp and equipment ranging from small bulldozers to large cranes was being used. Small pieces of flaky asbestos particles were seen on the ground and entangled in parts of the steel structures, A transite sample was obtained for analysis to determine the percent asbestos and related elements (See Table 4). None 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 2one 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 that a workers exposure can be controlled. The majority of respirators worn were net Dow or U. S. Bureau of Mines approve 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 ST0000987 strong wind coming from the east entrance ana 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 "3M 2304" with R57 cartridge; 3m Brand., No. 371C 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 scrimping operation was going on. A strong wind was blowing northwester! toward other maintenance workers not envoived in asbestos ' removal. Precautionary measures taken included all but the wetting down process. Samples were taker, 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. ST0000988 3. Transite Fabrication - Transite is a heat resistant substance used at Dow for reacccr enclosures, etc. This fabricating substance is known to contain about 30 to 40% chrysotile, one of six different types of asbestos (See Table 4 and AL#060798). Prior to the installation of transite the material must be cut to proper size. Sawing transite creates a very dusty situation not only for those doing the cutting but for others working in the immediate area. ' Samples were obtained at 595 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. Tne samples taker, here were primarily outdoors and brisk"winds tended to disperse rt.e dust. (Tables 5 and 7} SAMPLING AND ANALYSIS Breaching zone and general area air samples were coliecred by two different methods: 1. For breathing zona samples personnel sampling pumps with millipore filter cassettes (0.S micron pore size) were used at sample rates of about 2 liters per minute. ST 0000989 -8- 2. General area air samples were obtained by using personnel pumps and gast pumps. Filters used with the gast pumps were 47 ran in diameter and 0.8 micron pore si2e. Sampling rate of about 23 liters per minute was obtained bv use of a No. 5 limited orifice. Fibers on the filters were counted by standard phase contrast microscopy technique at 450 magnification by the Midland Division Microscopy Laboratory (ALrr64-788, 65-073., 059824, 059837 and AA#73-271). Bulk samples were obtained of asbestos and transite to determine content by percent composition (AL#060798, AL060786). These results were obtained by x-ray diffraction analysis. ST0000990 TABLE L Stripping Asbestos From "L" Cracker. 530 Building Sample Number _________________Operation 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 Asbestos Concentration (fibers/ml) 1.8 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- ST000099I TABLE 2 Removing Asbestos From Pipes, 349 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 6 General area Asbestos Concentration (fibers/ml) 0.7 2.3 0.2 L.5 0.5 0.3 NOTE: E:reathing zone samoles exceuc where indicated. -10- STOQ 0095)2 ?AELE 3 Demolition of Old Buildings with Asbestos Insulation on Pipes, Reactors and Transits Wails: X199 & 376 Buildings Sample Number ODeration X3 76 Building 7 Area sample 8 Outside cabe of crane Asbestos Concentration (fibers/ml) 0.43 0.29 XI99 Buildinc 9 Man 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 budding - down wind 0.18 0.12 0.11 0.13 -11- ST0000993 TAELS 4 Transits Sample Frc-ra X375 Building - Sent to X-rayDiffraction to Determine Asbestos Concent and Other Crystalline Materials Substance Found Chrysotite Calcite (CaCO^) Vaterite (CaCO^) Quartz Noncrystalline Percent 30-40 10-20 15-25 15 5-15 Range of percent was confirmed by removing soluable car bonates (caicite & vaterite) and rerunning insolu3ble residues. A loose dust sample was collected at 580 Building from crane microscopic examination indicated that the dust is probably anositc, one of the six different types of asbestos present. -12- STOCK) 09 94 TABLE 5 Stripping Asbestos From #14 Eoiler, 500 Building Sample Number _________________Operation___________________ Asbestos Concentration (fibars/ml) o 0 0 OV 1 2 3 4 5 3 / 8" G 10 Pulling asbestos block insulation from boiler Pulling asbestos block insulation from boiler Area sample, approximately 6 feet from work area Pulling asbestos from boiler Picking up loose asbestos Picking up & emptying into demoscers Area sample, approximately 2C feet from, work area but down wind from crafu Area sample approximately 8 feet lateral from work area Pulling asbestos from bciler Area sample apprcxirately ~ feat from, work area 6.0 ' 0.2 1.3 0.7 4.5 1.0 .9 0.1 -13- $1*0000995 TABLE: 6 Fabrication of Transite, 596 Building Sample Number 1 2 3 4 5 Operation Cutting transite with rotary saw Asbestos Concentration (Fibers/ml) 9.7 Man installing transite on platform 1.6 Background, around doorway 0.1 Measuring transite board and cutting with, rotary saw 11.1 Kan 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 ST 0000996 TABLE 7 Transite Fabrication, 150 Building Sample Number 1 2 3 Coeration Cutting transite with rotary saw Man standing to immediate right of operating saw Man standing to left of saw holding board down Asbestos Concentration (Fibers/ml) 40.7 32.0 42.5 NOTE: All samples were taken in the breathing zone