Document LnN66d8GvMmE8LMzraEXemEg

FILE NAME: Asbestos Cement Pipe and Sheet (ACPS) DATE: 1979 Apr4 DOC#: ACPS032 DOCUMENT DESCRIPTION: Unpublished Report by BC for EPA Barry I. Castleman ENVIRONMENTAL CONSULTANT / Box 230A Valley Road, Knoxville, Maryland 21758 /301-834-7787 FABRICATION OF ASBESTOS CEMENT PRODUCTS OCCUPATIONAL EXPOSURE TO ASBESTOS Report prepared for the U.S, Environmental Protection Agency Office of Toxic Substances A pril 4, i<?7? Fabrication of Asbestos-Cement Product* -- Exposure 1. A. Cross, Asbsstosis Research Council, XLO/1972 Saving and drilling -- in an enclosure 31-59 f/cc without dust extraction "incombustible boards" (hand sawing) 1-3.4 f/cc with extraction more than 200 f/ec w/o extraction more than 100 f/ec (power satiinfe) 1 .4-4.5 f/cc f/cc with extraction "other rept*d counts" 13-45 f/cc hand sawing w/o 63-186 f/cc power sawing w/o drilling -- 0.7-0.9 f/cc w/extraotion 1.0 - 5.4 f/cc w/o extraction 2. H. Forster (Germany), Ibid, pp 49-52 presents formula for limiting total dust (ag/cra) based on asbestos content says that 8 of 700 "asbestos joiners'* ..."with a maximum of 10 years exposure" have been transferred out of dusty work on medical orders. If. Troeper 3. AIA conference proceedings/1976 (7--#4) Discusses orogaessiva reductions of exposure with modifications of high velocity,low-volume exhaust ventilation. Worst case figures not given in text) and Trosper could not find them once when 1 called for the photos oat tbdhc he presented. Cutting Corspan tubular panel, the first-cut control fiber count was 33 f/ec. they got it down to 19 f/cc with better enclosure and higher vacuum, then, applying vacuum to openings in the panel as well as to the saw blade, they got down to 0.7 f/cc. Cutting "Flexboard" (the stuff used in ill-fated S Utah construction) with haphatard use of dust collector, they measured operator exposure at 8.7-10 f/cc, With plywood deflector sheet under the A-C panels, stiffened to prevent bowing, they got 2.8 f/ce. Trosper felt that they could do even better, but the only other counts for this continuous operation were 2.6 and 3*3 f/ce with best efforts at control applied. At end, he gives these figures for cutting flat sheet A-Ci "about 250 f/cc* before, down to 0.8 f/cc with the dust control device* This report points up the different sawing of A-C products of different and here the need is greatest as it products would present much greater situation. degrees of control available with machine shapes. Flat sheet seems easiest to control, is usually done indoors. Corrugated A-C difficulties in a real-life construction Hotel Hie controlled situations are most important as a matter of prevention, since they are reasonably reproducible. Uncontrolled sawing of any asbestos product is as much a danger as the enclosure permits, irrespective of the rate of dust generation. k, A/C Pip* Producer* Assn. spoasored reports 1977 Operator exposures were measured during fabrication operations using a variety of cutting tool*. fiber counts over periods usually lees than 15 B&nntes were up to 0.5 f/cc for sever pipe, 0 .3 - 2.0 f/cc for pressure pipe (which also takes longer to cut through). Somewhat lover values were obtained for the operator's helper's exposures. The remote controlled Wheeler pipe utter yielded the lowest values. Ihe exception to the above range of readings was the exposure measured during use of the abrasive diso saw, which was only used vet. The investigaters believed thaVl&cTactual contact surface during cutting was not being vetted, and that use of mist-wetting would yield improvement. However, as a practical matter, these values have to be regarded as minimal for use of the abrasive disc saw In cutting A-C pipe* mean values of separate trials, range in parentheses Quarts exposures were generally low, certainly far less alarming than the asbestos exposures. Though plastic bags and rigid shrouds were used to limit operator exposures during v9 of some tools, none of the devices used collected Uni any of the dust created by machining this pipe. Seme of the photographs show the work area blanketed with heavy patches of dust from the A-C pipes. This is anlte worrisome in light of the fact that 15-20# of the asbestos used in the USA (190,000+ tons/year) Is used in this product. Use of the abrasive disc was acknowledged to cause peak exposures and pos sibly time-averaged exposures in violation of the existing 0SHA standard* Though the industry presumably would discourage such practices, there is an urgent need to know the extent of abrasive disc cutting of A-C pipe that Is actually going on In the country. Squally worrisome Is the acknowledged need for"rigorous housekeeping" in controlling hasarda from dust and scrap cuttings. The state-of-the-art In dust control 1 totally unsatisfactory to all who regard asbestos to pose carcinogenic risks at levels below those permitted In the workplace. Cutting tools should be equipped with dust-capture devisee1 the solution her is $iot just having construction laborers sweep the dust up with brooms at the end of each day, I have heard that the A-C pipe industry acknowledges these things* 1. A-C pipe should not be used with water supplies of aggressiveness index less than 10. 2. Abrasive disc saw cutting of A-C pipe Is discouraged. What is the industry actually doing to assure that these fine suggestions are put into practice in the United States? 5. Barless at al. Snv. Res. l6il60 (197) Acute effects noted in workmen after a 5"*ooth construction job using lots of J-M (A-C) Flexboard. Samples taken after the damage was donei sweeping and moving scaffoldingi 3*^-6.2 f/cc drilling holes in boaki -- 0,57 f/cc Obviously* these samples were taken too late to have any value in do3 aresponse terms. Sweeping of a usual asbestos job gives values orders of magnitude higher (see this review* other parts of Cross* paper* and Mt. Sinai report on speckling compounds in Science, 1975) leading me to conclude that the sampling period was not the "first time those floors were cleaned after the job. Br correspondence with one of the authors of this report is useful in ap preciating the extent of asbestos exposure that still goes on in the 0.8. in fabrication of A-C sheet. The workers who did the construction, and who have developed measureahle pulmonary . airflow obstruc tion, were unaware that sawing up the panels indoors was dangerous. They had no recollection of seeing warning labeling on the Flexboards* and a later inspection showed that though a warning was on the boards, it was usually illegible. Workers said it was sometimes so dusty that it was difficult to sc across the building, during the job. Since s., 31 , of the asbestos used in the USA goes into A-C sheet products, and these products are commonly cut, indoors, without worker protection or dust capture, this represents a very serious public health con cern. As with A-C pipe, it would be worthwhile to survey manufacturers to see What they are doing to limit both the health teazcrd and liability associated with the use of their products. J&fscttSBion i There Is substantial public health hasard associated with fabrication of A-C pipe and A-C sheet products. While there exist moans to stjbs.tanti.ally reduce these hazards to workers fabricating: these products, those measure arc not standard practice and ay in fact be rarely practiced. The use of cutting tool equipped with dust a c l i e n t ! on d e v i c e s , for field fabrication, of A-c products, is most likely quite r a r e , 'i t e r afore, sites w here A-C product fabrication i s done continue to b& a source of public exposure to asbestos air pollution and water run-off* Much more information is needed from the field, and from the manufac turers responsible for the present regrettable state of affairs. USE OF THESE PRODUCTS SHOULD BE DRASTICALLY CURTAILED