Document KvL3YOVZBadRBoBK06g1d68w

FILE NAME: Asbestos Cement Pipe and Sheet (ACPS) DATE: 0000 DOC#: ACPS100 DOCUMENT DESCRIPTION: J-M Unpublished Report - Review of "Chrysotile Asbestos Fibers in Drinking Water from Asbestos-Cement Pipe" --***** 4<tfal&li<t>famti*01 ,* , ,' ` \ ww rtrn ffir if im tirltMtviiinfiv ni' i i*>in i"rr~i^ i. im i n n f ii i f V i -- , ^r ** ^ ,- rin iiVa m. mi,Vt -f -- REVIEW OF "CHRYSOTILE ASBESTOS FIBERS IK DRINKING WATER FROM ASBESTOS-CEMENT PIPE* By T. A. Scripps*, J. P. Leineweber*, H. L. Olson3 and J. F. Welch* / 1 Statistician, Research Department, Manville Corporation, Denver, Colorado 3 Technical Director, Health, Safety and Environment Department, Manville Corporation, Denver, Colorado 3 Manager, Environmental and Engineering Development, Pipe Division, Johns-ManvlUe Corporation, Denver, Colorado 4 Vice President, A/C Pipe Producers Association, Arlington, Virginia TABLE OF CONTENTS I. Introduction , Assumptions About the Aggressiveness Index HI. Experimental Design and Data Collection IV. Statistical Analysis V. Confounding Factors VI. Agreement with Other Data VE. Conclusions - REFERENCES -v LETT OF TABLES Table I Table 2 Table 3 - Vtr` `p L Paired Before and After Results - Chrysotlle Fibers Per Liter from Cooper et aL System X - Comparison of Asbestos Levels in Water Before and After Conveyance Through A/C Pipe Comparison of Water Quality - System C and System X (Sample 1) fSE 1 2 5 10 11 14 15 17 8 14 IS 7543 V* . *#' IMTRODUCnOK The paper, "Chrysotile Asbestos Fibers in Drinking Water from Asbestos-Cement Pipe" by Knnarek et al *is a supplementary analysis of data taken from a larger two part study z *M>5i6 that examined the presence of asbestos fibers in drinking water and disease incidence in the San Francisco (California) Bay Area. In the paper, the authors question "the validity of aggressiveness indexes for prediction of fiber release from asbestos-cement pipes." Their arguments are based on a purported "demonstration of substantial increases in asbestos fiber counts in :.! * % nonaggressive drinking water" flowing through asbestos-cement (A/C) pipe within ! I selected distribution systems. *'J* ^1 This review will comment on the Aggressiveness Index (AI) as a measure of :4? asbestos release from asbestos-cement pipe, the assumptions and inferences made by the investigators, experimental design, sampling and data analysis techniques, and possible explanations for the study's observations. li5 7546 I II. ASSUMPTIONS ABOUT THE AGGRESSIVENESS INDEX The underiving assumption of the paper is, in the authors' words, " ... that there is a positive correlation between fiber release from the walls of A/C pipe and the 'aggressiveness' or corrosiveness of water." It is further assumed th a t this correlation is quantitative, consistent and predictive, These assumptions are incorrect. . Prior to development of the Aggressiveness Index (AI), manufacturers recommended that the use of A/C pipe in water with a Langller Index of -2.0 (AI=12.0) or less would be inconsistent with maintaining the 50-100 year design lifetime of water systems. In the early 1970's, engineering consultants requested that American Water Works Association (AWWA) and American Society for Testing and Materials (ASTM) specifications for A/C pipe further define conditions of product use in so-called aggressive and non-aggressive waters. It should be emphasized that the manufacturers' recommendations and AWWA/ASTV guidelines^ were developed solely for the purpose of ensuring long-term, structural integrity of A/C pressure pipe. The AI was not conceived to be a predictor of asbestos fiber release. As the U.S. Environmental Protection Agency (EPA) Drinking Water Research Division has stated on this matter The use of the Al as a predictor of the condition of the interior surface of the pipe in contact with the drinking water and its tendency to retain or release asbestos fibers has come about in spite of the fa ct that the original Intention of the Index was to outline water conditions that might cause structural failure of the pipe, The difference In application is very"significant. (emphasis in original) - 2- 7547 m sm m m m There is e substantial body of scientific evidence supporting the vJew that there is neither a quantifiable nor a predictive relationship between any corrosion index and levels of asbestos released from A/C pipe into drinking water. In 1980, an EPA researcher testified! Further work has shown that the aggressive index is not the perfect indicator of whether a water will corrode an asbestoscement pipe and release fibers. The calculation of the aggressiveness Index alone Is not always sufficient to predict actual behavior of A/C pipe.10 And in 1981, EPA again underlined the imprecision of the AI, almost flatly rejecting the Al-fiber release hypothesis Substantial field and pilot plant data, combined with comprehensive evaluation of many of the Important chemical complexation and precipitation reactions occurring in drinking w ater, give compelling evidence that the Al has immense shortcomings with regard to use as predictor of fiber release and interior surficial pipe condition that enjoin against its use under most circumstances,* The Agency's mast recent published work on the Aggressiveness Index states: There are several major avenues by which the AI is open to criticism as an indicator of corrosivity and fibef release, the manner in which has most frequently been used. 1 The EPA paper goes on to detail the deficiencies of the AI in reliably predicting fiber release, concluding: The Aggressiveness Index as traditionally conceived Is not theoretically sound from a chemical standpoint to predict fiber release and degradation of the Interior pipe surface In systems that are undersaturated with respect to calcite. Fortunately, it has generally proved to predict falsely pipe deterioration more often than to predict falsely pipe stability in field situations, * * * Observations of A/C pipe sections from many localities conclusively demonstrate that natural Inhibitory factors, such as those mentioned, are commonly the pipe protection mechanism, not calcite saturation, 2 The AI Is a technical guideline governing the selection of the proper type o f A/C pipe for waters of differing aggressiveness. It is based on empirical observations and physical testing of specimens from A/C pipe systems. Based on published analyses^, it can be concluded that the AI is comfortably conservative In assuring long-term structural integrity of the product. In summary then, the basic assumption of the Kanarek et al paper i.e. that there is a valid correlation between the AI and fiber release, simply Is incorrect. The AI was never meant to correlate with fiber release from A/C pipe and in fact, extensive studies by the U.S. Environmental Protection Agency demonstrate this rather conclusively. .......... K iTn?" " - J - . ,,. , ' *V ' ** V , f ,' ^ TV/> . ^ '**>*>,"* DI. EXPERIMENTAR DESIGN AND DATA COLLECTION i J 1 The original study design and. collection of data, which are the bases for this paDfer; gave little or no consideration to selecting a sample population i (representative distribution systems! in such a way that a valid generalization to a i larger population (all distribution systems In the San Francisco area, for example) i could be made. \ The data suggests no purposeful sampling technique to determine whether the A/O : distribution systems were contributing asbestos to water conveyed through them. The authors 'explain this awav by stating the collection of "before" and "after" A/C pipe samples " ... was only one of several factors Involved In this overall assessment of asbestos in drinking water supplies." The facts are that the study of fiber release from A/C pipe was a m atter of tertiary importance to the authors. By its own admission, the original study had limited relevance to A/C pipei 's Samples were taken before and after lengths of asbestos- cement pipe (See Table 18). Although, in some cases there were apparently substantial Increases as a result o f the' 'wafer passing through the pipe, the data appear Inconsistent, This 1 S u d F dfd not Include the amount o f asbestos-cement pipe in the various distribution systems as a variable in the analysis because of its questionable significance and the difficulty of determining its location, age, and dimensions. 4 (emphasis added). al An EPA funded report on the asbestos sampling plan for the San Francisco Bay area study states: 4 I The contribution (if any) of asbestos-cement pipe to the level 9 of asbestos found in drinking water has yet to be determined. The Cooper study was not specifically designed to measure the -5- 7550 might be attributed to the use of asbestos-cement ( The harshest criticism of the study's design and data collection/analysis comes from the Environmental Protection Agency, which funded the original project: The only suggestion of asbestos cement pipe being attacked by water with an aggressiveness index greater than 12 was in conjunction with an epidemiological study done in the Bay Area "i. of California. The data on the pipe were not gathered i specifically for th irp u r^ 'corrostoiTbut were pmled from the overall study* data'"set. Some information about the syHems'sucii.as previous tapping procedures and whether the Dipe had been deteriorated from some other cause were not available. None of the pipe had been dug up for inspection, unfortunately. 1 did not feel after reviewing the i 3 dhaaptpaenthinagt""I'IcnoJtuWldciceo''n' 'siydsetrmthsi.s a" c'o"mmpolreete cpoimctpulreeteofstwudhyat^iiss ' 3 necessary before 1 can conclude1'^"'eoyrcaion' occurs with' wateir'"oir an aggressiveness index of greater than...12,iq> lem pSteadded} With these facts in mind, any statistics generated from this sampling data base n and any conclusions drawn from those statistics, must be considered of dubious value, >/ \ ; ' * * A closer examination of the samples themselves reveals equally serious compromises in sound science, The authors purport to have thirty-nine pairs of "before" and "after" water samples corresponding to "before" and "after" flowing through A/C pipe. There are not thirty-nine paired samples. Firstly, consider a day on which a single "before" sample Is taken from a water treatm ent plant discharge and four "after" samples are taken from residential taps after flowing through varying lengths of A/C pipe. This sampling plan is not generating four independent "before/after" pairs. The four "before" samples are artificial -- they are not independent of each other, they are the same observation because only eoe l. 7551 I sample was actually taken. In the paper, nineteen of the thirty-nine pairs of samples were selected In this manner. Table 1 (page 8) lists the original data, Indicating which pairs are from Identical "before" samples. No attem pt is made by the authors to account for this dependence. This is particularly ironic In light of the authors' statement that various taps were sampled "to determine the Continuity of values throughout the distribution area." So, although the paper acknowledges the need for a supplementary analysis to account for this dependency. It was never undertaken. Second, consider a 'given section of A/O pipe sampled on different days. Each repeated sample contributes Information regarding the change in fiber counts within that section. Only to the extent that the given section of pipe is better characterized does each repeated sample contribute Information with respect to characterizing the distribution system as a whole. These repeated samples logically should not be allowed to have as much influence in an analysis of the total system as a pair of measurements on different sections of pipe within the system. In the paper, fifteen of the thirty-nine samples are from sections of pipe with repeated measures. Again, no attem pt was made by the authors to account for these two different sources of variation in fiber counts. It should be mentioned that these "within-section" repeated measurements are desirable. They supply information concerning the variability of fiber counts over time. This information can be used to establish limits on the uncertainty associated with the expected number of counts for a given sample. Unfortunately, as seen above, the authors do not use the data to this end. , , ?, J < , , sv ' ,, ^ >fc> V'*^'v * ,v ? TABLE 1 PAIRED BEFORE AND AFTER RESULTS CHRYSOTILE FIBERS PER LITER PROM COOPER ET AL2 Pair Number 1 2 3 4 5 6 7 8 , 0 10 11 System A A A A A A A A A A A Before A/C Pipe < 1.0 x 104 (A) 6.0 XID4 < 2.5 x 104 < 2.0 x 104 2.0 X 105 1.0 X 105 < 1.0 x 104 < 2.0 x 104 1.0 X105 < 2.0 x 104 4.0 x 10 After A/C Pipe < 2.0 x 104 R1 tC9 < 2.0 xlO 4 R1 <1.0 x 105 R1 < 2.0 x 104 R2 1.5 x tO5 R2 3.0 x 105 R2 < 2.0 x 104 R3 1.4 x 105 .R3 2.0 x 106 R3 < 2.0 x 104 1.0 x 105 12* 13* 14* IS* , M? 17 18* 19* 20* 21* 22 A A A B ' B B B B B B B 5.0 x 104 5.0 x 104 5.0 x 104 < 5.0 x 103 < 5.0xl03 1.6 x 105 < 2.5 x 104 < 2.5 x 104 2.5 xlO4 < 2.5 X ID4 1.8 x 105 5.0 XlO4 (B) 3.5 X 105 5.0 x 105 < 7.0 X 103 < 2.5 X 104 5.4 x 105 R4 1.5 x 105 R4 1.9 x 106 R5 5.4 X 104 < 2.5 x 104 3.8 X 104 R5 8 p* r~ f 1 U ** M '& .>Mi A-t m . i't ?-iwp M m Number 23* 24* 23 26 27* 28* 29* 30* 31 32 33* 34* 35* 36* 37 38 39 System Before A/C Pipe B 7.6 x 105 B 7.6 x 105 B 2.8 x 105 B 2.5 x 104 C 5.0 x 104 C 5.0 x ID4 C 5.0 x 104 C 5.0 x 104 * 2.5 x 104 - 2.5 x 104 C 2.0 x 10* c 2.0 X ID5 c . < 2.5 x 104 c < 2.5 X 104 c < 2.5 x 104 - 4.0 x 104 - < 2.5 x 104 After A/C Pipe 2.0 x 105 4.0 x 105 2.0 x 10s 2.0 X 105 6.2 x 106 3.4 x 107 2.5 x 108 < 1.0 x 10 2.0 x 105 3.0 x 10s 8.0 x 10 6.4 x 106 2.0 X 107 1.5 X 108 5.4 x 104 4.0 x lO 4 1.6 x 10s < The fiber count is below the lowest detectable limit listed. * One 'before' sample for multiple 'after' samples. RX Replication of same section of pipe. , 9- 7554 IV. STATISTICAL AHALYSB Although the shortcomings of experimental design and data collection are sufficient to Invalidate this research, there also exists erroneous data analysis. Assume for discussion purposes that there are Indeed thirty-nine pairs of "before/after" samples with the results as reported: nineteen increases, eleven ties, nine decreases. The authors claim a two-sided significance level of 0.039 from a sign test corrected for continuity. This is not obtained by the standard formula X2 = f / a - b / - l ) 2 (/24.5-14.5/-1)2 39 a 2.03 Where each tie is treated as one-half an increase and one-half a decrease. The l significance level of the above chi-square value is 0.150 -- not considered to be a significant result. So, not only does the study fail to employ sound scientific principles in data collection, it incorrectly calculated the significance associated with the most Important test statistic. -10- 7 i r- r- 0 JU ' - ...... ... te a . ta.fct. V. CONFOUNDING FACTORS The paper concludes that in comparison to the "before" water In one system (System O) " ... an Increase of U 5 times the number of fibers" was observed after passage through sections of A/C pipe. The authors go on to hypothesize a number of possible explanations for these apparent increases, including! - breakup of naturally-occurring fiber after flow through A/C pipe - size of pipe - water flow rate - alternate wetting and drying of (pipe) surfaces - quality of Joint materials used - corrosive cleaners In use to flush sections of pipe - tapping of pipe - the possibility that hydrants or "dead ends" could have acted as "reservoirs" for fibers, producing artificially elevated fiber counts. The paper then dismisses out of hand, without any supporting Justification or substantiating data, the possibility that any of the above factors accounted for the apparent asbestos releases In System C. There is no explanation as to whether these factors might explain smaller apparent increases in Systems A and B. Conspicuous by Its absence in the list of potentially confounding factors Is perhaps the most important -- variations in levels of naturally-occurring asbestos in the source waters. Many of the source waters in the study have fiber concentrations in excess of one million fibers per liter (mfl) and some over 20 mfL Other -11- 7556 investigators have pointed out the ubiquitous nature of asbestos in Bay Area drinking waters; t As can be seen from the charts (representative asbestos values in Bay Area water systems), none of the major water districts servicing the San Francisco Rav Area are free of asbestos fibers. Individual asbestos measurements range from ip!" fibers per liter to 1.8 x 10 fibers per liter of finished w a te r.8 To demonstrate the possibility (If not probability) of significant asbestos variations in source waters, consider the sources for System C. The Hetch Hetehy Aqueduct delivers water directly to the system^ customers. The Hetch Hetehy system (0.13 mfl - 0.24 mfl) is fed by the Calaveras Reservoir (110 mfl) and the San Antonio Reservoir (0.46 mfl). Portions of System C are also supplied by three treatment plants (0,03-2,1 mfl) and local runoff and wellfields whose asbestos content was not measured. The well and runoff water receives no further treatment which would, reduce its asbestos content. Given the natural asbestos content of the different source waters, the variability In asbestos content in the treated waters and the distinct possibility that Intermittent "slugs" of untreated high asbestos content w ater may have been delivered directly to System O by any number of sources, any asbestos levels observed in that system clearly are subject to wide variation regardless of the pipe material. The inability to control for such an important confounding factor clearly renders meaningless any conclusions regarding the role of A/C pipe in contributing asbestos to the drinking water. Further, the limited number of water samples also raises serious questions about - 12W 8W * 7557 the paper's observations. An EPA funded report on asbestos sampling in the San Francisco Bay Area comments on the problems of such limited sampling, as well as the previously mentioned likelihood of asbestos level variability! The individual asbestos fiber concentrations listed in previous sections of this report (Kanarek et al samples) are the values ji for a single grab sample of tap water taken from a census ' tract. Water sampling sites were chosen on the basis of 1) being representative of a specific water distribution system It oanhdara2c)terctoenffvetnhieenacsebeostfossacmopnltienngt. of Itnheosredewratteor smyostreemfsu, lliyt i may be necessary to sample a small proportion of 1 very large How of water...This would minimise the problems of utilizing I grab samples and reduce the number of water samples to be analyzed. This would also take Into account the interm ittent and notv^iform occurrence of asbestos in water from various source8.l3~(ernohasia added). 1 ` Finally, in the 1950's and 1960's substantial amounts of asbestos caulking rope were used with lead caulked valves and fittings. This rope is in contact with the water and could convelvably contribute asbestos to water in the distribution system. J $ I -13- 7558 VH. AGREEMENT WITH OTHER DATA Interpretation of data should have coherence i.e. the results of a study are suspect If they conflict with findings from other studies. In this regard, the paper is in serious want of corroboration. Nothing In the extensive body of literature produced on the subject of potential fiber release from A/C pipe makes findings comparable to those made in this paper. The results of an independent study conducted by one of the Bay Area's largest water utilities actually contradict the paper's findings and hypothesis. , TABLE 2 SYSTEM X COMPARISON OP ASBESTOS LEVELS IN WATER BEFORE AND AFTER CONVEYANCE THROUGH A/C PIPE Sample l-Treated Water Tap W>at*ve>r*1? 2-Treated water Tao Water2 Alkalinity 2H {tm fL. CaCO-.) 9.38 20 9.38 19 8,09 103 8.08 103 Calcium Hardness (rmr/L CaCO-j) 8.8 8,8 35.9 38.7 Chrysotile AI Asbestos (f/L.) 12.21 BI>L 12,20 BPL 12.14 BDL 12.16 BDL * Conveyed through approximately 1700 linear feet A/C pipe. 2 Conveyed through approximately 2000 linear feet A/C pipe. -w>avrnrTTHg.r*iMrtilli'imnr..-MW,*: -14r,A iiidd&Mmim The paper discusses the "unusual" water chemistry of System C and theorizes that the high pH may be unduly and falsely weighting the AI towards nonaggressiveness. The authors also note the low calcium content of the water suggesting this may account for the apparent asbestos increases. A comparison of System. X (Sample 1) with the mean water quality values for System C follows; TABLE 3 COMPARISON OF WATER QUALTTY SYSTEM C AND SYSTEM X (SAMPLE 1) Sample System 0 System X (Sample 1) Alkalinity pH (mg/1. CaCOf) 9.2 53,2 9.38 20 Calcium Hardness (mir/L. CaCO^) 23,05 8,8 AI Before 11.93 12.21 After 12.54 12.20 Table 3 shows that both the alkalinity and the calcium hardness of Sample 1 are considerably lower than that of System C -- a worst case scenario, if you will. Yet, Sample 1 demonstrates no asbestos pick up end no Increase in AI as the water traverses the A/C pipe system. Although this is a limited comparison, these observations cast serious doubts over the hypothesis that the low calcium content of the water in System C explains the purported asbestos Increases. 75G0 ,?^ l M a ^ a g S S a g S f f l ^ g y ^ v n . CONCLUSIONS The paper suffers from numerous weaknesses and errors. Its underlying assumption is fallacious -- there is not, nor was there ever Intended to be a positive correlation between the Aggressiveness Index (AD and fiber release from A/C pipe. The original study's design, by its own admission, is of limited relevance to A/C pipe. The sampling procedure was extremely limited and did not generate independent "before/after" pairs. The most important test statistic is incorrectly calculated. Important confounding variables are overlooked or ignored -- others are dismissed out of hand without explanation. Finally, the results have not been replicated or corroborated by other studies and are inconsistent with more contemporary knowledge on the subject. -.18. 7561 REFERENCES 1. Kanarek, M. S,, Conforti, P. M,, and Jackson, L. A,, "Chrysotile Asbestos Fibers in Drinking Water from Asbestos-Cement Pipe," Environmental Science and Technology,. VoL 15, No. 8, August 1981. 2. Cooper, R. C., Kanarek, M., Murchio, J., Conforti, P., Jackson, L., Callard, R., and Lysmer, D,, "Asbestos In Domestic Water Supplies in Five California Counties," Progress Report for Period April 25, 1977 to June 30, 1978, U.R. ,? Environmental Protection Agency Contract No. R 804368-02, EHS Publication No. 78-2, 1978. y 3. Kanarek, M, S., "Asbestos in Drinking Water and Cancer Incidence," Pii.D, dissertation, Department of Epidemiology, University of California at Berkeley, 1978. s 4. Cooper, R, C., Kanarek, M., Murchio, J., Conforti, P., Jackson, L., Callard, R., and Lysmer, D., "Asbestos In Domestic Water Supplies in Five California Counties, Part II, 1969-1974, Population and Tumor Data Base," UJS. Environmental Protection Agency, Contract No. R 804366-02, EHS Publication No. 79-1, 1979, s., 5 Kanarek, M, Conforti, P. W., Jackson, L., Cooper, R. C., and Murchio, J. O Ji C., "Asbestos in Drinking Water and Cancer Incidence In the San Francisco Iti1 i <i -17- 7562 Bay Area," American Journal of Epidemiology. 1X2:54-72, 1980, vjv 6. Contort!, P, M,, Kanarek, M. R., Jackson, L. A,, Cooper, R, C., and Murchio, J, C., "Asbestos in Drinking Water and Cancer Incidence in the San Francisco Bay Areas 1969-1974," Journal of Chronic Diseases. 34:211-224, 1981. 7. American Water Works Association Standard for Asbestos Cement Distribution Pipe, 4 In. Through lfl In., For Water and Other Liquids, AWWA C-400-77,1977, . 8. American Society of Testing and Materials, Standard Method of Testing Asbestos-Cement Pipe, ASTM C-500-76, 1976. 9. Schock, M, R,, Logsdon, G. S., and Clark, P, J,, "Evaluation and Control of Asbestos-Cement Pipe Corrosion," paper presented at -the International Corrosion Forum, National Association of Corrosion Engineers, 1981. i 10. MfUette, J . R., Direct Testimony at Public Hearing on Proposed Addition to Section 19-13-B102 of the Connecticut Public Health Code, September 16, 1980. 11. Op. f i t . (Schock) 12. Schock, M, R. and Buelow, R. W., "The Behavior of Asbestos-Cement Pip Under Various Water Quality Conditions; Part 2, Theoretical Considerations," Journal American Water Works Association. December, 1981, -18- 75 G3 ^ r.aafe^L^rfy^v^ia^if ^.>1*1^ ^.^jnfi ift^ mw^ la^triirSuTali^ ih^sfi^t.i^aft*r t^nr,f*^ .w t f fcattft.rf&^iirfsrti, v ^ tiwai $4 9 15. HoycV> T>. H,, "Structural Performance of Asbestos-Cement Pipe In Corrosive Potahle Water Environments," paper presented at the Internatlonl Corrosion Forum, National Association of Corrosion Engineers, 1981. 14. Op. Clt. (Kanarek, 1978) 15. Tarter, M. E,, and Leong, C. J., "Asbestos Sampling Plan for the San Francisco Bay Area, California," U.S. Environmental Protection Agency, Order No. C3253NAET, July, 1980, 16. Op. Clt. (MiUette,1980) IT. Snedecor, G. W, and Cochran, W. G., Statistical Methods - Sixth Edition, Iowa State University Press, Ames, Iowa, 1987. 18. Op. Clt. (Tarter) 19. Op. Cit. (Tarter) -19- 75 G4 Recomrneridal Work Radioes forA/C Pipe \ 'in Contents In tro d u c tio n ........................................................................ 2 Asbestos and Health ............................. ; .................. 3 Summary of OSHA Asbestos Standard .T rr................... 4 Products and Operations.............................................. .5 Recommended Work Practices Shipping, Receiving, Handling and Assembly............... 6 Cutting A/C Pipe Carbide Blade Equipment...............................................7 Snap Cutting Equipment............................................... 8 Machining A/C Pipe Field Lathe--M anual...................................................... 9 Field Lathe--Pow er...................................................... 10 Rasp--M anual............................................................... 11 Cutting Holes in A/C Pipe Shell Drill Cu and t t e r s ................................................................. R asp............................................................... 12 13. Chisel and R asp ........................................................... 14 Tapping A/C Pipe Non-Pressure .......................................................... ...15 Pressure ........................................................................ 16 Coupling Removal........................................................... 17 Housekeeping and Waste D isposal................................ 18 Non-Recommended Work Practice Cutting ^ A brasive D is c - D r y ..................................................................... 19 i i /*M*yyrgh4 1977 by AJC Pipe Producers Association Introduction The Occupational Safety and Health Act In the United'? States and similar laws in Canada and other countries wereill enacted to ensure so far as possible, every worker a safe and $ healthy work place. This legislation is far-reaching, it cov-'.^j ers millions of employees and nearly every employer, in- 1 eluding those involved in utility duct and pipeline construe- 1 tion. in keeping with the spirit and intent of these laws, the asbestos-cement pipe industry is cooperating with labor by disseminating information regarding the potential hazards of exposure to airborne asbestos and themeans of reducing such potential hazards through good work practices. Good work practices is what this booklet is about. The recommendations that appear on the following pages are the result of field testing and were developed through study,* They are intended as general guides to achieve safe and clean job site conditions when working with asbestoscement (A/C) pipe products. Since field conditions will vary, adherence to these work practices will not necessarily, guarantee compliance with national, state or local regula tions. Questions relating to compliance should be directed to appropriate regulatory agencies, The A/C Pipe Producers Associationbelieves this booklet will be helpful to engineers, superintendents, contractors, foremen and laying crews in understanding and explaining established procedures for the safe handling of A/C pipe products. "Sec "Asbestos Exposures During ihe Cutting and Machining of AsbestosCement Pipe/' report prepared by Equitable Environmental Health Inc., March, 1977mi "News from TAC/' reporting on a survey by the Occupational Asbestos and Health _ , ,T ;6u'are aware, airborne asbestos fiber has been idenas a possible health hazard. Very few things to which ^Iw e'.are exposed are "zero risks." But like the automobile, `Svf'eiectncity and x-rays, there are non-harmful ways to use potentially harmful things. Generally, asbestos-cement (A1C) pipe products contain less than20% asbestos. The asbestos fibers are not free, but encapsulated or "locked-in" the cement binder like rein forcing rods in concrete. The distinction between "free" and "bound" asbestos is extremely important. First of all, it determines the probability of fiber release, which in turn, directly relates to the probability of risk. More importantly, it explains clearly and simply why A1C pipe is a nonharmful use of asbestos. Experience has shown that minimizing exposure to air borne asbestos dust is the only effective method of prevent ing asbestos-related diseases. Recommended work prac. tices are the best assurance of providing exposure safeuards for yourself and your employees. . ------- Summary of OSHA Asbestos Standard The Occupational Safety and Health Act was signed ntq| law on December 29, 1970, and became effective on April-/1 28, 1971. On December 7, 1971, the Secretary of Labor,| issued a temporary standard for exposure to asbestos dust. As required by the Act, a permanent standard for asbestos l exposure was promulgated six months later. .'is Under the current standard, it is the employer's respon- jij|l sibility to assure that exposure of employees to airborne concentrations of asbestos fibers does not exceed the fol lowing "permissible exposure levels": a. Eight hour time weighted average: Two fibers, longer Ilian 5 micrometers, per cubic centimeter. b. Ceiling concentrations: Ten fibers, longer than 5 mi crometers, per cubic centimeter. In October, 1975, OSHA proposed a revision to the cur rent standard which would reduce the eight hour time weighted average exposure to 0.5 fibers per cubic centime ter of air and ceiling concentrations to 5.0 fibers per cubic centimeter. In their notice, OSHA stated that a separate "construction industry standard" would be issued to cov workers who handle asbestos-containing products. This? work practice booklet will be revised as necessary to reflect any changes the construction industry standard may necessitate. The work practices recommended in this booklet are based on data for "peak dust concentrations" representing short time periods ofmaximum exposure. Fieldcutting and machiningopera- lions involving AIC pipe are normally infrequent and of short duration. Using these recommended work practices, it is improba ble that field personnel would be exposedin a typical working day to levels exceeding the eight hour time weighted average. Products and Operations fWes'pf A/C Pipe Products covered by these work practices Include: / / C l a s s " Pressure Pipe 'Ife!,V<Transmission'' Pressure Pipe ^33"^ Pressure Sewer Pipe Gravity Sewer Pipe Building Sewer Pipe Storm Drain Pipe Perforated Underdrain Pipe Electrical Conduit Telephone Duct Air Duct Operations to which these work practices apply include: Shipping, Receiving and Handling Cutting Machining Hole Cutting Tapping Coupling Removal Housekeeping and Waste Disposali ii ^ Shipping, Receiving, Handling and Assembly' |||f ggajtiyi'.' * Cutting Carbide Blade Equipment ' . , "" ' X ' ---------- \ ^ X m t f d d IR r i; *. r J . y d L A ." ' -r / , V i?- \m r . . "J (V.i^!] ((;'))! \ W ' V i ,V 1. M A ')$ I. / A L :l, A/C pipe is shipped dean from the factory and carefully loaded using methods acceptable to the carrier. Loading, unloading, stringing out and assembling A/C pipe are essentially dust-free operations. Even in enclosed spaces, airborne asbestos fiber levels from pipe handling operations aie far below existing and proposed occupational standards. All hand and mechanical unloading operations should be car ried oui in accordance with the manufacturer's installation man uals. A/C Pipe Products: All Size Range: All ' --Bw. '.: - C 1 v \X / / Blade cutlers consist of a frame adjustable to the circumference of the pipe and a number of outboard, self-tracking rollers that align one or more caibide-tipped cutting blades. Blade cutters are typically hand-operated. Due lo the relatively low mechanical input and clean culling action, significant amounts of airborne asbestos dust are not produced. A/C Pipe Products:'All Size Range: 3" through 24" Cutting Snap Cutting Equipment Machining Field Lathe-Manual Snap cutters or "squeeze and pop" equipment operates by means of cutting w heels mounted in a chain wrapped around the pipe barrel.' Hydraulic pressure, applied by means of a remote electric or manually-operated pump, simultaneously squeezes the cut ting wheels into the pipe wall until the cut Is made, A1C Pipe Products: All Size Range; Pressure Pipe--3" through 24" Pressure, Gravity and Building Sewer; Storm Drain; Air, Electrical and Telephone Duct--3" through 36" Manual field lathes are designed to end-trim and re-machine rough pipe barrels to factory-machined end profiles. The lathe consists of an adjustable, self-aligning arbor Inserted into the pipe bore (which acts as a mandrel upon which the turning handle operates), a screw-fed turning frame, carbide machining blades and manual (hand or ratchet) turning handles. A/C Pipe Products: All Size Range: All Machining Field Lathe-Power r i ifffW IjtfrdiM iJ . Machining Rasp-Manual* Power field ladies, like manna) lathes, are designed to end trim and re-machine rough pipe barrels to factory-machined end pro files. The1lathe consists of an adjustable, self-aligning arbor in serted into the pipe bore (which acts as a mandrel upon which the turning handle operates), a screw-fed turning frame, carbide machining blades and electric or pneumatic power drive. A1C Pipe Products: All Size Range: All n.J * 1 i ' ` "u r f 'A j 'i V u *, Short lengths of A1C pipe (MEE's & MOA's) can be cut for pipe closures, repairs and to locate fittings exactly. Field cut ends may be rebeveled with a coarse wood rasp to form a taper approximat ing the same profile as the factory-beveled end. A 1C Pipe Products: All Size Range: All l t Hole Cutting Shell Cutters K'' *1 v . \ / >,<* s A "; [ \ \ f ri-T A i I /` MMul1"-1 p i '1, | Hole Cutting Drill and Rasp* // / , / ( :Y; I *,i| 'fJ/ - , " ' .. . v ' / ::// For field connections into A 1C pipe, clean, even entry cuts may be accomplished by means of shell cutting equipment. Shell cutters consist of a hole cutter housing mounted on the pipe, a carbide or diamond-tipped hole cutter and a manual ratchet, pneumatic, electric or gasoline drive to power the cutting head. When culling holes in A1C pipe products, all dust and cuttings should be removed from lhe pipe or duct interior after the cutting operation. Rlmhov.i I may be accomplished by flushing with wa ter, wet mopping or vacuuming prior to placing in service. DO NOT BLOW OUT W1T11COMPRESSED AIR OR DRY SWEEP. A1C Pipe Products: Pressure, Gravity and Building Sewer; Air Duct Size Range: All Field connections may be made with a heavy duty electric drill and rasp. Using a carbide-tipped drill, a series of closely-spaced holes are first drilled around the hole outline. The disc Is knocked free with a hammer and the edges of the hole are dressed with a coarse wood rasp. When cutting holes in A/C pipe products, all dust and cuttings should be removed from the pipe or duel interiorafter the cutting operation. Removal may be accomplished by flushing with wa ter, wet mopping or vacuuming prior to placing in service. DO NOT BLOW OUT WITH COMPRESSED AIR(OR DRY SWEEP. A/C Pipe Pioducts: Pressure, Gravity and Building Sewer; Air Duct Size Range: All Hole Cutting Chisel and Rasp ..,-- --''iw ifra iiiiii. Tapping Non-Pressure Holes may be cut into A 1C pipe with a hammer and chisel. The edge of a plumber's wood chisel is used to cut completely around the hole oulline,`ab outa Vi" from the prescribed line. The opera tion Is repeated and the cut deepened until through. The edges of the hole are then dressed with a coarse wood rasp. When cutting holes In A/C pipe products, all dust and cuttings should be removed from the pipe or duct interior after the cutting operation. Removal may be accomplished by flushing with wa ter, wet mopping or vacuuming prior to placing in service. DO NOT 131.0W OUT W1T11COMPRESSED AIR OR DRY SWEEP. A/C Pipe Producls: Pressme, Gravity and Building Sewer; Air Duct Size Range: Alli Non-pressure or "dry" lapping for service connections may be performed in or above the trench. The equipment is affixed to the pipe by means of a chain yoke. Separate drills and taps or a combination tool drills and taps the pipe wall. Corporation stops or other connections may then be affixed to the pipe. To minimize (a) Ihe fouling of valves, regulators, meters, etc. with drips and (b) unnecessary addition of asbestos lo di inking water, all dust and cuttings should be removed from the pipe Interlorby flushing with water, wet mopping or vacuuming prior to placing In service. DO NOT BLOW OUT Wi l l I COM PRESSED AIR OR DRY SWEEP. ' 1 A/C Pipe Products: Pressure Pipe Size Range; All i ivnr>*m*data not cuuentlv available. RCivn'nendatkinbasedon exposure data Tapping Pressure* Coupling Removal Hammer and Chisel* \ ` T, (IV 0/.1 'V ( x \:\ . , x \ V i' A y ' 4 4 4 /t S ' 1 , M i J . .. H y ,, ' ' SV )4 > ' 1 4 h -X ' Pressure or "wet" tapping for service connections is performed in the trench while the pipe is under pressure. The equipment (manual or power driven) is affixed to the pipe by means of a chain yoke. A combination boring and inserting bar drills and taps the pipe wall and inserts a corporation stop or pipe plug. The pressure chamber, which protects against water leakage, also catches the asbestos-cement chips, so this is essentially a dust- free operation. , To minimize (a) the fouling of .valves, regulators, meters, etc, with chips and (b) unnecessary addition of asbestos to drinking water, provisions should bo made for riownslreanvflushing or use of tapping equipment with positive purge or "blow-off" features. A/C Pipe Products: Pressure Pipe Size Range: All ............ .............. Replacement of damaged pipe necessitates excavation, exposure and removal. Coupling removal may be accomplished by gradu ally splitting the coupling lengthwise, u sin g achisel and ball-peen hammer. After the top of Hie coupling has been split, a cru wbar or similar too! is used as a lever to split the bottom uf tire coupling. A1C Pipe Products: All pipe with A/C couplings Size Range: All I I ("""'^cposuri! d a ti nut currently avattabt Kecommendatiori based an uxi'nsure data A/C Pipe Producers Association REGULAR MEMBERS Asbestos de Mexico, S.A. Tlalnepantla, Mexico Atlas Asbestos Company Montreal, Quebec, Canada Canadian Johns-Manville Co,, Ltd, Mississauga, Ontario, Canada Cement Asbestos Products Company Birmingham, Alabama Crtain-teed Corporation Valley Forge, Pennsylvania Johns-Manville Sales Corporation Denver, Colorado Mexaiit del Norte, S.A. Mexico City, Mexico ASSOCIATE MEMBERS Amiantus Dienst Export Hamburg, Germany Asbestos Monterrey, S.A. Mexico City, Mexico Association de l'Industrie l'Asbeste-Gment Nyon, Switzerland Eternit, B.V, Amsterdam, Holland Everitube Neuilly-sur-Seine, France James Hardie &c Company Pty., Ltd. Sydney, New South Wales, Australia Hellenit, S.A". Athens, Greece Hyderabad Asbestos Cement Products Ltd. Hyderabad, India Paraisten Kalkki Oy Pargas, Finland Sociedad Industrial Pizarreo, S.A, Santiago, Chite TAC Construction Materials, Ltd, Manchester, United Kingdom