Document NG0avva0YOkwwNek7JVnv0eKb

Draft; Final Eeport SUPPLEMENTAL ANALYSIS OF THE TECHNOLOGICAL FEASIBILITY AND ECONOMIC IMPLICATIONS OF A r . 1 FIBER PER CUBIC CENTIMETER EXPOSURE LIMIT FOR ASBESTOS Contract Numb? j-9f-6-234 Psr@pard ot% Occupational Safety aad Haltfa. t - Admini str&tion I U. S. Department csf Labor Washington, D. C. 20210 i: Prepared by: CONSAD Research Corporation 121 NorA Highland Avenue Pittsburgh^ Pennsylvania X5206 Slaytea Environmental CossnU&st* 2as< 14 Mf If?? CRMC-M&S-002736 r~ i TABLE OF CONTENTS UQ EXECUTIVE SUMMARY 2.0 INTRODUCTION 3. 0 ASSESSMENT METHODOLOGY 3. 1 Technology Assessment 3.2 Assessment of Potential Substitute 3 3 Economic/Market Assessment 4*0 OVERVIEW CONSIDERATIONS 4 1 Technologic! Feasibility 4Z Substitute for Asbestos 4.3 Asbestos Industry Market 5.0 PRIMARY ASBESTOS SEC :,iENTS S A9btosCmeat Pipe 5.2 AsbesUss-Cemeat Sheet*. Shingles and Sidings 5 3 Friction Material 5.4 Viayl-Asbestos Floor Tile 5.5 Reinforced Plastics 5.6 Paper Prefect 5.7 Gaskets, Seals and Packings S.i Faints, Coatings and Sealants f Asbestos Textiles 6. IMPLICATIONS QF A 9. S FIBER/CC EXPOSURE LIMIT ' &e i Qptism 1: Reduce Exposure Through Engineering ad Work Practices 6 Z Option 2: Substitute for Asbestos 5.3 Option 3: S^sritch to CompetitiveProduct# 6.4 Option 4: Abandon Asbestos Product Line 2*S. 1.1 2.1 3. 1 3.1 3.3 3.5. 4.1 4.1 4.11 4.17 5.1 5.1 5.21 5.35 5.48 5,58 5.65 5.81 5. 93 5.193 4.1 4.2 4.5 4.10 6.13 I CRMC-M&S-00273 7 TA3X-E OF CONTENTS (continued) Appendix A Ca# History of Substitution for Asbestos Product* - Calcium Silicate Molded lasulstioa Appendix 8 - Materials Evaluated m Potential Asbestos Substitutes Appendix C Case Study f Potassium Titaaate Fibers f a & Substitute for Asbestos AiissI ^i UST OF TABLES 4. S Unique Characteristics of Asbestos 4oZ Asbestos Fiber Prices: 1970 sad 1977 4.3 United States Asbestos Fiber Usage * 1974 4.4 Estimated if74 Sales for Asbestos Industry # 5 I Reported and Projected Asbestos Fiber Concentration.# - Asbestos-Cement Pip 5.2 Water and Sanitary Sewer Price and Market Estimates 5 3 Reported and Projected Asbestos Fiber-Concentrations - Asbestos-Cement Sheets S4 Major A/C Sheet Sub-Markets: Sis, Competitive Products aS. Market Position S5 Reported and Projected Asbestos Fiber Cnceatratieas - Friction Materials 5.6 Reported and Projected Asbestos Fiber Concentrations - Vinyl-Asbestos Floor Til 5 7 U.S. Asbestos Paper Market 5 8 Reported and Projected Asbestos Fiber Concentrations - Asbestos Paper Products 5 9 Reported and Projected Asbestos Fiber Concentrations - Packing sad Caskets 5 IQ Packing and Gasket Sub-Markets: Sale, Competitive Products and Market Position 5 11 Reported and Projected Asbestos Fiber Concentrations Paints, Coatina and Sealant ' 4. IE 4,13 4,18 4.19 5.9 5.15 5.27 5, 32 S40 5.53 5.66 5. 75 5# 86 5.88 5.99 III CRMC-M&S-002739 UST OF TABLES (continued) 8012 Reported and Projected Asbestos Fiber Concentrations Textiles Dry S 13 Reported and Projected Asbestos Fiber Concentrations - Textile Wet *. Ill 112 I* CRMC-M&S-002740 1.0 EXECUTIVE SUMMARY The National Institute of Occupational Safety and Health has recommended a 0.1 fiber/cc TWA expo cure limit and a 0. 5 fiber/cc celling exposure limit be set as permissible limits for asbestos ex posures in the work place. Accordingly, the Occupational Safety and Health Administration COSHA} contracted CONSAD Research Corporation ts conduct a supplementary analysis of these lower exposure limits with regard to the feasibility of control and economic implications to affected industries. Emphasis was also placed on determining potential substitutes for asbestos and competitive products. A parallel, yet extremely important change was to evaluate the feasibility of monitor ing asbestos exposures at the 0. 1 fiber/ec level. CONSAD subcontracted this investigation to Clayton Environmental Consultants who else evalua ted the technological feasibility of controlling asbestos exposures. It Is Clayton's judgment after a careful review of: l) currently attain&ble .and reported exposure level, and 2! advancing control tech nology and related rodue&oas la exposure levels, that the primary asbestos industries can generally comply with a 0.2 fiber/cc timeweighted average {TWA) exposure level, but not a 0S 1 fiber/cc level, using both the best application of techniques now available and nearly developed technology likely to be implemented within the next two years. 1.1 CRMC-M&S.002741 The exception to this Is the dry-woven textile segment where exposure i . levels cannot b reduced below !0 fiber/cc without major breakthrough in sew processing technology Where this kind ci breakthrough has r L occurred In the textile segment -- development of the "wet" process [ used by one of tho asbestos textile manufacturers -- exposures can n be reduced to levels consistent with iha 0*2 fiber/cc projected limitation. The determination that 0.1 fiber/cc exposure level is not techni- ally feasible even by application of best available technology rests largely on careful evaluation of the likely background level in primary asbestos industries (other than dry woven textiles) In these plants, raw liber is being received, stored, and handled and finishing ope ra tions are being conducted with manual mater ials-handling procedure. In such instances, the ubiquitous nature of asbestos in such facilities i. as a result of worker carelessness, control system malfunction, in r advertent spillage, and less-fchaa-perfect work practices will result in a finite background fiber concentration upon which even slight TWA L exposure elevationo -- mainly in the fib. r handling and finishing ' C opera!loss -- will yield isSgrat4 TWA exposure* on the order of . I to 0.3 fiber/cc. Therefore. It I b contractor's judgment that even the best applications f known control measures including exemplary work practices point to feasible, realistically achievable TWA expo sure level for asbestos In the primary Industry segments (other than dry L woven textiles) of 0*2 fiber/cc for asbestos fibers greater than five L microna in length. !' 1.2 CRMC-M&S-002742 In evaluating the potential of replacing asbestos in product lines, it is evident that there does sot exist one material that can be used in all asbestos applications as a substitute. In most instances, the materials evaluated for these applications are more expensive than asbestos and would require some modification of the manufacturing process. Furthermore, significant cost and performance penalties may result from a switch to non-asbestos materials. Nevertheless, theret exists a significant research aad development effort in the asbestos industry to find suitable replacements for asbestos. Presently, there Is a well-defined trend to substitute other materials for asbestos ta reinforced plastics with over 50% of the reinforcement of phenolic molding compounds provided by non-asbestos substitutes. In the floortile segment, manufacturers rn.ro running trials on a new cellulose fiber to be used in place sf asbestos. An intense research and development effort is ongoing la this country to replace asbestos in friction materials and some success has been reported. Fiberglass is most commonly reported material being evaluated t replace asbestos in certain paper and textile applications. Additionally, newly developed synthetic fibers fe.g.9 AramMs. Ceramics, Graphite) may also play some role as asbestos substitutes; howeverB their evaluation must be considered on a product-by-product basis. Replacing asbestos in cement products of A/C pipe and sheets, is under heavy research investigation with 1.3 CRMC-M&S-002743 sew r same success reported 1b England and Japan using alkali-resistant glass. However, little is reported in the U. S. on the use of this i. material in domestically produced cement products. Competitive products also will play a role is the event of reducing r . the exposure limit to 0.1 lbcr/ec. As the exposure limit is lowered, r the probability increases that using an asbestos-containing product will be subject to OSHA regulations, la certain instances, whore a competitive product performs on a comparable cost/performance basis as asbestos products, some end-users may well be forced to switch r to other products rather than face governmental restrictions. There fore, In cases where asbestos-containing products exist in very com petitive markets, OSHA regulations and their ancillary requirements r-w for monitoring, medical survaillance, showers, etc. may make these L products less attractive and thus cause a decline in their relative r market share. t this tread continues for any given product, certain asbestos applications may cease to exist. I r f . 1.4 CRMC-M&S-002744 L..J * ' isew .1 I I j- j 2.0 INTRODUCTION Oss December 13, 1976, the National Institute for Occupational Safety and Health (NIOSH), made a recommendation to the Occupational Safety and Health Administration (OSHA) that no worker be exposed to an airborne concentration of asbestos in excess of ICO, 000 fibers over S am te length per cubic meter on an 8-hour time-weighted average basis {I.#., 0. i fibsrs/cc). In addition, the proposed recommendation states that no worker should be exposed to peak concentrations in excess of 500,000 such fibers per cubic meter of air based on 15-minute sampling periods (i,e., 0,5 fibers/ce) To date, OSKA has formally proposed reducing asbestos exposures In the workplace to 0,5 fibers/ cc TWA and a 5 fiber/cc peak exposure limit. In July 1976, CONSAD Submitted its final report on the technological feasibility and inflationary impact of the 0,5 fiber/cc exposure limit. The purpose of the report to follow is to conduct a supplemental analysis of affected industries Involved with asbestos in order to determine the technological feasibility e reducing exposures to 0,1 fiber/ce and to assess the economic impli cations of such an action. The technological feasibility analysis focused on three major areas of concerns determining further engineering control to reduce asbestos exposures; identifying potential areas where a change In the 2,8 CRMC-M&S-00274S I toMtoftMKei fli 's manufacturing process may be anticipated to control exposures, and; assessing the feasibility of accurately monitoring asbestos exposures at these low limits, i,e>, 0.1 fiber/cc. Another major effort not covered adequately in the previous TFA/XIS for asbestos was an evalua tion of the possibility of substituting different r~ aterials for asbestos In Hi manufacturing process or other products for asbestos containing product To these ends, potential substitutes are identified and their relative merits cost, performance, availability are discussed as compared to asbestos products. Finally, an attempt was made to evaluate die overall economic implications of further reducing exposure limits to 0.1 fiber/cc if it is feasible to attain. However, it was not in the scope of this study to determine the industry-wide cost of compliance with a 0. 1 fiber/cc exposure limit, nor to evaluate the economy-wide inflationary impacts associated with such a recommendation. This document is Intended to provide sound data bass upon which the feasi bility of monitoring and controlling asbestos exposures at 0. 1 fiber/cc can be evaluated and to Identify the potential for replacing asbestos in many of its product applications. For the most pa?t, this report focuses aa the major primary asbestos Industry segments. Chapter 3,0 briefly discusses the contrac tor*# methodology for the technological, substitution, marketing, and monitoring assessments end generally describes overall data gathering 2*2 rarsv* CRMC-M&S-002746 procedures and major sources of information. Chapter 4. 0 presents an overview analysis of technological, substitution and market consi derations common to most segments. Chapter 5. 0 is presented on a product-specific basis corresponding to the nine major industry segments identified in the previous TFA/IIS for asbestos. These include: Antes tea-cement pipe; e Asbestos-cement sheets, shingles and siding; a Asbestos friction materials; Vinyl asbestos floor tile; Asbestos reinforced plastics; Asbestos paper products; Asbestos paints, coating and sealants; Asbestos gaskets, seals and packing materials; Asbestos textiles. Each these major product categories contains a background discussion concerning the products, the feasibility of engineering con trols. a discussion of material substitutes and competing products, and an analysis of the economic implications that may result from lowering the asbestos exposure limit. Chapter 6.0 consolidates the most impor tant points brought out in the product-specific discussions in Chapter 5. 0 and broadens the focus to evaluate the overall implications of the 2.3 CRMC-M&S-002747 recommended exposure limit of 0.1 fiber/cc. The feasibility of moni toring and accurately counting asbestos fibers in the workplace environ ment la presented in Chapter 7, 0* Included are alternatives to the present phase-ccatrast microscopic method and a review of pertinent asbestos exposure date to determine the accuracy and precision of the NIOSH approved monitoring method. Appendices are provided at the end of the report to emphasise and document discussions in the major tot. 2.4 CRMC-M&S-002748 * 3. 0 ASSESSMENT METHODOL OGY 3.1 Technology Assessment The assessment of technological feasibility with reference to the NSOSH-proposcd 0. 1 fiber/cc exposure level comprised updated infor mation gathering and compilation and evaluation on a prod'ict segmentby-segment basis. Updated existing data obtained from CONSAD/ Clayton's TFA/HS for the 0. 5 fiber/cc exposure limit included a multi level investigation covering: l) an updated literature review, 2) direct inquiries - telephone interviews and visits - to selected asbestos indus tries, and 3) selected plant visits. Because this study supplements the earlier, comprehensive analysis with reference to the proposed 0. 5 fiber/cc level, primary focus has been placed on the conception, plan ning, and application of control methods in the intervening time period since the first study. At the same time. It must be recognised that the evolution and implementation of control techniques in the pri mary asbestos industries -- engineering methods, process changes, equipment substitution, and work practices -- represent a continuum of advancing technology, largely void of major "breakthroughs. " This occurs in large part because the workplace asbestos standard has been a "moving target" at which Industry has been aiming over a period of several years. Thus, even the increasingly better application of well- S.I -rrn*7T> CRMC-M&S-002749 known, proven control methods on a more consistent, exacting basis has resulted in steady, sometimes dramatic decreases in airborne asbestos fiber concentrations in many industries. The assessment methodology, accordingly, has depended largely ob CONSAD's and Clayton's continuing interaction with the asbestos industry. Specifically, an attempt was made to identify those organiza tions who: 1) were likely to know of or be Applying "best technology," and 21 have extended cooperation and demonstrated interest to the extent that plant visits and critically-meaningful dialogue short of on site visits would help to indicate current trends with respect to advanc ing control technology. The most useful documentation for the assessment of technology has been the opportunity in several instances to see firsthand, and relate simultaneously, recently-measured exposure levels with actual operations at representative work sites. This on-site observation and assessment of the various operations, including the nature and extent of local and general controls and work practices, has also proven, in tha contractor's Judgment, to be extremely reliable information. Daring dies# visits and in the course of continuing discussions with industry representatives, several innovative and adapt*.** control techniques have been identified that, taken together, define the frontier ef advancing technology for controlling asbestos in ths workplace. i 3.2 CRMC-M&S-002750 n These techniques are identified and described in Section 4.0 as they Impact the various major product lines in the primary asbestos indus tries. Two initial processing steps common to most major segments of the primary asbestos industries -- fiber receiving/storage and fiber introduction -- are treated initially in an overview discussion that precede the detailed segment-by-segment analysis. 3.2 Assessment of Potential Subrs*titutes To obtain data a the potential for substituting other materials for asbestos, several approaches were utilized. First. CONSAD con ducted a retrospective computer search of major informa tional data files. These files included: NASA 1962 - current; . NASA Technical Briefs; Market Abstracts 1972 - current; Engineering Index 1970 - current; WTXS 1970 - current; Chemical Abstract Condensation Applied Section Volumes 69-8$; and MieeeUMeeua data bases. The output from those files for the most part included citations and abstract of references. Promising sources were categorised by 3.S CRMC-M&S-002751 product segment and attempts were made to obtain copies of complete items. Much of the literature was from foreign sources that could not easily be accessed; however, some of the abstracts provided useful information The second approach involved telephone interviews with industry personnel; those people associated with the asbestos industry; the manufacturers of substitute materials and other knowledgeable sources. From these conversations, CONSAD solicited information on material substitutes, their application, avaliability and cost information on pro ducts that compete with asbestos -containing products and finally their judgment concerning the economic implications of a 0, 1 fiber/cc exposure limit for asbestos. A third method utilized to gather information and data was to conduct m limited number of on-site interviews with asbestos industry research and development and marketing representatives. Meetings have bees conducted with the Asbestos Information Association, Johns-M&m'villa Corporation, Baybesfces-Manhattan Corporation, and Seadix Corporation. It is believed that the information that the contrac tor has been able to gather from these various efforts represent a thorough search of the possible substitutes for asbestos in these major product segments. A major difficulty In obtaining this Information is that a groat deal of the research and development work to find suitable 3.4 W,- - T* /--t CRMC-M&S-002752 substitutes for asbestos is being conducted by the manufacturers of asbestos-containing products, and due to the competitiveness of the market, specific data is proprietary and confidential. 3.3 Economic/Market Assessment is order to determin the economic implications of a further reduction sf the asbestos exposure limit to 0.1 fiber/cc as recom mended by NZOSH, an analysis of the various markets in which asbestos products compete was undertaken. This work can b considered an extension and refinement of CONSAD's economic study conducted for the proposed 0.5 fiber/cc. Major markets have been more carefully defined and further divided into sub-markets of the nine major product segments of the primary manufactures of asbestos products. To these ends, information was obtained on the size of these sub-markets in terms of their consumption of asbestos fiber, sales volumes and/or units of material sold. Additionally, products which compete with asbestos products were identified and aa attempt made to determine the market shares of tibe major competing products, including asbestos-containing Ites, Th above information was obtained from a variety of sources, including: Producer ef asbestos products; Trade associations for asbestos products; 3.S 'TT*T CRMC-M&S-002753  Trade associations for noa-asbestos products; * Producer of non-asbestos products; Trad periodicals; 19?2 Census f Manufacturers CU.S. Department of Commerce^; e Marketing Study of Asbestos Industry, Ministry Industry and Commerce, Government of Quebec, (done by Sores Znc, and A, D, Little of Canada, Ltd. ). Existing trends in share of market were identified for some sub market* where asbestos products and non-asbestos products compete. Prices of asbestos products and competing non-asbestos products are indicated. Trends la share of market are also presented for domestic sales and imports in industry segments where asbestos product imports are a significant force, i.e., the asbestos textile industry. Addition ally, relative prices of domestic and Imported asbestos products are delineated. Information concerning trends in share of market and price data was provided by the following sources: Producers of asbestos products; o Trad associations; Building >4tstrue<don Cost Data (R.S. Means Company); Asbestos magazine. mm*# 3.6 # ti CRMC-M&S-002754 0 ,, Trade associations for nou-asbcstos products; o Producers of non-asbestos products; e Trade periodicals; 1972 Census of Manufacturers (U.S. Department d Commerce); ,, Marketing Study of Asbestos Industry, Ministry Industry and Commerce, Government of Quebec, (done by Sores Inc, and A, D. LitUe of Canada, Ltd, ) Existing trends in share of market were identified for some submarkets where asbestos products and non-asbestos products compete. Prices asbestos products and competing non-asbestos products are indicated. Trends la share of market are also presented for domestic sales and imports in industry segments where asbestos product imports &m a significant force, i.e., the asbestos textile industry. Addition ally, relative prices of domestic and imported asbestos products are delineated. Information concerning trends in share of market and price data was provided by fife following sources: Producers of asbestosproducts; Trade associations; Building Construction Cost Data (R.S. Means Company); Asbestos magS'-:*a* 1.6 CRMC-M&S -002755 '( ' An attempt was made to determine the price sensitivity of pre sent asbestos-containing products as a method to qualitatively evaluat ing what effect the increased cost of compliance for QSHA stands would haw on the continued economic viability of the product. For the most parts this information was obtained from conversations with the major producers of asbestos products. However, in the water and sewer pipe market in which asbestos cement pipes compete, consulting engineers, municipal water works personnel were contacted for their input. Finally, in order to put into prospective what overall implications would result from an imposed 0.1 fiber/cc asbestos limit, a brief discussion is presented on the effects of m rigid enforcement of toe current Z fiber/cc in end-use applications, i. e., toe construction industry. To these ends, information was obtained from producers of asbestos products, construction industry officials and OSHA's TFA/ OS on toe proposed asbestos exposure limit for the construction indus try. 3.7 * CRMC-M&S-002756 *% 4.0 OVERVIEW CONSIDERATION'S 4 I Technological Feasibility This section of the report present an overview of the technolog ies! feasibility analysis for fee primary asbestos industry segments fey Clayton Environmental Consultants* Within each segment-specific section la Chapter 5. 0, the information crucial to technological feasi bility is organised in fe following manner: Review of Process; Current Controls and Work Practices; Reported Exposure Levels; Currenily-iicSaicvsMe Exposures; Future Controls Under Development; and Projected Lowest-Achievable Exposures Before beginning fee segment-specific analyses for fee primary asbes tos Industrie, it is helpful to first cover two important processing step common to all segments, "fiber receiving and storage" and "fiber introduction. " 4. 1. Fiber Receiving and Storage The startfag pofat f as valuation of control measures and their impact on exposure levels in fee primary asbestos industries must begin wife consideration of fee significant characteristics of a critical. 4.1 w*rwfrf CRMC-M&S-002757 , 'mSM^i1 ,!* is y wirsHjn. ii.iih esen>wwwsi n i 111. i --_ ,0` t industry-wide pre-processiny operation: fiber receiving, warehousing, storage r4 staging Because this functional operation is common to mil of the asbestos industries where raw fiber is introduced in a manu facturing process, this discussion applies to all segments, as does the following discussion on fiber introduction. Asbestos fiber is currently transported in a dry state by rail cars or trucks and contained in paper or plastic bags as palletised ship ments. At a plant operation, this material is unloaded manually or, more ofiaa, by powered forklift trucks. The palletized cargo is brought to a raw-fiber warehouse for intermediate storage before being distrib uted to a staging area(e) within the plant operations near the fiber intro duction work statiofjfsjs Spillage from these raw-fiber containers -- in the rail car or trailer. In the warehouse, or in any portion of the plant -- adds signif icantly to the exposure levels. This occurs not only to the warehouse men or truck operator who transports the fiber, but also to other persons in the plant subjected to the ubiquitous, background presence of asbestos as It may be spread throughout the plant or entrained by pedestrian or vehicular traffic. This background level becomes increasingly significant with reference to the very low fiber levels of Interest, such as 0. I, 9.2, r even 9.5 fibr/cc. Background levels alone can equal or exceed these concentrations without preventative 4.2 CRMC-M&S-0027 5 8 M f, r. *s steps to avoid spillage, to vacuum any spillage, and to otherwise suppress fiber reentrainment from floors on a general basis. Accord ingly, It Is extremely important to avoid tearing, ripping, or damaging th rsbestos bags r containers during shipment, unloading, stacking, and unetacking, and transport within the plant operations. Current Controls and Work Practices Several currently available practices and techniques are used increasingly to avoid asbestos-bag damage. These include inflatable dunnage, Uaed rail ears, palletized loading, shrinking film wrapped pallets, and double-sealed bags. Consistent, routine taping of broken or tom bags and vacuuming within the shipping cars prior to unloading are critical t minimize exposure to the warehousemen, to workers at fiber introduction, and to meet lew plant-wide background levels. AH spills subsequent to unloading must be vacuumed promptly to avoid elevated caposure in both the receiving and warehouse areas and in the fiber Introduction step after damaged bags have been staged. Bulk shipments of compressed asbestos pallets and Kraft-paperwrapped high-demsity blocks are available from selected suppliers. The high-uemsity block of asbestos -- which produces less dust in receiving and warehousing -- Is? suspected to be used more widely as one of several process modifications to minimize fiber emissions now produced during bag opening. Application will become more widespread 4.) CRMC-M&S-002759 e techniques (or fibcrising the deneified raw fiber continue to be developed in several product lines* Reported Exposure Levels A limited survey of several primary asbestos industry segment.*, plus a review of recently-published exposure levels, show the timeweighted average (TWA? asbestos exposure in receiving and storage to rang widely from 0,1 to 2. 5 fibers/ec. Even the lowest reported levels have been achieved with less than full-scale application of effective, currently available control measures. Currently Achievable Exposures If the control methods and work, practices outlined above are implemented routinely, Clayton believes the TWA exposure levels for unloading, storage, and transport raw fibers can be maintained con sistently below 0. 3 iiber/ec. This will requires 1. Repair of damaged containers; 2* Immediate clean-up of spillage and floor accumulation of asbestos-containing solids; and 3<* Floor cleaning at least once per shift with a power- vacuum unit -- preferably combined with wet floor cleaning. Future Control Methods Under Development Additional control measures now being developed, in addition to wider usage of high-density fiber blocks, include improved packaging (general movement toward plastic bags}, stronger pallets, standardised 4.4 CRMC-M&S-002760 rvr i7 minimum number of else lor bag, and improved transportation prac tices. Projected Lowest-Achievable Exposure Clayton believe, on the basis of judgment and currcntly-attainabl exposure levels, that asbestc exposures in the fiber receiving and storage pre-processing stages can, within about two years, be controlled consistently below 0. Z fiber/cc if the same level of progress demonstrated in the past two years can be maintained. 4. JL 2 Fiber Introduction fc addition to fiber receiving and storage, another processing step common to all primary asbestos industries is the introduction of raw fiber into the process. Because this step is functionally similar la most of the major product lines, the assessment of technological feasibility is addressed here, prior to the segment-by-segment analyses. Th most significant difference in processing technique with reference to fiber introduction among the various segments is the degree to which the raw fibers must be opened or "fiberixed" in the Initial stages of processing. This fiber-opening effect is achieved by techniques known a "milling", "wiilowing". "fluffing", "blockbusting", "boating" and 'hydropulning". The significant difference among these techniques requirements or product-specific processing -- will r > ! f 4.S f r; S a.y n CRMC-M&S-002761 definitely affect the degree and timing of use of hi^h-dcnsity raw-fiber consumption in the various operations. For example, the "Points, Coatings and Sealants" mixing process requires a very high degree of fiber opening, often denoted as "fluffing". This is accomplished much more readily when the raw fiber is introduced to the process in a rela tively uncomp&cted state. On the other hand, the use of high-density blocks of raw fiber finds best application, under currently prevailing practice, in the papermaking segment of the industry, especially when hydropulpers, as opposed to beaters, are used to mix and homogenise A wet-stock batch prior to the paper-forming operation. Current Controls and Work Practices The fiber introduction step currently takes place almost exclu sively by manual bag-dumping methods, although semi-automated bagdumpiag stations for fiber introduction are being t?ied in a few instances. Th primary advantage of automated bag-dumping is the distance and degree of physical enclosure separating the worker loading the con veyor-fed equipment from the bag opening per se. Although it appears very likely that automatic bag-dumping stations will eventually be used on a widespread basis, there is no documented evidence as to the addi tional protection afforded the worker by this method. Nevertheless, judgment suggests that semi-automated bag-dumping would help lower exposures at fiber teiroducUoa better than the best designed and venti lated manual dump stations. 4.6 i t . Uir CRMC-M&S-0027i The fibsr-iatroductioii processing step is accomplished in cur rent operations largely by the use of evacuated, hooded dump stations with enclosed empty-bag receptacles contiguous to the dumping hoods, hut also kept under negative pressure, Is. the "Paper" segment, how ever, palpable kraft-paper hags can be added to the wet blending oper ation without & hag-emptying and drying operation. A similar bag-tobatek addition situation occurs in the "Floor Tile" segment where polyethelene containers are compatible with both the process mixing operation and product quality, thus eliminating the need for manual bag emptying and dry-bag disposal. The use of semi-enclosed local exhaust ventilation represents the ms't important control method applicable to worker protection at the fibor introduction step. When a worker empties a bag manually by slitting, shaking, and/or dumping within a semi-enclosed dump station (kept under negative pressure), the disposal and related handling of the bag becomes paramount with reference to exposure level. The newer generation bag-dumping hoods have an empty-bag receptacle incorporated within the evacuated enclosure so that several empty bags can bs accumulated and then removed in semi-sea led containers to suitable larger disposal receptacles. This technique is proven and and currently available, but needs to be used on a more routine basis zh,Mm. at present la order to achieve the lowest attainable fiber exposure levels. 4,7 CRMC-M&S-002763 1, Adequately exhausted fiber Introduction enclosures which contain facilities for proper disposal of empty bags; Z0 Regular performance checks and preventative main tenance on local exhaust systems; S Immediate clean-up of spillage and floor accumulation of asbestos-containing solids using central vacuumcleaning systems; 4 Floor cleaning at least once per shift with a powervacuum unit -- preferably combined with wet floor cleaning; and 5c Mechanically^ supplied, confemijxaat-free make-up air (tempered relative to ambient conditions) in sufficient volumetric flowrates to balance the combined local exhaust capacity in a given work area. These measures,, together with the consistent, exacting application of control measures described above, would, in Clayton's judgment, achieve exposure levels consistently below 0.4 fiber/cc on a time- waighted average basis for bag-opening, fiber introduction operations. Future Control Methods Under ^velooment Additional control measures mow feeing developed, in addition to wider use of high-density fiber blocks and somi-automated dumping stations, include recyclable bulk containers and reinforced bag construc tion. The use of bulk fiber shipments with closed, automated, pneu- nafcic conveyance represents another promising concept now in the first stages of development. . 4.9 ------- -------------------------------- ~-- CRMC-M&S-002764 Pro jected Lov/t-st - Achievable Exposures Although 111 fiber introduction step has been very troublesome, historically, with respect to control of worker exposures, an exacting application f hooded, manual bag-dumping stations, with integrated entity hag collection and the maximum, increasing use of high-density fiber blocks and process-recyclable containers should, in the con tractor9 Judgment, allow a consistent maintenance of TWA worker exposures below 0,2 fsber/cc within about two years. 4. 1.3 Engineering Control Costs In the current, supplemental analysis, we have identified only two newly-available control techniques that need to be considered as ascremesta! costs necessary to achieve TWA asbestos exposures of O- '& flber/cc. These include the 1) semi-automated bag-dumping station that will be widely used for the fiber introduction step and 2} a new pemto r -drivea mobile floor cleaning unit that incorporates wet acrubbing together with v&cuulnmg. Although these two techniques are wow being introduced, their incremental benefits have not yet been documented with reference to worker exposures to asbestos. Never theless, their us# suggests gam added benefit in maintaining exposure levels &lw @2 fifeer/ec The machinery required for the bag-opening station costs $15, 000 plus an additional $75,000 to installation costs (labor and materials) 4.10 `tv CRMC-M&S-002765 according to Johns-Manviilc Corporation. For future systems. the contractor estimates tiiat the total installed costs would be approxi mately $40,000 per station. The cost for the new mobile unit ($11,000) is not markedly different from the dry sweepers cited in the previous TFA/IIS. It is not believed that these costs will significantly change the control costs estimated earlier to achieve 0. 2 fiber/cc. 4. 2 Substitutes for Asbestos At the ctset it should be pointed out that there does not presently exist a substitute material that is able to replace asbestos in all of its major product applications. Substitute materials are available for many applications, but they may not match asbestos materials on a strict cost/perfomsaace basis is many instances. Historically, asbes tos has been an extremely versitil fiber able to impart reinforcement, best and chemical resistance to various products. The unique proper ties of chrysolite asbestos fibers are briefly outlined in Table 4. 1. Many factors have encouraged the search for suitable substitutes for asbestos for many years. These factors include: Significant price Increases for asbestos (See Table 4.2); Significant world-wide shortage of asbestos fiber; Concerns regarding the health effects of exposure to asbestos; 4.11 ------------------------------*------'-- ----------------------------------------TTT---------------------------------------------------- ' '*"* ' ' r CKMC-M&S-002766 TABLE 4.1: Unique Characteristic* of Asbestos Property Alkali resistance Fine Fiber Diameter High Teneile Strength High Impact Resistance Temperature Resistance Surface Charge High Modulus of Elasticity Fiber Characteristics Diepeasibility Cert Comment Attack only occurs at extremely high concentrations and temperatures. Provide many reinforcing fibers per unit weight. 300,000 to 500,000 psi depending upon test method and particulate source. Not brittle and will not degrade readily in length upon processing. Good; brittle at high temperatures; temperature at maximum ignition lose, 1800 F. Positive - provides chemical bond to many mediums, i. e., asphalt. Approximately 12-ZO million psi. Curly and flexible which is beneficial in forming characteristics in manu facturing process; alto interlaces when formed into sheets and paper which enhances product strength. Readily dispensible in aqueous slurries. Provides low cost/performance or eost/physicial property ratio. Source: Jetsas-MaBviH Corporatise 4.12 *7W, &% CRMC-M&S-002767 TABLE 4.2: Asbestos Fiber Prices: 1970 and 1977 19 VC Price/ Ton*' 1977 Price/ Ton^ A/C Pipe A/C Sheet A/C Shingles and Siding Disk Brakes (FM) Segment Lining |FMJ Vinyl-Asbestos Floor Tile Latest Sieet Underlayment $218 $184 $113 $184 $ 73 $ 42 $137 $561 $434 $269 $434 $146 $100 $299 Commercial Paper $113 $269 Reinforced Plastic Roof Coatings Sheet lacking Beater-Add Gasket S $ 60 $ 54 ' $184 $184 $130 $112 $434 $187 Asbestos TextUse $425 $1093 Pc re Chan 157 136 138 136 100 138 118 138 117 107 136 2 157 *Add $14*16 for freight to Northeastern areas. 2Add $30 for freight to Northeastern areas. *Grsde of fiber changed. Sourest Johns-MaavilU Corporation. 4.13 rswrw, r-----T-Terr > / CRMC-M&S-002768 . Health concern* regarding the use of certain asbestos containing products (i,c., drywall spackling compound): Administrative burdens Imposed by OSHA's current standard for occupational exposure to asbestos; OSHA's October 1975 proposed amendment to the asbestos standard (i. e. , 0. 5 fiber/ec exposure limit); Increased workers' compensation costs; Increased Incidence of common law product liability rats; . Increased difficulty in obtaining product liability insurance coverage; and Increase Is advance publicity regarding health effects of asbestos. The above factors are illustrative of the incentives which industry has had in recent years to And substitutes for asbestos even without the added impetus of a 0,1 fiber/cc exposure limit* The development of adequate asbestos substitutes is a painstaking, lengthy and costly undertaking for industry; however, it is evident that a major research and development effort is presently underway to find suitable replace ments in products where it is both technically end economically feasible. To delineate some of tike difficulties encountered in actually substituting other materials for asbestos is a major product line. Appendix A pre sents a case study of Johns-Manvilla's success in developing a aoaasbestoa molded insulation product. It has been emphasised tbnt even though valuable knowledge may be gained by the manufacturer in a successful search for as asbestos substitute, it is not necessarily 4.14 11 CRMC-M&S-002769 transferable to other product applications* It may be fair to say that the research and development efforts to replace asbestos will bo as unique as the individual production and product/performance require ments* As stated previously, the following Chapter 5,0 is organized by major product segment. For each of these major asbestos-containing products, the potential of material substitution for asbestos in that particular application is reviewed as determined by industry research and development. Due to the competitiveness of the Industry, much of the specific detail on actual material compositions and costs is pro prietary, and unavailable. However, general comments can be made. Additionally, Appendix B lists the various materials and fibers reported as potential substitutes for asbestos. For each material the potential product applications are listed as reported by the literature and industry sources. Cost comparisons and general performance comments arc also given. This listing is not intended to be comprehensive, but taken with the discussion of substitutes in Chapter 5.0 for each major product, a fair interpretation of the potential for replacing asbestos in certain applications can be gained. A final general comment on substitutes, la CONSAD's many conversations with members of the asbestos producing and user Indus try, b of their major concerns is that other materials or fibers 4.15 / CRMC-M&S-002770 considered os adequate asbestos substitutes will themselves have adverse health effects. A case in point is the introduction of potassium titanate fibers in 1971 by Dupont, tradename FYBEX, as a replacement for asbestos in reinforced plastics and possibly friction materials. However, in 1974, Dupont withdrew this material from the market because it showed signs cf being potentially hazardous to man. Appendix C is a brief accounting of the development of FYBEX fibers, its potential applications and general toxicity as related to CONSAD by Dupont. In the international community, a three-pronged study into the cmrsiacgesic activity of man-made mineral fibers used in industry as asbestos substitutes, is being undertaken by the International Agency for Research ca Cancer (Lyon, France). Physical similarities between the man-made fibers and asbestos have led the European glass-fiber and textile industries to ask LARC to carry out epidemiological studies in 70 factories ia IS countries, laboratory studies on animals and fiberdust measurements in manufacturing plants. The results of this study have not yet been reviewed. (1) As important as the evaluation of poten tial health hazards for asbestos substitutes seem to be, it should be emphasized that this type of evaluation is not within the scope of the present study. CONSAD has reported on items that were uncovered in the course of investigation, but has not actively researched die poten tial toxicity of identified substitute materials. 4.16 %W,*"Tr CRMC-M&S-002771 4. 3 Asbestos Industry Market In order to gain a perspective on the relative size and importance oi the major segments of the primary asbestos industry, asbestos fiber usage fey product category are presented in Table 4.3, For consistency the product categories are listed in the same order as in the previous TFA/IXS study conducted for the 0. 5 Eber/cc standard. The data given is for 1974a However, it is reported that the consumption levels for 1976 are very similar to these amounts with the exception of joint cements and reinforced plastics which have decreased significantly due to substitution efforts. Additionally, Table 4. 4 presents an update of overall segment sales for the primary segments of the asbestos industry. These figures are for 1974 and, in some cases, represent a refinement based on more recent data of the sales information than those presented in the TFA/QS. 4.17 r'sy-7*gr f fV o CRMC-M&s- i TABLE 4.3: United States Asbestos Fiber Usage - 1974 t* Tons Percent of U.S. i <. r A/C Pipe Consumed 139,000 Asbestos Usace 16% i. A/C Sseet, Shingles and Siding 52,000 i; Friction Materials 55.000 6% 6% ? Vinyl-Asbestos Floor Tile 110,000 13% Reinforced Plastics 18,000 2% i . Paper Products 330,000 38% r1. Faints. Coatings, and Sealants . (65, 009 C&S * 13, 000 joint 78,000 cement^ 9% Caskets, Seal and Packing 29,000 l Taaddles 12,000 ! Misceifaaaetts T@tol 53.000 176.000 3% 1% 100% Note: The asbestos fiber consumption levels for 1976 are very similar to 1974 levels, except the fiber consumption for joint cements and reinforced plastics has decreased considerably, due to [_ *wbsdilution for asbestos. Sours? Johns ^ManviU Corporation i 1' 4# IS i ... ........ . ,, TABLE 4*4: Estimated 1974 Sales for Asbestos Industry: Primary Manufacturers and Secondary Fabricator* (in millions) Primary Manufacturers Secondary Fabricators * A/C Pipe A/C Sheet. Shingles and Siding Friction Materials Vinyl-Asbestos Floor Tile Reinforced Plastics Paper Product Paints, Coatings sssd Sealants Gaskets. Seals and Packings Textiles $250 $ 60 $300 $260 $120 $1422 $275 $134 $ 40s $ 53 $294 $340 $280 $162 ^Secondary processors or fabricator* represent those firm* that pur chase products from one or more segments of the primary industry and either fabricate these materials (for example, cutting and drilling of cement sheet) or process them together with other materials for incor poration into an end products ^Dollar estimates tor this market generally does not reflect actual sales transactions. Approximately three-fourths of this market repre sents captive, intra-company sales. For example, Armstrong Cork, GAF Corporation, and Congoieum produce 85% of all American latex sheet flooring and transfer this production to themselves to make resil ient sheet flooring. ^Approximately one-third of this market does not reflect actual sales, bat ratter intra-company transfers of asbestos textiles to make friction materials. Source; US 0.5 fiber standard, CONSAD Research Corporation and conversations with industry officials for revisions of A/C Pipe and Gaskets. Seals and Packings estimates. 4.19 CRMC-M&S-002774 v REFERENCES FOR CHAPTER 4.0 1. Chemical Week. September 29, 1976, page 33. 9 4,2 */ * CRMC-M&S-002775 5.0 PRIMARY ASBESTOS SEGMENTS 5. I Asbestos - Cement Pipe S.1.1 Background Information Asbestos-cement (A/C) pip was developed in Europe in response to the need for an anticorrosive, high pressure pipe to carry seawater for firefighting purposes. Introduced into the United States market in 1929, asbestos-cement pipe is currently used to convey potable water under pressure, and for non~pressure applications such as drainage of storm water* sewage and other types of liquid wastes. Other uses include electrical conduit and vent pipe. Pipe fittings can also be manu factured from asbestos cement. Standard pipe sizes range from 2 inches to 36 inches la diameter but asbestos-cement pipe can be made in diameters up to 80 inches. The points more or less common to all asbestos-cement products are strength, resiliency, flexibllty, durability, inertness and fire resistance. Asbestos plays a major role in all of these characteristics. In pipe* asbestos imparts a flexural strength which allows a certain amount of deflection without failure. The laminar structure of the pipe which results from the basic method of manufacturing also contributes to greater strength. Because of the nature of the rzw materials used to manufacture asbestos-cement pipe it resists corrosion and most 5.1 ;i". -; # --ttTr-------- CRMC-M&S-002776 `I I* i. L !* chemical action and is not subject to electrolysis. Ease of installation and the integrity of joint are valuable properties of pipes made from this material. Formulations for asbestos-cement pipe are determined by the type of curing used in the operation and by the quality and types of raw materials used. In the United States, curing of the product is accomplished in a short time in an autoclave. The autoclave process m* akes use of silica to react with free lime as it is formed and thus speeds up the rate of hydration of the cement. In other countries, where curing is carried out under moist conditions at ordinary temper atures, silica is not required. Representative formulation ranges are shown: Autoclave Cure Normal Cur* Asbestos Cement Silica 15-23% 42-53% 54-40% Asbestos Cement 15-25% 75-35% A/C pipe h.s won considerable acceptance as a high pressure water pipe. Xn 1974, more titan 50 million lineal feet cf A/C water pipe was sold in the U.S. for the 4" to 16" standard water pipe size. Industry sources estimate that over 50% of all A/C pipe made goes Into water pipe applications. Non-pressure sewer pipe represents the second major market for A/C pipe. According to Johns Manville estimates, 55% of all A/C pipe Is sold in the sanitary sewer market 5.2 CRMC-M&S-002777 KHgsWSS'SSK* with the remaining usages distributed over a wide range of asbestoscement pipe products* The consumption of asbestos fibers for the enti* A/C pipe market including water and sewer pipe application wz.s approximately 139.000 tons in 1974 or 16% of total U. S. fiber con sumption. Next to asbestos papers, asbestos cement pipe ranked second in overall domestic fiber consumption. 5.1.2, Technological Feasibility Review of Process Basic raw materials used for the production of asbestos cement (A/C) pipe include asbestos fiber, portland cement, silica sand and water. After fiber introduction to the process (see Section 3.1.1), conveying equipment carries the raw fiber to a dry mixing step. Agita tion in this step serves two purposes: opening or fluffing the fiber, and mixing the cement constituents. Sand and portland cement are added at this point, typically being conveyed pneumatically to an enclosed, live-bottom mixer. The dry mix next passes by conveyor to a wet-mixing operation just upstream of the pipe-forming machine. The wet mortar flows to the pipe-forming machine vats, where the asbestos cemsnt slurry is picked up on a rotating, screened cylinder mold and transferred on a traveling belt over suction boxes, where as a wet mat It is wrapped os a mandrel. Wrapping continues to attain proper thickness. Pipe 5.3 CRMC-M&S-002778 /*V'~ :rriv i: L r ) { { j *- i i * j i' % actions art generally east in 10- to 15-foot lengths. After an initial setting time, the pipe is stripped from the mandrel, then air cured, and final cured in an autoclave using saturated steam. Cured pipe sections are then transported to the finishing opera tions. Here the pipe is cut to uniform lengths and machined in a variety of ways - sawing, lathing, drilling, and outfitted with a coupling. To eaeure a.tightly-fitting pipe joint, the ends of the pipe sections are machined smooth; such finishing is carried out on a lathe. The finished pipe is inspected, and each section of "pressure pipe" (pipe used for conveying water under pressure) is tested hydro statically. In addition to full and partial lengths, pipe plants also produce a variety of standard and special fittingi. Pipe coupling Is the most widely-used fitting. To mate with the machined pipe, inside surfaces of the coupling must ho grooved to hold a rubber seel. Other fittings (tees, elbows, reducers, etc,) are produced on a less-frequent schedule. Most pipe plants alee produce specialty fittings sad pieces on an individual basis. Operations required for fittings production Include sawing, drilling, machining, boring, and bonding. Some specialty applications require pipe lengths machined over their entire length; this Is accomplished with a lathe. 1.4 -- CRMC-M&S-002779 I % Current Controls and Work Practices Fiber lost to the work environment at the dry-mixing stage is controlled by maintaining negative pressure inside the mixer -- itself an appendage to a local-exhaust dust-control system. The mixer generally receives and dispenses raw material by screw conveyor. Local exhaust is also employed at the wet-mixing operation. Introduction, of the dry mortar into the mixer and initial agitation until the solids become wet produce the dust at this step. Once the mortar becomes wet. little additional fiber becomes airborne. A significant pot-don of the fiber emitted between fiber introduc tion and wet mixing may result from material-handling equipment such as screw conveyors and bucket elevators. Dust control in conveying equipment is obtained through continuous exhaust of hoods and main tenance of negative pressure within the closed mixing equipment. No special control equipment is used during pipe formation, air curing, and steam curing. Nevertheless, good housekeeping is essential at these steps, since spills of mortar or fragments of pipe will dry, ultimately resulting in fiber release due to pedestrian and vehicular traffic. Aside from fiber fatroduefcioa, pipe-finishing machining operations represent the major potential source of airborne fibers in an A/C pipe plant. Extensive local exhaust and hooding must be used near the tool 5.5 Trrrrr CRMC-M&S-002780 /* 0\ cutting surface to capture and control fibrous solids, including chips. The use of single-point cu.ting tools, rather than saws or cutting and machining equipment using abrasion, substantially reduces fiber emis r sions at the finishing step. Control equipment for coupling and fittings production is essenti ally the same as that described for pipe finishing. Local exhaust near the working point of the tool is used to capturo and remove solids. Variability in production techniques and in pipe size make design of ? i- tight-fitting hoods difficult. Reported Exposure Levels Several plant visits, plus continuing correspondence and phone interviews with industry representatives, together with a review of recently-published exposure levels (1, Z, 3), show the time-weighted i. average (TWA) asbestos exposures in asbestos cement pipe plants to range widely from 0. 1 to 4.8 fiber#/cc, In Clayton's judgment, however, even A lower reported levels have generally been achieved with lessthan-full-scale, optimum application of currently-available, proven control measures and work practices. Currently Achievable Exposures Available, proves control measures and work practices which could be used sow to better advantage to assure low exposure levels Include the rigorous application of well-known methods, such ast 1.4 C-RMC-;YJ&S -002781 . i? 1. Regular performance checks and preventative maintenance on local exhaust systems; 2. Immediate clean-up of spillage and floor accumulation of asbestos-containing solids; 3. Floor cleaning at least once per shift with a power-vacuum unit -- preferably combined with wet floor cleaning; and 4m Mechanically-supplied, contaminant-free make-up air (tempered relative to ambient conditions) in sufficient volumetric flowrates to balance the combined local ex haust capacity in a given work area. These measures,, together with the consistent, exacting application of control measures described above would, in Clayton's judgment, achieve exposure levels consistently below 0.4 fiber/cc on a time- weighted average basis for asbestos cement pipe operations. Future Controls Under Development Wet mixing immediately after fiber introduction is being used in at least one cement pipe plant. This process modification precludes any mixing and thus eliminates one potential source of fiber loss to the work environment. Advancing control technology for reducing exposure to asbestos in fits finishing operations includes redesign of machinery with inte grated local exhaust. Standard milling equipment and machinery with minor modification have been used in pipe finishing. Significant reduc tion is worker exposure could be achieved if the machinery were re assigned for Improving dust capture. 5.7 vrrrrrriv CRMC-M&S-002782 Wet machining ha been used at some areas in the A/C pipe finish ing and fitting production, and development work is underwm/ to deter mine if: X. Wat suppression can be adapted to the pipe lathes; and 2. Wet finishing reduces the fiber release at this processing stage. Considerable automation could also be incorporated eventually in machinery redesign, thereby reducing employee exposure. Project Lowest Achievable Exposures Tightening of ft* materials-handlicg equipment between fiber introduction, dry-mixing and wet-mixing processes, and/or use of immediate wet mixing will further reduce the background fiber concen tration near those areas in a plant. Systematic reduction in background fiber levels should reduce exposure at the pipe formation and curing steps to below 0.2 fiber/ce or less. Implementation of latest-available equipment will result in further exposure reduction in the finishing area. Exposure should be control lable to within 0.2 fiber/cc range by use of closely fitting local exhaust systems designed specifically for each individual unit. Table 5.1 pre sents reported and projected asbestos fiber concentrations for A/C pipe processes. S.B ,,r*r ---Tinrrv 1 *3 *, i\ " CRMC-M&S-002783 TABLE 5* Is Reported and Projected Asbestos Fibs? Concentrations* Asbestos Cement Pipe Frocess-Related Work Areas TWA Ash lOS CxpOSU rc Level (fibers/cc) Reported Range Currently Achievable Projected Lowest Achievable Fiber Receiving & Storage 0.2 - 2.5 0.3 0.2 Fiber Introduction Dry Mix - Wet Mix 0.1 - 4.8 0.4 - 3.0 0.4 0,4 0.2 0.2 fipt Fornation 0.1 - 1.4 0.3 0.2 AlrCure/Autoclaving 0.2 - 0.3 0.3 0.2 Saving 0.1 - l. 0.4 0.2 Finishing Laches <0.1 - 0.? 0.4 0.2 Coupling Cutoff St tlacbining 0.2 - 2.3 0.4 0.2 Fittings & Specialties 1.5 - 2.1 0.4 0.2 Drilling levorfc Sav & Crushing <0.1 - 0.5 2.0 - 2.9 0.4 0.4 0.2 0.2 1 Floor Sweeping <0.1 - 0.3 0.3 0.2 Quality Control Inspection <0.1 - 0.2 0.2 0.1 5.9 # # vwfwfwr* f CKMC-M&8-002784 t 5. 1*3 Potential for Material. Substitution Asbestos has been used as a mlcroreinforccmcnt fiber for cements and concretes for many years. Even though the section deals with asbestos -cement pipe, the potential for material substitution can be discussed in the context of other asbestos cement products as well, ie,, cement sheets. Asbestos is used in cement pipe as a reinforcement fiber impart ing greater elasticity modulus and tensile strength to the cement mix. Jtt is able to withstand the autoclave (heat and pressure) process in the manufacture of the pipe and resists the alkali attack of portiand cement. Other fibers currently considered for use in cement and concrete com posites include steel, glass, alumina, polypropylene, and carbon. Other fibers such as nylon, polyethlene, rayon, rockwool, cotton, acrylic, polyester, and other organic fibers have been considered in tiie pest, but have been ruled from serious consideration due to either high coat, low effectiveness or inadequate resistance to the alkaline cement environment In portiand cement. Similar to asbestos, all of these fibers have relatively high tensile strength (> 50,00U psi). How ever, the moduli of elasticity of the fibers vary from a low of 500,000 psi for polypropylene to a high of over 30 million psi for carbon, steel, and alumina (asbestos has a modulus elasticity of 12-20 million psi). The low modulus (> 10^ psi) fiber (polypropylene) provides improvement in impact strength and ductility of the composite but has little effect on 5.10 "'TP rr? CRMC-M&S-002785 flexural and compressive strength. Fibers having a modulus 10 x 10^ psl usually provide improvement in Impact strength and ductility, as well as in static and dynamic flexural and compressive strength. (4) Other than greater elasticity modulus and an increase in strength of the cement composite, there exist other parameters for successful reinforcement* These are: . Large fiber surface areas; \ , } ' , Good adhesion between cement mix and fiber surface area; Optimum fiber quantity, i. c., as the quantity of fibers increase, the strength of the composite material rises; Greater than critical fiber length (critical length is reached when fibers tear rather than get extracted from tiie matrix; and Aging and deterioration resistance of fibers within the matrix, i*e*. fibers must retain their strength over time from the alkaline attack from cement. A comparison of these micro fibers was tabulated in A/C Under ground ($). an international magazine for the asbestos cement industry, and is presented as follows: m *3 JaZs i Typ of 9 0a** fiber si ti 1 a i U Steel 444 Asbestos 4 4 44 Carbon 444 Glass 444 Organic fibres e < 44 4 44 44 OS s tfe . s s.ii C ritica l j length etl 5a |s < <> 44 44 m tj_) CRMC-M&S-002786 At it evident, asbestos has demonstrated an excellent reinforcing ability, which accounts for its widespread use in pipe and sheet applications Steel fibers have also demonstrated outstanding reinforce ment abilities. However, in thin sheet applications, the cement cover I stay be insufficient to protect the fibers against rust. Carbon fibers have the strength and elasticity, and chemical resistance, yet there apparently exist problems in proper binding within the matrix. More importantly however, is the fact that the carbon fibers are approximately i . 40 times as expetuiive a* asbestos and probably do not represent an economically viable substitute at this time. There has been much research recently on glass reinforcement of cement composites. Although the tensile strength of E-glass is quite high, it is very susceptible to chemical attack from the strong i: alkalis in portiand cement. This phenemonon results in loss of strength with time depending upon storage conditions. (6) The Piikington Class Croup, a member of Fiberglass Limited In England, developed & streoniom (ZIO^) based soda-lime systems which makes a glass signi ficantly more resistant to alkaline attack. This alkali-resistant glass, tradename Cemfll, is reported to suffer little, or no loss of strength ia cement composites with age.(4) In the United States. Owens-Corning has been experimenting with alkali- resistant glass as a substitute for asbestos in asbestos cement pipes and sheets. (7) They have reported S. 12 TTrrr , ,., CRMC-M&S-002787 'm * that at this time, the product is experiencing difficulty in the menu* factoring process and lacks the strength of asbestos cement at the end of the process. To date, they do not have a commercially acceptable product as a substitute for asbestos. Another major research effort Is presently being conducted at Brookhaven National Laboratory and has led to the development of a glass-polymer composite (CPC) sewer pipe. (8) It reportedly may be potentially competitive on a technical and economic basis with pipe now used for non-pressure sewer lines, particularly in the 8- to 24-inch range. This composite is produced by mbriag crushed waste glass (from urban solid waste components) with a monomer (either methyl methacrylate or polyester styrene) and polymerizing by chemical initi ating techniques. Theoretically, in a 1972 market study conducted for Brookhaven by A. D. Little, Inc., it was reported that CPC has techni cal advantages over cement, concrete, and asbestos-cement with its superior acid and chemical resistance. Its low permeability and smooth tight joints. (9) The availability of an adequate supply of waste glass, the principal raw materials for CPC was not well defined, but presum ably a number of government and private programs were to be Initi ated that would generate this material from municipal solid wastes. Possible applications for CPC other than sewer pipe could conceivably be in block brick, wall panels and decorative products. As of this 5.13 T vmrr CRMC-M&S-002788 5 $ writing, Brookhaven is under contract to the Energy Research and Development Administration to evaluate the properties of its glasspolymer sewer pipe. Field testing of full scale sewer pipe sections has been fa progress since 1972. To date no deterioration has been reported. (10) Substitution for asbestos in cement pipe is still in the research and development phases. Alkali-resistant glass may be the most promising material introduced. However, as reported in the literature sad through correspondence with industry representatives, its' performance and adequacy in specific pressure and non-pressure pipe applications have not yet been fully evaluated. 5.1.4 Competitive Products and Market Structure Asbestos-cement pipe competes with a variety of other pipes in die water and sewer markets as evidenced by Table 5.2. The following discussion examines these two markets separately with regard to the acceptance of A/C pipe products. Water Pipe Market Three factors account for the market acceptance of A/C pipe for use in water supply systems. Conventional iron pipe* is corrosive and will emit iron particles into the water system, affecting taste *Cast iron pipe; new product is called ductile iron pipe which presently has 90f of the total iron pipe market. S. 14 T.TtVy-Vff;s-' '* ' /aY,; CRMC-M&S-002789 ="=------'--------- ------------------ CRMC-M&S-002190 m T a b le 3 , 2 i W ater and S anitary Scw ar Pipe P ric e and M a rke t E s tim a te s i l u ( l C U o .K rc t n d trd oI "P * rc Is ::n c n U v uec^ (or u n ita ry icw ar ,'iz; :t,vs p ip e ,} creator then 14". ra th o r than the 3<irc! CONSAD a a lln u U i baaed on conversations with ARM CO Steal C o rp ., Jo h n s-M a n vllle C a rp Loa A ngelas W ater and P o w e r Company, E ast ' y M u n ic ip a l U tility D ta trlc t. T ra n a -T e a and appearance* Corrosion also weakens iron pipe, leading to leaks and eventually breaks. While iron pipe has a quite long expected service life, the non-corrosive property of A/C pipe makes it attractive. Second, A/C pipe is produced with a smooth bore. This provides u low coefficient of friction, thereby helping to keep down pumping costs. Third, A/C pipe has traditionally had a lower per foot selling price than iron pipe. In interviews with operators of i water supply systems who are large purchasers of A/C pipe, CONSAD found that the single most important determinant of product choice is price, except for those limited situations where corre. .on is known to be a serious problem. In spite of its lower selling price per fvut, there are some appli cations for which A/C pipe is considered inferior to iron pipe. In areas where pipes will be subject to quite high pressure (i.e., 150200 psi) in order to maintain adequate pressure at the outlets engineers may opt for ductal iron steel pipe in spite of its cost disadvantage. Until the appearance of A/C pipe, iron pipe dominated the water pipe marked Historically, A/C pipe found it difficult to penetrate the market in the large, older cities of the eastern United States. It has had much greater market acceptance la smaller cities and towns, and In the Southwest and West Coast regions of the country. With the grotr'i* of these areas, A/C pipe has experienced an expansion of sales and increase in its share of the water pipe market. S. 16 *y;,yTWTy. " CRMC-M&S-002791 Around 1961, thin wall PVC pipe was introduced into the water pipe market. Like A/C pipe, PVC pipe is highly anti-corrosive. In addition, PVC pipe has an even lower coeffecient of flow friction than docs A/C or iron pipe, and it is light and flexible. In thin wall applications its current price is less than A/C pipe. At present, thick wall PVC pipe (i.e. , 12" diameter) has American Water Works approval which is generally required for urban areas. It has a price which is comparable to that of iron pipe. Given its anti-corrosive property, weight, and flow coefficient, PVC represents a formidable potential competitor to both A/C and iron pipe in watt* systems. One of the principal competitive advantages A/C pipe has bad over iron pipe is the corrosiveness of iron pipe. In recent years, iron pipe manufacturers have responded to this technical disadvantage by offering polyethelene sheet covered pipe. Such covering adds appro ximately $1 per lineal foot to pipe costs. With the introduction of PVC pipe and the development of polyethe lene liners for iron pipe, the ability of asbestos cement pipe to retain a place In the pressurized water pipe market depends even more heavily than before on its traditional price advantage. As shown Ln Table 5.2. 6" unlined iron pipe is selling for $4. 47/lineal foot, 6" thick wall PVC Thin-wall PVC pipe le presently not approved by the American Water Works for urban areas. f. 17 r.TV,*--f,Tt -------------' ** CRMC-M&S-002 792 t pipe (Jehns-Manville tradename, "Bine Brute") is selling for $3.94/ 1 . lineal foot and 6" A/C pipe sells for $2.49/lineal fc *' CONSAD inter r l. views with users of A/C pipe indicate that if the selling price of A/C [ pipe were to rise to the level of iron pipe or higher, it would lose a significant share of its market and there would be a significant move r ment toward PVC pipe. Additionally, if it were to rise above the cost of of polyethelene coated iron pipe, there would be no significant use in which it would remain the product of choice. It is anticipated A/C pipe's share of the water market will be static in the future. PVC pipe's share c of the market will grow but primarily at the expense of ductal iron pipe. Sewer Pine Mon-pressure sewer pipe represents the second major market for asbestos cement (A/C) pipe. According to rohns-Manville estimates, 30-35% of all A/C pipe is sold in the sanitary sewer market. The impor c tant performance characteristics for sewer pipes are acid resistance, 1 * resistance to infiltration and exfiltration, flow coefficient, and weight per unit length, hi the southern half of the United States, low flow rates due to relatively flat land and high temperatures combine to stimulate c anaerobic bacterial action that produces acid. Because A/C pipe is L subject to acid corrosion, its principal market is in the northern half of the country. In these markets where acid is not a problem, A/C [ pipe competes with vitrified clay, concrete and plastic pipe for use in *i 5.10 9 , CRMc-M&S-002793 *V sanitary sewer systems. (Refer to Table 3.2.) As compared with vit rified clay and concrete. A/C pipe has the advantage forming tighter joints. 2a addition, it is available in longer lengths, thereby reducing the somber of joints and possibility of leaks and infiltration. In the past few years, techniques have been developed to produce plastic sewer pipe in large diameters (8" to 15") where A/C pipe has been most successful in competing with concrete and clay. TRUSS pipe, a proprietary product of Armco Steel, encases a light-weight concrete between walls of; acrylonitrute-bulactient-styrene (ABS). This pipe is highly chemically resistant, rigid, smooth surfaced, available in 12- to 40' lengths and provides very tight seals. Extruded PVC pipe with similar properties is also becoming available in sizes larger than $" in diameter. Offering lower flow resistance than A/C, PVC pipe can be installed at a less steep angle, reducing installation costs. PVC pipe already dominates the small diameter (4M - 6") sewer pipe market. There have been some technical problems of blistering with mass-produced PVC pipe. This has made some engineers shy away from using it. But. assuming the manufacturing problems can be over come, PVC is likely to claim a substantial share of the sewer pipe market in the very near future in which A/C pipe is positioned. Given the technical advantage of plastic pipe for sewer appli cations, long term continued use of A/C pipe requires that it have a lower selling price than PVC or TRUSS pipe. 5.19 --------------------;......... ............ ......... - -------- r*rr-- iV ^ CRMC-M&S-002794 1i 9 In 1977, in western Pennsylvania, prices for 8" sewer pipe were $1. 50/lineal foot for A/C pipe, $1.65/lincal foot for TRUSS pipe, $1.65/lineal foot, $1. 65/lineal foot for PVC pipe, and $1. 50/lineal foot for clay pipe. Clearly, unless A/C pipe price can be significantly reduced relative to the plastic pipe prices, it w*.U eventually be dis placed in the market place* It is anticipated that PVC and TRUSS pipe will take over greater shares of the market for gravity sanitary sewers at the expense of both A/C and clay pipe. 5.20 jr * CRMC-M&S /M 002795 5.2 Asbestos-Coment Sheets, Shingles and Sidings ScZ. 1 Background Information Asbestos-cement products represent the largest market for the world's supply of asbestos. Sheet products have found a variety of uses in the building field including roofing, siding, and bulkheads, curtain wall, cooling tower fill, industrial insulating board and decora tive trim* thsy are available in flat or corrugated sheets. The shingle and siding products are usually textured and painted, but they may also be integrally colored. Sizes range from a small shingle, 12-inches x 24-inches to sheets 4 feet x 12 feet* Thickness of asbestos cement sheet products usually vary from 3/32-inches to 3/16-inches. The addition of asbestos to cement products imparts flexural properties much greater than those of unreinforced concrete. Because asbestos is inorganic and inert it contributes to the durability and fire resistance of these products. Asbestos-cement products are virtually unaffected by the atmospheric environment. Asbestos-cement products can be cured in a short period of time in an autoclave or over several weeks in a moist atmosphere. For autoclave curing silica Is used in the formulation to react with the free lime formed* Product formulations range as follows: 5.2! TW7V CRMC-M&S-002796 c I f L r G r r U Autoclave Cure Normal Cure Asbestos Cement Silica 12-25% 45-54% 30-34% 12-25% 75-88% 1st 1974, the U.3. domestic consumption of rsbestos for asbestos- cement sheet applications was approximately 43, 000 tons, while A/C shingles and siding consumed an estimated 9000 tons of asbestos annu ally, These tonnages represent about 6% of the total U. S. fiber con* sumption. The primary sub-markets in which A/C sheet products compete are: (1) roofing and walling for Industrial buildings, (2) cooling tower fill sheets, (3) corregated bulkheads for canals, (4) laboratory table tops, and (5) the electrical switching gear market. S.2.2 Technological Feasibility Review of Processes Wet-processed asbestos cement sheet production closely paral lels manufacturing of A/C pipe. Asbestos fiber is combined with cement, silica, and water and the sheet is formed, cured, and finished. A "dry" process is also used to make certain shingle-type products. Wet Process Fiber is introduced manually either directly or via conveyor to a dry mixer by bucket elevator and/or screw conveyor. Silica sand and cement are added at this point, anti the solids are mixed until uni form, Such mixing opens the fibers and prepares the mix for wet mix- teg. S.22 / , CRMC-M&S-002797 Wet mixing occurs in a second vessel, where water is added to form a. slurry. The slurry flows into vats from where it its deposited on rotating cylinder molds. A thickened wet mat is formed continuously and transferred from the mold to a moving felt and then to an accumu lator roll. The sheet Is then formed further In embossing rolls or by large hydraulic presses. After initial set and partial curing, it is removed from the press for further curing -- in either heated air or steam-heated autoclaves. After curing, the asbestos cement sheet is sized and trimmed in cut-off saws. To obi*in specified sheet thickness, some sheet products must be sanded to a uniform thickness. Sheet formation operations sometimes include initial fabrication such as dye cutting, punching, or hole drilling. Dry Process The dry process, used for manufacture of some shingle-type products, begins by opening fiber in a hammer mill or similar device and dry mixing with cement and silica. The mixture is metered onto * moving, wetted belt and then passed under compression rollers to remove sir. Water is sprayed on the material and compression con tinues under rolls. Surfece granules can be added before final compres sion and embossing. sat 02798 V Finishing begins with rough tripping and cutting to size after additional air curing. Nail holes may be punched, and die shingles arc cut to exact size. Paint is applied by spraying after final curing takes place. Control Methods and Work Practices As in the A/C pipe segment. paper-bag addition cannot be used to eliminate bag slitting and dumping because of product contamination wife cellulose. Well-applied local exhaust of enclosed mixing equipment and finishing operations represents the most important engineering controls for A/C sheet and related shingle manufacturing. Dry-mix conveying and materials-handling equipment can lose fiber to the work area unless kept thoroughly enclosed and under negative pressure. Wet mortar Itself is not a significant fiber source. Nevertheless, stringent house keeping controls are crucial when handling wet-mixed mortar, for if spillage dries without being removed, pedestrian and vehicular traffic will cause substantial entrainment of airborne fibers. No special con trols are used at the drying or curing steps other than good housekeep ing to minimize fiber release. The degree and adequacy of dust control equipment and work prac tices cover a wide range for cutting, trimming, and sanding finishing operations. Local exhaust with hoods or enclosures are generally used to some extent for major pieces of finishing or fabricating equipment. 5.24 ,J " 1 r 1 ,ul \ - v --r~ : ' CRMC-M&S-C02799 Reported Exposure Levels Several plant visits, plus continuing correspondence and phone interviews with industry representatives together with a review of recently-published exposure levels (1,2, 3} show the time-weighted average (TWA) asbestos exposures in asbestos cement sheet operations to range widely from < 0, 1 to 8.7 fibers/cc. However, even the lower reported levels have generally been achieved with less-than-full-scale, optimum application of currently-available, proven control measures and work practices. Currently-Achievable Exposures Available, proven control measures and work practices which could be used now to better advantage to assure low exposure levels include the rigorous application of well-known methods, such as: 1. Regular performance checks and preventative maintenance on local exhaust systems; 2. Immediate clean-up of spillage and floor accumula tion of asbestos-containing solids using central vacuum-cleaning systems; 3. Floor cleaning at least once per shift with a powervacuum unit -- preferably combined with wet floor cleaning; and 4. Mechanically-supplied, contaminant-free make-up air (tempered relative to ambient conditions) in sufficient volumetric flowrates to balance the com bined local exhaust capacity in a given work area. *.25 r;vv -y--rT ;.r crMc-m&S-oo28oo I These measures, together with the consistent, exacting application of control measures described above would, in the contractor's judgmsnt, achieve exposure levels consistently below 0.4 fiber/cc on a time- weighted average basis for asbestos cement sheet production. [ Future Controls Under Development n Elimination of the dry-mixing operation, as in A/C pipe manu facture, is a promising potential development. Considerable process development work will be required, however, to establish the feasi bility of such a process modification. i: Other likely developments include more automation of finishing operations to eliminate or substantially reduce operator exposure at ?.- t t these typically high-ernission-level operations. Projected Lowest-Achievable Exposures i. Table 5.3 shows the projected lowest-achievable exposures that n can be attained as a result of the exacting application of control methods mentioned previously and the timely implementation of new technology as it is developed^ fa summary, the contractor believes that TWA exposures in the asbestos cement sheet operation can be maintained r consistently below 0.2 jQber/cc within two yeara. 5. 2.3 Potential Sot Material Substitution ?- ! ! As noted previously, asbestos is used primarily for its reinforce i* 1* ment properties ia cemsat sheet applications; however, it also Imparts S.26 i,r*M 11 "V1-1 4( / CRMC-M&S-002801 Tabic 5,3: Reported and Projected Asbestos Fiber Concentrations Asbestos Cement Sheet Process-Related Work Areas TWA Asbestos Exj'*tre Level (ibcr/ce) Reported Range Currently Achievable projected Lowest Achievnble Fiber Receiving A Storage Fiber Introduction 0.2 - 2.5 0.1 - 8.7 0.3 0.4 0.2 0.2 M O Dry Mix - Wet Mix Sheet Fo mat ion/Stripping 0.4 -- 8.4 <0.1 - 3.5 0.4 10.4 0.2 Dry/Care Cat/Trin Send Finishing & Fabrication 0.2 - 2.5 <0.1 - 4.7 <0.1 - 8.0 01 3*6 0.4 0.4 0.4 0.4 0.2 0.2 0.2 0.2 Qaclity Control Inspection <0.1 - 0.7 0.2 0.1 .J 5.27 wow Vw y*! * t '% CRMC-M&S-002802 tI . .! . heat and chemical resistanc* e to boards where such properties are 1 desired. The potential for substitution for asbestos in cement composites j was presented in Section 5. 1 for asbestos cement pipe, but this dis- f - cassias is also relevant lor cement sheet application*. Fibers of Steel. I carbon, glass, ceramics and organic, have been evaluated for these applications, and in some instances, marketable products have been developed. The Ashai Glass Company of Japan has introduced a slate cement ,, board, tradename Suncrete, which utilizes alkali-resistant glass as the * reinforcing agent.(II) The product is reported to be incombustible, water resistant, has good proceseibility and has high impact strength. It still includes 5% asbestos fibers, but that is compared to 12-25% asbestos content of conventional A/C sheets. Another asbestos-free aoB-eombutibic building board is presently being marketed by the Cape Boards and Panels (Uxbridge, England) under the tradename Supalux.(I2) It is reported to be a replacement for the firm's Asbestolux board (containing asbestos) for all fire-resisting applications, such as casing for structural steel work, suspended ceilings, ceiling linings and soffits, fire bricks and fire-resisting particians. There has been a great interest in ceramic fibers recently for various composite applications. Ceramic fibers were developed pri marily for the >mal applications and in some cases have been used as a .5 28 v.'tsyy^r" i* - r/wy..*-- * M" * CRMC-M&S-002803 reinforcing nuturiftl, A* rvportfed by Joln*Manvill*, re*earc!i OR ceramics as a reinforcement for cement resulted in a product with re duced plasticity, reduced strength even at partial substitution and was difficult to process as compared to asbestos reinforcement. However, in thermal applications, it has been reported that the strong market showing for ceramic fibers in the past few years has been a combination of increasing concern for energy conservation, the trend toward high temperature manufacture and governmental regulation (i. e., OSHA regulation for occupational exposure to asbestos). (13) In some instances, ceramic fibers have replaced asbestos in thermal applications; how ever, ceramics have been used primarily to replace other conventional high temperature material (l.e., firebrick in refractory applications which operate at temperatures greater than the upper limits for asbestos). The cost of ceramic fibers is on the order ten times the cost of asbestos on a pound for pound basis, although on a product utilisation basis, the costs are reported to be reduced to a differential of two to three times. The literature has also identified other materials that conceivably could be used to replace asbestos in some of Its traditional cement ap plications. In the USSR, slag pyroceramics is one of the new building materials produced from metallurgical slag. Applications include industrial floors, decorative and protective facings, dividing walls ll" *"> -Wiyyyf.^r- - /*)( ' CRMC-M&S-002804 I and particians, and root coverings. {14) It is reported to be non-toxic l and more wear-resistant, durable and chemical resistant than ceramic products and does not show water absorption or warping like asbestos cement. The Soviets also report on an experimental fiberboard made from basalt material that ia lightweight, temperature resistant and purportedly superior to asbestos slabs. (IS) In Czechoslovakia, research was reported of a basalt type of mineral wool, "A-Fiber", which has ber-js developed as a substitute in asbestos cement, (16) However, it was.a determined that the material could only be used to replace up to approximately 207* of the asbestos without causing severe degradations in product strength. Finally, research in India has slledged that it is commercially feasible to produce cellulose pulp-cement sheets comparable in strength to asbestos-cement sheets for use in building boards. (1?) Other sources have provided information that wood ia cement sheet material makes the end product more sawable aad aailabla, but it is water sensitive and would fail in outside environ ments. F.eportedly, the product would have a limited interior usage. WollasUnite and mica have also been evaluated as a reinforcing fibera and fillers for cement applications. According to Johns-Manville, compared to asbestos cement, these materials result In reduced strength even at partial substitution. Their singular advantage would be in cost reduction, through materials cost or processing costs. S. 30 CRMC-M&S-002805 5.2.4 Competitive Products and Market Structure The major market for both correlated and flat cement sheets is in the construction industry as external and/or internal coverings for warehouses and industrial buildings, especially where corrosive vapors are present. As stated previously, other major uses include cooling tower fiSi sheets, canal liners, laboratory table tops, and electrical switch gear. Table 5.4 indicates the size of these various sub-markets for a/C sheets, competitive products and estimates of market position. The market for A/C shingles and siding products is highly regionalized and generally limited to l$ew Jersey, Long Island, eastern Pennsylvania, New Orleans and San Antonio. A/C siding is used primarily because it Is fireproof and its appearance attractive. Industry sources differ on the total size of the A/C shingle market which is esti mated to range between 0. 5 and 1.0 million square feet. This market appears to be declining over the past few years asi evidenced by the 1967 Census reporting 1.9 million square feet which declined to 1. 3 million in 1972. This trend is further borne out by Johns - Manville' s decision to stop producing A/C shingles in 1975 and National Gypsum recently closing two asbestos-cement siding plants. The total else of the A/C siding market is less than 1 million squares per year (one square 100 square feet) with the total U.S. tiding market estimated at 60-80 million squares per year. Brick 5.31 rr%r i \ CRMC-M&S-002806 t S ourcei CONSAO Converaatlona w ith jo lu io * to n v iU o C o r;.., .iu lio n a l Ct>puum ami Supradar rf - *520 a 8^ 2 "< x - S 2 - * j? ^ o ua * 5 | 2 g u t "g . |Js S|2<2ig-5ot j 9 _ > * i * "bf _ i!M ,; st *y * s as **3* 5ft*a g* 1= g>5 " >. x- 1 2^ ? 2 s'? e *s . * r r < c* .3 S = 5`*S o.'-2a2--'' 5S-!Iat*a3j3 5 g S S , S = %**!* zl'il S>.a(j:lS9 0,s2< Siu-3ai -fSsf 12s J ~ 2 S - S 1-2 id 3 S u 3 j g 8 -2 H * I 1 > I C -3 * a< > t3 2 |`lls Is jut I 5 2 s *^Js .^.213 2 .2 - g S g s S S *t * J ^ 2 2 2 SiJlJI-"- --C 3b X --R 3 S*" *U 4|593 ~ 30 6o 2% sSa3,,.0b*a"*4r,Orj"__b.jM^-<2 eu a-0 3 3 i3 !c M" "" s| Jf - ^ c "gws Sw.''1S*4'3e3Ji|*; ,, H " J'-J -- .-x- mmat m J? jSgCael g i I o 5_ S_ **if,>2 iTJS. `5^ gi J2-g-ti: 2^5-2 S||a SS"| g . -8 -Soil o||2 0 5 S iut! 5^ .4>-S`c:1i3 .5^_ *3 c**-c w3 Wo ^o"u*o. 0* a ^_r~-r "s uo Pt s5ob -85 a 1 --S ff"'l?52s-s'2 - i| S SoJ^i- at St 2 8 - 2|! - = -=.5 | S > c ou"',is< S = * ; b 2 x3iul 5 5 S - - a .- |1?-S3S a iS S~ i2 5 I < S S x < 2 E 2 J-*2w3 2 39 0 Hi H j a. < = ^ -- j-. S 11 s S. g m ** O 5fJ-* 5 a M i!i 1 I w I|| s! if* H !, -3 . *s* i i 1 1 " i*?22Sjg J?5 O?b *25 u~ ss *|i 51 2 I 1 S | 1 * 3 | 51 Ai M J 1*3 2S i IIIMt* 111 1 a * |l !i | ti issi ie ll 31 X il 'I ?3 1 ij ls 33 *? So 32 r.T,*-T,y,w -"Trr'Tr CRMC-M&S-002807 A has approximately 20% of this market followed by hardboard (Masonite), aluminum, and other forest products. The residential siding market encompasses over half of the total siding market; however, competition from aluminum siding and more recently vinyl siding, has reportedly forced A/C siding from this market. The major applications for A/C aiding Is now limited to those areas when special fire protection is required or slate-like appearance Is desired. A significant factor which may affect the market for A/C sheet products would be aggressive enforcement of the current 2 fiber/cc asbestos exposure limit and forcing contractors to comply with the other ancillary requirements of the standard. littls exposure is associ* ated with the installation of A/C siding or shingles because factory panels are simply nailed up, bolted on, or screwed in. More exposure is associated wih the installation of A/C sheet, which sometimes requires secondary fabrication or cutting at the construction site. This is especially true for flat or corrugated sheets used in roofing and walling for industrial buildings, as opposed to other sub-market* for A/C sheet where almost all cutting and fabrication is done in the shop. A situation could develop where ordinary contractors who only rarely use A/C flat and corrugated sheets, would stop using the product rather than engage in monitoring, medical surveillance, record keeping, etc. However, based on conversations with users of A/C sheets, a select 5.33 'TTTrr-vyp---- rr~.*T,Y ;is ! I group of contractors could begin to specialize in working with A/C sheets and would he willing to work with A/C sheet and comply with the standards. Current enforcement of the 2 fibers/cc standard may slightly reduce the total demand for A/C sheet. The market for A/C flat sheet architectural panels may decline, however, this is a very small part of the total market for A/C sheets. S.M 1 p**f I I CRMC-M&S-002809 S. 3 Friction Materials I 3.1 Background Friction materials comprise a line of products that rely upon r* i . their coefficient of friction with a mating surface to stop or trmtmit motion* - In the case of brakelinings, the most common type of friction material, the function of the lining is to convert the kinetic energy of a moving mass into heat energy. Brake linings are produced in a variety of forms such as segment linings for drum brakes, disc pads for disc brakes and brake blocks. They can be designed to be riveted to a metal backing or bonded with an adhesive. Other types of friction material include industrial linings for manufacturing equipment and appliances such as washing machines and clutch facings of the molded and spiral wound type. Asbestos in conjunction with the phenolic resin binder ar.d other additives (commonly called "organic" friction materials) develop the proper coefficient of friction to provide smooth, safe braking action. Asbestos can withstand the high temperatures generated at the braking interface and contributes to the needed dimensional stability of the lin ing. The fibrous nature and high tensile strength of chrysotile asbestos impart strength to the friction element and allow It to withstand the stresses over a wide temperature range. Asbestos also contributes 3.3$ CRMC-M&S-002810 r to the wear characteristics of the lining so that it docs not score the mating surface yet provides long life. These same characteristics are important in clutch facings. The general formulation of asbestos fric tion materials are: Asbestos -- 50-80% . Binder -- 16-45% Friction Modifiers -- 5% In 1974, approximately 55,000 tons of asbestos went into the domestic consumption of friction materials which represented approxi mately 6% of the total U.S. asbestos consumption. The major submarkets for asbestos friction materials arc identified as the automotive original equipment market, die automotive replacement market, and the industrial market. 5. 3. 2 Technological Fea s ibility Review of Process Bags of asbestos fiber are typically weighed, opened manually, and placed in movable hoppers for in-plant transportation. The hoppers are dumped into mixers, which blend the formulations in either a wet or dry state, depending on product specification. If the type of mixers used are not sufficient to refluff the asbestos, then a fluffing device is also used. The mix is fed through a compression molder (dry) or an extruder (wet), dspendlng on the required product. Formed strips are cut and S. 36 CRMC-M&S-002811 bent into various width* and lengths. A mold release compound is added to prevent parts from sticking. Dry-mixed formulations include a small amount of solvent and are transferred to pressing molds where slabs are formed, sometimes after a preheating step. The slabs are then hot pressed, causing the resin to flow and bins. the mixture upon curing. These slabs are next sawed into specific parts and sent to a curing oven. Following curing, the parts undergo a irunbe r of finishing steps needed to produce the final block. These machining operations include awing, grinding, drilling, blanking, tapping, and boring. Brake pads may be packaged and sold to a secondary manufacturer y bs applied directly to brake shoes by bonding or riveting. The asbestos formulations are wet processed where it is prac tical to meet product specifications. This reduces the potential for a*bested fiber loss in the workplace. Enough solvent is added to form a coherent mass which can be molded or extruded. After drying, the preshaped part is cured. Control Methods and Work Practices Centralised local exhaust systems are employed with flexible connections to evacuate dust from individual machine operations, using hoods and enclosures to advantage. Where raw fiber is handled, the plant layout is generally arranged to segregate, if not isolate, this5 5. 57 ^tWt^nrur "*mr ,*r ti CRMC-M&S-002812 r operation from other production areas. Surface dust on the products at intermediate and final stages is a major cause of worker exposure, and many operations undergo a brushing operation to remove latent dust. Manual inspection of parts should be done on down-draft air- i exhausting tables to minimise exposure. i: Floor cleaning should be conducted nearly continuously, as most plants operate three shifts per day and up to seven days per week at * peak periods. Vacuuming ia the general housekeeping practice; how ever, brooms are al <o used where toe spilled material is difficult to vacuum. L Reported Exposure Levels Continuing correspondence and phone interviews with industry i representatives, together with a review of recently-published exposure { levels (1,2,3) show the time-weighted average (TWA) asbestos ! exposures in friction materials operations to range widely from 0.1 to 1. i > 10 flhers/cc. However, even toe lower reported levels have generally been achieved with less-toan-iull-scale, optimum application of cur rently available, proven control measures and work practices. Currently Achievable Expose?* Available, proven control measures and work practices which could be used now to better advantage to assure low exposure levels Include toe rigorous application of well-known methods, such as: S.S8 i t CRMC-M&S-002813 ,* i  Regular performance checks and preventative maintenance on local exliaust systems; Immediate clean-up of spillage and floor accumula tion of asbestos-containing solids using central vacuum-cleaning systems; floor cleaning at least once per shift with a powervacuum unit -- preferably combined with wet floor cleaning; and . Mechanically-supplied, contaminant-free make-up air (tempered relative to ambient conditions) in sufficient volumetric flowrates to balance the com bined local exhaust capacity in a given work area. These measures, together with the consistent, exacting application of control measures described above would, in the contractor's judgment, achieve exposure levels consistently below 0.5 flbers/cc on a time- weighted average basis for friction materials operations. Future Controls Under Development Advancing technology for reducing exposure levels in the friction materials operations includes automated product-surface cleaning and more machine-integrated local exhaust, especially the low-volume, high-velocity type of application. Projected Lowest Achievable Exposures Table 5. 5 shows the projected lowest-achievable exposures that caa be attained as a result of the exacting application of control methods mentioned previously and die timely Implementation of new technology as it is developed. In summary, the contractor believes that TWA 5.3* * .......... 1 - '*" > .v(V CRMC-M&S-002814 Table 5. 5: Reported nd Projected Asbestos Fiber Concentrations Friction Material Process-Related Hork Areas Fiber Receiving & Storage Fiber Introduction Hiring Forming or Rolling Curing Finishing Adjustment & Printing Inspection Packaging TWA Asbestos Exposure Level (fibers/ce) Reported Leva1s | Currently 1 Achievable Projected Loves t Achievable 0.2 - 2.5 0.3 0.2 0.4 - 4.6 0.4 0.2 0.2 - 8.0 0.5 - 22 0,5 - 3.5 @.5 0.4 0.4 0.2 0.2 0.2 0.6 - 7.4 0.7 - 1.0 0.4 0.4 0.2 0.2 0.1-15 1.0 - 2.0 0.5 0.5 0.2 0.2 5.40 'Hi 1 crmc_M&S- 00281s exposures in the friction materials segment can be maintained con sistently below 0.2 fiber/cc within two years. 5. 3. 3 Potential for Material Substitution There is presently underway an intense research and develop ment effort to find acceptable substitutes for asbestos is "organic" friction materials. Due to the competitiveness of the business, specific compositions and costs are considered proprietary; therefore, only general statements can be made at this *ime about these research and develop programs. Graphite and carbon fibers have been attempted in friction materials and both Goodrich and Goodyear have patents using graphite in aircraft brakes. Additionally, in the USSR; graphite fiber has been introduced into a eerment friction material for a braking gear for air craft. (18) There has also been research in using carbon and graphite in disc brakes; however, problems were reportedly encountered in processing. Furthermore, these materials are extremely expensive and probably would not constitute an economically feasible substitute for asbestos in the major passenger ear brake systems. RaybestosManhattan has been attempting several varieties of fibers and materials as asbestos replacements in brake linings. Some of these include fibrous glass, mineral wool, wollastinite, potassium titan *e fibers, heat resistant organic mineral fibers, and natural organic fibers such 5.4! ~ ;- -tt-tv-^7-- 7T'"'TT--' "r "J " 11 CRMC-M&S-002816 ! t i. I . as cotton and sisal* With the exception of wollastinitc and the natural organics, the other fibers are all more expensive than asbestos. The leas expensive fibers apparently lack the heat resistance and sufficient fiber strength to give good strength to the brake composite material. r Another problem is that many of the fibers (e.g.. glass, graphite, c and mineral wool) tend to break up in the milling process and would require a new coupling agent for use in friction materials. Raybestos f has reported that, in general, new or modified processes would have to be developed for manufacture of these asbestos-free friction materials. Sa its pass, the National Aeronautical and Space Administration L (NASA) has investigated new friction materials and their applications outside of die space program. Under NASA's Technology Utilization Office, Stanford Research Institute developed an improved friction material for light weight cars and trucks which utilized potassium L titasate fibers (Dupont tradename FYBEX) and other polymer modifica tions. Commercialization efforts ceased when Dupont withdrew FYBEX f I from the market due to toxicological effects and other market considera tions. (If) (See Appendix C for information on FYBEX. ) la the area of woven clutch facings, some progress is being made I in utilizing fibrous glass as a substitute for asbestos. Johns - Manrills has a patent for fiberglass clutch facings dated 1973, yet reportedly no license Ms been issued to date. Raybestos * Manhattan is currentlyS. I S. 42 *iY; CRMC-M&S-002817 undergoing pilot plant aludies to evaluate the performance of a fiber glass clutch facing they recently developed; however, no futher Infor mation is available. The Bendix Corporation, one of the largest manufacturers of auto motive friction materials, is also undergoing an intense research and development effort to find a non-asbestos organic brake drum lining. Za conversations with research and development management, they report guarded optimism for a recently developed material. Bendix * admits that the subject is still fluid, yet they seem encouraged by the results. For proprietary reasons, no specific information was obtained. In general, though, it waa reported that the cost differential between this new material and conventional asbestos brakes was esti mated to be in the 10s of percent. Due to the variety of manufacturing processes Bendix uses throughout this country, and the world, some manufacturing processes would have to be changed while other would only have to be slightly modified. Bendix reports that supplies of the raw materialJbr the new brake composition are available, but the exact economics have not yet been worked out. Another point brought out in this conversation is that Bendix has attempted to find a substitute fiber that does not have similar physical characteristics of asbestos (i.e., the fibers would not have the dimensional characteristics that would lodge in the lung). It was further indicated that with a year, Bendix ......... S.4J #. r i . .... M rM- CRMC-M&S-002818 hopes to be able to demonstrate their near composition brake lining as a commercially viable substitute to asbestos in drum brakes. 5.3.4 Other Friction Materials There exist numerous types of friction materials, different in composition as well as configurations. As discussed previously, these materials generally consist of an asbestos-reinforced polymer filled with various property modifiers and are conventionally called "organic" friction materials. For heavy duty applications such as aircraft, and occasionally race cars, and for certain transmission clutch .implica tions, copper or iron matrix materials, reinforced with steel fiber and reinforced with various ceramic and metallic property modifiers are used. Materials of this type are called cerment friction materials. For application intermediate in duty between organics and cerments, there exist another class of friction materials, Le., "semi-metallic" which consist of steel fiber reinforced polymer filled with iron and other property modifiers. (20) The cerment (sometimes called sintered metal) brake linings are used primarily in heavy duty applications where high torque capacities and longer life are required (e.g., aircraft brakes, as noted, earth caoving equipment, army tanks and off-highway vehicles. In many of these applications cerment brakes apparently exceed asbestos brakes fa* overall performance, especially la the aircraft brake market where 5.44 nrrr^TiT--* f .... crmc-m&s 002819 ccrment brakes market share is continuing to grow. Their performance in cold weather is adequate and their noise is comparable with asbestos brakes. However, the price of those brakes range has been estimated to between 3 and 5 times that for asbestos brakes, and probably for that reason, their share of the on-road, truck market is very small, estimated at approximately 5% in conversations with Abex Corporation. The semimetallic, or sometimes called resin-bonded metallic brake linings are presently being used in heavy duty automotive applications (e.g., police cars and taxi disk brakes and also in semi-tractortrailer truck brakes). They are reported to be superior to asbestos brakes in performance; however, there are certain aspects of the brake that detract from their use in the passenger car market. The semimetalies have a tendency to perform erratically in different temperatures, they Cede and are noisier than conventional asbestos brakes. Furthermore, they are currently 50-60% more expensive than conventional asbestos brakes. Abex Corporation, who manufactures res in-bonded metallic brakes has estimated that under increased produc tion, the cost of these brakes could drop to within 25% of present asbestos brakes. General Motors has reported using a hybrid disc brake in the mass production of Camaros, Firebirds, and Chevelles, These are disc brakes which consist of one semimet&Ulc and one organic asbestos lining. 'I........ ,J- 1 5.45 -.'"!rnyy reywmr*''"............ 11 " /< 9 . ,. 1 CRMC-M&S-002820 I The asbestos lining docs not ftcfetlly touch the rotor snr&ce, but octs more to insulate the brake fluid from the heat generated hy the friction surface* In effect, utilising these hybrid brakes reduces the asbestos content of tfca friction material. They were initially developed to meet higher performance standard for newer model cars. Compared to asbestos disc brakes, they have a higher coefficient of friction, higher heat resistance and will wear longer, yet they are mere noisy and more expensive. Precise information on cost were not available for proprietary reasons- Some industry sources feel that these metallic brakes will gradu ally take over the market due to its superior performance characteristics. However, other sources believe there may be a trend away from using metallic brakes because of the future emphasis on lower maxi mum speed limits and lighter weight cars for fuel economy. Both of these factors may indicate less of a need for brake performance. None theless, it is not within the scope or competence of this report to be able to predict the needs of the braking systems of future car markets. most of the major friction material markets, the organic asbestos material predominates. On a cost-performance Lsis, its thermal resistance, mechanical and ability to bind the other materials in the composite has made asbestos friction materials the preferred choice for most of these applications. 3.46 CRMC-M&S-002821 Sales of asbestos friction materials totaled $300 million in 1974, The precise breakdown of sales and production for each submarket ( (c,g., original equipment automotive, replacement, industrial markets) la not presented due to imprecise information and the complexity of the market structure. However, at present, the non-asbestos friction materials, e.g., cerment and semi-metallies, appear to have only an insignificant share of these markets. Therefore, on a competitive product basis for friction materials asbestos has no peer. .47 TT TfS M CRMC-M&S-002822 5.4 Vinyl-Asbestos Floor Tile 5.4.1 Background Vinyl asbestos floor tiles are manufactured from filled polyvinyl chloride polymers or copolymers and produced in squares usually 9inches x 9-inches or 12-inches * 12-inches with thicknesses varying from 1/32 to 3/32-inches. They have found wide use because of their ease of installation and maintenance, durability and rot resistance. They can be embossed with a variety of colors and patterns or mottled with splashes of different colors. Tiles are fastened down with asphalt based adhesives or a self-sticking adhesive which is put on at the menufactoring facility and covered with a release paper. Id the manufacture of floor tile, asbestos gives a cohesiveness or hot strength to the material that allows it to be processed to the final product. Asbestos imparts indentation resistance, dimensional stability and abrasion resistance to the product in use. Various formu lations are: . Asbestos - 5-20% Binder - 15-20% Limestone - 53-73% Plasticiser - 5% Stabiliser - 2% Asbestos consumption in vinyl asbestos (V/A) floor tile segment was approximately 110.000 tons in 1974 which comprised about 13% of the total U.S. domestic fiber consumption. Next to asbestos paper and . .. .......... 5.48 ....... . ' ........." 1 """................................................... . *... ` ., I 4 CRMC-M&S-002823 cement pipe, floor tile ranks third in overall consumption. V/A floor tile compete in the resilient floorins market which also includes asphalt tiles, all vinyl tiles, and sheet flooring. I ' 5.4, 2 Technological Feasibility t ' ` Review of Process Modern floor-tile manufacturing uses shearing mixers into which opened paper hags or unopened polyethylene bags of asbestos are manually dumped, along with other dry ingredients such as plasticizers, resins, stabilizers, and pigments. f The mixer works the batch mix into an agglomerated, homogenized ^' plastic mas at a temperature of about 300F. The hot mix, with the f* asbestos fully bound in the warm plastic, is dumped onto a conveyor and passes to a 2-roll mill. The mass undergoes final mixing and is formed into a continuous r {_ slab during milling. The slab, with an initial thickness of one to two inches, is fed through successive calendar rolls to achieve the desired final-product thickness. The sheet remains warm and pliable as it is conveyed through embossing, which adds design features and texturing to the surface. After partial cooling and waxing, tee sheet is cut into squares by a cutting press, and the Lilas are separated from the excess scrap, f' Inspected, and packaged. The scrap and rejected tile are reworked and returned to the mixer for recovery. *.49 11 - J- 1 ,,u"` ...... ............ ............... 1 ..............-.n,' -7, --vyr-T-------- ---------- 1---------! 4 CRMC-M&S-002824 s Control Methods and Work Practices Floor-tile manufacturers use a High degree of local exhaust as dust control technology along with routine floor cleaning to minimize worker exposure to asbestos. Because the mixing and forming steps do not cause asbestos fiber loss, the fiber introduction step (for opened **I) and background levels represent the prime concern for controlling exposures to low levels. Nevertheless, the materials handling equipment, including mixers, are kept under nga.tiv9 pressure with exhaust air directed to a dustremoval system. Scrap material is conveyed to an isolated or enclosed area where automated choppers process scrap into chips. Worker exposure in scrap recovery is minimal, although this operations is usually exhausted locally. Reported Exposure Levels Several plant visits plus continuing correspondence and phone interviews with industry representatives, together with a review of recently-published exposure levels {1,2,3) show the time-weightod average (TWA) asbestos exposures In floor tile operations to range widely from < 0. I to 4.3 fibers/cc. Sa Clayton's judgment, however, even the lower reported levels have generally been achieved with lessthan-fhil-seale, optimum application of currently-available, proven control measures and work practices, 5.50 - --'---- vf,'--'mi ~ CRMC-M&S-002825 Currently Achievable Exposures Available, proven control measures and work practices which could be used now to better advantage to assure low exposure levels include the rigorous application of well-known methods, such as: Regular performance checks and preventative maintenance on local exhaust systems; Immediate clean-up of spillage and floor accumula tion of asbestos-containing solids using central vacuum-cleaning systems; Floor cleaning at least once per shift with a powervacuum unit -- preferably combined with wet floor cleaning; and Mechanically-supplied, contaminant-free make-up air (tempered relative to ambient conditions) in sufficient volumetric flowrates to balance the combined local exhaust capacity in a given work area. These measures, together with the consistent, exacting application of control measures described above would, in the contractor's judg ment, achieve exposure levels consistently below 0,4 fiber/ce on a time-weighted average basis for floor tile operations. Future Control Under Development No marked technological advances are expected in the floor tile segment for reducing exposures other than timely application of semiautomated bag opening and/or conversion to high-density fiber, together with increasing levels of automation in mixing and forming -with resultant decrement# in worker proximity and exposure. 3.51 t.-tsv1--yr-- ~,-v vr,' * CRMC-M&S-002826 Projected lowest Achievable Exposures Table 5.6 shows the projected lowest-Achievable exposures that Clayton believes can be attained as a result of the exacting application of control methods mentioned previously and the timely implementation of new technology as it is developed, in summary, the contractor believes that TWA exposures in the floor tile segment can be maintained consistently below 0.2 fiber/cc within two years. 5.4.3 Potential for Material Substitution Presently, there is an intense R&D effort in industry to find suit able substitutes for asbestos in floor tile. Armstrong Cork is reported to offer a non-asbestos floor tile using more limestone than conventional V/A tile. In conversations with Johns -Manvilie, compared to the asbestos tile, it is not nearly as flexible and has a tendency to be friable. Switching to this type of tile would require a heavy capital investment to change the manufacturing process and has been estimated at approximately $100,000 per line. Johns -Manvilie has reported work with fibrous glass and ball clay in floor tile. They report that the brittleness of glass caused severe degradations in the normal manu facturing process. It was concluded that ball clay could be used as a partial substitute; however, complete substitution was judged to be questionable from a product property standpoint. S.S2 ________________________ 17 'WTr;*--" A . CRMC-M&S-002827 Table 5.6t Reported and Projected Aabcstoa Fiber Concentration* Floor Til* Freceas-kelated Work Areas Fiber Re calving > Storage Fiber Introduction Blending lenbary Riser EilliftS Calendering Eiabessing Catting Inspection Peeking Scrap A Rework TWA Asbestos Exposure Level (fibers/cc) Reported Levels Curreacly Achievable Projected Love8t Achievable <0.1 - 2.5 <0.1 - 4.3 <0.1 - 4.3 0*8 3 - 0.3 0.4 0.3 0.3 0.3 o.CM 0.2 0.2 0.2 0.2 m - . 0.3 0.3 0.3 0.3 0.3 0.3 0.2 0*2 0.2 0.2 0.2 0.2 3.51 <9 1 '7 %VT.---------- crmc-^&s' : i'i Union Carbide has reported the development of a non-asl>cstos floor tile. By adjusting *:be resin formula to include a new petrochemical material, the reinforcing characteristics of asbestos are presumably not needed. Presently, the performance o the new floor tile is being evaluated, and its price is aledged to be competitive to vinyl asbestos floor tile. St was reported, however, that the availability of the sub stitute petrochemical resin (which is proprietary and not divulged) is not sufficient at this time, if an instant switch to this product were to occur. Union Carbide reports that if a demand were generated for the I material, adequate supplies could be probably made available on a large-scale basis. A great dsal of interest has been generated by the development of a natural cellulose fiber, Monsanto Corp., tradename SANTOWEB, r which Monsanto claims will prove to be an acceptable substitute for asbestos to reinforce floor tile, u purportedly can be used in existing L manufacturing processes and is capable of withstanding 300F during calendering operations. Presently, the cost of SANTOWEB is $. 60/lb f: vs $. 06/lb for asbestos. However, due to its better color clarity and brightness (cream color vs grey asbestos tile), the need for pigments is reduced 75fias compared to asbestos floor tile. Additionally, Monsanto claims that 1 pound of SANTOWEB will replace 5 pounds of asbestos by using other fillers in tho process. Therefore, the end 5. 54 TT rTTri * V' CRMC-M&S-002829 price of the tile itself may be comparable to that of V/A tile* Monsanto Is currently working with five floor tile companies and by the end of this year* it is believed that final plant trials will have been completed. Because the product tea sot been commercially produced at this time, no objective evaluation of its performance characteristics was possible. 5*4.4 Flooring Market Structure Resilient flooring products come in two forms* tile and sheet. Asbestos is mixed with vinyl material to produce a vinyl asbestos tile which is loss expensive than an all-vinyl tile* yet retains superior characteristics of attractiveness, durability, and directional stability. The cost reduction and performance characteristics of vinyl asbestos tile has made this type of tile the dominant choice in the resilient tile market. In 1958 sheet vinyl was introduced into the resilient flooring market in competition with linoleum and by 1974, it has virtually dis placed linoleum* Vinyl sheets are customarily installed with a cushioned underlayment with an estimated 81% of all permanent sheet vinyls being cushioned* Asbestos paper is combined with latex to provide an underhymeht for such installation, but underlayment composed of organic materials is also available* However, asbestos latex is generally the preferred choice duo to Its rot resistance, dimensional stability and cushioned effect. 5.95 4# ** /A CRMC-M&S-002830 Resilient floor cover ini; is subject to product competition from carpeting and hardwood flooring in many applications. Such competition is conditioned not only by price but also by purchaser preferences. Over the past 15 years there have been dramatic shifts in the shares of the flooring market held by carpeting, resilient flooring and hardwood, with carpeting significantly increasing its share. Several factors seem to have accounted for the growth in carpet ing's share of the flooring market. Over the decade of the sixties prices fell relative to other type of flooring. New home builders began to sell homes with installed carpeting, allowing new home purchasers to finance carpet purchases as part of their mortgage financing. New fibers provided more attractive lower priced carpeting. Carpeting made some penetration into the non-residential market. Finally, ris r: ing real estate incomes per capita may have led to some product sub stitution. The basic reason for developing asbestos vinyl tile was to sub stitute a lower cost material for vinyl. Currently, solid vinyl tiles i costs 3 to 10 times as much as asbestos vinyl tile. Clearly, there will L be significant attempts to find substitute fiber rather than go back to a solid vinyl floor tile. The feasibility and cost of such substitute fibers * r are discussed in the previous Section 5.4.3. r ( 7 9.56 T.ir,r"wr ! ' GCr" CRMC-M&S-002831 Vinyl-asbestos floor tile and sheet flooring arc the predominant products in the resilient floor market. la 1975, V/A tile had 38% ot the rcsiliant market while 53% was captured by vinyl sheet. The remainder consisted of asphalts and all-vinyl tile, cushioned and non- cushioned sheet vinyls. For the entire rcsiliant flooring market, 1975 end-use applications are listed as follows, by percentages New Residential Construction -- 18% Residential Replacement -- 42% New Commercial Construction -- 19% Commercial Replacement -- 21% The "dc-it-yoursclf" market continued to play as Important role in the sales of vinyl asbestos and vinyl tile products. (21) The Predicasts Research Group out of Cleveland, Ohio has esti mated that the growth of rcsiliant flooring in new and replacement markets will remain static through 1985 with most of the increase in demand being fulfilled by carpeting. (22) However, CONSAD does not have sufficient information to determine the specific demand for vinyl- asbestos floor tile as it relates to either the rcsiliant, or the total flooring market. 5.5? -nr 7T CRMC-M&S-002832 5. 5 Reinforced Plastics 1.5.1 Backffimnd The largest uses of asbestos in the plastics Industry are for vinyl asbestos floor tile and phenolic molding compounds. It is also used to a touch lesser extent in other plastics as polypropylene, polyester, nylon, melamine, epoxy, eilicone and vinyl. The most important func tion of asbestos in plastics are reinforcement, dimensional stability, heat resistance, flow control and general-purpose filling. As noted in the previous section, vinyl asbestos floor tile comprises one of the major primary Industry segments of the asbestos industry and is covered vadsr its own section, 5.4. While asbestos is used in many plastic applications, the following discussion will focus only on phenolic mold ing compounds which predominate as the major user of asbestos in reinforced plastic applications. The major market for phenolic molding compounds are automotive, household applicances, and electronics. Other markets include wiring devices, communications, and closures. The major competitors phenolic have in these markets are other plastics, such as polypro pylene, nylons, polyester, alfcyds and polycarbonates. However, it also competes with die cast metals, &.e., aluminum in certain light weight automotive applications. The specific breakdown of shares for phenolics and its competitors for these various markets is not presented S.S8 r,T ?r%*f ...... J CRMC-M&S-002833 due to lack of sufficient information. Nonetheless, demand for phenolics presently is growing. In 1976, industry sources estimated that produc tion of phinelic molding compounds was approximately 350 million lbs. while the production for the past 5-6 years has ranged between +15% of 300 million pounds. (23) The average selling price for phenolics has been estimated to be approximately $. 50/lb; therefore, the total sales of phenolic molding compounds in 1976 was approximately $175 million dollars. Tho portion of total phenolics that were reinforced with asbestos for heat and strength properties is not precisely known. Yet industry sources have estimated die asbestos reinforced contribution at approximately 25%. or about 85 million lbs with total sales in the neighborhood of $40-45 million dollars. (24) There is presently a well-defined trend to replace asbestos in L . phenolic molding compounds, documented both by the literature and in L numerous conversations with manufacturers of reinforced phenolics. This movement was initiated in 1972 when General Electric started replacing asbestos in their phenolic products with a new talc-based filler which they called E-Grade. (25) Recently, the Durez Plastics C Divisioo of Hooker Chemical Company, who reportedly have 40% of the total reinforced phenolic market, haa developed a non-asbestos rein forced product. They report that by July, 1977, their entire line of phenolic molding products (e. g. automotive, appliances, wiring, com munication, electronics and electrical switch gear) will be reinforced 5.59 CRMC-M&S-002834 with this now, non asbestos material, A crude approximation of the progress of this replacement effort was elicited from various industry sources. A rough consensus developed in that after July 1977 between 50 to 70% of phenolic applications which formally used asbestos as a reinforcement will have switched to non-asbestos substitutes. For this reason, CONSAD judged that the reinforced plastics segment of the primary asbestos industries in most cases, would opt to substitute for asbestos as opposed to expending further capital sums for engineering controls to attain these lower exposure limits. However, there apparently are some specialty products where no feasible asbestos substitute has been found. The Rogers Corporation has reported that the phenolic molding material used in commutators and rotors in the electrical and automotive applications currently are reinforced with asbestos. These products function in a very dynamic environment where temperatures of 350F and 30,000 RPM are preveient. Asbestos provides the heat resistance, dimensional stability and moldability necessary for these applications and in their experience, no substitute for asbestos fiber exists for their applications. Nevertheless, the overall trend to replace asbestos in phenolics is evident. More than likely the conversion process will be slow, and in some cases costly as new processing techniques are implemented. It may very well be that asbestos will remain a reinforcement material in specialty applica tions If exposures can be controlled to within acceptable limits. 5.00 --------` 1 ------------ f.wr'?.yp"......TT'-"1 ' ' --1 "" ' `1 ' crmc-m&s-0025 However, in view of the general substitution trend tho technologies! feasibility of controlling asbestos exposures to 0. 1 fiber/cc was not undertaken* The following discussion focuses on these substitution efforts in more detail* 5*5.2 Substitutes for Asbestos The material most often identified as replacements for asbestos in phenolic molding compounds are talc, clay, and fibrous glass depend ing upon the desired end-product properties. Talc ' General Electric's asbestos-free Genal phenolics utilize talc as the major reinforcement materials in conjunction with aluminum, silicates and cellulose fibers. (26) GE claims that this new material has the same basic properties -- including impact strength, dimensional stability and heat resistance -- as their previous asbestos filled pro ducts. {27j IBs predominate use is for heat resistant phenolic molding compounds in the medium temperature applications with its limit deter mined at 45F. GE does report that some minor product strength is sacrificed by using this new material, and that more breakage can be anticipated aa compared to asbestos filled phenolies; however, GE suggests that manufacturers can compensate by building thickcr-walled products. There is no significant difference in die price between asbestos-filled and the Genal product and GE reports that the same processing equipment can accommodate th? new material. 5.61 sm i* a CRMC-M&S-002836 's ; Although the composition o the non-asbestos phenolic compounds developed by Hooker-Durex is proprietary, it is believed to be of a day base. It too is reported to maintain an acceptable balance between heat resistance and impact strength that the asbestos-filled phenolics provided. The price of the substitute material is indicated to be com parable to asbestos used in these applications (i. e., $. 10/lb). Addi tionally, supplies are reported to be readily available. Hooker-Dures maintains that die laboratory development of the substitute took approxi mately 2$ years, while customer acceptance was achieved in a year period. Furthermore, no change in die production process is mandated by using die new material. Fibrous Class . Fibrous glass is the principal reinforcing material in plastics mad is an integral part of most new engineering plastics, la higher temperature reinforced phenolics, glass has been suggested as a possi i ble replacement for asbestos. Class fibers are on the order 5 times more expensive than asbestos ($. 50/lb vs $. 10/lb) and glass filled i: - phenolics are. reportedly harder to manufacture due to the brittleness of the glass than asbestos filled. The Rogers Corporation reports that glass libers will la many applications provide the bulk and strength oeeded, but because of their briuleness, are unsuitable for molding S. 62 % "17n? CRMC-M&S-002837 ** applications wi:ich their customers use. Another prime consideration in molding of any product is the resin's ability to flow in the mold cavity. In very simple molds, glass fibers arc acceptable; however, in complex molds or fine detail requirements, they tend to segregate from the resin binder and fracture. Finally, the abrasiveness of glass apparently affects the "tool wear", or durability of processing equipment. It has been reported that to use glass instead of asbestos in certain reinforced phenolics would necessitate a change in processing equipment. The extent to which glass is replacing asbestos in certain phenolics molding com pounds is not known at this time. Other Possible Substitutes Jim Walter Resources Inc. has recently developed a processed mineral fiber made from blast hirnace slag and silicates. It is reported to be able to reinforce a variety of plastic materials including phenolics, nylons, poly'dutalene. epoxye, and polyolifins. Its safety category, as covered by pertinent OSHA regulations, is that of an "inert mineral due" On a comparative price basis, the material is approximately twice as expensive as asbestos fiber ($. 15/lb vs $ 06/lb). The material is too now to determine what penetration it is having in rein forcement plastic market; however, Jim Walter reports a growing list of customers in this market, (28,29) 5.63 .... 1,1,1 '.*,< Tf'f " t, ,*, ' ------ - " - '* \ CRMC-M&S-002838 1 : Although much too expensive to be considered an economic replacement for asbestos, graphite fibers arc presently being utilized mjs a reinforcement in molded phenolic*; polyamides, expexies and polyi. astus.(30) Like asbestos, they can be used to provide phenolics with r-- resistance to acids, alkalis and solvents suitable up to 150C.{31) In 1971 potassium titanate fibers introduced by Dupont, trade*. name FYBEX, were reported to be a suitable replacement for asbestos r* | . in many applications, but were primarily considered to be used as a plastic reinforcement. However, in 1974 IXipont withdrew FYBEX from the market due to unfavorable health hazard potential and slow I. market growth. (See Appendix C for a further discussion of FYBEX.) r; i. i! E E E S.t4 t "wp--iTgr*1 'tmfp , # '\ CRMC-M&S-002839 S. & Paper Products 5. 6. i Background The asbestos industry classifies asbestos paper products into several product groups. These product classes are differentiated pri marily by the raw material content of the product and its end-use. In general, die asbectos fibers impact to these products rot resistance, dimensional stability, and resistance to flame, heat and corrosion. Tabic 5.7 presents the breakdown of the U.S. paper market, ita esti mated production by product class. For the entire segment, approxi mately 330.000 tons of asbestos fibers were consumed in 1974. which represents 38% of total U.S. fiber consumption. Therefore, asbestos paper product# rank as due leader in overall U.S. domestic consump tion of asbestos. The following subsections present background infor mation far each of these product categories. Many of these product descriptions were taken from a study sponsored by the Government of Quebec on the characterisation of the U.S. asbestos paper markets.(32) Flooring Felts Asbestos-latex paper for sheet-goods flooring Is a felted sheet composed principally of asbestos with moderate amounts of a Latex binder. Important properties are surface and caliper uniformity, tensile strength, and resistance to water absorption. S.f.5 rwr" v. CRAir. t Table 3*7: U.S. Asbestos Paper Market Estimated Production by Product Class, 1975 Product Class 1 " Flooring Felts 1I Roofing Felts Lr~ Gasket Pipers Pip line Wrap Production Tons 125,000 120,000 30,000 26,000 Percent Share 39 37 9 8 Commercial Paper and Millboard 11,000 3 Specialty Saturating Paper 5,000 2 Corrugated Paper 3,500 1 Muffler Paper ij . Specialty Paper 3,000 Minor I 323,500 i .. Sources Artfeur D, little of Canada, Ltd, f* [ t* L i iihii iiiT.ii*fi1>.iiliTi>l-. *.66 u' ` ' CRMC-M&S-002841 i ! i f I. I T i r i ! i* The paper it converted to a finished flooring product in a variety of operations wluch may include rotogravure printing or embossing of a pattern to the polyvtoy chloride coating that serves as the wearing sur face of the sheet. The finished sheet is available to many patterns and it eaty to install above or below grade. Aabeetoa. toe major constituent of this paper, is used to provide rot resistance, dimensional stability, and resilience in combination with the latex. A general formulation would be: 9 85% Asbestos 15% Latex The latex to most cases would be a styrene-butadiene type. Roofing Felts Roofing paper is a felted sheet material usually manufactured to weight of 9i to 15 lbs/100 sq. ft. The material is composed principally of asbestos with varying amounts of cellulose fiber and starch binder. Other materials, such as wet and dry str ength polymers, fiber glass, mineral wool, and inorganic fillers are often used. The basic sheet is saturated and/or coated with asphalt and used in the construction of built-up roofs. The asbestos in the felt resists wicking of moisture into the roof ing system, resists decomposition of the roof system with age, and seelsts toe felt to remaining dimensionally stable under changing atmospheric conditions. 5.67 . - $ ... ...... .......1 mm..... py'v'vf"1'1 1 /^r CRMC-M&S-002842 ^MBBMtoWSMessseesMw^^-^.------------_______ _ 4 Wide variations exist in the formulations for roofing felt, A general formulation would be: , 85-87% Asbestos . 8*12% Cellulose . 3-5% Starch Binder As mentioned inorganic fibers and fillers and assorted polymere may be added in small amounts to modify various properties of the sheet. Casket Paper Gasketing paper or "beater add" paper should be distinguished from milled or compressed asbestos gaskets, which are not a paper product. Asbestos gasket papers are composed of 60-80% asbestos and 20-40% polymer. The product. In roll form, is die-cut to form gaskets. These gaskets are sold primarily to the automotive industry and have a variety of applications, such as head gaskets and carburetor gaskets. Asbestos paper gaskets are often used in combination with metal gaskets; in this application they serve as a cushioning material. However, much of the discussion on gaskets is contained in Section 5.8 under the packings and gaskets segment of the primary asbestos r industry. Pipe Line Wrap r t Pine line wrap is a rolled asbestos paper product, reinforced with parallel glass strands, and saturated with asphalt or coal tar. i 5.68 CRMa 'f 02843 j \ 1` \ *i-- i i. The product is used as a wrapping for underground and submarine pipe lines for corrosion protection. Commercial Asbestos Paper and Millboard Products Commercial asbestos paper and millboard products - encompass a broad range of papers which vary primarily in wefght and thickness. The product is composed of 95-98% asbestos fiber and 2-5% atarch filler. For millboard, the filler can also be cement or other inorganics. The products are sold in rolls (rollboard). sheets, and tapes. The principal end-use of all these products is to provide Insulation of mini mum thickness against fire, heat and corrosion. Papers are used in electrical insulation, ovens, gas ranges, safes, welding mats and other similar applications. Millboard has an important use as a conveyor material in glass and steel factories. Specialty Saturating Papers Specialty saturating papers - are a paper product that is saturated with a thermosetting resin. The paper is wrapped or rolled and then cured to form a hard, heat-resistant substance. It Is used principally in high-pressure decorative laminates and in cooling towers. Corrugated Paper Corrugated paper is a commercial paper product that is corru gated and cemented to a flat paper backing. It is sometimes laminated with aluminum foil. Because of its lightness and flexibility, the pro duct is used to insulate curved surfaces. 5.69 CRMC-M&S-002844 Muffler paper is a waffled or indented asbestos paper product which is used in exhaust emission control systems in automobiles. The product is used primarily a# a wrap between the inner and outer skins of a muffler. Another, less common use is as a heat shield between a muffler and the body of the automobile. Specialty paper products are made to order for numerous specific applications. Some of these products are flame barrier papers (used in aircraft and ships), filter papers (used in pharmaceuticals, beer and wine), electrolytic diaphragms, and high tempsmature trans former papers. 5.6.2 Technological Feasibility Review of Process Production of asbestos paper products begins with introduction of dry asbestos fiber into the process. Individual bags are opened (manually or semi-automatically), and the contents dumped either to a holding hopper and conveyed to the stock preparation area, or directly into the stock-preparation vessel without intermediate storage. "Pulpabl" Kraft paper bags containing raw asbestos fibers can be added unopened to the hydropulper or beater without the manual bag-opening and bag-disposal steps. h the stock preparation step, asbestos, paper stock, binder, and other additives are wet mixed to specified concentrations and 5. TO TTTT^ it Ml CRMC-M*S-002845 consistencies using hydropulpcrs or beaters. The stock is then pumped into a holding vat and subsequently to the papermaking machine. Asbestos-paper machines for commercial paper and roofing felt include the multi'-cylinder and Fourdrinier types which closely resembles machines used in non-asbestos papermaking. Rotating cylinder molds form the wet plys which are then lami nated and press-rolled to remove excess water. Wet paper is routed through a dryer on steam-heated drums to attain desired moisture content. After drying, it passes continuously to a cutting/slitting area to be cut into rolls. The paper product can be packaged directly or rewound. After rewinding on spools, the final product is packaged and wrapped for bull: shipment. Control Methods and Work Practices Stock preparation includes fiber introduction -- dumping or whole bag addition > to a beater or hydropulper. Such equipment is kept under negative pressure by its inclusion in an exhaust system connected with a larger dust-collection system*. When asbestos -containing pulpable bags (Kraft paper) are introduced directly into the stock prepara tion. tills eliminates exposure from bag-opening and bag-disposal. Housekeeping in the stock preparation area represents a crucial : control component for minimising operator exposure to asbestos. Use of central vacuum-cleaning systems and mechanical floor sweepervacuum units should be routine in these operations. 5.71 CRMC-M&S-002846 The stock slurry flows into the papormaking machine and forms a "sheet" with solids content less than five percent. Although the moisture content is reduced greatly during transit through the paper machine, die wet nature of the material largely precludes the release of airborne asbestos. Nevertheless, rigorous housekeeping and clean up measures are critical here as well. Worker exposure in this area can be minimized by preventing spilled material from drying and thus creating a potential dust source. The steam-heated rolls in the drying section are typically canopyhooded and exhausted to remove water vapor and heat. This type of hooding and exhaust augments the general ventilation in the area and aids in removing asbestos particulate released during the drying opera tion. Local exhausts, area hoods, and exhausts connected to a central collection system represent the normal control measures used to mini mize asbestos exposure at the slitting and calendering stages. House keeping is also critical here. The rewinding step Involves bulk packaging of paper products on spools, reels, or beams from larger rolls. The operation is com pletely dry, and area hoods and exhausts typify dust-control measures at these operations. Housekeeping operations in use for this procc** step are Identical to those for stock pr9p*r*tion and papermaking steps. 5.7* (. 9 CRMC-M&S-002847 Currently Achieve do Hx*our<p Available, proven control measures and work practices which could be used now to better advantage to assure low exposure levels include the rigorous application of well-known methods, such as: $ Regular performance checks and preventable maintenance on local exhaust systems; Immediate clean-up of spillage and floor accumula tion of asbestos-containing solids using central vacuum-cleaning systems; Floor cleaning at least once per shift with a powervacuum unit -- preferably combined with wet floor cleaning; and Mechanically-supplied, contaminant-free make-up air (tempered relative to ambient conditions) in sufficient volumetric flowrates to balance the com bined local exhaust capacity in a given work area. % These measures, together with the consistent, exacting application of control measures described above would, in Clayton's judgment, achieve exposure levels consistently below 0.4 fiber/cc on a time-weighted average basis for papermaking operations. Future Controls Under Development Advancing technology useful for reducing asbestos exposures in asbestos papermaking operations includes more high-automated equip ment for greater enclosure and better ventilation. The effect of binder and flocculating agents on fiber release is also as on-going research and development program as It may affect toe optimum papermaking stock composition and end-use functionality. 5.73 ; % CRMC-M&S-002848 ! Projected Lowest Achievable Exposures Table 5.8 shows the projected lowest-achievable exposures that can be attained as a result of die exacting application of control methods mentioned previously and the timely implementation of new technology as it is developed, fa summary, the contractor believes that TWA exposures in the papermaking segment can be maintained consistently below 0.2 fiber/cc within two years. 5.6.3 Substitute Materials and Competitive Products Asbe* os Imparts to paper characteristics of dimensional stability, durability, resistance to alkali attack, and thermal insulation. As dis cussed previously, die asbestos market is divided into several major categories. Where information is available, substitution possibilities and competitive products are discussed below for each of the product categories. Flooring Felts Flooring felts are used as a base for vinyl sheet flooring or as a underlayment for vinyl tile and carpeting. These materials have com peted very successfully wife organic, or jute felts in fee past. How ever, development of foam cushion backings, and backless flooring will place competitive pressures on asbestos flooring felts, fa Europe, fiberglass mats are being used as an underlayment to resilient sheet flooring; however, the dimensional stability is not as good as with 5.74 w^fj? '-ffr1?"? 1 -------------------- -- /* Cj^C-M&S-002849 0A P+ 1 tW o M ____ 1 Table 5.8: Reported and Projected Asbestos Fiber Concentrations Asbestos Paper and Felts Process-Related Work Areas TtfA Asbestos Exposure Level (fibcrs/cc) Reported Levels Currently Achievable Projected Loves t Aehievnb! *. Fiber Receiving & Storage 0.2 - 2.5 0.3 Fiber Introduction 0.3 - 2.8 0.4 0.2 Stock Preparation 0.1 - 2.7 0.3 0.2 Pape making <0.1 - 1.0 0.3 0.2 Drying 0.5 - 1.5 0.3 0.2 Slit and Calendering <0.1 - 1.6 0.3 0.2 Rewinding 0.3 0.2 Splicing <0.1 - 0.4 0.3 0.2 !. t9 I CRMC-M&S-002850 BP asbestos flooring fell. Domestic research activities have also tried { Dupont's "Nome*" aramid fibers, fiberglass, cellulose fibers; yet no acceptable substitute for asbestos has yet been determined. ? Roofing Felts ^ ?i la She first half of the current decade, the asbestos roofing felt market was one of the fastest growing of the asbestos products markets. After a 1968 American Society for Testing and Materials recommenda tion, asbestos felt roofing began to make rapid penetration in organic roofing felts' share of the built up roofing market. Its technical advantages over organic systems lie in its rot resistance, dimensional stability and in the fact that it does not require a gravel surface. This last feature makes die roof easier to inspect and repair. In 1976 built ap roofing sales of all types were about 53 million squares. Organic systems had about 45% of the market, asbestos felt 25%, and fiber glass felt 10-15%. Just as asbestos felt made rapid inroads into die organic market share, industry sources believe that fiber glass roofing will reduce both die share of organic and asbestos roofing felts in die built up roofing markets. Fiber glass has the same technical features as asbestos for a roofing product, but it requires f less asphalt saturation* Both fiberglass and asbestos systems are inorganic. Inorganic systems have better rot resistance and dimen sional stability than organic systems. * * -w r 5.76 .............. M ~ CRMC-M&S-002851 With tnc escalation of petroleum and n is Lottos fiber prices* fiber glass systems have become less expensive than asbestos felt systems. While prices vary widely across the country, the current average price for a "ravel surfaced fiber glass system is $30/squarc (including labor and materials). This compares with $39-$40/square for an organic system and $46-$47/square for an asbestos system. Continued expansion of fiber glass capacity can be expected to maintain downward pressure on asbestos roofing felt prices, thus preventing asbestos roofing felt manufacturers from passing on cost increases. According to Arthur D. Little of Canada estimates (32), the free market price of asbestos roofing felt was very close to manufactur ing cost in 1975. If their estimate is correct, asbestos felt may be entirely priced out of the market by fiber glass. Casket Paper There is presently very little competitive products or adequate substances for this product category. See also Section 5. 8. 3, Packings and Caskets. Pipe Line Wrap The coal tar enamel asbestos felt system for oil and gas pipelines is still the most competitive and preferred of all systems. But since 1973 the price of this system has doubled with increased prices for asbestos fiber and increased cost of production for asbestos paper. 5.77 *TT >/ i \ CRMC-M&S-002852 This has enabled saturated fi;x-ri:Las3 outer wrap to <;air a j;rt:atcr share of the market, and become the chief competitor for asbestos felt as a component of the same general system. Alternative systems include epoxy coatings, PVC tape, and PE tope. Continually increasing prices for asbestos pipe line wrap will certainly decrease its share of market In this competitive field. Commercial Asbestos Paper and Millboard Products Domestic research for substitutes have centered on fiber glass, cellulose, ''Nome*'1 and "Kevlar" fibers.* Johns-Manville reported on research with glass fiber which resulted in a weak, brittle, more expensive product that required a new forming system for manufacture. Other industry sources have quoted a glass paper developed for thermal applications costing approximately $2/lb as compared to $. 35/lb for asbestos commercial paper. Cellulose papers lack the temperature L` resistance of asbestos paper and they do not have equivalent dimensional stability under relatively high humidity and temperature. For electrical Insulation applicatisns, XXipont has marketed a "Komex" paper which is thorntally stable. Dame resistant, moisture resistant and has excellent electrical properties. (33) D has been approved by Under- See Section 5.9. 3 for more discussion on Nomsx and Kevlar libera. L S.7 I -"W.rfTSr1 CRMC-M&S-002853 writer# Laboratory for tempera lure# up to 220C# liie cost o' Nome* papers varies from $0-$7. ?5/lb depending upon its thickness and density. The extent to which Nomex paper has competed with asbestos commercial papers has not been determined. Ceramic mineral fibers. "Kaowool" by Babcock and Wilcock, Inc. and Carborundum's "Fiberfsx" have seen applications recently in millboard and rollboard in which the asbestos has been replaced. These materials have very good temperature resistance up to 2300F. but do not have f.m reinforcing capabilities of asbestos. Ceramic papers are also 9 great deal more expensive than their asbestos counterparts with price* ranging from $5*$l0/lb as compared to $e 35/lb for com mercial asbestos papers. Due to this price differential, ceramic papers cannot be considered as an economically direct replacement for asbes tos in all paper applications. Muffler paper has been one of the fastest growing products in the asbestos paper Industry due to their use in catalytic converters in emission control systems. Nevertheless, industry sources have revealed that the automobile industry is currently looking for a replace- a meat for asbestos in these applications, presumably to glass, or ceramic papers. Other Applications fa the specialty paper market which includes asbestos filters and diaphrams, some progress has been reported in replacing aslicstos. 5.79 CRMC-M&S-002854  The Durez Division of Hooke? Chemical Company has developed a new membrane made from perflurosulfionic acid resins for use in chlorinecaustic production. They claim that this new material, tradename NAFION, represents an improvement over asbestos diaphrams and is loss expensive. However, they do report that the membrane is not as efficient electrically as asbestos diaphrams. (34) Saffil alumina fibers by 1CX in England show promise as high temperature and chemical resistant filtration medium. They have demonstrated to be an effective replacement for asbestos filters in breweries. (35, 36) % .e rsTrrmrF* rnr i CRMC-M&S-002855 '?V f t s ' 5.7 Gaskets, Seals and Packings 5.7.1 Background Asbestos is the most widely used material for gaskets and packing because of its resilience, strength, chemical inertness, and heat resistance. These asbestos materials are used in nearly every industry, household, machine, and transportation vehicle. A wide variety of products are manufactured using raw asbestos fiber, textiles, and.asbestos paper. The asbestos may be bonded under heat and pressure with materials such as nitrii rubber or chloroprene for resistance to oil and solvents. In fact, a wide range of materials Is used in compounds with asbestos to engineer a product of highly specialized properties. Although some dry asbestos packing is used to seal furnace doors, rotary Mas and high-temperature refractory equip ment, packing generally incorporates a lubricant and is typically made by braiding asbestos yarns which are Impregnated with a grease-base lubricant. As a distinct Industry segment, packings and gaskets consumes approximately SO, 000 tons of fiber per year based on 1974 estimates. However, this figure may be misleading by itself because of these 50,000 tons is included 21,000 tons of fibers used in beater-add gaskats, a paper product. Therefore, not counting beater-add gaskets, 29,000 tons of fibers went into this segment and represent about 3% of the total If.S. asbestos consumption. S.8! "" ~..-- 1 "iimy|YM"a ` * $ *9 '*\'r CRMC-M&S-002856 4 i r 1. f. i; r c i: L i: p This segment of the primary asbestos industry is further compli cated by the fact that the materials used as packing are in actuality asbestos textiles. Therefore, the gasket, seals and packing segments described in this section also includes materials from the paper and textile segments. For example, manufacturers of sheet and beater-add gaskets sell pressed gasket material to gasket manufacturers (numbering around 40 establishments nationwide). These firms may then sell to gasket cutters, numbering between 200 to 300 establishments, or they may go directly to end-users. For consistency in the discussion on substitutes and competitive products, there exist six major product lines of packing and gaskets which contain asbestos. There are: Compression Packings Molded Packings Sheet Caskets Beater-Add Caskets Spiral-Wound Caskets . Metal-Clad Asbestos Caskets S.7.2 Technological Feasibility Review of Process Caskets. Asbestos bags are opened manually and dumped into a mixing tank or a conveyor leading to the mixer. In some cases, the compressed raw asbestos is dumped into a fluffer for fiber opening before the mix step. Fillers and bonding materials are also added to the mixer, and the mixture is blended. Mixing may be in a dry or wet state, accord ing to the product requirements: multiple production lines may be employed. S.R2 rr;v * CRMC-M&S-002857 < * The formulation from the mixer is calender-rolled into sheeting. The sheeting may be packaged and sold to secondary manufacturers for further processing, such as gasket cutters. The sheeting could also be sold in sheet form to distributors serving the maintenance market. Packings. Asbestos-based packing can be manufactured by a number of processes. The most common method is to impregnate dry yarn with lubricants, which coat the fibers. These yarns are then braided into a continuous length of packing, and then calendered to specific sizes and cross-sectional shapes. The sized braid may then be coiled, boxed, and sold to the maintenance trade, or it may be cut and die-formed to manufacturer's specifications. A variation of braided packing can be produced by first extruding a mixture of asbestos fiber, binder, and lubricants, and then braiding lubricated asbestos yarns over the extrusion. Control Methods snd Work Practices The greatest fiber exposure potential for the gaskets and packings segment is associated with the manual handling, opening, dumping, and mixing of raw asbestos from bags as wall as bag disposal. These exposures srs controlled by local exhaust ventilation snd floor cleaning. Where mixing is accomplished with a wetted compound, fiber evolution Is lew. Fiber exposure during braiding and twisting of treated asbestos yarn can likely be controlled adequately by local exhaust supplemented S.ftS rxnrxrsr . CRMC-M&S-002858 /iff :'r i: by general control measures, including dilution, ventilation, and system atic cleaning. Reported Exposure Levels r Several plant visits plus continuing correspondence and phone interviews with industry representatives, together with a review of recently-published exposure levels, show the time-weighted average r %TWA) asbestos exposures in the gaskets and packings segment to range widely from 0. 1 to 2.5 fibers/cc. However, even the lower reported levels have generally been achieved with less-than-full-scale, optimum application of currently-avaliable, proven control measures and work practices. n Currently-Achievable Exposures Available, proven control measures and work practices which could be used now to better advantage to assure low exposure levels l include the rigorous application of well-known methods, such as: i: 1. Regular performance checks and preventative maintenance c on local exhaust systems; 2. Immediate clean-up of spillage and floor accumulation of c asbestos-containing solids using central vacuum-cleaning systems; i' S. Floor cleaning at least once per shift with a power-vacuum Lf * unit - preferably combined with wet floor cleaning; and r r S.M CRMC-M&S-002859 M' 4. Mccha nically-suppHcd, contaminant-free make-up air (tem pered relative to ambient conditions) in sufficient volumetric flowrates to balance the combined local exhaust capacity in a given work area. These measures* together with the consistent, exacting application of control measures described above would, in Clayton'e judgement, achieve exposure levels consistently below 0.4 fiber/cc on a timeweighted average basis for the packings and gaskets segment. Future Controls Under Development New control techniques for the gasket and packings segment relate almost exclusively to fiber receipt and dumping, including Improved packaging of raw asbestos and the ultimate conversion to semi-automated dumping end use of more densified raw fiber. Projected Lowest-Achievable Exposures Table 5.9 shows the projected lowest-achievable exposures that we believe can be attained as a result of the exacting application of control methods mentioned previously and the timely implementation of new technology as it is developed. In summary, the contractor believes that TWA exposures In the gasket and packings ssgment can be main tained consistently below 0.2 fiber/ce within two years. * - .* * 5.R5 syj.rw... . ww ti i ' CRMC-M&S-002860 TABLE 5.9 REPORTED and projected ascestos fiscs, concentrations GASKETS AKD PACKINGS Iroetis-KaUttd Work Areas TWA Asbestos Exposure Level (fibers/cc) Reported Currently Achievable Projected Lowest Achievable Fiber Receiving & Storage Fiber Introduction 0.2 - 2.5 0.5 - 2.5 0.3 0.4 0.2 0.2 Hiring <0.1 - 1.0 0.3 0.2 Braiding end Twisting (damp process) Sheet Formation Cutting/Packsging 0.1 - 1.6 0.2 - 0.3 0.1 - 0.5 0.4 0.3 0.3 0.2 0.2 0.2 S.B6 wrw,rfw,7 " Tvs**. i ; CRMC-M&S-002861 S. 7. 3 Substitutes and Competitive Products Table 5.10 presents the various sub-markets fur asbestos packings and gaskets. It also includes size and share of these markets in addition to major competitive products for each major line. Compression Packings Compression packings are also known as mechanical and braided packings. These materials are actually asbestos textiles that ha vs bssn braided for flexibility snd resilience. The asbestos also acts as a reinforcement for longer wear, heat and chemical resistance and has the ability to hold a lubricant, then discharge Ut under pressure. Cotton, jute and flax packings work well In cold environments (below 0 C) and cotton is acceptable at room temperature for water pump applications (38V However, these materials will not function at elevated temperatures. TFE*. Dupont trade name TEFLON, yard can be used In applications up to 500 F and has the chemical resistance of asbestos in the extreme ph ranges, 1-2 ph for strong acids, and IS-H for very caustic material, la a conversations with SEPCO Company, it was found that TFE filament yarn la 8 times more expensive than woven asbestos ($10 to $12 lb. vs. $l.S0-$l/75/lb. for asbestos) and would increase the selling price f the tetraflu roethyleae 1.87 ..... *... . * vi CRMC-M&S-002862 anp.este ** *$ I i CRMC-M&S-002863 Source: Connersationa w ith Industry Representatives packing 4 to 5 time over the asbestos packings. Furthermore, TFE packings will not hold lubricants like the asbestos packings, thus decreasing their overall acceptance. Graphite filament yarn is presently being used in packing applica tions where extremely high heat and chemical resistance are required. It Is able to withstand temperature up to 1500 F; however, because of its poor tanflle strength it is difficult to process. Compared to asbestos packings, graphite packings are extremely expensive ($30-$?5/lb.), and yet Its popularity is growing due to its increased resistance to heat and chemicals which add significant product life over conventional asbestos packings. A third high-priced substitute for asbestos packing is ceramic yarn which costa approximately id times that of asbestos. It has good chemical and temperature resistance, but is also has poor tensile strength and is extremely abrasive. As is evident, there do @xjt substitutes for asbestos mechanical packings, but no one material will be adequate for all the different applications which asbestos enjoys. With no economic considerations, asbestos could be replaced with some performance penalty. However, the raw material cost would be an order of magnitude greater than asbestos.5 5. i CRMC-M&S-002864 <* - 9 MoMcd Packing Molded packings use asbestos and rubber in a compression pckfa| to be used as a seal around rotating shafts. There are presently substitutes available especially in low temperature applications organic such as cotton or Jute could be utilised. Canvas molded packings are also in use today and as less expensive than similar types of asbestos packings. In higher temperature applications, glass textiles could be utilised. The cost of these glass packings would be slightly higher than comparable aabestos packings. Additionally. Grafoii. a graphite molded packing manufactured by Union Carbide can withstand tempsra* tares of 3000 F and could replace asbestos is many high temperature applications. However, it is mush more expensive. Sheet Gasket? The asbeetos sheet gaskets impart dimensional stability, reinforce ment. heat and chemical resistance, aod resilience to stress and relaxation. Approximately 75 to 80% of the sheet gasket applications are to seal flanges at temperatures below 500 F. The organics, cotton and jute, do not have the temperature resistance for these applications. Fibrous glass is brittle and subject to chemical attach. Dupont's Teflon mixed with fillers is being used for sheet gaskets at temperatures up ta 500 F; however, it Is significantly more expensive than asbestos ($3.50-$4.00/lb. with glass fiber filler vs. $l/lb. asbestos). Other 5.50 CRMC-M&S-002865 m pcrformanc penalties are that tiie teflon will squeeze out of the gasket under extremely heavy mechanical loads, l. e. , 2000 psl. Additionally, under a heavy load the gasket will deform over time. Dupont sources indi cate that Teflon filler mixed with carbon or graphite improves the perfor mance characteristics greatly, but also adds significantly to the cost. Beater-Add Caskets Beater-add gaskets are actually a paper product made from the same machine as used for latex sheet underlayment for vinyl sheet flooring. Property characteristics have already been discussed in Section 5.6 for the paper segment of the asbestos industry. At present, no suitable substitutes liave been found for the asbestos beater-add gaskets. Furthermore, in applications that are not both critically sensitive to high heat and pressures, these gaskets are taking over a greater share of the gasket market. Spiral-TVound Caskets These metal gaskets utilize asbestos paper and are found pri marily in high temperatures. Asbestos spiral wound gaskets have approximately 90% of the market. Teflon may be used when greater chemi cal resistance is needed, and Crafoil, a graphite material, is utilized where very high temperatures are present. 5.91 rv "V'jit;' CRMC-M&S-002866 I Metal Clad Asbestos Gns?-:ct8 i Those gaskets use asbestos as a filler in a metal sandwich and r * i find use In heat exchangers in Industry. Apparently, no competitive products exist for this asbestos application. IV Common Problems Associated r with Non-Asbestos Gaskets As has been shown, there do exist many varieties of substitutes . and competitive products that could replace asbestos. However, there ti is not one single substance that is compatible with all of the asbestos gasket applications. From a practical standpoint, if industry were i' forced to switch to non-asbestos gaskets, many different types of gaskets would have to be stocked and problems may result from improper selection. Additionally, for varylag temperature and chemical applica tions, asbestos gaskets have proven to be an excellent performer, not r only on a technical basis, but also on cost. Other materials are invari ably more expensive, and in many instances, the re may be a performance penalty in switching to a non-asbestos gasket. t 5.M i CRMC-M&S-002867 T ' VI '. *3 - tr. tee** tarn * 5.8Paint. Coatings and Sealants S.8.1 Background Tho primary constituent of this industry segment is asphalt coatings which represent a line of products which have a variety of end uses in the industrial, automotive, and construction Industries. They are produced for such varied uses as protective coat- ; iags for metals and tanks, insulation for pipes and tanks, sound deadeners, sealants and undercoatings for automobiles and roof coatings, flashing cements and tils cements in construction. One type is made from sa asphalt cut back with kerosene or mineral spirits used ss a solvent and the other with an asphalt emulsion in water. The primary purpose of asbestos in coatings is to enhance the rheology of the system and especially the thixotropic characteristics. Since many of the uses involve outdoor exposure the excellent weather ing resistance imparted to the coating by asbestos is essential and its fibrous nature provides the desired viscosity characteristics. The low cost of asbestos in relation to die value added is essential in these low cost products. Because of the variety of products and the number of producers there are unlimited formulations. Tho major components are: S.*J -w "Ff,v...., w CRMC-M&S-002868 'tv ft Cutback Products Cutback Asphalt Asbestos Limestone and Slate Fluor Dispersal 30*80% 10*15% 15-30% 1% Emulsion Products Emulsion Asphalt Asbestos Limestone Dispersant 55*80% 10*15% 5-15% 1% Asphalt coatings and sealants consume approximately 65, 000 tons of asbestos annually, representing around 7% of the total U. S. fiber consumption. For tills report, joint cement compounds is included under this general coatings and sealants heading. In 1974, 13, 000 tons ef asbestos vers used in joints cements: however, this figure is reported to be drastically reduced tor 1976 consumption due to substitution efforts In anticipation of the ban on dry-wall fi 'kling compounds by the U.S. Consumer Products Safety Commission. The major products applications that will be discussed in the subsequent section of substitutes and competitive products include: Asphalt roof coatings 35,000 tons of asbestos Automobile underbody coatings 8,000 tons of asbestos Adhesives and sealants Insufficient data on con sumption f. 94 iu,mm 9 ii * * CRMC-M&S-0028 yd 5.8.2 Technological Feasibility Review of Process The paints, coatings, and sealants manufacturing operations are characterised by two key operations: mixing ar.d packaging. Fiber introduction in this segment represents the critical phase with regard to worker exposure. Fiber fluffing must be used to convert the com pressed fibers to an open, free condition to assure dispersion and encapsulation during asphalt mixing. Fluffed asbestos fiber is transferred to hoppers or directly to a batch mixing tank. Either horizontal, helical type mixers or paddleblade type misers are used to provide homogeneous dispersion. Fiber transfer takes place pneumatically, by mechanical conveyor, or manually. Pneumatic transfer systems are enclosed and exhausted through Abric filters. Conveyors are generally enclosed. Manual transfer may be employed for small batch operations or for specialized,. low-volume requirements. The fluffed fiber and other dry materials are mixed with asphalt (and solvents as required) in a batch tank; in some cases, mixing order is reversed and voly dry materials are mixed Initially. The hatch is mixed sufficiently to achieve uniform dispersion. The batch is mixed sufficiently to achieve uniform dispersion. The batch mixing tanks are normally exhausted to prevent fiber dispersion. After a short mixing 5.95 CRMC-M&S-002870 W y,r * i Cfe IMB * i. _______ time, the asbestos liber is bound in the asphalt. Upon completion of mixing, the asbestos is encapsulated in the asphalt with little chance lor fiber dust exposure. When the batch is finished, the material is pumped to the packaging operation. The predominant packaging for coatings is 5-gallon cans with sealed lids. Special orders are filled occassionally with drum contain ers, and bulk shipments occur rarely. I Control Methods and Work Practices T&e need to achieve a high degree of fiber opening for the paints, coatings, and sealants applications has led to the use of a high-speed Suffer which can create a backdraft that ^odi to offset the control velocity achieved within the fiber dumping hood at the fiber introduction station. This ie offset in part by the fact that the typical fiber introductioa operation is very intermittent, lasting only a small fraction of the work day. Nevertheless, this operation needs to be redesigned or modified to achieve and maintain inlet velocities of at least 250 feet per minute even when the Suffer is activated. No control equipment is installed or believed required from the mixing through packaging stages of processing In this segment. Reported Exposure Levels Recent plant visits plus continuing correspondence and phone interviews with industry representatives, together with a review of | j r S. 96 7~r****r? mTr 9 *? /*\ CRMC-M&S-002871 recently-published exposure levels (1, 2, 3), show the time-weighted average (TWA) asbestos exposures in paints, coatings, and sealants to range widely from 0.1 to 8. 0 fibers/cc. However, even the lower reported levels have generally been achieved with less-than-full-scale, optimum application of eurrently-availablc, proven control measures and work practices. Currentty-Achievable Exposures Available, proven control measures and work practices which could be used now to better advantage to assure low exposure levels include the rigorous application of well-known methods, such as: 1. Regular performance checks and preventative maintenance oa local exhaust systems: 2. Immediate clean-up of spillage and floor accumulation of asbestos-containing solids using central vacuum-cleaning systems; 3. Floor cleaning at least once per shift with a power-vacuum unit - perferably combined with wet floor cleaning; and 4. Mechanically-supplied, contaminant-free make-up air (tem pered relative to ambient conditions) in sufficient volumetric flowratee to balance the combined local exhauet capacity in a given work area. S.f? CRMC-M&S-002872 These measures, together with the consistent, exacting application of control measures described above would, in Clayton's judgement, achieve exposure levels consistently below 0.4 fiber/cc on a time-weighted average basis for paints, coatings, and sealants. Future Controls Under Development Ongoing technological improvements for control of asbestos exposures in this segment of the primary industries relate primarily to fiber receipt, storage, and bag-opening developments discussed earlier in the report. Particular attention needs to be given, and is being given, to the develolment of adequate exhaust hooding for manual fiber dumping because of the importance in these operations to open and fluff the compressed fiber prior to mixing. This high-speed fluffing can create back-draft windage, and this needs to be overcome by adequatelydesigned local exhaust in order to control exposures in the fiber-intro duction phase of the operations. Projected Lowest-Achievable Exposures Table 5.11 shows the projected lowest-achievable exposurea that can be attained as a result of die exacting application of control methods mentioned previously and the timely Implementation of new technology at it is developed. In summary, the contractor believes that TWA exposures in the paints, costings, and sealants segment can be main tained consistently below 0.2 fiber/cc within two years. 5.*S CRMC-M&S-002873 I TABLE S. 11 REPORTED AMD PROJECTED ASBESTOS FtZZZ CONCENTRATIONS PAINTS, COATINGS, AND SEALANTS TffA Asbestos Exposure Level (flbers/cc) r rrocci9"MiiC9a None a?9bb Reported Levels Currently Achievable Projected Loves t Achlevab'e Hbt; laesi^iat & Storag 0*2 2.5 0.3 0.2 r i. Fiber Introduction l.S - 8.0 0.4 0.2 i: Mixing/Compoundiag/Peckaging <0.1 0.2 0.1 i. \: i L. r L r * i- S.99 *# CRMC-M&S-002874 mapm * !* /.t * # V, I r-/ S 8. 3 Substitutes and Competitive Products Asbestos is mixed with aephalt and other fillers to give sealants and coatings dimensional stability. The advantage of using asbestos in asphalt is in the electrical and capillary affinity between the two materials that strengthens the bond between the filler and base. Roof Coatings For roof coating applications, asbestos contributes to the viscosity * Of the fluid, increase the tensile strength through reinforcement, and provides stability in can storage. The amount of asbestos in this material ranges between 15-20%. TREMCO, Inc., one of the largest producers of roof coatings has tried polyethylcnes. poiyproylcnes, polyesters, and acrylics as a substitute for asbestos. They have developed a proprietary substitute with acceptable characteristics in this application, but its cost is 8 times that of asbestos. Furthermore, it is reported that a change in the manufacturing process would be required If these materials were produced commercially. Some success has been achieved utilizing fiberglass as an asbestos substitute in roof coatings. The glass provides reinforcement, but does not contribute to the viscosity of the coating. It also lacks the chemical affinity for asphalt that asbestos fibers apparently have. Fibrous glass used in these applications are on the order 7 times more expensive than asbestos ($ 50/lb. vs $.06-$. 10/lb. for asbestos) and apparently would require a change in the manufacturing process. 5.100 CRMC-M&S-002875 The market for roof contings is divided into fib rated and noufibrated coatings representing 60% and 40% of the total market respec tively. To date* die fibrated coatings are almost completely asbestos filled; however* as reported above* substitute materials may become a factor in the future. The non-fibraded roof coating are generally used for maintenance and repair work. Furthermore, they cannot be used on steep* or vertical surfaces because they will slide off. Asbes tos roof coatings offer the advantages of better weather resistance and a better fire rating. Automotive Underbody Coatings In automotive underbody coatings, the asbestos-asphalt material provides a sound deadener and corrosion resistance. Johns-Manville reports that other materials have not been found to be as effective on a cost/performance basis as asbestos in this application. There do exist others that achieve the same effect of resisting corrosion (i. e. * ainc-procossing to rust-proof automobiles}, but they do not significantly deaden sound. Adhesives and Sealants Asbestos used In adhesives and sealants provide reinforcement, weather resistance and temperature resistance. This market is pri marily in automobile* mobile home and industrial applications. Many scalanta for household use do not contain asbestos* but without asbestos 5. 101 CRMC-M&S-002876 as a fiber. they arc more expensive, A fumed silica (high purity silica oxide) material manufactured by the Cabot Corporation, trade name Cab-o-Sil, la reported to bo an asbestos substitute In decorative coal ings and wood ashesives. Its cost is $1.20 to $3/lb. compared to $. 15/lb, tor asbestos; nonetheless, because of the high selling price of many sealants, Cab-o-Sil can be used aa an asbestos replacement. Percipitated silicas are also reported being used as a substitute for asbestos la sealants. Joist compounds used as dry-wall spackling compounds may not 'be considered sealants or coatings In a traditional sense; however, for consistency they will be discussed under this heading. Over the past few months, there has been a consistent trend to substitute for the asbestos ia this product due primarily to the dust problems encountered la uslag the produet. In April 1977. the Consumer Product Safety Com mission decided to propose a ban on toe use of asbestos in these products. * Therefore, asbestos will continue to be replaced in this application. An asbestos-free dry-wall joint compount was developed by National Gypsum aad utilises attapulgite clay as aa asbestos substitute. It is reported that these asbestos-free compounds have good plasticity, water retention, cohesiveness and viscosity stability (37). The construction industry has estimated that to substitute toe asbestos in dry-wall joint compounds would increase toe price of the compound approximately 12 to I J?. No specific proposal has been published to date. S. 102 CRMC-M&S-002877 5*9 Asbestos Textiles 5.9*1 Background Asbestos libers, ekn worked into textile form, provide a material which is incombustible and retains its physical properties at high temperatures. Asbestos textiles are manufactured in several different forms: Xap - used as insulation for electrical conducters; Roving - used as insulation for heater cards, twisted to form yarn; Tara - woven into textiles; Cord - used for seals, packing, insulation; Cloth - used for curtains, blankets, safety clothing; Tubing - used for sleeving for electrical conducters; Wink - used as packing and sealings; Tape - used for electrical insulation. Typical formulation for those textile products are 75-1007* ehrysotile asbestos and 0-25% organic fibers. The U. S. asbestos textile market consumed approximately 12,000 teas of asbestos ia 1974 which accounted for approximately 1% of total U.S. fiber consumption. The primary end usee for aebeetoe textiles are la friction materials, packings and sealings, protective clothing and thermal and electrical Insulation. 5.103 CRMC-M&S-002878 jShTrfffr , wj. , i 5.9.2 Technological Feasibility Review of Process Asbestos textile manufacturing operations comprise two basic process variations: conventional and wet. The conventional operation can be subdivided into "dry-woven" and "damp" processes. The dry and damp processes differ only with respect to moisture applied to the yarn by contact with water on a roller or a mist spray. The dry-woven * process yields highly specialized yarn without any water contact. Dust release in dry processing is much greater than la damp processing. The newly-developed wet process produces yarn by extruding a chemically-dispersed slurry into a chemical coagulant. The wet-process yarn so formed is dense and tends to hold asbestos fibers better than yarn produced by the conventional process. This has a beneficial l. effect, re stilting In smaller amounts of fibers released to the work environment. Major disadvantages with yarn produced by the wet process include reduced absorption and impregnation characteristics. Textile plants typically produce several products, and thousands of operations occur simultaneously as hundreds of strands are wound, rewound, spun, twisted, braided, and woven. Because of the replicated operations and the continuous, high-speed movement of final and Intermediate yarn products, hundreds of point sources of asbestos fiber !I are present la any given area. n----------11 " ' 5.104 CRMC-M&S-002879 " 1 - ---------------------------------------------------------------------------------------------- m *1 Conventional Process The raw asbestos grades and other ingredients are weighed and dumped iaio several blending machines. The blending machines are operated continuously to gently mix the components of the formulation. The mixing takes place as the asbestos slowly moves toward the rear of the machine, is drawn up an incline, and tumbles back to the bottom. Part of the mix is carried over the Incline and falls into a hopper. The t rear of the blending machine Is enclosed and hooded to minimize fiber valutioa. As the hoppers are filled with the blended fibers, they are transferred to the carding machines. The carding operation combs the fiber mix into a paralleled (oriented) fiber mat. This mat is pressed mechanically and layered into a lap. At the finishing card, die lap is separated into thin contin uous strips of fiber known as "roving". At this point, cotton or rsyon or other materials may be added to the roving to impart strength and other characteristics. The lap, matting, or roving may be packaged and sold to secondary Industries* Otherwise, the roving precedes to the spinning operations. The roving is spun by twisting to die specified number of turns per inch to give it strength. In the damp process, the roving is moistened via wet rollers before spinning. This dampening process is employed to reduce fibrous dust during subsequent processing. In some cases, for reasons of product quality, the roving is not wetted. 5. 105 CRMC-M&S-002880 i. During spinning and further processing, many of the strands will break, releasing fibrous dust as ends whip around the spindles. During this high-speed processing, strands break repeatedly and are repaired manually. 41I - Spun roving, known as "single yarn", can be twisted with other tingle yarn, or other material to produce "plied yarns". Plied yarns can be coated to produce thread or treated yarns, or be woven to pro- duce tapes, cloth, or woven tubing. It can also be braided to produce cord, rope, or braided tubing. Spun yarn can be processed without i: twisting to produce woven, braided, and otherwise-treatad products. At the weaving operations, ths yarn is first put on a beam or creel, which handles a large number of strands to feed a loom". A "damp" or "dry" loom can be used to create cloths of different character i. istics. Wet Process The wet process differs from the conventional processes in that the raw asbestos is dumped directly into a slurrying tank with water and chemicals. The resulting slurry is extruded directly into strands. r These strands proceed to the spinning and subsequent operations similar L. to conventional processing. Ths wet process thus produces the blending \ and carding operations which, la ths conventional process, generates r*- ! substantial amounts of asbestos dust. Wet-processed textiles possess i- 9.106 ? % CRMC-M&S-002881 r~rv ^uiU different chsractcristics than the conventionally-woven products; and therefore, secondary manufacturers most adapt production techniques to compensate for the altered processability and final -product character istics. Control Methods and Work Practices Hoods and local exhau sc are generally employed where raw fiber Is dumped from the bags. The blending machines are normally enclosed partially and evacuated to minimise worker exposure to asbestos. Blended asbestos fiber Is often transported manually to the carding machine, and plastic sheet Is used to cover hoppers during this transfer. To eliminate dust in asbestos textile operations, many of the processes such as carding need to be completely enclosed, coupled, and exhausted with well-designed ventilation systems. When asbestos textiles are processed in a damp or wet state, or otherwise are treated, little, if any, dust is generated during handling. In dry processing, fiber introduction, blending, transporting, and carding are high exposure areas because of the manual handling of raw Hber. Spinning, twisting, weaving, and braiding are expansive operations and, although highly mechanised, require constant worker attendance to repair broken straodo and to make equipment adjustments. The S. 10? CRMC-M&S-002882 -.A. *. .. - -VS..- continuous high speed working of the yarn (spindling, spinning, twisting, and weaving) constantly emits asbestos fiber into the air. Since thou* sands of strands undergo replicated processing in large work areas, isolation of point sources is not feasible. In general, enclosures, hoods, and exhaust ventilation are applied for raw-asbestos-handling operations such as bag opening, blending, wet mixing, and conveying of bulk fiber. Fixed and portable vacuum systems help to control spillage and can be used to keep floors and other surface areas relatively clean. Repetitive wetting of strands is used to control fiber levels. Although spindles have been designed to stop rotating when a strand breaks, this impedes spinning and twisting speeds and retards production rates. Reported Exposure Levels Several plant visits, plus continuing correspondence and phone interviews with industry representatives, together with a review of recently-published exposure Levels (1,2,3) show the time-weighted average (TWA) asbestos exposures in asbestos textiles to range widely from 0.1 to 10 flbers/cc. However, even the lower reported levels have generally been achieved with less-than-full-scale, optimum appli cation of curreatiy-avaUable, proven control measures and work practices. 3.100 CRMC-U&S-002883 Cnrrcntlv-Achicvablc Pxpr>ureg Available, proven control measures and work practices which could be used now to better advantage to assure low exposure levels include the rigorous application of well-known methods, such as: 1. Regular performance checks and preventative maintenance on local exhaust systems; Z. Immediate clean-up of spillage and floor accumulation of asbestos-containing solids using central vacuum-cleaning systems: 3. Floor cleaning at least once per shift with a power-vacuum unit - preferably combined with wet floor cleaning; and 4. Mechanically-supplied, contaminant-free make-up air (tem pered relative to ambient conditions) in sufficient volumetric flowrates to balance the combined local exhausc capacity in in given work area. These measures, together with the consistent, exacting application of control measures described above would, in Clayton's judgement, achieve exposure levels consistently below 1.5 flber/cc on a timeweighted average basis for asbestos textiles. Future Controls Under Development Damp processing and conversion to the newly-developed wet process represents the only real technological advance for controlling S. 109 CRMC-M&S-002884 * worker exposures to TWA levels consistently below 1.0 flbcr/cc. This will require developmental time. Furthermore, all current markets cannot be served with the wet-processed yarn. Projected Lowgafe-AcHievahIc Exposures Tables 5.12 and S. 13 show the projected lowest-achievable exposures that we believe can be attained in conventional and wet pro cessing, respectively, as a result of the exacting application of control methods mentioned previously and the timely implementation of new technology as it is developed. In summary, Clayton believe* that TWA exposures in the conventionally-processed textile operations can be maintained consistently below 1.0 fiber/cc within two years. Similarly, the contractor believes that after the same period, TWA exposures in the wet-proeessed textile operations can be maintained consistently below 9.2 fiber/ce. 3.110 CRMC-M&S-002885 c A\C ifai! SSss&m^iM TABLE 5. 12 REPORTED A (CD PROJECTED ASBESTOS FIBER CONCESTRATIOHS ASBESTOS TEXTILES -- CONVENTIONAL PROCESSING i > *i i I I r 5.111 rr CRMC-M&S-002886 *' * * f IttN _ TABLE 5.13 REPORTED AND PROJECTED ASBESTOS FIBER CONCENTRATIONS ASBESTOS TEXTILES -- WET PROCESSING 5.112 CRMC-M&S-002887 4 5.9.3 Competitive Products Asbestos libers, spun and woven into textile forms, are incom bustible and resistant to heat, corrosion and biological attack. At service temperature above 400 F, asbestos products are presently the undisputed leader on a cost/performance basis. At temperatures below 400 F and occasionally at higher service temperatures where short exposure times are expected, the re are a t somber of fibrous materials which compete for asbestos textile markets. 2a most eases these competitive materials are more expensive than asbestos but are usually stronger (in yarn form), lighter and have a more textile-like feel and appearance. Each of these competitive products are discussed individually be low. Much of this information has been taken Cro n a 1976 Arthur D. Little of Canada study conducted for the Quebec government. Ministry of Industry and Commerce. (39) In reviewing this list of competitive produets, it should be kept in mind that, with the exception of glass fibers, none of these materials were commercially available fifteen years ago. Class Advances in the technology of glass fiber manufacture have been rapid particularly in the last ten years. Class fibers have about the same density as asbestos but glass yarns are stronger and cheaper than asbestos yarns of similar eise. (glass fibers cost approximately 5.113 CRMC-M&S-002888 rnmma * S. 75/lb vs $1.00/lb for asbestos spinning grade fiber.) Class competes directly with asbestos fibers in thermal and electrical insulation ap plications where ultra-high temperature resistance is not required. In addition, glass fiber competes with asbestos fiber in applications where an inert substrate is required for plastic coatings. The total market for glass fiber in the United States is approximately ten times that of the asbestos fiber market and glass fiber applications, particu larly in industrial areas, are expected to continue to grow at least as fast as the growth in real GNP and will continue to compete for asbestos fiber markets. Quarts The market for quarts fibers in the United States is extremely small and restricted almost entirely tb military applications. Quarts fibers are manufactured as a continuous filament material and are used in areas where high strength, high thermal stability, and low electrical conductivity are required. Because of the very high cost of quarts fibers, they do act represent a serious threat to asbestos tsxtile markets. "Norncs** * The term is a registered trademark of the Do Pont Company for aa aromatic polyamide which is manufactured by condensing meta-pheayleaediamiae with isophthaloyl chloride. The product is manu factured as a ctaple fiber, a continuous filament, and as short fibers 5.114 crMC-M&S-002*89 .................. (fibric!*) for use in paper application*. About 25 million pound* of all "Nome*" product* are currently sold in the U.S. market principally for electrical insulation applications and for protective clothing ap plications such as flight suits* where high temperature resistance for short periods of time is required. Other applications includes dryer felts, laundry press fabrics and high temperature filters. The price for "Nomesc"> ranges from $5. to $5. 50/lb for raw fiber and 56. 50 to $10/Ib for continuous filaments as compared to $l/ib for asbestos fiber. "Nome*" is and will continue to be a serious competitor for asbestos test lies. "Durette" This is a product which is manufactured by chlorinating woven fabrics of "Nome*". "Durette" was originally developed by Monsanto, but the rights to the process have been recently sold to a third party. This product has substantially better bent stability than "Nome*" but because of its high cost has found only limited usage in protective clothing applications. "Durette" fabrics are not perceived as a serious competitive threat to asbestos textiles. "Kevlar" The term "Kevlar" is also a registrsd trademark of the Du Pont Company. "Kevlar" is an aromatic polyamide mads by reacting paraphenylenediamine with phtahaloyl chloride. At the present time, "Kevlar" S. 115 CRMC-M&S-002890 .* i rrirrt r^ 45 . i7&.- ..... M -n-.mM. Is manufactured only in continuous filament form and its current principal sic and potential for the future is in tire cord. "Kevlar" has outstanding thermal stability for an organic material having reasonable physical pro perties up to 500 F. It is stronger and has a higher modulus of elasticity than steel, and has excellent flexural properties. The Du Pont Company presently has approximately 6 million pounds of "Kevlar" manufacturing capacity and% has announced plans to expand this by an additional 50 million pounds before 1980. Within the past two years significant quantities of "Kevlar", up to 2 million pounds, have found their way into applications where it Is used as a substrate for plastic coating. The high strength and stiffness coupled with good thermal resistance and good electrical in sulation properties should allow this product to compete with increasing success in the high temperature fiber field. In the longer term, "Kevlar" fibers and fabrics will represent a more serious threat to asbestos tex tiles than "Nomcx." "Teflon" "Teflon" is a registered trademark of the Du Pont Company. "Tef lon" is a perfluorinated polyethylene manufactured by polymerising tstrafluoroethylene la a proprietary process. "Teflon" fibers are manufactured by dispersing "Teflon" particles in a viscous (rayon) dope and extruding tt "Teflon" particles In a matrix of rayon. The rayon is then burned off leaving a contiguous "Teflon" filament. "Teflon" filament products are 5.114 CRMC-M&S-002891  .... . used in application* where high temperature resistance is required such as in the filtration of hot gases. "Teflon" fabrics are also used in areas such as bearing joints where their high temperature resistance and un usually low surface frictional properties are required. About 5 million pounds of 'Teflon" fiber is currently being used in the United States. Less than 10% of this competes directly with asbestos. Tha term "Kyool" is a registered trademark of the Carborundum Corporation. "Kynol" is a phenol formaldehyde polymer which is formed ia the staple fibers is the novelac stage and subsequently crose-linked. "Kynol" fibers have remarkable high temperature stability and find ap plications where lightweight thermal barriers are required. The princi pal limitation of "Kynol" is the fact that while it is inert at elevated tem perature, it suffers from extreme losses of strength thus limiting its use to fairly heavy textile structures where little or no stress is applied. The total market for "Kynol" in the United States is currently less than t million pounds. While it represents a direct threat to asbestos, be cause of the high cost of producing "Kynol" fibers the total impact will be small. On s comparative Cost basis, "Kynol" fibers are priced at $3.60/lb verees $i/ib for asbestos. 1,117 TTwr.-*--!TTr* ' CRMC'M&S~002892 1 Carbon Carbon fibers are manufactured by sintering either fibers of rayon or polyacrylonitrile. The resulting fibers are extremely strong, have a high flexural modulus, are light in weight and have superb re tention of properties at elevated temperatures. Most of the applications for carbon fibers which utilise their high thermal stability are in the military area; however, because of the unusual combination of properties of carbon fibers, a great deal of research has been devoted toward manu facturing technology which would lower the cost of the material. Carbon libers are now being produced experimentally by direct spinning processes which have the potential of reducing carbon fiber prices to the range of $1-2 per pound. Should these developments become commercial, carbon fibers would be a serious competitor for asbestos fibers in many applications Including gasketing material, thermal insulation, and possibly in some friction applications. Ceramic Fibers A new process has been developed by the 3M Company to manufacture continuous ceramic filaments into tapes, cloths and ropes. Thsss materials are characterised by high tensile strength, flexibility and heat resistance up to 2600 F. Potential applications include conveyor belts, furnace curtains, cable and hose coverings for furnace applications. Electrical applications are wire and cable fire protection, heating element insulation 9.118 CRMC-M&S-002893 and braided leering rope for heater Insulation. These materials are very expensive compared to asbestos and arc currently priced from $30-$32.50/lb. Atwttcr ceramic textile cur rent*y in the high temperature market is "Refrasll" developed by the H1TCO Company. It is a pure regenerated glass capable at withstanding temperature of 2200 C and used primarily ae welder' curtain drop cloths, furnace curtain, refractory door and ' . hose coverings* Its price is approximately S9/ib. for the fibers, $28/ lb. spun Into strands. Both the J,3M Brand" and ''Refrasil" ceramic textiles are capable of replacing asbestos on a performance basis. However, their cost would tend to minimize complete replacement of asbestos in high temperature. Furthermore, coma of their furnace applications approaching 2000 C are beyond the useful temperature limit for asbestos; therefor*, these new ceramics should not be consi dered as a feasible replacement for asbestos textile except in very specialized refractory applications. la addition to the list of competitive products discussed above, asbestos fibers are confronted with increasing competition from poly ester end nylon monofilaments in the drrer felt area. The decline in the use of asbestos fibers la dryer felts is directly attributed to competition from these materials which provide higher strength and abrasion resis tance. better filtration properties, and, despite lower thermal resis tance from both polyester and nylon, longer life. $.119 9 r 'TT7mrt CRMC-M&S-002894 As technology for the production of synthetic fibrous materials with high temperature properties advances, competition from asbes tos fiber markets can be expected to increase. 5*9*4 Effect of Imports on Domestic Asbestos Asbestos Textiles Domestic producers of asbestos textile products have faced increasing competition from competitive products and from imports over the past several years. On a poundage basis, imports have more than doubled since 1970 while domestic shipments have declined from 35* & million lbs in 1972 to 31 million lbs in 1976. Imports have made their most significant gains with respect to the markets for yarn and cloth* A significant percentage of the yarn which is woven into textiles for friction material Is now being imported according to a major manu facturer of friction materials. Associated with this phenomenon are re cent production and investment decisions by domestic producers. Garlock has shut down its domestic yarn facility and imports yarn from Canada. Johns-Mansvilla has also curtailed domestic yam production. Significant increases in imports have come recently from Mexico, where Amatex has a minority Interest in Hiladosy Tegidos de Asbestos S, A., and from Venesuela* where Raybestos Manhattan has a 47% interest in Manufactures Multiples* 5.120 M*'*.'1" CRMC-M&S-002895 MWM Imports have penetrated the American market by selling at a discount relative to domestic products. As in the production of organic fiber textiles, labor represents a significant cost component, and labor cost differentials have undoubtedly contributed to the penetration of imports, la addition, the required investment for exposure control mandated by the 1972 emergency standards and the 1976 2 fiber/cc ex posure limit standard appear to have increased the spread between domestic and foreign prices. The maintenance of such a cost differen tial will undoubtedly increase imports share of the asbestos textile market. The continued penetration of imports and product substitutions ha lines where asbestos textiles were once dominant presents a pattern of stagnation and possibly absolute decline for the asbestos textile industry. 5.121 i * i' CRMC-M&S-002896 ? A REFERENCES CHAPTER 5.0 1. Technological Feasibility ar^ Inflationary Tmrjict of Standards for the Control of Asbestos Dust in the Workplace, CONSAD Research Corporation report to the Occupational Safety and Health Administration, July 9, 1976. 2. Technological Feasibility and Economic Impact of OSHA Proposed Revision to the AshestQ3 Standard, Weston Environmental Consultants report for Asbestos Information Association, March 29, 1976. 3. Comments of Johns-Manvillc Corporation with respect to Notice of Proposed Rulemaking Occupational Exposure to Asbestos to the Occu pational Safety and Health Administration, April 1976. 4. Laakard, David R., "Fiber Reinforced Cement-Based Composites", AM Ceram Soc Bull. v54, n3. Mar 1975, p. 272-276. 5. Anonymous, "Micro-reinforcement of Cement", A C Underground, 4, April 1976. p. f. 6. Jones, Herbert L. "Structural Behavior of Polymer-Based C-Class Fiber Reinforced Concrete When Exposed to High-Temperature, Incendiary Conditions:, Society of Plastics Engineers, Annu Tech Co.if., 32nd, v2Q, San Francisco, California, May 13-16, 1974, p. 436-439. 7. Conversation with Owens-Coming Corporation, May 6, 1977. i. Steinberg, Meyer and Morris Beller, 'Class-Polimer Composites for Sewer Pipe Consturction", Miner Waste Util Svmp. 4th, Proc., Chicago, Illinois, May 7-8, 1974, p. 162-173. 9. Arthur P. Little, Xnc., Class Polymer Composite Sewer Pipe An Initial Evaluation of its Commercial Potential, Bookharam National Laboratory, Upton, New Fork, 1972. 10. Development of a Glass Polymer Composite Sewer Pipe from Waefc? Class-Progress Report No. 2, October-December 1976", Broekhaua National Laboratory, Upton, New York, BNL50626, March, 1977.11 11. Japan Economic Journal. October S, 1976, p. 13. 5.122 CRMC-M&S-002897  12. Finnish Tim-g. November 24, 1976, p. 12. 13. Daily News. October 28, 1976, p. 19. 14. Stebakova, Iya. "Economic Efficiency of Application of Slag Pyroceramie Products in Construction''. Class Ceramics, v25 In 9-10 September-Octobcr 1963, p. 620-622. (Russian) 15. European Chemical ?ev.8. April 26, 1974, p. 32. 16. Mach, L., ''Mineral Asbestos Substitute", Paper No. ID/\VG 44/11 presented at United Nations Isdustial Development Organization, October 17. 1969. t 17. Sinha, U.N., ct.al., "Possibilities of Replacing Asbestos in Asbestos Cement Sheets by Cellulose Pulp, " Indian Coner J. v49, n8, August 1975, p. 228-232, 237. 18. Arabei, B. 6., et.al., Cermet Friction Material. Foreign Technology Div. Wright-Paticrson AFB. Ohio, FTD-ID(RS)I-23l6-75, August 10, 1975. 19. Rubber World, July, 1974. p. 33-34. - 20. Rhee. Seing K., ^Ceramics in Automotive Brake Materials, " Am Ceram Soc Bull, v55, n6, Jun 1976, p. 285-288. 21. Resilient Flooring Production Estimates, unpublished data from the Marketing Department. Flooring Mazr.r.ir.e. 22. "U.S. New and Replacement Flooring by Market Type", Predi T-38, Predicast Research Croup, Cleveland, Ohio, July 17, 1975, p. 3. 23. Conversation with Plastics Engineering Co., April 26, 1977. 24. Conversations with General Electric Corporation, April 29 and May 2, 1977. 25. Anonymous, "Phenolics Get the Lead Out, and Some Asbestos Too, " Mod Plast. v49, al2, December 1972, p. 48-50. 26. "Asbestos - free beat resistant thermostable phenolaldchydo molding 1 composite". General Electric Patent B922241, November 25, 1975. 5.123 i ft CRMC-M&S-002898 27. Society Plastic* Fn-ircor* Jrwrnr.l. December, 1972, p. 49- 28. Rubber Age. March 1976, p. 12. 29. R c P News. March 22. 1976e p. 17. 30. Plastic World. November 19, 1973, p. 62-65. 31. **Relaforced Plastics in Chemical Plant", Brit Pleat. *43, n9, September, 1970, p. 105. ' 32. Characteristizatlon of the U.S. A shestos Paper Markets. Arthur D. Little, of Canada and Sorres, Inc. report to Government Du Quebec, Miniate're De L* Industrie et Pu Commerce, May, 1976. S3. Hentschel, Robert A., "Nome* Aramid Papers - Properties and Users", TAPPI Pap Synth Conf, Pittsburgh, Pa., October 6-8, 1975, p. 189-213. 34. Chemical Week. M&rch 24, 1976, p. 33, 36. 35. nitration. December, 1976, p. 614-620. 36. Chemical Engineering. June 24, 1974, p. 116, 119.* 37. MA shestos-free drywall joint compound utilizing attapulgite clay and asbestos substitute". National Cypsnru Patent 13907725, Septem ber 23, 1975. Si. Asbestos Dust In the Construction Industry - Technological Feasibility and Inflationary Impact Analysis, Research Triangle Institute report to Occupational Safety and Health Administration, March 21. 1977. (Draft}. 39. Characterization of the U.S, Asbestos Textile Markets. Arthur D. Little of Canada and Sorres, Lie., report to Government Du Quebec, Mlniste're De L' Industrie Et Du Commerce, May, 1976. S* 124 'f'wyr *vrrf--7r-T *s . CRMC-M&S-002899 f 6.0IMPLICATIONS OF A 0,1 FIDCR/CC . EXPOSURE LIMIT Further reducing the asbestos exposure limit to 0.1 fiber/cc will definitely have certain implications for the asbestos industry in both the primary segments (i.e., the producers of asbestos products) and the users of asbestos containing products. Depending upon each industry's perspective, there are certain options that affected firms may choose as a result > the recommended exposure limit of 0.1 fiber/cc. Such possibilities include: Seduce exposures through engineering controls to the lowest level achievable; Substitute for asbestos in the manufacturing process by using another material; Switch to competitive products; and Abandon the asbestos product line. It is not the contractor's intent to be able to categorically predict how the major segments in the asbestos industry will react to the new exposure limit, nor which industries will actually choose one of the options outlined above. However, based to a major extent on infor mation presented in Chapter S. 0, general trends were observed and some judgments can be made. It should be stressed, however, that As possibilities outlined above are closely interdependent. Many firms have already, or are In the process of evaluating the future of asbestos containing products and their own market position. 6.1 CRMC-M&S-O02900 - 111 1 L " ..............- ---------------------------------------------------------------------------------------------- `* I* I.\ - -t 6 1 Option 1: Reduce Exposure Through Engineering and Work Practices For reasons outlined in Chapter 5.0, it was concluded that for each major product segment of the asbestos industry, it is not techno logically feasible for industry to consistently maintain fiber exposure levels below 0.1 fibers/cc TWA. Therefore, according to the ancil lary requirements set forth in the October 15, 1975 proposal for 0. 5 fibers/cc, non-compliance with the permissible exposure limit would necessitate employers in all affected industries to provide respirators, protective clothing and shower facilities for employees. Additionally, all working areas would have to be designated as restricted areas. Using the costs in the previous TFA/XXS for the 0.5 fiber/cc limit which were developed on a per employee basis, the additional cost to the primary segments of the asbestos Industry is approximately $30 million, annually, computed as follows: Respirators Protective Clothing Showere Facilities Productivity Lots $ 180/man/year 175/man/year 100/man/year* 1045/man/vear $1500/man/year (x) 20,000 employees (approximately) Conceivably, these may be over estimated, for it may be pos sible for some operations within a process to maintain a 0.1 fiber/cc exposure limit. However, the contractor does not believe that the Based on total capital cost of $760/man and annualised to reflect a IS year life at 10 interest. 4.2 CRMC-M&S-002901 entire process can achieve this lower exposure limit due to the ubi quitous nature of asbestos in such facilities. Therefore, all employees actively working In the process would be at risk. Clayton Environmental Consultants did conclude that 0.2 fiber/cc was generally achievable for the primary manufacturers of asbestos products through implementation of "best technology" and strict work practice. iThe single exception to this judgment is for dry-woven asbestos textiles where an exposure limit of 1.0 fiber/ce is considered to be the lowest level achievable. The costs to achieve these levels has al ready been computed in the TFA/IZS the contractor submitted for the 0.5 flbers/cc exposure limit. However, in light of updated infor mation and recent on-site investigation of the progress in achieving lower isbtitoi exposure levels, these cost estimates will have to be modified. Such changes have not been done to date, but the contractor hilly intends to do so in the near future. Therefore, to prevent misin terpretation. tiie costs to achieve 0.2 fibers/cc as determined from the previous TFA/QS will not be presented in tills report. With respect to plant sice and a firm's ability to achieve increas ingly lower asbestos exposure limits. Clayton concludes that the control technology is highly transferable from one firm to another as It relates to asbestos fiber control measures. This is true primarily because 6.3 CRMC-M&S-002902 ....... /i (r the most effective measure* s,re these techniques which have been tried. developed, proven and refined over several years. In addition, the projected lowest-achievable fiber exposure, 0.2 fibers/cc, is actually higher than many of the reported exposure levels Indicated in the con tractors recent on-site investigations. Such observation indicated a commendable, yet generally less than best, application of available control techniques. Therefore, Clayton concludes that any major differences due to resource limitations among the industries with res pect to the timing or the extent of implementing controls will be offset in part, by an exposure level slightly greater than what conservative judgment may indicate. Finally, it is also concluded that many secondary users of asbes tos-containing products will not be able to achieve a 0.1 fiber/cc ex posure limit. The refacing sector of the aftermarket will not be able to attain a 0.1 fiber/cc exposure limit, but it would be possible to control to 0.2 fiber/cc. Zt is believed that the repackaging sector will be able <*o maintain a 0. 1 fiber/cc TWA, but that general maintenance and repair shops would have trouble with a peak exposure limit between 0.1 and 1.0 fiber/cc due to the practice of blowing out brake drums. For the secondary fabricators of asbestos reinforced plastics, paper, packings and gaskets, a 0.1 fiber/cc exposure limit is determined to be feasible, yet the associated peak exposure limit of 0.5 fiber/cc 4.4 reyr CRMC-M&S-002903  may be exceeded for the fabrication of textiles and cement sheets. Clayton concludes that a 0. 1 fiber/cc exposure limit will not be feasible nor Is it clear that any integrated TWA exposure below 0.5 will be feasible because of the machining and fabriction of these products. In all of the above cases where 0.1 fiber/cc TWA, or the peak exposure limit of 0.5 fiber/cc cannot be achieved, the employers will have to provide respirators, protective clothing and shower facilities. 6.2 Option 2: Substitute for Asbestos Chapter S.O and Appendix B cover in detail the extent of the research and development efforts to find a suitable replacement for asbestos in various product lines. However, for this discussion. It is important to make a distinction between substitute materials for asbestos in a manufacturing process and a product which competes with an asbes tos-containing product in the market. Competitive products will be discussed in more detail in Section 6.3. Almost without exception, substitute materials have been evaluated for most of the primary as- hestoe product tinea, with varying degrees of success achieved. The | ' most pronounced trend to replace asbestos was found in phenolic mol'di tog compounds where it was estimated that between 50-70% of compounds .' I previously using asbestos have now switched to other materials such as talc, elay or fiberglass. A second promising area Is in floor CUe where ; 6.5 'w-1 ...,,i!w?*7r *t * 9 CRMC-M&S-002904 1 substitutes are currently undergoing manufacturing trial* in industry to determine the correct formulations. Reported materials are cellulose fibers and a proprietary petrochemical. It is still too early to tell whether these materials will perform adequately as an asbestos re placement. Asbestos usage in friction materials Is contingent upon the success of a significant research and development undertaking by most of the major producers of friction materials to find a suitable replacement for asbestos. This work is in progress and some success has been reported, specially with regard to "organic" brake linings and woven clutch faelngs. However, it would be premature for CONSAD to conclude that a substitute for asbestos has been found for friction materials. Promising materials are on the horizon, yet a determination of when both a technically and economically feasible substitute will be available for the market cannot be made based on information obtained to date. As related In Chapter 5. 0, there has been extensive research centered on fiber reinforcement for cement products which would include both cement pipe and sheets. Development of an alkali-resistant glass to be used in these applications has generated enthusiasm in some parts of the cement industry, especially in England where this materials is presently being used to replace asbestos in cement shsets. However, there has been little interest in this country beyond the research phase t.6 '* CRMC-M&S-002905 ' 'M'' t -*  fr alkali-re si stunt |iag la replace abte>* in cement products. From the literature and conversations with industry sources, there was no reporting of alkali-resistant glass presently being used in actual cement product applications as a reinforcement. Therefore, there is uncertainty with regard to using this material as a replacement for asbestos in these product lines. Fibrous glass is the material most often identified as a substance that could replace asbestos in many of its product applications. Fiber glass used in roofing felts and pipeline felts are at present strongly competing with asbestos papers in these applications. Additionally, it may also have farther applications in certain asphalt coatings which presently use asbestos, however, it is premature to judge the extent to which such substitution may take place. Ceramic fibers have also been mentioned as possible replacements for asbestos in paper applications, such as millboard and muffler paper. There are currently ceramic boards on the market which are penetrat ing fite conveyor applications of millboard In the glasa and steel indus tries, Replacing asbestos paper with ceramic paper in muffler appli cation has only been reported In the research and development stages at this time. Asbestos-free sealants have been marketed recently end are penetrating some of the markets asbestos sealants have previously had. 4.7 -'vTTTr'yr , t ii t CRMC-M&S-002906 r t However* the extent of title trend ie not known at this time. In the pack* tags and gaskets applications* there do exist substitute materials that can replace asbestos without a substantial performance penalty in specific applications. However, there is not one material that will r( suffice for all the various asbestos uses in packings and gaskets. Furthermore, these materials are significantly more expensive than i: asbestos. Therefore, there has not been a siginificant switch to non asbestos gaskets, nor is there any indication that such will happen in L the near future. f: For the most part, materials being considered as a replacement for asbestos are significantly more expensive than asbestos fibers. There are acme exceptions, such as other inorganic materials including i: tale, mineral wool, clay and wollastinite. Fibrous glass in the majority of applications where it is considered as a substitute are on the order L of 2-5 times as expensive as the asbestos fibers used in these applica tions. There are also the "high-priced" materials such as ceramic fibers and graphite which range from 10 to 100 times more expensive than asbestos on a comparative basis. Of course, raw material costs make up only a part of the end-product price. Nonetheless, it is fair to state that by substituting for asbestos in most applications, the end price of the product will be increased. 6.8 vTWfrwfprTM1 ........1 CRMC-M&S-002907 - Another major concern in evaluating the potential to sub sti tut*.* for asbestos is the availability of obtaining sufficient quantities of alternative materials. A ease In point in exemplified by fiberglass which was noted as a possible replacement for asbestos in certain applications. Due to die recent emphasis on energy conservation by the President's Energy Plant, which stressed the need for home insulation. the demand for fiberglass apparently will increase substantially in / the corning months. Some industry sources question the ability rf the fiberglass manufacturers to keep up with demand, especially if fiber glass continues its penetration into the roofing felt and pipeline felt markets. CONSAD does not have any specific data to support this con tention; however, it is possible to concede that in the short-run, a scarcity of fiberglass could develop. Xn the long-run, the economics of supply and demand would probably ensure that a sufficient supply of fiberglass could be made available. A final note on substitutes should be made. The use of asbestos in insulation has almost ceased to exist. The health hazard studies by Selikoff in the 1960's pointed np the problems associated with asbestos in these applications. The makers of these insulation products began research and development efforts to find a suitable replacement for asbestos. Apoendlx A, as noted previously, presents a case study of Johns-Manville*s effort to replace asbestos in their molded calcium 4.9 CRMC-M&S-002908 silicate insulation products. Fiberglass has been utilized in other insulating applications, thus reducing the asbestos consumption for these products. Furthermore, the Environments 1 Protection Agency has harmed the use of asbestos in spray-on insulation applications. Therefore, for all purposes, asbestos is not to be found in most insu lation materials. 6.3 Option-3: Switch to Competitive Products A 0.1 fiber/cc exposure limit would also impact the users of asbestos-containing products by requiring engineering to control ex posures, monitoring, medical surveillance and other ancillary requiremeat*. As a general rule, where a non-asbestos product competes on a comparable cost/performance basis with an asbestos product, it will gain increasing sh&re of the market. Several cases point this out. With respect to sewer pipe, polyvinyl chloride pipe has demonstrated good performance and low cost especially in the smaller diameter pipe else* 2t has gained widespread acceptance in this market at the expense of the other pipes, including A/C pipe. In another instance, fiberglass roofing felts are penetrating the build-up roofing market in which both srjsilc and asbestos felts have been competing in recent years. Be cause installation of fiberglass roofing Is cheaper than comparable asbestos instillations and the performance characteristics are similar. 4.10 CRMC-M&S-002909 i. i\ It la anticipated th*t asbestos Celts will lose some of its market altera to fiberglass. Additionally, fiberglass felts are also a strong compet itor to asbestos pipeline felts. Over the Last few years, asbestos textile products have been losing their share of the market in dryer felts and protective clothing and maintenance cloths. Synthetic fabrics, such as nylons and the new aramid fibars, "Nomex" aro the major causes for this shift. With implementation of a 0. 1 fiber/ce exposure limit for asbertos-containing products, this trend may be exaggerated. The replacement of asbestos textiles in friction materials (e.g,, woven brakes, clutch facings) is contingent upon the research and development effort currently under way in this segment of the industry, as described in the previous section. The major end-use for asbestos-containing products is the con struction industry which accounts for approximately 70% of the total U. S. asbestos applications. Even under strict enforcement of the current 2 fiber/cc exposure limit, certain asbestos prod arts that release dust during fabrication or Installation may find lesa acceptance in certain areas. Compliance with the various ancillary requirements (e.g., monitoring, medical surveillance, record keeping, etc.) may prove to be costly to censtruaetion contractors and may force some of them to switch to non-asbestos products. Of course, there are 6.11 CRMC-M&S-002910 L' i: i ! ; r i: L L L L L r T certain a sliests-contaiaing products that do not release significant amounts of asbestos fibers and thus, would not be affected. These are: vinyls asbestos floor tile, resiliant sheet flooring, and fibrated asphlat coatings. Little asbestos exposure is observed for A/C siding or shingles, since these products are usually pre-cut at the factory and simply nailed-up, bolted, or screwed into place. However, other asbestos products that do release fibers upon installation would probably be affected. These include: asbestos cement sheets, roofing felts, and probably A/C pipe. For example, asbestos-cement sheets are now used us wall or roof panels around chemical processes where resistance to corrosive vapors is required. Some fibers are released in field installation because of the necessity to cut the panels to sise. However, the product is so unique in this application that there apparently would be contractors who would choose to control exposures and comply with the various requirements concern ing the use of asbestos products. The situation is not the same with regard to decorative A/C sheets which compete with m?ny other tyoes of paneling. Release of fibers during installation and the associated OSHA requirements may indeed force most contractors to switch to other materials, thus avoiding the "hassle" accompanying the asbestos product. Therefore, it could be anticipated that the market for A/C sheets would decline under enforcement of the current standard with 6.1Z -'>/* " Ce' * CRMC-M&S-002911 the trend bU!g exacc rab.ited by lower exposure limit* of 0. 5 or 0.1 fiber/cc. A similar situation ecu id exist in the built-up roofing market, if contractors had to comply with the ancillary requirements of OSKA standards for handling these asbestos products. This circumstance may accelerate the trend towards fiberglass built-up roofs, 6,4 Option 4: Abandon Asbestos Product Line This last option, to abandon the asbestos product line, represents the most extreme measure that various manufacturers of asbestos products could take. It is very difficult, if not impossible, for COXSAD to predict which products may he abandoned as a result of further re ducing asbestos exposures. Individual firms have made this choice in the past due to the uncertainty of their market, profitability and other considerations. The asbestos texdle industry represents a case In point ia which only three domestic producers of asbestos textiles remain, lower priced foreign imports have under cut domestic made asbestos Sextites which find it increasingly hard to compete. In 19<5 National Gypsum closed two asbestos-cement sheet plants presumably due to aa inability to justify further expenditures for asbestos dust control equipment. The advent of fiberglass roofing felts may so seriously erode asbestos felt roofs that some firms may opt to terminate Twr CBAC-M&S-002912 making asbestos products aad switch to fiberglass. However, this transformation involves a completely new change in process and is very capital intensive. Finally, if the present trend towards PVC small diameter sewer pipe continues, A/C pipe along with the other competitors (!.., vitrified clay and concrete pipe) may find their markets declining. This may force a cut-back in A/C pipe for sewer applications. Both Johns-Manville and Certain-teed make A/C and PVC pipe, so that a decrease in production of A/C sewer pipe may be compensated by increasing PVC pipe orders. However, of the four A/C pipe producers reported in last years TFA/IIS for asbestos, only Johns-Manville, Certain-teed and CAPCO remain. FUntkotc will close its A/C pipe plant at Ravenna, Ohio if no one buys it. 414 CRMC-M&S-002913  7.0 FEASIBILITY OF MONITORING ASBESTOS m THE WORKPLACE ENVIRONMENT IN THE 0.1 - 1.0 FIBER ICC RANGE 7.1 Background and Objective la October, 1975, A Occupational Safety and Health Administra tio (OSKA) proposed a reduction in the permissible limit for asbestos exposure to 0.5 fiher/ec for as 8-hour time-weighted average exposure (fibers > 5 am in length). The proposal also included a correspond ing reduction in five ceiling exposure limit from ten to five fibers/cc as determined over a period of up to IS minutes. % December, 1976, the National Institute for Occupational Safety and Health (NIOSH) recommended to OSHA that no worker be exposed to an airborne concentration of asbestos in excess of 0.1 fiber/cc on an 8-hour time-weighted average basis and further, that no worker be exposed to peak concentrations in excess of 0.5 fiber/cc based on 15minute sampling periods. An extremely important aspect of these proposals concerns the feasibility of monitoring asbestos exposures in the workplace at air borne concentrations below one flber/ce. The suitability of any monitor ing method associated with and incorporated within an exposure standard is fundamental in at least two basic respects. First, an environmental standard has meaning only If eirborae concentrations can be measured 7.1 wi*s wi CRMC-M&S-002914 M'. t l r i ( I I it i* i. I ! L ( t i. ? t. i. ,! ... r L. t 1 reliably o that quantitative indices of exposure have a common, widely accepted, well-understood meaning to all interested parties -- health agencies, industry, the work force at risk, indeed the general scienti fic community. This is a fundamental concept that applies in the promulgation and application of any standardized measuring method, and it certainly applies in die case of the sampling and analytical methodology used to document worker exposures to airborne asbestos in the occupational setting. Secondly, in die context of this study, die asbestos monitoring method has special meaning as it relates to the technological feasibility and economic impact of die proposed exposure limits. Technological feasibility and economic impact are closely related in this sense, especially widi respect to die number of samples to be taken and the length of campling and analytical times associated with measuring the workplace environment to (a) judge compliance with the proposed standard and (b) fulfill die on-going monitoring requirements set forth explicitly in the proposed rulemaking. 7.1.1 The Role of Monitoring The Occupational Safety and Health Administration's notice of proposed rulemaking in the Federal Register of October f, 1975, states in Paragraph E. .. "The purpose of aU monitorlag required by this paragraph is to measure accurately the airborne concentrations of 7.2 CRMC-M&S-002915 asbestos fibers in a workplace to which employees would be exposed if they worked in the area without use of personal protective equipment such as respirators, Monitoring shall be performed in a manner reasonably calculated to satisfy this purpose." The proposal also specifies initial monitoring by every employer where asbestos fibers may be released, and, in those cases whs re exposures exceed die limits proposed, monitoring must be repeated every month except where two consecutive monitorings made at least five days (but not more than three months) apart show employees' exposures to be below both limits. In this instance, monitoring need net be repeated except for those operations where modification* in production, process controls, or other relevant factors would "lead the employer to believe" that an employee's level of exposure may be above die limits prescribed. The recommended sampling and analytical method set forth in the proposal is the "USPH3/NIQ5H Membrane Filter Method for Eval eating Airborne Asbestos Fibers", a draft report by Nelson A. Liedcl, Stephen O. Bayer, Salph D. Zumwalde, and Kenneth A. Busch, invest!* gators within NIOSH,*1* 7,1,2 Criteria for a Monitoring Method The basic requirements for any monitoring method used to docu ment environmental exposure include the following* 7,1 wtw,r.ffttr 'wfi'YSWs* CRMC-M&S-002916 e Specificity - the extent to which the method can specifically identify the material of interest - in this case, asbestiform fibers. Sensitivity - the degree to which the method can be used to characterize very low concentrations of fibers in air and, in that sense, the lowest feasibls concentration of fibers which can be documented reliably with the procedure. Accuracy - the extent to which the method provides a true estimate of the concentration of asbestiform fibers of the diameter and aspect ratio of interest present in the air and represented by the sample. Precision - the extent to which the measurement can be reproduced with reference to a single investi gator and different investigators analyzing the same sample. These criteria have special moaning in the case of asbestos because of the evolution of a monitoring method - namely the NXOSH method -- where serious concern has been expressed with respect to all of the criteria identified above. These concerns will surface throughout this report and to that extent, they can be used as a thread of continuity relating this disucssion to die technological feasibility and economic impact of the monitoring aspects of the proposed rulemaking. T.l.S Purpose The purpose of this analysis is to esamiae the feasibility of monitoring airborne asbestos in the workplace environment in the 0.1 - 1.0 fiber/cc range. This mmiiutiea includes a critical review of current monitoring practices as they relate to those procedures T.4 -r i TT CRMC-M&S-002917 associated with the proposed standard and a discussion of critical issues yet unresolved with respect to the specficity, sensitivity, accuracy, and precision of alternative sampling and analytical methods, generally, and the NIOSH monitoring method stipulated in the rulemaking, speci fically. 7.2 Summary and Conclusions With all its shortcomings, the NIOSH phase-contrast method is the only monitoring technique for asbestos that can be uecd routinely and widely at a reasonable cost. Despite its limitations in specificity, sensitivity and precision, this method has been used in conjunction with the more recent epidemiological studies on occupational exposure to asbestos. Any change in the method for monitoring asbestos must be coupled with a corresponding review and reevaluation of the epidemio logical data base. The NIOSH monitoring method can be used to measure asbestos concentrations at or below those levels stipulated in tha proposed rule making. Nevertheless, only a certain combination of sampling pumps and microscopes can be used to achieve an acceptable range of surface fiber density on filter samples. The precision of fits NIOSH method has not been defined adequately -* qualitatively or quantitatively -- so as to Include die random errors ?.S * CRMC-M&S-002918 associated with fill components of ths total sampling and analytical process. Ths published NIOSH assertions concerning precision of the method are not consistent with the "total coefficient of variation" for other NIOSH monitoring methods. It is our judgment that they under estimate the coefficient of variation in a likely-significant, stillundetermined manner. The relatively large confidence interval associated with measured airborne concentrations detracts from the meaning and conclusiveness of estimated exposures at low levels. This relative '^precision becomes Increasingly important at decreasing concentrations. The magnitude and impact of this problem cannot be measured exactly until ths relationship between fiber counts on a given filter and coefficient of variation fCV) is defined empirically in a rigorous manner. Based upon our best estimate of the precision of the NIOSH monitoring method at concentrations at or below 0.5 fiber/cc, the determination of compliance or noncompU&ac with a standard in this range will be diffi cult and will likely require counting large numbers of fibers on samples with low surface fiber deneitiee. Even under such conditions, the conclueivenese of exposure estimates in this range of concentrations must be qualified due to the high degree of statistical uncertainty. T.b $i '8 >s CRMC-M&S-002919 -;C' 7. 3 Alternative Analytical Methods The following paragraphs present brief summary comparisons of the various analytical methods used to measure asbestos. For more detailed information, reference is mr.de to the latest NXOSH release on die subject "Revised Recommended Asbestos Standard, " NIOSH Publication Number 77*169, December 1976. 7.3*1 Light Microscopy The cur*at, standard asbestos monitoring method -- that endorsed by NIOSH -- for quantifying occupational exposures is the visual counting of fibers on membrane filters using phase-contract microscopy. The air to be sampled 'is drawn through a cellulose acetate membrane filter at a known flowrate and sampling duration. The filter is then sectioned, placed on a microscope slide, and rendered transparent by an ester-based mounting medium. The sample is examined at a magnification of 400 to 450X using phase-contrast illumi nation and a standard reticle. The number of fields of the reticle to he evaluated varies from 20 to 109 or more for each sample, depend ing upon the dust loading. The technique requires considerable train ing, skill, and patience, and ia thus subject to operator error. In comparative evaluations of possible alternative methods, specificity is a glaring weakness of the phase-contrast method and a 7.7 wrfTv CRMC-M& S-002920 distinct advantage for most other techniques such as X-ray diffraction and electron microscopy. It is virtually impossible to assess the "accuracy" of the phase- contrast method, that is, its capability to estimate or measure at or very near the '^actual" level, because of the extreme difficulty in generating known concentrations of asbestos fiber for "calibration" purposes. - 7.3,2 Electron Microscopy Electron microscopy has great advantages over light microscopy la farms of higher resolution. This permits derivation of morphological information which can be used for positive identification of asbestos. For instance, chrysotile fibers exhibit characteristic center channels, and most asbestos fibers break in a manner such that the ends are fairly characteristic. However, these effects are not sufficiently specific to provide positive identification in all cases, making additional characterisation necessary. This may include X-ray fluorescence and selected area electron diffraction techniques. h scanning electron microscops (SEM) analysis, filters are first vacuum coated to make them conductive. The frequency of fibers that display X-ray fluorescence characteristic of asbestos are then measured against standa?ts. 7.9 'VP f CRMC-M&S-002921 ++*V'' it' v The transmission electron microscope (TEM) coupled with selected ares electron diifrection (SACO) represents s powerful ana lytical tool for asbestos determination, m cases where diameters of the fibers can wry over a wide range, SEM is preferable. The TEM is unable to cope satisfactorily with a wide range of diameters. Although electron microscopy offers the advantage of achieving positive, accurate identification of any crystalline fiber by its electron diffraction pattern, with good sensitivity, the analysis time is rela tively loag. Processing time typically exceeds four person-hours per sample. The required Instrumentation is also prohibitively costly for widespread, routine usage. * 7.3.3 Infrared Spectrometry A technique based on the absorption of infrared radiation (IR) at 2.72 am wavelength has been reported in the literature. ^ This absorption is associated with the stretching vibration of hydroxyl gr oups bound to the silicate structure and Is well separated from the absorption bands that are due to water. Although water does not inter fere in the analysis, a large number of common minerals such as Electron microscopy instrumentation with elemental analysis capability cost roughly $2SO, 000 as compared to $1,000 for the phase contrast method bulrttmaats. 7. it ,i * CRMC-M&S-002922 <1 aontibroui serpcntinos, clays, micas, and talc can be expected to give false positive signals and may mask the chrysotile peak. The infrared technique is fairly sensitive, and may be useful in certain low-inter ference environments. XI also has the advantage of being relatively simp! and rapid. 7.3.4 X-ray Diffraction Dost samples collected on a filter or impaction surface can be identified and quantified by characteristic diffraction patterns which result from X-ray scattering by the crystalline compounds in the sample. Diffraction angle and intensity, respectively, ei' * fes used to Identify and quantify the asbestos in the dust sample. Sensitivity is marginal, and morphological information is virtually nonexistent. Not withstanding its sensitivity, die lack of interferences and the adapta bility to automated oparation make this method attractive. 7.3.5 Dispersion Staining ft has been proposed that die outer Mg(OH>2 surface of the asbestos fibers might be stained with a selective dye after sample collection and die asbestos then be estimated by spectrophotometry or, alternatively, be more easily counted optically because of the enhanced contrast. Dispersion staining is one of the most promising techniques for fiber analysis, ft is not significantly more expensive than the phase 7.10 w**t,yTfi iwiiptn . * -\ CRMC-M&S-002923 \ '** * % !* * contract microscopy* but offers the sdvsntsgo of specificity. The equipment is not much different then thst used for phase contrast methods* however* this technique requires somewhat more operator training? ?*3*i Thermoluminescence Tfcermoluminoccence (TL) is the characteristic luminescence emitted by a stressed material as it relaxes when heated, X or gamma radiation is most often die energy source used for including the stress. Subsequent heating of die material releases some of the absorbed energy in the form of ultraviolet or visible light. TL data are commonly pre sented in die form of a glow curve with luminescent intensity exposed as a function of temperature. Temperatures at which peaks occur in the glow curve and the wavelength of the luminescence are related t& structural imperfections in the material. If sufficiently characteristic, die glow peaks can be used to identify the material. Differential thermal analysis has not been used for environmental samples as lower limits of mass detection are extremely poor. This technique, like X-ray diffraction, is not capable of differentiating between asbestos fibers and their nonfibrous mineraloglc polymorphs. 7.11 -"i,v.... 4* - # C RMC- M& S -002924 M * V' i 7.4 NIOSH Asbestos Monitoring Method 7,4. 1 Historical Development The first published nraion of the membrane filter method* as used by the forme; Division of Occupational Health lUSPHS). was that of Eduards and Lynch in 1968. ^ Bayer and Zumwalde of NIOSH assembled a more detailed version of ifcs membrane filtercount method In 1972 based on material prepared for us in a NIOSH training course covering sampling and analysis of airborne asbestos dust. ^ Leidel. Bayer* and Zumwalde prepared a more detailed version of the method in 1973 for submittal to the American Society for Testing and Materials Committee K2.64. ^ This report u also used in NIOSH training voarsm, 'bat-was -never formally published by NIOSH. The 1973 report confateitd the first NIOSH estimate of the method's precision on the basis of a limited study published by Conway and Holland in February. 1973. (6) Several subsequent draft versions of th NIOSH in-house report have been circulated informally, although no final report has been published to date. In late 1973. after the publication of the OSHA-proposed reduction is the asbestos standard. Leidei et U of NIOSH once again revised the asbestos-count method. ^ The latest ia*house draft of the NIOSH method known to CONSAD/Clayton is that dated June. 1977. <> 7.11 CRMC-M&S-002925 7* 4*2 Scope and Summary of NIOSH Method Samples are collected by drawing air through a cellulose-ester membrane filter by moans of a battery-powered personal sampling Sramp. After sampling, the filter is transformed from an opaque, solid membrane to a transparent, optically homogenous gel. The fibers are sised and counted by phase-contrast microscopy at 400 - 45OX magnifi cation* This method considers only fibers with a length to width ratio of 3-to-t or greater and a length greater than five micrometers. Thus, it is intended to give an index of exposure to airborne asbestos fibers of specific, yet limited, dimensional characteristics. The method has been successfully applied using 3?-mm Millipore AA filters and small battery-operated personal sampling pumps at flowrates of 1.0 to 2. liters per minute (lpm) for time periods of a few minutes to 150 minutes over a concentration range of 1 to 20 fibers/ ee. Large deviations from these conditions can result in samples with either too few or too many fibers, which can yield air concentration estimates of low statistical precision and accuracy* 7*4*3 Application of NIOSH Method at Low Concentrations The feasibility of monitoring airborne asbestos levels In the workplace at very low concentrations (below 1.0 fiber/cc) depends heavily on two important characteristics of the sampling and analytical 7.13 /tf '-V CRMc-m&s.002926 ,111 - 111 nd in iTiTi methods sensitivity end precision. Sensitivity relates to the sampling time* pimp flowrate, and counting procedure needed to determine fiber concentrations at or below the prescribed concentration limit, whether it be 0.1, 9.1, 9.5, or some higher level. The certainty of decisions resulting from a comparison of measured concentrations i% i with the prescelbed limit is reflected in the variation Of precision of the sampling and analytical method based on its random srrors. The empirical precision of the phase contrast method presents the crus of the problem with die NIDSH monitoring method. The vonfidence level attached to an environmental measurement, including asbestos concentrations, depends greatly upon the ability of an investi* gator using a standard method to obtain reproducible results. In general, this question has been overlooked to a great extent until the recent past when the question of compliance and/or noncompliance has become more Important. Such determinations now must be tested in i a legal settee with the result diet methodology and analyses mist become mere defendable. and therefore, more rigorous. Phase contrast L. counting of asbestos fibers is notoriously troublesome with respect to r' reproducibility, and in die heightened concern over the movement toward a redaction he die asbestos fiber standard, the precision (or j Imprecision! of the sampling and analytical techniques as a whole mast be recognised hilly* * 7. Id t CRMC-M&S-002927 2b recent years, NXOSH has conducted and published statistical research on the types of variation affecting occupational health related environmentsl monitoring methods. Leidel and Busch have developed procedures that describe the calculation of confidence limits for the /o) true airborne concentration of a contaminant. Xn 1975, these investi gators published recommended procedures in a NXOSH report for the collection and evaluation of sample results to determine if the state of aoneompliance with an occupational health standard exists. {10) The NXOSH monitoring method is best suited for a filter surface fiber density in the optimum sons of one to five fibers/field. For typical conditions, with an exposed filter area of 855 mm^ and a field area of about 0.003 mm*, this means that the optimum sampling arrangement would yield at least 285,000 fibers during the sampling period. Zf the true airborne fiber concentration were 0,2 fiber/cc, this means that an optimum sample volume would be about 1425 liters. At a typical flowrate of 2.4 liters per minute, this corresponds to a sampling time of about 704 minutes. Therefore, by NXOSH's own description of the procedure, the method must be modified to extend the "optimum" surface fiber density range below one fiber per field to be compatible with even fnll-shi^t (8-hour) sampling using conventional sampling equipment. 7.15 7T I I * CRMC-M&S-002928 i The NIOSH draft method of November, 1975 (that published just after OSHA proposed a reduction in the standards) states "the optimum fiber density should be one to five fibers per microscope counting field, In the latest draft method (June, 1977) the acceptable range of surface fiber density has been extended, but without any rational or documentation to support such an extension. The latest draft states "feasible counting conditions may extend down to about 0.1 fiber/field and up to 5.0 fibere/field. The impression is given that the range sms extended downward to 0.1 fiber/fieId to accommodate the proposed toducfelons in the standard to 0.5 fiber/cc and below. 7.S Statistical Interpretation of Monitoring Results 7,5,1 Sources of Error and Measures of Precision The latest draft of the NIOSH method presents the NIOSH inter pretation of the major sources of variation in the procedure. ^ The following table summarizes that interpretation. The relative variation or dispersion of a normally distribution data set (such as the random variations in a sampling and analytical procedure) Is commonly measured by the "coefficient of variation (CV)". The CV Is also known as ths relative standard deviation. It is calcu lated by dividing die standard deviation of the data by the arithmetic average. The CV is a useful parameter of dispersion in that limits 7.16 CRMC-M&S-002929 H'.y.w.-ysT*'*-'-' W",*--...---- i i ' 'if' ..........' Source of Variation i. lot ref11cor (cooeieting of lauttltU within a wedge eod tncerwedge wlthlo flltar) s. Interfiiter (wlthlo a. faecrleboratory s. tnvireaaeacol Possible Causes end Nature Tho counting prteifurt only *im> plea" and aatlwacas tha filter aurfact fIhor density. Ktnloa variations with soon likelihood of saall systeaatie blaaoa hatwaaa wadgoa shite: con be created os roodoa. Sees randoo vartatieos ostae, but dif foraneaa are* prlaarlly systeo* Stic due to improper training, lack of experience, attitude, poor visual acuity, or so quality S9B Seal pragraao. fluctuations in puap flowrate. Systeaatie blaaoa due to tapropar puap eallbratioe. Sjrstaaaelc variaeloas due te it( foresees in alcroseope quality ced specifications, iaproper aicroscopc adjustment, couatet training, er iaproper application of tho aothod. Both randoo variations and syseceatie biasaa dua to coneantratioo changes in tlaa aad space. eoasis ting of fee true raemn of a data set, plus or minus 1.645 ft* standard deviation, will contain about 90 percent o* the data measuremorns, TMs is a rough approximation that depends on the number of data values from which the mean and standard deviation were calculated. Correspondingly, if an analytical procedure with a known CV of 0.20 were used to measure repeatedly some fined physical property, then about 95 percent of the measurements would fell within plus or minus 40 percent (twice fee CVj fee true concentration, assuming an unbiased measuring procedure. 7.17 ""vrwTrvyyf it t CRMC-M&S-002930 Ui' * 1- - The most critical iaauea in the feasibility analysis for the N1Q3H monitoring method and its intended application are (1) the definition of "eosfficitnt of yirktisM as it relates to the monitoring method for asbestos* and (Z) the value of CV for the method as it affects sampling and analytical time and the corresponding expenditure of resources. For some -- yet unexplained -- reason* it is NIOSH's position that the CV for the asbestos count method should measure and include only the net variation associated with the sources of a random error described above. Obviously* however, the coefficient of variation claimed by NIOSH la based oa only some of the random errors encoun tered during the analytical method. Other NIOSH methods included in the Standards Completion Projects* for example* include methods for which the coefficients of variation have been based upon sampling and analytical errors. NIOSH has maintained consistently* throughout its reports and in the record, that its recommended asbestos monitoring procedures can 'Adequately and confidently" monitor and describe compliance with the OSHA-proposed asbestos standard of 0.5 fiber/cc and the NIOSHrecommended level of 0.1 Uber/cc. Based upon the evidence and the record, however* it seems clear at this point that the coefficient of variation for the asbestos monitoring method using the NIOSH-proposed technique has not been evaluated in a rigorous way that can be supported 7.19 v '.M'.r* j* '.`"Trwvwr t CRMC-M&S-002931 T by even the various* semi-objective scientific interests that surround this issue. Further, it is Clayton's judgment that the NIQSH coefficient of variation estimate of 0.24 is too low because it is Incomplete. The resolution of this question will depend upon: (1) agreement concerning the definition of coefficient of variation as it relates to the asbestos monitoring method, and (2) the timing and quality of a carehlly designed study that will measure the various relevant components of variation in the total sampling and analytical process. It does seem reasonable, in the meantime, that as a minimum consideration, the definition of CV be consistent with the definition used in the develop ment of other sampling and analytical methods, specifically the defini tion of coefficient of variation associated with other NIOSH-proposed sampling and analytical methods. 7*5*2 Determining Compliance and Noncompliance KIOSH ha* proposed a procedure for determining compliance or aoncomplfcur;* with exposure limits using workplace sampling schemes of the following variations: (11 single eight-hour sample: (11 several consecutive samples totaling eight hours; (3) several consecu tive samples totaling less than eight hours: and (4) grab samples. ^ The caicuiational procedures useful for determining compliance in the simplest of these sampling schemes are described briefly below, to Illustrate the critical nature of the coefficient of variation of the sampling and analytical method. 7,19 CRMC-M&S-002932 'rmrrrm+vr,* 'wrw ........................ * A\r Terms and Abbreviation* The airborne asbestos fiber concentration estimated by counting wedge of the filter sample is calculated as follows: AC fiFB/FL) - (BFB/BFUl (ECA) 1000 (FR) (AT) (MFA) where: AC * Airborne fiber concentration, (fibers > 5 *m)/cc. BFB * Total number of fibers counted in t&ie BFL fields of the blank (control) filters, fibers >5 anu BFL * Total number of fields counted on the blank (control) filters, SCA a Effective collecting area of filter, mm*. H a Ramp flowrate, liters/min (1pm). FB a Total number of fibers counted in the FL fields, fibers >5 am. FL Total number of fields counted on the filter. UFA a Microscope count field area, mm2 (generally 0.003 to 0.006). AT Sample collection time, minutes. Other terms useful in describing the statistical methodology include: CV a Coefficient of variation for a sampling and analytical method at condition* characteristic of a given mea surement. LCL a Lower confidence level for AC (normally at 95% significance with statistical coefficient of 1.645), fibers > S jun)/cc. 7.20 TFr,*"~rn" , v v CRMC-M&S-002933 j" "r~n -- 9 SE * Standard error of TWA * (d V * ) STD * Exposure standard, (fibers > 5 sm)/cc. TWA 8 Time-weighted average fiber concentration, (fibers > 5 >m)/cc. UCL * Upper confidence level for AC (normally at 95% significance with statistical coefficient at 1. 645), (fibers > 5 m)/cc. V TWA variance based on N samples (SE^>. Procedure for Single, Full-Shift Sampling 1* Obtain AC and CV, AC is the estimate of the airborne fibs? coceentr&iiea (/ee) calculated from the total fiber count (FB), CV is a function of total fibers counted (FB). Because values of CV are not defined adequately, reference is made to the general expression: CV e f (FB) 2. Calculate UCL or UCL: Compliance officer's test for noncompliance. LCL (95%) * AC - 1.645 (CV) (STD) Employer's test for compliance. UCL (95%) * AC 1.645 (CV) (STD) 3. Classify exposure estimate: Compliance officer's test for noncompliance. If LCL > STD, conclude "noncompliance" if AC > STD and LCL < STD, conclude "possible noncompliance" if AC < STD, no statistical test for noncompliance is needed Employer's test for compliance. if UCL < STD, conclude "compliance" if UCL > STD, conclude "possible noncompliance" 7.21 *7*17*"-: r,T* --wvrtvr," CRMC-M&S-002934 Example; 1. An airborne asbestos fiber level of about 0.2 f/cc was suspected. A phase-contrast microscope with * a count field area of 0.003 mm2 and a pump calibrated lor 2.0 Ipm are available. When a filter wedge was counted, the total fibers counted in 100 fields was 58. No fibers were found on the blank filters. Assume (for purposes of illustration) that CV 0.4 for 58 fibers and STD *0.2. AC 58/100) (855) * 0.17 f/cc a (1000) (2) (480) (0.003) 2. LCL (95%) 0.17 - (1.645) (0.4) (0.2) = 0.04 UCX, (95%) * 0.17 4- (1.645) (0.4) (0.2) 0. 30 3* Since AC * 0.17 U less than 0.2, a conclusion of "noneompliaace" is not warranted* Since 0.30 (UCX.) exceeds STD, an employer should conclude "possible noncompliance'' Although these calculations! procedures are similar, yet somewhat more complicated for other sampling schemes, such as consecutive sampling and grab sampling, the parameter CV remains a crucial aspect of the statistical interpretati on of monitoring results. 7.6 Feasibility Analysis Both the technical feasibility and costs of monitoring airborne asbestos in the workplace with reference to very low exposure limits (<1.0 flbsr/cc) depend on the incremental and overall feasibility of each stage in the sampling and analytical procedure. Two basic 7.22 r*,* l,n.,y,w. ` i V' CRMC-M&S-002935 F characteristics determine such feasibility,, however, the sensitivity and precision of the monitoring method. 7. 6, 1 Sensitivity The importance of sensitivity in this context can be examined by looking at the logistical and calculations! steps needed to sample, count. and compute fiber-concentration estimates at or below the prescribed exposure limits. Minimum detectable fiber concentrations derived from phase-contrast microscopy depend directly on sample volume, microscope field area (MFA), number of fields counted, and the presence of absence of noadbrous particles. Theoretical minimum detectable concentrations can be computed by assuming one fiber > 5 jun ia length is observed in 100 counting fields. At a sampling flowrate of 2.0 1pm (FR), using an exposed filter area of S5S mm^ (CA), these data can be expressed as follows: Mlniaua Oececcsblc Fiber Concentration ( Sampling Period (fibers > 5um) 'cel t (alnutes) MFA - 0.003 an2 MFA 0.005 ran-2 1 MFA 0.007 nn^ r 15 I i 30 40 90 120 240 340 480 0.10 o.os 0.02 0.02 0.01 0.004 0.004 0.003 0.04 0.03 0.01 0.01 0.007 0.004 0.002 0.002 0.04 0.02 0.01 0.007 0.005 0.003 0.002 0.001 t 7.23 CRMC-M&S-002936 . * 'W'Vi'Tt /* ** The NIOSH method, however, cells for the analyst to count no less than 10 fibers or no less than 20 fields. At very low concentrations, therefore, the route to adequate sensitivity using the NIOSH method is to count enough fields to reveal at least 10 fibers after discounting the control sample. This can be done at a higher time expenditure, only if enough fibers have been collected on the filter sample. Today's state-of-the-art in personal sampling equipment for docu~ t mooting workplace exposures provides wide access to sampling equip* most which operates in the range of 1.5 to 2. S liters par minute. Because the membrane filter used for sample collection in the NIOSH method has a relatively large resistance (pressure drop), sampling pumps typically run at a rate of 1.5 to 2.0 liters psr minute, although some configurations may be available at higher rates, such as 2. 5 liters per minute. Suppose a peak exposure of 0.5 fiber/cc or more is suspected for ohort periods up to 15 minutes. Using a calibrated pump at 2.0 Ipza, an industrial hygienist samples the breathing none of the worker for 15 minutes using a J7mm membrane filter. Assume this laboratory uses a phata*coatrast mlcroacops with MFA * 0. 004 mm*. Tha filtar collection area (855 mm*) contains about 214,000 fields. Tbs $0*liter air sample will contain 15,000 fibers if file concentration (AC) is 0.5 fiberfee. The surface density of fibsrs in the sample will 7.24 CRMC-M&S-002937 be 0*07 fiber/field, however, somewhat less than the lower bound of fise acceptable range, 0.1. The following table shows the surface fiber density aehieveablc using various sampling/analytical configurations for a 37-mm filter and a 15-minute sampling period and airborne fiber concentration of 0. 5 fiber/cc* Pleurate dpn) 1.5 2.0 2.5 3.0 1 3> Surface Fiber Density Achievable (FB/FL) M FA (rsO 0.003 0.004 0.005 0.006 0.007 i 0.04 0.05 0.07 0.08 0.09 0.05 0.07 0.09 0.11 0.12 0.07 0.09 0.11 0.13 0.15 0.08 0.11 0.13 0.18 0.18 0.09 0.12 0.15 0.18 0.21 This table shows elearly that only a certain combination of sampling (pump) and analytical (microscope J instruments can be used to achieve a minimum surface fiber-density of 0.1 fiber/fisld for 15-minute sampling with reference to the NIOSH-propoaed ceiling concentration of 0.5 fiber/cc. Thus, economic costs of monitoring asbsstos, bsssd on sensitivity considerations only, relate to the limited configuration i of instrumentation acceptable as well as the costs of props ring and I counting filter samples. Tha requirement and advantage of higher i-- I ?.* CRMC-M&S-002938 id 'flHfN.* ................... ' ' I*? 'Otfc flowrate pumps with regard to sensitivity suggest that a new generation of sampling equipment will be necessary to conform to the require ments implicit in the 0.1 flber/cc (8-hour TWA) and 0.5 fiber/cc (15-mlnute peak) NIOSH proposal. The surface fiber density estimates must also be considered in light of die fact Out the method requires each illt.er prepared for count ing to be relatively free of other background particulates. In many industrial applications, even within the prim&ry asbestos industry, othsr dusts -- fibrous and nonfibrous -- will be prewent. In effect, therefore, longer sampling times such as those lasting ssveral hours are not necessarily consistent with the NIOSH method because of the likelihood of overloading the filters with background particulate that will interfere in She counting procedure. 7.6.2 Precision Section 7.6.1 discussed technical feasibility of monitoring air borne asbestos in terms of minimum detectable concentrations (sensitivity) and conditions conducive to collection of minimum required numbers of fibers in given sampling schemes. "Precision" repre sents another extremely pertinent characteristic of the NIOSH phasecontrast monitoring method in the context of technical feasibility. The confidence interval associated with a given estimate of fiber concentra tion dictates the extent and conclusiveness with which comparisons with 7.26 CRMC-M&S-002939 permissible exposure levels can be made sad, moreover, the cost* benefit of resource expenditures needed to narrow the confidence levels (strengthen the conclusiveness) el exposure estimates by improving the precision of the monitoring method in any given application. The most critical issue here, as explained in Section 7. 5, is the definition -- quantitative and qualitative of the variability in the method from random errors, Le,, the coefficient of variation (CV). NIOSH has conceded, on the basis of its latest in-house draft of the monitoring method report that CV is not a fixed value (formerly asserted to be 0.22), but a function of total fiber count, FB (see Figure VH-1).*8* Theoretical and empirical considerations suggest that CV decreases for larger numbers of fibers counted and increases for counts (FB) of smaller magnitude. It is our judgment that, as of this time, no adequate research has defined CV for the phase-contrast method as to include the random errors associated with the entire sampling and analytical procedure. Clearly, the NIOSH estimates to date are incomplete and very likely too low. (See Section 7. S.2) For purposes of illustration, however, various levels of CV can be assumed so as to demonstrate the importance of this parameter in the context of feasibility. Because no one has yet. In our judgment, rigorously determined the coefficient of variation of the NIOSH method T.27 CRMC-M&S-002940 v>irti *rr,f" --....................................... ** # * .> ;% Mr ' Jr* * CRMC-M&S-002941 TOTAL FIBER COUNT -- FW tW.S by a well-designed empirical process, one must discuss feasibility at this stage la terms of assumed levels of CV. It appears likely from our analysis of the literature and various positions of advocates of one cause or another in these circumstances, that a range of 0.3 to 1.2 wUI likely bracket the "true" CV, at least for fiber counts of 20 or greater. A relationship CV * (FB) will undoubtedly be determined ultimately, and after peer review and comment in the scientific litera ture, be accepted as an estimate derived by a consistent, rational approach. Suppose a sample of air is drawn at 2.0 1pm for a full-shift (480 minutes) sample for comparison of the measured exposure with As permissible TWA. Assume die FB/FL ratio is 0.40 (for example, i SfefF la 125 fields). Assume, (from a yet uncompleted, definitive study) diet CV 0.6 at FB * SO. From Section 7.5.2, assuming BFB/ BFL * , ECA * 855 mm2, and MFA * 0.006 mm2, AC (0.4) (855) 0.06 fiber/cc (1000) (480) (2) (0.006) then, LCL IfCL 0.06 1.645 (0.6) * "-0.93" fiber/cc 0.06 1.645 (0.6) 1.0 fiber/cc The f5% confident interval associated with this exposure estimate of 9.06 fiber/cc thus ranges from 0 to 1.0 fiber/cc. Clearly, an employer eould not form a definitive conclusion on the magnitude of the exposure 7.2f v;w,r"nyyr CRMC-M&S-002942 f TT rtUtiw to a TWA permissible limit less than one fiber/cc. The only alternative to strengthen the conclusion is to minimize CV within the constraints governing the collection and analysis of that sample; this can only be done by counting more fibers. I. The importance of CV for the ease of shorter than full-shift sampling periods is illustrated in the following example where several consecutive samples cover a full-shift (eight hours). An industrial hygienist whose laboratory has a microscope with r 24JFA * 9*096 mro* samples a worker's asbestos exposure with a pump i. L' calibrated at 1.9 lpm and filters with ECA * 8S5 mm2 . Results are as fsUoursi i * ATi ainutes fLi FBi/FLt ACi (f/cc) cvt* 110 40 120 0.33 0.23 0.62 125 45 100 0.45 0.28 0.59 130 85 130 0.50 0.38 0.51 115 55 110 0.50 0.31 0.55 ^Values assuned for purposes of illustration <0.38)4.(113^0.M2 . 0 30 f/e) [? TWA variance 12 (ATi)(ACt)(CVi) 1 480 J i-i L 7.30 CRMC-M&S-002943 'y.Ty?*"y'Wg'y' .i i t 'ifr ;,^0' V * 0.001068 * 0.001851 0.002755 0.001669 0.097342 IS Standard error of TWA fv1 * 0.086 f/cc LCL(95%) 0.30 - 1.64S (0.086) * 0.16 f/cc OCX. (95%) 0.30 f 1.64S (0.086) >0.44 f/ee Therefore. It la obvious that ths rang* confidence interval of tho method nut bo taken Into account in determining the compliance, or. non* compliance of a workplace environment. T. 7 Questions Concerning the NXOSH Phase Contrast Method Several questions remain as to the rationale for the NXOSH Insistence that CV is adequately defined for the method on the basis of Pifure Vn-1,, NXOSH has stated that ths coefficient of variation (CV) for the asbestos count method should include (measure) only random intrafilter variations (Isisr-fiald within a wedge and interwedge within a filter), random lnter*ounter variations, and random pump flowrate variations. *** Zs this "definition" of a "total coefficient of variation" really consistent with other NXOSH*recommended monitoring methods? For example, is this definition consistent with that used in the SRI Standards Completion Project Contract (CZ3C-99*74*45)? T.S1 rr7- "" mmrr^n CRMC-M&S-002944 Why does the N10SH definition of "total coefficient of variation" lor the asbestos method not include random errors associated with filter preparation (loading and unloading) and filter wedge mounting after sampling but prior to counting? Because the coefficient of variation estimated by s/x inherently ^asimatiEMtesithtSsise'sodk^a& mfm Cpite meamvsdiMe n ^autbo iss less than the. ratio of the true means), why haven't the NIOSH investi gators corrected for this bias in estimating CV? 7.12 ' ** ' ,7 'l t *f * CRMC-M&S-002945 i. e ` ' ' 'r+S ' ' M -r*> MMM ,112 7,8 Itferincei 1. LiUel, N,A, t 3. G. Bayer, 8,0. Zumwalde, end K. A. Busch, "USPHS/NIOSH Membrane Filter Method for Evaluating Airborne Asbestos Fibers", U.S, Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Cincinnati, Ohio 4S226 (Undated Draft Report). 2. Cadaen, J,A,, J. Parker, and W, L. Smith, Atmos. Env. 4. 667 <70). 3. Edeardst C.H. and J.R, Lynch, "The Method Used by the U.S. Public Health Service for Enumeration of Asbestos Dust on Membrane Filters", Ann, Occup. Hyi.. U., 1-6 (1968). 4. Bayer, S.C. and R.D. Zumwalde, "Evaluating Airborne Asbestos Dust", NIOSH In-houss Report (July, 19721, 8. Leidel, N.A., S.C. Bayer, and R. D. Zumwalde, "USPHS/NIOSH Membrane Filter Method for Evaluating Airborne Asbestos Fibers", NIOSH unpublished In-house Report TR-14 (November, 147)). 6. Conway, R.Ec and W. D. Holland, "Statistical Evaluation of tht Procedures for Counting Asbestos Fibers on Membrane Filters", LFE Corporation, Richmond, California (Prepared lor Asbestos Information Association/North America (1971)). ? beidel, N.A., S.C. Bayer, and R.D. Zumwalde. "USPHS/NIOSH Membraae Filter Method for Evaluating Airborne Asbestos Fibers", U,S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National institute for Occupational Safety and Health, Cincinnati, Ohio 4S202 (November, 1971), 5. Leldel, N.A., S.C. layer, R.D. Zumwalde, and K.A. Busch, "USPHS/NIOSH Membrane Filter Method for Evaluating Air borne Asbestos Fibers", U.S, Dspsrtment of Hsslth, Educa tion and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Cincinnati, Ohio 41202 (June, 1977). T.ll nwypvwtv--wyy "fry CRMC-M&S 002946 r* * I. r- r L 9. Liidtl, N.A. and K.A. Butch, "Statistical Methods for the Deter mination of Noncompliance with Occupational Health Standards", MIOSH Technical PubUcation 75-159 (1975). i ?.$4 CRMC-M&S-002947 APPENDIX A: Case History of Substitution far Asbestos Products - Calcium Silic*tc Molded Insulation TI.ermobestos was Johns-Manville's tradename for its molded insulation, a calcium silicate product reinforced with arbestos and capable of Insulating up to 1200 F. Its application was widespread both in the general industry and shipboard applications as molded insulation that could be cut and fabricated in the field to fit a variety of high temperature applications. The manufacturing process involved blending the raw materials, (Ue. lime, silica ing the shapes, and autoclaving under heat and pressure which caused a hydrothermal reaction forming the hard calcium silicate product. The health hazards associated with using these products first surfaced in 1964 as a result of SelikofPs studies on insulation workers. Sub sequently, work practices were determined not to be effective to con trol the dust problems associated with field fabrication. Therefore, in mid-1960's Johns-Manville initiated research and development effort to which was intensified in 1968 to find a suitable substitute for asbestos, in calcium silicate insulation. As reported by Johns-MavUle# several process considerations bad to be taken into account when considering substitution. The raw Tle information for this case history was based on on-sltc interviews and follow-up cor respondent v with research snd develop ment personnel of Johns-Manvllle Corporation, Denver. Colorado. A. S CRMC-M&S-002948 material* mutt bo easily dispersed and maintain their fluidity until melding. The material must have the property of good filtcrability to extract the excess water before autoclaving; the product must have sufficient Independent strength to hold its form before autoclaving; and. the drying time of the product must be relatively short to con serve energy. Finally, the manufacturing process must be able to maintain a high production rate to justify the economics of the product. With respect to the properties of die finished product, the new materi- iai mast have "good shipabllity" i.e., a light weight product for lower shipping cost, resistance to breakage. For application In the field, tiie product must have abralsion resistance to withstand fabrication handling and have high transverse strength. Furthermore, from a marketing standpoint, the product must be able to perform adequately and sell competitively. Johas-Manville first attempted to remove the asbestos fiber from the product. This resulted in failure due to lack of strength. A second attempt was to keep the same manufacturing process, but try alter native fibers. These investigations included such materials as: organic fibers inorganic fibers rayon, cuthen linten polyester, flax isal, cellulose product* glass mineral wool A*t >'W'TW9i'rm"ffr"nv A\r CRMC-M&S-002949 All of these trials failed because the fibers were destroyed by alkali or thermal attack during the hydrothermal reaction in the autoclaving process. The third major research effort was to change the process to adapt to characteristics of new raw materials. In this case, a pre autoclaw process was utilised by first blending the raw materials of lime and silicates and then autoclaving to form a calcium silicate slurry. The new reinforcement fibers were subsequently added to provide strength. This approach met with success by using a combination of polyester fibers for wet strength applications and fiberglass for temp erature resistance as the reinforcing fibers. The time involved for this phase of research was approximately two years from early 1969 to late 1971 and involved approximately $250, 000 in direct labor costs. Johns-Maavills then moved into the development phase in start ing-up the actual manufacturing process for their new asbestos-free product, bow called Thermo-12, The calcium-silicate flurry was found to be extremely abraisive and destroyed the original piping in the pro cess, Therefore, a complete re-design of pijfiffl^and valving was re quired. Additionally, the process for Thermo*12 required higher temperatures and pressures than those for Thermobestos, so that pressure vessels had to be modified. There was a problem involving quality control of raw materials due to the sensitivity of the process and the fluctuations in material quality, ,it also has been determined A.S vr CRMC-M&S-002950 7r~~7 V. .I' that the maintenance costs for this new process has increased approxi- matcly 10% because of the corrosiveness of the intermediate materials. L The initial start-up of the new product line was in July 1972 with modi r fications and ro-design continuing through 1973. Johns-Manvilie provided CONSAD with research and development i: costs for converting Thermobestoa to Thermo-12 as follows: r Approximate Costs Associated with Conversion from Thermobestos to Thermo-12* Capital Expenditures Start-lip, overruns, production losses Lois of profits on sales Technical and engineering personnel expenses Research Costs Total $ 5,800,000 6,100,000 3,100,000 350,000 I774600 $17,124,600*** A review of the Thermobestos/Thermo-12 sales as reported by Johns-Manville is presented as follows: 1970 1971 1972 1973 1974 1975 1976 $ 7,500,000 9.650.000 11.240.000 7.258.000 11.545.000 13.670.000 20,000,000 Year of Conversion Production capacity doubled. Total Industry sales were approximately $45 million in 1976, *Cost figures cover the period 1973-1976, which is essentially the span of conversion. **Rosearch costs span the period 1969-1976, **The above figures do not include corporate-division taskforce expenses, nor management time* A.4 f' CRMC-M&S-002951 * Price Increase during this period were lathe 5-7';i range* No signi ficant price increases were instituted by Jolms-Manville or its competi tors (Owens-Corning, Flberboard Corporation) as a result of new product formulations* For competitive reasons, no attempt was made to recoup any significant portion of these conversion costs* As is evident from the above discussion of research process changer and costs, the effort to replace asbestos in this application was both difficult and costly* This example has bean cited to illustrate some of the complexities Involved in replacing asbestos in various product applications* Even though much experience was gained through this experience by the manufacturer, it is not necessarily transferable to other product applications* It may be fair to say that research and development efforts to find substitute for asbestos will be as unioue as the individual production and product/performance requirements. : ic ! f A.S CRMC-M&S-002952 * *4 I I -t <i\'' :!& APPENDIX B: Materials Evaluated a* Potential Asbestos Substitutes This appendix la arranged in tabular form to present materials n evaluated as potential substitutes for asbestos a? identified In the liter ature and through conversations with industry sources. For each c material la listed the product applications where research has been r undertaken toevaluate Its substitution potential. Information is given 4. comparing the cost of the material to asbestos used in that specific product application. Additionally* general performance characteristics L and pertinent comments for these materials is briefly outlined for each application. This listing is in on way Intended to be comprehensive to r include all research and development In the present efforts to replace asbestos. However, it should provide significant background inform ation to demonstrate sis scope of these present RAD measures. B.l CRMC-M&S-002953 ^Trvrre"* -W sr. . ...... *9 .I . ,.'l V '' . f* I I i. i ? MJJ ................" , ' hXt nsf* Ip \ . Ci I I. i: i: r m* i: c r u L r L L CRMC-M&S-00295 5 CRMC-M&S-002956 S-UK/tfc. n b M M presently u tilis e d t i b t i t s i substitute; is net Applicable to k ith tem perature applications  .t i C i j, },ii iI m1i < I?l*sf1-i * f i1 I118 1! -IIf5i -!3. i1f5-l3:; I J |i I tji 1 ll Sill i: 11 i1 fjtl ir$t i l? 1i if; sJsil.lI. r i: 1: I* l 5 1 i? H ill ! II mi 11 l! Mi i H M'S u11* g 2 i* l2 l1 3H*7i L*3* 3JIf:Sjs211Sc1123 fi1A i5iijSflvl2S*s*l*| 3|?f l| is fJis* -fiSi3-ilt-*ii-!:2 5: 1? J=-2S; jJIm::isiia tI>f 1t1| 5SS|1|*ij3rtsj3i5f-I5s u L i Hft. < r^s.11l; <iJSi t1ii iS*- 1S^J*Swf*. :I^i*i. i h |S j1J # l s fa 111| ljl,,| i!j] ]i . Ji . if III? !l||*l 1 If <' L 14n1* n ,* is 11 fS ai . r CRMC-M&S-002957  %egm*%e* Nx** s^ i: 1 *Ng* Wx S--? . I 20X* .1 If s-SI!; s;i!-is3;i: .*i t\| H ii-l |i 1 r| g * X S# 5g ,I.i*;s'!!}: 1?]! 1 IliJ jl | : i |l Isli :! i I if IJSI i | ::Hi If U i 45 |I 3l`s i| !] | >'ilh .113:1 ji If !Jil 1J li i mil 51 S3 11 s". - i 12 | t i !l Is !j li if;ii li 11 il |] |ji;i i; si si *1 lijll I? |l ?? lili; Iji-I iiHl u i 10s 1: H 111 i!?Ii H is 1! til IIIs| Vs it H l\m Hill 8? ill ti |l ji it?:? to * li all Hill it I? U Jills A *. !i 1* l:2i ^ 5T. * S ti1l2 |J'*I= 28 11, 1 h, ii l.'iS *Sm if i4ii < !* v.l l1i-1s rlI**is.* Ul j!f*Jjf *< *iJ=1w^T0 fs: li- |I::n I il s | u* i 1 1 ! i ll slfill i r | hhui e> < *Is111i a. 5s;* 1 I1-1lo1 1 J*ftJtosC I'm* !2m*1msa i 3 ( 5 < n.c CRMC-M&S-002958 ' ot%* * -- 2fr S 5 c s* *5 5* f2. 5 f Je f x Jg-| 1 * | j| | T* J . * ifii: 1: i |I !i| i: 1 lisp i? s. 2i. fS*L*Ts*JS J1? 05 5 -5 ! 11 sis-- g pl|i i 1 I3"la !? * . 8\s S| i' |S S|s 1 11 1|S 1 1 i-S" "1 S *= 1 * |t e-5 !* Se 2 3? 2-gle ~s SaS- 2^S s 25--15 S 5.5:; i: 1 ft i il!* |ls i l; is;! i u 10 ; i 22ff| Z Il 1 2 2iIf*sis iJs2L2'oeSICS2*.Sj l.-s:2:ia^a s~8s Z i SjSS* gSf * M * : 2 5*:^ ; = i? Ililil- i?i 1: Si 14 f^i *Js - ial. *%2 <3s5*s*Ji|?-24;5 * * 1 ' I 's -- -- *.2-s s ;H ?- a -; r: 1 1 li Siifll Ilf 11 111 Hit It1 f f 1, 1= i*TA\ it?*t. f * *H <. ' i Ws Sd tt-s *3f. J-2 50 * ,cf?|i!. 1]iV! ff=*S I4 ** |01 . 0| p2s -- n < -- Sn -- , I 1 0 . * * | z | z mS 5 .J-sf jsti# 1li1< If If 12 it 10 V -| i Is 51 1 I II i J1jl 1 sf ii *f_ i 1 bni till 1 ^2 i ii i 1 li s r..? CRMC-M&S-002959  i. P fle t CMnp*r*4 REFERENCES FOR APPENDIX (B) 1. Jenea, Horbrt L.. "Structural Behavior of Polymer - Based EClass Fiber Reinforced Concrete When Exposed to High Temperature, Incindiary Conditions, " Society of Plastics Engineers, Ann-t Trcfc Conf. 32nd, 20, San Francisco, Calif., May 13-16, 1974, p. 436-439. 2. Unpublished data provided by Johns-Manville Corporation, Denver, Colorado. I. Conversation with General Electric Corporation, Pittsfield, Mass., April 29, 1977. t 4. Conversation with Plastics Engineering Company, Shebogan, Wise., April 26. 1977. 5. Conversation with Industrial Products Company, RaybestosManhattan Corporation, North Charleston, S.C., April 4, 1977. 6. Unpublished data provided by Friction Materials Product Company, Rayfeestos-Manhattaii Corporation. ?. Conversation with Retinoid Corporation, St. Louis, Mo., April 26, 1977. 8. Lankard, David R., 'Tiber Reinforced Cement-Based Composites," Am Ccrzm Soc Bull. v 54, a 3, March 1975, p. 272-276. 9. Conversation with Hoppers Corporation. Pittsburgh, Pennsylvania, April 18. 1977. ; 10. Krenchsl, Herbert, "Can Asbestos Be Completely Replaced One Day? " Risem Symp: Fibre Rcinf Cem and Cone. September 14-17, 1975. p. 335-346. 11- Plastic World, Knsstbsr 19, 5973, p. 62-65. 12. Unpublished data provided by Dupont, Wilmington, Delaware, April 14, 1977. 13. Wood, Staart A., "Fllltrs Are Carrying a Heavier Load These Days", Modern Plastics. vS2, n6, June 1975, p. 42-44. CRMC-M&S-002961 14. Hawley. George C., "If/.R MICA - New Muscle for Plastic", Plaster V.'orld. v34. a4. April 19. 1976. p. 36-39. 15. "Reinforced Plastics in Chemical Plant", British Plastics. v43. a9 September 1970, p. 105. 16. Conversation with H. K. Porter, Pittsburgh, PA April 18, 1977 17. Conversation with Friction Materials Standard Institute, Paramuo, New Jersey, March 4, 1977. 18. Conversation with Sepco Corporation, Birmingham, Alabama, April 22, 1977. 19. Sioha, U. N., et. al., "Possibilities of Replacing Asbestos in Asbestos Cement Sheets by Cellulose Pulp", Indian Coeer J., v. 49, a. 8 August 1975, p. 228-232, 237. 20. Conversation with Monsanto Corporation, Akron, Ohio, April 5, 1977. 21. Mach, L., "Mineral Asbestos Substitute", Paper # ID/WG 44/M presented at United Nations Industrial Development Organization, October 17, 1969, 22. European Chemical Nows. April 26, 1974, p. 32. 23. Conversation with General Electric Corporation, Pittsfield. Massachusetts, May 2, 1977. 24. Asbestos Dust in the Conruction Industry - Technological Feasibility and Inflationary Impact Analysis, Research Triangle Institute report to Occupational Safety and Health Administration, March 21, 1977. (Draft) 25. Conversation with 3-M Corporation, St. Paul, Minnesota, March 9, 1977. 26. Pontik, Robert E., 'Special Curtain Material Reduces Energy Required for Furnace Applications", Ind Heat, y, 43, a. 4, April 1976. p. 26-31. CRMOM&S-O02962 27. Slice, Seong K., "Ceramics in Automatize Brake Materials", Am Czrnm Sc Pull. v55, n6, June 1976, p. 285-233. 28. Product Brochures from Babcock If Wilcox Inc.. Augusta. Ca. 29. Filtration, December 1976, p. 614-620. SO. Chemical Engineering, June 24, 1974, p. 116, 119. SI* Product Brochures on "Kevlar" Dupont, Wilmington, Delaware. 32. Chcmtsche. September 1974, p. 607. S3. Shivers.' J. C., **New High Temperature Fiber", Text Ree J. v44, n9, September 1974, p. 665-669. 34. Nelson, H. M,, "Crash Survival, Help From die Track", Automotive Industries. vl41, n? October 1, 1969, p. 57-63. 35. Product Brochure, "Nomex", DuPont, Wilmington, Delaware. 36. Hentscb-sl, Robert A., "Nomex Aramid Papers - Properties and Uses". TAPPI Pan Synth Conf. Pittsburgh, Pennsylvania October 6-8, 1975. p. 189-213. 37. Rubber World. July 1974, p. 33-34. Palmayra, New York, April 20, 1977 38. Conversation with Garlock Corporation, Pataayra* N.Y, April 20, 1977, 39. Conversation with Dupont. Wilmington, Delaware. April 21, 1977. 40. Veghte, James H., et.ai., "Evaluation of Fire Retardent Fabrics". Aerospace Medical Research Lab Wright-Pattcrson AFB, Ohio, AMRLTR-72-66. November 1972. 41. Staton, Robert M. Heat Transfer and Flammability gf Fibrous wiiiefiiU, Air Force MatorialsXab, V. nght-Patterson AJt'fi, &tuo, AFML-TR-70-238, February 1971. 42. Conversations with Owens-Corning Corporation. Toledo, OH. May 6, 1977, 43. Hays, Allen and Creg Bergarea", Control-VaSue Packing Success Depends on Proper Materials, Design and Application", Power. vll9, 9, September 1975, p. 101-103. e CRMC-M&S-002963 mum mm APPENDIX C: Ckie Study of Potassium Titanate Fiber* as a Substitute fur Asbestos* Dupont developed a potassium titanate fiber in 1966 to be used primarily as premium pigment for high brightness paper. In 1972 Dupont introduced this material as "FYBEX", an inorganic reinforcing titanate which was attractive for their reinforcement potential and their resist* ance to alkali attack. The primary use was intended to be in reinforcing plasticls, aod in some cases was purported to be an adequate substitute for asbestos. Other applications included premium and decorative pigments, friction materials, insulation and battery separators. The National Aeronautical and Space Administration (NASA) developed a brake composition material with FYBEX replacing asbestos and conducted studies to determine the market for such a material. Limited testing of dies# titanate by Dupont to determine their health effects had takes place prior to 1966. These tests Indicated that FYBEX should be heated like asbestos. With die concern surrounding the health hasards of asbestos In i97l and 1972 and the permissible L exposure levels for asbestos being reduced, Dupont recommended that an exposure limit of 2 Abera/cc be set for FYBEX. There was concern that FYBEX would later prove to be carcinogenic, although the necessary tests were set done. Information os FYBEX was obtalnod through correspondence with the Pigments Department, E.Z. Dupont DeNemours At Co., Inc. Wilmington. Delaware. C.l I CRMC-M&S-002964  In September 1974, Dupont announced the withdrawal of FYBEX from the market, effective in December of that year. The potential health hasards of FYBEX were obviously a major factor in this discession. However, Dupont reported that equally important was FYBEX's slow market growth and the anticipation that it would become a low volume, specialty market were conditions that also prompted the with drawal decision. Dupont customers of FYBEX with difficult substitution i problem* were phased out ifi 1975. Additionally, NASA had to discontinue its efforts to develop & commercially viable non-asbestos brake lining. As reported by Dupont, many toxicologists hold the view that any Has durable mineral fiber Is the same size range as asbestos will be found fifcrogcnic and carcinogenic. To evaluate the toxicity of substitutes for asbestos, long term inhalation tests are necessary which compare i1 animals exposed to varying concentrations of die materials. Dupont reports that these inhalation tests may take two to three years and can cost in the range of $200,000 to $500,000. Xntra-trachial tests inject materials in suspension directly into die lung area of animals. These aw shorter, lest costly tests than the inhalation studies, but are also lose reliable. There is a real concern among industry that by substituting for asbestos, they may bo trading one health hasard for another. It it is true that all fine durable fibers In the asbestos site range prove to be C.Z CRMC-M&S-002965 flbrogcnic and carcinogenic* independent of chemical composition, then the chances of finding a non-toxic substitute fiber for asbestos may be low. An excellent example of this situation is NIOSIl's recent criteria document for fibrous glass in which they recommend an exposure limit of 3 flbere/ce, 8-hour time weighted average. The toxicological data oa other possible substitutes was not part of CONSAD's charge for this study. However, there are serioud questions concerning the difference in toxicity between asbestos and possible substitutes that remain un answered. C. 3 CRMC-M&S-002966 t .f - * P rtc* Ct>ntp*r4 ~t 'f' * 1 f. ' * ' Av' CRjVfC-M&S-002968 >t CRMC-M&S-002969 2 J *5 S 4t 19t) J 2 1I s 3t* Sft it 2 o dXVt 40 = I is *! 1s" ?--s | .v. * 1 8 m" JB!. 2 *3 X J9> a5eS i* & S:aa * g>3 e S*** J2 s* a** 1*1 --3 1&tt *=u *&% js J 2 .* V9 J* sSgJ i;*?~k K Jt S' " - Ik B 2 s 1 J t t* t J P 1 3 f i -3 i 3 a* * J! u a CRMC-M&S-002970 A CRMC-M&S-002971 <* i I I :) j s pulp a rpU<amant lo r ibiai CRMC-M.&S-002973 ' , \ I* *4 r* !I 1 fe i 1 * sV i! a. I I ! ."5 s 3 I * I 3 I l I | CRMC-M&S-002974 **_ ,m CR MC- M&S-002975 l i(C i t i nIm A*r?H^t ( "I*l;' . v.ll-. ;c-. : T ..t. "a .: .oatsr t2vtu 14 , tVt'i 'i t i!a (h lav H H ittry iwr p lp t.) * * ! COK1AO t lm it a s to sad <m canvarsatlooa w ith A R M C O S te a l C a r p ., C orf. Angela* W iu r and P a a ir Company, k litk Bay M oalctpat U tU lty D is tric t, T r*a * T *a Supply, and U N lU fcLL.