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FILE NAME: Garlock (GAR) DATE: 1982 Dec DOC#: GAR043 DOCUMENT DESCRIPTION: EPA Report - Analysis of Fiber Release from Certain Asbestos Products \ AUTHENTICATION I. Linda A. Travers, certify that I am the Director of the Information Management Division of the U.S. Environmental Protection Agency's Office of Toxic Substances and that the attached document is a true, correct and compared copy of a document in my official custody, consisting of: I A draft Final Report prepared by the GCA Corporation (GCA-TR-82-53-G) entitled "ANALYSIS OF FIBER RELEASE FROM CERTAIN ASBESTOS PRODUCTS" dated December 1982, and contained in the docket for the EPA "Asbestos Ban and Phaseout Proposed Rule," docket No. OPTS 62036, consisting of 160 pages in all (pages 150 and 155 are missing). Subscribed under penalty of perjury on Sj l%_____ __, 19?f. f / fr X iK ' (X Linda A. Travers, Director ! Information Management Division (TS-793) Cer tification I. Gerald H. Yamada, certify that I am the Acting General Counsel of the U.S. Environmental Protection Agency, that I have duties throughout the United States and that the official whose signature appears above has legal custody pursuant to 40 C.F.R. 2.406 of the original document of which a copy is attached, as witnessed by my signature and the official seal of the Environmental Protection Agency which appear below. < I U.S. Environment*! Protection Agency Office of Pesticides and Toxic Substances Chemical Control^Division Washington, D.C, Contract No. 68-01-5960 Technical Directive No. 15 /D ^ ' <3 O / EPA Project Officer James P. Bulman j ANALYSIS OF FIBER RELEASE FROM i CERTAIN ASBESTOS PRODUCTS I Draft Final Report ' trr) a > f /3S- 3 December 1982 Prepared by Peter H. Anderson Marc A. Grant Robert G. Mclnnea William J. Farino l. - I I I CCA CORPORATION GCA/TECHNOLOGY DIVISION Bedford, Massachusetts DISCLAIMER Thi Draft Final Report vaa furnished to the Environmental Protection Agency by the GCA Corporation, GCA/Technology Division, Bedford, Massachusetts 01730, in fulfillment of Contract No. 68-01-5960, Technical Directive No. 15. The opinions, findings, and conclusions expressed are those of the authors and not necessarily those of the Environmental Protection Agency or the cooperating agencies. Mention of company or product names is not to be considered as an endorsement by the Environmental Protection Agency. ii r CONTENTS Figures Tables ! Introduction......................... 1 Overviev/purpose. ............................. I Report organization .......... . ^ \ Qualification of analytical techniques and airborne fiber monitoring data . . . . . . . . . . . . . . . . . . 3 References. . . . . .......... . . . . . . . . .......... 5 2. Asbestos-Cement Sheet Products ................. . . .......... 6 Introduction. .................................... . . . . . 6 Secondary processing-- fabrication ................. . . . . 9 End use activities............ 11 Airborne fiber monitoring data. . . . .............. . . . 15 Summary of f i n d i n g s ................ 17 References...................... 20 3. Flooring Products. . . . . . . . . . . . . . . . ............... 22 Introduction.......... 22 Secondary processing-- fabrication ................ 23 End use activities.......................................... 23 Airborne fiber monitomg d a t a ............................. 26 Summary of findings ..................... 30 References. . . . . . . . . . . . . ....................... 33 A. Coatings and Sealants.............. 36 Introduction................................................ 36 Secondary processing-- fabrication . . . . . . . . . . . . . 3S End use activities....................... .................. Airborne fiber monitoring data.............. 4L Summary of f i n d i n g s ........................................ 41 References. ..................... 47 5. Textiles ............................... 48 Introduction...................... 48 Secondary processing-- fabrication . . . . . . . . . . . . . 49 End use activities. . . . . . . . . . . . . . ............. 53 Airborne fiber monitoring data. . . .................. . . 57 Summary of findings .............. _ 59 References. . . . . . ..................... . . . . . . . . 67 6. ' Gaskets and Packings . ................. . . . . . . . . . . . . 69 Introduction........................................... 69 Secondary processing-- fabrication . ..................... 70 End use activities. ........................................ 71 iix CONTENTS (continued) Airborne fiber monitoring data.. . . ....................... 74 Summary of findings . .................. 79 References.............................................. . 83 7. Asbestos Paper P r o d u c t s ................ 85 Overview . . . . . ............. . . . . . . ............. 85 Roofing felt ............................................... 85 Flooring f e l t .......... 96 Millboard and rollboard . . . . . ......................... 99 Beater-add g a s k e t s ............. ................. .. 106 Electrical insulating paper ................................ 110 R e f e r e n c e s ................................................ 117 8. Conclusion and Recommendations .................................. 121 Conclusion ...................................... 121 Recommendations for future product testing ............... 144 R e f e r e n c e s ................................................... 153 FIGURE Number 1 Page Flowsheet for asbestos textile manufacturing................... 51 IV \ * TABLES Number page 1 Asbestos-Containing Product Categories Profiled................. 2 2 Partial Listing of the Many Applications of Transite A/C Sheet . 8 3 Fiber Concentrations Associated with Asbestos-Cement Sheet Product End Use Activities . . . . . .......... . . . . . . . 16 4 Airborne Monitoring Results From Using a Circular Saw and Drill on Flat A/C Sheet................................... 18 5 Summary of A/C Sheet Products Secondary Processing and End Use Activities ...................................... 19 6 Fiber Release From Vinyl-Asbeatos Floor Tile Installation, Use, Maintenance, and Removal . . . . ........... . . . . . . . . . 27 7 Fiber Concentrations Associated With the Installation and Removal of Sheet Vinyl Flooring Backed With Asbestos Flooring Felt.......................................... . i . . 28 8 Summary of Asbestos Flooring Products Secondary Processing and End Use Activities . . . . . . . . ........................... 31 9 Asbestos-Containing Coatings and Sealants................. 37 10 Fiber Concentrations Associated With the Spray Application of Asbestos-Containing Petroleum-Based Coating Products ........ 42 11 Summary of Airborne Fiber Concentrations Encountered in the Dryvall Taping Process . . . . . . . . . . . . . . . ........ 44 12 Summary of Coatings and Sealants Secondary Processing and End Use Activities ........ 46 13 Asbestos-Containing Textiles and Their End Use Applications. *. . 50 14 Airborne Fiber Concentrations Resulting From the Use of Asbestos-Containing Cloves .................................... 60 v TABLES (continued) Number 15 16 17 18 19 20 21 22 23 24 25 26 27 Page Summary of Asbestos Textile Products Secondary Processing and End Use Activities .......... . . . . . . . . . . . . . . . . 62 Fiber Concentrations Associated With Various Compressed Asbestos Sheet Gasket Handling Activities .......... . . . . . . . . . 75 Summary of Compressed Sheet Gasket Secondary Processing and End Use A c t i v i t i e s ................... ................ .. 80 Summary of Packing Secondary Processing and End Use Activities . 82 Fiber Monitoring Data from Asbestos Roofing Felt Studies . . . . 89 Summary of Asbestos Roofing Felt Secondary Processing and End Use A c t i v i t i e s ................. . . ............ .. 95 Summary of Flooring Felt Secondary Processing and End Use Activities . . . . . . . . ................... . . . . . . . . 98 Industrial, Commercial and Residential Uses of AsbestosContaining Millboard and Specific Applications . ............ 100 Summary of Millboard and Rollboard Secondary Processing and End Use A c t i v i t i e s ................... ............ .. 107 Summary of Beater-Add Gasket Secondary Processing and End Use A c t i v i t i e s ................................................ Ill Airborne F.iber Concentrations Resulting from Asbestos Electrical Insulating Paper and Board Fabrication and Installation Processes ........ . . . . . . . . ........ . . 114 Summary of Electrical Insulating Paper Secondary Processing and End Use A c t i v i t i e s ................... ................ .. 116 Measured Airborne Fiber Concentrations Resulting from Secondary Processing and End Use Product Testing 28 Numerical Summary of Monitoring Studies Performed on Asbestos-Containing Products ............. . ................... 161 29 ' Asbestos-Containing Products and Activities of Concern Recommended for Initial Fiber Monitoring Study .......... . 145 s vr >* * SECTION 1 INTRODUCTION OVERVIEW/PURPOSE Over recent years, much has been written about the consequences of exposure to asbestos fibers during the manufacture and handling of asbestos-containing products. Governmental regulatory agencies such as the Occupational Safety and Health Administration (OSHA), Consumer Product Safety Commission (CPSC), and United States Environmental Protection Agency (EPA) have been entrusted with the responsibility of protecting workers, consumers, and the environment from exposure to asbestos fibers. It is estimated that asbestos fibers have been used to manufacture 2,000 to 3,000 discrete commercial and industrial p r o d u c t s . A s b e s t o s fibers may be released to the ambient air during product manufacturing, secondary processing, and end use. Persons may be exposed to asbestos fibers during the performance of these activities. This study was undertaken to profile the activities routinely performed on asbestos-containing products during secondary processing and end use and to report, when data were available, airborne asbestos fiber concentrations associated with such activities. The data presented provide EPA with information on the likelihood of fiber release from selected asbestos products. EPA will distribute the data to other governmental regulatory agencies, OSHA and CPSC, and where the presence of risk is determined to be unacceptable, measures will be taken to reduce human exposure and environmental contamination. REPORT ORGANIZATION This report is organized by the asbestos product categories presented in Table 1. The categories profiled are asbestos-cement sheet products, flooring products, coatings and sealants, textiles, gaskets and packings, and paper products. The latter includes roofing felt, flooring felt, millboard and rollboard, beater-- add. paper, and electrical insulating paper. These categories were investigated to augment EPA's understanding of the fiber* release potential from asbestos-containing products. Other products that contain asbestos include asbestos-cement pipe, friction materials, reinforced plastics, and under paper products, pipeline wrap, commercial paper, and specialty paper. 1 TABLE 1 . ASBESTOS-CONTAINING PRODCT CATEGORIES PT.OTILED L. Asbestos-Cement Sheet Products Plat Sheet Corrugated Sheet Roofing and Siding Shingles 2. Flooring Products Vinyl-Asbestos Floor Tiles Asphalt-Aabeatoa Floor Tiles Sheet Vinyl Floor Covering (Backed with Asbestos Flooring Felt) 3. Coatings and Sealants Petroleum-Based Compounds Water Soluble Compounds 4. Textiles Fire and Heat Resistant Materials Thermal Insulatioo Electrical Insulation Gaskets and Packing? Friction Materials 3. Gaskets and Packings Compressed Sheet Gaskets Mechanical Packings (Asbestos Yarn) 6. Paper Products Roofing Felt Flooring Felt Millboard and Rollboard Beater-Add Gasket Paper Electrical Insulating Paper 2 The information presented in this report was compiled from an extensive survey of publicly available data and telephone interviews with manufacturers, secondary processors, distributors, and end users of asbestos-containing products. A computerized literature search of eleven (11) data bases revealed that the amount and diversity of asbestos fiber monitoring data publicly available is limited. Various product-testing laboratories have monitored airborne fiber concentrations during simulated product use activities, but due to the preliminary nature of their findings or to proprietary agreements they are not willing to disclose publicly the results of their studies. The product profiles presented herein include a brief description of product manufacturing operations and a more in-depth discussion of secondary processing and end use activities. Airborne fiber monitoring data are presented when available and fiber releasability is discussed. Secondary processing and end use activities include product fabrication and installation, in-aervice use, and removal, respectively. Due to the versatility of some products and the intermediate uses of others, there will be some overlap of products between categories. The overlap will be noted in the sections but not repeated. QUALIFICATION OF ANALYTICAL TECHNIQUES AND AIRBORNE FIBER MONITORING DATA Asbestos fiber concentrations presented in this report are based on the results of four different microscopic analytical techniques. The four techniques are phase contrsst microscopy (PCM), polarized light microscopy (PLM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). PCM and PLM are optical microscopic analytical procedures. PCM, SEM, and TEM are commonly used to analyze air samples, whereas PLM is generally used Co analyze bulk samples. Phase contrast microscopy is an analytical technique for quantitative determination of airborne fibers. It is presently the recommended method of Che National Institute for Occupational Safety and Health (NIOSH) for determining compliance with asbestos occupational exposure standards.^ Fibers counted are those that are ^_5 microns (um) in length and have a Length-to-diameter aspect ratio of 3-to-l or greater.^ The principal disadvantages of PCM are that the technique cannot be used to differentiate asbestos fibers from nonasbestos fibers and it has a nominal magnification of 400 to 450X^ with an image resolution of only 200 nm.^ Polarized light microscopy is generally used to identify and quantify asbestos in bulk samples of material. The technique takes advantage of specific optical properties each asbeatiform mineral exhibits. With respect to analysis of air samples, PLM may be performed subsequent to PCM analysis to distinguish asbestos fibers from nonasbestos fibers, resulting in an actual asbestos fiber concentration measurement. * Scanning and transmission electron microscopes provide greater magnification (up to 100,000X and 250.000X, respectively) and image resolution (down to 20 nm and 0.4 nm, respectively) than optical microscopes.^ Total fiber counts by electron microscopy (^25,000X) can exceed 100 times the number counted by optical microscopy (4Q0X).^ SEM used in conjunction with an 3 Itccroo baa* mlcrcchsrnical ulri fniviO* fnI(|uBtlttlv< elemental iMlyti* of the fiberl) e^irseb#'ervetCo.**' TEX with elected re electron diffriction (SAED) Howe qualitative Identic lotion of fibrous minerals based on differences a wcirtyhstaalnliEnOeXR stsrpuecctturroem.eteTrr. a4 nsmission electron microscopes can also be equipped Discretion should be employed when interpreting and comparing the fiber concentration data presented in this report. Care should be taken not to compare optical microscopy results directly with SEM or TEH analyses. In addition, one should not mistakenly compare peak concentrations occurring during the performance of an activity with time weighted average (TWA) concentrations that have been scaled over an 8 hour period. To the extent possible, analytical methodologies are identified whenever fiber monitoring data are presented. Finally, some of the data presented may be out of date. Implementation of new control measures, changes in processing methods, and product reformulations should result in fiber concentrations lower than some of those reported. In all cases, the moat recent airborne fiber concentration data are presented. 4 INTRODUCTION REFERENCES 1. Federal Register, October'17, 1979, Comnercial and Industrial Use of Asbestos Fibers; Advance Notice of Proposed Rulemaking. Vol. 4A, No. 202. 2. U.S. Code of Federal Regulations, Title 29, Part 1910.1001. U.S. Department of Labor, Occupational Safety and Health Administration, Occupational Safety and Health Standards. 3. National Institute for Occupational Safety and Health: Asbestos Fibers in Air - Analytical Method. (March 1976). pp. 239-1 to 239-20, unpublished. A. McCrone, W. C . , and J. G. Delly. 1973. The Particle Atlas, Edition Two. Volume I. Principles and Techniques. Ann Arbor Science Publishers Inc., Ann Arbor, MI. 5. Rohl, A. N. et al. Exposure to Asbestos in the Use of Consumer Spackling, Patching, and Taping Compounds. Science, Vol. 189. August 1975. pp. 551-553. 6. Rubin, I. B. and C. J. Kaggiore. Elemental Analysis of Asbestos Fibers by Means of Electron Probe Techniques. Envir. Health Persp. 9:81-94. 1974. 7. Ferrell, R. E. et al. Evaluation of an SEM-EDS Method for Identification of Chrysotile. Scanning Electron Microscopy/1975 (Part II), Proceedings of che Workshop on Scanning Electron Microscopy and the Law, IIT Research Institute, Chicago, IL. April 1975. 3 SECTION 2 ASBESTOS-CEMENT SHEET PRODUCTS INTRODUCTION Asbestos-cement (A/C) sheet refers to flat or corrugated cement board products that are primarily used in the construction, electrical insulation, glass, and metallurgical industries. Products vithia this category include flat sheets, corrugated sheets, and roofing and siding shingles. Shingles are cut from textured flat sheet and are usually painted, but also may be integrally colored. Asbestos fibers are incorporated into these products to provide strength, stiffness, and resistance to heat, rot, weathering, and attack by corrosive chemicals. Specific formulations for A/C sheet products are dependent upon the method of curing used (ambient or autoclave) and end use specifications. If the sheet product is cured under ambient conditions (moist environment over several weeks), representative material formulations are 15 to 40 percent asbestos, with the majority of the balance consisting of c e m e n t . F o r autoclave cured products, silica is added to speed the dehydration process. A general formulation for A/C sheet products cured by this method is asbestos (15 to 40 percent), cement (40 to 50 percent), and silica (30 to 40 percent).^ In addition, other fillers, binders, and pigments may be added as necessary.^ A/C sheet products are manufactured by either a dry or wet process.^ The dry process involves preparing a dry mixture of asbestos, cement, and silica (for autoclave cure). This mixture is metered onto a moving wet conveyor belt, then passes under steel rollers, is rewetted, and subsequently fully compressed under rolls. The sheet is then cut to uniform lengths and cured. After curing, the sheets are cut and trimmed to sizes ranging from the standard 1.2 x 2.4 meter ( 4 x 8 feet) size to Che smaller size shingles. Flat siding shingles are manufactured in sizes ranging from 0.3 x 0.6 meters (12 x 24 inches) to 0.64 x 0.81 meters (25 x 32 inches). Roofing shingles are produced in surface dimensions ranging from 0.23 x 0.41 meters (9 x 16 inches) to 0.36 x 0.76 meters (14 x 30 inches). Thickness of the sheet products ranges from 0.32 to 10 cm (1/8 to 4 inches).^ Wet processing is the primary method used to produce both flat sheet and corrugated sheet. The predominant wet process, wet-mechanical, involves making a wet slurry of asbestos, cement, and silica (for autoclave cure) in a vac. The slurry is picked up by a screen cylinder mold and transferred to a felt conveyor belt. After dewatering by a vacuum the material is passed to a 6 jr1 which wind layer Co Che desired thickness. WidCh o: Che sheet 13 decerniioed by che width of che vac; che length of the sheet is determined by the diameter of the accumulator mandrel. A cut is then made "cross the width of che sheet, and it is manually peeled off the rotating raarlrel onto a cransfer roll conveyor. The sheet may be partially dried by passing it over heaters before it is processed through embossing rollers and then trimming and cutting wheels. Corrugating is also done at this time, prior to c u r i n g . ^5 Another wet process involves making a slurry of ingredients as described above, and discharging it into a mold with a screen on the bottom through which water can pass. As the mold is closed, water is squeezed out of the slurry. Finally, when the sheet has the required density, it is ejected from the mold and is ready for curing.^ Primary manufacturers of A/C sheet may sell their products unfabricated directly to secondary processors or construction outfits or they may perform limited fabricating steps themselves before shipping the sheet as "complete" products ready for installation.^^ Fabricating activities performed by primary A/C sheet manufacturers are uncomplicated, large volume, repetitive operations. For example, pilot holes placed in roofing and siding shingles will normally be punched by the primary manufacturer.^ The punch presses used to form the holes are integrated into the primary manufacturing process such that they are considered part of the production operation, not a secondary step.^^ Straight edge, dimensional sawing for large job orders is another fabricating operation performed by the primary manufacturer.^ Uses of A/C Sheet Product Flat A/C sheet products are used in commercial, industrial, and residential applications. They are widely used by the construction industry in the following applications: soffit material (covering the underside of structural components), industrial partitions, fire-resistant walls, and interior and exterior decorative paneling. Sheet density, i.e., weight, generally determines a product's end use. Table 2 presents a partial listing of the many applications of one of the most commonly used flat A/C sheet products, Transite, a product manufactured by the Johns"Manville Corporation. Flat sheets, impregnated with asphalt, are used as mounting panels for electrical switchboards, bus-bar supports and controller plates, and as insulating spacers in a wide variety of electrical apparatus. Corrugated A/C sheets are used primarily in industrial and agricultural applications, serving as siding and roofing for factories, warehouses, and agricultural buildings. They are also used as linings for waterways, pilings for canal bulkheads, and as end paneling for cooling towers.^ Flat sheet is also textured and cut for exterior use as siding and aroofing wide shingles. These shingles range of styles and colors . are ^ extremely durable, and are available in 7 Abactui fa Animal h o s p i t a l * Air *hft* Air conditioning (homing) Aerator* (homing) Air p u r ific a tio n equipment Animal t i l l * Architectural panel* Arc b a r r i e r * Baffle* B o i l e r room* Bakery mixing (ten d * Bakins oven* Bulkhead* Blover duct* B aaeball dugout Boctom p la t e * (fo u n d rie a ) Burial vault* Call coapartment a ( e l e c t r i c a l ) Cell door* ( e le c tr ic a l) Cemetery aarker* Incinerator* Canopic* Cooling cover* Chute* Conveyor apron* Conduit* . D en ta l i*fg. work t a b l e * Dry k i l n * Orying cover* Du*t c o ll e c t o r * rafting table* Draft d eflector* Drying oven* Duct* Elevator lining* Exhauat v e n t* and d u c t* Fiat ia Factory in te rio r/e x te rio r panel* Far* building* Floor underlayment Fune hood l i n * r * / d u c t * Fumigation chamber* Freezer locker* Feed bin* Flume* F u m a c* room* Fire barrier* Fouedrie* Flour m ill* Freight bouae* F ir* lookout* Fire (Cation* Freezer tunnel* Fuel hopper* Foundry box* Fireplace acreea* Crain bin* Crain alavatora Craenhouae* Manger* Heat a h ia ld t Mothouaei Hopp a r i Hood * ( a c o v * . v e n t i l a t i n g ) Incubator* Welding tab le topa lannel* Kick p lat** Laboratoria* Lining! for tanka Louver* Nachia* thed* Milk hou*et Hater board* Mink v arr ana Machine guerd* Outdoor f u r n i t u r e ( t a b l e * , benche a) Fanela, partition* Fizz* oven* Portable pray chut** Poultry houata Protective covering for n a rin ite oven* Prea* platen* Prea* plat* P a lle t* Playhou*** lad ia tor cover* Refrigcracor* ladiant panel* Sandbl**:ed paoel* Spray paint booth* Smoke houae* Sepcic tank* Slu ic* boxai Spacar* Storage bin* Scova ihield Suocere* Spaghetti dryer* Swing* Sand boxe t T ibie topa Tank cover* Toilet parcition* Tank* ( a ix in g /it o r a g e ) Vaulta V*e* (a x te rio r) Vainaeotiag Water tank acreena Water creatlng equipoenc Walk-in eoolera Walding t a b i * top 8 forr. unfinished material Into a functional product ready for end use. As indicated above unapecLaiired material fabrication may be performed by the primary manufacturer. Asbestos-cement products requiring more specialised fabrication are usually handled by secondary processors, known as distributors, job shoppers, or cutters, who are located throughout the country. Secondary processing by job shoppers ranges from minor alteration of the sheet product to extensive fabricating operations involving sawing, drilling, sanding, routing, or beveling. Such operations, for example, are performed during the fabrication of A/C sheet to be used as laboratory table tops or mounting panels for electrical switches. In both cases, the A/C sheet must be finished Co facilitate the insertion and attachment of plumbing or electrical components. The most common fabricating operations performed by secondary processors are sawing and drilling, with sawing predominating. Operations such as sanding, routing or beveling occur less frequently. Overall duration of these activities varies, ranging from close to 8 hours per day at a large volume job shop using seraiautomated equipment to 2 to 4 hours or less per day at smaller shops. The actual sawing of a 1.2 x 2.4 meter board, however, lasts only a few seconds. The same applies to drilling operations. Routing, sanding, and beveling operations tend to last longer but are not performed as often. Accumulated over an 8-hour workday the total time associated with actual performance of dust generating operations adds up to several minutes (est. 5 to 30). In general, A/C sheet products used in interior applications require more extensive fabrication than board products used" for exterior applications. Based on the chemical composition and physical structure of A/C sheet, asbestos fiber release is not expected during product handling except when the macerial is physically altered by mechanical disruption. A/C sheet is a hard, dense building product. The high percentage (>_40X) of cement in the product produces a tightly bound matrix that is difficult to break apart. Only when an energy intensive abrasive force is applied to the material, such as sawing or drilling with a power tool, is a fine dust generated. The cutting energy supplied by the power tool pulverizes the asbestos-cement matrix, disintegrating the material to the point where it is easily entrained by the high speed rotating blade or bit. Because substantial dusting can occur during the fabrication of A/C sheet using power equipment, engineering control measures are usually implemented to minimize asbestos fiber release. The tools used to fabricate A/C sheet products are similar to those used by the metal, masonry, and woodworking industries. These tools are stationary, heavily constructed pieces of equipment driven by electric m o t o r s . M o s t of the time associated with their use is consumed in equipment setup and material layout and not in the actual performance of'the cutting or grinding operation. The tools most commonly used are fixed table saws, drill presses, large surface grinders, and milling (lathe) machines. Hand tools, used to fabricate smaller pieces or assist in more detailed work, include electric sanders, routers, and drills. With respect to the tool's 9 * cucclng edge, masonry bic are often used Co drill A/C sheet Log, whereas diamond ar.d carborundum blades or abrasive wheels are used with the sawing cool*. 7'1,0 A major difference existing between the tools used on A/C sheet products and those used on metal, masoary, and wood is the former's inclusion of a dust collection system. Most job shoppers use tools designed to prevent the release of fibrous dust into the workroom environment. The primary dust control system used by secondary processors is a simple dry vacuum exhaust system, with suction pickup points located as close as practicable to the site(a) of dus-c generation. This system is either of high air velocity, low air volume design such as those applied to stationary table saws and drill presses or a low air velocity, high air volume canopy hood design used for general area control. Another dust control measure commonly applied to table sawing operations is water spraying.1011 Under these conditions,'the cutting blade and point of material contact are wetted by a constant spray or flow of water. Dust-laden water is captured and passed through a series of sedimentation tanks before being recycled. Secondary processors of A/C sheet products are relatively small business concerns. Fabrication of A/C sheet is commonly performed in single story buildings. The workrooms within these buildings tend to be open with few internal walla and have high ceilings. Air circulation within the fabricating area results from infiltration through passageways and windows, with exfiltration by the dust collection vacuuming system.11,1^ No specialized filtering of the workroom air is carried out. Secondary processors tend to deal with one or two industries or end use product applications. To illustrate this point, examples of two typical secondary processing operations are given below. Laboratory Table Tops A/C sheets make stroog and chemically resistant workbench tops. A representative of the Brown-Morse Company of Muskegan Heights, MI, which deals almost exclusively in laboratory table tops and fume hood liners, referred to their fabricated materials as "complete" products, materials that do not require further processing.1^ Fabricating operations most frequently performed on these products are sawing and drilling. Final processing involves wipe cleaning the surface and edges, and painting if aesthetic qualities are desired. Fabricating tools used by Brown-Morse include a table saw with a diamond blade and a standard industrial drill press; both are manually operated. Typically, during the course of an 8-hour workday, an employee is involved in sawing sheet for 4 hours and drilling for 2 to 3 hours. Sawing one straight edge t.akes 5 to 10 seconds, while drilling takes 3 to 5 seconds, depending on thickness of the sheet and diameter of the hole. The total daily time associated with the performance of each dust-generating activity is estimated to range from less than 5 to 30 minutes. All cutting Cools are equipped with dust control devices; either water-- spraying equipment or dry vacuum hookups venting exhaust air through a fabric filter. Workers in this shop also wear dust control face masks. .10 Fabricated Sheet Produce for Che Foundry Industry The Hines Flask. Company of Cleveland, Ohio, fabricates A'- sheet products for the foundry industry.^ The company purchases Transite (core plate) from Johns-Manville and fabricates the material for use as jacket linings for "green sand" molds* Fabrication involves saving the sheets to required dimensions, drilling a specified number of pilot rivet holes, and fastening the flat boards to a metal frame, making the jacket liner. Another product fabricated by the company is pallet car tops. These tops form the base of a foundry cast upon which a mold sits during pouring and cooling prior to shakeout. Sheets are cut to specified dimensions, but are not drilled. In use, the sheets lay flat on the pallet car top. In addition to being sturdy and noncombustible, Transite boards are true and flat at every point. This accounts for their use in the manufacture of brass, aluminum, gray iron, malleable iron, and steel castings. During an 8-hour workday, board sawing accounts for approximately 4 hours of a worker's time and drilling for 2 to 3 ho u r s . ^ As with Brown-Morse, the total sawing or drilling time is estimated to range from less than 5 to 30 minutes. The majority of the time is spent in equipment setup and material layout. Actual sawing and drilling operations last only a few seconds each. Large manually operated table saws and standard industrial drill presses are used to fabricate sheeting. All tools are equipped with high air velocity, low air volume vacuum exhaust dust collection systems to minimize fiber release to the workroom air. Operators are required to wear dust protection face masks and are also provided coveralls. Fabricating equipment is cleaned at the end of each workday with a portable vacuum unit. No special workroom air ventilation is employed. Dust control equipment is activated whenever operators are present in the workplace. The sawing and drilling activities performed and the tools used by the two secondary processors described above are representative of the fabricating operations conducted on the A/C sheet products covered in this section. The tools and control measures employed are essentially the same whether electrical insulating boards or interior/exterior wall panels are being fabricated. The duration of the activities will vary, however, depending on the extent of product finishing required. END USE ACTIVITIES Field fabrication of A/C sheet products, which may be required prior to installation, is infrequently performed. Approximately 95 to 98 percent of the dust generating operations conducted are performed by the primary manufacturer or secondary processor before Che product is sold to the end user. * ^ The term "complete" product is often used to describe the item sold to the end user. It is apparent that a concerted effort is being made by Che manufacturers of A/C sheet products to minimize field fabrication. However, when field fabrication is required, the extent of fabricating and the tools used vary greatly. 11 r T*"V T H U .. ""T I 111" i r-T ~TTr~rrTi~'TTTT'/n'll Mill III-- i n IIP n i l There exists an inconsistent approach by construction firej to provide adequate worker protection during field fabrication. This issue is compounded by the fact that the construction business is very competitive; awarding of a contract is directly related to cost bids. Given this rule of survival, many contractors bid at levels that would not allow them to purchase specialized duat control equipment or implement proper work practices to minimize employee exposure. Generally, only the very large firms or specialized outfits buy tools equipped to minimize fiber release. Many medium and small-size general contractors saw, drill, and sand asbestos-containing building materials using the same tools they use on wood, brick, metal or concrete-baaed m a t e r i a l s . ^ Aa a minimum, facial dust masks may be worn by the workers. Also, onsite fabrication is normally performed outdoors whenever possible. Field fabricating tools used to prepare A/C sheet for installation range from electric saws, drills, and sanders to manually operated handsaws, hand clippers, scoring knives, and rasps. Power tools, which are more likely to be used on the thicker and denser A/C sheet products, tend to pulverize the cement matrix releasing fine dust and possibly, free-form asbestos fibers. As a consequence, power-assisted field fabrication tools equipped to capture dust generated during operation have been developed and are commercially a v a i l a b l e . ^ These tools include hand-held power saws, sanders and drills with filter bags attached directly to them or stationary (fixed) saws or drills that are shrouded with an air exhaust line extending to a portable vacuum motor mounted to the top of a metal drum. In addition, manufacturers of A/C sheet products recommend that specific work practices be implemented during product installation to control d u s t i n g . A s with most work practice guidelines, however, the recommended procedures are widely publicized but not necessarily always followed as designed or intended. Field fabrication of thinner A/C sheet products, those less than 0.64 cm (1/4 inch) thick, is typically accomplished using nonpower-assisted tools such as handsaws, hand clippers, scoring knives, and rasps. The slow cutting speed of the hand-operated tools generate coarae-size particles of asbestos-cement dust that tend to settle r a p i d l y . L o c a l exhaust systems are not normally employed when these tools are used. Ilandsawing and surface scoring are the two most widely used methods for cutting thin A/C sheet products in the field. A/C sheet cut by scoring involves placing the sheet on a flat surface (e.g., workbench or saw horses); clamping a guide bar along the cut line; and then scoring the material repeatedly after which the sheet is hand-snapped along the score line. Thia technique reportedly generates minimal dusting.^- In field fabrication'situation where a rectangular hole has to be made in the A/C sheet to allow for access to electrical or plumbing fixtures, small holes are drilled (electric tool) into the board around"the perimeter of the planned opening. The inside rectangle is then knocked out with a hammer. Any resultant rough edges are filed smooth or beveled using a metal file or rasp. The procedure just described also reportedly generates minimal dusting.1 12 K Ourins ins__t_a_l_l_a_t_i_o_n_. A/C sheet products are secured by various means depending primarily on product weight (density) and end use. The methods employed include mechanical fastening using nails, screws, or holts; gluing using epoxy or "liquid nail" adhesives; slide-in paneling using metal grooved framing; or simply laying the sheet flat under a heavy load. Installation by mechanical means or slide-in-place through metal guide channels is normally required for the denser, heavier utility and thermal insulation-type products, where che material is installed vertically.^ Gluing is more often associated with the vertical installation of light-weight, flexible-type sheets and heavy sheets installed horizontally. Examples of these latter two installation methods are: the gluing of exterior or interior architectural wall panels to vertical surfaces, and the gluing of laboratory table tops horizontally to metal or wood support c a b i n e t s . ^ Corrugated aheet is normally secured to a support structure using mechanical fasteners. Roofing and siding shingles are secured in a manner similar to chat used for asphalt-felt or wood shingles using roofing nails.^ The following presents a more detailed discussion of various A/C sheet product installations. Utility Wall Panels During installation of heavy, utility-type wall paneling, mechanical means such as fastening with nails, screws, or bolts are required to secure Che sheets Co a support surface. For most applications, whether exterior or interior, pilot holes are predrilled during secondary processing. Should field fabrication be required, standard construction sawing and drilling tools are used unless Che contractor has purchased or has access to specialized dust controlled equipment. In cases where cosmetic appearance is desired, the pilot holes are countersunk by the secondary processor. After erection, Che recessed nail or screw head is patched over with a composite hardener that may or may not contain a s b e s t o s . F o l l o w i n g drying, the patched area is sanded flush with the paneling surface. A representative of the Electro-Matic Product Company of Chicago, I L , ^ an end user of A/C sheet, stated that the majority of the electrical insulating mounting panels they purchase are processed as is, but a small number may require cutting or drilling for special applications. The contact estimated that the cutting operations would be performed once per month, lasting approximately 1 hour. Architectural Panels Architectural panels installed in both interior or exterior applications are secured using mechanical fasteners, such as bolts, screws, or nails, or an industrial strength adhesive (epoxy or "liquid nail"). Architectural paneling is flexible and fairly thin, 0.48 to 0.95 cm (3/16 to 3/8 inches) thick*. Most panels sre precut to size by a job shopper or purchased through a distributor in standard' sizes. According to a representative of Erection Specialities, Inc. of Canton, MA,} the number of panels requiring field fabrication (e.g., the cutting of panels to fit around surface obstructions or end pieces) accounts for less than 5 percent of all sheets installed. Cutting equipment r u ad In Cho r*n*e from hand held or Cable mounted power circular disc or aabrc aw Co hand op? raced saws or scoring knives. Power sews say or may noc be equipped with dusE collection exhaust'hoods. Cutting time for the paneling lasts only a few seconds. In this case field fabrication normally cakes place outdoors A/C sheet panels may also be installed using aluminum ehanelling. In this system, the panels are slid into a grooved metal framework that holds the sheets in place. Again, field fabrication may be required to get around surface obstructions, to cut end pieces, or to provide access holes for electrical and plumbing fixtures. The field fabricating tools and work practices employed are similar to those described above. The representative of Erection Specialties, Inc., of Canton, MA, 10 stated that Che company recently responded to a bid that included a clause stipulating "no field cutting of asbestos-contaiaing products." To meet this requirement, Erection Specialties proposed cutting all A/C sheet products identified in the building specifications at their main office where they are equipped to fabricate such materials safely. Another source interviewed, Lampco, Inc. of Waltham, M A , ^ a distributor of A/C sheet products, indicated that for a job requiring the installation of 1,400 to 1,500 standard size A/C architectural cladding sheets, only 15 to 20 (< 2 percent) would require field cutting. Laboratory Table Tops and Fume Hood Liners Laboratory table tops and fume hood liners are prefabricated prior to shipment to the job site. A/C sheet products commonly used for these two applications are Colorlith* and Flexboard,* respectively. During the installation of laboratory table tops, an epoxy or some other type of strong industrial glue is used to secure the tops to wooden or metal support structures. Only during retrofits or special add-ons are abrasive power tools used on the material. Performance of these activities ranges from taking the sheeting outdoors and. sawing or drilling it using tools equipped with dust controls to drilling the sheeting in place in the laboratory using uncontrolled equipment.^ The frequency of these activities is unknown- A representative of Kewankee Scientific, of Statesville, NC,^-^ a supplier of laboratory Cable tops and fume hood liners, stated that once they install the furniture according to design specifications the owner or operator of the laboratory can do whatever he wants to the furniture. Laboratory fume hood liners (Flexboard) are also prefabricated by a secondary processor to facilitate easy assembly at the job site. Once erected, the fume hood may need to be secured to the table top (commonly A/C sheet) it rests on. This process involves drilling pilot holes into metal flanges of the hood chamber and table and screwing the flange to Che bottom support. Set screws'may also be used Co secure the front edge of the hood chamber to the front lip of the table top. Installation of the set screws will not generate any dust. Manufactured by Johna-Manville Corporation. 14 r Cocru^tgd SHggC Corrugated A./C sheets are generally used as exterior wall and roof coverings, bulkhead pilings, and window overhangs in industrial and commercial structures. Corrugated sheets are installed in a manner similar to other exterior cladding products in that overlapping pieces are nailed or screwed to the underlying support surface auch as exterior grade plywood. Pilot holes are normally predrilled by a secondary processor to facilitate installation. Hoofing and Siding Shingles Roofing and siding shingles, used primarily for residential construction, reportedly last from 30 to 50 years.^ The most common method of securing shingles to a roof or building aiding underlayment is with nails. Because the material ia brittle, pilot holes are routinely predrilled or punched at the primary manufacturing plant.^ A representative of the Supradur Manufacturing Corporation of New York, NY,^ a major manufacturer of roofing and siding shingles, stated that abrasive power tools are not normally used during field fabrication. If the shingles require edge cutting to work around a surface obstruction, a specially designed guillotine cutting tool is used. Operation of the tool results in a clean edge cut, generating a minor amount of dust. This coupled with the slow cutting speed of the operation results in a low fiber release potential. Air monitoring during the performance of this activity has revealed that no measurable concentration of airborne asbestos fibers occurs near the breaching zone of the operator or in the general work area.^ For a typical installation job, only a small percentage (less chan five) of the shingles require field cutting. The service life of A/C sheet products is relatively long, on the order of several years.^*^'^ As used in the construction of buildings, A/C sheet products normally remain in place until the building is renovated or demolished. During renovation or demolition, A/C sheet products may be broken up into small pieces using a sledge hammer or other impact tools. If proper control measures (e.g. use of wetting agents) are not employed, asbestos fibers may be released into the ambient air (see following subsection). In some cases, the material may be dismantled intact and disposed of at a landfill in its nonfriable form or Che material may be salvaged. AIRBORNE FIBER MONITORING DATA Asbestos fiber monitoring studiea^- ^ covering simulated A/C sheet handling and actual field fabricating operations have been conducted. Fiber release tests on Transite have been performed in a glove box test chamber.^0 The A/C material was subjected to four routinely performed-field fabricating and installation activities. The activities were hammering, hand scoring, and sawing and drilling using power tools (uncontrolled). The test results, which -appear in Table 3 ranged from 1.1 f/cva? for scoring to 259 f/cm^ ' during sawing. The fiber concentrations recorded are not representative of the levels expected under actual field conditions. Testing was performed in a confined, nonventilated air space that likely resulted in fiber accumulation, biasing the results high. 15 c CEMENT SHEET PRODUCT END USE ACTIVITIES2 Operation Drill (power) Score Hammer^ Hammer^ Saw (power) Sampling Time (min) 1 4 1 4 l PCMb (f/cm^) 2.3 3.2 12.7 6.4 195.8 SEMC ( f /cm-*) 2.3 1.1 16.5 10.2 258.8 *Fiber* as long as or longer Chan 5 um having a lengthto-diaoeter aspect ratio of 3-to--1 or greater were counted. This applies to analysis performed by both PCM and SEM. bPhase contrast microscopy analysis. cScanning electron microscopy with energy dispersive x-ray (EDXR) analysis. ^Unclear whether this operation simulated installation with nails (fasteners). An epidemiological study conducted by Rodelsperger et al.^l showed that construction workers are exposed to fine dusts containing asbestos fibers during routine material handling activities. Monitoring of grinding operations performed on A/C sheet at approximately 40 building sites revealed that fiber concentrations (determined by PCM) ranged from 0.6 to 41 f/cm^ at Che breathing rone, with a mean of 20 f/cm^.^i Analysis by SEM showed mean values for fiber length ranging from 1 to 5 um and fiber diameter from 0.1 to 0.4 um. The ratio of fibers with a length of greater than 5 um to the total number of free fibers ranged from 4 to 60 percent, with a median value of 25 percent. The authors state that when performed, grinding accounts for only 6 percent (approximately 30 minutes) of the daily working time. Grinding is not necessarily conducted every day A/C products are handled. As such, the daily mean value, calculated based on sixteen 30 minute periods per day, approaches 1.2 i / c n ? . It is presumed chat the grinding tools used were not equipped with dust collection systems. The study further explains that, based on a sampling of 61 roofers, the median frequency of roofing with corrugated sheets, shingles, and front plate asbestos-cement building products, where grinding is not performed, are 34, 30 and 25 days per year-, respectively. It is noted that workers may handle more chan one type of asbestos-cement product on any given day. 16 Nilfiak of America, of King of Prussia, PA, a manufacturer of HEPA* filtered industrial vacuum cleaners for toxic materials, conducted a study demonstrating Che effectiveness of their shielded power hand cools in controlling dusting during use. The tools demonstrated, an electric drill, a circular saw, and a sabre saw, were equipped with specially designed dust collecting enclosures (shrouding) connected by flexible hoses Co a portable high efficiency vacuum cleaner. Airborne fiber concentrations were monitored during sawing and drilling of asbestos cement board. Only two sampling run# were conducted. The fiber concentration measured at the breathing rone of the operator during use of the circular saw was 0.04 f/cm^. The breathing rone fiber concentration recorded during the combined operation of the circular saw, drill, and sabre saw was 0.15 f/cm^. Sampling times for these two runs were 12 and 17 minutes, respectively. Both air samples were analyzed by phase contrast microscopy. Although it was not reported, it is presumed that the tool demonstration was conducted indoors. No visible emissions were observed from the cutting operation while the vacuum cleaner was activated. Johns-Manville Corporation conducted a monitoring a t u d y ^ co determine the magnitude of airborne fiber concentrations generated during drilling and sawing flat A/C sheet. The electric drill and circular saw used to cut a 0.64 cm (0.25 in.) thick piece of flat A/C sheet were equipped with dust collection vacuum exhaust systems. Each cutting operation was monitored separately for 40 minutes. Air samples collected are presumed to have been analyzed by phase contrast microscopy. The test results presented in Table 4 show that airborne fiber concentrations of <0.1 f/cm^ can be expected when A/C sheet fabricating activities are performed using tools equipped with dust control devices. SUMMARY OF FINDINGS The moderately high asbestos content (15 to 40 percent) of A/C sheet creates the distinct possibility for fiber release during physical alteration which can occur during material fabrication and removal. When in service, normally a static condition, the high percentage of cement in the product matrix strongly binds' the asbestos material together making fiber release unlikely. Secondary processing and field fabricating operations may be performed on A/C sheet products that result in asbestos fiber release. The magnitude of asbestos, fiber release during these operations depends on the intensity of the mechanical energy applied. Power tools increase the likelihood of fiber release because of their pulverizing affect on the material. The high speed action of cutting blades also causesgreater particle dispersal. Use of hand operated tools does generate dust, but the particles are coarser (tending to settle to the ground quickly) and the amount of physical energy applied is well controlled. *HEPA High Efficiency Particulate Air Filter (99.97 percent retention at 0.3 microns). 17 c TAH LF. A. AIRBORNE MONITORING RESULTS FROM USING A CIRCULAR SAW AND DRILL ON FLAT A/C SHEET23 Operation Time (min) Equipment Fiber concentration b (f/cm3) Drilling holes (163 holes) Sawing (18.3 meters) 40 Drill with dust pick-up shroud operated at full speed 40 Circular saw with dust pick-up shroud; totally enclosed masonry blade < 0.1 0.0 *AI1 teats conducted in an open room. ^NIOSH'a phase contrast analysis assumed, counting fibers 5 um long or longer with a length-to-diameter aspect ratio of 3 or greater. Secondary processors performing fabricating operations primarily use power assisted tools. These tools are typically equipped with individual or centralized dust collection vacuum exhaust systems. Workroom air fiber concentrations are expected to be below current occupational exposure standards. Because secondary processors are in the business of fabricating A/C sheet products, they perform various sawing, drilling, and sanding operations more frequently and over a more extended period of time chan any ocher product handling group. Material handling on any given day may last up to 4 hours, of which an estimated 3 to 30 minutes is actually involved in product machining. Fabrication of A/C sheet products by secondary processors is performed almost exclusively within the confines of a building. Rarely would Che machining operations be performed outdoors. Field fabricating operations, which are usually of short duration, are performed on only a small percentage (less than 5 percent) of the A/C material handled during installation. Depending on the activity performed and equipment available, dust control measures employed during field fabrication vary from no control to effective dust capture. Power assisted tools are more often used on the thicker, denser material whereas hand operated tools are used on thinner, flexible sheets. Airborne fiber monitoring data indicate Chat the use of power-assisted fabricating tools equipped with dust collection exhaust systems effectively control Che release of asbestos fibers. Fiber concentrations of less than 0.2 f/cm3 have been measured during the use of controlled power tools. Uncontrolled power tools, however, have caused fiber concentrations as high as 41 f/cm3 near the breathing zone of construction workers. Table 5 summarizes the data presented on A/C sheet products and identifies the principal activity of concern with respect to fiber release. 18 TABLE 5. SUMMARY OF A/C SHEET PRODUCTS SECONDARY PROCESS I AND END USE ACTIVITIES Product: A/C sheet producta Secondary processing End use Activity: Sawing, drilling, sanding Saving, drilling, sanding Duration: Per Incident <5 to 10 seconds <5 to 10 seconds Daily Total 5 to 30 minutes (eat.) 5 minutes (est.) Fiber Releasability: High High Chemical Composition Moderately high asbestos content (15 to 40X) Same Physical Composition Hard, rigid material Hard, rigid material Disruptive Energy Usually high intensity mechanical input Varies from power tools to hand operated cutting devices Control Measure(s): Dust collection systems Varies from portable dust collection systems to no control Measured Fiber Concen trations (f/cra^) : Less than 2 f/cm^ expected in workroom, well documented values not available from literature Less than 0.2 f/cm^ when tools are equipped with dust collection devices; more than 2 f/cm^ when Cools are uncontrolled Environmental Setting: Fabricating operations are performed indoors Whenever possible, field fabricating operations are conducted outdoc-.i. Some will be performed indoors, however Activity of Concern Field fabrication of A/C aheet products using power hand tools that are not equipped with dust collection devices. 19 ASBESTOS-CEMENT SHEET PRODUCTS REFERENCES 1. Asbestos Information Aasociation/North America, Recommended Work Practices for Field Fabrication of Asbestos-Cement Sheet. January 25, 1980. 2. Krusell, N., and D. Cogley. Asbestos Substitute Performance Analysis. Revised Final Report. Prepared by GCA/Technology Division for U.S. Environmental Protection Agency, Office of Pesticides and Toxic Substances, Washington, D.C. February 1982. 3. Research Triangle Institute. Economic Impact Analysis of Controls on Certain Use and Exposure Categories of Asbestos. Draft Report. Prepared for U.S. Environmental Protection Agency, Office of Pesticides and Toxic Substances, Washington, D.C, under EPA Contract No. 68-01-5818, by Research Triangle Institute, Research Triangle Park, N.C. and PEDCo Environmental Inc., Cincinnati, OH. November 1980. 4. Johns-Manville Product Directory. Johns-Manville Corporation, Ken-Caryl . Ranch, Denver, CO. SP-123B, 1980. 5. U.S, Environmental Protection Agency. Development Document for Effluent Limitation Guidelines and New Source Performance Standards for the Building, Construction and Paper Segment of the Asbestos Manufacturing Point Source Category. February 1974. 6. Telecon. Alfred Netter, Vice President of Production, Supradur Manufacturing Corporation, New York, NY, with Peter Anderson, GCA/Technology Division, March 11, 1982. 7. Telecon. David Lucey, A/C Sheet Product Marketing Manager, Johns-Manville Corporation, Denver, CO, with Peter Anderson, GCA/Technology Division, March 24, 1982. 8. Johns-Manville Transite Product Brochure (BSD-31A 6-77). March 1976. 9. Telecon. J. Jones, Assistant General Manager, Cem-^FIL'Corporation, Nashville, TN, with Samuel Dulestky, GCA/Technology Division, January 31, 1980. 10. Telecon. Edward Conlon, Sales Representative, Erection Specialties Inc., Canton, MA, with Peter Anderson, GCA/Technology Division, March 11, 1982. 20 , President, Hines Flask Conpany, Cleveland, OH, GCA/Technology Division, March 10, 1932. Teleeon. Roger Klinger, Plant Foreman, Browne-Morse Company, Muskegon Heights, MI, with Peter Anderson, CCA/Technology Division, March 10, 1982 Teleeon. Robert Smith, Sales Representative, Brookside Company and Supply, Maynard, MA, with Peter Anderson, GCA/Technology Division, March U , 1982. I'alecon. William Logue, Sales Representative, Lampco, Inc., Waltham, MA, w lth Peter Anderson, GCA/Technology Division, March 11, 1982. ^ U f i s k of America, 201 King Manor Drive, King of Prussia, PA. ^heeler-Piiot International, 20433 Earl Street, Torrance, CA. '^lecon. Company Representative, Kevankee Scientific, Statesville, NC, **lth Peter Anderson, GCA/Technology Division, March 18, 1982. * leon. Robert Norton, Process Engineer, Johns-Manvilie Corporation, Nashua, NH, with Peter Anderson, GCA/Technology Division, March 11, 1982. leon. Company Reprsentative, Eiectro-Matic Products Company, 1''icago, IL, with Peter Anderson, GCA/Technology Division, March 10, 1982 1r,gley, D. et al. The Experimental Determination of Asbestos Fiber Size 'Istribution During Simulated Product Use. Final Report prepared by l,,;A/Technology Division for the U.S. Environmental Protection Agency. ''Ifice of Toxic Substances, Washington, D.C. May 1981. ''Jelsperger, K. et al. Estimation of Exposure to Asbestos-Cement Dust "" Building Sites. Study supported by the Umvelfbundesant, Berlin, l'*`uject No. 10401023/11, by the Commission of the European Community, *'<oject No. 298-781 ENVD, and by the Bau-Berufsgenossenschaften, * ^nkfurt. *"tra-laboratory Memo, Argonne National Laboratory. Asbestos Fiber ^"asureraents During the Nilfisk Power and Vacuum Demonstration. August 1979. Memo received by GCA/Technology Division, from Bruce Newman, ^llfiak of America, Inc., King of Prussia, PA. December 7, 1981. ^"bestos Information Aasociatioa/North America. Recommended Work ** act ice Procedures for Asbestos-Cement Sheet. Submittal to U.S. **"vironmental Protection Agency, Office of Toxic Substances, in response '* Commercial and Industrial Use of Asbestos Fibers; Advance Notice of *' 'posed Rulemaking. EPA Docket Number OTS 61005. wmiwwiiiwiB aaw w M ws a iwwaiilMWS SECTION 3 FLOORING PRODUCTS INTRODUCTION Asbestos-containing floor products are classified as resilient floor coverings and include vinyl-asbestos floor tile, asphalt-asbestos floor tile, and sheet vinyl flooring backed with ashestoe-containing felt. A discussion of the felt backing used for sheet vinyl flooring is presented in Section 7 under Paper Products. Asbestos-containing floor tiles and sheet vinyl flooring backed with asbestos felt are installed in industrial, commercial, institutional, and residential buildings. They may be installed on concrete or prepared wood floors, or over old tile floors, and are often specified for heavily trafficked areas such as kitchens, entry ways, restrooms, supermarkets, commercial plants, and offices. Asbestos Floor Tiles " The production techniques for the two floor tile products, vinyl-asbestos and asphalt-asbestos, are similar. They differ only in product composition, with asphalt-based tiles serving some special applications and uses when darker shades are permissible.-* Because vinyl-asbestos floor tile production accounts for most of the asbestos consumed by the floor tile industry-*, the following discussion relating to floor tiles will address only the vinyl product. This discussion, however, will apply directly to asphalt-asbestos floor tiles, as well. Vinyl-asbestos floor tiles are composed of asbestos, binders, fillers, pigments, and chemical stabilizers. *^ The asbestos content of the tile usually ranges from 8 to 30 percent by weight, or up to 635 grams of asbestos per square meter (0.13 pounds per square foot) of tile.*- Grades 5 and 7 chryaotile asbestos fibers are normally used. Polyvinyl chloride (PVC) resin serves ss the binder and accounts for 15 to 25 percent of the tile composition. Limestone and other fillers represent 43 to 73 percent of the product weight. The pigment content usually averages about 5 percent, but may vary widely depending upon the materials required to produce the desired c o l o r . C h e m i c a l stabilizers added to the product mix typically represent 1 percent'of the total product formulation. Floor tile production begins with dry mixing of the ingredients in a Banbury mixer to thoroughly blend all constituents. The mixture is then heated to 149*C (300F) to flux the PVC resin and create a coherent plastic 22 mass. This material is a mill where che Cile i cooled. Asbestos fibers tu. within Che vinyl plastic matrix, thereby isolating them from the external environment during use. Once cooled, the tile product is waxed, cut to size, inspected and packaged. Tiles are produced in sizes 23 cm (9 inches) square or 30 cm (12 inches) square, with thicknesses varying from 0.08 to 0.24 cm (1/32 to 3/32 inches). Asbestos floor tiles are very durable and may last for up to 30 years even in heavily trafficked areas.^ Sheet Vinyl Flooring Asbestos felt-backed sheet vinyl flooring is a resilient floor covering that is applied to subfloor surfaces in roll or sheet form. The sheet backing or flooring felt is an asbestos-containing paper product that is manufactured separately and forms the underlayment of sheet vinyl flooring. Asbestoscontaining flooring felts, which are produced on a conventional papermaking machine, are composed of approximately 85 percent asbestos (chrysotile) and 15 percent latex binder.^ Once manufactured, flooring felt may be sold without further processing or may be used to produce sheet vinyl flooring. Asbestos flooring felt is manufactured info sheet vinyl flooring products by applying a resilient polyvinyl chloride coating to one side of the asbestos felt using various extrusion coating and laminating and spread-coating methods.^ Once the coatings are applied, the sheet is passed through an oven where these layers are dried and gelled. The coated sheet is then decorated to enhance its appearance by passing, it over one or more engraved cylinders and/or several printing stations. The printed sheet then goes to a fusion step where the sheet is coated with a "vearlayer." The wearlayer is a homogeneous polymer application that provides an impervious surface for the finished product.2 The coated and printed sheet is next fed through an oven where the felt backing, the layers of latex and plastisol, and the wearlayer are fused into a single product. During fusion, the layer of plastisol foam may expand 2 to 6 times its original thickness, giving the sheet vinyl flooring its thickness and resilience. After fusion, these layers remain distinct, but are no longer chemically or mechanically separable.2 The vinyl sheet is then cooled, cut to size, packaged and shipped.*'6 SECONDARY PROCESS 1NG-- FABRICATION There is no secondary processing of the products within this category. Asbestos floor tiles and asbestos felt-backed sheet vinyl flooring are shipped directly from the factory to wholesalers and retailers who, in turn, sell directly to end users.5 END USE. ACTIVITIES ' As indicated above, vinyl-asbestos floor tiles and sheet vinyl flooring are used in industrial, commercial, institutional, and residential applications. Floor tiles can be installed either by professional floor 23 lit installers or home owners,, while Che sheet vinyl flooring is usually laid down only by professionals due to the difficulty involved in creating a perfect fit with che one-piece sheet.'8 The installation of asbestos flooring products, like most floor coverings, requires preparation of a subfloor that is smooch and free of surface irregularities. Subfioor preparation may involve minor alteration of the existing floor covering or partial or total removal. Subfloor Preparation and Removal Subfloor preparation is considered by many installers to be the most difficult and time consuming as well as the most important part of the installation job if one is to get a smooth, long lasting new floor.^ This activity also involves the greatest potential for asbestos fiber release if the existing subfioor is covered with an asbestos-containing floor product and the manufacturer's warnings against sanding are not heeded. Interviews with several flooring installers revealed that cocanon subfioor preparation practices run Che gamut from sanding or dry scraping without any persoaal protective equipment, to explicitly not sanding, to sanding while using a respirator. " *^ The majority of installers interviewed avoid sanding whenever it is economically or practicably possible. If Che existing floor is not or cannot be sanded, it is either removed using flat-bladed putty knives or covered with plywood, fiberboard, or masonite. Sanding or removal of the subfloor covering takes approximately 4 to 8 hours for a standard 2.7 by 3.6 meter (9 foot by 12 foot) room, although this figure varies considerably depending on the sire of the room and difficulties encountered in removing old tile.** Sanding and stripping machines, as well as flat-bladed putty knives, hammers, chisels, and scrapers are utilized in subfloor preparation."*- If the existing subfioor is covered with asbestos felt-backed sheet vinyl flooring, then the standard procedure is to "strip" the floor. This process involves removing the top two (wear and foam) layers of sheeting and splitting che bottom asbestos felt layer in half, along the horizontal plane. If the subfioor covering was glued over its entire area, then this procedure is relatively easy, since the felt has little vertical tensile strength and will split when pulled. During this process, the existing floor covering is cut into strips approximately 0.46 meters (1.5 feet) wide and each strip is pulled up and away from the subfloor. This separation process, which may have a high fiber release potential, leaves half of the felt in place and offers a uniform subfloor for the new flooring product. Tarkett, Inc.* of Whitehall, PA, a manufacturer of sheet vinyl flooring, recommends that the jexposed felt be vacuumed immediately after each strip is removed to collect loose dirt that may contain ashestos fibers. Tarkett Inc. recently purchased the Whitehall, PA facility from GAP Corporation's Consumer Product Group. 24 v*.of '.nAtwi If, instead of total surface gluing, the existing sheet vinyl flooring had only been pasted along its perimeter, then stripping vill remove the entire covering, leaving only split asbestos felt around the perimeter. This felt is either scraped up after it has been wetted (recommended practice) or it is feathered to provide a smooth subfloor/felt interface. The former technique is favored since feathering involves sanding the felt, which can release asbestos f ibers. If (a third acenario) the exiating sheet vinyl flooring is intact and relatively smooth, then its top layer will be used as the subfloor and be rough sanded to provide a better contacting surface for the adhesive. Sanding will disturb only the wear layer of the a sheet flooring and not the asbestos f e l t . ^ prepare sheet vinyl flooring is similar to The time that for it aa takes to asbestos remove or tile floor, approximately 4 to 8 hours for the standard size room. Installation Viny 1-Asbestos Floor Tile-- The installation of vinyl-asbestos floor tile in a standard 2.7 by 3.6 meter (9 by 12 foot) room will take a professional installer from 2 to 4 hours. 13 Installation is typically begun in the center of the room and proceeds toward the walls. Tile adhesive is applied over one section of the floor at a time and full tiles are applied. If the floor tiles are prebacked with adhesive, the protective cover layer is removed and the tiles are pressed in place. Once all full tiles are in place, the perimeter and partial pieces are measured and cut out. This requires proportionately more time than laying full tiles; up to one half of the total installation time is devoted to this detailed work.`^" ^ After partial pieces are marked, they are hand cut either by scoring the tile (cutting partially through) and snapping it or by simply cutting entirely through the tile in one operation. Whichever technique is used, the time spent in making each cut amounts to only 5 to 10 seconds. Total cutting time for an average 2.7 by 3.6 meter (9 by 12 foot) room is approximately 10 minutes. All cutting occurs in the room being tiled. Cutting tools include commercial tile cutters, utility knives, 7-- 1 1 1 7 * scissors, and razor knives. The low energy input associated with the uae of these hand tools and the binding properties of the tile matrix minimize fiber release during installation. Sheet Vinyl Flooring-- The installation of asbestos felt-backed sheet vinyl flooring in a standard 2.7 by 3.6 meter (9 by 12 foot) room will take from 1 1/2 to 6 hours depending on the width of the vinyl roll (1.8, 2.7, 3.6 or 4.5 meters), the way in which it is glued, and whether or not a pattern has been used.^~^ The narrower the flooring width, the greater the installation time since the patterns of adjoining sections must be matched. Gluing techniques, which were briefly described above, vary in three basic ways: fully pasted, whereby the i entire felt backing is glued to the subfloor; perimeter pasted, in which only the perimeter of the flooring is glued; and the "Put Down Quick" (PDQ) technique,, in which the flooring is layed without any glue. 6 A fully pasted floor will take the most time to install, but will last the longest. Perimeter pasting is used most often when the subfloor is concrete. This technique is quicker and saves time and money. A PDQ installation is more common to flooring which is solely vinyl than it is to the more expensive asbestos felt-backed product. 25 The use of a template for cutting sheet vinyl flooring ia a widespread practice. The template is cut to match the exact perimeter details of Che room. these details are then transferred onto the sheet vinyl product, Narrow strips of asbestos-containing flooring felt are often ujed as the template in aheet vinyl installations since it is readily available and ia relatively i n e x p e n s i v e . ^ Template preparation involves laying the template sheet along the perimeter of the room and transcribing onto it the perimeter outline. Each section of the template is cut on the spot and immediately refitted to the room perimeter to insure a perfect fit. Utility and razor knives are used for cutting the template, and this operation takes approximately 10 to 20 minutes of Che total l 1/2 Co 6 hour sheet vinyl flooring installation time for a standard 2.7 by 3.6 meter (9 by 12 foot) r o o m . I n s t a l l a t i o n time varies depending on the complexity of the perimeter details and the skill of Che installer. Once completed, the template pattern is transferred to the sheet vinyl flooring and the flooring is cut to shape and size. Razor knives and utility knives are also used for this purpose and the total cutting time is a fraction of Che total installation time, usually lasting from 5 to 20 minutes, again for the standard size r o o m . I n t e r v i e w s with flooring retailers and professional installers alike indicated that preparation and inatallation of sheet vinyl flooring involves minor mechanical disturbance to the product, minimizing the potential for airborne asbestos fiber release. The only action during installation that disturbs the asbestos felt layer of Che flooring ia cutting, and this is short in duration and not energy intensive. During use, Che asbestos felt layer ia never directly exposed. AIRBORNE FIBER MONITORING DATA Monitoring of asbestos fiber release during floor tile instillation and removal was performed by SRI International.**-' Results of this study are presented in Table 6.. The results of a similar SRI study, done on the installation and removal of sheet vinyl flooring, are presented in Table 7. The reported fiber concentrations for both studies were determined by phase contrast microscopy. Fiber concentrations associated with the two asbestos floor tile end use activities ranged from 0.0 to 0.58 f/cm3. The high end value was recorded when recommended practices were not followed during removal. Concentrations for the two sheet vinyl flooring activities were somewhat higher, especially those obtained during removal of the asbestos felt layer, up to 2.17 f/cm3 for dry scraping of the felt layer. According to the Resilient Floor Covering Institute, dry scraping is not a recommended work practice. The higher fiber concentrations recorded for the asbestos ffclc-backed sheet vinyl flooring product is expected because the felt backing contains a much higher percentage of asbestos (85 percent) than the tile product. (8 to 30 percent) and is not as structurally cohesive as the tile. Monitoring of fiber release during floor tile use and maintenance has been performed by SRI and Sebastien et al.*^ SRI'a results, presented in Table 6, show that fiber concentrations ranged from 0.00 to 0.195 f/cm3 during in-aervLce use, wet mopping, and machine buffing vinyl-asbestos floor tiles located in an office building's copy center and snack shop. 26 TABLE 6. PIBER RELEASE FROM VINYL-ASBESTOS FLOOR TILE INSTALLATION, USE, MAINTENANCE, AND REMOVAL18*19 Site description Age of tile (year*) Operation Sampling time (minutes) Fiber concent ration range (f/cm^) Residential home Residential home Residential home Residential home Office building copy center Office building snack shop Office building copy center Office building snack shop Office building copy center Office building snack shop Residential home Residential home 6 Old tile preparation 10 for new installation 0.000 New Installation 113 to 114 0.092 to 0.184 New Installation 220 to 232 0.081 to 0.267 New Installation 65 0.048 to 0.189 5 In-service use 411 to 419 0.002 to 0.011 5 In-service use 130 to 133 0.008 to 0.062 5 Maintenance - mopping 15 0.135 5 Maintenance * mopping 21 0.195 5 Maintenance - buffing 11 to 30 0.000 to 0.092 5 Maintenance - buffing 21 0.000 NR Remova1 123 to 134 0.062 to 0.147 6 Removal11 80 0.153 to 0.583 "Phase contrast microscopy analysis performed. Samples were taken at breathing rone of operators except for those taken in the office building copy center and snack shop, these were taken from 0.3 to 1.5 meters (1 to 5 feet) above the floor surface. "Removal deviated from recommended procedures that include removal without sanding, use of a flet-bladed wall scraper instead of equipment that would unduly shatter the tile, and not breaking the tile by hand before placing in a disposal bag. NR " Not reported TABLE 7. FIBER CONCENTRATIONS ASSOCIATED WITH THE INSTALLATION AND REMOVAL OP SHEET VINYL FLOORING BACKED WITH ASBESTOS FLOORING FELT20,21 Age of vinyl aheeting 1 * and sethod of attachment ' Sampling time Fiber concent rat ion* range Sita daacription (yeara) . Operation (sinutes) (f/cs3) Residential home - kitchen Residential hone - kitchen teaidential hone - kitchen teaidential hone - foyer teaidential home - kitchen teaidential home - kitchen Reaidential hose - foyer Reaidential hose - kitchen Reaidential hose - kitchen Reaidential hone - kitchen ReaidentLal hose - kitchen Reaidential hose - kitchen Hew adhered 6~adhered 13-adhcred 2-adhered 8-adhered 13-adhered 2-adhered 8-unadhered 6-radhe red 6-adhered 6-adhered 6-adhered Inatallation Installation Installation Installt ion Inatallation b Partial rovl b Total raaoval Total removal** Wear layer removal Wet acrape felt layer Dry scrape, felt layer Dry acrape felt layer 175 to 177 100 58 to 60 177 to 179 44 to 45 44 to 62 121 to 123 74 to 76 70 to 75 55 63 40 to 45 0.246 to 0.310 0.000 0.613 to 0.655 0.075 to 0.554 0.325 to 1.016 0.190 to 0.408 0.368 to 0.402 0.069 to 0.100 0.084 to 0.218 0.484 1.267 to 2.168 1.004 to 1.126 `Phase contrast microscopy analyala performed. Samples were taken at breathing cone of operators. ^Operations were performed according to Resilient Floor Covering Inatituta practicea that do not includa aanding, sweeping, or dry-scraping. . Because Che air sample, obtained by SRI were analyzed by ?CM, actual asbestos fiber concentrations were not determined. However, monitoring results obtained by Sebastien et al. indicate that asbestos fibers are released from vinyl-asbestos floor tiles during everyday use. Sebastien et al. performed air sampling at four locations within an office building containing 5,400 m of vinyl-asbestos floor tile. Transmission electron microscopic analysis of air samples taken during periods of active building use revealed airborne asbestos concentrations of 8, 21, 25 and 170 ng/m^* at the four locations, respectively. The locations sampled included three corridor sites and a fourth aice located in a workshop where electronic machines are tested and part of a corridor. The highest concentration was recorded in the workshop, an area of greatest worker activity. No fibers longer than 3 ya were observed on the membrane filters analyzed.^ Fiber concentrations measured during the removal of old asbestos floor tile are present-: : in Table 6. As evident in the table, concentrations resulting from removal are significantly higher than those associated with the installation, use, and maintenance of this flooring product. This is consistent with the amc-nt of energy expended in removing the tile. When an existing tile floor is removed, pieces of tile may remain affixed to the floor. To remove these pieces, a worker may use a hammer and a chisel to free the individual bits of tile from the adhesive binder. Alternatively, the worker may elec: to use an electric sender to sand the tile down to the existing subfloor deck. In either case, substantial amounts of mechanical energy are applied to the floor tile to effect its removal. This action, particularly sanding, may expel asbestos fibers from the vinyl matrix, resulting in elevated (higher than background) airborne fiber concentrations. Two monitoring studies on the release of asbestos fibers from vinylasbestos floor tile have also been conducted by CCA/Technology Division. One revealed asbestos fiber concentrations of 0.02 to 0.10 f / c w? during vinyl-asbestos floor tile r e moval.^ Sampling occurred approximately 4.5 to 6.0 meters (15 to 20 feet) from an area where workers manually ripped up an asbestos tile floor. . The ripping activity was monitored for 165 minutes. Air samples obtained were analyzed by SEM/EDXR. The other GCA s t u d y ^ involved measuring fiber concentrations during the reenactment of various end use activities on vinyl-asbestos tiles. The activities, which were performed in a laboratory glove box, included cutting, grinding, breaking, and drilling. Sampling periods ranged from 1 to 5 minutes. Initial analysis by phase contrast microscopy indicated no fiber release. When duplicate samples were analyzed by SEM (5000X) and EDXR, a fiber concentration of 0.5 f/cm3 was recorded for the tile grinding operation only. No fibers were detected by SEM/EUXK analysis for the other activities monitored. It is noted that even though SEM/EDXS. analysis was performed, only fibers .>5 vm in length and having a length-to-diameter ratio of 3-to-l or greater were counted. EPA'a factor for converting nanograms to fibers it 1 nanogram equals 30 fiber s . ^ 29 ^Murrp1hay et floor tile.to tall._ m_o_n_itored fiber rel~ease during The experiment was performed under sanding of laboratory a viny1-asbeatoa conditions in 3 x 3.7 x 2.1 meter (10 x 12 x 7 foot) walkin chamber. A belt sander was used to remove a section of old floor tile. The data indicate thcc sanding can result in airborne fiber concentrations of 1.2 to 1.3 f/cm.^ Air samples were analyzed by PCM, SUMMARY OF FINDINGS Airborne fiber concentrations measured during the installation of vinyl-asbestos floor tile and sheet vinyl flooring backed with asbestos flooring felt approach 1.0 f/cm^, as determined by PQi. During product installation, the product matrix containing asbestos fibers is disturbed by a limited number of manual cuts, each of which lasts only 3 to 10 seconds. Total cutting time amounts to 10 to 20 minutes of the total 1 1/2 to 6 hour flooring installation time. The rooms in which this cutting activity occurs are typically well-ventilated. Discarding sanding and dry scraping operations, fiber concentrations associated with floor tile removal (0.15 f/cm^) are approximately the same as those associated with tile installation, (0.05 to 0.27 f/cm-*) while asbestos concentrations attributable to sheet vinyl flooring removal (up to 0.48 f/co^) are approximately half those recorded during installation (1.0 f / z a ? ) . VThea sanding or dry scraping are employed to remove vinyl-asbestos floor tile or sheet vinyl flooring during subfloor preparation, airborne fiber concentrations of 1.0 to 2.0 f/cat , as determined by PQ4, can occur. Table 8 summarizes the data presented on flooring products and identifies the activities of concern with respect to airborne asbestos fiber release. TABLE 8. SUMMARY OF ASBESTOS FLOORING PRODUCTS SECONDARY PROCESSING AND END USE ACTIVITIES Product: flo o rin g pro duct: aabeatoa flo o r t i l , boat Tiny1 backed w ith aabeatoa f a it Secondary proceeaing ic tir ltjr i D uratloa o f i c t l r l t y i fa r Incldant D aily T o tal fa r Incldant D aily T o tal fib a r K alaaaab llity : C henical C oopoaition Mo aaco n d ary p ro c a a a lo g fo r a itb a r product lin a Su bfloor p rap aratio n / raaoval In a ta lla tio o (cu ttin g ) fb y a ica l C oapoaitlou > D iim p c iv t ItM rgy Su bfloor p rap aratio n / raaoval ln a ta llg tio n (cu ttin g ) Control Haaauaai Su bfloor p rep aratio n / raaoval In atallaclo n (coatinu ad) ~ flo o r t il End uaa Sheet vinyl flo o rin g Su bfloor prap aration/ raaoval, in a ta lla tio o Su bfloor p rep aratio n / raaoval, in a ta lla tio o 1U HA 4 to S boura 4 to 8 boura 5 to 10 ceconda Sonewhat continuoua 10 ainu taa 10 to 20 ainu taa Low M oderate S t o 30X a a b a a to a , t i g h t l y bound in p o ly a a r ra a in 85X a a b e a t o a , bound by la ta a binder M oderately p lia b le , a t i f f , hard, vary coheaiva Very p lia b le , not rig id Hand c h t a e l l n g and a cra p in g , nay uaa power to o la (aander) Hand h e ld c o r in g k n i f e , t i l e c u tte r, acleaora Hand a c r a p in g , nay uaa power to o la (aan d er) Raaor knivea, aciaaora W attin g, follow ing recoaaanded work p r a c tic a a fo llo w in g recoueeodad work p r a c tic a a , no angioaarim con trol W ettin g, follow ing recoaaended work p r a c tic a a fo llo w in g recoaaaended work p r a c t i c e , no engineering control TABLE 8 (continued) Product: Flooring prodvcc: aab cito i flo o r t il , bt vinyl b aclt^ with aabaatoa i U Stcoiw laiy f r o c n io | Floor t i l e End uao Sheet vinyl flo o rin g Heaaurvd f i b e r C o n cen tratio n (f/c n 1) : i Bubfloor p rap aratio o/ nooval In stallatio n U*, a a in tto a o e t 0 to 0 .1 J* 0 .0 3 to 0.27 0 .0 0 to 0. 70 . (8 to 170 ng/n^ ) 0 .0 7 to 0.4 8 * 0 to 1.0 NO Environmental t a t t i n g : lo d o o ra . In room u a u a lly w ell v en tila te d lodoora, in roon uau ally w ell v e n tila te d ' A ctiv ity o f Cooctm S u b flo o r p r e p a r a tio n in v o lv in g re n o v e l o f a a b e a to a f l o o r t i l e o r a h e e t v in y l f lo o r in g backed w ith a a b a a to a f a i t whan raco w en d ed work p ractlcaa are not follow ed* ` Whan f o llo w in g racoawMndad work p r a c t i c e * . ^BPA'a f a c t o r f o r co n v e rtin g nanograaa t o f ib e r i * 1 nanogran e q u a l* 30 f i b e r * . ^ HA Hot a p p l i c a b l e . HI) m Ho d a t a . FLOORING PRODUCTS REFERENCES Krusell, N. and D. Cogley. Asbestos Substitute Performance AnalysisRevised Final Report. Prepared by GCA/Technology Division for the U.S. Environmental Protection Agency, Office of Pesticides and Toxic Substances, Washington, D.C. February 1982. The Resilient Floor Covering Institute. Comments on fche Advance Notice of Proposed Rulemaking on the Commercial and Industrial Use of Asbestos Fibers, Washington, D.C. February 18, 1980. Meylan, W. M. et al. Chemical Market Input/Output Analysis of Selected Chemical Substances to Assess Sources of Environmental Contamination, Task III-- -Asbestos. Prepared for U.S. Environmental Protection Agency, EPA Report No. EPA-560/.6-78-005. August 1978. 4. Arthur D. Little Co., Characterization of the U.S. Asbestos PaperB Markets, Prepared for the Minister of Industry and' Commerce-- Government of Quebec. Final Draft Report to Sores, Inc., Montreal, Canada, Report C-79231. 1976. 5. Written response from Congoleum Corporation, Resilient Flooring Division, Cedarhurst, MD, to Robert Mclnnes, GCA/Technology Division, April 26, 1982. 6. Written response from Tarkett, Inc., Whitehall, PA, to Robert Mclnnes, GCA/Technology Division, April 28, 1982. 7. Telecon. Company Representative, Wayne E. Anderson Company, Inc., Tewksbury, MA, with Robert Mclnnes, GCA/Technology Division, March 11, 1982. 8. Telecon. Steven Cantor, Sales Representative, Tile City, Waltham, MA, with Robert Mclnnes, GCA/Technology Division, March 11, 1982. 9. Telecon. Company Representative, ABCO of New England, Waltham, MA, with Robert Mclnnes, GCA/Technology Division, March 12,-1982. 10. Telecon. Company Representative, Belmont-Waverly Floors, Belmont, MA, with Robert Mclnnes, GCA/Technology Division, March 12, 1982. 33 11* Telecon. MA, wich 12. Telecon. with Robe 13. Telecon. Company'Representative, Harvard Floor Craft, Cambridge, MA, with Robert Mclnnea, GCA/Technology Diviaion, March 10, 1982. 14. Telecon. Company Representative, Joseph Silverman and Company, Inc., South Boston, MA, with Robert Mclnnea, GCA/Technology Division. March 18, 1982. 15. Telecon. Company Representative, Medford Floorcraft, Medford, MA, with Robert Mclnnea, GCA/Technology Division. March 18, 1982. 16. . Telecon. Company Representative, Congoleum Corporation, Trenton, NJ, with Robert Mclnnea, GCA/Technology Division. March 18, 1982. 17. Telecon. Bernard Ramundc; Vice President-Engineering, Kentile Floors, Brooklyn, NY, wich Robert Mclnnes, GCA/Technology Division, March 10, 1982. 18. SRI International. Monitoring for Airborne Asbestos Fibers: Vinyl Asbestos Floor Tile. Prepared for Resilient Floor Covering Institute. Washington, D.C. SRI Project 7988. December 1979. 19. SRI International. Comparison Testing Monitoring for Airborne Asbestos Fibers: Vinyl Asbestos Floor Tile. Prepared for Resilient Floor Covering Institute. SRI Project 7988. December 1979. 20. SRI International. Monitoring for Airborne Asbestos Fibers: Sheet Vinyl Floor Covering. Prepared for Resilient Floor Covering Institute. Washington, D.C. SRI Project 7988. December 1979. 21. SRI International. Comparison Testing Monitoring for Airborne Asbestos Fibers: Sheet Vinyl Floor Covering, Wet Versus Dry Scraping. Prepared for Resilient Floor Covering Institute. Washington, D.C. SRI Project 7988. December 1979. 22. Sebastien, P. et al. Indoor Airborne Asbestos Pullution: From the Ceiling and the Floor. Science, Vol. 216. June 25, 1982. pp. 1410-1413. 23. U.S. Environmental Protection Agency. Support Document-AsbestosContaining Materials in Schools -- Health Effects and Magnitude of ` Exposure. Office, of Pesticides and Toxic Substances, Office of Toxic Substances, Washington, D.C. June 1981. pp. 95-- 98. 34 24. Roy, N. et al. Asbestos Product Test Results. Draft Final Report, Prepared by CCA/Technology Division for the U.S. Environmental Protection Agency, Office of Toxic. Substances, Washington, D.C. February 1980. 25. Cor,ley, 0* t l. The Experimental Determination of Asbestos Fiber Size Distribution during Simulated Product Use. Revised Draft Final Report. Prepared by CCA/Technology Division for the U.S. Environmental Protection Agency, Office of Pesticides and Toxic Substances, Washington, D.C. October 1981. 26. Murphy, R. L. et al. Floor Tile Installation as a Source of Asbestos Exposure. American Review of Respiratory Disease, Vol. 104. 1971. 35 SECTION 4 COATINCS AND SEALANTS INTRODUCTION Asbestoa fibers are used in che manufacture of coatings and sealanta because of the strength, durability, thermal and corrosion resistance, sound deadening, and waterproofing characteristics they impart. Coatings are covering products used to rejuvenate and/or protect various types of surfaces. Sealants are liquid or semiliquid fillers used to fill gaps in building construction, vehicle components, and industrial equipment. Table 9 lists the applications of several coating and sealant products and the asbestos characteristics that make them desirable. The products within this category can be divided into two subcategories based on their composition: those which are petroleum based and those which have a water soluble latex or gypsum base. Petroleum-Based Products Petroleum-based products primarily include asphalt and tar-based sealants. Product formulations vary widely depending on end use application. In general, petroleum sealants are comprised of 5 to 30 percent asbestos (primarily chrysotile) and 55 to 80 percent cut asphalt. Other petroleum derivatives added to achieve the proper consistency required for the intended end use are naphtha, mineral spirits, and lighter-weight solvents. Other ingredients include rust proofing chemicals, pigments, heat reflecting powdered metals such as aluminum, emulsifiers, resins, and clay fillers.^ Sealants are produced in batches under a controlled production cycle. Initially, the fibers are fluffed prior to being charged to a batch blending tank where they are mixed with asphalt or tar and other additives, as required, for an even dispersion. After blending, the liquid product is pumped to dispersing operations and- finally shipped out to market. The batch sizes produced vary from several hundred gallons for small manufacturers with one production line to several thousand gallons for Larger manufacturers with a wide product mix and several production lines.^ The batch sizes'also vary with company size, type of product, method of containerization, type of production equipment, and size of order. Sealant manufacturing is often not a full-time operation but rather run part-time. This is due to seasonal fluctuations in demand, a greater amount of sealants may be produced in certain months of the year than in others* 36 Uee - Di*cin3-u.*hing cbarac ceriatie* of aabeatoa* Roof coating* \ Roof coentab Flashing cements^ V Chimney (tack, paint*b Automobile and truck uodercoating* Appliance inaulating coating* Corroaion-reaiatant coating* (re*i*tant to alt solution* including seawater ipray, organic acid*, iaeral acid, petroleum product*) A, E, C A, G A, G B. E, C A. B, e , r, c . E. T B, C Waterproof coating* for underground pipeline*, concrete foundation*, tide valla, tank*, and other atructure* auch a* mobile home* and cooling tower* in nuclear power plant* A t C| E, G Anticondenaatioa coating* for low temperature refrigeration aervica* B, C Til* cement* A Woodblock and'concrete floor maatice Sp*ckleb ~ Dry wall joint compounds^ Caulking compound* Texture p*int*b Sprayed-oo ceiling fini*heb r, c A, C, D A, C, 0 A| C, D A. C, 0 A f C, D Welding rod co*ting*b > B, E ^Letter* correspond with the characteristic* listed below. Stability, durability, and economy of eabesto* are relevant to all uaea lifted above. longer manufactured containing asbeitoe fiber*. Key: A. B. C. D. Strength Corroaion reiiatance Decay reaiatance Vermin reaiatance E. Thermal reaiatance F. Sound deadening C. Waterproofing 37 Weer Soluble Latex or Cypamn-Ba>ed Produce Produce under ehi aubcategory include joint compounds, patching pla aCer,^speckle, and drywall taping and finiahing compound^. Uae of this claas of compound has decreased significantly since the issuance of a Consumer Product Safety Commission (CPSC) ban of consumer patching compounds containing respirable free-form asbestos in 1977. The ban applies only to 'consumer' products, i.e., products that a consumer can purchase. The ban covers uses in residences, schools, hospitals, public buildings, or other areas where consumers have customary access.^ Patching compounds which are labeled as, marketed, and sold solely for industrial use applications are not subject to the ban. Two principal type of water soluble compounds have been produced. One used istex as the binder, which set by evaporation of the water. The other used dehydrated gypsum as the binder (and primary dry ingredient) and set by chemical reaction as the gypsum took up waters of hydration. The first type was mainly limestone with lesser amounts of mica and 3 to 5 percent asbestos. This type' was used by about 80 percent of the market, and was mostly sold in the ready-mixed, wet form. The gypsum-based material, capturing roughly 20 percent of the market, also usually contained asbestos and was sold dry, requiring wetting just before use. The worker mixed the compound with water in the field. Wet-mix products were manufactured and packaged in a can for ready use.^ Manufacture of both these products involved the usual handling of raw asbestos fibers where bags were stored, transferred, split, dumped, and fluffed. After dry blending, the latex-based products were wet mixed, binding Che fibers in the matrix. The dry mixed gypaum-based product, which was not wetted during manufacture, maintained the potential for fiber release throughout the manufacturing process, as well as during packaging, distribution, and end use.^ SECONDARY PROCESSING- FABRICATION There is no secondary processing of the products within either subcacegory. Once manufactured and containerized, the products are shipped to wholesalers and retailers who sell directly to end users. END USE ACTIVITIES PeCroleum-3ased Products Petroleum-based compounds include roof and horizontal surface coatings. roqJL^and flashing cements, automobile and truck undercoatings, waterproofing CQA-Cjinga, and floor mastics.* T&ese product are applied by contractors, specialty coating professionals (undercoating, roofing), and homeowners who buy Che product at local retail and hardware stores and lumberyards. The products may be applied by brush, spray gun, roller or trowel, depending on their consistency and intended use. The following discussion provides examples of some of the more common applications of petroleum-based sealants and coatings. ' 38 Asphalt and Car-based coatings and sealant. are ' . building and construction trades to protect exposed * ! ? s u r - - * ^ ** exterior building walls, and to patch existing roofing and si-.iM?' w*teTpror Asbestos-containing coatings are used in highly corrosive environments, such as those found in paper mills, to protect structural metal surfaces from attack by chlorine, chlorine dioxide, and moisture.** The coating is shipped to the site in premix form and applied using a high pressure airless acomization spray gun. Asphaltic-based asbestos sealants are widely used in the construction industry Co waterproof foundations and other subgrade structures, as well as in "back-up" walls, which are exterior walls that are ultimately covered by an architectural covering such as brick.^ Depending upon the amount of surface area to be coated and its location, the coating is applied either using brushes or spray equipment. For roofing applications, the asbestos sealant is used primarily for installing flashing or the perimeter of a built-up roof.^ It goes on after the roof covering material and is applied by a trowel. Asbestos sealants are also used in repair jobs, when, for example, a leaking chimney or roof must be patched. This operation is often performed by the homeowner and takes advantage of the ability of Che asbestos product to bridge a crack without subsequently drying, contracting and cracking again. A brush is most often used for this purpose. The activities just described occur predominantly outdoors or in large open areas within buildings. Application of the compounds may last from one half hour up to a full workday depending on the method of application and the size of area to be worked. Another use of petroleum-based asbestos-containing compounds is for protective undercoatings and sound deadening on automobiles and trucks. Application of these materials is commonly carried out inside an automotive' assembly factory or service shop using spraying equipment. Depending on the production schedule, material application may last from a few hours to a full 8-hour work shift. Spraying may occur in enclosed work booths or in an area open to the workroom environment. Although the asbestos content of petroleum-based compounds is moderately high, the potential for fiber release during application and in-service use is low. Fibers contained within these products are thoroughly wetted and remain bound by the tacky asphalt or tar matrix. The petroleum compounds of the product '.Lx effectively cover and bind the fibers together, minimizing the potential for free-form release during application.^ Most of Che petroleum-based products are applied as exterior surface coatings, upon which'no direct physical exertion is applied. Consequently, except for weathering, which is expected to have a minor effect on fiber release, Che materiel remains unaltered after application. 39 Hf.LeJ.,.s.o,lubie Latex_or Cypsum-Ba,^ p ^.I. > Water soluble asbestos-concaining coatings and sealants include such products as spackUng__compounds and drywall patching and tap.nz The latex sealing and coating products often come in premixed containers whereas the gypsum-based materials come dry and must be mixed by the user. Substantial fiber release can occur during dry product mixing, sanding, and clean-up, which, it is believed, contributed, in large measure, to the CPSC ban. The dry joint compound powder, where still available, is normally purchased packaged in paper bags. The bag is slit open with a knife and the powder dumped into a container. Water is Chen added according to the manufacturer's directions and the compound is mixed by means of a portable electric drill equipped with a mud or paint mixer bit. Some joint compound is sold as a paate (referred to as "premix") and only a small amount of water is required. The prepared mixture, in its putty-like form after wetting, is referred to as mud. The time spent mixing in a working day is short. It usually takes 5 to 10 minutes to mix a batch and in moat instances one to three batches are required daily.^ An initial or "embedding" coat of joint compound (mud) is spread acrosa the joint by a 2-inch putty knife. This is immediately followed by the application of a 2-inch wide perforated paper tape which adheres to the mud; the mud passes through the perforations, insuring intimate tape/mud contact. The tape/mud layer ia allowed to dry until it is thick and then is followed in succession by two additional mud coats. Each of these coats is feathered using putty knives until they blend with the wallboard surface.^ For large jobs, a joint taping machine is available which puts d-.wu the first mud coat, the tape, and the second mud coat in one continuous operation. The final coats are applied by hand. A skilled worker can put down an 8-foot joint in 2 to 5 minutes.^ A homeowner, however, may take up to 20 minutes for the same task. Sixty-five to 70 percent of the working day, or up to 5--1/2 hours, is spent performing this- operation.^ After the mud has dried, it ia sanded, as required, to leave a smooth connection between successive wallboards. Here again, the experience of the worker is evident, for if the final mud coat is feathered skillfully, no additional sanding is required.^ When sanding ia undertaken, a hand-held abrasive paper--covered sanding block is the most common tool employed. Electric sanders are not widely used since the mud, even after drying, is too soft for the high speed sander.^ Pole sanders, in which the sanding block is attached to the end of a long pole, may be used for hard-to-reach areas. Workers employed in the sanding operation may use face masks for dust control, regardless of whether or not the joint compound contains asbestos. It is estimated that 25 to 30 percent of the total joint application time is spent in sanding,^ or up to 2-1/2 hours of every 8-hour workday. Almost all applications of the water soluble products occur indoors. The debris and the dust accumulated on the floor resulting from the mixing, application, and sanding operations are generally cleaned up by dry sweeping. In many instances, especially in cases of commercial building and 40 AIRBORNE FIBER MONITORING DATA Petroleum-Based Products Airborne fiber concentrations measured during spray application and sand blasting removal of different types of asbestos-containing petroleum-based coatings are presented in Table 10. Operations monitored varied from spraying cutback asphalt containing 7.7 percent asbestos on a roof surface to sand blasting a 2.1 percent asbestos content high performance exterior resin coating from a steel tank.. As shown in the table, airborne fiber concentrations did not exceed 0.6 f/cm3. Another activity monitored involved sawing pipe coated with a polyester resin containing 2 to 3 percent asbestos. Measured fiber concentrations during this operation ranged from 0.04 to 0.1 f/cm . Water Soluble Latex or Gypsum-Based -Products A summary of airborne fiber monitoring data obtained during the performance of the end use activities associated with gypsum-based drywall compounds is presented in Table 11. The table breaks down fiber concentra tions into Che various steps of product use and handling. Fiber concentrations measured during dry mixing ranged from 9.0 to 59 f/cm3 . During application, concentrations of 0.4 to 1.3 f/cm3 were recorded. Fiber levels associated with sanding and sweeping operations ranged from 1.2 to 24.2 f/cm3 and 4.0 to greater than 41.4 f/cm, respectively. SUMMARY OF FINDINGS From the discussion above, it is obvious that water soluble latex or gypsum-based coatings and sealants pose a far greater potential for fiber release during end use than petroleum-based products. Airborne fiber concentrations associated with dry mixing of such water soluble drywall patching compounds can approach 60 f/cm3. Detection of such levels probably contributed, in part, to the 1977 decision by the Consumer Product Safety Commission to ban consumer patching compounds containing respirable free-form asbestos fibers. Because these materials are still used in industrial settings and may still be present in existing buildings, care mu9t be taken during ail phases of product handling-to minimize asbestos fiber release. Asbestos-containing petroleum-based coatings and sealants are applied in both exterior and interior settings by workers utilizing high pressure spray guns, "brushes, or trowels. The asbestos fibers contained in these products are thoroughly wetted by the petroleum-based liquids, greatly reducing the potential for free-form fiber release during use. Monitoring tests conducted during product application and,removal revealed airborne fiber concentrations 41 TABLE 10 FIBER CONCENTRATIONS ASSOCIATED WITH THE SPRAY APPLICATION OP ASBESTOS-CONTAINING PETROLEUM-BASED COATING PRODUCTS8 Aaboat oa-e ornia1n1eg product a c tiv ity porfonaod Spray-npptlod aaphaltic im ! coating Culbock cephalt ** ** 4apha11'-m m 11oo praying I c i l l 'i i f ro of log is coating# T w ro fi Tiimfl oo \ m placa (ep raf) Nnf oppi lo o t loo t h ip c o a tin g by pray a p p lic a tio n Dry d ock c o a t in g I f pray a p p lica tio n Coating pipa in te r io r - pray ap p licatio n P ib o r-g la a a pipa HPtt (K a a d r a l c o n t i c i hip co atin g baino u n ta tilo (apray ap p licatio n ) fainting building ta rla r (commre la i) Moaaurad lib a r concnnfration U/cmh Rota of tacca Ow r.tl. .1 K ti.it,/ * . 11. l iM (a.) a n a ly tic a l nothod Conanat 0.001 t . 0.15 0.01 to 0 . ) 0.1 t . 0 .4 0 .0 t . 0 .1 0 .0 to 0 .4 0 .2 0 .0 to 0 .2 0.1 * 0.1 to 0 .4 0 .0 to 0 .4 0 .0 to 0.04 1*74 197, 1974 1*14 1 0 1 4 ,1 * 7 * t* 7 4 ,1*7 5 ,1 *7 * 1*74 1*74 1*74 1174 1*74 1 * 7 4 ,1 * 7 7 343 to 432 Ml to 33 11 to 3 37 14 to 23 23 to 43 3 to 14 Waa cant race* (iiim il) Pbaao c o n tr a c t (lin o ni) Ru m c o o tn it (iimo>4) f t u ii coat root (limoni) Ru m contract ( im u m 4) Ru m co n tract (CCUMOd) nuca contract UccuMd) Rue* contract (aaetaaad) Ru m contract (aaaunnd) rocca con (a cci mod) R u m coni Uaetaead) Ramane weight of caheatea aa aprayad rangad from 1 .4 to 7 .7 , a fte r c u ri^ 9. 7 to 1 2. h f c i t f M i g h t o f U t t o i a t preyed 2,4, oftot curios 1.1 M onitoring porfom od io U rfiiM M onitoring f i r f o m t io * od In d ia n a M o n ito rin g p a r to m od in C olorado, cod Indiana N u ijlm U W iaco aata, O p a r c to r a p ra y lq g o u tc ld c cod under l h ip w ith c h o c to c -x o D tc ic ia g poiy m e i n , fo r e c o t c c h c c to c aprayal 1 .3 O p erato r opraping dock v i t i aa a a b n a to a * o a ta io l g epoay and coal I l f n L a tu m . One p a ren n t a i b c i t c i preyod O p e ra to r preying i a t a r i n r of 7.4, 11' and 30 cm d l a u a t a r pipa r i d aa a b o a to a * < o tc la ii* (1 pa rea ct) apaff cod c o a l t a r uitC ura O p e ra to r m on ito red war lavalvad I ru nning a u to m a tic prey machia . w ip in g m an d m l. 4 1 .4 parerne $$t cb nm ical m a le t c a t n a i a nee i f f l ^ a p p lie d Chemical m a ia ta o t n a ia C M dU i ' 0 . 7 pa re ant aaboatoa applied Alkyd m a in co a ta ia ia g 4 p an aci ahnatna nr v in y l-a cry lic lata c o n ta in in g 0 . 4 p a n a a t aabaatCC '12LLUL' A TABLE 10 (continued) 43 TABLE 11. SUMMARY OF AIRBORNE FIBER CONCENTRATIONS ENCOUNTERED IN THE DRYVALL TAPING PROCESS 6.9 Aabeatoa-coataiaiot ffW tt drywalt co ^ w a J U t if A) < i Motor oolubl dryvell co^oitai (Study I) A c tiv ity porfonaod Ifflic ilin N iai* (dry poanler) N iiio g (rm li) on* w *lo| fol aaadiag fo l* aodiog SweOplog m o . U , Dry a l i l a t (0.9 to 1. 9 a) Keod aaodiof (0.9 to 1.5 a) fol aaudiag (0.9 to 1.5 a) i fM .piot 0 .0 t . O ) Neaaured ( iW r coocaotracioo (ttcm h 0.4 la 1 .1 *.0 c . 11.4 l'.l t . 1.1 l . l t . 14.1 1 .1 C . 10.1 1.2 to 10.0 4.0 c . 14.1 14.1 I . 11.4 11.4 to i.0 1.1 t . U .* 1.1 to 11.1 41.4 ( m i t a i Data of toot . i* m i t. n u Durptioa of activity/ pliai clan A u a tytica l (uta) M t Mod , i* t . t i 10 t . I l fkaaa coutraal* fkaaa coetraat Com ercial oprtioa to.14.ot lot K ttlo c ms 4 t. 1 fkaaa coacraat Com ercial oporatioa u n t. u n 1*71 t . 1*71 1*7* 1*71 t . 1*77 l*?t im 1*74 1*74 1*74 10 t . >0 to to 1* 4 t . 11 * t . 10 10 t . 10 MI M m ira fkaaa coatraat fkaaa cootraat fkaaa coatraat fkaaa coatraat fkaaa coatraat fkaae coatraat ftiaa coatraat laaidaotiat a a tti* laaid aatial aattiog Co m i k la l oparatloa laaidaatial tatting Cnmarc j a l opa rat ioa Comercial oparatloa. fiber ra*a reported la aot laaa background la va te, which for Cbe iaac roaa rentad (rou 0.3 to 13.1 t/c m * C om ercial operation, fib e r range reportad ia not leaa background l v e lo , thick fo r the aauc roou ranged fro * 2.1 to 2.3 f/cu* Com arclat oparatloa. fib e r raaga reported ia not leaa background lvala which (or the tarn roou ranged frou 3.3 to 19.1 tJcm * Due to Heavy loading d u r i n g w e e p i n g , aaupling occurred 1 3 i o u t c a f t e r aueeping atoppad. A fter 3 3 the ueaaured fib e r level waa Ji-.'t t/cm^ ll^ n 3 iM g #r i o * e r with U o | t K - t ^ i i M U r aapact ra tio of 3 or greter Mr cott4 by Ml * Mot Soportad C B tltttt uicroacopy ranging from 0.0 to 0.6 f/cm^. Spray-applied petroleum-baaed .lootings and sealants containing more than 1 percent asbestos are the only products not banned from building construction use by the asbestos NESHAP r ijulation. Table 12 summarizes the data presented on coatings and sealants and identifies the principal activities of concern with respect to fiber release. 43 \ TABLE 12. SUMMARY OF COATINGS AND SEALANTS SECONDARY PROCESSING AND END USE ACTIVITIES Product: Coating. and aaalant. Secondary processing End use Petroleum-based products Water soluble products Activity: No secondary processing Spray application, hand Dry mixing hand application \ of either product line brushing and troweling, troweling, sanding sand blasting removal Duration: Per Incident Daily Total Continuous operation up to 8 hours per day Mixing-- 5 to 10 minutes Application-- up to 5 1/2 hours Sanding-- up to 2 1/2 hours Piber Releaaability: Chemical Compo.ition Low 5 to 30Z asbestos, 55 to 8dZ asphalt High 3 to 5Z asbestos, majority gypsum or limestone o Phy.ical Composition Tacky material as applied, Wet paste as applied, hard resinous finish when granular finish after dry drying Disruptive Energy Moderate to high, power sanding (sand blasting) of material off surfaces Moderate, hand sanding He.sured Fiber Concentrations (f/cm^): 0.0 to 0.6 Mixing-- 1.2 to 59 Application-- 0.4 to 1.3 Sanding-- 1.2 to 24.2 Sweeping-- 4.0 to >41.4 Environmental Setting: Usually applied out' of doors to exterior surfaces Applied indoors to wall surfaces Activity of Concern Hiring, sanding, and cleanup sweeping of water soluble products that are still available and applied to interior wall surfaces. COATINGS AND SE C A N T S REFERENCES 1. Krusell, N., and D. Cogley. Asbestos Substitute Performance Analysis. Revised Final Report, Prepared for the U.S. Environmental Protection Agency, Office of Toxic Substances, Washington, D.C., by GCA/Technology Division, February 1982. 2. Daly, A. P. et al. Technological Feasibility and Economic Impact of OSHA Proposed Revisions to the Aabestos Standard (Construction Excluded). Prepared for the Asbestos Information Association/North America by R. F. Weston Environmental Consultants. March 26, 1976. 3. Consumer Product Safety Commission, 16 CFR Part 1304 - Ban of Consumer Patching Compounds Containing Respirable Free-Form Asbestos - 42FR 63362. December 15, 1977. pp. 203-207. 4. Telecon. Company Representative, Electro Chemical and Engineering Company, Inc., Emmaua, PA, with Robert Mclnnes, GCA/Technology Division, March 24, 1982. 5. Telecon. N. R. Fernandez, Product Manager, Celotex Corporation, Tampa, FL, with Robert Mclnnes, GCA/Technology Division, March 24, 1982. 6. Verma, D. K . , and C. G. Middleton. Occupational Exposure to Asbestos in the Dryvall Taping Process. Presented in the Journal of American Industrial Hygiene Association, Vol. 41, April 1980. pp. 264-265. 7. Telecon. Technical Services Representative, Gypsum Products Division, Celotex Corporation, Tampa, FL, with Robert Mclnnes, GCA/Technology Division, March 24, 1982. 8. Testimony Prepared for A Public Hearing Before the California Occupational Safety and Health Standards Board. November 8, 1978. Source of testimony unknown. Information supplied to GCA by Johns-Manville Corporation, Denver, CO. 9. Fischbein, A. et al. 1979. Dryvall Construction and Aabestos Exposure. J. -American Industrial Hygiene Association. Vol. 40, pp. 402-407. 10. 40 CFR Part 61, National Emission Standards for Hazardous Air Pollutants. 38 FR 8820, April 6, 1973, as amended. 47 SECTION 5 TEXTILES INTRODUCTION Because asbestos fibers, after minimal conditioning, are processable on conventional textile manufacturing equipment, they are incorporated into all conventional textile forma, including: lap, roving, y a m , cord, thread, cloth, tape, tubing, wick, rope, and felt.* The special qualities afforded by asbestos fibers include fireproofing, chemical and dimensional stability, flexibility, and moisture, abrasion, and corrosion resistance. Asbestos-containing textile product- typically contain from 75 to 100 percent asbestos.2 Small percentages of cotton, rayon, and other natural or synthetic fibers may be blended with asbestos to improve spinnability and to impart the desired serviceability to the end product.^ Primary manufacturing of asbestos textile products is performed by the established conventional process or by the wet process. Most textiles are made by the conventional process either by the dry or damp method.2 Both methods are identical, except that during damp processing y a m is moistened to reduce fiber emissions. In the conventional process, various sire asbestos fibers are thoroughly blended prior to processing through a carding operation.^ The carding operation combs the fibers creating a relatively parallel arrangement called a fiber mat. This mat is pressed and layered into a lap. The lap is separated into thin, continuous ribbons called roving. Cotton, rayon, or other material may be added at this stage to strengthen the roving.2 The more newly developed wet process yields a product that tends to hold asbestos fibers more tightly than those produced by the conventional process, thus reducing workplace fiber concentrations. In this process, asbestos fibers are mixed with hot, soapy water in a hydropulper.^ The process yields a dense y a m by extruding the dispersion slurry and passing the material through apinnerettes. Wet processing eliminates the carding operation, the segment of the conventional process that generates a great deal of airborne, fibrous "dust. Many of the asbestos-containing textiles manufactured are used as intermediate materials to produce other products, such as electrical and thermal insulation, gaskets and packings, fire and heat protective clothing, 46 woven clutch facings, and brake linings. Table 13 identifies the products made using the primary asbestos-containing textile materials dejcribed below. Product applications are also presented in the table. Asbestos roving is loosely held together untwisted strands of lap. Aa shown in Figure 1, roving forms the building block, for almost all the other asbestos textile products. Asbestos yarn is roving that has been mechanically twisted and spun to give it tensile strength. This yarn may be twisted with ocher single yarns, wire, or ocher material to produce plied yarn which can be coated to produce thread or treated yarns. Asbestos wick is several strands of untwisted roving loosely twisted together. Asbestos tubing is made by either braiding or weaving several strands of asbestos yarns. The braided style is supplied in many diameters and textures and in several wail thicknesses to meet a variety of end use applications.^ Asbestos tape is a narrow woven fabric manufactured from plied yarn containing selvage edges (the edge of the woven fabric finished to prevent raveling). Aabestoa rope is made by twisting or braiding two or more strands of asbestos wick together tightly. Heavier ropee contain a binder to hold the twist. Braided asbestos rope is manufactured in three configurations: (1) by braiding one or more jackets of asbestos yarn over a base of asbestos rope or wick; (2) by braiding asbestos yarn braid over braid; and (3) by plaiting asbestos y a m into square cross section.^ Asbestos cord is usually twisted or braided asbestos yarn (a pre determined number of strands) which forms a cord of desired diameter and tensile strength. The y a m s used may be sized or unsized, plain or metallic (wire inserted), or single or plied depending on the end use of the product.^ Cloth woven from asbestos y a m and thread is soft, flexible, and stitchable, enabling it to be fabricated into protective apparel, blankets, shields, and exterior jackets for fiberglass batts placed around boilers, columns, and heat exchangers. In most cases, the asbestos textile materials identified above are surface treated with a resin or elastomer coating before shipment as a finished product.^ The materials can also be aluminized to give a heat reflecting surface. The metallic layer can be sprayed or bonded to the cloth by a thermosetting, resin. Treatment by either or both of these coating techniques effectively reduces the potential for asbestos fiber release during secondary processing and end use. SECONDARY PROCESSING-- FABRICATION Depending on,the product line, primary textile manufacturers may produce intermediate materials such as y a m and cloth that will be fabricated into a final product by a secondary processor or they may produce the final product themselves. Examples of the latter include tubing and tape used for thermal 49 TABLE 13. ASBESTOS-CONTAINING TEXTILES AND TTIT END USE APPLICATIONS2*56*7 Produce Application Textile material End use Fire and heat reaiatant materials Thermal insulation Electrical insulation Gssleets and packings Friction materials cloth, thread, yarn, roving Cape, tubing, cord, cloth, yarn yarn, roving, tape, thread, felts, cord, lab, tubing rope, wick, cord, cloth, tape roving, yarn, cloth Protective apparel (gloves, coats, hoods, and pants), blankets and draperies, conveyor belts, furnace shields, ironing board covers, hot metal splash guards, welding curtains, dryer felts and mats, hot pads Marine and industrial pipewrap and sleeves (lagging), diesel exhaust line and manifold covers, tool insulation (glassware), braided wall liners in steam hoses, fuel line insulation, hydraulic line insulation Electrical wire wrap and sheathing, multicore cable wrap and sheathing, motor winding insulation, heater cord insulation, core for electrical resistance wires, sleeving for electrical appliance leads All purpose shaft and valve stem packings, expansion joint gaskets, manhole and handhole boiler cover gaskets, oven and furnace door gaskets, chemical process vessel gaskets Industrial, truck, and marine clutch facings, heavy stress brake Lihing applications 30 I Figure Flowsheet for asbestos textile manufacturing. 3 51 Fire and H o t Resistane Materials The asbestos cloth supplied to fabricators of fire and heat resistant materials is often surface-treated to minimize fiber release during secondary processing and end use. Fabricators typically cut, sew, stitch, staple, weave, and grommet the "lint free" cloth into products ranging from space suits to welding curtains. Secondary processing is usually performed indoors within enclosed factory rooms using electrically powered machinery. Material processing will occur over a normal 8-hour work shift. The outside surface of woven textile products may be further treated by secondary processors to enhance certain product qualities. For example, asbestos-containing cloth may be aluminized to improve radiant heat characteristics or be given a polymeric coating to render it waterproof. Ocher treatment methods include painting and plastering.^- Each of these surface coating treatments reduces the potential for fiber release during subsequent processing and end uae. Thermal Insulation Secondary processing of asbestos textile materials used as thermal insulation is required for certain product applications. Fabrication of these products, such as braided walls of steam hose lines and hydraulic fluid and fuel line sleeve covers, occurs at factories that either distribute these products or have direct use for thera.*^ Secondary processing involves the use of electrically powered machinery over an 8-hour work shift. The use of engineering controls, such as total or partial enclosures which exhaust to a conventional particulate capture device like a fabric filter, will depend on whether the textile material has been surface-treated to minimize fiber release and the extent of dusting caused by the fabricating operation. Other duat control methods include dampening the material prior to processing and reducing machinery speeds. Once the asbestos textile material ia incorporated into a final product, such as a steam hose wall or fuel line cover, the potential for fiber release is extremely low. Under normal conditions, the asbestos textile is never exposed. Only during mishandling or when damaged whereby the textile material becomes exposed will fiber release become a potential problem. Electrical Insulation Asbestos yarn, t-hread, and tape are supplied to wire manufacturers for use as insulation material in the production of wire products. Wire^ manufacturers wrap asbestos textile material around wire or cables using electrically powered wrapping machines capable of producing thousands of feet of wire per day. As a conductor covering, braided asbestos tubing or tape may be wrapped on wire (or cables), or plastic laminated and pressed onto wire. 52 viga Generally, asbestos-containing texc Lies are used to insulate --iris nd designed for low voltage, high current use under severe temperature cond it ions.^ Although asbestos textiles normally used for wire insulation and ocher forms of electrical insulation are surface-treated, fiber release can be expected during product fabrication. During processing, the textile material is passed through various winding machinery that constantly bend and twist the material. Such handling will loosen the woven or twisted strands of the textile material, weakening its structural integrity. Continued agitation by the machinery can cause the release of fibers. Dust control methods implemented to minimize workroom contamination are similar to those described above for thermal insulation processing. Final processing involves applying a protective cover over the wound material. This encasing step greatly diminishes the potential for fiber release from the product during subsequent handling. Gaskets and Packings Untreated asbestos yarns are used by fabricators in the production of packings to prevent gumraing-up of equipment. Untreated y a m is braided by machine to form the packing material. Then it is passed through a heated resin or petroleum-based liquid bath to saturate the strands with lubricant. Lubricants can include teflon, graphite, or molybdenum disulfide. The treatment process is performed to maintain product pliability while in service and to prevent the abrasive asbestos fibers from scoring machinery shafts and valve stems during use . * ^ * ^ Unlubricated packing is used as gaskets. Because the potential for fiber release during the braiding of the untreated yarn is high, engineering controls, personal protective equipment, and appropriate work practices, such as reducing machinery speeds, are generally employed. Engineering controls include enclosing the braiding machines in ventilated rooms or booths and installing exhaust hoods at key material handling stations. Personal protective gear may include a separate set of clean work clothes and dust control face masks, when necessary. Friction Materials Asbestos yarn or cord, that may be reinforced with wire, is used to make woven clutch facings and brake linings. These products are mainly found in industrial applications where long periods of heavy load conditions exist or where short bursts of resistance are required.^ The asbestos textile is normally impregnated with phenelic resin or coated with asphalt prior to processing. After curing and drying, the treated yarn is then fed to mechanical winders, which are used to form the woven friction products. Because the yarn has been coated with the resin or asphalt-based compound, fiber release during*winding is expected to be minimal. END USE ACTIVITIES Asbestos-containing textiles are used in a wide variety of applications ranging from industrial furnace shields and hot metal splash guards to laboratory gloves (see Table 13). The following describes the end use activities associated with the more common asbestos textile products. 53 Fire and Heat Resistant Material.. Applications for fire and heat resistant asbestos cloth i .elude curtains, draperies, blankets, protective clothing, hot conv:-0r belts furnace shields, and molten metal splash protection aprons.3>a9 Kany*of these applications generally do not involve the performance of any activity that would cause airborne fiber release. All of the necessary stitching, sewing, and grommeting work is performed by the primary manufacturer or secondary processor. To install these products one simply hangs the material on support structures, as in the case of heat shields and curtains, or puts the clothing on, as with personal protective apparel. Material installation for static applications is estimated to last only a few minutes. Wearing protective clothing may last from a few minutes as in the case of gloves to several hours for heat reaistant suits worn in industrial plants or when fighting fires. Airborne asbestos fiber release is likely to occur with product wear. The life span of these various products ranges from many months to several years depending on the application and severity of wear. Moat applications are industrial, where harsh and strenuous conditions exist. As the material wears, the structural integrity of the woven fabric begins to fail allowing pieces of the material to unravel or become frayed. Thermal Insulation Asbestos textiles, such as cloth, tubing, and tape, are used as thermal insulation. Applications include pipe wraps for safety protection, stress relieving pads in welding operations, protective coverings for hot glassware utensils, coverings for hydraulic and fuel lines, and braided walls in the construction of steam hoses. Thermal insulating materials are generally used in static applications. Their woven and surface-treated construction minimizes the possibility of fiber release due to product degradation. The greatest potential for fiber release occurs during removal. Removal typically takes longer than installation and requires more cuts to extract the worn and sometimes encrusted material from the surface it was covering. A specific example of a thermal application involves the use of asbestos-containing textile tapes to insulate pipelines that transport hot liquids and gases. During installation, the tape is normally applied as a secondary insulator over a primary insulating coating of calcium silicate. Shears or knives are used to cut the textile tape. The number of cuts required depends on the surface complexity and the number of start and stop points. Cutting takes only seconds and accounts for only a few minutes of the total installation time. After the tape has been wrapped around the primary insulator, with edges overlapping, it is covered with paint or other sealant. Initial installation of the textile tape is almost exclusively performed by professional insulation contractors, whereas maintenance personnel will make repairs or renovations when they are required. The length of time for installation varies depending on the size of the job, lasting anywhere from less than one hour to a full work day.^ 54 w When Che time comes to remove che pipeline n practice Co thoroughly wet che insulation! vhich l e r v ^ ' U. a ' -fr control measure and facilicatea handling. After etc t is slit lengthwise using a utility knife or razor. ThI^terUl*il*!ita2 peeled off the pipe and discarded in drums or plastic bags.^ Another application, somewhat unique, involves the use of asbestos tape as a thermal insulator of process lines in a steel mill. A maintenance crew at a mill reportedly had to replace asbestos-containing insulating wrap around hoses carrying cooling water to the doors of an open hearth furnace every 3 to 4 weeks. The frequent need for replacement resulted from hot metal spills on Che hoses. Specifics about the removal of che damaged wrapping and the application of new tape were not provided in Che referenced citation. The high frequency of replacement associated with this operation is related to the extreme working conditions. Under less harsh conditions, thermal insulation applications using tape and tubing wraps are expected to last several years before replacement is required. Asbestos textile materials used as thermal insulation in static applications are not likely to release fibers to the ambient air under normal conditions. Generally, no abrasive force is applied to surface of the material that would disturb its structural cohesiveness. However, fiber release is likely during product removal if not properly controlled (e.g., thoroughly wetting material). Exposure to extreme temperature fluctuations, corrosive gases, or hot fumes over many years can physically age the asbestos material. The aging process weakens the structural cohesiveness of the textile material such chat fiber release during removal is likely. Textile materials used in dynamic (moving) applications, such as steam hoses and hydraulic lines are likely to release fibers if jacket walls or sleeve covers are cut or otherwise damaged such that Che asbestos-containing material is exposed. Continuation under these conditions will increase the potential for fiber release due to repeated agitation of the damaged or exposed material. Electrical Insulation Asbestos-containing textiles used for electrical insulation are normally incorporated into the internal workings of an electrical appliance or component. Rarely is the material exposed. In use, the textile material is usually held in a stationary position not subject Co direct wear or abrasion. With proper use, asbestos fibers are not expected to be released from electrical products containing asbestos textile insulating materials. However, if mistreated, the cloth covering of electrical appliance cords, for example, may become frayed exposing the inside insulating material. Continued misuse and abrasion to the exposed asbestos material may release airborne fibers. With respect to removal*at the end of its service life, the entire electrical appliance is discarded or the component containing the asbestos insulation is simply replaced. When damaged electrical components containing asbestos textile insulation need repairing, the whole unit, similar to above, 33 will be entirely replaced Co maintain 9v.Cem c . , repairs, such as replacement of damaged wire system may be all that is required. S p U c i ^ H'~ ------ old and new wire to expose Che enclosed metal filament. The '.JU e n e ^ i n p ! c involved in Cutting the wire and removing part of the insularing sleeve is expected to minimize fiber release from the asbestos material. Cutting of the asbestos textile using wire snips or scissors will take only a few seconds and result in a clean edge cut. After the new wire has been spliced with the existing wire, electrical tape is wrapped around the splice point(s) to insulate the wire. This step covers all exposed asbestos textile surfaces. Gaskets and Packings The following paragraphs focus on the end use of asbestos textiles as gasketing material, with a brief discussion on packings. A more detailed analysis of packings made from asbestos textiles is presented in Section 6 under Gaskets and Packings. Various asbestos-containing textile products are used as gaskets to seal expansion joints, boiler manhole and handhole (inspection) covers, commercial and residential oven doors, industrial furnace openings, and chemical process vesseIs. ^ The textile forms moat often used are rope, cord, wick, cloth, and tape. ` * These products are purchased from distributors in specified precut lengths, or if larger quantities are needed, wound on spools or coiled in boxes. Distributors of the textile gasket material cut desired lengths and punch pilot holes required for mechanical fastening at their outlet s t o r e s . C u t t i n g is done using shears or a knife; hole punching may be accomplished using a power-assisted or manually operated press machine. Other than possibly wearing a surgical-type face mask, no dust control measures are employed. ^ Installation of the gasketing product ranges from setting the rope into grooved tracks to bolting the tape to the mating surface. Cementing the gasketing to the mating surface using a furnace adhesive may also be performed.^ The gfVet material selected for use may or may not be surfacetreated. Rope used for this purpose tends Co be untreated whereas the tape is usually t r e a t e d . ^ Rope will likely have a cotton fiber carrier Co add structural integrity. When installing the new gasketing material, required lengths are first measured, then the rope or tape is cut using a knife, scissors, or tin snips. If the gasketing material is untreated, fiber release may occur when the material is pulled from the carrying spool or box.11 In use, the gasket material is not subject to any mechanical disturbance. However, changes in temperature, moisture, or chemical conditions will affect the material. These environmental conditions can. break down and 'cook out' the binders in the rope or tape causing them to degrade between the two macing surfaces. When manhole covers are opened, or pipe flanges separated, the inner portion of the gasketing will tear apart while the outer surfaces that were in contact with the mating surfaces may be baked on. Before installing new replacement gasketing, che old encrusted material must be removed leaving . . . . lns * smooth, clean surface. Flat edge pc:ty knives or wire brushes are used Co remove Che old material. Because asbejcos textiles have a high asbestos content (low binder content) and that the binders present may have reacted with various gases or been 'cooked-out', fiber release is expected during gasket removal. No monitoring data are available, however, to document this assumption. The length of time required to replace gasket material depends on the size of the pipe flange or manhole cover to be disassembled. The actual time involved in cutting new strips and removal of old material accounts for only a small percentage of the total job. Cutting is expected to last only seconds while material removal and surface cleaning are estimated to last several minutes (15 to 30 minutes); The frequency of gasket replacement also varies. Replacement may be required more frequently than actually needed due to the opening and closing of manholes or handholes as part of a routine maintenance program. Friction Materials Woven asbestos brake linings are found mainly in industrial brakes contained in cranes, lifts, excavators, winches, concrete mixers, and mine equipment. Woven friction products are also used as clutch facings for industrial band, plate and cone clutches in cranes, lifts,' excavators, and winches.^ Additionally, automotive brake pads may be manufactured from woven asbestos cloth which may be reinforced with brass wire or impregnated with phenolic r e s in.^ However, molded automotive asbestos-containing brake materials, developed in the 1950's, are replacing woven textile products because they offer superior frictional properties.^ Asbestos fiber release is not expected during the installation of woven friction products. The asphalt or resinous coating applied to the asbestos yarn prior to winding effectively prevents the release of asbestos fibers from an unused product during installation. Fiber release to the outdoor air during material wear is also not expected because woven friction products are usually contained within a metal casing, such as a transmission housing. The wear of a clutch facing, for example, depends on the amount of slippage that occurs since the clutch is basically a static friction couple that momentarily slides during gear shifts. Once the clutch cannot hold a continuous couple, it must be replaced. During product replacement asbestos fibers may be released to the ambient air when the friction material housing is opened and the worn out textile product is removed. Specific asbestos fiber monitoring studies have not been reported for woven friction product repair or replacement work.. AIRBORNE FIBER MONITORING DATA Although monitoring to determine airborne asbestos fiber concentrations during secondary processing is routinely performed by asbestos textile fabricator, the results of these studies are not readily available nor well documented in the open literature. Therefore, only a small amount of data is presented. 57 (deCe rmineU*by PCM) involving secondary p r e c e d i n g of a s b e ^ o i ' t u H t V * ! ! * ' a , -------are not likely Co be representacive of current w o r ^ l . c e ^ o n - ^ r ui.tLtutton of process modifications and improved control Cheae data were collected haa resulted in lower work place oncentrltion!* For example, the manufacturing modification involving vet-procesaing of asbestos textiles has resulted in lower airborne fiber concentrations during primary manufacturing and secondary processing.18 Fiber concentrations in the general workroom area and near an operator during the processing of asbestos cloth made by the wet-process were 0.46 and 0.90 f/cm1, respec tively. General area and breathing zone fiber concentrations recorded during cloth unrolling, measuring, cutting with scissors, and folding were 0.33 and 0.68 f/cm , respectively. Fiber analysis of all four air samples was performed using phase contrast microscopy.18 Airborne fiber monitoring data associated with asbestos textile end use activities are scant. Only a few atudies have been performed covering a limited number of textile products. The following presents the monitoring results that have been obtained from the literature. Tests to determine fiber release during the wearing of asbestos garments were performed at a blast furnace and a phosphorous plant where asbestos coats, hoods, and mittens are worn. Personal monitors were used to measure the concentration of airborne fibers at the breathing zone level. Fiber concentrations of 0.3 to 5.0 f/cm^ were recorded for a blast furnace worker with an 8-hour TWA concentration of 0.1 to l.l f/em^.19 At the phosphorous plant, fiber concentrations were considerably higher; 9.9 to 26.2 i / c a ? , with an 8-hour TWA concentration of 4.7 f/cm .^ No reason was given for the difference in concentrations recorded at the two plantsAirborne fiber concentrations were determined by phase contrast microscopy. The garments tested were made of an untreated fabric. Hoods, however, were aluminized on Che outside. The age of the garmeats was also examined in the study. Generally, asbestos fiber releai; increased with product age, however, no firm correlation could be developed. Measurements of fiber release from asbestos-containing fire-fighting helmets during use have been made.2 Products tested included a new helmet with an unlined surface, an identical older helmet, and a helmet with an aluminized covering on the inside and outside surfaces. Monitoring results revealed breaching zone fiber concentrations of 2.30, 1.38, and 0.0 f/cm^ for Che three helmets, respectively. Results of the samples analyzed by phase contrast microscopy clearly indicate that aluminization of asbestos cloth garments effectively controls fiber release during use of these products. Another study21,has similarly shown that woven asbestos textile gloves can release fibers during use. Asbestos textile gloves contain from 80 to 85 percent asbestos and 15 to 20 percent rayon. The gloves tested were surface treated with an acrylate-based compound, which enables the manufacturer (unknown) to market them as "lint free." 58 Three tests were performed as parc of the reLease monitoring experiments included: testis* chamber (glove box); a well-ventilated (five air chan^ea'per**^`v preparation room; and in university laboratories under condition!* glove use. The researchers examined the potential differences in release from new and worn glove.-j, the latter varying from clean to soiled. f heavily The glove use activities included the following: (l) picking the gloves up from a table top and putting them on; (2) opening an autoclave or oven door; (3) removing a tray containing laboratory growth media or glassware and setting the tray on a table top; (4) closing the door; and (5) taking the gloves off and tossing them onto a table top. The results of the three test cases are summarized in Table 14. In all cases, fiber release was found to be directly related to the condition of the gloves. Under the nonventilated isolation chamber conditions, the well-worn/clean gloves emitted almost three times as many fibers as did the new gloves, although the number of fibers released from the well-worn gloves decreased with increased surface soiling. TWA values calculated for the well-ventilated biology preparation room were considerably lower than those obtained in the ventless isolation chamber. The authors postulate that these levels result from dispersion of fibers within the room by the ventilation system. The findings of the biology preparation room testing concur with those of the ventless isolation chamber whereby the well-worr .'clean gloves released a significantly .higher number of asbestos fibers into the atmosphere than the new gloves did. Fiber concentrations also increased with work load, as one would expect. Monitoring tests conducted in various university laboratories revealed a wide range of fiber concentrations. The researchers state that airborne concentrations depended more on the particular laboratory than on glove condition or usage (work load). The range in values reported are thought to be attributed to differences in room size and configuration, efficiency of the ventilation ayscern, and amount of moisture oa the gloves. In another s t u d y ^ relating to thermal insulation application, Raybestos Manhattan Corporation of Charleston, SC, a manufacturer of asbestos textiles, measured airborne fiber concentrations of 0.01 to 0.05 f/cm^ during the cutting of untreated lagging cloth and counts of 0.0 to 0.04 i / c a ? during material application. Specifics about the activities performed and sampling and analysis procedures employed were not reported'. SUMMARY OF FINDINGS A. limited amount of airborne fiber monitoring of asbestos textile secondary processing and end use activities has been performed and reported in the literature. The majority of the available data relate to fire and heat resistant garments. Fiber concentrations reported for the breathing zone of workers wearing hooded fire protective clothing made from untreated woven asbestos fabri: ranged from 0.03 to 26,2 f/cm^. Other studies have shown 59 TABLE 14. AIRBORNE FIBER CONCENTRATIONS RESULTING FRO*. TEE USE OF ASBESTOS-CONTAINING GLOVES21 Sampling environment Condition of gloves and work load Fiber concentration Mean TWA SD (f/cm^T Isolation chamber (nonventilated) Biology preparation room (well ventilated) Breathing zone Work area University Laboratories Breathing zone Work area New Well-worn/clean Well-worn/lightly Well-vorn/heavily soiled soiled Hew - normal^ Well-wom/c lean-normal New - heavyc W e 11-wora/clean-heavy New - normal Well-wom/c lean-normal New - heavy Well-wom/c lean-heavy * Well-wom/c lean Well-wom/lightly soiled Well-wom/c lean Well-wom/lightly soiled 2.25 0.57 7.97 7 3.14 5.08 7 1.27 0.95 7 0.16 0.07 + 0.02 0.49 7 o.il 0.51 0.21 0.99 7 0.22 0.06 + 0.02 0.40 7 0.09 0.26 0.08 0.60 7 0.12 0.07 to 2.93d 0.10 to 0.71 0.04 0.30 to 0.74 Fibers counted were 5 um long or longer with a iength-to-diameter aspect ratio of 3-to-l or greater. Phase contrast microscopy analysis was performed. ^Normal usage of gloves, two times per hour. cHeavy usage of gloves, six times per hour. ^Values reported are not means; ranges are from tests`performed at five different laboratories. 60 X r-^rqj Chat Created c loch, particularly aluminization of the cloth surfics, greatly reduce fiber release. Monitoring conducted during the use of aluminized fire-fighting helmets revealed no fiber release. Studies performed on laboratory gloves made from woven asbestos cloth have shown Chat fiber release increases as the textile material begins to wear. Airborne fiber monitoring has demonstrated that well-worn, clean gloves release a comparatively higher concentration (0.49 i / c w ? ) of fibers into the ambient air than do new gloves (0.07 f/cm^) subjected to the same use. With respect to other textile products, monitoring during the cutting and installation of untreated asbestos-containing lagging cloth for thermal insulation revealed fiber concentrations of 0.01 to 0.05 f/cm^ and 0.0 to 0.04 t /cm?, respectively. The majority of the textile materials manufactured today are surfacetreated with various chemical coatings to minimize fiber release during use. Textile manufacturers and others have developed processes whereby the surface of Che material is impregnated with a proprietary compound during manufacture. This technique reportedly reduces Che release of airborne fibers by more than 75 percent when compared to untreated materials.^ Surface treatment also reduces unraveling after the material is cut or fabricated. Fiber release from asbestos textiles is likely, however, during mishandling or product abuse. Fiber release appears to be greatest from unsoiled, well-worn products. Table 15 summarizes the data presented for asbestos-containing textiles and identifies the principal activities of concern with respect to fiber release. 61 TABLE 15. SUMMARY OF ASBESTOS TEXTILE PRODUCTS SECONDARY PROCESSING AND END USE ACTIVITIES I Ov M K Product: Fire and heat reaiatant material* Secondary processing End use Activity: Duration: Per Incident Daily Total Sewing, stitching, stapling, cutting, or gronsseting woven textile fabric Installing material in place for worker protection or putting on, wearing, and taking off apparel. Fabricating operations will occur for up to 8 hour* per day at factory. Continuous us* throughout day or wearing for short duration* (e.g., gloves) Fiber Kalaasability: Chemical Composition Low to aoderate Asbestos woven fabric 73 to 100Z asbestos, usually surface treated Low Asbestos woven fabric 73 to 100X asbestos, usually surface treated Physical Composition Woven fabric, pliable Woven fabric, pliable Disruptive Energy Low torque aachlnery Hand applied Control Meaaure(s)} Engineering controls, personal protective clothing, workroom ventilation None, surface of material usually treated Measured Fiber Assumed to be less than Concentrations (f/ca-*): 2 f/c*^ within workroom environment 0.1 to 3.0 (1WA) for wearing heat protective clothing 0.1 to 3.0 (TWA) for using asbestos laboratory gloves Environmental Setting: Activity of Concern Indoors, open room of factory Indoor* or outdoors, industrial or laboratory setting Handling or wearing worn, uncoiled material (continued) TABLE 15 ( c o n t in u e d ) Product: Thermal insulation Secondary processing End ui* i Activity: In general, no Cutting, wrapping, reaoval aecondary processing Duration: Per Incident Daily Total I I Cutting - few seconds, totaling ainutes : Wrapping - aiinutea to hours ( Renoval - ainutes to hours Pibar Relaasability: Cheaiical Composition Low during cutting - nay be high during reaoval 73 to 100Z asbestos content, usually surface treated Physical Coopoaition Twisted, woven, or braided; pliable Disruptive Energy Hand cutting, ripping Control Heasure(s): o> u Measured Fiber Concentrations (f/ca^): Wetting posaibly during reaoval Crip-out')' 0.0 to 0.03 for cutting and installation Rnvironaental Setting: Mostly industrial applications occurring indoors Activity of Concern Renova l of worn out aatarlal (continued) TABLE 15 (c o n tin u e d ) Product: Electrical inaulat ion Secondary processing End use Activity: Minding or sheathing of wire, cables, cords, other electrical components ' Intended use of electrical appliance /component Duration: Par Incident Daily Total Up to 8 hours per shift Continuous use whenever electrical appliance/component is activated Fiber Releaeabllity: Low to moderate Low Cheaical Composition 75 to 100S asbestos, Sa n Physical Composition Pliable, asbestos textile contained in finished product is not usually exposed Same Disruptive Energy Winding machines Static end use application Control Measure(a): Engineering controls, personal protective clothing, work practices None Measured Piber Assumed to be less than Concentrations (f/cm^): 2 f/cm^ within workroom environment No data reported Environmental Setting: Indoors, open room of factory. Indoors or outdoors Activity of Concern Miahaodling, abuse of electrical appliance/coaponent such that inaulation becomes exposed and frayed. (continued) TABLE 15 (c o n tin u e d ) Product: Caakata and packinga* Secondary proceaaing Sod uae i Activity t Ho. secondary proceaaing Cutting, removal Duration: Per incident Daily Total Few aecooda per cut totaling 5 minutes, 15 to 30 minutea for removal fiber Relaaaability: Cheaiical Compoaition * Moderate 75 to 1002 aabeatoa-many gaaket applicationa will uae untreated rope Pbyaical Compoaition Pliable, woven or unwoven Diaruptlve Energy Hand cutting, craping during removal Ot Control Heaaure(a): Ul Heaaured Fiber Concentrationa (f/cm^); None No data reported Environmental Setting: Induatrial applicationa, moatly indoora Activity of Concern Removal of worn gaaket and cleaning of adhering material from mating aurfacea. *G(itati only jirtitatad, unary of packinga la praaanted in Saction 6. (continued) m TABLE 15 (continued) Produce: Friction materials Secondary processing End use I Activity: Coating asbestos yarn Installation, with asphalt or other wear, removal compound, followed by winding coated yarn to fora woven product Duration: Par Incident Daily Total Secondary processing activities will occur up to 8 hours par shift Installation (estlaated 1/2 hour to 4 hours) Wear intermittent - product lasts days, years Removal (estimated 1/2 hour to 4 hours) Fiber kcleaaability: Low to moderate Low Cheaical Composition 75 to 100X asbestos 3*m yarn coated with asphalt a* Fhyaical Coapoaition Rigid structure with Same c* tacky surface Diaruptive Energy Moderate, pulling Straasful, shearing of product surface when in use K of asbestos yarn through asphalt bath Control Heaaure(a) : Engineering controls, personal protective clothing, work practices ' None Measured Fiber Assumed to be less than Concentrations (f/ca-*): 2 f/cm-* within workroom environment No data presented, beyond scope of study Environmental Setting: Indoors, open room of factory Activity of Concern Raaoval of worn friction aaterial. Materiel enclosed in machinery housing. Installation or removal may occur indoora or outdoors. TEXTILES REFERENCES 1. Sores, Inc. and Arthur D. Little, Inc. Characterization of the U.S Textile Markets. Ministere De L'Industrie Et Du Commerce, Government Du Quebec. Final Draft Report. May 1976. 2. Krusell, N. and D. Cog ley. Asbestos Substitute Performance Analysis. Revised Final Report. Prepared by GCA/Technology Division for U.S. Environmental Protection Agency, Office of Toxic Substances, Washington, D.C. February 1982. 3. Anon. Handbook of Asbestos Textiles. American Textile Institute. 3rd Edition. 1967. 4. Scott, S. W. Produce Asbestos Yarn, Safely. Textile World. 131:69. March 1981. 5. Southern Textile Corporation. Our Colorful World of Industrial Textiles. Brochure Ho. SA-8456 Rev. 79. Charlotte, N.C. 1979. 6. Garlock, Inc. Mechanical Packing Division, Industrial Packing Brochures. Palmyra, NY. 1979. 7. Amatex Corporation. Textile Product Brochure, 10-79-SM, Norristown, PA. 1979. 8. Telecon. William Maaskant, Sales Manager, Amatex Corporation, Norristown, PA, with Peter Anderson, GCA/Technology Division, March 23, 1982. 9. Telecon. Michael Howie, Product Manager, Southern Textiles Corporation, Charlotte, NC, with Peter Anderson, GCA/Technology Division, March 18, 1982. 10. Derricott, R. The Use of Asbestos and Asbestos-Free Substitutes in Buildings. In: Asbestos, Volume I, Properties, Applications, and Hazards. L. Michaels and S. S. Chissick, eds. John Wiley & Sons, New York, NY. 1979. . * - 11. Telecon.- Dewy Flint, Sales Representative, A. W. Chesterton Company, Stoneham, MA, with Peter Anderson, GCA/Technology Division, March 24, 1982. 67 12. Telecon- Larry DeFranc Corporation, Nashville, -president of Corporate vetopato:. Division, February 27, T1oJ nv WCh Thomas Anderson, CCA/Techr.Alogy' 13. r .S , Hicco Refraail Insulation, Application Bulletin R-5, Hicco Materials Division, Subsidiary of Armco Steel Corporation, Middlecown, OH. 14. Telecon. Edward Silvia, Sales Representative, Frederickseal, Inc., Bedford, NH, with Peter Anderson, GCA/Technology Division, March 18, 1982 15. Michaels, L. and S. S. Chissick, ed. Asbestos: Properties, Applications, and Hazards. Volume 1. John Wiley and Sons, Hew York, N.Y. 1979. p. 305-367. 16. Sores, Inc. and Arthur D. Little, Inc. Characterization of Che U.S. Textile Markets. Ministre De L'Industrie Et Du Commerce, Govemeaent Du Quebec. Final Draft Report. May 1976. 17. Levine, R.J. (ed.) Asbestos: An Information Source. Department of Health, Education, and Welfare, Publication Number (NIH) 79-1681. May 1978. 18. Schneider, T. Asbestos Dust Levels During Work with Cloths Made from Liquid Dispersed Chrysotile. Ann. Occup. Hyg. 15:425. 1972. 19. Gibbs, G. W. Fibre Release from Asbestos Garments. Ann. Occup. Hyg. 18:143. 1975. 20. Lumley, K. P. S. Asbestos Dust Levels Inside Firefighting Helmets with Chrysotile Asbestos Covers. Ann. Occup. Hyg. 14:285. 1971. 21. Samini, B. S. and A. M. Williams. Occupational Exposure to Asbestos Fibers Resulting from the Use of Asbestos Gloves. Am. Ind. Hyg. Assoc. J. 42:870-875. 1981. 22. Wright, M.D. et al. Asbestos Dust Technological Feasibility Assessment and Economic Impact Analysis of the Proposed Federal Occupational Standard: Part I. U.S. Department of Labor. Occupational Safety and Health Administration. Washington, D.C. September 1978. Draft Report.' 68 SECTION 6 GASKETS AND PACKINGS INTRODUCTION Gaskets and packings are found in virtually every mechanical, chemical, and thermal piece of process equipment where fluids are involved. Gaskets and packings are primarily used to prevent leakage between two bearing surfaces: gaskets for static applications and packings for dynamic uses. Gaskets are needed to obtain tight nonleaking connections between pipe flanges and other joints such as the covers and openings on all types of industrial and commercial equipment. Packing is used as a dynamic seal for revolving or moving parts, preventing leakage of the contained fluid along the bearing surface. Asbestos fibers have been used successfully in both product types because of their unique combination of qualities. In addition to providing heat resistance, resilience, and strength, the mineral fibers are also relatively chemically inert, which is an important factor for many of the gasket and packing applications. Gaskets Asbestos-containing gaskets are made from either compressed sheet, beater-add paper, or millboard. Beater-add paper and millboard gaskets are discussed in Section 1 of this report under Paper Products. Gaskets made from compressed sheet are used in pumps, compressors, valves, pipe flanges, industrial and marine engines, gear and axle housings, sheet metal covers, shim gaskets, industrial transmissions, and transformers. Because of the strength, chemical inertness, and heat resistance properties of asbestos fibers, the gasket material is used in applications where temperature, pressure, and fluid environments are extremely destructive. Compressed sheet has a higher density and lower polymer-content chan beater-add paper and millboard, hence it is used in more severe environments. The compressed sheet used to make gaskets is formed in a sheeting machine by rolling out a mixture of asbestos, binder, and solvent. The calendered sheet is then cut to size and packaged for shipment. Sheet manufacturing* may be a wet or dry process depending on product requirements. Compressed sheet formulations vary with manufacturer and product grade. A commercial grade gasket sheet, used in applications up to 204*C (400aF), contains 75 to 80 percent asbestos, normally chryaotile, whereas specialty grade gasket sheet, used in higher temperature applications, may contain as much as 100 percent asbestos, including chrysotile and crocidolite fibers. 69 Compressed sheet may be fabricated into gaskets at the primary raanufsecuring plant or more commonly sold to secondary procs:jra or distributors who supply the industrial equipment maintenance mt :ket. Packings Asbestos packing is a braided product manufactured from untreated asbestos yarn. The y a m is purchased from a primary manufacturer and made into the sealant material by a packiag fabricator. The asbestos content in packing varies considerably, and may be as high as 100 percent for high temperature applications such as sealing furnace doors.* Braiding is performed using a flat belt common shaft electric driven machine or other similar equipment. The y a m used is untreated because resin impregnated or similarly coated y a m will not pass freely through the braiding machines.^ After the y a m has been braided, the newly formed packing material may be packaged as is, uncoated, or, more commonly, saturated with a lubricant. Dry, unlubricated asbestos packings are used to seal furnace doors, rotary kilns, and high-temperature refractory equipment.^ Lubricated asbestos packings are employed in a variety of industrial, commercial, and residential equipment applications, as well as in motor vehicles. Saturation of the braided material is accomplished by passing the packing through a heated liquid bath that contains the lubricant. Some of the more common lubricants used in packing manufacture are:^*^ petroleum based oils and waxes, high grade animal fats and waxes, Teflon, mineral oil, natural rubber, Buna-S rubber, vegetable oil, glycerine, graphite, and molybdenum disulfide. This treatment process is performed to maintain product pliability while in aervice, to retard material desiccation, and to prevent the abrasive asbestos fibers from scoring machinery shafts and valve sterna during use.^ Final processing before packaging for sale, involves calendering the packing material into specific sires and cross-sectional s h a p e s . C o m m o n cross-sectional shapes are round and square. Square packings are preferred because they provide a good seal, creating no gaps along the packing/shaft or valve stem interface. SECONDARY PROCESSING-- FABRICATION Gaskets' into aSecondary useable processing, which involves transforming the compressed sheet gasket product, is performed by an independent fabricator or the maintenance user. Fabricators, such as gasket cutters, generally form 70 gaakeca from compressed sheets by die-cuCC itvg, while Che mainCer.ar.ee u.er cut. Che sheet manually (see End Use Activities subeeccion below). Ir.dependenc fabricacora, who cut Che sheeC Co cuaCoraer epee ificaCions, also supply uncut aheeC8 Co Che maintenance user who will field fabricate the mczerial to their own specifications. One secondary processor contacted, B and D Supply, Inc. of Yeadon, PA, estimated that marketing uncut gasket sheet accounted for less Chan 10 percent of their annual sheet sales. Gasket cutting by the secondary processor is normally performed by forcing a metal die through the compressed sheet using automatic or semiautomatic pressing machinery, which sometimes requires manual gasket sheet feeding.^" 11 The actual cutting process, when the die is forced through the gasket sheet, lasts only about 1 second, compared to up to a minute for product handling time. Because of the clean edge cut made and that asbestos fibers are firmly bound by the gasket matrix, the potential for fiber release during secondary processing is low. This explains, in part, why engineering dust control devices are not normally employed for the cutting operation and Che press equipment is open to the workroom environment. ^ Operators may wear gloves during material handling, which includes sheet feeding, product separation (hand-picking), and packaging.^ Packings Packing distributors^"^ report that, in contrast to gaskets, packing is infrequently cut before being supplied to the end user. This is due to the simplicity of the packing/cutting procedure, as well as to the variations of end use application. A representative of. Janos Industrial Insulation Corporation of Moonachie, N J ^ did indicate, however, that packings may be cut to length by a secondary processor for a specific type of application using automatic machinery equipped with a wet dust suppression system. Also, some distributors may mold packing, which does not involve material abrasion or severing, to a customer's specifications using an automatic p r e s s . For n0gc applications, however, direct distribution of the standard square.or round cross-section material is sufficient to perform job requirements. END USE ACTIVITIES Gaskets Compressed sheet gasket end use activities include installation,' in-service use, and removal during equipment maintenance or gasket replacement. Gasket installation normally involves temporarily securing (holding) the precut material to one bearing surface while carefully aligning the other surface over the gasket. When the gasket is in place between the two rigid surfaces, the joint is sealed by torquing down bolts or clamps *at regular intervals along the perimeter of the joint. In service, the gasket faces are isolated from fluids on either aide of the joint by the pressure of the bearing surfaces. Gasket edges, however, may be exposed on the internal or external side of the joint. For special applications, field fabrication may be required to obtain the correct gasket sire and shape. Gasket shaping can be performed with a sharp knife or scissors.^ After installation, the gasket's service life depends on the severity of work conditions and Che frequency of equipment maintenance. A common cause for gasket replacement results from disassembly of the joint f;r routine maintenance. The gasket may be damaged during disassembly or its sealing capability may be in doubt due to low compression. Rather than risk a leak by rinstallation of the used gasket, a new one will be inatalled in moat cases. * in 1978 it was estimated^ that 15 percent of the asbestoscontaining gasket materials* produced are used in new installations, 25 percent for replacement of gaskets failed within 1 year, and 60 percent for maintenance and long-time replacement. During removal, portions of a gasket may adhere to the bearing surfaces if high temperatures or penetration of working fluids altera the elastomeric' binder in the gasket matrix. The adhering material is typically removed . manually using a flat-edged scraping tool (e.g., putty knife, paint scraper, or screwdriver) or a stiff wire b r u s h . I n many cases the energy input must be well controlled to avoid damaging the joint surfaces, which must be smooth and level for a proper fit. The removal process lasts several minutes, whereas the overall maintenance Cask typically requires a half-hour or more. Penetration of the working fluid into the gasket material is expected to suppress fiber release during removal. To facilitate gasket release from bearing surfaces, some compressed sheet manufacturers offer materials covered with an anti-stick film. Packings Similar to gaskets, Che end use activities associated with packing applications include installation, in-service use, and removal. Packing installt ion varies depending on whether the process equipment to be serviced requires a dynamic or static seal. Pump and agitator shafts, hydraulic cylinders, and valve stems require a dynamic seal and are packed in a somewhat similar manner. These devices have a shaft that is in contact with process fluids in the interior of Che pump, valve, or vessel. Where the shaft exits Che device it must be sealed to prevent or control leakage of process fluids. The shaft exits these devices through a cylindrical cavity commonly referred to as a "stuffing box." The annular apace between the shaft and stuffing box is filled with packing material to control leakage. The packing is sized to fill this cavity by forming it into rings. Rings are formed by wrapping Che packing around the shaft and cutting with a knife.2Q2^ Packing rings may be coated with oil or grease before pushing them aloog the shaft and into the scuffing box. Most applications require from 4 to 10 rings seated back-to-back in the stuffing box.2^*2^ When in place, the packings bear against the inner (static) surface of the stuffing box and the outer (dynamic), surface of the shaft. Packings are held in place in the stuffing box by the "gland," a metal cylinder with a lip that ia tightened against the stuffing box. In a pump or agitator, the gland is tightened (pressing against the *Meylan's estimate includes compressed sheet, beater-add paper, and millboard gaskets. The latter two are addressed in Section 7. 72  . r U l in . c u f f u , bo>) o,, h process fluid between the pecking end the roc.ci '!h..r required Co provide lubrication to Che packing.20, 2 1 c* Packings used in static applications Co seal process equipment doors covers typically include twisted, braided, and plaited ropes as well as square a or rectangular composites.2122 pressing them into performed, These milled materials groove or are held in place by recess in the door or cover plate. The packing is usually cut to length using or cover static application, the packing functions a a sharp knife. In a door in a manner similar to gasket in that adjoining surfaces are stationary. Door and cover packings are usually unlubricated, although a rubber cement or elastomer may be used to help hold the material in place during installation.21 In service, dynamic packings may fail for a number of reasons. Failures are frequently related to improper size selection (thickness or crosssectional shape) or installation (cut length), worn or misaligned shaft or stuffing box, insufficient lubrication, or improper gland tightening. Packing failure may also result from loss of flexibility, chemical attack, or lubricant boil-off.221 The service life of dynamic packing material has been estimated to be less than 1 year for 90 percent of the packing applications, while the rest wear out much more rapidly.^ Failure of process equipment door or cover packings is usually related to alignment or compaction, since there is little wear on the material surface (no movement) and these materials contain a high percentage of asbestos, capable of withstanding temperature and chemical extremes. When properly installed, the service life of static packings generally depends on two factors: (1) material reaction with the fluid or gases being contained by the packing, and (2) frequency of process equipment maintenance. 2 Chemical reactions with process fluids or gases may degrade the packing material causing failure of the seal and leakage. Maintenance, whether scheduled or nonscheduied, prematurely ahortens the service life of the packing by requiring replacement of the material that has been damaged when the seal is broken.1 2 Removal of worn out packing from a pump, valve, or hydraulic piston requires equipment disassembly, followed by removal of the 'gland' (when present) and extraction of the material from the stuffing box using screw-tipped or pointed rods.221 Depending on how well lodged they are in the stuffing box, the packing rings may be torn during removal. Removal of a static packing from a door or cover is somewhat easier because of better access. Under these conditions the material is easily peeled off the door or cover plate or pried out of a retaining groove with a sharp object. The removal and subsequent installation of dynamic or static packing material may last from one-half hour to more than an hour depending on the size of the equipment and ease of access. The majority of the time spent during servicing is in disassembly and reassembly of the equipment. Material cutting will last only a few seconds and actual packing installation and removal will each require only a few minutes. Packing installation and removal operations are performed indoors or outdoors, wherever the equipment being serviced is located. 73 Fiber re Lease from Che handling and use of lubricated packings is expected to be very low. Packings, used in pumps, valves, and pistons, are impregnated or coated with a lubricant that suppresses dusting. CuCting operations performed during installation should cause minor or no dusting. Cuts must produce a clean, smooth edge in order to ensure good end closure when the packing is in place. In service and during removal asbestos fiber release is also expected to be low due to material saturation. Concerning fiber releasability from unlubricated packings used in static applications, Johns-Manville reports^ that where a door or cover is periodically opened or closed, the packing is decompressed and compressed, but without much abrasion. The potential for fiber release to the atmosphere is expected to be highest during removal of the unlubricated packing. The door/cover packings are generally twisted or woven to promote easy release from the sealing surface during u s e , ^ but prolonged compaction in a retaining groove, for example, may necessitate acraping when replacement is required. The packing material will be physically altered during this process, possibly releasing asbestos fibers. AIRBORNE FIBER MONITORING DATA Gaskets Secondary Processing - FabricationAirborne fiber monitoring data collected during the fabrication of compressed sheet into gaskets are presented in Table 16. Fiber concentrations for the processes monitored, which included machine cutting, harnf shaping, and various materials handling operations, ranged from less than 0.01 to 1.3 i / c w ? , with the exception of hand and machine punching operations that were performed without dust controls. Fiber concentrations measured for the uncontrolled hand and machine punching operations were 3.0 and 5.0 f/cm^, respectively. When control measures were applied to these two operations, fiber concentrations of less than or equal to 0.15 f/cm^ were recorded. End Use Activities-- Fiber monitoring data collected during the installation and removal of compressed, sheet gaskets are also presented in Table 16. Fiber concentrations measured during the performance of these end use activities were less than 0.4 f/cm^. The highest concentration recorded (0.39 f/cm^) occurred during gasket removal, which involved cleaning (hand acraping) adhering residue from a bearing surface. Airborne asbestos fiber release is not expected during gasket wear because the bearing surfaces are stationary during use. Packings -- Secondary Processing - Fabrication-- Because there ir virtually no secondary processing of packings, no * airborne fiber monitoring data were obtained. End Use Activities-- In April 1979, Johns-Manville conducted an airborne fiber monitoring study of routine packing installation, in-service use, and removal activities at their Manville, NJ p l a n t . ^ The simulated field operations were 74 TABLE 16 FIBER CONCENTRATIONS ASSOCIATED WITH VARIOUS COMPRESSED ASBESTOS SHEET CASKET HANDLING A C T I V I T I E S ^ .11.24 Study A c tiv ity performed A Punch r n n o p e ra tio n 4 I Power a b a a r o p e r a t io n Shear praaa operation touaeai praaa Picking operation Tunbling operation X atariale handling Platan praaa operation Platan praaa operation Meaaurcd fib e r coocentrationa (f/cu 3) bate of taata Duration of a c tiv ity / aaaapla t i n e ( in) A n a ly tic a l wethod 0.04 to 0.47 1980 0.17 1980 0.23 to 0.81 1980 0.04 to 0.08 1980 ` 0.10 to 0.31 1980 0.42 to 0.60 1980 0.11 to 0.34 1980 0.03 to 0.29 1980 0.03 to 0.13 1980 80 t o 211 188 30 t o 76 100 to 192 93 to 206 77 t o 141 91 t o 216 32 to 256 63 to 238 f ib e r ware counted by PCM* w i t h PLMb v e rifica tio n Pibara ware counted by PCM w i t h PLM v e rific a tio n Pibara were counted by PCM w i t h PLM v e rific a tio n Pibara were counted by PCM w i t h PLM v e rific a tio n Fibera ware counted by PCM w i th PLM v e rifica tio n P ib ara ware counted by PCM w i t h PLM v e rific a tio n P ib a ra wera counted by PCM w i t h PLM v e rific a tio n Pibara were counted by PCM w i t h PLM verification PCM (continued) Consenta Monitoring performed at a major gaaket fabricator located in Wiaconaio M onitoring performed at a major gaaket fabricator located in Wiaconaio M onitoring performed at a major gaaket fabricator located in Wiaconaio Monitoring performed at a major gaaket fabricator located in Wiaconaio M onitoring performed at a major gaaket fabricator located in Wiaconaio M onitoring performed at a major gaaket fabricator located in Witconain M oaitoring performed at a major gaaket fabricator lo c a t e d io Wiaconairi M onitoring performed at j major gaaket fabricator located in Wiaconain M onitoring performed at aa aabeacoa-uaing gaaket o p e ra tio n in Wiaconaio TABLE 16 (c o n tin u e d ) ( Duration of fib e r Dste a c tiv ity / coocentrationa of aample time Study A ctiv ity performed (f/cm 3) tests (min) A n a l y t ic a l method Coeaaeota H ydraulic beam preaa 1 Hand p i c k i n g and p a c k a g i n g 1 0.02 to 0.03 I960 61 to 178 0.06 to 0.20 1960 63 to 176 POf PCM M onitoring performed et ag aabeatoa-uaing gaaket operacioo in Uiaconain M o n it o rin g performed a t go aebeetoe-ueing gaaket operation in Uiaconain Platan preaa picking operator -0.09 to 0.12 I960 67 to 160 PCM H o n ito r in g performed at aa aabeatoa-uaing gaaket operation in Uiaconain le a v e a punch preaa o p e ra to r 0.12 1980 126 PCM H onitoring performed at aabeatoa-uaing gaaket o p e ra tio n in Wiaconaio C S t o r a g e f o r r e c e i p t and ieaua < 0 . 0 1 t o 0 . 0 3 1978 60 to 132 PCM Houaekeepingc par formed, k aaonitoring conducted a c t u a l work c o n d it i o a e ; 3 Sto ra g e f o r uaa < 0 .0 1 to 0.12 1978 97 to 122 PCM Ho c o n t r o l , * * n o n i t o r i a i j conducted under actugfg conditiona Hand punching ' 3.00 1976 N1 PCM No c o n t r o l , o o o i t o r i a jjl conducted under a c te i) conditiona Hand punching < 0 .0 3 to 0.13 1978 28 t o 31 PCM Uouaekeeping p a r ftM aaonitoring condeefij a c t u a l work condllM Hand o p a r a t a d mechanical punching < 0 .0 5 1978 30 PCM No c o n t r o l , a e a l i l conducted under'** work conditiona (continued) TABLE 16 (c o n tin u e d ) Measured Duration of i fib e r Date a c tiv ity / 1 A ctiv ity performed concent rat ion* (f/cm 1) of tat> aaaap l e t law (mio) A n a ly t ic a l method G o au ti Machina punching Machine punching Machine punching 5.0 1978 NR < 0 .0 ) to 0.7 1978 20 to 30 < 0 .0 ) to 0.06 1978 23 t o 31 Hand oh aping < 0.03 to 0.3 1978 7 t o 31 Machina abearing 0.5 to 1.3 1978 6 Machina shearing 0.03 to 0.15 1978 . 31 t o 38 Machina n ib b lin g < 0.08 to 0.A6 1978 8 Machina n ib b lin g 0.08 to 0.8 1978 26 t o 31 In stallatio n of flange gasket < 0.03 1978 30 PCM PCM PCM PCM PCM PCM PCM PCM PCM Mo c o n t r o l , m o n i t o r i n g conducted under actual work co n d itlo o a Housekeeping performed, m o n ito r in g co nd u cted under a c t u a l work co n d itio n # Housekeeping and v e n t i * le t ion, monitoring conducted under actual work c o n d it io n s Ho c o n t r o l , a o n i t o r i n g conducted under actual work co n d itio n * No c o n t r o l , monitoring Conducted under actual work conditions Housekeeping performed, m onitoring coaductad a c t u a l work condition* Ho c o n t r o l , monitorial; conducted uodar acta*!.) work cond ition s Housekeeping peri; mon itorin g coodeCfsA a c t u a l work cond ii' Ho c o n t r o l , moni, conducted wadaf work condition* (continuad) TABLE 16 (c o n tin u e d ) Study A c tiv ity performed Removal and co n cu rren t 1 in a ta lla tio n (b o ile r header gaekata) Clean-up follow ing removal by hand acraping Ramoval and hand acrap in g Heaaured f iber coocencrat ione (f/cm 3) Date of teata Duration of a c tiv ity / aample time (min) 0.02 to 0.3 1978 21 t o 93 < 0.03 1978 31 to 37 < 0 .0 6 to 0.19 1978 13 to 28 A n a ly t ic a l method PCM PCM PCM Removal and wire bruabing < 0 .0 3 to 0. IS 1978 23 to 33 POI Coamcnte Housekeeping performed, monitoring conducted under a c tu a l work c o o d ic io a a No c o n t r o l M o n i t o r i n g conducted under ectu el work c o a d it ione Ho c o n t r o l , m o n it o r in g conducted under actual work c o n d it io n * Housekeeping performed, m o n i t o r i n g co nd ucted under a c t u a l work co n d ition 'Fhaaa c o a tr a tt microscopy. bF o la ria a d l i g h t m icroscopy, thua rep orted f i b e r c o n c e n tr a ti o n s ara a l l assumed to aabaatoa f i b e r s . c Uoueekeeplng - hig h e f f i c i e n c y vacuum c l a a o a r a ware uead t o c l e a n a ra a a ( a r e a kept c l e a n and f r e e o f d a b r i a a c cu m u la tio n ), waate m aterial placed in aaalad coota Inara. dMo c o n t r o l no e p a c i f i c c o n t r o l a ware u s e d ; i . e . , no w e t t i n g , e n c l o a i n g , o r v e n t i l a t i o n , 'V e n tila tio n - filte r e d local exhaust v e n tila tio n provided to operation* HR - Hot R eported i I 1 performed on Cwo water circulating aide-by-aide pumps. An aria air sample between the pumpa and a aimultaneoualy collected personal aaaole were obtained. Both ends of each pump was packed with five rings of material, therefore 20 sections of packing were used per test. Six different dynamic packings were tested over a 4-day period. The duration of each test period was not reported. A minimum of four separate samples were taken for each packing tested: two (one area, one personal) during installation and use, and two during removal. The installation and removal operations performed were imilar to those described above in the End Use Activities subsection. Four of the packings tested were impregnated with petroleum-based lubricants, one was impregnated with a corrosion inhibitor and Created with a graphite surface finish, and one was rubber-coated and treated with graphite. No unlubricated or uncoated packings (e.g., used in static door/cover applications) were tested. Of the 28 samples collected, 5 had a fiber concentration* of 0.0 f/cm3, 10 had a concentration of "less than 0.1" f/cm3, 12 had a concentration of 0.1 f/em3 and one sample, an area sample taken during the removal of Che rubber-coated packing, had a measured concentration of 0.2 f/cm3. In general, the personal sample:-- revealed slightly higher fiber concentrations Chan Che area samples, and the installation/use activity samples showed slightly higher concentrations than the removal activity samples. SUMMARY OF FINDINGS Caskets Secondary processing of compressed sheet into gaskets can result in comparatively high workroom fiber concentrations, on the order of 3.0 to 5.0 f/cm3 during hand and machine punching, if control measures are not employed. When dust control procedures are implemented, which is usually the case, fiber concentrations resulting from various hand and machine processing steps and materials handling operations range from less than 0.01 to 1.3 f/cm3. Measured airborne fiber concentrations resulting from the installation of compressed sheet gaskets were less than 0.03 f/cm3 as reported by one study. Removal of these materials, however, can result in higher concentrations, up to 0.4 f/cm3 during hand scraping of worn material adhering to a bearing surface. In this latter case, fiber release is related to the physical exertion required to remove the material and to the high asbestos content (equal to or greater than 75 percent) of compressed sheet gasket. Table 17 summarizes the data presented in this section on compressed sheet gaskets and identifies the principal activities of concern with respect to asbestos fiber release. Phase contrast microscopy analysis assumed. 79 TABLE 17. SUMMARY OF COMPRESSED SHEET GASKET SECONDARY PROCESSING AND END USE ACTIVITIES o o h p d u cn C iik jta Secondary p roceed in g Kftd use A ctivity: Dle-'Cuttlng, packaging U tC a lU tlo a ; ia -sa rv ic a use;raaoval Duration: fa r Incident C utting: leaa than l sacood Packaging; up to I niouta In s ta lla tio n ; |-2 ninutaa Use: w a l l to y e a r s , depending on a p p lic a tio n I c a a v a li 5 to 20 n in u ta a , a qui penat disassem bly w i l l req u lro s e v e r a l n in u taa to nom than an bour D aily to ta l Cutting: aavaral ninutaa* Packaging: to ta l production tln a ovar 0 bour fork a h lf t Sana aa abovn Fiber te le a e a b llity i fh a a lta l Conpoaitlon Nodarata Asbeptoe fib e r co ataat f l to Biff in c o n a e r c ia l gradaa up to IOOS to r high temperature applicationa Hodarata Sana Pbyaical Conpoaltloa PI la b ia , nay bava a n t iatlck coating, uaualty "o ily " surface taatura Sana D isrupt!* Koargy Hydraulic praaa d le cu ttin g; aorting and packaging by hand Sanoval ; band ac rap lo g , band o r power to o l brushing to clean boaring aurfaca Control Haaaura(s); Otbar than ganaral housekeeping in volvin g vacuianing ibe procaaa araaa, no an g in aariog controls ara used. C e o a ra lly nona, though during removal op eratio n gaakat nay be sa tu ra te d w ith procaaa f lu ld a . fu rth e r fatting o f w o n n o t a r ia l p r io r to removel nay a la o ba perform ed. Maadurad F ib a r Concentrations (f/ c a * )l 0.1 to 1.3 with ganaral tousakaping 0.1 to 3.0 without control# 0.02 to 0.4 during in s t a lla t io n , in -s e r v ic e uaa and removal I n v lr o -- n ta l S o ttin g : Opaa roan, indoors Open roon, indoors o r o u tsid e A c t iv it ie s ot Concern Secondary fa b r ic a tio n , o a p a c ia lly d ie - c u ttin g ga a k e ta . Sod uaa, m novaI o f worn gaakata, p a r t ic u la r ly tba loaning ot adhering n o taria l iron barring aurfacaa* Packing a Secondary processing of asbestos-containing packings i3 ~ merally limited to molding operations, in which the material is pressed withcut material abrasion or severing. Any cutting of the packing is routinely performed by Che end user during installation, using hand tools. Installation of dynamic packings results in fiber releases on the order of 0.1 f/cm^. Dynamic packings are prelubricated and/or coated with friction reducers before use and further lubricated by process fluids during use. When dynamic packing material removal is required, the material is usually saturated with process fluid or still contains residual amounts of lubricant, both of which act to suppress fiber release. Removal is performed using hand tools requiring low energy inputs. Some material disintegration can be expected during the removal of severely worn packing. Airborne fiber concentrations equal to or less chan 0.2 t / c m r have been recorded during the removal of packing from a mechanical pump. Fiber monitoring studies documenting asbestos fiber release from unlubricated packings used for static applications have not been reported in the literature. Asbestos fiber release is expected from these types of packings during cutting, installation, and removal because they contain a high asbestos content, have a low binder content, and are not normally treated or coaced with any type of lubricant that would suppress fiber release. Table 18 summarizes the data presented on packings and identifies the principal activity of concern with respect to asbestos fiber release. 81 TA BLE 18 SUMMARY OF PACKING SECONDARY PROC ESSIN G AND END USE A C T IV IT IE S Product: Packings Secondary processing Cod UH A ctivity: t a r t ly performed, but may bo cut to len gth or itoldad In sta llatio n ( inclading cu ttin g ); in*service ; rta o u l D u ration : For Incident Cutting: leaa thee 1 second actu a l cu ttio g * Moldingi several nioutes (eat*) l o a t a l l e t i o a : 10" 20 o io u tea (C u ttin g : up to 1 o io u te a c tu a l)* Use: seeks to years* depending on a p p lic a tio n K e ssv a l; 10 t o )0 n i out e a D aily to ta l C u ttin g: se v e r a l o ln . Sana as above actual cutting Molding: t o ta llin g nora than l bour (ea t*) fiber talaaaab ility: Chemical Conpoaition Moderate f ib e r con tent up to to n (ra re ); vide v a r ia tio n in type and nout of lu brican t/ coatin g* depending on intended use* Low Sane; but dynanlc packing nay ba coatad w ith lu b ric a n t during i o a t a l 1 s t Ion , and nay ba aatu ratad w ith p rocase f lu id during ren ovel* S t a t ic packings w i l l ba u o lu b r lcatad* P h y sic a l Conpoaition F le x ib le , o i l y or wavy Sene su rfa c e then lu b ric a te d D isru p tive Koargy Cutting v itb e knifa or press nscblne* nolding In press Machines Knife or ebaare fo r cu ttin g during Installation pointed o r e c r e v - t i p e x t r a c to r to rnova dynenic pack* ing fro s tu ffin g bos* F lat-bladed knives to rnova a ta tic packings* Control Maasura(a): Wet suppression dust control during sutonstsd c u ttin g * Mo c o n tro l during nolding Mona Measured F iber Concentrations ( f/ c n 3)* Mo data reportad* work* room co n ce n tra tio n asauned to ba laaa than 2 f/cn 3 0*0 to 0*2 during tb s I n s ta lla tio n * ia ~ se rv lce usa and rn ovai o f lu b ric a te d and/or coated dynanlc packings* Mo d o te reported fo r u n lu b rlceted packings* Environm ental S e t tin g : Open roon* indoors Open roon Indoors o r outdoors A c tiv it y o f Concern As o val o f worn packings* e s p e c ia lly u n lu b rlce ta d n a t e r ia le used in a t a t i c ap p lica tio n s* GASKETS AND PACKINGS REFERENCES 1. Krusell, N., and D. Cogley. Asbestos Substitute Performance Analysis* Revised Final Report. Prepared by GCA/Technology Division for U.S. Environmental Protection Agency, Office of Pesticides and Toxic Substances, Washington, D.C. February 1982. 2. Product Brochure, "Gasketing Materials," Nicolet Inc., Ambler Division, Ambler, PA, January 1979. 3. Telecon. Betty Kallen, Sales Representative, Rogers Corp., Rogers, CT, with Marc Grant, GCA/Technology Division, March 23, 1982. 4. Meylan, W. M. et al. Chemical Market Input/Output Analysis of Selected Chemical Substances to Assess Sources of Environmental Contamination, Task III - Asbestos. Report prepared for U.S. Environmental Protection Agency, Washington, D.C., EPA Report No. EPA-560/6-78-005. August 1978. 5. Johns-Manville Corporation. Sealing Components, Comprehensive Guide to Mechanical Packings, Ropes and Tapes. PK-401. Ken-Caryl Ranch, Denver, CO. April 1978. 6. Telecon. Company Representative, Pepperell Braiding Company Inc., East Pepperell, MA, with Peter Anderson, GCA/Technology Division, March 18, 1982. 7. Telecon. Dewy Flint, Sales Representative, A. W, Chesterton Company, Stoneham, MA, with Peter Anderson, GCA/Technology Division, March 24, 1982. 8. Telecon. James Novello, Sales Representative, A. W. Chesterton Company, Stoneham, MA, with Peter Anderson, GCA/Technology Division, March 23, 1982. 9. Telecon. Cathleen Blake, Sales Representative, B&D Supply Inc., Yeadon, PA, with Marc Grant, GCA/Technology Division, March 18 and 25, 1982. 10. Liukonen, E. R. et al. Asbestos Exposure From Gasket Operations. Report prepared by Industrial Hygiene Branch, Naval Regional Medical Center, Bremerton, Washington, D.C. May 1978. 83 11. Hager Laboratories, Inc. Report on Service Number 3910, For Johns-Manville Corp., August 21, 1980. Published in HeaLth and Safety Facts: Mechanical Packings and Gasketing Materials Containing Asbestos Fibers, Johns-Manville Corp., Denver, CO. 12. Telecon. George Siegler, Sales Representative, Rhopac Inc., Skokie, IL, with Marc Grant, GCA/Technology Division, March 18, 1982. 13. Telecon. Emily Chris, Sales Representative, Arcy Manufacturing Co. Inc., New York, NY, with Marc Grant, GCA/Technology Division, March 18, 1982. 14. Telecon. Ernie Huber, Jr., Company Representative, Paramount Packing and Rubber, Baltimore, MD, with Marc Grant, GCA/technology Division, May 13, 1982. 13. Telecon. Thomas Connolly, Jr., Vice President, Janos Industrial Insulation Corp., Moonachie, NJ, with Marc Grant, GCA/Technology Division, May 14, 1982. 16. Telecon. Theodore Braun, General Manager, B&D Supply, Yeadon, PA, with Marc Grant, GCA/Technology Division, May 14, 1982. 17. Telecon. Patrick Yoder,. Sales Representative, Nicolet Inc., Ambler Division, Ambler, PA, with Marc Grant, GCA/Technology Division, March 26, 1982. 18. Product brochure, "Gasketing Materials," Colt Industries, Garlock Mechanical Packing Division, Palmyra, NY, August 1979. 19. Product brochure, "Sealing Components," Johns-Manville, Denver, CO, November 1979. 20. Product brochure. "Chesterton Sealing Devices," A. W. Chesterton Co., Stoneham, MA. March 1981. 21. Product brochure. "Comprehensive Guide to Mechanical Packings, Ropes, and Tapes," Johns-Manville Corp., Denver, 00. April 1978. 22. Product data sheets. "Palmetto Packings," Greene, Tweed & Co., North Wales, PA. Copyrights 1978, 1979. 23. Information brochure. "Mechanical Packings and Gasketing Materials Containing Asbestos Fiber," Johns-Manville Corp., Denver, CO. April 1981.24 24. Johns-Manville Corporation: Health, Safety, and Environment Department. Industrial Hygiene Survey Conducted July 1980 in Wisconsin. Results published in Health and Safety Pacts: Mechanical Packings and Gasketing Materials Containing Asbestos Fiber, Johns-Manville Corporation, Denver, CO. 84 SECTION 7 ASBESTOS PAPER PRODUCTS OVERVIEW Products within this category include those that contain asbestos fibers and are manufactured on a fourdrinier or cylinder paper-making machine. Several subcategories have been identified for Paper Products. For this report, the following subcategories were investigated; roofing felt, flooring felt, millboard and rollboard, beater-add paper used for gaskets, and electrical insulating paper. Paper product subcateg3 ties not profiled include commercial paper, specialty paper, and pipeline wrap. The manufacture of all asbestos-containing paper products is similar. Raw materials are blended together with water in a pulp beater or hollander. This base stock is then processed through a series of material build-up and dewatering steps followed by drying. Product differentiation results from the addition of a manufacturing step, such as the saturation of paper with asphalt to produce roofing felts, or from using different forming equipment, as with millboard production. Paper products are also differentiated by varying asbestos content and grades, as well as binders and fillers.^ ROOFING FELT Introduction Asbestos roofing felt is a paper product that is converted to a weather resistant roofing material by saturation of the paper with asphalt or tar. Asbestos fibers are used in the manufacture of roofing felts because they provide dimensional stability and resistance to rot, fire, and heat buildup. Rot resistance is particularly important due to roofing felt's use on flat or nearly flat surfaces having poor drainage. Asbestos roofing felts are typically composed of 85 to 87 percent asbestos (primarily chrysotile) with differing amounts of cellulose fibers and starch binders. Sheets of roofing paper are made, in either single or multilayered grades and may have fiberglass filaments or wire strands embedded between the felt layers for reinforcement. Following formation on the papermaking machines, the paper-like product is either drawn through a bath of hot asphalt or coal tar to provide a weather resistant coating or wound into rolls for future processing. The process of 85 *curt m g che felc wich asphalt is a distinct operation, often performed by che feic manufacturer ac a different plant from where the felt itself is made ^ Secondary Processing-- Fabrication There is no secondary processing of asbestos-containing roofing felts. These materials are supplied in roll form by the roofing felt manufacturer to local distributors who market roofing products to construction firms. End Use Activities Roofing felts are primarily used as one component of "built-up" horizontal roofing systems and less frequently as an underlay for inclined, roofs covered by conventional shingles or sheet roofing materials. Both applications require cutting the asbestos felt to size prior to attaching it to the roof deck using adhesives or nails. If removal of the roofing material is required, the methods used depend largely on the materials of construction and amounts installed. Built-up roofs are constructed by building up successive layers of roofing felt (asbestos or nonasbestos) and asphalt or an asphaltic-type coating. The felts used may be composed of asbestos fibers, fiberglass, or organic fibers, all saturated with asphalt.^*^ With respect to asphaltic roof coatings and cements, a vide range of product types are available. These include both asbestos-containing and nonasbestos-containing materials.**^ Three basic types of built-up roof systems are currently in use. They are smooth surface, gravel surface, and mineral surface. Each type includes a number of variations which allow for the use of different felt compositions, number of felt plies, and type of roofing substrate (nailable'deck 'without insulation, insulated,nailable or nonnailable deck, or light weight loosefill insulating material). The smooth-surface roof type consists of alternating layers of asphalt and roofing felt Copped with a light application of heated asphalt or a cold-apply asphaltic coating. The gravel-surface roof type has a similar built-up layer configuration but the top coat is a heavy application of heated asphalt, over which a mineral aggregate is distributed and embedded. The mineral surface roof type has the same built-up layer construction as the other two but the top covering consists of a preformed inorganic "cap sheet" mat that is embedded in a layer of asphalt. The cap sheet is manufactured in different colors and is installed to add a cosmetic finish to the roof. During installation roofing felts are cut to. length using a knife whereas width cuts, when necessary, are made using a knife or a "felt slitter" cutting tool.4 8 Felts, which are laid down with adjacent edges overlapping, are attached to the roof deck and to underlying felts using hails or asphalt^ depending on the deck composition and the roof slope. Asphalt may be mopped on and che felt-manually unrolled and pushed into the asphalt, or a specially designed machine can be used that automatically dispenses the asphalt and 86 at applies Che felt. In order to achieve a uniform membrane (referring Co Che total built-up layer) thickness along Che edges of the roof deck, a single felt is ordinarily cue lengthwise to obtain two felt strips of the required widths to build up the perimeter thickness. These strips are generally 30, 46, and 61 cm (12, 18, and 24 inches) wide. When the felt is used as underlayment for a shingle or sheet roof, the felt is generally nailed to the deck and no asphalt coatings are used.^ Asbestos roofing felts have been in use for over 100 years.^ Built-up roofs comprised of these felts are reported to have an expected service life of at least 20 years, with some lasting up to 40 years. Product deterioration results principally from climatic exposure. During weathering asphalt coatings and asphaltic felts become brittle and crack.^ Where isolated leaks occur due to excessive wear, the roof may be repaired simply by application of heated asphalt or a cold-apply roof coating to the affected area. If the deterioration is widespread, the entire roof must be recovered or replaced. Since the roof membrane derives much of its integrity from the structure of overlapping felts, a number of localized repairs is much less effective than total recovering or replacement.^ Industry representatives report that more than 60 percent of the asbestos roofing felt produced is applied during reroofing, with the remainder used in new construction.^ Johns-Manville representatives report that the smooth-surface type of roof is the easiest to recover and replace, owing to the smooth surface and overall light weight.*** A gravel-surface roof requires at least power-brooming to prepare the surface for recovering, and frequently the top layer of gravel/asphalt must be removed entirely to provide a smooth surface. > Additionally, the gravel-surface roof is the heaviest of the three built-up roof types, and careful attention must be paid to the structural capacity of the underlying roof deck if the existing asphalt flood coat and gravel are to be left intact. Recovering tends to be preferred over reroofing because of lower costs. Roof removal generally requires chopping or sawing the existing roof membrane into pieces which can be pried or scraped off the roof deck. Any number of roof layers may be removed depending on the scope of the roofing job, from the top layer of asphalt down to the insulation or the roof deck itself. Cutting tools commonly used are an axe or circular saw (mounted on wheels), the latter being faster and generally used on large jobs. *** The circular saw is preferred for removal of top layers of a membrane because it cuts to a controlled depth. After cutting, the cut-up blocks of roof are pried off of the deck or underlying layers with a shovel or crow bar. *11 In large job operations, the waste material is carted to the edge of the roof in wheelbarrows and is dropped down enclosed chutes leading to a ground-level dumpster. Less sophisticated disposal methods are used for smaller jobs. < * 1 A series of several scraping routines and a final sweep of the roof area may be necessary to prepare the deck for application of a new r o o f . 1 A Johns-Manville representative stated that it is impossible to characterize 87 the number of workers and time required for a reroofing job, as the work and even the tools used vary widely with the roof type.4 Removal of a 10.5 x 18 meter (35 x 60 foot) section of fiberglass-insulated asphalt rcjfing membrane, which was monitored by GCA/Technology Division personnel required about 2 h o u r s . ^ Built-up roof installation is in December 1979, estimated to take a similar length of time or longer to apply the multilayered membrane. Airborne asbestos fiber release during roofing felt installation is expected to be low. Asbestos-containing roofing felts, which are coated with asphalt, are quite pliable and normally carefully handled during built-uj> roof construction to ensure the integrity of the finished m e m b r a n e . D u r i n g installation, the only mechanical disruption applied to the felt is cutting with a sharp bladed tool. Liberation of asbestos fibers from such a low energy activity is expected to be minimal. In use, asbestos-containing felt is isolated from the atmosphere by layers of asphalt and/or other roof coating materials. Although these coatings may eventually wear off, wind and water erosion is believed to be a very gradual process whereby minimal fiber release is expected. By the time the felt becomes exposed, a membrane leak is likely and repairs would be performed on the affected area. Roofing materials tend to wear nonuniformly, therefore the felt is not likely to be exposed over the whole roof at one time Of all Che roofing felt end use activities, felt removal poses the greatest potential for fiber release. During this operation the top membrane coating and the asphalt in the felt have weathered to a hard, stiff material. During removal, when surface layers are sawed and scraped, the felt matrix is likely to be physically altered, releasing free-form asbestos fibers. The membrane top coat and asphalt coats between the felt layers, however, do tend to bind the cut felts together, minimizing felt fracture during prying and waste disposal. Airborne Fiber Monitoring Data Several monitoring studies have been conducted to determine airborne asbestos fiber concentrations encountered during roofing felt installation and removal. Results of these studies, conducted by the Johns-Manvilie Corporation and GCA/Technology Division, are presented in Table 19. Airborne fiber concentrations in and around the work sices were generally found to be equal to or less than 0.6 f/cva?. The Johns-Manville studies were initiated through requests by internal marketing staff or roofing representatives and spanned a period from October 1972 to August 1976, Air samples collected were analyzed in Waukegan, IL, Manville, NJ, and Denver, 00 by Johns-Manville technicians using the PCM analytical method.^ The CCA samples were obtained on December 11, 1979 and were analyzed by Eastern Analytical Laboratories of Burlington, MA using-SEM (500Qx) and EDXR techniques. The data presented in Table 19 do not indicate any trends as to which roofing operation has the greatest potential for airborne asbestos fiber release. Although reported fiber concentrations for any given study 88 * MD *> TABLE 19. FIBER MONITORING DATA FROM ASBESTOS ROOFING FELT STUDIES11'13 C M iU iau * lu f li > - Ms* A na S p e c ific p eril I ( a rt a eaapta* Teela/aaceriale fiW r lawat o / c 1) ' 10-10-11 (H O 1 Qiv. at H iK M iia ( ) ky l t M Ca. ( Q -- lw U lH U afi 11 2 J V 10-1J ( a ) 1 IckM t sc M i l t , U ( a ) ky Marie Ca. 2 ( I ) --Jla<-N iiy|lU (Mwk|s) 1 1 -1 4 -7 * ( * "! .* > a t I k I m , Ml (2 ,0 0 0 M <t> My M ei4eaclfi4 t M t n c t t r ( D - M u - M u y i t U (fiaavsr) 0 ? M ajerity a f e v t t ia c f a i t ; Caatvriaa kaaa, Ca* 1* 0 .1 a le e ip re4 ayMiti fiaiakiag fa lla AaiistaA c a t t l e aa* laws aa akava 0.2 tay la ( a l t C a rrie* f e t e s l a a p arattaes faaa aa akava 0.1 cava cmC( 1c Upvia* a f a p aratiaa -- 0.1 1 4lac lU r aparatiaa -- 0.1 1 Braarial a f aparetJee -- 0.1 4 I U f t akava aparat lee -- 0.1 Meppiac kat aapkalt m 0.1 Layiac a * c a t! lac ( i l l m 0.1 Cat aapkalt teak ep ere te r m 0.2 Oewawlal a f a p a ra tia a -- 0.1 a D ow iiai af aparatiaa (aaar 0 .4 aaa ekew tiap acrap a ff real ta tmefc) a Dowwlai a f ap aratiaa -- 0.1 CrwaA le v e l *00 f t ( te a eckeet ---- 0 .4 k u iU ia c O S f t kalaw real) a IS ft paIa* af aparatiaa* -- 0 .4 4 f t akava re ef a Saaa aa Ca* 1 area -- 0.2 4 1* ft ( a a r la f a f apara -- 0 .1 tia a , 1 f t akava real a >0-1* ft fM w ia f af -- 0 .2 a p a ra tia a * 1 f t akava roef Moppii^ ket aapkalt| is a r t a i f a ta ca t fa lt/C a a ta ria a 0 .0 fa it c a ttle **4 laylap kaaa* fftalakiap falta CMttlot aa* U f l 4 f a it I m aa akava . o .* t <0o aa co a iitio a a * V I 1-14 <10 ag i) Scavai at laiiaaag v la, O ( 1 .1 ) 0 ag f e ) *y S l a t i l i v a ria l a c l i g CD. <t> -- JatM -Heartlia (Vavtagaa) V II-) IM U U -w Iu ila *) N l. tiara I lla tM i, M (I.Mh ft) kf 1411 Macal a ! k * H Ca. I t , 1)-- Jataa-O arrtlla (M anilla) TABLE 19 (continued) ta .1 . i> Maa rea 1 ty a c llic ogaratiaa or a n cangiai foalsM atoriala lita r levai ( l/cm 'l* 1 I fe orviot of to il4iag oC g ra v a i la v a l 1 0-1 > I V ft 4avariai al 0.1 agorai loo, 4-1 fe atara eral 1 tama aa l a . 1 a ra * -- 0 .1 4 40 le agviai #1 agorailoa -- 0 .4 4 -1 fe ataca naal 1 * i 0.1 tavola Ca i w n tt f a c a j M M f a l a t a crick t r a am I m aa Ha. S a a c lama aa a t a r a 0.) I N war aawiag aa tamari a M a r aa, yry ta r 0.1 acclama a l a l t raaflag I tk M 4 ava aaw f a l l t a l l i i CaaCafiaa taaa f a l l 0.0 I fryiag a l l #14 ravf lag hry t a r 0 .0 Lay lag c m ( a l t ( a a r a llia g ) C aacarlaa ta a a fa te o.t tamar i ag 14 t i m tfkaalkarcmw 0.1 Yac k l a g a fait aitlag Caacarlaa taaa falC o.t Uyvia4 ca ra a r a l wart 0.1 a r r a -- raam raj - laaCallaCiaa 0.1 I ) I t 4avari a i a l mart 0.1 a ta a --ramarsi 0.1 I ) le 4 a v a ria i a l I ramai- 0.1 ta ra i ( n a l racaiviag aaata ravi i ag--pamarat - taaCallafiaa 1 )0 le 4ovari vO a l a r t ataa aa i at graaat la w l" " 0.1 *0.1 - laatallatiaa (cM tlatw i) TABLE 19 (continued) 91 CM -- M -- ) too -- V*JV 1* f")ta li poi tut V** I* (ft ii-- r il i ~ i* ( Tt Oft **4* ItM ; >J 1* ! *n 1 fill fIM I fUf* -F *J (1 I* > <*m 9 1 i t i rlM FT* <1 <i> ooo'lt) m `f i r t > TFH"i >!n o (** (i) -11-l (1*1 ta|l| fwv tapi I p n u l ) ft OR ^ m i l i t a lata! H H n t a . ft i (Ip m taylta Ipa^il) aiitpita untar. t | W M ta* 1 ( ft -- '*>* V M I* *r F"!4 c C"****> ft tua f fa tw| ( IH*** " W - ( D *!!* i#m n t >i ( " n <1 (i oot'i) a i~^i N ft -- * ri ) i f 1 (<) U-* <*!> yw tapia *0 aM p t p 4 4 i J t M M iia ^ n . | () l| taytaw ft wiip4ta untar. t 0*H*1* |mi h ta)Muuni*n* r* tn***# ft I** taj>|. .1 (pa fi* 11* ta f ll r* ta p ia l ft ft wpipnivi . (MIMI I-- " ta* | ft 'rai |1 M ! 1^0 ( ft (ripw) Mpnit - t (M W fW n H |iyj*w^*|aa4 au j* *aurr M R !& 1***1 viajata >fif>+4f -- itati ^' (taaf ( p a n u i q a o D ) 6 T 31ffVX TABLE 19 (continued) l( S 8 -.2 11 ~ -I I jtlj ml i*:Ji Itz t S VJ m l=.il _ ir:i : e ir2 . Is ii'K ; : .iz - 2 v;ii H ill] i i* I r r i i i # <* m1 i Z2 i: ] s J t2 ! t: t ti ti Wt-5 r. I ]m M * a--* H ii li * r : : a i 2 I 8 93 cutting, scraping, and sawing operations as compared to spreading asphalt or unrolling felts, the differences in fiber levels within a giver, study are leas than the differences between studies (generally less than 0.2 i/cm3) . The variations in reported concentrations between studies in which similar materials and operations were used seem to suggest some contribution from the work practices of individual roofers' or from background fiber concentrationa. A confusing factor in A of the 11 studies was that upwind fiber concentrations were higher than downwind concentrations, and in 3 of the 4 studies they were higher than work site levels. No explanation is given for these unexpected results. Summary of Findings There is no secondary processing of asbestos-containing roofing felt. The manufactured material is sold directly or through distributors to the roofing contractor. Asbestos-containing felts are used predominantly in "built-up" roof systems which combine the felts between layers of asphalt or other coatings. These systems are rarely used for residential roofing. The flat or gently sloping "built-up" roof is widely employed on commercial and industrial buildings. Asbestos-containing felts are occasionally used as an underlay for shingle or sheet roofing materials on inclined surfaces. Felt handling practices employed by roofing contractors tend to be fairly standardized, although a wide range of combinations with asphalt, roof deck insulation, and other felts occur. Felt installation is generally a low energy intensity process, requiring only felt unrolling, "brooming" (removal . of underlying air pockets), and mopping with hot asphalt. Only a minor amount of cutting (with a sharp-bladed hand tool) is required. Removal of existing roof material requires greater energy input. Power saws or axes are used to cut the substrate into 0.6 meter (two foot) square or larger blocks, which are then pried off and scraped from the underlying deck using crow bars and shovels. Despite the variety of cutting and scraping operations that are performed, roofing felts appear to have a low fiber release potential. This probably results from the encapsulation of the fibers during the asphalt saturation step of manufacturing. Also, during installation, as the felts are successively layered with hot asphalt and/or cold coatings, the asbestos fibers are further isolated. In addition, roof weathering is very gradual and fiber release resulting from wind or rain erosion is expected to be minimal. The greatest potential for fiber release exists during roof removal when high-energy mechanical disruption is required to remove sections of felt from the roof deck. Fiber monitoring studies indicate that asbestos roofing felt installation and removal operations result in airborne fiber concentrations that are equal to or less than 0.6 f/cm3. Table 20 provides a summary of the data presented on asbestos roofing felts and identifies the principal activity of concern with respect to airborne asbestos fiber release. 94 TABLE 20. SUMMARY OF ASBESTOS ROOFING FELT SECONDARY PROCESSING AND END USE ACTIVITIES Product: Roofing Felt Secondary processing End use Activity': No secondary processing performed Installation; in-service use; and removal Duration-- per incident Daily total 1 Site-specific; Installation and removal highly variable with roof size and number of felt layers. Actual felt cutting time is estimated to last less than one hour. Fiber releaeability: Chemical composition Physical composition Disruptive energy Low Before asphalt saturation: 85 to 872 asbestos fiber content, remainder filler(t and binder!a) Pliable, with a tacky surface Knife or slitting machine during installation; axes, power saws, and hand scraping tools during removal Control measure(s): Measured fiber concentrations (f/cm^): None 0.0 to 0.6 (ranging from installation to removal) Environmental setting: , Outdoors Activity of Concern Removal (power sawing and scraping) of womout, brittle felts from roof deck.. itn i FLOORING FELT Inc roducc Log Flooring felts are used to provide a cushioning effect under floor coverings and to aid in aubflooring moisture control. Asbestos fibers are used in the manufacture of flooring felts to provide dimensional stability and resistance to heat and rot due to moisture. Asbestos-containing floor felts may be installed separately as an underlay for various floor coverings or more commonly fused to the back of sheet vinyl flooring. The vinyl sheet flooring product backed with asbestos-containing felt was discussed previously (see Section 3). Asbestos-containing flooring felts, which are formed on conventional paperraaking machines, are composed of approximately 85 percent asbestos and 15 percent latex binder. Chrysotile asbestos fibers are used, with grades 5 and 7 predominating. Currently, a styrene-butadiene latex binder is used in the manufacture of these felts. Asbestos-containing flooring felts sold separately are most often used in residential applications. Asbestos flooring felts are used as underlay for floor coverings that include vinyl tiles, sheet vinyl, and carpeting, or on concrete aubfloors where moisture problems may occur. The asbestos paper product helps to absorb the moisture and transfer the water to the walls. Use of the flooring felt by itself presently accounts for only a small percentage of all asbestos felt produced, as most of the material is combined with sheet vinyl flooring. It is reported, however, that this product distribution is shifting towards an increase in the use of the unfinished felt as a floor general covering underlayment. ^ Secondary Processing-- Fabrication As mentioned above, asbestos-containing flooring felts may be sold as an unfinished product that is used as a floor covering underlayment or it can be fused to the back of sheet vinyl flooring. No secondary processing is performed on the unfinished felt product. Rolls of the material are distributed directly from the primary manufacturer to wholesale outlets a n d . retailers. End Use Activities Although asbestos flooring felt is used primarily in residential settings, the installation and removal of the underlayment is usually . performed by professional contractors. Work practices are implemented to minimize fiber release. Felt end use activities include subfloor preparation, installation, in-service use, and removal. To insure proper installation, a clean, smooth and level subfloor surface is required. Subfloor preparation is similar to that described in Section 3 for Flooring Products and will not be repeated here. 96 Before Che flooring felt i j _ ., .. . ^ 18 laid down* che dimension- of Che room nd perimeter wall configurations are measured and recorded. Next che measurements and wall irregularities are transferred to che flo-ring felt, followed by cutting the specified size and edge shapes using scissors or razors. Flooring felt installation is similar to sheet vinyl installation whereby the entire contacting surface will be pasted to the subfloor, only the perimeter of che felt will be pasted, or no adhesive will be used such as in the put-down-quick (PDQ) method. In use, the felt is completely covered by a flooring product such that it is isolated from direct wear. Minimal fiber release is expected during the felt's service life. The process of removing flooring felt is very similar to that for sheet vinyl flooring backed with asbestos felt. For a description of the removal process refer to the discussion presented in Section 3 on sheet vinyl flooring. Airborne Fiber Monitoring Data Mo fiber monitoring data associated with the installation, use, and removal of asbestos flooring felt have been reported in the literature. Fiber concentrations resulting from these end use activities are expected to be very similar to those recorded for the installation, use, and removal of sheet vinyl flooring backed with asbestos felt. Fiber concentrations measured during the installation and removal of sheet vinyl flooring backed with asbestos felt were on the order of 1.0 f/cm^ and 0.48 f/cmd, respectively (see Section 3). When recommended work practices are not followed (dry scraping) during the removal of worn out sheet vinyl flooring, workroom fiber concentrations of 1.0 to 2.2 f/cm^ may result. Summary of Findings There is no secondary processing of asbestos-coataining Most of the flooring felt manufactured today is incorporated vinyl flooring product, although the popularity of using the as a floor covering underlayment is on the rise. flooring felts. into a sheet felt separately End use activities associated with felt applications that may result in asbestos fiber release include subfloor preparation, cutting dur-ng installation, and material removal. No fiber monitoring data have been reported to document fiber release during the performance of such activities. Fiber release data are available, however, for sheet vinyl flooring backed with asbestos felt, which is handled and applied under conditions that a r e very similar to those of the unfinished flooring felt. Fiber concentrations up to 1.0 and 0.48 f/cm^ were measured during the installation and removal of asbestos felt-backed sheet vinyl flooring, respectively. Table 21 summarizes the end use activities associated with asbestos flooring felts and identifies the principal activity of concern with respect to airborne asbestos fiber release. 97 TABLE 21. SUMMARY OF FLOORING FELT SECONDARY PROCESSING AND END USE ACTIVITIES Product: Flooring'Felt Secondary proceeding End uae Activity: * eecondery processing Installation; in-service use; and removal Duration-- per incident Daily total 1 Cutting during installation is somewhat continuous lasting iron 10 to 20 minutes. Removal and aubfloor preparation is estimated to last A to 8 hours. Fiber releaaability: Chemical composition Physical composition Disruptive energy Moderate 85X asbestos fiber content, remainder being latex Pliable, soft Binders, hand shears, scissors, or a knife during installation, sanding or scraping during removal Control measure(s): Wetting during removal* Measured fiber concentrations (f/cm3): No data, but expected to be similar to fiber release from asbestos felt-backed sheet vinyl flooring during installation and removal, (1.0 and 0.48 f/cm3, respectively)* Environmental setting: Indoors, closed room Activity of Concern Removal of residual felt adhering to subfloor when recoossended work practices are not followed. *When following recommended work practices. MILLBOARD AND ROLLBOARD Introduction Asbestos-containing millboard and rollboard are considered paper products because they are manufactured by a process similar to that used to make paper. In structure and texture, millboard and rollboard products resemble cardboard, with millboard more closely allied with the heavier paper grades. Millboard is manufactured in individual sheets, this being the only difference from the continuous sheet production of other asbestos-containing paper products. The individual sheets are formed on conventional papermaking equipment employing a technique whereby the desired sheet thickness is obtained by building up layers of fibers on a rotating cylinder mold. When the desired thickness is obtained, the cylinder is then momentarily stopped as workers cut the built-up layer of material lengthwise, removing one thick sheet of damp millboard. The wet millboard sheet, containing about 50 percent water, is then air-dried or placed in an autoclave or oven for rapid curing. Finished millboard usually contains 5 to 6 percent w a t e r . ^ Although rollboard differs from millboard in that it is thin enough to be rolled, both are usually sold in flat sheets. Millboard manufactured in the United States is produced in a standard 1.0 by 1.2 meter (42 x 48 inches) size sheet with thicknesses ranging from 0.79 mm to 1.9 cm (1/32 to 3/4 inch). Thicker sheets are produced by laminating sheets together. Rollboard is a lamination of two 0.4 cm (1/6 inch) thick or thinner sheets. Asbestos-containing millboard (and rollboard) is composed of,asbestos fibers (68 to 95 percent), binders (3 to 25 percent), and fillers. Chrysotile asbestos is the most common fiber type used, with grade 5 preferred.^ The binders may include starches, elastomers, or silicates. Millboard may also contain 5 to 40 percent portland cement and starch as the binder.^ Mineral wool, fiberglass, and cellulose are commonly used as fillers.^ Millboard is one of the moat versatile asbestos-containing products. Its numerous applications are listed in Table 22. A principal attribute that makes it so adaptable to varied uses is the way in which it can be manipulated during installation: millboard is easy to cut, can be punched into shape, can be by awet molded, number of and is compressible. secondary processors Unfabricated millboard may be purchased who install it or incorporate it into other products; wholesale distributors who supply the molten metals and glass i n d u s t r y a n d construction contractors for use as a building material1 . Rollboard may also be-uaed in similar applications, but is generally less suited to industrial settings where structural rigidity is a desirable feature. In both the molten metals and glass industries, transfer rollers comprised of asbestos-containing millboard are used to convey annealed or pickled steel or flat glass from one point in the manufacturing process to another. Millboard is also used as slip planes to insulate the silica furnace linings of induction furnaces. Ocher industrial uses include mats to place hot products on, sealings for holes and flues in roofs of furnaces, thermal 99 CONTAINING MILLBOARD AND SPECIFIC APPLICATIONS1 liner Application Imin* l r t a l Carierai In b o i l e r s , s s g a s k e t s , which nay be a e t a l r e i n f o r c e d , s i f l a a e and b e s t b a r r i e r s , as s l l p planas for furosca linings. In trantfsr r o l l e r s chat eoovey hot a a t e r l s l from one point la s manufacturing procaaa to anotbar. E le c tric a l Thermal p ro tectio n In large c i r c u i t breakera Appliance F l r e - p r o o f l n g a g e n t f o r c o e i s e r c l a l and hone s e c u r i t y b o x e s , s a f e s , and f i l e s Al uni nun P o u r in g trough co v e r and trou gh l i n e r Marine, hipyard, alrrraf t Foundry Steel M etallurgical Liner for container that catch es hoe metal from cutting operations Trough l i n e r end ir o n trough cover Backup In s u la tio n for furnace lin i n g Used between the h o t mandrel end che b e a r i n g sh e ll in molten b ab b itt operation Ceramic Low mesa k i l n c a r s d ata Ae I n s u l a t i o n In g l a s s tank cro w n s, m e l t e r , refin er, sidewalls, etc. Cmnerc l ai M e t a l - c l ad d oor* Becween o u t s i d e m e ta l and wood c o r e Office partitions Between metal s h e e ts , valued as a fire p ro o fin g and sound deadening m a t e r i a l . Very la r g e p o te n tia l market S o ld e r in g f i x t u r e s and olderIn* blocks Sp ark and g l a r e a h l c l d s In welding nhept Flrtprool wallboard Washer In e l e c t r i c a l apparatus Lining* for safe, drycleaning machines, incin e r a t o r s , h e a t e r rooms enrage paneling H e ild en tlsl L in in g* fa r hone s a f e s , s t o v e , h e a t e r s and e le c t r ic switch boxes Tent shields Stuve pipe rings Stove mats, tab le pad* Perfume rin g s for o i l lamps LOO r door g a s ke t s , and heat proCeccion w a l ls . Millboard i 8 al so used as gaskets f o r j oini ng pipes at i n d u s t r i a l p l a n t s and f o r a v a r i e t y of boiler applications. Commercial applications include heat or flame barrier shields for welding and soldering operations, office partitions, and fireproof wallboards. Millboard is also used as a filler for metal reinforced gaskets that are frequently used on small air-cooled engines such as lawnmowers. In residential settings, millboard is used as a flame or heat barrier in wood and coal burning stove installations. It is also used in the manufacture of prefabricated fireplaces. Residential uses extend to the linings of safes, stoves, heaters, and electrical switch boxes; stove pipe rings; stove mats; and table.pads. Secondary Processing-- Fabrication Most millboard and rollboard manufacturers market their unfinished products through one or more distributors. These distributors will either sell directly to the end user or to secondary processors who fabricate the millboard for specific end use applications. Fabricating operations performed during secondary processing range from die-cutting gaskets and rings to drilling, sawing, and shearing the millboard to produce various dimension construction materials. The following discussion pertains to the more common secondary processing operations performed by millboard and rollboard fabricators and gives specific examples. In the molten metals and glass industries, asbestos-coataining millboard is fabricated into rings that are slid along the circumferential axis of steel mandrels to make heat-resistant rollers used in conveyor lines.^ The millboard rings are assembled with the steel mandrel, such that the entire outer surface of the roller is comprised of the edges of the millboard diacs. Manufacture of the transfer roller is performed in two steps by separate fabricators. The steps involved are: (1) die-cutting the millboard rings followed by (2) mounting them onto a steel mandrel. During die-cutcing, the millboard sheets are fed by hand to an automatic punch press which forma the rings from the sheet using a metal die. The actual cutting action only lasts about one second but it is repeated hundreds of times throughout an 8-hour work shift. After the rings have been formed, they are packaged and distributed to a second fabricator who assembles the transfer rollers. The millboard rings are slipped onto the steel mandrel and press-fitted together between two end flanges. Transfer rollers range in length from 4 to 7 meters (13 to 24 feet) and may_ contain from 800 to 1000 rings each. To provide- a smooth outer . rolling surface contour, 0.64 cm (1/4 inch)of the assembled roller's outer diameter is ground off using a surface grinding operation. Depending on production demand, grinding will vary from a few hours per day to an entire work shift. 101 The p o t e n t i a l f o r f i b e r r e l e a s e and subsequent d i s p e r s a l dvring d ie - cuc t Lng is expected to be low given Che somewhat r i g i d com;a 5i t ion of the gasket m a t e r i a l and t ha t Che oper at io n r e s u l t s in a c l e a n edg; c : t and has v i r t u a l l y no dust p ro p e l l a n t f or ce s a s s o c i a t e d with i t . However, a g r e a t e r f i b e r r e l e a s e p o t e n t i a l is expected during s u r f a c e grinding due to m a t e r i a l s h ea r in g. Also, Che high speed r o t a t i o n of the grinding whsel w i l l propel dust generated by the o p e r a t i o n int o the workplace a i r i f not properly c o n t r o l l e d . Crinding machinery i s commonly equipped with high a i r v e l o c i t y , low a i r volume capt ur e hoods t h a t vent to a baghouse dust c o l l e c t i o n d e v i c e . Workers may a l s o wear dust c o n t r o l f ac e masks as they d e s i r e and building doors and windows may be l e f t open to provide n a t u r a l v e n t i l a t i o n in the w o r k p l a c e .2021 In general, the fabrication of millboard or rollboard into a final flame or heat barrier product is no longer routinely performed by a secondary processor but by the end user.22***22 Janos Industrial Insulation of Moonachie, NJ,2-3 a major fabricator of insulating materials, has discontinued millboard and rollboard operations because of the increasing cost of insurance for workers handling hazardous substances. B and 0 Supply, Inc. of Yeadon, P A ^ d iscontinued their fabricating operations citing the complications of operating and maintaining dust control equipment, and J and S Supply Corporation, of Long Island City, NY,2^ estimates that only 1 percent of their millboard throughput is cut to size, while the majority of it is marketed unprocessed to retail outlets (lumberyards, hardware stores). When they do fabricate, J and S Supply2^ cut their millboard products to customer specification using s bench-mounted electric circular saw equipped with a vacuum exhaust dust collection device. The saw is located in an enclosed room having no special ventilation system. Saw operators routinely wear surgical-type face masks when cutting the millboard. Actual sawing time lasts only a few seconds per cut; accumulated over the course of the workday, sawing totals several minutes. Due to the abrasive shearing and propellant forces associated with drilling and sawing operations, fiber release into the workplace is expected. The pulverizing action of these power tools breaks down the cohesive structure of the millboard, producing fine-size particles that can be expelled into the air by the high speed cutting bits and blades. Consequently, the fabricating operations need to be controlled, and generally are, to minimize fiber release into the workplace. End Use Activities The end use activities associated with millboard and rollboard products . include field fabrication, product installation, in-service use, and product removal. In industrial environments, field fabricating operations primarily include cutting, drilling, and wet molding. Cutting can be performed using a handsaw. However, considering the dimensions of a standard size sheet 1.0 by 1.2 meters (42 x 48 inches), it is much faster to use an electric circular aaw or to score the material with a knife, breaking it by hand. Scoring followed by snapping, whereby the board matrix is more cleanly sheared apart, has a comparatively low dust release potential. Power-operated saws create higher 102 vpi** du*C r e l e a s e p o t e n t i a l s , but may be used in c o nj un c ti o n with dust c o n t r o l equipment and p r o t e c t i v e c l o t h i n g , p a r t i c u l a r l y i f the u s er is a large i n d u s t r i a l plant with o th er s a f e t y concerns ( e . g . , s t e e l , g l a s s , and ceramic m a n u fa ct u re r s) . D r i l l i n g t o o l s used on millboard are g e n e r a l l y power-operated, hand-held de vi ce s t ha t may or may not be equipped with dust collection d e v i c e s . ^ Field fabrication of millboard for use in commercial or residential settings is similar to that for the industrial sector. However, fabricating tools equipped with dust collectic systems are not likely to be employed considering Che small scale size and infrequent occurrence of fabrication at the commercial/residential level. Handling of asbestos millboard may occur from once or twice a week for commercial operations to once in a lifetime for Che homeowner. Duration of the finishing operations will depend on the quantity of material to be worked. Commercial and residential operations may last up to 8 hours or only one hour or fraction thereof. Under either setting, workers will use conventional tools readily available to them. Cutting and drilling operations are performed using hand operated or power-assisted tools. 25,26 ^he acCuai time required to perform each activity varies from a few seconds to drill a single hole to several seconds to cut a staight or curved line using a power saw or longer with a hand saw. Because millboard is fairly easy to cut, hand tools, such as scoring knives can be used to fabricate the material. The potential for fiber release from Che use of such hand operated tools is expected to be low due to the minor surface abrasion imparted by these tools and the absence of strong propellant forces. Any dust Chat is generated tends to fall directly to the ground, not upwardly dispersed as can occur with the use of uncontrolled power saws. As a minimum, protective clothing, particularly surgical-type face masks, are likely to be worn by the safety-conscious user.*526 Asbestos millboard used as a heat or flame retardant barrier is commonly secured to support surfaces and frames using adhesives or mechanical fasteners, such as screws, bolts, and n ails.^ in addition, sections of millboard may be set in niece unsecured, between metal support frames as in the case of slip planes.*^ Adhesive bonding is unlikely where a board is to be removed regularly, as in a foundry trough or catch basin liners where no fasteners are used. Also, because of its low tensile strength and easily abraided surface, millboard is not installed in situations where it could come in contact with moving parts. In situations where the millboard surface is left exposed, beveling or sanding with subsequent surface coating is not expected given the low aesthetic concerns in an industrial setting. Millboard installation time will range from days for new installations and renovations to a few hours for small material replacement jobs." If the millboard has been prefabricated, fiber release during installation is not expected. If field fabrication is required, the finishing operations wou-ld be similar to those described above. This latter situation occurs when mechanical fastening is required. Pilot holes will be drilled to avoid fracturing the millboard during installation. The potential for airborne fiber release and extent of dispersion during cutting will depend on the type 103 tT '* * e o drilling cool used. As discussed above, power-assisted cools are more likely Co introduce fibrous dusc inCo Che workplace chan hand operated Cools. Under industrial settings, where these activities are most cotx:a, power-assisted tools are generally used. Millboard and rollboard can also be molded to nonplanar surfaces by dipping in water prior to application Because the millboard serves no structural purpose (only insulating), mechanical attachment to a surface or frame is unnecessary as long as the surface covering or frame restricts board movement. The time required to apply the millboard by this process varies depending on the amount of surface area to be covered. Installation times of a few hours are likely. The potential for fib*r release during application is greatly diminished by wetting of the board prior to installation. Once installed fiber release is not expected under normal conditions given that this is a static application and no surface abrasion should occur. During removal, the potential for fiber release will be considerable unless adequate control techniques (e.g., use of a wetting agent) are employed. In dry form, cutting of this material to remove it has the potential to generate substantial dusting. Millboard rings used in the rollers of conveyor lines in the molten metals and surfaces. glass industries A representative are subjected to repeated of Guardian Industries of contact with very Northville, MI, ^1 ha ot glass manufacturer, reports that there is no visible wear of the roller surface on a day-to-day basis, but that the edges of the glass slab eventually score the roller surface through repeated contact. When a production line is shut down for several weeks for routine maintenance, about every 5 to 7 years, the most worn rollers (typically one-third of the tot'. of 220) are removed and sent to Che roller assembler for replacement of the millboard rings. Gaskets made from millboard and rollboard are carefully installed to ensure proper sealing during use. Gasket wear resulting in fiber release is normally not a concern since the bearing surfaces are isolated and immoveable while in-service. During routine maintenance or scheduled gasket replacement, however, portions of a gasket may adhere to bearing surfaces if the binder component Of the gasket is decomposed by high temperatures or penetration of working fluids. The adhering material can be removed manually using a flat-edged scraping tool or a stiff wire brush. The removal process for any gasket generally lasts only minutes, while the maintenance task which necessitates gasket removal may range from several minutes to several hours. The potential for fiber release during material scraping or brushing will depend on the dryness of the gasket and the intensity of the physical energy applied to remove the material. The dryer the remaining material is and the. greater the f-orce applied to remove it, the greater the potential for fiber release. Gaskets penetrated by working fluids tend to be pliable allowing them to be more easily removed and are less likely to disintegrate than dried-out material during removal. 104 Airborne Fiber Monitoring Data Secondary Processing Fabrication-- Fiber monitoring data associated with millboard secondary processing operations have not been reported in the literature. A representative of Nicolet Industries of Ambler, PA,^ a fabricator of asbestos millboard, reported chat the capture efficiency of a baghouse serving their punch press operation is high enough thAt workers do not have to wear respirators to comply with the 2 t / c w r 8-hour TWA occupational exposure standard. With respect to assembling industrial transfer rollers, a representative of New Hudson Corporation, Verticarb Division, of New Hudson, MI, 0 reported that fiber concentrations in the workroom air where millboard rings are placed on steel mandrels approached 0.2 f/cm^. Details about the sampling location, specific activities performed, and analytical techniques used were not provided. End Use Activities-- Actual field fabrication monitoring data for millboard gasket use activities are scarce. In a controlled laboratory glove box test , ^ scoring and sawing of millboard resulted in measured fiber levels of 8.4 and 6.2 f/cm-*, respectively, as simulate material fastening, adetermined piece of by SEM (5000x)/EDXR analysis. To millboard was subjected to hammering for 10 minutes in the laboratory glove b o x . ^ The recorded fiber concentration was 1.4 f/cm.^ The glove box results are likely to be higher than those expected under actual field conditions. Fiber accumulation in the nonvencilated air space of the glove box chamber could account for the relatively high fiber concentrations recorded. In an industrial setting, field fabrication would be performed in a large open workspace with good ventilation or out of doors. In a commercial or residential setting, onsite fabrication would take place in a relatively small room, normally 3 by 4.5 meter (10 by 15 feet) or larger, in a garage, or out of doors. Greater fiber dispersion, resulting in lower airborne asbestos concentrations, is expected under actual conditions. Summary of Findings Millboard and rollboard are used in a wide range of industrial, commercial, and residential applications. These board products are used primarily to insulate equipment or building structures from high heat or direct flame contact. They generally function in a static mode where they are not physically abraided while in service. Millboard and rollboard have comparatively high asbestos fiber contents and low binder contents, suggesting high fiber release when mechanically disturbed. Although millboard tends to be somewhat rigid in the greater^ thicknesses, it is ftot strong enough to be used in load bearing applications. When impacted with only a moderate force, millboard will fracture. 105 Jt Fabricating operations performed by secondary processors. particularly saving and grinding using power Cools, generate substantial dust emissions. Because of this, processing equipment are well controlled, employing engineering practices to minimize fiber release. Field fabricating operationa performed by millboard and rollboard end users are generally not as well controlled. However, the tools used by the general consumer are not as energy intensive. Many of the tools used, such as hand saws and scoring knives, are manually operated. Power tools not equipped with dust collection systems will occasionally be used. Millboard retail suppliers may warn their customers of the hazards associated with dust generated by board fabrication, but this is not standard practice. Representative fiber monitoring data documenting the release of asbestos fibers during millboard and rollboard field fabrication, installation, and removal are not available. A laboratory study simulating these activities has been conducted, but the measured fiber concentrations, ranging from 1.4 to 8.4 f/cm3 for hammering, sawing, and scoring, are not likely to be representative of concentrations under actual field conditions. Table 23 summarizes the information presented on millboard and rollboard products and identifies the principal activities of concern that are likely to result in airborne asbestos fiber release. BEATER-ADO GASKETS Introduction Another asbestos-containing paper product used to make commercial and industrial gaskets is beater-add paper. Beater-add paper is named after its manufacturing process, in which an elastomeric binder and asbestos fibers are added to the product mix during the beater step of papermaking.^ The binder, which may include latex, natural rubber, synthetic rubber, or neoprene, accounts for 20 to 40 percent of the paper product. Selection of the binder depends on the end use application for the gasket paper. The remaining 60 to 80 percent of the paper composition is asbestos fiber, normally chrysotile asbestos. Beater-add paper is produced in sheet or sheet-roll form with thicknesses ranging from a few hundred micrometers up to about 1 cm. Gasket products are routinely installed to obtain tight, nonleaking connections in piping and other joints. Beater-add gaskets are used as sealing members in applications where chemical inertness, heat resistance, and resilient strength are important. The major user of this type of gasket is the automotive industry. 3 0 - 3 2 Beater-add gaskets are used in sealing oil pans and pumps, gear case covers, cylinder head covers, and intake and exhaust manifolds. Metal-sheathed beater-add paper is used in cylinder head and exhaust manifold gaskets.2931 In addition, beater-add. paper is used in other transport at ion applications in a similar role, as engine and drivetrain gaskets. Eurther, it is used in a variety of industrial and commercial equipment, including heat exchangers, boilers, furnaces, and pipe connections. The chemical industry uses the asbestos gaskets extensively for equipment connections because of the chemical inertness of asbestos. TABLE 23. SUMMARY OF MILLBOARD AND ROLLBOARD SECONDARY PROCESSING AND END USE ACTIVITIES Product; H i l l b o i r d and t o l l board Secondary processing End use Activity ! D ie -c u ttio g % powtr sawing, s u r f a c e g r in d in g , aana t rillin g Fower o r hand s a v i n g , s c o r i n g and snapping, d r i l l i n g , n a ilin g or screw ing, wet s o ld in i Duration-- par incident ( D ie -cu ttin g : leaa than 1 eec. S aw in g, g r i n d i n g , and d r i l l i n g ! Several eecond*. Sawing, scorin g, or d r i l l i n g ; aecoods; Nailing or screwing: sinuta* (ectlsated ). a few daily total J t o 30 s i m i l e * a c t u a l c u t t i n g (u tie e te d ) 1 to 10 siou tea to ta l c u ttin g tLee (e c tls a te d ) Vibar ra la a a a b ility : Chesical canpoaitlon High Aebaetoa content 68-93Z; binder* ioclud* atarebae, alaatonara, a illca ta e. High rhyalcal co^ oaition M illboard: generally in flex ible, friable t o ll board: generally easirigid, pliable, friable Sasa 107 D lcniptlv* energy E l e c t r i c and hyd raulic-po w ered bladae for cu ttin g ; e le c tric power eaw ln g , g r in d in g and d r illin g toola Same; a le o hand c c o rin g w i t h k n i f e , hand cawing, hand baaaaering and crew in g , hand s o ld in g Control H iiu r o ( i) i Baghouaea on automated equip ment; vacuum exhaust systems on i o m p o r ta b le power to o ls Vacuus acheuet c o lle c t io n cyatasa oo eon* p o rta b le power t o o l * . F ie ld fabricatin g operation* s o c tly performed uncontrolled. Maaaurd l i b a r c o n cen tra tio n* ( f / c s ^ ) i Data not read ily a vailab le, accuse workroue concentration* t a be l e e * than 2 f / e s * ta p racan tativ* data not a v a ila b le . Environmental t a t t i n g Indoors; open space or c l o s e d rooms Indoor*t open and c lo c a d (bacasentc, garage*) Outdoor*. roosc, A c tiv ity of Concern End u e a i f i e l d f a b r i c e t i o n in v o lv in g power cawing, eandlng and d r i l l i n g op a ra tlo n a w itho ut tha uaa o f duet c o l l e c t i o n d e v i c e * . Hand cawing and a c o r i n g a l e o . Secondary Processing-- Fabrication Although some primary manufacturers transform their paper sheet into final product form, most beater-add paper producers usually market their product uncut to secondary processors. Gasket fabricators cut the paper to customer specifications using a metal die in stamping or pressing machinery. Some gaskets are modified by adding wire insert reinforcements .or sheathing the-paper with metal foils, plastics, or c l o t h . ^ The cutting machinery used is automatic or semi-automatic, the latter requiring manual paper sheet feeding. Vorkera use gloves to facilitate product handling. The actual cutting process in which the die is forced through the gasket paper lasts only about 1 second, compared to up to a minute of product handling time (including separation and packaging).^3 Total accumulated cutting time over an 8-hour workday is estimated to be approximately one hour. Cutting operations are performed indoors in a typical machine shop setting. Because beater-add paper used to make gasket products is not brittle, but somewhat pliable, the potential for fiber release during die-cutting is expected to be low. Die-cutting using powerful press machines makes a clean edge cut, purposefully preventing unnecessary ripping and tearing of the beater-add paper., In addition, die-cutting is not a vigorous operation, one that would propel dust into the workroom air. Consequently special duat control devices or work practices are not normally employed for the die cutting o p e r a t i o n . ^ End Use Activitiea End use activities include installation, in-service use, and gasket removal. Some job site fabrication may be required for special applications. When this occurs, material alteration will be performed using a sharp knife or scissors and require only a few seconds of cutting. Beater-add gasket installation is very similar to the installation process described for compressed sheet gasket in Section 6. The procedure normally requires placing the precut gasket on one bearing surface and placing the other bearing surface over the gasket carefully to ensure proper alignment. When the gasket is in place between the two surfaces, the joint is sealed by torquing down bolts located at regular intervals along the perimeter of Che joint. In service, the gasket faces are isolated from fluids on either side of the joint by contact with Che bearing surfaces. The gasket edge may be exposed on either side of the joint. Again similar to compressed sheet gaskets, the functional life span of a beater-add gasket depends on the severity of wear, chemical conditions of the work environment, and maintenance practices. Since Che joint is typically immoveable, material wear is normally not a concern. A common cause for replacement is disassembly of the joint for 108 I routine maintenance# If the gasket is damaged during disassembly or if it is compressed Co the point where its sealing capability for future use is in doubt, Che gasket will be replaced. With respect to removal, portions of a beater-add gasket may adhere to a bearing surface if high temperatures or penetration of working fluids alter the elastomeric binder of the gasket matrix. Adhering material will be removed manually using a flat-edged scraping tool or a stiff wire brush. The removal process lasts only several minutes, while the overall maintenance task often requires an hour or more (as in automotive applications). Beater-add paper manufacturers do offer s line of materials covered with an anti-atick film to facilitate gasket release from the bearing surfaces.29,34 Abestos fibers are not expected to be released to the air during the installation of properly selected pre-cut gaskets. However, fibers may be released during field fabrication of material requiring alteration to fit special applications. The potential for fiber release will be minimized by the use of hand tools such as scissors and knives. These tools make clean edge cuts, generating only a small quantity of loose particles. In service, beater-add gaskets are held in stationary positions by two bearing surfaces. Under such conditions no fibers are expected to be released to the air. During removal of the beater-- add material, fibers may be released to the air if the gasket has dried out and the force applied to remove the material is excessive and vigorous. Gasket material adhering to bearing surfaces may easily disintegrate during removal if the binders within the material have decomposed or been structural altered vith use. Under these conditions the cohesiveness of the beater-add paper matrix has been substantially reduced to the point where fibers can be readily released with only minor disturbance. Airborne Fiber Monitoring Data No airborne fiber monitoring data have been reported for beater-add gasket secondary processing or end use activities. Beater-add gasket manufacturers** and secondary processors**^ interviewed report that fiber release during fabrication activities is expected to be low due to the relatively high (20 to 40T) percentage of binder in the beater-add paper and the type of machining (die-cutting) performed. Rogers Corporation of Rogers, CT,^ claims that there are fewer exposed fibers on the surface of beater-add paper than there are on compressed sheet gasket material (see Section 6). Also, die-cutting, which is the most common operation performed during secondary processing, is less likely to produce fiber release than, for example a saving type of cut, because the material is sheared rather than ripped apart. With respect to gasket end use activities, particularly automotive* applications in which beater-add paper is most often used, the gasket is frequently coated with or surrounded by oil or petroleum sealants, or sheathed in metal. These conditions impart a dust suppression effect such that fiber release during installation and removal should be effectively reduced. Fiber 109 release can be expected, however, during the initial stages of gasket handling when Che uncoated material is cut for special applications, and during the removal and cleaning of bearing surfaces of dried out residual gisket material Summary of Findings No monitoring data are available to document airborne asbestos fiber concentrations associated with secondary processing and end use activities performed on beater-add paper gaskets. During beater-add paper fabricating and gasket handling, installation, and use, the potential for fiber release is expected to be low as long as the elastomeric binder in which the asbestos fibers are contained remains unde.-curbed and functional. Once the binder dries out or is 'cooked out' the potential for fiber release increases during product handling. Fiber release is expected during removal if the material adhering to the supporting surfaces is dried out and sanding or dry scraping is performed. Table 24 summarizes the data presented on beater-add gaskets snd identifies the principal activity of concern with respect to asbestos fiber release. ELECTRICAL INSULATING PAPER Introduction Asbestos-containing paper used for electrical insulation is formed on conventional papermaking machines. Electrical insulating paper is produced in rolls, tapes, tubes, and sheets. Asbestos is used in the manufacture of electrical insulating papers because it exhibits excellent thermal and electrical resistance properties. Paper composition varies with intended application, but generally contains chrysotile asbestos and cellulose bound with latex polymers.^- Electrical insulating paper manufacturers use automatic slitters (for thin paper) and saws (for thicker materials) to cut the paper to specified product use sizes.37,38 Most of the paper produced tends to be a composite of asbestos paper laminated with a structural fiber. '9,40 offers greater strength and rigidity than the asbestos paper alone, and the presence of the backing material and thermosetting resin or adhesive tends to reduce the potential for fiber release during primary finishing and subsequent processing and handling. Secondary Processing-- Fabrication Asbestos-containing paper used for electrical insulating purposes is fabricated into tapes, spacers or washers, and electrical component boards by the primary manufacturer or secondary p r o c e s s o r s . P r i o r to being fabricated into a final product, electrical insulating paper is cut to __ required sizes using slitting and die-cutting machinery. Actual cutting time for these two operations will last only seconds per cut, but over the course of a day, accumulate to several minutes or even hours for large volume, well-automated production operations. 110 TABLE 24. SUMMARY OF BEATER-ADD CASKET SECONDARY PROCESSING AND END USE ACTIVITIES Produce: Beater-add Caaketa Secondary processing End uae Ill Activity: Duration-- Par incident Daily total Die-cutting Few seconda Several minutes up to more than one hour (eat.) for an 8-hour workday Installation (involving limited cutting); in service uae, removal Installation-- several minutes (5-10). In service-- days to years depending on application. Removal-- 15-20 minutes Fiber releasability: Chemical composition Physical composition Disruptive energy (tools) Asbestos content (60-80X), binder content (20 to 40Z). Pliable material Shear cutting with press machinery Same Same, with possible coating of petroleum* based compounds collected during in-service use Hand operated tools, scissors Control measure!s) None reported Possibly wetting during removal, otherwise none Measured fiber concentrations (f/cm3): No data reported, assume work- Ho data reported room airborne asbestos concen trations to be less than 2 f/cm3. Environmenta1 setting: Indoors, open room, machine shop conditions Indoors, in open room or outdoors Activity of Concern Removal of wornout, dry, brittle material adhering to joint surface by sanding or dry scraping. cutting of uncoated gasket material prior to installation. Also, field  Froduce' t bricacion using the insulating paper includes, for example, e-pe w inding and electrical component board assembling. Asbestos insulating tape is wound over wires and wire windings (e.g., transformer coils) to provide a heat resistant covering. ^ 7 * This process is normally performed by machines, but may be done by hand for special applications. In cable manufacture, the asbestos tape winding is covered with a plastic or rubber sheath to provide waterproofing and abrasion resistance. Board assembling activities include attaching electrical components using screws and adhesives, and installing the board itself in an appliance or fixture.^ All of the secondary processing activities occur in typical factory environments. Depending on production demand, processing of the electrical msulacion paper and its intermediates will run from a few hours per day up to full time production. The potential for fiber release during slitting and die-cutting is expected to be low. Both of these operations result in clean edge cuts that generate small amounts of loose particles. When an asbestos-containing laminate is fabricated, the slitter operation is controlled by vacuum hooding that vents to a fabric filter for dust collection. Spacers and washers are die-cut from asbestos papers and laminates. Board mounting details required to carry electrical components in small appliances may be die-cut from heavy papers or laminates. It could not be positively determined whether these die-cutting operations employ dust control equipment, though a representative of the Facile-Division of the Sun Chemical Corporation of Patterson, H.J.^0 indicated that some type of controls are used. The potential for fiber release during the processing of insulating paper into electrical components is expected to be low considering that a majority of paper is laminated with a structural fiber. The addition of the structural fiber will increase the coheaiveaess of the paper making it less susceptible Co teuring or cracking during processing. Fiber relesse from insulating paper that has not been strengthen may occur when it is wound around vires or cables, bending of the paper, causing internal tearing can result in cracks that could release fibers. End Use Activities There are essentially no end use activities performed on electrical insulating paper that would cause the release of asbestos fibers to the air. Asbestos-containing electrical insulating paper a incorporated into products that require very little handling or manipulation during end use. Many of these products are used- in stationary applications. Under such conditions, there is no physical disturbance to the paper that would cause the release of asbestos fibers. Only -hen the electrical component is damaged or needs repair is thete a potential for fiber release. The following conditions provide reasons why only a minimal amount of or no fiber release is expected from the use of eletrical cables, transformers, electrical appliances, and other products that contain asbestos insulating paper: 112 r 2. The electrical component* containing the paper tend to be fragile; breakage or abrasion of the attached paper product is not encouraged in normal use. 3. If minor structural or electrical failure occurs, repair, for example of a wire or cable, would involve exposing only a small amount of the insulation. The repair of a wire or cable containing asbestos paper is similar to the repair of a wire or cable containing asbestos textile tape (see Section 5 for discussion). 4. If major structural or electrical failure occurs, the whole electrical component or device is usually replaced rather than repaired. 5. Electric appliances with repairable components are typically designed for easy removal of these components without damage to insulating washers or boards. Airborne Fiber Monitoring Data Quin-T Corporation of Tilton, N.H. a manufacturer of asbestos electrical insulating paper products, has conducted fiber monitoring studies at a number of their own as well as other plants which fabricate electrical insulating paper products. Relevant results from these studies are presented in Table 25. It is not known whether dust control equipment or special work practices were instituted during monitoring of these activities. The operations monitored, including cutting mounting board, die-cutting, tape winding, board assembly, and packaging and shipping, were found to generate workplace fiber concentrations of less than 0.1 f/cm3. Paper slitting appears to present the greatest potential for airborne fiber release, with fiber concentrations of 0.53 f/cm3 measured in the vicinity of this process. One other concentration recorded by Quin-T that may have significance, but is not presented in Table 25, concerns a concentration of 12.3 f/cm3 measured during the use of a band saw machine.J/ This datum is not presented because a description of the type of material being cut was not provided and the sawing equipment used is not typically employed for product fabrication. Summary of Findings The end use applications of asbestos-containing electrical insulating paper are confined to the applications of the products manufactured by secondary processors. There are virtually no product applications that. require field fabrication or even removal of the asbestos-containing insulating paper itself. Fabrication by secondary processors generally results in fiber concentrations of less than 0.1 f/cm3 in the workplace 113 r TABLE 25. AIRBORNE FIBER CONCENTRATIONS RESULTING FROM ASBESTOS ELECTRICAL INSULATING PAPER AND BOARD FABRICATION AND INSTALLATION PROCESSES.37 Activity performed Slitting paper Cutting electrical mounting board Die-cutting board Packaging & shipping Tape winding ' Board assembling Measured fiber* concentration (f/cm3) 0.53 0.14 0.031 <0.033 < 0. 008 <0.005 0.097 <0.028 <0.009 0.075 0.038 <0.008 0.008 <0.007 <0.006 0. 008 Date of tests 7-12-78 7-10-78 NR 6-01-80 NR NR NR 6-01-80 NR NR 7-10-78 NR NR 11-14-79 12-17-79 NR Duration of activity (min) 42 120 90 21 90 141 298 25 156 74 180 90 90 103 108 165 *As determined by phase contrast microscopy. NR - No Reported. 114 c environment. The manufacture and fabrication of these products appears to be limited to a handful of companies, and usage has declined dramatically since Che promulgation of standards identifying the health concerns associated with asbestos exposure. Table 26 sumnarizes the secondary processing and end use activities performed on electrical insulating paper and identifies the principal activity of concern with respect to airborne asbestos fiber release. 115 c * t \ 116 TABLE 26. SUMMARY OF ELECTRICAL INSULATING PAPER SECONDARY PROCESSING AND END USE ACTIVITIES Product: e le c tr ic a l lo iw la tin t paper Secondary processing Cod u ia kcititp Slitting; die-cut tlog ; saving ; steadying or vinding Installation; lo-aervice use; removal Duratio-- par Incident Slitting-- Intermittent to cont inuous for automated oparatioa* Die-cut ting-- less tban | eecood Aaaembl tag-- seconds up to ainutti Winding-- coot iououa Installation-- (no direct handling of asbaatoa paper) In service-- month* to years, depending spplicatlon temovat-- less than one hour (eat.) for alectricot component 4.11; total Slitting-- total production time (up to 8-bour shift) Dle-cuttlng-- several minutes up to houra dapandlng production voluaa \ Assembling-- eeveral hours ribar releaeabllltyf Chemical composition Winding-- total production tin (up to S boar shift) Hodarata Asbaatoa fibara and calluloaa with latex binder Low Seme, but laminates have epoxy coatinga Kfilcal coapoaltioa Ranging fro fairly atiff to pllabla (m , M laalut. a n l.aa pllabl. Dltnipclv. <Mt|jr Dia-cuttlng press, saving, slitter Scr.v fa.t.ala, (InatallatIon) machine, acrav faetening Vacuum exhaust to fabric fil ter control device on alittlng and earning machinery Hone Haaaurad fiber concentrations (f/ca^)t Slitting-- 0.01 to 0.53 No data reported Dle-cuttlng -- 0.01 to 0.10 Assembling-- 0.01 i Winding-- 0.01 to 0.08 aolrooaaatal aattlogt Indoors, open vorkroom of factory A c tiv ity o f Coocar Secondary p rocessin g, tap s l i t t i n g op eratio n . Indoor er outdoor, cloaed room or open air apacn. ASBESTOS PAPER PRODUCTS REFERENCES 1. Krusell, N., and D. Cogley. Asbestos Substitute Performance Analysis. Revised Final Report. Prepared by GCA/Technology Division for the U.S. Environmental Protection Agency, Office of Pesticides and Toxic Substances, Washington, D.C. February 1982. 2. Wright, M. D. et al. Asbestos Dust Technological Feasibility Assessment and Economic Impact Analysis of the Proposed Federal Occupational Standard. Part I. U.S. Department of Labor, Occupational Safety and Health Administration, Washington, D.C. Draft Report. September 1978. } 3. Cogley, D. et al. Life Cycle of Asbestos in Commercial'and Industrial Use Including Estimates of Releases to Air, Water and Land. Final Inhouse Report. Prepared by GCA/Technology Division for U.S. Environmental Protection Agency, Office of Toxic Substances, Washington, D.C., February 1982. j 4. Telecon. Clint Ford, District Engineer, Johns-Manville Corporation, Englewood Cliffs, NJ, with Marc Grant, GCA/Technology Division, May 10, 1982. 5. Telecon. Clint Ford, District Engineer, Johns-Manvilie Corporation, Englewood Cliffs, NJ, with Marc Grant, GCA/Technology Division, May 12, >4 1982. 6. Telecon. James Reis, Director, Asbestos Policy, Johns-Manvilie Corporation, Denver, 00, with Marc Grant, GCA/Technology Division, May 4 and 17, 1982. 7. Manual for Built-Up Roof Systems. Johns-Manvilie, Ken-Caryl Ranch, Denver, 00. 1982. 8. Telecon. Walter Straub, District Engineer, Johns-Manville Corporation, Oakbrook, IL, with Marc Grant, GCA/Technology Division, April 30, 1982. ' 9. Asbestos Information Association/North America. Comments on Draft Final Report, Asbestos'Substitute Performance Analysis, prepared by GCA/ * Technology Division for U.S. Environmental Protection Agency, Office of Pesticides and Toxic Substances, Washington, D.C. September 30, 1981. 117 Rulemaking on Commercial and InduaCrial Use of Asbestos Fibers. EPA docket No. OTS--61005. February 1980. 11. Roy, N. et al. Asbestos Product Test Results, Draft Final Report, prepared by GCA/Technology Division for U.S. EPA, Office of Pesticides and Toxic Substances, Washington, D.C. February 1980. 12. Telecon. Walter Straub, District Engineer, Johns-Manvilie Corporation, Oakbrook, IL, with Peter Anderson, GCA/Technology Division, March 11, 1982. 13. Submission of test results in letter of May 11, 1982 from James Reis, Director, Asbestos Policy, Johns-Manville Corporation, Denver, CO, tn Marc Grant, GCA/Technology Division. 14. Telecon. Michael Schaum, Production Planning Manager, Congoleuo Industries, Cedarhurst, MD, with SRC, August 1979, as referenced in N. Krusell and D. Cogley, Asbestos Substitute Performance Analysis. Report Prepared by GCA/Technology Division for U.S. EPA, Office of Pesticides and Toxic Substances, Washington, D.C. February 1982. 15. Carton, R.J. Development Document for Effluent Limitations Guidelines and New Source Performance Standards for the Building, Construction and Paper Segment of the Asbestos Manufacturing Point Source Category. NTIS, PB-238-320. U.S. Environmental Protection Agency. February 1974. 16. Meylan, W. M . , P. H. Howard, and A. Hanchett. U.S. Asbestos Paper Industry and Substitutes for Asbestos Paper and Asbestos Brake Linings. Draft Report. SRC No. L1415-05, Syracuse Research Corporaton. Prepared for U.S. Environmental Protection Agency, Washington, D.C. September 1979. 17. Telecon. James Reis, Director, Asbestos Policy, Johns-Manville Corp., Denver, CO, with Marc Crant, GCA/Technology Division, March 29, 1982. 18. Telecon. W. Craig Wilson, Vice President, Nicolet/Ambler Division, Ambler, PA, with Marc Grant, GCA/Technology Division, March 30, 1982. 19. Telecon. Theodore Braun, General Manager, B&D Supply Inc., Yeadon, PA, with Marc Grant, GCA/Technology Division, March 20, 1982. 20. Telecon. Gary Hughes, General Manager, New Hudson Corp./Verticarb Division, New Hudson, MI, with Marc Grant, GCA/Technology Division, April 5, 1982. 21. Telecon. Albert- Czonka, Manager of Equipment Design, Materials Handling Section, Guardian Industries, Northville, MI, with Marc Grant, GCA/Technology Division, March 29, 1982. 118 r 24. Telecon. Michael Diamond, Vice President, J&S Supply Corp., Long Island City, NY, with Marc Grant, GCA/Technology Division, March 30, 1982. 25. Telecon. Company Representative, Boulter Plywood Corp., Somerville, MA, with Marc Grant, GCA/Technology Division, April 1, 1982. 26. Telecon. Company Representative, F. D. Sterritt Lumber Co., Cambridge, MA, wich Marc Grant, GCA/Technology Division, April 1, 1982. 27. Telecon. Calvin Cooley, Metallurgical Engineer, American Iron and Steel Institute, Washington, D.C., with Marc Grant, GCA/Technology Division, April 2, 1982. 28. Telecon. James Reis, Director, Asbestos Policy, Johns-Manvilie Corporation, Denver, 00, with Marc Grant, GCA/Technology Division, April 5, 1982. 29. Product brochure, "Gasketing Materials," Nicolet Inc., Ambler Division, Ambler, PA, January 1979. 30. Telecon. Dr. Paul Parker, Technical Director, Colonial Fiber Company, Division of Lydall Corp., Manchester, CT, with Marc Grant, GCA/Technology Division. March 23, 1982. 31. Telecon. Betty Kallen, Sales Representative, Rogers Corp., Rogers, CT, with Marc Grant, GCA/Technology Division, March 23, 1982. 32. Telecon. John Mayo, Environmental Engineer, Boise Cascade, Beaver Falls, NY, with Marc Grant, GCA/Technology Division, March 23, 1982. 33. Telecon. Cathleen Blake, Sales Representatave, B&D Supply Inc., Yeadon, PA, with Marc Grant, GCA/Technology Division, March 18, 1982. 34. Telecon. Patrick Yoder, Sales Representative, Nicolet Inc., Ambler Division, Ambler, PA, with Marc Grant, GCA/Technology Division, March 26, 1982. 35. Telecon. George Siegler, Sales Representative, Rhopac Inc., Skokie, IL, with Marc Crant, GCA/Technology Division, March 18, 1982. 36. Telecon. Emily Chris, Sales Representative, Arcy Manufacturing Company Inc., New York, NY, with Marc Grant, GCA/Technology Division, March 18, 1982. 119 38. Te leon. Brian Thomas, Engineer, Manning Paper Division, Hammermill Paper Co., Troy, N.Y., with Marc Grant, GCA/Technology Division, April 8, 1982. 39. Telecon. Charles Wilmore, Division Staff Executive of Insulating 1 Materials Division, National Electrical Manufacturing Association, Washington, D.C., with Marc Grant, GCA/Technology Division, April 12, 1982. 40. Telecon. Anthony Coiro, Safety Engineer, Facile Division, Sun Chemical j Corp., Patterson, NJ, with Marc Grant, GCA/Technology Division. April 12, 1982. ) ) 120. SECTION 8 CONCLUSION AND RECOMMENDATIONS CONCLUSION This study was conducted to profile secondary processing and end use activities routinely performed on certain asbestos-containing products and to provide an analysis of the potential for asbestos fiber release during the performance of such activities. Product category profiles presented.were developed to provide information necessary to identify candidate products to be tested under future monitoring programs sponsored by EPA. Products to be tested are those for which airborne asbestos fiber monitoring data are insufficient or nonexistent. Fiber concentration data presented were obtained from technical reports, trade journals, and interviews with government agencies and industry representatives. Table 27 lists each product category investigated and presents all monitoring data compiled for the products. Table 28 summarizes, by asbestos product type, the number of monitoring studies cited in this report. Many of the studies have been performed on products that are suspected to release high fiber concentrations based on their chemical and physical composition and how they are acted upon, or on products having widespread use. The quantity and quality of the monitoring data presented vary greatly between product categories and products within each category. Measured fiber concentrations also vary among tests performed on similar products. These latter variances are attributable to monitoring in a laboratory glove box versus monitoring in a well-ventilated room or out of doors; employing dust control measures during some tests but not during others; differences in sampling location and analytical techniques; and differences in product composition. Consequently, meaningful comparative analysis of the test results is restricted. Based on Che data compiled, a combination of the following three factors will affect fiber release from asbestos-containing products: chemical composition (asbestos and binder content), physical composition (structural integrity), and intensity of mechanical disruption applied during handling (field fabrication, installation, and removal). Dispersal of dust generated . during product handling depends on the magnitude of the propellant force created by the tools or method of operation used. Actual fiber release to the ambient air, however, is governed by the presence or absence of control equipment or recommended work practices and their effectiveness in minimizing fiber release at the point of contact during mechanical disruption. 121 TABLE 27. MEASURED AIRBORNE FIBER CONCENTRATIONS RESULTING FROM SECONDARY PROCESSING AND END USE PRODUCT TESTING ACTIVITIES 122 - product liU itM -tta u t atece detesta# fre^n cl rut .beat A e tlv ltf pr(ra4 D rill (cara te w ir la v O .M tm ( 0 .1 ) I n . ) Chick ( U t a h a .t D rillin g h ale. (1(1) tawing ( 1 1 .) H t i f i ) i ilV tltO I-C IM tt heart ( ( U t abaat) liw tag w ith a e iic ttla r ( c i r k U t kita4) taw inc, t r illin g , aat a c r a llin e ( a b ra saw) i Hcaawrat lib ar coucaa- tv a t ion ( f / c - 1) Data ( ta ita D u tatio t p i K tltU f/ aan ^lln . tlmm (m in) n a u tica l a itte C oaarsti te l i.) IM I S o . i.i IM I 4 < i.t> (. -1 1 .7 (1 0 .2 -K .l) IM I 1 * 1 .0 IM I i ( (. 0 .1 l*7 *-l)0 0 0 0 .0 l7t-IM 0 0 0 .0 4 l 7 f 11 0 .1 ) 17 ' 17 010(11 NaChot* ((IM /C D n)k OIDI NaChot (M N /con) MIOIO H t t t e (io t/io n ) OIOS H athot (liM /C D K ) M a aa c o n tra s t (aeeuned) phase co n tra st ( k u m 4 ) rhaaa canerace Hu m C M tn it T itio | ptrlorM d la l g l o a t t e a . Oa I f t i h - re > J -n 1 length counted, oven vteo analysed using SOI. Tat(g ftr lo r e c l ia i g le e t e a . Only f i h - a ra >3 *m 1 tngch counted H a whan a n a ly se d u sin g SEN. Eased on two r e p a t i - i tio n a (a glow t e a . Only l i t e r s >3 no in length counted, even when a n a ly sed u sin g SIM T estin g p er(ornad in 1 g lo v e t e a . Only f ib e ra >3 tin in len g th c o u n te d , v ea when a n a ly se d u sin g SEH. D r i l l wee equipped 2 w ith duet pickup shroud. Sew wee equipped i w ith duet pickup shroud th a t t o ta lly enclosed naeoory hied e. Sew wee equipped 7 w ith duet pickup ehroud th a t veoti-d to p M illIs k hipa f i l t e r e d vacuun cteen er. Power t o o l e ware 7 equipped u itb dust pickup shrouds th at veoted to a N iifisk MEM f i l t e r e d vacuun c la a e e r * (cmllml) TABLE 27 (c o n tin u e d ) . Aabnctoa product category Aebaetoe frod u ct A ctiv ity forforood Meacured f Bar cone* (ra tio (t/eo J> Doc o f tto Durat too o f a ctiv ity / a a a p lia tia a ( la) Aaaiyt ico l oatBod Cenavate ta l. iib a itB itm a t baci U M tlM t ) Corrugated Woe G rin d in g t o c o t eta efc o f |I io ay l i r *L 0 . t o G rinding to c o t M o tlo g j k ilo roof J1 mo MD Fkace cootroat Teatog ferlo ra ed 4 outdoor* oo jo B * t c . Aacuoed no duat co atro lc ocad. i flo o r l o f f roda c t ( u c M I a l 1too ri a . fa it* kick a n c o t rod under ?ieyl~acbeetee flo o r tlla Out Gwlm* 0 0 (0 . J) tt*i Iffl s 10911 Not Bod T cctiog ferfo m d io i giovo Boa. 3 10SN Method T cctiog frfoncd io i d u /io n ) giovo Boa. Ooty f l h - parar) ; re _S ^ c io l e c ^ t B cow oted, cva I m o - aoalyced uciog 90. Brook 0 11(1 i BIOfN Method Tactiog p * tlo n 4 io 1 giovo Boa. D rill 0 lf l i BOBU NotBod Tcctiog ferfonoed lo I giovo Boa. V lo o rlo g n o o v a l t r i f f log 0 .0 2 - 0 .1 mo us in /io n M onitoring ferfo n aed s ap t l l a a duriog cto a l floo rio g reoovai, tn cu ltc are ore in d icativ e of invnlc neerby tha v o rk fla cc tBao tbocn ectu ally eiferien ced by th v o r k e r . f l o o r i n g ro o o T o l By t . 1 -1.1 I f 20-1(21 20 fB aia co n tract Siou latcd ta ctio g io A laboratory cHaobr roM lolag 3*1. 7 a2.1 noter 1 v ith four Ir changac/br. B ell andar v i t i coarca fe fe r ucad. floo r tllo 0 .0 0 2 (a 0.M 1 I f 2 1)0 ta If PWaaa c o n t r a c t M onitoring occwrrad 1 in nn o f i i c n c a t t t n g ; thn oronc caoninad v e ra ' fbotocofylng roon and a caack abof. (ctHi<) 123 V. 124 . ia M ite i product category Fleering product* (CMtlMMi) 1 * TABLE 27 (c o n tin u e d ) I r U ito product k t i v l t p performed Measured fib er Comeen- V lt t l'iilt iU floo r til* Floor c o M r itl u i o U u a c i ; " M l 0.131 t . 0.1*1 D at. . ( teat# mt Pu ffing 0.00 i*? t . 0.0*1 C o u p let# rum ora! by n command*4 f r o c a ^ H t t l * D .M 2 to 0. 1*3 1*3* K a n ta lln tlo u ky n c u M o lit procedure* o.oai to 1*3* o .u r l a e t e l l a t i o a by rtcoM M odtf procedure* 0.092 to 0.1M 1*3* Old t i l # p r p # r# tio n f # r 0.0 onu In s ta lla tio n C o n p U ti r t n o v il by i ontHod tH at d e v ia te # f roo rncomanoded procodum # 0.113 t . 0.3*3 I n s t a l l a t i o n by recoumeoded procedure* 0 .M I t . 0. K * 1(3* 1*3* 1*3 1 (c h U m 4) D uration of .c iio tt? / M U t ion U l.l 11 t . 31 A ualyt icn l a t Hod 11 t . 30 123 t . 1M PVasa c t r . i t 220 t . 232 FHnno c o n t r a c t 111 t . 114 10 0 FHocn c o n t r a c t (1 FHaan c o o t r o a t Coeeeata .i. k t i r i l y oaa per- 1 formed on flo o r t i l * lo c a te d in pHoto- e opf im g roam nod nneb hop. A ctiv ity vac par* 3 formed on flo o r t i l e * locatnd in photo co p y in g roou and cnocH chop. T n a t i ^ uaa performed 3 in laundry rooa, poudnr roou, c lo s e t, nod h n llvay of a p riv a te bone. T ile e , precoeted 7 o itH a d h e s iv e . were in a ta lle d in laundry ro o u . powder roou. c l o e e t , cod Hnllvay o f a p r iv a te hone* T e a tii^ vaa p er- 7 formed in baaeueot aod a u a tl u t i l i t y roou o f p riv a te hone. Preparation include a e t r ip p lo g and dry noppiqg of old t i l e au rlace. Dry a cra p in g and aweeping occurred during removal. lelf-ad berin g til i 8 warn in a ta lle d follow in g ataodard work p roced u re*. Author* poatulate th at fib e r levele recorded reeulted during preceding remove! o p era tio n . TABLE 27 (c o n tin u e d ) AWUi prodwet et|or7 iik a t o a product A c tiv ity performed Measured fiber conceal trac ion (f/ cm J> Data at tta Duration of K tivity/ l u p i lag tine ( ta) Aatalyt ic l atbod Comment * iat. floor!** rn 4 a cu U q l- t H lM d o o r loiwal building tr a ffic ta 1910 m (coailw ri) tlu I7<r 1 1 * ' Coating wad luti OWat rlr* flo o rl* * becked with eebeetoe flo o r !* (U lu tillitln f a r t i* ! m o n i 4y n c o n t a d i i procedure#* Couplet riativai Ay recommended procedura Couplet removal Vy recommended procedura Coartata r a m a i Wear layer rwoowal Pry e c c e p ii of flooring fait Wot craping of floo rin g fa it 0.0 ta 1.02 0. 1*0 ta O.AOg 0. ta 0a402 0.049 to o.ioo 0.004 ta 0. 21 1.00 to j.ir 0.004 i7o*ifr 1070 1070 1070 1)70 1070 1070 44 ta 170 44 ta 01 t i l ta 111 74 ta 70 70 ta 7) 40 ta 4) )) fprwy-wppliwd aaphaltic roof coat Inge Ckitkaclt aephalt M afia* 0*001 to 1074 0. 1) 141 ta 4)1 1 1" " (CMtilMa*) Transmition Sampling occured at 9 alactro n micro* four cite in o ffice acari (TOO building containing 5,400 m* of vinlp- beato (cbyroetile) floo r t i ta. Wo beato fiber >1 wn in length uern observed. fbaaa contrae! In sta llatio n covered tt four dberiog od one oooadhering appi I t e t i on fh iia contract M ateriel removed 11 bed beo adbe red to ubftooringa M ateriel renevti bad 11 been adhered to ubflooring a Pfcaea cnntrt M ateriel removed bed ii not been adbe red to ubflooting. Ohaaa ceatraat M ateriel removed had n beco adhered to ubflooring. Material removed had n been adhered to ubf loori^ a Phase contract M ateriel removed had i i been adhered to aubflooring* flu ia contract (aaauM*) Percent weight of 11 aebeeto ae prayed ranged from 5.1 to 7. 7, a fte r curing 9. 7 to 1M percent aaboatoa*  liktatu froJact AWitoi pra4uet Ottd MllUtl (c m K * m 4) f tipkall-Mililm klltif realla. * liaii eoitiaia TABLE 27 (c o n tin u e d ) Activity porfonssd Measured liWr COOCPP** lull tl/c*) D.t. .1 tecta Duration at activity/ uylin. Km (.1.1 1 Analytical Mtbod Conuati T*.r-*ff Tear-off a M rtflaca (prT> lav application (apraf) 1 Ship coating hy aprap apptitaciM 0.01 to 0.3 l)H,ll!l 0.1 to 0.4 0.0 to 0.) 0.0 to 0. 1074 1014,1014 im,im, 1070 0.1 1*74 ML t m m 0 t. 11 Dip 4ock CMtli| Dp aprap frllcailna 0.0 to 0.1 1014 11 t. 11 Ooatia p i n lutiltn * 0.1 1074 11 aprap application PiDar |lata pipa KFG (ualrtl coating) 0.1 t. 0.4 1014 14 t. 11 luiMil (aaaiaH) Phone contract (aaauaai) (a..47 (IIMl) Phaee contract (...4> TDaaa contract (aaanul) Nitaat wight of aiDaiioa pr*;<4 vac M , altar curing 0.1 paicaot aabcatoa. Monitoring parloraci in Indiana. Monitoring perforwd is Penney Ivoola and Lndiaaa. Monitoring perforwd in tfiecoeeie, Colo** talO| and iadiaoa. Operator aprapiog outside and under a chip with aebeatoecontaiaing apoap roain. faccaot eetoetoe aa aprapad Oporator aprapiog dock with aa aabaatoa^coataiaing epoxy and coal tar niatura. One percent aebcetoe aa aprapad. Oparator praying iotorl or of 7.4, 13, and 30 ca disaster pipe with an aabastoa-coatsial^ (1 percent) epoxy and coal tar aieturo. Oporatora nunicored wire involvid in running automatic pray nachioa aod wiping maodrol. A |.4 parcaat aebaatoa cbonical roaiataat raain was aprap,,11.4. (CMtlMfj) *1*94*9 .IMI1M499934)*4)4i*tW*)*l|| )X111A l|)|A * 999/ 40* 1 * 0 * 4 Cl tU )pO plt| I O ) J ld () 10*9 _ j*d ( o ) { . y o ) u i * * i i )i X |o < | q i o p 9 ?*0 9 odfd * * |l 4 * q j| p *9 jo )0 ) (P *-- > ) n . i tU fA l* )01 J d Q > o f * j i * ) d |o d lo d in d ( i m | t o i * 9 q * * )o * o j 4 *o (P *-- ) Cl ta f l* 4 d * Jo ) i*d Q 1*941009 u r u > *l*f t o i * o q * 9 ) n j i d / *0 ( -- > Cl |p ] 4 t i d i i 9 i i i * d o U * A 1 *9 J U a no i l l ] fC ojA * o ]* * q * 9 1 o * u a 4 c t o> | ' I n I o]C i j 4 i l o i m d o 1 11 It t ! C 'O 0*0 * > *1 1*0 mi 1 W 'l it 1 * C /l `m i `u * i **0 0 `0 < > 1 * i l il mi mi 0 0 1*0 1 0*0 |M 4 f c |P || i ]IW 4 *l* ifo 4 1 1 ) 4 p * 1 9 0 3 4 )4 taT M 9f . 9 J N }* > l i l i l )W T | t a f 9 4 d * |O O J p 0 9 1 1 * || ' 3 o i* * q * 9 ) oi i 4 V O k |a |i |M ) (f w | o > 1 *1 > 1| 4 3 9 - i o f 1>*410O 9 n i q j Cl ti N 'O I 10*0 m w F M I * o a *9 q ** ) o3I4 f *0 )( 3 1 | 4 3 9 -fX * fA J * 0) 10*34*4 f ta f ir ' ) (i - I tlO O l * |< U 1*941*09 MMU 1 * c m i'm i m ro 0*0 (|* )3 4 0 O -- 3 ) 4 0 |4 * i r * 1 M I *0 f ! W |* 4 ph m * o i*o q *9 i*9 3 J*4 ( |H l ||M l V (t t a f ; 0 O 3 o j * * 4 Cl ) n iiu ]i} fix o (' ) 1*94 1*09 * * n u C C l IC I VO 1 0 0 4 * 4 4 * ) * t|J * 1 9 A ~ > \ S * ! < |H S * ta f 1 9*3 ) * ! *1 *0 1 9 9 * p9 ta f 1900 > |01-- 00 ro q i* l * l *! 7 ta rd a v i / ll tA )139 JC 0 0 1 1 *4 1 1 0 ' 1*91 JO * l 0 <{ /> I f 1941 -09JU O 9 pJn*A M l ||l ) l l IsnpoaO * *l*9 q * V 4o t*i*3 l * f u l I I U I |I | (panujauoD) u aiffVl T* |B IS M'ik \ A 128 TABLE 27 ( c o n t in u e d ) A i U it o i product c ( t fy la b o a to o p roduct C u llili u 4 H a lu C l (c o o tlo u c d ) K o ala c o o tlo t* < d r y v o ll coupoMod ( le a li i k |]fPUO") M d l i T a l l c o f ottod (to d / ) A c t iv it y perform ed lo a d b lo a tin g h ig h porfotoaoco a n te rio r c lin g A p p llc c tlo o M ix log (d ry powder) ( iri- a ii) Mood a io d i | /ok acadlot ra t* iu ll> | Iw itp lll l M p la | r r a ln i.* ( 0 . 9 t o 1 .5 ) cod te n d in g ( O . f t o 1*5 to) Honoured lite r co ncio * t r o t iv o (f/c o '> Data o f to a ta D u re tio o of a c tiv ity / t loo ( . 1.) A a a lyt ic a t o a t bod Co-- v a t ui. 0.2 to 0.2 1919 y to 2 j 0.4 t . 1.) 2.0 to 12.4 2*2 2.1 to 24.2 1.2 to 10.1 t.i t. 10.0 4.0 t . 14. 5 14.5 t . 15.4 15.4 t . 59.0 197* 1975-1977 1975-1977 1975-1977 197* 1975-1977 197* 1974 59 t . 45 10 to 11 10 t o K0 10 t . 1* 4 | . 11 9 t . 50 10 1 * 10 m 1.5 I . 1974 R 14.9 Pbeoe c o o tra a t IlM IM l) Fbeee c o o tra a t O perar o ra l a m l l l i i t i i u K2 -- t a r d ia --a t c r by 1 .4 --a l a r b ig b t a t i t i n i a pray coatad la 191) v i t b a 2 .1 per- c o at log* C o n a t e i a 1 o p a r a tlo a . it K a e id a o tla i e a ttta g . 1 . . it B e a id a o tla l e e ttia g . it K a a id a a tia l a a ttia g * It C o n o r c i a t o p a r a tlo a . It K a a id a a tia l a a ttio g . It Co----o r c i a i o p a r a tlo a . it Fhaee c o o tra a t Caaoaarcia) o p a ra tia a . F ib e r r n | t raportad ia oot la ta back g ro und ta v o la , which f o r th e aa--a roo-- ranged fro -- 0 .5 to 1 1 .1 1 fern 1 . C n --o r c i a i o p a r a tia a . F ib e r range raportad i t o ot laao back* g ro u nd la v a la , which fo r tb o a n a t o o * raagad f r a 2 .1 to 1 .5 l/ c a 1. 15 15 `  i a k i t * p iW u c t p ro d u c t TABLE 27 (c o n tin u e d ) k t i v i t f ^ rfo rv d M e e a u re d fib e r coocoot r o t too ll/cmh Dec. a( to o to D u ro tio a of ic tif it;/ e u p lio g t ioo (a la ) A n a ly tic a l tb d CoMHQt U (. 129 ( c M in H ) . ` M id 4 rp ll co^oud llt< 4 | ) to t# (0 .* u d in | Ca 1 . ) a ) Sweeping f lo o r 0 . 0 Ca 1 ) a ) 1.2 to i .j 1*74 41.4 (m u ) 1474 T o z c lla . liM a t o i c lo th a d i h ; w aC -rroca.aio tlC M ifl l K d t 7 procooeiog of d o th 0 .4 4 , 0.40 1472 t ik a it t a c la c k *a4a by M t a| r o C M l i l | techniq ue U o ro llio i, M i i u r l i i i c u ttin g w ith i c i i i o r i nod f o U l o i o f c lo t h 0 .JJ, 0.4 1471 r in p c a a f c la c k la U o iriit iiM it o i f ir " p ro o fing c lo th ia g t . (u n tre a te d M t t r l i l ) S to ol i ll- lo o t furnnco w orkoro 0. 2-5.0 1474 (TWA 0 .1 ca 1.1) f h o if h o m p lo o t- e d u c tio n furaoco 4 .4 - 1 4 .2 Cm A 4.7) 147 n Co-- i re i o l o p e r a t io n . n F ib e r ron g t reported i l oot to back* grouod lo ve ! , which f o r tho i i m roo ranged fro ).5 to 1 4 . 1 / c 1. m f k m coot roo t Du* to b eery lo ad ing 15 d u rin g w e e p in g , a a a p ltn g occurred 1) o io u to o o d o r iw*p- lo g topped, l i t e r )5 o in u te e , the M a tu re d fib e r le v e l wo 24.A f/c * 3 . n ffeeee c o o tro o t Volueo re p o rte d o r 14 o ic ro tc o p y f o r oo a re a ood p er- a n a ly o le o o o l oao p le, resp e c t iv e ly . S p e c ific * about e c tiv itie e per formed o o t re p o rte d M Vo lueo re p o rte d ore u a ic ro e c o p y f o r oo e re e end e o e ly a le p e rso n a l eanp le, re s p e c tiv e ly . 2 fhooo c o o tro o t A c tu a l a an p tin g le 1) (o ? iro | i) p la n t. i Phoae c o o tro o t A c tu a l p e o p lin g io 17 (> n tl| a l p la n t* (i m i Im I) TABLE 27 (continued) 130 c TABLE 27 (c o n tin u e d ) * Neaeurnd h iritio a of 1 lib il activity/ A cooccn- a a flia i t iW t t u prevail cat torf Aatoatno product A ctivity fr(ara*4 tratio ll/tmb Data al taata t in (ala) A u ly t teal Mtbod Commata la (a TEI Caakaca u l I K k l v i Co^reeeed aaWatna . Itorat (or hm bt |M k tl M<d punching *0.01 ta 1970 0.11 1.00 197 Iced puncklng li*4 tfrat4 M C tu ilc d punchit Nachitt paackiap * <0.01 ta 197 0. 1) <0.01 197 S.O 197 Hackiaa paachla| <0.01 to 197 0. ) Haeklaa pw w M n <0.01 ta 0. 0 197 , la a l ahaplac <0.05 to 197 0. ) Hacfcln abenring 0.1 ta 197 1.) Maclalaa abaariac 0. 0) ta 197 0. 1) 97 ta 111 Oo c o n tro l.9 l o t i * 21 Coring cooductad under actual work conditio. n Photo coatraet 0o cootrola Nooi- 71 Coring conducted udr ctual work coaditioa. 1 ta 11 HmilL*yio|. 11 Nooitorinc conducted uodor actual work conditio. HI Photo cootroot No con tro l. Moni-* It Coring conducted under ctual work condition. MB Photo cootroot No con tro l. Hool" 11 taring conducted uodor actual work condition. 10 ta M Phoo cootroot NowMktyia|. 11 Hoaitoriog cooductd under actual work condition. 1 ) ta 11 Phoo cootroot Noueekeepiag od 11 ant i lac ion.*1 Honitorint conducted coadit too. 7 to 11 Photo cootroot No con tro l. Honi- 21 Coring conducted 0 11 ta 1 condition. Phooo cootroat No con tro l. Honi- 11 torin c conducted unde* actual work cooditiooe. Photo cootroot Uoueakeapint* 21 Hooitoring conducted under actual work conditloaa. (c w i Im M) f TABLE 27 (c o n tin u e d ) 132 U k i i U f product category Aateitoa product C aiU ti ta4 p *d d a|l (toot Inuod) C afwnV iiU a tu kM t gaakota * Coofraaaad aakaataa ahaat gaakata A ctivity ftrlonM ^ NMttr4 fiber coaeta- trncioo <l/cJ> RiClliM nibbling <0.08 to o .u KaeldM * U k lii| / Installation of flange gaakat 0.08 to 0.8 <0.01 Raooval aod coocurroot iaatallatioa ( io ll.i kaadar gaakata) Claaa-vf fallowing raooval by hatd a c r a fia i 0.02 to o .s 0.05 la a o n l .a * kaa< .craplag 0. 0* to 0. I t RaaMVil atod v iro kruaMag <0.01 to 0.10 D*te of U lU 1*7* 1110 It)* It)* lt)l 1*71 1*71 h a ck pnaa operation 0.08 to o . r 19(0 h o a r aktav operation 0.17 _ |*(0 (cM tim O Dur.tioa 1 activity/ aaa^liat tiaa (aiia) A n aly tica l MtbOd CoaMoti 1* 1. 24 to 10 Jl ta *5 1) ta 17 IS to 1* 2) to 11 80 to 111 it* Rm h cflitrait fkaai cootroot Phaaa cootroot Ffcaao cootroot fkaaa cootroot flb e ro wore countod by fkaia cootroot with r u t 1 varilicatioo fib e r* worn counted by fkaaa cootroot vitti flit verification *o con tro l. Moni n toring coa4uettd odor actual work ioai. Moueekeeping. n Monitorial conducted under actual work condition*. No control* Noai' ii to rit^ cooductad cood it lo o t. b>uiktfint. to o l- 21 to rlu i conducted under actual work condition** No con tro l. Honl- 21 Coring cooductad under actual work condition*. Mo co n tro l. Mool- a totin g conducted under actual work condition*. Moueekeeping. Honi- n toring conducted under actual work condition*. Monitoring performed 22 at nejoc gaakat fab- ricetor located Is Viacooeia. M onitorial perfom*l n at okjor gatkat lak- ric o to r located in Vieconaio. TABLE 27 (c o n tln u e d ) kabeato produci <<ti|or| A iW tto i prodvet peckiage (come 1h 4) < efcaat gikt I * . * Compraaaed u N a t o a Wat |w k au A c tiv lty parformed Sbear fraaa operai(oe Im i m I proaa ' I ibr conce" Crat io U/tm h 0.21 ta 0.11 0.04 ta 0.00 Date o( reati 1910 IMO r u t t i oyarat toa - 0.10 t 0.11 1990 T m h tlll parati 0.42 ta o.to 1910 MatartaU haa*llo* 0.11 ta IMO 0.14 riataa praaa optratto 0.01 t . IMO 0. 2* ficee proa# operati ydreallc laaa praaa 0.01 ta IMO 0.15 0.02 to IMO 0.05 ( c o a tta .* ) Ouretioe of a e tiv itf/ aaaplia t ime (aia) inaly tir e i octbod 50 ta 24 100 ta 1*1 *1 ta 204 17 ta 141 *1 ta 214 52 ta 154 41 ta 210 fibara vare counted by phaaa c o a tr ilt v itb PLH ver ilic e tio fibara vara couoted by v it b FlU v e r ific a i io fibara vere covnt4 by pha cootraet vitb flit v e r ific a ti Fibara ver covnted by phaaa cootraat vitb flit v a rlfic a tio fibara vare counted by pbaea coatreet vitb flit vari!icatio fibara vara counted by phaaa coetraet vitb flit rerifIcatlon 41 ta 17* Co-- iot i Iti. N a a lte rlo i per(ormed i i at major gaaket ft>r ic a io r locatad io Viacoeaia. Moaitoriog parformed 12 at major gaaket fbriceto r locatad io Viocooaln. Monitoring parformed 22 et major gaaket labriceto r located la fi ecooeia. Monitoring parformed 21 et mejor geeket lib r ic e to r iocetod in tfiecoeeia. Monitoring performad 22 et mejor geeket f ebric e to r Located io Wieconein. Monitoring performad 12 et major gaekat febricaio r located ia Wieconein. Monitoring performed 2) at en beato" O liai gaaket oper ai oo ie tfirnnia. Monitoring pevtorved 2) t aq eebeetoaaing gaaket epera llo 1 Wieconain. TABLE 27 (continued) 134 * lag #14 roof M ttr ia U C bttia| oo4 toying m v folto 0.0) rang ioc Iu4a ir t a aoi porooool omploo tm%mm Jitriig roof rtaoval oo4 Colt ia v t a lU t ion* A TABLE 27 ( c o n tin u e d ) i<Uit<N pra^nel catctory product Activity ptrlonM i Honoured fiber cooceatr e t ion U /cm h Data of tactc Duration of activity/ <af>11 >. tic* (nin) A n alytlea l ant bod >t lef. Ae(bCecMtotelwH4P)t r B^ofiag (It Cutting ani laying fa lta 0.0 1474 m> fkaia contract f i M r concentration of 24 0.0 f/cn* report4 for ) area tod 2 pcrcooal tawplaa taken Curiae fe lt ia c ta lle t ion. Cuttiat, acrafioi a w if 0.0 1974 N> fkaaa coot root fib e r concentration of 14 iac old roof M ttrla l* Outt(a| aai liflal m w 0.0 f/cn^ reporteC fo r 4 area and k fa lta peraoaai couplet taken during roof removal and fa it io o ta lla tio n . (Vittla| and la y in g ( i t <0.1 1975 190 fkaaa contract Area aatd peraoaai 14 eaaplea taken durii^ fe lt inctaltation. 135 O i t t i i f aai toy Iof ( i l i a 0.1 tn 1974 0.1 110 Tkaa contract fib e r coocaotration 24 ranee iocludac area and parconel wanplee taken during fe lt I la w in i, a e ra fia g ) awaiy* i l 14 roaf M ta ria li 0.1 to 0.3 1974 75*110 ia c ta lle t ioa. ffccco contract fib er concaatrctioa 14 range iocluCaa area G utting cad laying m w and parconal aanplac fa lta taken during roof raatovcl cad fa it ia c ta lle t ion. la v io i, ccraping, awtf- 0.0 to 1974 HD Phacc contract fib e r concentration 24 ln| o!4 roof MtariaU 0.1 range includes area C U tti^ and lajritt| m v and parconal aaaplec falta takao during roof renova 1 anu tele i a c t a lle t ion. Aia cb ofp lai, pry In Aa4 0.1 to 1974 40-91 ftiaee contract fib e r cooceatration 24 ocrapiog, iwaaflni ol4 0.4 range iocludac ai.*j roof and parconal couplet taken during roof renova1. (continued) TABLE 27 ( c o n t in u e d ) 136 i a U i t M frorfact Cilagarf ijWiti MPr UottlaaO , I Aato.t*. *(*4wct Im I I fait ctl.itf r*rlora*4 Qattl^ and tablai (U Ckitliai i(4 Ufi (U Cuttiat a4 tafia lait KUlto.N Icon _r Saw faconda rp processing Niaiurad 1 ibar COoCtR- tracio iUcmh Oata o( tasta Durst ion ol act lait?/ sapliai lias (aia) Aaalftieal nsthod Cossninta gai. 0.1 ta m 0. 0.1 ta 0.9 t 0.1 ta 0.) 1971 (.4 19(0 1.4 19(0 i.l 1990 0.1 m (1-107 n m 10 10 10 A Phase contract Pibar concentrtioa 24 rat*a includas n s and parsone! s u p l o tafcaa durii^ fait instaklat ion. Phase contract Pibar concentrtioe 24 rangs includa* aras and personal scapita Caban during fait instailat ion. Phaaa cootraat Pibar concentration 24 rangs ineludaa aras and personal aanptca takan during fait installt Ion* (iM/ion (/no dX/lDO cauasd Taating psrfomad io > glosa boa* Tasciog perforwed lo 5 gloss boa. Tastine psrforoad in 5 giova boa. Aasanblp Involving 2V placanaot of punchsd iltboard rings on stasi nandrala to K l w t r U a l Insulating (tarifa aaaa flf paper ia4 koaHaJ package operator * Papar aaeMaa n v t d operator 0*009 co thick papar 0.014 19(0 <0.004 19(0 4) fluii caatraat asults (roa sni - 28 toring alcctrical insulsting papar product asoulac" turad bp (pjin'T Corporation, 17( ta auIta (ron noni* 71 toring olactricat intuisti^ pepar producta nanufac- turad bp Quin-T Corporation* (c**tl*u*4) TABLE 27 (c o n tin u e d ) . A alaatoa product catgory t it t M o i yaya (co a tla ..*) 1 i t i I A alaatoa product A ctivity p ttla iw i Measured iik tr coocea** fra tio < (/ > > Date ol te e te D uration of a ctiv ity / a a ^ lia tia a ( .i.) A aalytleal at hod CoHMt 0 ftef m e t r ic a l ia a u l.tia p ap ar aarf b o a rd s* fap ar machine re v io d op erator, 0.04 ca Clilch paper o .o o N llU aaH cu tter op aratar 0 .0 4 ca th ick papar < 0 .0 0 ) 1)00 1)00 M lU lag a fa ra to r. 0 .0 3 ca (k ick papar < 0 .0 0 1 1)00 t lit t la g operator, 0 .0 J ca th ick papar < 0 .0 0 1 1)00 lU lhlaadar, t a i l aao o p era to r U |k lalati a lltta r o p era to r C oll c o tte r operator 1 1 .) 0 .1 ) 1)10 1)10 o. om KD in 0 00 41 no la a u lta I roa m u * 34 to ru t ele ctrice ! is a u la t is i papar p ro io c ta manufac turad b / Q u is'T C orporation. ( a l l a tram moak- 34 to rio e le r tr ic a l le a u la tin g papar produces m anufac tu ra d bp Q u s*T C orporatloo. R esu lta fron a o n l- 34 to rio s e la c tric a l in eu latlo g papar producto M iu la c-* tu rad by Quio~T C orporatloo. Phase c o e tra e t R e su lta fro o m oni* it to rio s e la c tric a l In a u la tlo s papar produca m enufac- . tu ra d bp Q u io-T C orporatloo. Phase c o o tre e t K eference c ite s 34 ralease as e a c c s s lre . Phase eo n trao t R e su lta frcm m oni- 34 toring a la c tr ic a l ittsu latin g papar producto manufac- 't u r a d by Qun-T Corporat ion. Phase co a tro e t R esu lta (ron noni - 34 torios a lte tr ic il la i u U t i n i paper ^toducti u au fa c- ti>rd bp Qoio" I Corpotatloo. -- --- - ------ j (coi-t-i--M-a-l-)- 1 --- 1 1 -- TABLE 27 (c o n tin u e d ) 4bastar product category Aaboatoa product A ctivity performed /bar coscrs* trat ioo U / c . 5) Data ol tests Ouratioa of a ctiv itp / a a a p litf t io (oin) Aaalyc ical s i hod Coooot a * iihitta Mr (costIm 4) i B lctrical loaulatlag Coll cuttor OM fitor papor aod board*-* Acaa M N f 'cottar 0.013 m <0.008 187 le a l c a ll cuitar <0.013 19? Acaa c o if* viodlag <0.008 19? Viodiag abaratar, 0.008 ca th ick papar S littia g operator, 0.008 ca thick papar <0.008 1980 0.031 1980 X (coatlM d) 98 Phase coatraat I n u lt a (roa n oo i- ]| Coring a la c t r ic a l i a i u l i t i a i paper product M sttU c* turad hp Qaig-T Corporal loo. 91 (tufa coatraat Kaaulta (roa so n t- 71 tori| alactrica l la tu la tio g papar product a io u tic * turad bp Quio-T Corporal loo. 33 (klH coatraat laaulta (roa s o o l' 28 toriog a la ctrica l la tu latio g papar product* m quU c* turad bp Quia-T Corporalioo. 87 PHaaa coatraat ta au lta ( roa a o o i- 2| toriog a la c tric a l io su latio g papar product# maoutac~ turad bp Quia-T Corporalioo. 90 ftiaaa coatraot Raaulta (roo a o s i- 28 toriog a la ctrica l in a u la tio f paper product# ajgti(> c- turad bp Quio~T Corporalioo. 90 Phaea coatraat fcaaulte (roo oooi~ 28 Coring a la c t r ic a l ia au latin f papar product maoufac* turad bp Qulo-T Corporalloo* TABLE 27 (c o n tin u e d ) Aakcitoi product category Aabeatoa papor * (cootloued) labiata product A c tiv ity performed :r I to c tr lc a l i it lag ad board* E lectrical Ioaulatiog papar-pimeh pro oporotor (TV BOtD) Hoc trico t Ioaulatiog paper-- ahaar operator (TV BOED). E lectrica l Ioaulatiog popor-- oaaeafely dept, operator (TV BOED) SEGO, bear bocIm OD, triad lag area operator Ace beaey fcoodvladlog Meaeured fib e r coocaat r a t too (f/co*) 0.09/ 0.044 0.00 0.0)) 0.03E <0.004 Dato of toatc *D 19? 197 1979 Duritlo ( activity/ eapliag tiac (oia) A o elyticel Method I9E rtai 13) Ru m 145 Rute cootract 110 Vtiaae coatvaet 100 Rial coatraat 108 Ru m coetr#t Eeaulta fro e e o li* tarin g e le c tr ic a l ta iiiU tia i paper product maoufoctu red by Quio-T Corporal io a . I n u l t i Iron m ooI - Coring e l e c t r i c a l ioau latiog paper product a uaaufac to re d bp Quio-T Corporal loo. le a u lt fro Moni toring e le c tr ic a l io a u la tio g paper product manufac tu red by Qui n-T Co ipo r a t io n . E a a u ll* fro Moni toring e le c tr ic a l io au latio g paper product ao u factn red by Qula-T C orporalloo. l a a u l t a f r a mooI - torlng e le c tr ic a l ioeu latin g papar product Manufac tu red by Q uia-T Corporal ion. E a a u lta ( tom Moni toring e le c tr ic a l io a u la tio g papar product Manufac tu red by Quio-T C orporalioa. lai. 21 21. 28 21 28 28 (cootiouod) 139 / StiiM ) TABLE 27 (continued) 9o 4ata. * liM *V i(|ktd -A v ri|9 (h k o vr) ot roporto*. l 3 O M l ? (I* u c i 1<>0 r . : 9 --* r& '-- e> "2 !1. 'O3'5> H ! 9 I>*. 1 9 M .t 1P'S.2 SI b a .b 1i aJ * S <0 . ?mo efl. b u s s 9 9 *- e J : ! S ' J MU I 3 9 .u-C Co *X----oie-90-- *V9---- 9k*0M 30W --V 9 VS bO 9 > I fw 9 b W 5 3--9 J <a9 U bs o 9---- 0 fr 0 V -- O Xft * b O --aae--e ---*SMi--O'^ooriK --.*fobl--o --b9` bsV e 9e --? 2fl T0S : u n r :5 -- * * 9 -- -- U 0bXK 9b X 9 b w9 9 b Ok* b 3 b 0 ^9 99 .' . m . t u - Cc 312 _-- b0--b 9 w i 5. I * b 6 ^ *, Ju : 3s2 Si j r s s i r ti ah TABLE 28. NUMERICAL SUMMARY OF MONITORING STUDIES PER70RMED ON ASBESTOS-CONTAINING PRODUCTS Asbestos product category Asbestos product Number of studies^ performed on product (as presented in this report) Asbestos-cement sheet Flat sheet Corrugated sheet Roofing shingles Siding shingles Flooring products Vinyl-asbestos tiles Asphalt-asbestos tiles Sheet vinyl floor covering Coatings and sealants Asphalt or tar-based products Latex or gypsum-based products Textiles Fire and Heat Resistant Firefighting helmets Outer garments Gloves Thermal Insulation Electrical Insulation Gaskets and Packings Friction Materials Materials Gaskets and packings ' Compressed sheet gaskets Asbestos y a m packings Asbestos paper Roofing felt Flooring felt Millboard and rollboard Beater-add gaskets Electrical insulating paper 3 1 0 0 6 . 0 2 1 2 1 1 1 2 ' 0 0 0 4 2 2 0s 1 0 1 Some studies investigated fiber release from more than one product. ^Sorae studies may incorporate several test runs. cComparison monitoring covered under sheet vinyl floor covering. 141 leered during use, particularly in the case of textile products and material used as gaskets and packings. Disintegration of a product's physical cohesiveness increases the likelihood of fiber release. This factor becomes especially important when these types of materials are removed from service after the expenditure of their normal life span. ' ' Mechanical disruption which physically alters asbestos-containing products can occur during secondary processing, field fabrication, installation, in-service use, and removal. Secondary processing involves the operation of power equipment such as stationary table saws, surface grinders, drill presses, die-cutting and punch press machines, and hand held sanders and routers. These operations have the potential to release a substantial number of asbestos fibers. However, to comply with occupational asbestos exposure standards, these processing machines and cools are normally equipped with engineering controls to minimize workroom contamination. Further worker protection is accomplished by the operator' use of a respirator and personal protective clothing. Manually operated tools, such as scissors, scoring knives, and hand saws, may also be used during secondary processing of asbe3tc3 products. However, the alow cutting speed associated with the use of these types of tools minimizes dust generation, and just aa important, imparts a low propellant force which minimizes particle dispersal. Scissors and scoring knives make clean edge cuts generating only small quantities of loose particles. Cutting using hand saws produces coarse-size particles that setcle rapidly to the ground. Mechanical disruption of asbestos products can also occur prior to and during installation,when total field fabrication or partial alteration of a prefabricated product is required. Tools used range from hand held power saws and drills to knives for scoring and scissors. Dust control practices, which may or may not be employed to minimize fiber release from these activities, include using power tools equipped with vacuum exhaust collection systems, moving the fabricating operation from indoors to outdoors where greater air dispersion and dilution lower fiber concentrations, thoroughly wetting the point of physical contact where the tool and material meet, and controlling the exertion applied when operating hand tools to minimize pulverization of the product matrix and subsequent fine dust entrainment. In many cases asbestos fiber release is generally the lowest if not nonexistent during product installation. Asbestos-containing products are usually purchased, clean and prefabricated, ready for use. Installation of the material usually requirea only simple mechanical dexterity and common sense. Once installed, many Asbestos products will not release fibers. Due to their rigid physical structure, most asbestos products are used in stationary or static applications. In use, the material is subjected to little or no direct physical force or abrasion. Only fire and heat resistant protective clothing, dynamic packings, and millboard used in hot material transfer rollers are involved in active or mechanical applications. 142 Removal of worn out asbeaCos product, ac the end of their service life la normally performed by hand. Control practices described above under field fabrication and installation, may be similarly instituted duri-g product removal. Material wetting followed by controlled energy input can effectively minimize fiber release. Many examples of this are presented in the report but one in particular serves as a good illustration. Dry scraping of residual flooring felt during aubfloor preparation resulted in airborne fiber concentrations ranging from 1.0 to 2.17 f/cnr*, whereas wet scraping of the same material resulted in a measured airborne concentration of 0.48 f/cm^. Whenever possible, asbestos-containing products should be fabricated, when required, using hand operated cools instead of power tools. Power tools such as circular and sabre saws, drills, sanders, and routers pulverize the product matrix, creating a fine dust. Duriag mechanical disruption the physical cohesiveness of Che product matrix is disintegrated to the point where free-form asbestos fibers may be released. Additionally, the size of the fibers released may be altered (decreased) from their original dimensions. The fine dust generated is easily entrained by the high speed cutting implement of power tools and can remain suspended in the ambient air for long periods of time. Differences in airborne fiber concentrations are also expected between various power tools. For example, material drilling will pulverize the product matrix, generating a fine dust, but the particle propellant force is somewhat restrained compared to that of a circular saw. Dust generated during drilling tends to accumulate near the drill bit and is not dispersed to any great extent. The cutting action of a circular saw, however, is much more vigorous, providing enough energy input to propel the fine dust generated quite a distance from the point of contact. Because of these factors, asbestos product manufacturers and equipment designers recommend the use of power tools equipped with vacuum exhaust dust collection systems. With respect to hand operated tools, engineering controls are not normally used because these types of tools do not generate fine dust nor do they propel the particles into the ambient air with the same force as power tools. Dust particles generated during Che use of hand operated cools are coarser chan those generated by power tools. These coarse, comparatively large particles tend to settle rapidly near the operation, minimizing ambient dispersion and residence time. In summary, easily implemented and uncomplicated control practices have been developed by asbestos product manufacturers, industrial trade associations, and product distributors. These practices have been well publicized and documented in training manuals and product brochures. However, due to a myriad of reasons, they are not always followed. Many times, simply for convenience, dust control equipment, work practices, and protective _ . equipmnt will be ignored during asbestos product handling and processing or if established control measures are used, they frequently will be improperly implemented. 143 Airborne asbestos fiber concentrt ions resulting from secondary processing and end use activities routinely or most frequently performed on certain asbestos-containing products have been presented in this report. These data will be used inconjunction with population exposure data (both occupational and nonoccupational) and product usage information to prioritize candidate products for testing under future EPA monitoring programs. Following prioritization based these criteria, products selected for initial testing can be further classified according to the following: Product testing to create a data base where one does not exist, or Product testing to expand an existing data base. Testing would be performed to validate results of previous studies or to monitor ocher product handling activities that have not been examined. Asbestos-containing products not profiled in this report, which include asbestos-cement pipe, friction materials, reinforced plastics, paper pipeline wrap, commercial paper, and specialty paper are also potential sources of airborne asbestos fibers. These products and those that were investigated but are not recommended for initial testing (see below) may be evaluated under subsequent monitoring programs. Based on the information compiled and the prioritization scheme described above, Table 29 identifies the asbestos-containing products profiled in this report that require first time testing or further investigation. These products are listed below in descending order of testing preference. Product handLing activity, tools, and duration of activity to be performed, used, and monitored during testing are identified, respectively. Product Activity Tools Duration Millboard (paper product) Sawing, drilling, hammering, and/or scoring Uncontrolled power tools and hand tools 1 to 10 minutes per operation Flat A/C sheet Sawing, drilling Uncontrolled power tools 1 to 15 minutes per operation Gaskets (textileuntreated rope) Cutting, hand manipulation, removal Scissors, razor, or utility knife; flat-bladed knife or wire brush for removal <1 to 10 minutes for cutting and handling, 15 to 30 minutes for removal Packings (unlubricated braided yarn) Cutting, hand manipulation, removal Scissors, razor, or utility knife; flat-bladed knife or wire brush for removal <1 to 10 minutes for cutting and handling, 10 to 30 minutes for removal 144 TABLE 29. ASBESTOS-CONTAINING PRODUCTS AND ACTIVITIES OF CONCERN RECOMMENDED FOR INITIAL FIBER MONITORING STUDY fro^act ct|*r7 Product iiUitoi* cmmK ahoat products r u t akatt A ctivity f* c o w a n Toolfa) Localioo of activity D u rtioo tod vaa iovolvlag (laid fabrlcatioo Uocont rol lad poaar hand toole (circular eaua, drille aaodara) lodoort or outdoora Totality aavaral nloutee ovar couraa of day Capactad fibar coocaotratiooa frow a c tiv ity * i'h Tastilaa f tr a a4 boat Wearing of RA raniment gantante clothing (uatm tat, coated ioaar eurfecee) and vor> clothing Thermal Iiaa* nutation (tap#i clotb) Cutting during in a ta lla tio o aod rnovai of material froar proceee equip* cat or traoafor pir*. Koivea u t i lUp r.a.r bladaa latoori or oucdeere Op to 4 boora at o tloo tor w aring clothing todoora prlu ritp . but alao outdoora Cutting to tallin g a fou minuta#. Raooval laatin g aavaral oioutaa to houra depend* tag on aatant of materia! appli* cation Moderate to high Nodarata to btt b Caaiutje ( i n t t a i rap.) Cutting durlag in atallat'io n aod removal of uornout n o taria l and etoaaiog of Joint aorfaeaa Sciaaora, Indoora knivaa for prim arily cu ttin g , f la t * but alao blodad putty outdoora knife, ulra bruabp poaaibly haad aaadlag during n a o v a l. Cutting to tallin g o fou oioutaa. 15 to 30 minuta# (aat.) for ra n o v a ! Modarata to hi( k Aabaato coataot of product (I) b lit ii| liW t M aitorioi 15 to 40 75 to 100 2 .) to 195.1 i/1 <rot M lflil) lotting p a r fornad uodar laboratory coaditioaa to ooavaat t l a t a l |U v * boa cbaaibar 0.3 to 24.2 l/cm* (rex enalyaie) To gaaaratt b t i rtpra ta tiv t of actual (litl coofitioil. Validation of fibar cooctr tro t too# ata* eurvd. 73 to 100 7) t . 100 0.0 to 0.05 f/ca' (fOI analyala aaa* ad). Monitor* log occurred during cutting aod io t t a lla at ioo of untraatad lagging cloth. Validata gaaarata aod data, Mo data raportad Caoarata data (condoned) TABLE 29 (continued) cT*atlta gaakata Mlf, tutlll packlaga will to pnistt4 n4tr tto gaakata u U gacklaga product eatagory 146 -mdd K kec (paper product) Activity, Cutting, hand manipulation, removal 6. Fire and heat Wearing, hand resistant garment manipulation (textile clothing, hoods) TOOlS Scissors, razor, or utility knife; flat-bladed knife or wire brush for removal Mot applicable Duration <1 to 10 minutes for cutting and handling 15 to 20 minutes for removal 5 to 15 minutes total 7. Thermal insulation (textile) Cutting, tearing, ripping, hand manipulation Scissors or utility knife 5 to 15 minutes total Product handling activities to be monitored are those that are routinely performed. For example, during field fabrication of A/C sheet products, recommended work practices include the use of engineering controls to minimize fiber release during sawing with power tools. Monitoring data show that under these conditions resulting airborne fiber concentrations are less than 0.2 /cra-*. However, it has been reported (see Section 2) that field fabricating of A/C sheet products is also performed using power tools that are not equipped with dust control devices. Although not well documented, this latter practice is suspected to be fairly common. Consequently, because this situation does exist and fiber release from the cited activity is expected Co be high, product testing of flat A/C sheet usiog uncontrolled power tools is recommended. In summary, the products listed in Table 29 have been selected because fiber monitoring data are insufficient or nonexistent and fiber release from product handling activities associated with the products is expected to be high. Asbestos products not listed in Table 29 were excluded from recom mendation for initial' testing based on a combination of the following factors investigated under this study: Airborne fiber release from the product's end use activities has been well documented. The products have a low asbestos content. Product handling activities result in minor disturbance to product matrix and last for short periods of time. The products have a strong structural cohesiveness whereby the asbestos fibers are tightly bound within the material matrix. - Well designed and implemented engineering controls and work practices are almost always instituted when product handling activities are performed. 147 Asbestos-Cement Sheet Produce (Section 2) Flat Sheet: Recommended for testing (see Table 29). Corrugated Sheet: Not recommended for testing. The product composition is the same as flat sheet, testing results from flat sheet vill be directly applicable. Testing of flat sheet is recommended over corrugated sheet because of the latter's limited use. r Roofing and Siding Not recommended for testing. Shingles: Limited field fabrication is performed, most shingles are prefabricated by the primary manufacturer for direct installation. Fabricating tool (guillotine cutter) used in field causes only minor dusting. ) Flooring Products (Section 3) Vinyl-Asbestos Not recommended for testing. Floor Tile: Fiber release from end use activities associated with floor tiles has been well documented. The product's polymer matrix binds \ asbestos fibers, minimizing release. Low-energy mechanical disturbance is applied during installation. Comparatively high fiber concentrations may result during removal and subfloor preparation if recommended work practices are not followed, which is not 1. normally the case. Aaphalt-Aabestos Not recommended for testing. Floor Tile: Same as above-- except not well examined with respect to monitoring studies. Fiber release from asphalt-asbestos floor tiles is expected to * be similar to vinyl-asbestos tiles. Sheet Vinyl Floor Covering : (backed with asbestos felt) Not recommended for testing. Fiber release from end use activities associated with this product has been well documented. Lowenergy mechanical disturbance is applied during installation. High fiber "concentrations may result during removal and subfloor preparation if recommended work practices are not followed, which is not normally the case. 148 Textiles (Section 5) Not recommended for testing. The asbestos content of these products is comparatively low (5 to 30 percent). With respect to petroleum-based products, asbestos fibers are tightly bound in the tacky product matrix. Airborne monitoring studies reveal comparatively low concentrations of fibers during the application and removal of petroleum-based coatings and sealants. Use of water soluble products is limited strictly to industrial applications. Fiber release from these products has been well documented precluding the need for additional testing. Fire and Heat Resistant Materials: Apparel recommended for testing (see Table 29). Other materials not recommended for testing. Heat shields, splash curtains, and blankets are normally surface-treated to minimize fiber release. Also, they are mostly installed in static applications and therefore are not recommended for testing. Thermal Insulat ion: Recommended for testing (see Table 29). Electrical Insulation: Not recommended for testing. These textile materials are usually concealed or incorporated into internal parts of appliances or electrical wire. Only minor mechanical disturbance is applied to textile material during secondary processing and end use. Gaskets and Packings: Gaskets - Certain gaskets (untreated rope) recommended for testing (see Table 29). Fiber release from surface-treated textile gasket material is expected to be low and only minor mechanical disturbance occurs during performance of end use activities. Therefore testing of treated gasket material is not . recommended. Packings - See discussion below under Gaskets and Packings. 149 b ^ommended for testing. yf,er is often laminated with structural fiber and adhesive by a secondary processor before it is incorporated into an electrical appliance. Only minor mechanical disturbance will occur to the paper during end use. ,jre product testing studies should include an analytical technique provides results that are fiber specific and consistent. The technique must be capable of distinguishing asbestos fibers from nonasbestos fibers and identifying fibers over a wide size range. Of the analytical methodologies most commonly used to determine airborne asbestos fiber concentrations, phase contrast microscopy (PCM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), only the electron microscopy techniques are capable of meeting the analytical criteria requisite for a meaningful product testing program. Phase contrast microscopy is not capable of differentiating asbestos fibers from nonasbestos fibers nor is it capable of identifying fibers less than 5 urn in length with an acceptable degree of reliability.** Scanning electron microscopy and transmission electron microscopy offer separate advantages. Upper end magnification and image resolution for scanning and transmission electron microscopes are lOO.OOOX and 250,000X, and 20 nm and 0.4 nm, respectively. Scanning electron microscopes provide better observation of surface topography and enable viewing of a relatively large number of fields in a short period of time. Transmission electron microscopes in offer superior image resolution and morphological characterization. * Transmission electron microscopes, with selected area electron diffraction (SAEU), are capable of distinguishing asbestos fibers from nonasbestos fibers, and chrysotile asbestos fibers from other (amphibole*) asbestos fibers based on differences in crystalline structure. However, because amphibole asbestos fibers exhibit similar diffaction patterns, TEM/SAED analysis is not capable of differentiating amphibole asbestos minerals from each other.32,33 Fiber identification using a scanning electron microscope is limited because electron diffraction studies are not possible.^ However, a scanning electron microscope equipped with an energy dispersive x-ray (EDXR) spectrometer can be used for qualitative analysis. EDXR is an electron beam microchemical analytical technique that provides semiquantitative elemental analysis of the fiber(s) under observation.33-35 Because the fibrous minerals exhibit characteristic x-ray spectrums, qualitative identifications can be made. Transmission electron microscopes can also be equipped with an EDXR s p e c t r o m e t e r . ^ Amphibole asbestos minerals are araosite, crocidolite, and the fibrous forms of actinolite, anthophyllite, and tremolite. 151 It ia important to note that some fibrous minerals produce similar elemental x-ray spectrums, thus prohibiting individual identification. Unless the mineralogy of the fiber source is well known, the results of SEM/EDXR analysis should be interpreted with d i s c r e t i o n . ^ In cases where the fiber source is not well known, the use of TEM with SAED and an EDXR spectrometer can provide accurate qualitative results. The SAED capability of TEM enables differentiation of fibers exhibiting similar x-ray spectrums based on characteristic crystalline diffraction patterns. A transmission electron microscope with SAED and EDXR capabilities is one of the most powerful analytical tools available for airborne particulate and fiber s t u d i e s . ^ f ) 5 I IS 2 CONCLUSION AND RECOMMENDATIONS REFERENCES 1. Cog ley, D. et al. The Experimental Determination of Asbestos Fiber Size Distribution during Simulated Product Use. Prepared by GCA/Technology Division for the U.S. Environmental Protection Agency, Office of Pesticides and Toxic Substances, Washington, D.C. October 1981. 2. Asbestos Information Association/North America. Recommended Work Practice Procedures for Asbestos-Cement Sheet. Submittal to U.S. environmental Protection Agency, Office of Toxic Substances, in response to Advance Notice of Proposed Rulemaking: Commercial and Industrial Use of Asbestos Fibers. Docket Number OTS 61005. 3. 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