Document 3NRJy4OqY80ywky2VN2eyvkVy

LIST OF TABLES Number 2.1 .2.2 2.3 2.4 2.5 2.6 3.1 3.2 3.3 3.4 3.5 3.6 3.7 4.1 4.2 4.3a 4.3b 4.4 Page Approximate Chemical Formula of the Asbestoses 5 Chemical Composition of. Common Fibrous Silicate Minerals 6 Chemical Composition of Asbestoses from Different Geographic Locations 8 Physical, Chemical, and Mineralogical Properties ofVarieties of Asbestos 9 Chrysotile Grades by the Quebec Standard Test 13 Modifications in Grading American Mined Asbestos ' 15 Captive Fiber Sources for the Major American Asbestos Product Manufacturing Firms 22 Twenty of the Largest U.S. Asbestos Product Manufacturers 23 Asbestos--Based Activity of Some Major Asbestos-Manufacturing Companies 24 Industry Specialization and Primary Product Class Specialization for Asbestos Product Producing Establishments: 1972 25 Asbestos Products Manufacture: Distribution of Plant Sizes 27 Asbestos Products Manufacturing: Total Employment as a Function of Size of Facilities 27 Asbestos Products Manufacturing: Total Value of Shipments as a Function of Size of Facilities 28 Mine Production of Asbestos 31 U.S. Export of Asbestos (Unmanufactured) for 1965 - 1975 32 U.S. Export -- By Country -- of Asbestos (Unmanufactured) In 1975 33 U.S. Export -- By Country -- of Asbestos (Unmanufactured) from January, 1976, to June, 1976 34 U.S. Exports -- By Country -- of Asbestos Manufactured Products in 1975 35 v FMS1 04826 ASBESTOS INFORMATION ASSOCIATION NORTH AMERICA 1835 K Street. N.W., Washington. D.C. 20006 (202) 223-4885 27 April 1977 Memorandum For: Subject: R. Iwarsson, Abex Corporation W. Jones,, Safeguard Automotive Corp. J. Marsh, Raybestos-Manhattan, Inc. * J. Riopelle, Bendix Corporation W. Sleeth, Royal Industries B. Zacharias, Molded Materials Company t EPA Contracted Study with Syracuse University Research Corp -- Friction Materials In May of 1975 the Environmental Protection Agency contracted with Syracuse University Research Corp. for an Industrial Chemical Market Input/Output Profile in connection with studies of its Office of Toxic Substances. The contract (initially listed in the amount of $99,700) has been dis continued because of lack of funds, we have learned. However, on the subject of asbestos in the study, the general sections, and a section on friction materials were completed and submitted to EPA in draft form. This material is forwarded as a matter of interest. Please be advised that the paper is in draft form and has not been formally released by EPA. Therefore, it should not be quoted. The work by Syracuse University Research Corp. appears to be of high quality. Your comments will be appreciated. Hr. H. Mereness , Executive Director cc: Standards & Technical Committee (Rhodes, Weaver,Weber, Fenner) Mr. Drislane, FMSI RHM: v Enclosures FMSI 04827 List of Tables (Cont'd) Number 4.5 4.6a 4.6b 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 5.1 6.1 6.2 6.3 6.4a 6.4b 6.5 6.6 Page U.S. Imports of Asbestos (Unmanufactured) for 1965 - 1975 40 U.S. Imports -- By Country -- of Unmanufactured Asbestos in 1975 U.S. Imports --By Country -- of Unmanufactured Asbestos, January to June, 1976 42 43 U.S. Imports for Consumption of Asbestos U.S. Imports -- By Country -- of Unmanufactured Asbestos Products in 1975 Asbestos Supply-Demand Relationships, 1965--75 (Thousand short tons) * Asbestos Distribution by End Use, Grade, and Type, 1974 (Short tons) Buyers of Asbestos and Asbestos Ore 44 45 46 46 47 Time-Price Relationship for Asbestos 49 Recent Prices of Various Asbestoses Projections and Forecasts for U.S. Asbestos Demand by End Use, 1973 and 2000 (Thousand short tons) American Asbestos Mines and Mills Value of Shipments of Asbestos Friction Materials U.S. Manufacturers of Asbestos-Bearing Friction Materials 50 51 55 60 62 Binders and Property Modifiers in Automotive Brake Linings Average Brake Lining Composition 76 78 Brake Lining Compositions from Patent Literature 79 Summary of Published Data - Asbestos Emissions from Brake Lining Use 82 Estimated Asbestos Emissions by Jacko and DuCharme (1973) from Vehicles 90 vi FMSI 04828 List of Tables (Cont'd) Number 6.7 6.8 6.9 *Page Estimated Asbestos Emissions from Vehicles Using Rohl et al. (1976) Figures for Asbestos Content of Wear Debris 92 Asbestos Concentration During Automobile and Truck Brake Service 94 Asbestos-Free Composition of a Disc Brake Pad 97 vii FMSI 04829 LIST OF FIGURES Number Page 2.1 Schematic Diagram of the Structure of a Chrysotile Fibre Formed of Several Scrolls of Individual Crystallites 3 2.2 Schematic Diagram of the Crystal Structure of an Amphibole 4 Fiber, Indicating the Unit Cell Based on X^Sig022 (OH)2 -- 3.1 Asbestos Industry Structures - 3.2 Asbestos Products Industry 4.1 Asbestos - Salient Statistics 19 20 30 4.2 U.S. Asbestos Demand, and Projected Trends to 2000 r 5.1 Possible Areas of Asbestos Deposits 48 53 t 5.2 Asbestos Mines in the United States 54 L 5.3 Quebec Production Trends, From Analysis of 1951 - 1970 Data 57 r 6.1 Geographical Dispersion of U.S. Friction Materials Plants 66 i L_ 6.2 Dry-Mixed Brake Lining Manufacturing Operations 69 i - 6.3 Wet-Mixed Molded Brake Lining Manufacturing Operations L 6.4 Molded Clutch Facings Manufacturing Operations ! 6.5 Woven Clutch Facings Manufacturing Operations 71 72 74 viii FMSI 04830 DRAFT TR 77-515 CHEMICAL MARKET INPUT/OUTPUT ANALYSIS OF ASBESTOS TO ASSESS SOURCES OF ENVIRONMENTAL CONTAMINATION William M. Meylan Philip H. Howard Sheldon S. Lande Center for Chemical Hazard Assessment Syracuse Research Corporation Merrill Lane Syracuse, New York 13210 Contract No. 68-01-3224 - Task III SRC No. L1273-08 March 1977 Project Officer - Robert J. Carton Prepared for: Office of Toxic Substances U.S. Environmental Protection Agency Washington, D.C. 20460 FMSI 04831 NOTICE This document is a preliminary draft. It has not been formally released by EPA and should not at this stage be construed to represent Agency policy. It is being circulated for comment on its technical accuracy and policy impli cations. ii FMSI 04832 TABLE OF CONTENTS Page 1.0 INTRODUCTION 2.0 DESCRIPTION OF ASBESTOS 2.1 Composition and Propertiesof Asbestos 2.2 Asbestos Grading 2.3 Major Uses of the Asbestoses 2.3.1 2.3.2 2.3.3 2.3.4 2.3.5 Chrysotile Crocidolite Amosite ' Tremolite andActinolite Anthophyllite , 3.0 DESCRIPTION OF THE ASBESTOS INDUSTRY 3.1 Industry Structure 3.2 Types of Plants 3.3 Numerical and Percentage Distribution of Plants, Employees, and Production 4.0 MARKET INPUT/OUTPUT DATA 4.1 Mine Production 4.2 Exports 4.3 Imports 4.4 Supply-Demand-Use 4.5 Asbestos Fiber Prices 4.6 Future Outlook 5.0 MINING AND MILLING 5.1 U.S. Mines and Mills 5.1.1 Ore Characteristics 6.0 FRICTION MATERIALS 6.1 Statistics 6.1.1 6.1.2 6.1.3 6.1.4 Use Quantity and Shipment Values Industrial Firms Plants Future Projections forAsbestos (Clifton, 1975) 1 2 2 7.1 7.2 12 7.7 17 18 18 19 19 2^ 26 29 2^ 32 41 41 52 52 56 59 59 59 81 65 67 iii FMSI 04833 Table of Contents (Cont'd) 6.2 Manufacturing Process Technology PaRe 68 6.2.1 Molded Products 68 6.2.1.1 Dry-Mix Process 6.2.1.2 Wet-Mix Process 68 68 6.2.2 Woven Products 70 6.3 Composition of Friction Materials 73 6.3.1 Binders 6.3.2 Property Modifiers 75 75 6.3.2.1 Non-Abrasive Modifiers 6.3.2.2 Abrasive Modifiers 75 77 6.3.3 Composition 6.3.4 Summary 78 78 6.4 Asbestos Emissions from Brake Lining Use 80 6.4.1 Published Literature 81 6.4.1.1 6.4.1.2 6.4.1.3 6.4.1.4 Discrepancies in Asbestos Content of Emissions or Debris Collection Methodologies and Particle Size Distribution Analysis Techniques Other Considerations 81 85 86 88 6.4.2 Emission Quantities 6.4.3 Human Exposure to AsbestosEmissions During Brake Lining Maintenance and Repair 6.5 Alternatives to Asbestos as a Friction Material 89 91 94 6.5.1 6.5.2 6.5.3 6.5.4 The Role of Asbestos in Friction Linings Alternatives in Brake Linings Alternatives in Disc Brake Pads Alternatives in Clutches 94 95 96 97 6.6 Summary and Conclusions for Asbestos Friction Applications 98 REFERENCES 101 iv FMSI 04834 List of Tables (Cont'd) Number 6.7 6.8 6.9 ^a8e Estimated Asbestos Emissions from Vehicles Using Rohl et al. (1976) Figures for Asbestos Content of Wear Debris 92 Asbestos Concentration During Automobile and Truck Brake Service 94 Asbestos-Free Composition of a Disc Brake Pad 97 vii FMSl 04835 LIST OF FIGURES Number 2.1 2.2 3.1 3.2 4.1 4.2 5.1 5.2 5.3 6.1 6.2 6.3 6.4 6.5 Page Schematic Diagram of the Structure of a Chrysotile Fibre Formed of Several Scrolls of Individual Crystallites Schematic Diagram of the Crystal Structure of an Amphibole Fiber, Indicating the Unit Cell Based on X^Sig022 (OH)^ Asbestos Industry Structures Asbestos Products Industry Asbestos - Salient Statistics t U.S. Asbestos Demand, and Projected Trends to 2000 Possible Areas of Asbestos Deposits Asbestos Mines in the United States Quebec Production Trends, From Analysis of 1951 - 1970 Data Geographical Dispersion of U.S. Friction Materials Plants Dry-Mixed Brake Lining Manufacturing Operations Wet-Mixed Molded Brake Lining Manufacturing Operations Molded Clutch Facings Manufacturing Operations Woven Clutch Facings Manufacturing Operations 3 4 19 20 30 48 53 54 57 66 69 71 72 74 viii FNISl 04836 1.0 INTRODUCTION This study on the commercial market and environmental sources of asbestos was undertaken for the following reasons: (a) to consolidate the large volume of published literature in an attempt to describe the asbestos industry and the uses of asbestos in terms of marketing data and statistics; and (b) to examine the potential for asbestos emissions from final end-use products. Asbestos emissions from mining and milling operations and from industrial factories have been examined in reasonable detail by previous EPA reports. , However, no com prehensive attempt has been made to examine the sources and quantities of as bestos which may be released to the environment from asbestos-containing prod ucts. Unfortunately, because of limited funds, this report considers only the asbestos emissions from friction materials such as brake linings and clutches. 1 FMSI 04837 2.0 DESCRIPTION OF ASBESTOS 2.1 Composition and Properties of Asbestos "Asbestos" is not the name of a distinct mineral species but is a commerical term applied to fibrous varieties of several minerals differing widely in chemical composition, the fibers being diverse in length, strength, flexibility, and consequent usefulness (The Asbestos Factbook, 1970). The varieties of asbestos most used commercially are chrysotile, amosite, croci- dolite, and anthophyllite. Chrysotile, which accounts for approximately 95% of all asbestos consumed commercially, is of the serpentine group of fibers, while the other varieties (crocidolite, amosite, anthophyllite, tremolite, and actino- lite) are of the amphibole group of fibers. Among the amphibole asbestoses, amosite and crocidolite are the most important commercially; anthophyllite, tremolite, and actinolite account for only minor commercial consumption (Rover, 1976; Clifton, 1975). Sometimes the literature refers to the common asbestoses with jargon names: "white asbestos" for chrysotile and "blue asbestos" for crocidolite (Berger and Oesper, 1963). While the asbestoses differ in chemical composition, they share similar polymeric silicate structure. The fibrile-like structures of the asbestoses result from linear chains of silicate tetrahedra. Chrysotile and amphibole asbestoses fundamentally differ by the number and shape of the sili cate units. These differences can be visually identified from Figures 2.1 and 2.2, which are structure schematics of chrysotile and amphibole, respectively. Chrysotile consists of silicate units arranged in double layers and formed into a laminar structure. The chrysotile Si^O^ layers are joined by brucite (magnesium hydroxide) layers. This double layered structure is contorted in 2 FMSI 04838 Figure 2.1. ' Schematic Diagram of the Structure of a Chrysotile Fibre Formed of Several Scrolls of Individual Crystallites (Each scroll is formed from a closely connected double layer having magnesium hydroxide units on its external face and silica units on its inner face. The details of a small section of the scroll show the structure of the double layer and of the unit cell based on Mg3(Si205) (OH)4.) (Kover, 1976) 3 FMSI 04839 A247S8 Figure 2.2. . Schematic Diagram of the Crystal Structure of an Amphibole Fiber, Indicating the Unit Cell Based on X7Si8C>22 (0H)2 (The line k-A represents the edge of the preferred cleavage plane along which the fibres will split to form even smaller fibres.) (Kover, 1976) 4 FMSI 04840 tubes in which the brucite forms the outer fiber layer. The amphiboles contain silicate as Si.O,, double chains in a banded structure. The chains are united . 4 11 by intercalcated cations and form as solid fibers (Berger and Oesper, 1963; Badolette, 1963; Kover, 1976). Unlike the synthetic chemicals which usually exhibit unique chemical compositions, the asbestoses are composed of mixed inorganic oxides. The vari ous asbestoses are characterized by ranges of these oxides rather than precise molecular formulas. Table 2.1 below gives the approximate chemical formula for each of the varieties of asbestos, while Table 2.2 lists the typical ranges of mixed oxide compositions for the asbestoses and a few related minerals. Table 2.1. Approximate Chemical Formula of the Asbestoses (The Asbestos Factbook, 1970) Chrysotile Crocidolite Amosite Anthophyllite Tremolite Actinolite 3MgO 2Si02 2H20 Na20 Fe203 3FeO 8Si02 H20 1.5MgO 5.5FeO 8Si02 H2<D 7MgO 8Si02 H20 2CaO 5MgO 8Si02 H20 2CaO 4MgO FeO 8SiC>2 H20 Since asbestos is a metamorphic mineral, its composition reflects the composi tion of the surrounding minerals and its formation conditions. Therefore, the oxide composition range differs for asbestoses of different geographical origin, as evident from Table 2.3. The asbestoses contain relatively few elements. In 5 FMSI 04841 r i f i f L l l l l f L 1 I i I in m m in o sf <r cs cs co v> 00 cm rH ffi 1 in m vO m m o CS o cO 1 i--l cs cs rH rH o o o o in CO a> m <D o a O CM CO 00 43 r-l m m rH <r a> mo \D aJ U M !Z H sr H oO 1 oo ON u o >o JA \ u o cd O o cs rH co o1 1 1 iii CS i ! CS i--4 CO rH -4- CO <f 1 t 1 1 1 O rH 1 H rH rH 1 O rH 1 as CS o > u (o0 CO oGu CO 0) 00 g <d !- f-*ii (0 a CO o CM 3 On O 1 CO cs o oo m | H CO in m I 1 m m m cs cs rH CO 1 1 o rH l o o1 t <fr o1 ja P. H gQ fO o cs <D -4 o 1 cs in 1 o r-1 1 1 1 1 l mm 1 l CO o rH Os CO I l o1 oi 1 O \ O o1 OO m CM O og m CO CO O CO o CS cs o o1 CS 1 co H <r l sr CO cs -+ 1 co m H I m sr oI I vO o 1 cs o 1 m CO CO o vO cs o CO cs CS to m o\ 00 s o1 CO 1 I 010 1 m 1 rH o1 cs 1 cO 1 sJ- O rH cs rH CS CO CO <r CO CO CO O co sr o cs sr in m m in vO vO m . vO O i CO i a\ i o> i vO i rH 1 m o1 l o> 1 sf CO co *4- m m m vO CO ST cs CS H41 S H a) 4) u H H 4) 4J M H 0) rH 4J 4) 4) a 4) 41 oX rH rH >> rH u GM M O 4) JC! H *H 4) > O cu O rH CO H H o G O rH -O ao >> O UO CO C rH OuM go 4) H C rG M 4J rCl M e G U M CO O M O CJ < < < H H G* O 6 FMSI 04842 addition to silicate and water, they generally contain the oxides of magnesium, calcium, iron, and/or sodium. Aluminum and potassium oxides are sometimes present as trace "impurities." The "impurities" are defined as the oxides which are not accounted in the approximate chemical composition. They can either form part of the polymeric structure or occur as occlusions within the fibers (Berger and Oesper, 1963). Table 2.4 describes some of the properties important in the commercial uses of asbestos. The properties of asbestos that give it commercial value are its fibrous structure, the great strength of its fibers, and its resistance to high temperatures and to certain types of chemical attack. Chrysotile asbestos excels commercially due to its fineness of fiber, high flexibility, good heat resistance, general workability, and ample supply. The longer fibers can be spun easily into textile materials. However, chryso-- tile degrades faster than the amphiboles in water, acids, or alkalis. This results from the solubility and reactivity of the brucite. While amphiboles lose only ca. 9% of their weight in 4N HC1 after eight hours at 100C, chryso tile looses all magnesium hydroxide (60% of its weight) after only one hour in 1 N HC1 at 95C (Berger and Oesper, 1963). When chrysotile is extracted by the Soxhlet procedure for four hours with aqueous alkali (pH 10.33), it loses a high percentage of magnesium ion and yields magnesium silicate. Crocidolite, when treated by the same conditions, will leach only 4% silica and 6% sodium (Berger and Oesper, 1963). Because crocidolite and amosite fibers are highly acidresistant, they are particularly valuable for use in chemical plant applica tions. Anthophyllite and tremolite fibers are too brittle to be spun or used as fibrous reinforcements but, because of their resistance to attack by certain chemicals, are used for filtering purposes in chemical processing plants and in laboratories. 7 FMSI 04843 [ r CO r (o5 oCoO 4 i JOu0oS0, r& U r d0<Mu) Mh-4 or*s r Q o> sH O* o o [ CO u tn o 0o3_ uw Pm [ Q<0 J! co uo 0CO) i O 48 od (0 J-S> ro BO CJ i ucd 0) .c CJ l cn CM 0) rH HtO S3.8 FMSI 04844 Table 2.4. Physical, Chemical, and Mineralogical Properties of Varieties of Asbestos (Kover, 1976) Property Chemical formula pH Chrysolite M9jSi205(0H>4 Crocidolite Amosite Anthophyliit* Tremolite Actinolite Nd,Fe3SiB022(0H)2 (FeMgl7Si802j(0H)2 (FeMgljSijOj 2<;0H)2 Ca^Mg^SigOj 2(88)2 (CaM9FelsSi802 2(OH)2 9.2 to 99 -- Neutral -- -- Resiitinct to acids Vemng Poor Cross and ' slip libers Good Croea fiber -- Cross fiber -- Slip, mass fiber uooriented and interlacing Good SNp or mass fiber Good Slip or mass fiber Color Texture Green, 7ay, amber to white Soft to harsh, also silky Blue Soft to hath Luster Silky Silky to dull Hardness9 2.5 to 4.0 4 Gray, yellow to dark brown Coarse but somewhat pliable Vitreous, somewhat pearly 5.5 to 6.0 Yellowish brown, grayish white Gray-white, greenish, yellowish, bluish 4 Greenish Harsh Vitreous to pearly Generally harsh. sometimes soft &lky Hjrsh Silky 5.5 ta 6.0 5.5 6i Flexibility Spinnability High Very good Gcod Fair Good Fair Poor Poor Poor Poor Poor Poor Tensile strength, lb. in.* 824.000 876,000 max. 16.000 to 90.000 4.000 and i* 1.000 to 8,000 1,000 and less Fusion point, F 2.770 2.180 2,550 2,675 ,, 2,400 2.540 Specific heat, Btu/lb.F 0.201 0.193 0.210 0-212 0.217 forking Scale of Hardness: 1 - very easily scratched by fingernail, and has greasy feel to the hand; 2 - easily scratched by fingernail; 3 - scratch by brass pin or copper coin; 4 - easily scratched by knife; 5 - scratch with difficulty with knife; 6 - easily scratched by file; 7 - little touched by file, but will scratch window glass. All harder than 7 will scratch window glass. 9 FMSl 04845 Table 2.4 Physical, Chemical, and Mineralogical Properties of Varieties of Asbestos (Cont'd) Property Chrysotile Electric charge Filtration properties Positive Slow Specific ' gravity Cleavage 2.4 to 2.6 010 perfect Crocldolite Negative fm 3.2 to 33 110 perfect Amosite Negative Anthophyllite Negative Fnt Medium 3.1 to 335 2.65 to 3.1 110 perfect 110 perfect Tramolite Negative Medium Actinolite Nogstivt Medium 2.9 to 33 3.0 to 3.2 110 perfect 110 perfect Optical properties Biaxial positive, extinction parallel Refractive index 1.50 to 1.55 Biaxial + extinction inclined 1.7 plaochroic Biaxial positive, extinction parallel Biaxial positive, extinction parallel Biaxial negative, extinction inclined Biaxial negative, extinction inclined 1.64* 1.61* 1.61t 1.63* weakly pleochroic Resistance to destruction by heat Good, brittle at high temperatures Temperatura at ignition los$.F 1,600 Magnetic content,% Crystal Structure 0.0 to S O Fibrous and asbestiform Poor, fuses 1.200 3.0 to 5.9 Fibrous Good, brittle at temperature* 1.600 to i,aoo 0 Prismatic, lamellar to fibrous Very good Fair to good -- uoo 1.800 -- 0 0-- Prismatic, lamellar to fibrous - Long and thin columnar to fibrous Long and thin columnar to fibrous . Crystal * Monoclinic and system orthorhombic Monoclinic Monodtnic Mineralogical structure In veins of serpentine, etc. Fibrous in . iron stones Lamellar, coarse to fine fibrous and asbestiform Mineral association In altered peridotite adjacent to serpentine and limestone near contact with basic igneous rocks Iron rich silicious argillite in quartzose schists In crystollino schists, etc. Orthorhombic Monodinic Monoclinic Lamellar, fibrous asbestiform Long, prismatic and fibrous aggregates Rettcyuied long prismatic crystals and fibers In crystalline schists and gneisses In Mg limestones at alteration product of magnesian rocks, metamorphie and igneous rocks In limestones end in crystalline schists 10 FMSI 04846 Since asbestos is often used in the manufacture of insulation for electrical equipment, its electrical conductance is an important property. Its conductance is related to the magnetite ^6304) content. As the content of this impurity increases, the asbestos conductance also increases (Berger and Oesper, 1963). The thermal stability is limited by asbestos metamorphosis to other mineral forms. The fusion points listed in Table 2.4 are not melting points for the asbestoses, but correspond to the fusion temperature of the metamorphlc products. Chrysotlle, for example, is thermally transformed to the minerals olivine or enstatite at a rate dependent upon time and temperature. The trans formation may be important to assess some environmental losses for certain uses, such as in brake linings (Berger and Oesper, 1963). 2.2 Asbestos Grading Asbestos Is graded by fiber length. It is not commonly graded by mineralogical content or other properties. The Quebec Standard for chrysotile is the most important, because most asbestos consumed in the U.S. is graded by this system. The Quebec Standard measures the distribution of fibers after sieving a 16 ounce sample through a system constructed of four boxes: three screens and a "pan" for fines: Box Number Screen Opening Diameter of Wire 1 0.500" 0.105" 2 0.187" 0.063" (4 mesh) 3 0.053" 0.047" (10 mesh) Asbestos fibers are graded in nine groups: Groups No. 1 and 2 are hand-cobbled crudes and the remainder are milled fibers. Group No. 1 Is basically 3/4" staple and longer fibers, which makes the best spinning grade. Group No. 2 includes 11 FMSI 04847 i [ r spinning fibers of lower quality. The milled fibers are grouped according to i the box distributions listed in Table 2.5 (Berger and Oesper, 1963; The Asbestos Factbook, 1970). i Other grading systems are also used for chrysotile and the amphibole [ asbestoses. They also grade fibers by length. U.S. mined asbestos basically follows the Quebec Standard. Table 2.6 describes the modifications used for f Arizona and California mined asbestos. 2.3 Major Uses of the Asbestoses [ The following discussion briefly describes the major uses for the t asbestoses and the reasons why they are used. Market input/output data con cerning the quantities consumed according to use and grade are given in Sec tion 4.0. i 2.3.1 Chrysotile r Chrysotile dominates the asbestos consumed in total quantity, value, and number of products. It accounts for about 95% of all the asbestos [ commercially consumed. i (a) Asbestos Textiles The long chrysotile fibers (Grades No. 1, 2, and 3) are pre i dominantly used for textile manufacture. The textile products can eventually be marketed as textiles such as safety clothing, drapes and curtains, wicks, i etc. or they can be further processed with resins and other additives in the i manufacture of friction materials, gaskets, laminated plastics, etc. (Kover, 1976; Hendry, 1965; The Asbestos Factbook, 1970; Clifton, 1975). [ (b) Asbestos Cement i Medium sized chrysotile fiber (Groups No. 4 to 7) dominate in production of asbestos cement products (pipe and sheet). Asbestos cement i 12 FMSl 04848 Table 2.5. Chrysotile Grades by the Quebec Standard Test (The Asbestos Factbook, 1970) Standard Grade Designation Group No. 1, Crude No. 1 Group No. 2, Crude No. 2 Group No. 2, Crude run-of-mine Group No. 2, Crudes sundry Groups No. 3 through No. 9 Fiber Description - consists basically of crude 3/4" staple and longer - consists basically of crude 3/8" staple up to 3/4" - consists basically of unsorted crudes - consists of crudes other than above specified J - are "Milled Asbestos" Group No. 3: Group No. 4: Group No. 5 Guaranteed Minimum Shipping Test (Distribution of 16 oz. of Fibers) 3F 3K 3R 3T 3Z 4A 4D 4H 4J 4K 4M 4R 4T ' 4Z 5D 5K 5M 5R 5Z Box 1 10.5 7.0 4.0 2.0 1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Box 2 3.9 7.0 7.0 8.0 9.0 8.0 7.0 5.0 5.0 4.0 4.0 3.0 2.0 1.5 0.5 0.0 0.0 0.0 0.0 Box 3 1.3 1.5 4.0 4.0 4.0 6.0 6.0 8.0 7.0 9.0 8.0 9.0 10.0 9.5 10.5 12.0 11.0 10.0 8.6 13 Pan (fines) 0.3 0.5 1.0 2.0 2.0 2.0 3.0 3.0 4.0 3.0 4.0 4.0 4.0 5.0 5.0 4.0 5.0 6.0 7.4 FMSI 04849 Table 2.5. Chrysotile Grades by the Quebec Standard Test (Cont'd) Group No. 6 Group No. 7 Group No. 8 Group No. 9 Box 1 Box 2 Box 3 Pan (fines) 6D 0.0 0.0 7.0 9.0 7D 0.0 0.0 5.0 7F 0.0 0.0 4.0 7H 0.0 0.0 3.0 7K 0.0 0.0 2.0 7M 0.0 0.0 1.0 7R 0.0 0.0 0.0 7T 0.0 0.0 0.0 7W 0.0 0.0 0.0 11.0 12.0 13.0 14.0 15.0 16.0 16.0 16.0 8S under 50 lbs/cubic foot loose measure 8T under 76 lbs/cubic foot loose measure ' 9T over 75 lbs/cubic foot loose measure 14 FMSI 04850 Table 2.6. Modifications in Grading American Mined Asbestos (The Asbestos Factbook, 1970) ASBESTOS GRADES IN ARIZONA Source: Metate Asbestos Corporation, Globe, Arizona The same "Guaranteed Minimum Shipping Tests" are used in Arizona as are used in Canada, with the following exceptions: 3Z (Soft Filter Grade) is held to - 0 10 4 2 Special Sugar Grade LX-222-NAW is held to about Canadian Grade 3T 2 8 4 2 All other Arizona Grades follow Canadian grading procedures but add the following designations: . S H AW NAW Soft - Harsh - Acid Washed - Non-Acid Washed ASBESTOS GRADES IN CALIFORNIA Source: Coalinga Asbestos Company, Inc., Coalinga, California The following short Chrysolite asbestos fiber grades are available from Johns-Manville Corporation's Coalinga Mine at Coalinga. California. While the chemical composition of Californian fibers is very similar to that of Canadian Chrysotile. they arc typically lighter in color, lower in fines content and higher in surface area. Ul.TRABFSTOS Red Brand: ahigh surface area, high absorption, low fines general-purpose short fiber. ULTRABl-.STOS Blue Brand: a high quality, low fines sh >rt fiber somewhat similar to Canadian Grade 7R. This Grade is prepared es lecially for use in vinyl floor tile. ' Coalinga Floats an extremely short fiber having a minus 2(0 mesh content of approximately 95% by the McNeil test. (See page 23 for a description of this test.) Coalinga Paperbestns-100: an extremely short fiber prepared for Use in Ihc papermaking industry as a pitch control and pigment retention aid. Coalinga Asbattic a medium absorption short liber I'or uspliall paving applications. 15 FMSI 04851 products account for the major portion of the asbestos consumption, both in ^tonnage of fiber and market value. The properties which contribute to its commercial position include fiber length and tensile strength (Kover, 1976; Carton, 1974; Berger and Oesper, 1963; Clifton, 1976). (c) Asbestos Paper and Felt Properties for which chrysotile is used in this product segment include its capacity for heat and electrical insulation, its chemical and thermal stability, its strength and flexibility (Kover, 1975; Carton, 1974; Hendry, 1965). Chrysotile grades from 3 to 7 are predominantly used (Berger and Oesper, 1963; Clifton, 1975). (d) Composition Materials The composition materials include plastics, asbestos-vinyl and asbestos-asphalt products, coatings, and compounds. Chrysotile is added to these products generally as a filler and reinforcement medium (Modlc and Barsness, 1965; Seymour, 1968; Grove and Rosato, 1967). The longer fibers (including Grades No. 1 and 2) are used in the production of high grade laminated plastics. The short fibers (Grades No. 4 and shorter) dominate in the manufacture of most other composition materials (Clifton, 1975; Berger and Oesper, 1963). Although the quantity of fibers used in these products is large (the second largest consumption of fibers), the low value of the short fibers results in a low commercial value for asbestos used in this market segment. (e) Friction Materials The properties for which asbestos is used in friction materials include its capacity for thermal stability, its ability to act as a reinforcing agent, as a filler, for the regulation or inhibition of resin flow, its lower 16 FMSl 04852 abrasion than other fillers of its price range, and its dispersion of metal chips and other particulates (Hendry, 1965). While the fiber lengths of Grades No. A to 7 dominate the friction materials, some longer fibers are also used (Clifton, 1975). (f) Packing and Gaskets Chrysotile use in packings and gaskets is accounted for by its strength, resiliency, durability, toughness, and thermal stability (Hendry, 1965; Kover, 1976). Fiber length predominantly ranges from Grades No. A to 7, although some Grades 1 through 3 are also consumed (Clifton, 1975; Berger and Oesper, 1963; SRI, 197A). ' 2.3.2 Crocidolite Crocidolite fibers are shorter and more brittle than chrysotile but have a slightly higher tensile strength. Crocidolite is principally con sumed for the manufacture of asbestos cement products (Kover, 1976; Clifton, 1976). While it can be spun into fibers, its spinnability is not equivalent to chrysotile. Longer crocidolite fibers are sometimes mixed with chrysotile for textile production (Berger and Oesper, 1963). It is used as replacement for chrysotile fibers in some laggings, insulations, filter media, and packings exposed to corrosive (acid or alkali) substances (Fisher, 1967; Hendry, 1965; Kover, 1976). Long crocidolite fibers are also consumed in asbestos boards and papers (Berger and Oesper, 1963). 2.3.3 Amosite Amosite has lower tensile strength than chrysotile or crocidolite by more than an order of magnitude. It is consumed mainly in asbestos cement products. Other major uses are in various thermal insulations, including pipe and boiler coverings, bulkhead linings in ships, and 85% magnesia insulation (Hendry, 1965; Kover, 1976). 17 FMSI 04853 2.3.A Tremolite and Actinolite Both tremolite and actinolite are of low tensile strength and are brittle. They have only minor commercial use. They are primarily con sumed as cheap fillers and as filtering mediums. Tremolite is sometimes puri fied by acid treatment for special filtering purposes (Kover, 1976; Hendry, 1965) 2.3.5 Anthophyllite Anthophyllite is also of minor commercial value. It is mainly used as a filler in rubber, plastics, adhesives, and asbestos cement products (Kover, 1976; Hendry, 1965; Clifton, 1975). 18 FMSI 04854 3.0 DESCRIPTION OF THE ASBESTOS INDUSTRY 3.1 Industry Structure Figure 3.1 below is a simple illustration showing the movement of asbestos within the asbestos industry. Mining------------- Hilling------------ Primary------------ Secondary--------- Consumer Industries Industries Industries 1------------Consumer Industries . Figure 3.1. Asbestos Industry Structure The following definitions have been adopted (Daly et al., 1976): Primary Industries: those industries that start the manufacturing process with raw asbestos fiber and modify the fiber to produce an intermediate product (to be further processed or fabricated) or a finished product. Secondary Industries: those industries that continue the manufacturing process with an intermediate asbestos product (one in which the fiber has previously been modified in a primary industry), and further process, modify, or fabricate it to produce either another intermediate product (to be further processed or fabricated) or a finished product. Consumer Industries: those industries that purchase a finished asbestoscontaining product (from a primary or secondary industry), and apply, install, erect, or consume the asbestos-containing product without further physical modification of the product. This classification is depicted in Figure 3.2, which categorizes the various end uses by products. 19 FMSl 04855 I \i i i i r [ |i li ji [ L |l c4n> j( h 3Vi -ca >4 iS UJ cooc u-I. oC/J 2 u < Doococ Ol. zo pu 5 <3 Z 2 < U CoC H Z o M g H O DC UaJ. < kE 3 u. < 8 f2 li 20 kD o\ H o| l nj O 4uJ 3 MC O *3o ol-i 04 O at s < CM CO uV3Oi) 0M3) 00 PHm UJ 2 fN\S\0A56 The first industry segment to come into contact with the asbestos is, of course, the mining segment. As far as the United States is concerned, how ever, this predominately occurs in Canada. From 1971 to 1975, between 80-85% of the asbestos consumed domestically was imported (see Sections 4.3 and 4.4); and of the imported asbestos, nearly 96% originated in Canada (Clifton, 1975). The milling segment of the industry is very closely connected to the mining segment because mills are usually located in close geographical proximity to the mines and, in general, the mines and mills are owned and operated by the same parent corporation. American mining and milling production is discussed in Section 5.1. The interesting relationship is, however, the relationship between the mining segment of the industry and the primary industries, the product manu facturers who initially fabricate asbestos products. Table 3.1 lists the cap tive fiber sources in Canada and in the U.S. for the major domestic asbestos products manufacturing firms. Twenty of the largest U.S. asbestos products manufacturers are listed in Table 3.2. When Tables 3.1 and 3.2 are compared, it can be seen that four corporations (Johns-Manvilie, Raybestos-Manhattan, Jim Walter, and ASARCO) not only control large mining interests in Canada, but also control nearly 35% of the American asbestos products market. According to the 1967 U.S. Census of Manufacturers, 81 firms operating 138 establishments were involved in asbestos products manufacturing (SIC 3292; this does not include asbestos paper-making establishments). The 1972 Census of Manufacturers lists 142 establishments for SIC 3292. When the asbestos papermakers are included, it is estimated that approximately 85 firms are presently engaged in asbestos products manufacture (SRC estimate). In evaluating the asbestos products manufacturing industry, it is possible to arrive at the 21 FMSI 04857 Table 3.1. Captive Fiber Sources for the Major American Asbestos Product Manufacturing Firms (Igwe, 1974; Asbestos Magazine, Dec. 1975) Company Canadian Mines Mine (Company) Fiber-Producing Capacity (short tons/year) ASARCO Lake Asbestos of Quebec, Ltd. Johns-Manville Products Corp. Canadian Johns-Manville Co., Ltd. Jim Walter Corp. Carey-Canadian Mines, Ltd. Raybestos-Manhattan, Inc. Cassiar Asbestos Corp. (partial interest) General Dynamics Corp. Asbestos Corp., Ltd. (54% interest) 150,000 835,000 200,000 110,000 500,000 Atlas Asbestos Co. Union Carbide Corp. Johns-Manville Products Corp. American Mines Atlas Asbestos Co. Union Carbide Mines Coalings Asbestos Co. 25,000 10,000 (closed at present) 22 FMSI 04858 Table 3.2. Twenty of the Largest U.S. Asbestos Product Manufacturers (Economic Information Systems, 1976; Igwe, 1974; SRC Estimates) Company Estimated 1975 Asbestos-Product Sales ($ millions) 1. Johns-Manville Corp. 2. Raybestos-Manhattan, Inc. 3. GAF Corp. 4. Bendix Corp. 5. Jim Walter Corp. (Celotex) 6. Armstrong Cork Co. 7. Illinois Central Industries (Abex Corp.) 8. Flintkote Co. 9. Asten-Hill Mfg. Co. 10. H.K. Porter Co. 11. Certain-Teed Corp. 12. Nicolet Industries 13. Kentile Floors Inc. 14. National Gypsum Co. 15. Royal Industries 16. Uvalde-Rock-Asphalt Co. 17. Sabine Industries 18. American Asbestos Textile 19. ASARCO Inc. (Cement Asbestos Products) 20. Gatke Corp. 240 140 114 72.5 71 60 60 50 40.5 37.6 33.1 30.7 29.5 27.1 24.5 21.6 21.6 15.0 13.0 11.6 Approximate Percentage of the U.S. Market 18.0 10.5 8.5 5.5 5.5 4.5 , 4.5 3.5 3.0 3.0 2.5 2.0 2.0 2.0 2.0 1.5 1.5 1.0 1.0 1.0 23 FMSI 04859 conclusion that the industry may be dominated by several giant firms. From Table 3.2 it can be seen that the six largest firms control over 50% of the 4 market. It should also be noted that the larger asbestos-based manufacturing firms are generally diversified into other product lines. Table 3.3 shows the percentage of some major manufacturers' product lines that are related to asbestos. Table 3.3. Asbestos-Based Activity of Some Major Asbestos-Manufacturing Companies (Igwe, 1974; SRC Estimates) Company Estimated Annual Sales ($ millions) American Biltrite Rubber Co. The Flintkote Co. GAF Corp. Johns-Manville Corp. National Gypsum Co. Jim Walter Corp. 161 441 800 519 880 Percent of Product Line Related to Asbestos 5 12 5 30 5 8 3.2 Types of Plants Asbestos products manufacturing plants are characterized by a high degree of specialization. The typical plant (especially of the minor manufac turers) is apt to be a single-product operation whose product is geared to service a specific industry. Table 3.4 lists the general statistics for 24 FMSI 04860 Table 3.4. Industry Specialization and Primary Product Class Specialization for Asbestos Product Producing Establishments: 1972 (SIC 3292) (1972 Census of Manufacturers, U.S. Bureau of the Census) Establishments Establishments with 75% or More Specialization Entire Industry Primary Product Class Friction Materials Asbestos-Cement Shingles and Clapboard Vinyl Asbestos Floor Tile Asbestos and Asbestos-Cement Products 142 23 7 18 55 127 21 6` 17 42 establishment specialization in 1972. In Table 3.4 the measures of plant specialization are shown as: (1) industry specialization - the ratio of primary product shipments to total product shipments (primary plus secondary) and (2) product class specialization - the ratio of the largest primary product class shipments to total product shipments (primary plus secondary) for the establishment. A survey of selected facilities shows that nearly all the large plants employing in excess of 100 workers belong to the major firms within the industry, such facilities also often generating relatively minor proportions of non asbestos products (Igwe, 1974). 25 FMSI 04861 It is fair to state that the asbestos manufacturing industry in the United States is very mature, with most of the larger plants well over 25 years old and employing well-established technologies. For instance, asbestos-cement pipe manufacture was introduced in the United States about 1928 by the JohnsManville Corporation at its Waukegan, Illinois, plant. Except for incorporation of sophisticated controls and materials handling systems, it is doubtful whether the technology, similar in principle to that employed in the manufacture of flat or corrugated sheeting, has changed to any fundamental extent since then. Simi lar comments may be applied to the manufacture of vinyl asbestos tiles (Igwe, 1974) 3.3 Numerical and Percentage Distribution of Plants, Employees,'and Production The numerical distribution of the establishments by size (expressed in terms of the number of employees) as given by the 1972 Census of Manufacturers is shown in Table 3.5. Total employment as a function of establishment size and total value of shipments as a function of establishment size for asbestos products manufacturing are given in Tables 3.6 and 3.7, respectively. A comparison of Tables 3.5 and 3.6 shows that whereas establishments with less than 100 employees account for 53.4% of the number of asbestos prod ucts manufacturing establishments, these facilities employ only 7.8% of the work force. The relative minor contributions of the nless-than-100-employees" facilities are further illustrated when Table 3.5 is compared to Table 3.7. The industry segment with less than 100 employees per establishment contributes only 6.1% of the shipment values of asbestos products. The economic punch appears clearly to rest with the major manufacturing units. There is the additional consideration that, for a given asbestos product, the manufacturing equipment tends to be of a given standard capacity. 26 FMSI 04862 Table 3.5. Asbestos Products Manufacture: Distribution of Plant Sizes (1972 Census of Manufacturers (SIC 3292), U.S. Bureau of the Census) Average Number of Employees 1 to 4 5 to 9 10 to 19 20 to 49 50 to 99 100 to 249 250 to 499 500 to 999 1000 to 2499 Total Total Number of Establishments 12 20 13 16 15 40 19 5 2 142 Percent of Total 8.5 14.0 9.1 11.3 10.5 28.2 13.4 3.5 1.4 Table 3.6. Asbestos Products Manufacturing: Total Employment as a Function of Size of Facilities (1972 Census of Manufacturers (SIC 3292), U.S. Bureau of the Census) Average Number of Employees 1 to 4 5 to 9 10 to 19 20 tor 48 50 to 99 100 to 249 250 to 499 500 to 999 1000 to 2499 Total . * SRC Estimates Total Number of Establishments 40* 100 200 500 1,100 6,400 6,300 6,300 4,200* 25,140 Percent of 0.2 0.4 0.8 2.0 4.4 25.4 25.0 25.0 16.7 27 FMSl 04863 !*Table 3.7. Asbestos Products Manufacturing: Total Value of Shipments as a Function of Size of Facilities (1972 Census of Manufacturers (SIC 3292), U. S. Bureau of the Census) Average Number of Employees 1 to 4 5 to 9 10- to 19 20 to 49 50 to 99 100 to 249 250 to 499 500 to 999 1000 to 2499 Total * SRC Estimate Value of Shipments ($ millions) 0.7 4.9 7.4 15.8 30.7 246.8 255.6 201.5 200.0* 963.4 Percent of Total 0.5 0.8 1.6 3.2 25.6 26.5 20.9 20.8- Differences in plant capacities are therefore determined approximately by the number of installed machines, and capacity differences therefore occur in multi ples of one standard machine capacity (Igwe, 1974). 28 FMSI 04864 4.0 MARKET INPUT/OUTPUT DATA The salient statistics for asbestos are graphed in Figure 4.1, which covers the period from 1940 to 1975. Import and export data shown in Figure 4.1 repre sent shipments of unmanufactured asbestos only. 4.1 Mine Production Table 4.1 lists the domestic and world mine productions from 1965 to 1975. U.S. mines shipped only 75% as much asbestos in 1974 as in 1973 and only 66% as much in 1975 as in 1973. The exact total output of 112,533 tons in 1974 was valued at $13,759,000 (Clifton,1975). _ Only four states produce asbestos: California, with 53% of the 1974 total, was the leader, followed in order by Vermont, Arizona, and North Carolina. The California segment of the asbestos industry has led the sharp decline in U.S. production. The closing, in early 1974, of Johns-Manville's (Coalings Asbestos Co.) mine was followed by the closing of H.K. Porter's (Pacific Asbestos Corp.) mine. These mine closures led to production of only 57% of the 1973 California state total, and only 55% of the 1973 dollar value of the fiber was realized (Clifton, 1975). The H.K. Porter mine was sold in October, 1975, to Calaveras Asbestos Ltd. and was to begin operation in mid-1976 (Asbestos Maga zine, December, 1975). All of the American mines produce the chrysotile variety of asbestos except the North Carolina mines which produce the anthophyllite variety. In total, the American mines produce approximately 15% of the asbestos used in the United States. The remainder is imported, mostly from Canada (see Section 4.3). 29 FMS1 04865 614750 THOUSANDS OF SHORT TONS Figure 4.1. Asbestos - Salient Statistics (SRI, 1974; Clifton, 1974; U.S. Bureau of the Census, 1975 a, b) 30 FMSI 04866 F [ [ [ L [ l L m o\rH u*> n Or-' O' a a) f <a<uy P *accNHji bO 5 o CDO ,0 3 m on u0O CO 4oJ CO &CD O ao N ao Q'OO' r4 O' nO3j O 0U4 iH 01 VI <1* Ha) *fB3l hO *>4oeo-4 *oH U*a U 05 S H 31 FMSI 04867 4.2 Exports Table 4.2 below lists the American export of asbestos (unmanufactured) from 1965 to 1975. Table 4.2. U.S. Export of Asbestos (Unmanufactured) for 1965 - 1975 (Clifton, 1975; U.S. Bureau of the Census, 1975 b) . Year 1975 1974 1973 1972 1971 1970 1969 1968 1967 1966 1965 Asbestos Export in Thousands of Short Tons 35 62 66 59 ' 54 47 36 41 47 47 43 Tables 4.3a and 4.3b list the countries to which the exported asbestos (unmanufactured) was shipped in 1975 and in the first half of 1976, respective ly, and the amounts shipped to each country. Unmanufactured asbestos includes asbestos fibers, not further processed than beaten, washed or graded to length and asbestos waste and refuse. Table 4.4 lists U.S. exports, by country, of asbestos manufactured products in 1975. In 1975 U.S. exports of unmanufactured asbestos amounted to only 6.5% of the quantity of U.S. imports, while in 1974 the figure was only 8.1%. On the other hand, the dollar value of U.S. exports of manufactured asbestos prod ucts was nearly three times higher than the dollar value of U.S. imports of manufactured asbestos products. 32 FMSI 04868 Table 4.3a. U.S. Export -- By Country -- of Asbestos (Unmanufactured) in 1975 (U.S. 3ureau of the Census, 1975 b) 2764015 Asbestos fibers, not further processed than beaten washed, or graded to length Net Quantity Value (Short Tons) (Dollars) Canada Mexico Brazil Belgium France West Germany Rumania Iran Singapore Japan Other Countries Total 1,567 6,881 699 463 206 937 494 721 1,137 1,334 ' 734 15,173 682,546 2,349,846 261,080 140,181 204,242 335,709 101,420 252,817 523,255 936,115 279,895 6,067,106 2764030 Asbestos waste and refuse Canada 3,629 Mexico 5,109 Colombia 706 Venezuela 391 Brazil 115 United Kingdom 815 France 458 West Germany 723 Italy 120 Iran 203 Singapore 615 Japan 3,842 Egypt 104 Other Countries 2,918 Total 19,748 188,856 1,151,572 124,078 70,978 67,123 131,681 101,436 202,087 72,414 78,240 577,569 700,350 64,558 460,943 3,991,885 U. S, Bureau of the Census, 1975b 33 FMS1 04869 Table 4.3b. U.S. Export -- By Country -- of Asbestos (Unmanufactured) from January, 1976, to June, 1976 (U.S. Bureau of the Census, 1976 b) 2764015 Asbestos fibers, not further processed than beaten, washed, or graded to length Net Quantity (Short Tons) Value (Dollars) Canada Mexico Venezuela Brazil United Kingdom The Netherlands Belgium East Germany Greece Rumania Iran Thailand Indonesia Taiwan Japan Algeria Other Countries Total 448 4,883 119 63 41 298 328 177 126 371 140 1,320 900 300 1,532 840 595 12,481 161,298 1,283,987 40,302 41,106 32,000 63,953 76,115 130,190 33,840 101,135 39,033 527,987 284,150 116,350 631,900 292,428 104,760 3,960,534 2764030 Asbestos waste and refuse Canada Mexico Colombia Venezuela Brazil United Kingdom East Germany Spain Italy Rumania United Arab Emirants Korean Republic Japan Algeria Libya Other Countries Total h U. S. Bureau of the Census, 1976b 255 5,430 445 231 378 613 400 120 49 400 192 1,500 3,507 760 149 646 15,075 63,389 1,113,082 80,832 36,805 77,447 114,365 209,904 57,831 54,279 76,000 125,195 348,000 546,306 57,054 101,058 158,559 3,220,106 34 FMSI 04870 * Table 4.4. U. S. Exports--By Country--oE Asbestos Manufactured Products in 1975 6618310 Asbestos-cement shingles and clapboard Net Quantity (Pounds) Value (Dollars) Canada United Kingdom West Germany Italy Saudi Arabia Japan Other Countries Total ' 669,126 589,890 17,778,767 7,205,759 228,577 234,704 1,847,108 28,553,931 142,466 109,149 2,977,698 943,314 7S.228 66,185 331,776 4,648,816 6618320 Articles of asbestos-cement or of fiber--cement except cement shingles and clapboard Canada Mexico Salvador Panama Brazil Sweden West Germany Iran Saudi Arabia Indonesia Philipine Republic Japan The Pacific Islands Algeria Republic of South Africa Other Countries Total 21,936,513 487,372 455,804 5,266,390 134,606 305,303 102,004 265,941 4,511,035 33,478 360,441 418,104 320,865 2,094,038 116,300 1,096,502 37,904,696 3,867,321 138,980 64,879 715,851 70,184 375,555 87,175 79,733 999,724 161,793 70,893 242,323 71,806 185,964 73,093 422,609 7,627,883 6638105 Asbestos gaskets 1 Canada Jamaica Iran Saudi Arabia Republic of South Africa Other Countries Total 172,100 32,955 39,551 91,663 14,105 184,962 535,336 500,993 98,785 68,213 202,404 79,183 660,608 1,610,186 itu. s Bureau of the Census, 1975b 35 FMSI 04871 Table 4.4. U. S, Exports--By Country--of Asbestos Manufactured Products in 1975 (Cont'd) Net Quantity Value (Pounds) (Dollars) 6638115 Asbestos packing 2 Canada Mexico Guatemala Jamaica Colombia Venezuela Surinam Peru Chile Brazil 1 Sweden Finland United Kingdom Ireland The Netherlands Belgium France West Germany Switzerland Spain Italy Greece Iran Israel Kuwait Saudi Arabia India Pakistan Thailand Singapore Philippine Republic Korean Republic Taiwan Japan Australia New Zealand Nigeria Republic of South Africa Zambia Other Countries Total * U. S. Bureau of the Census, 1975b 1,042,869 393,093 25,828 49,803 320,649 37,695 42,645 151,358 123,234 114,892 15,451 30,289 264,110 81,400 15,083 20,239 41,189 76,187 17,857 30,531 86,309 25,198 46,118 9,577 16,468 466,441 145,126 13,920 42,989 153,448 229,895 27,000 52,596 57,871 28,394 25,210 33,470 35,719 11,917 346,981 4,749,049 1,896,802 291,741 68,294 278,425 513,348 158,526 142,790 396,141 205,258 119,524 94,047 279,984 374,256 366,739 113,214 139,314 177,591 205,023 80,840 183,812 673,373 73,157 137,128 95,091 80,943 256,331 64,691 64,832 76,663 408,972 551,008 63,030 159,405 262,573 131,979 170,069 87,997 242,818 - 118,528 987,008 10,791,265 36 FMSI 04872 Table 4.4. U. S. Exports--By Country--of Asbestos Manufactured Products in 1975* (Cont'd) Net Quantity (Pounds) Value (Dollars) 6638117 Asbestos insulation, heat or sound 2 Canada Mexico Dominican Republic Venezuela Surinam Peru Brazil United Kingdom The Netherlands Belgium Iran Pakistan Singapore Philippine Republic Mainland China Japan Australia New Zealand Egypt Ghana Other Countries Total -- -- -- -- -- -- -- .-- -- -- -- -- -- -- -- -- -- -- -- -- -- " 729,888 188,096 60,990 282,149 282,149 81,658 214,532 130,610 - 102,618 253,755 66,323 143,518 364,906 74,620 916,153 98,572 99,706 248,444 68,333 65,383 812,154 5,071,672 3120 Asbestos textiles and yarns 3 Canada Mexico Peru Sweden United Kingdom Ireland The Netherlands West Germany Italy Japan Australia Other Countries Total 7,749,305 1,249,110 122,520 122,929 85,929 45,100 487,222 195,984 54,043 23,646 1,020,703 307,061 11,463,552 * U. S Bureau of the Census, 1975b 3,664,189 747,770 220,267 230,746 207,598 145,350 127,799 252,944 274,700 146,510 614,452 651,974 7,284,299 37 FMSI 04873 Table 4.4. U. S. Exports--By Country--of Asbestos Manufactured Products in 1975* (Cont'd) Net Quantity Value (Pounds) (Dollars) 6638150 Asbestos protective clothing Mexico Greece Saudi Arabia . Other Countries Total -- -- -- -- -- 76,580 200,311 68,643 463,975 809,509 6638160 Asbestos manufactures other than friction materials, NEC Canada Mexico Panama Jamaica Venezuela Peru Chile Brazil Sweden ' United Kingdom The Netherlands West Germany Switzerland Poland Lebanon Iran Saudi Arabia Korean Republic Japan Australia New Zealand 1 Republic of South Africa Other Countries Total 2,230,745 246,573 74,099 70,179 749,761 305,139 182,659 83,043 I,145,722 2,528,018 702,650 866,848 124,542 81,315 83,372 66,238 185,369 110,313 439,217 92,913 200,613 325,572 845,089 II,739,989 *u S. Bureau of the Census, 1975b 38 FMSI 04874 Tabla 4.4. U. S. Exports--By Country--of Asbestos Manufactured Products in 1975* (Cont'd) Net Quantity (Pounds) Value (Dollars) 6638202 Asbestos clutch facings for automotive use, including linings Canada Chile United Kingdom . West Germany Other Countries _______ Total 506,277 63,447 195,978 226,888 281,518 1,274,108 6638206 Asbestos clutch facings, NEC, including linings Canada Other Countries Total 160,905 163,144 324,049 6638215 Asbestos brake linings for automotive use 1 Canada Guatemala Ecuador Chile Belgium Greece Lebanon Iran Singapore Indonesia Other Countries Total 5,726,553 55,287 76,894 26,188 83,388 426,808 ; 146,100 164,803 133,140 118,415 700,518 7,658,094 4,681,018 95,364 114,637 63,495 133,965 177,068 165,735 156,894 82,093 73,897 869,554 6,613,702 6638225 Asbestos brake linings, NEC 6 Canada Mexico Brazil The Netherlands Japan Australia Other Countries Total__________________ U. S. Bureau of the Census, 1975b 1,487,000 274,572 20,913 26,700 15,909 48,975 180,307 2,054,376 1,594,737 173,896 148,892 271,849 64,690 136,347 369,465 2,759,876 39 FMS1 04875 4.3 Imports Table 4.5 below lists the American imports of asbestos (unmanufactured) from 1965 to 1975. Table 4.5. U.S. Imports of Asbestos (Unmanufactured) for 1965 - 1975 (Clifton, 1975; U.S. Bureau of the Census, 1975 a) Year 1975 1974 1973 1972 1971 1970 1969 1968 1967 1966 1965 Asbestos Import in Thousands of Short Tons 539 . 766 792 736 682 649 695 737 646 720 719 ' In 1975, 539,000 short tons of asbestos were imported into the U.S., as compared to 766,000 short tons in 1974. The decrease from 1974 to 1975 was due to a shortage of asbestos in the Canadian supply caused by: 1) a destruc tive fire at Thetford Mines, Quebec, 2) a landslide at Johns-Manville's Jeffrey Mine, Quebec, and 3) the 7-month-long strike of Quebec asbestos workers (Asbestos Magazine, December, 1975). During the first half of 1976, 329,000 short tons of asbestos were imported, a rate which is approximately midway between the 1974 and 1975 figures. . 40 FMSI 04876 Tables 4.6a and 4.6b list U.S. imports, by country, of unmanufactured asbestos In 1975 and the first-half of 1976, respectively. Table 4.7 gives similar data for 1973 - 1974. Table 4.8 lists U.S. imports, by country, of manufactured asbestos products in 1975. A historical breakdown for asbestos imports of chrysotile, crocidolite, and amosite is included in Table 4.9, Asbestos Supply-Demand Relationships. During the entire history of the asbestos industry in the U.S., domestic sources have been able to meet only a small percentage of U.S. require ments. Canada furnished 96% of all the asbestos tonnage imported by the U.S. (1969 - 1973), but only a small portion (3%) was spinning grade fibers. The comparatively small tonnages imported from Africa are more important than would appear on a tonnage basis because they consist largely of special kinds and qualities unobtainable elsewhere (Clifton, 1975). 4.4 Supply-Demand-Use Table 4.9 gives the asbestos supply-demand relationships for 1965 - 1974. The U.S. supply is a combination of imports, domestic mine pro duction, industry stockpiles, and governmental stockpile releases. The U.S. supply is distributed among industry and governmental stockpile acquisitions, exports, and industry demand. The relative importance of each is apparent from Table 4.9. 'The asbestos distribution by end use, grade, and type for 1974 is shown in Table 4.10. The major buyers of asbestos and asbestos ore are listed in Table 4.11. , 4.5 Asbestos Fiber Prices Asbestos prices are characterized by an erratic price history. Prices for Canadian asbestos increased about 8% in 1973, 39% in 1974, and 23% in 1975. 41 FMSI 04877 Table 4.6a U.S. Imports--by Country--of Unmanufactured Asbestos In 1975 Net Quantity Short Tons Customs Value (dollars)** F.a.s. C.i.f. 2764010 Asbestos, Amoslte Rep SAF ToCal 3,894 3,894 1,539,951 1,539,951 1,542.143 1,542,143 1,872,035 1,872,035 2764020 Asbestos, Crocidolite, Blue Mozambq Rep SAF ToCal 118 11,570 11,688 16,090 4,942,886 4,958,976 16,090 4,942,181 4,958,271 29,033 6,100,733 6,129,766 2764030 Asbestos, Chrysotile Crudes Canada U King Belgium USSR Rep SAF Swazlnd Rhodesia Total 71 277 22 4,525 940 2,756 1,633 10,244 9,045 82,982 2,670 920,772 663,658 952,544 1,521,421 4,153,092 9,654 82,982 2,670 920,772 663,658 952,544 1,520,611 4,152,891 9,654 121,299 4,408 1,617,748 760,556 1,291,259 1,753,361 5,558,285 . 2764040 Asbestos, Chrysotile, Except Crudes and Spinning Fibers Canada Rep SAF Rhodesia local 7,637 115 382 8,134 5,772,397 99,572 368,845 6,240,814 5,879,920 99,572 368,845 6,348,337 5,893,666 109,296 414,831 6,417,793 * 27640S0 Asbestos, Chrysotile, Except Crudes and Spinning Fibers Canada Mexico U King USSR Italy Gaza SC Rep SAF Rhodesia Total . 2764060 490,615 73 58 86 44 152 220 32 491,280 91,014,320 14,876 11,396 38,640 12,540 25,914 68,025 22,871 91,208,582 96,411,691 14,876 11,890 39,805 12,540 25,914 68,276 22,871 96,607,863 96,526,478 14,876 11,890 40,214 16,461 25,-914 95,123 27,614 96,758,570 Asbestos, Unmanufactured, Crudes, Fibers, Stucco, Etc., NES Canada Finland Belgium USSR Italy Rep SAF Rhodesia Total 5,222 329 48 5,768 153 1,237 576 13,333 776,931 32,841 4,599 1,321,982 23,868 391,099 357,486 2,908,806 858,340 32,298 4,599 1,321,982 23,868 424,487 357,486 3,023,060 859,639 51,915 7,426 1,822,332 38,805 533,022 473,331 3,786,470 Source: U.S. Bureau of the Census, 1975a **Customs Value: Value of Imports appraised by U.S. Customs Service. F.a.s. Value: Transaction value of imports at foreign port of exportation. C.i.f. Value: Value of Imports at the first port of entry In U.S. 42 FMSI 04878 Table 4.6b. U.'S. Imports--by Country--of. Unmanufactured Asbestos, January to June, 1976* Net Quantity Short Tons Customs Value (dollars) F.a.s. C.i.f. 2764010 Rep SAF Oth Cty ' Total 2764020 . Rep SAF Total 2764030 Canada Mexico U Kin* Rep SAF Rhodesia Total 2764040 Canada Total 2764050 Canada Fr Germ Rep SAF 0th Cty Total 2764060 Canada Fr Germ USSR Rep SAF Oth Cty Total Asbestos, Amosite 1,151 20 1,171 503,663 469 504,132 509,697 669 510,366 642,607 669 643,276 Asbestos, Crocidolite, Blue 4,712 4,712 2,315,466 2,315,46b 2,388,971 2,388,971 2,606,013 2,606,013 Asbestos, Chrysotile Crudes 289 234 119 351 1,095 2,088 125,175 125,486 55,992 193,918 1,115,230 1,615,801 129,108 126,948 55,992 193,913 1,115,230 1,621,196 129,108 126,948 64,090 220,191 1,200,965 1,741,302 Asbestos, Chrysotile Spinning Fibers 2,394 2,394 2,053,568 2,053,568 2,110,240 2,110,240 2,111,611 2,111,611 Asbestos, Chrysotile, Except Crudes and Spinning Fibers 298,988 1,086 396 17 300,487 60,006,713 202,826 217,440 3,919 60,430,898 63,427,681 202,826 219,660 3,919 63,854,086 63,598,407 257,094 235,599 3,919 64,095,019 Asbestos, Unmanufactured, Crudes, Fibers, Stucco, Etc., NES 8,759 823 6,700 1,953 54 18,289 1,450,342 179,840 1,292,721 898,889 21,969 3,843,761 1,571,118 179,840 1,293,001 920,675 22,029 3,986,663 1,572,326 320,577 2,079,238 981,292 22,368 4,975,801 *Source: U.S. Bureau of the Census, 1976a 43 FMSI 04879 Table 4.7. U.S. Imports for Consumption of Asbestos (Unmanufactured) by Class and Country (Clifton, 1974) Year and country Crude (Includ ing blue fiber> Textile fiber Quantity Value Quantity Value (short (thou (short (thou tons) sands) tone) sand*) AU other Quantity Value (short (thou tons) sands) 1073 Canada , Finland________ _______ _ Germany, Weet_______ Guyana _____ _____ __ Italy ------- ----------------- -Malagasy, Republic ___ Mexico ___________ _____ Mozambique _ ____ ___ Panama Portugal_________ ______ Rhodeaia. Southern ___ South Africa. Republic of___ _____ Swaziland ______, Yemen _____ _ . _____ Yugoslavia __ _________ Total ............ ......... 1974 Brazil Canada Finland_______________ Germany, Weet________ Italy Mexico _________ _ Portugal _Rhodeaia Republic of _ U.S.S.R _______________ Total 1,991 79 _ _ 51 1397 22 _ 27 845 21.629 200 -- 24.795 423 4.510 122 -- 6.500 116 99 __ _ 1.717 20.807 480 -- 22.718 13 85 __ 1,010 5,157 381 -- 6.576 15,665 ., __ __ __ _ _ _ __ 8 130 -- 15,803 _16,020 __ _ __ ___ __ __ 1 73 .. -- 6.094 26.76_8 1 __ 4 66 __ -26.839 _ 10.416 .. 4 __ 2 16 10.438 746,988 1.027 __ 808 8 8 48 5 12 1 __ $86,449 93 _.. 8 8 1 7 1 11 <`> 8,427 __ 80 6 733 _ 11 a 751,875 87,820 20 712,228 657 1 _ 65 4 2 106,086 74 1 __ 11 _2_ 8,291 461 510 _. 123 716,607 106.808 * Leu than V6 unit. Total Quantity Value (short (thou tons) sands) 764.644 1.027 79 308 8 a 48 88 12 1 846 $92,866 9$ 21 8 8 1 V 28 n () 423 25,064 880 60 8 6.244 195 11 8 792,473 98.914 20 789.161S17 100 1 66 4 1.721 _2 116.614 74 86 4 11 2 1.012 23.664 480 451 6.688 361 123 766,164 123,822 44 FWISI 04880 Table 4.8. U.S. Imports--by Country--of Manufactured Asbestos Products In 1975* Net Quantity Pounds Customs Value (dollars) F.a.s. C.i.f. 6618340 Asbestos & Hydraulic Cement Articles NES Canada Mexico Guatmal Colomb U King Belgium W Germ Japan Aus tral Total 12,176,880 282,803 532,566 15,259,038 9,246 7,395,456 4,149,943 145,941 246,333 40,198,206 1,700,400 73,555 43,941 1,494,207 5,350 1,858,386 377,706 30,725 56,234 5,640,504 1,773,749 73,564 43,941 1,494,215 5,368 1,858,022 377,705 30,725 59,555 5,716,844 1,773,779 73,564 60,097 1,760,082 5,995 2,168,971 564,244 36,848 70,473 6,514,053 6638000 Canada Mexico Venez Brazil Sweden Norway Finland Denmark U King Nethlds Belgium France W Germ Switzld Spain Italy Yugoslv Greece India Phil R Kor Rep China T Japan Rep SAF Total Asbestos Articles, NES, and Asbestos Yarn, Sliver, Rope, Etc., With or Without Wire 3,988,524 2,624,027 40,381 841,938 128,742 6,369 8,499 12,780 4,373,180 11,139 32,774 137,475 1,282,955 6,187 495,545 156,022 17,664 1,140 5,261 1,000 257,256 1,094,659 1,149,464 119,527 16,792,508 4,010,223 2,478,821 40,381 831,938 128,721 6,369 8,499 12,189 4,380,595 11,139 32,795 137,897 1,278,071 6,187 495,545 156,022 17,664 1,140 5,261 1,000 244,970 1,075,207 1*135,904 119,527 16,616,065 4,019,687 2,617,067 42,674 872,701 142,887 7,749 9,149 12,594 4,794,464 11,578 35,867 147,444 1,346,141 7,168 531,694 172,358 19,251 1,226 5,919 1,555 255,633 1,154,996 1,228,451 120,127 17,558,380 *Source: U.S. Bureau of the Census, 1975a 45 FMSI 04881 >1 X a 4) g H g 3 4-1 3 4-1 CO TJ a o k M T3 0) rH H & a o /""V u CD Q U o * g CO O o 4J 4J 00 CO d 0) H ,Q j9 01 <5 cO t5 * c0 CO <D 01 d o 4j 4J X 01 3 rQ o 43 2 (0 CM 0) O V* 3 CO cq u 0) P*, to 3 w 3 H rH 4* 0) rH *0 c0 H x* o O CM SO o ON cn rH I-- o o o o> P^. vO rH Pd r^. U rH rH O CO Sf > o CM JQ CM O x 0) H H (0 O Px so O * vO cd n CD o U H > 4 X in 00 rH Stt CO cn H A rH O 00 IS VI PS vO cO rH iH ou rH O 3M oC0 rH opH ps <1 a &4 <r o PS u CD si- 3 4J CD pH CM 00 un vO 3 #s 3o CM pH rH o O 32 3 3 pO CO 4-1 3 rH 4J pH O cn o Oh vO O X vo o O ps to CO 4-1 o cd CO H Ph > PS 5 O st o O CM rH rH CM M 0) P4 fS p JoS m 4- * sf rH 4 CM Oh H vO VO O m PS 44 O P4 PS vO CM O rH 3 o J2 O vO 3 Pd CO PS to PS 3 o >4 M P3 O rH rH 6 0) s U Pi 0> rH 'O CO Ps 3 u 34 PS 01 o p 4) 3 4-1 pO Pi H CM 00 4-1 M 0) cd 0> <! >* a rH vD a (3 V4 O fH U CO <4* M H o> O rH o a cd rH o u m a> 4J cd P4 52 PS H VO > *H < n oa) 4-1 4-> 3 O St cn H o H CJ Cd Ml- s s o 25 >t D-t PS ps 00 O 00 u too Q3 Cl oCO V* *4* px 52 <0 M Vi 3O CO iH J3 o O PS cd PS PS c M 3 3 o 3 Cd PS 3 M N u 4J (S 3 PS S 4H U 3 H O 4J n cd fd O u >* cd S o 3 3 >> cd ri 4-1 4J O cn d *4 U cO f>s 4-1 * CD d to CJ 0) td W o CM o o CM 4J a) & PQ PS 0) p S5 M & rH rt A XS 3o 3 Vi H O rH fu o cd 3 cO PS s rH CJ a H M (U ca 3 a rH cn 4J 3 a* vo pH A X dj CM iH Vi 00 VO O <0 ps O as Vi . >4 V (U cn XV rH S 4 4J smo W rH 0) & PS oPS CJ oO <u rH M rH V4 4J 5 oX to H d0 CoO u 4-1 4-1 CO pH rH O U jj U u Q 52 i-H cm vO * & ao a) rH CO rH x a) CO 3 < rJ PS 3 O H U cd M O OM. OO X <u 4J pH PS Oh U o o CO u a 3 TJ o M 04 H3 01 H01 1 C H cd rH M P o o M 0) rO rO 3 PS <-s 0) w H H 0) e o 4-1 CO o o *4- PS o 3 FH PS a) *c H PS oo (U JJ o Al u a o3 'X3 rH a J2 ai o o CM O CM PS O H3 S O a 3 PS 34 P 4J cn M 4-1 cn CO rH 3 m H J9 M aCO) o Sm CM o -4* rH s t u PS H3 e* pX oO ao 0 3 rH 4J CO 3 W 0o0 m Xo w .n & o u pH 3 3O 4r-i 3 c M oO 3 3 3 W o PS o. V4 o o u rH rH iH >C 3 X1 cn 4J cn 4J yj M H f=4 M CO 3 3: CO rH rH ps & o o cn m CM p* cn 0 PS o o c SO H uw PS 4-S o o CO c *H 3 52 H CcOv X O 3 4J rH o3 33 30 PS o o CO CO 3 rH 60 u I) X td a60 iH sM O a i cn 3 M OO S5 pH PS O p vO CT PS op Oo e to H 3 H A 3 M aO aO VI jd a> 00 Vi 4n-4 3o pO Pd CO H Vi pq PS s a c M 3 3 M M 3 ,C a 3 X 01 o u 3 3 rH o 3 O cd > S CM 2 3 C JJ p. 4-1 pd O p 3 4-1 CJ O O CJ cn o3 r cn cn M to c opH s eo cd cn cn >4 CO <0 s X X o 34 PS cn P P 47 FMSI 04882 Table 4.12 lists the average annual asbestos price from 1954 to 1974 and com pares it to a figure based on constant 1973 dollars. Table 4.13 lists recent prices for various grades and origins of asbestos. The remarkable disparity of grade prices is evident from Quebec chrysotile fiber prices. Grade No. 7 (shorts) was priced at $89 per ton, while Grade No. 1 (crudes) cost $3496 per ton. 4.6 Future Outlook The best projections for future use of asbestos are reported by Clifton (1975). The information and projections contained in this subsection come directly from Clifton (1975). The domestic demand for asbestos is expected to increase at a slow rate; the low rate of annual growth is expected to be 0.9%, while the high rate is expected to be 3.0%. The U. S. demand for asbestos in the year 2000 is pro jected to be about 1.25 times that of 1973 (876,000 short tons). Projection trends for the U.S. demand are illustrated in Figure 4.2. The forecast for U.S. demand of asbestos by end use is given in Table 4.14. Figure 4.2. U.S. Asbestos Demand, and Projected Trends to 2000 (Clifton, 1975) 48 FMSI 04883 Table 4.12. Time-Price Relationship for Asbestos (Clifton, 1975) Year 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 Average Annual Price, Dollars Per Short Ton Actual Price Constant 1973 Dollars 82.34 84.61 89.78 88.09 90.50 91.17 94.62 95.60 94.85 92.44 98.70 97.92 100.63 101.91 98.93 110.03 115.64 117.54 116.63 122.22 122.27 141.72 143.65 147.42 139.38 139.66 138.35 141.44 141.00 138.26 133.00 140.00 136.38 136.35 133.74 124.75 132.41 132.01 128.32 123.16 122.22 110.90 . 49 FMSI 04884 Table 4.13 Recent Prices of Various Asbestoses (Asbestos Magazine, December, 1975) ARIZONA Per Ton of 2000 Lbs.. F.O.B Globe. Arizona As of April 17, 1975 U S. Dollars No. 1 Crude (Soft) . No. 2 Crude (Soft)................................................... AAA ............................................................................ Group No. 3--Nonferrous Filtering--Plastic Group No. 4--Nonferrous Filtering--Plastic Group No. 7--White Shorfs ...................... $ $2000.00 .1500.00 . 1100.00 715.00-- 800 00 700.00-- 800.00 100.00--200.00 QUEBEC As of December 1, 1975 Per Ton of 2000 Lbs.. F.O.B. Mine Canadian Dollars No. 1 --Crude ........................ . No. 2--Crude.............................................. No. 3--Spinning Fiber No. 4--Asbestos Cement Fiber No. 5--Paper Fiber No. 6--Paper and Shingle Fiber No. 7--Shorts . S . . $3496.00 . .1899 00 891.00-- 1463.00 492.00-- 829.00 278.00-- 392.00 236.00-- 244.00 89.00-- 198.00 CASSIAR Per Ton of 2000 Lbs., F O B. North Vancouver. B.C. As of August 1. 1975 Canadian Dollars Cassiar Mine C-1 .................................................................................. $2916.00 AAA Grade--Nonferrous Spinning Fiber/Canadian Group 3 1685.00 AA Grade--Nonferrous Spinning Fiber/Canadian Group 3 1340 00 A Grade--Nonferrous Spinning Fiber/Canadian Group 3 1020.00 AC Grade--Nonferrous Spinning Fiber/Canadian Group 3 735.00 AK Grade--Asbestos Cement Fiber/Canadian Group 4 524.00 AS Grade--Asbestos Cement Fiber/Canadian Group 4 454 00 AX Grade--Asbestos Cement Fiber/Canadian Group 5 . 416 00 AY Grade--Asbestos Cement Fiber/Canadian Group 5 292 00 AZ Grade--Asbestos Cement Fiber/Canadian Group 6 216.00 Clinton Mine CP Grade--Asbestos Cement Fiber/Canadian Group 4 . CT Grade--Asbestos Cement Fiber/Canadian Group 4 .. CY Grade--Asbestos Cement Fiber/Canadian Group 5 . CZ Grade--Asbestos Cement Fiber/Canadian Group 6 . 492.00 445.00 292.00 216 00 VERMONT Per Ton of 2000 Lbs., F.O.B. Morrisville, Vermont As of January 1, 1976 U.S. Dollars Grade 4T--Fiber .................................................... $ . .--$ 418.00 Grades 5D thru 5R--Fiber ..................................... 275.00-- 324.00 Grade 60--Waste .................................................. . 200.00 Grades 7D thru 7T--Shorts....................................... 83.00-- 160.00 Grade 7TF--Floats (Shorts) ............................ . --- 72.00 Grade 8S--Shorts . . . ; .............. -- 54 00 Hooker No. 1--in 50-lb. woven poly bags/eft 12/1/75 970.00 Hooker No. 2--in 100-lb. woven poly bags/eff 12/1/75 485 00 Table 4.14. Projections and Forecasts for U.S. Asbestos Demand By End Use 1973 and 2000 (Thousand short tons) (Clifton, 1975) End Use Asbestos cement pipe Asbestos cement sheet Flooring products Roofing products Packing and gaskets Friction products Insulation Paper Textiles Other Total 1973 166 64 218 87 26 79 26 18 18 174 876 2000 Contingency Forecasts for United States Forecast Base Forecast Range Low High Probable 475 178 479 190 100 65 104 68 360 233 372 236 150 93 148 94 75 64 75 66 150 110 144 118 30 30 39 34 45 21 40 27 20 19 24 21 400 199 387 260 -- 1,012 1,812 1,114 51 FMSI 04886 5.0 MINING AND MILLING 5.1 U.S. Mines and Mills Although asbestos deposits are located throughout the United States (Figure 5.1), asbestos is mined in only a few states. The map in Figure 5.2 designates the location of mines which are operating or which have been closed recently. In order of decreasing annual production, the mining states are California, Vermont, Arizona, and North Carolina. Table 5.1 lists the American mines which are operating or have recently closed, along with the associated mills. All of the mines produce chrysotile asbestos with the exception of the *' Powhattan mine in North Carolina which produced anthophyllite asbestos. The largest mines are the Vermont Asbestos Group mine (formerly owned by GAF Corp.) in Vermont and the Calaveras Asbestos Ltd. mine (formerly con trolled by H.K. Porter Co.) in Copperopolis, California (Asbestos Magazine, December, 1975). The inactive Coalinga Asbestos Co. mine (Johns-Manville) was the second largest mine in California and the third largest nationally. En vironmental regulations are cited as the prime reasons for the closing of the Johns-Manville mine (Clifton, 1976; Harwood and Blasznak, 1974; Asbestos Magazine, December, 1974, 1975). Although the Powhattan mine In North Carolina was re ported as inactive since 1973 (Harwood and Blasznak, 1974) , a conversation with a Powhattan employee suggests that the mine is currently being operated. Potential mining has been discussed for Alamore, Texas (tremolite asbestos), Sonora, California, and the Yukon region of Alaska (Asbestos Magazine, December, 1972, 1974). It should be noted that actual mining production data for each mine cannot be accurately collected for proprietary reasons. Since California had, 52 FMSI 04887 CO a> a> <i CO 0o1 PU m a) [M 3) [ 53 FMSI 04888 o f Asbestos D e p o sits (Harwood and B la szn a k, 1974) [ L L Figure 5.2. Asbestos Mines in the United States L I I 54 \ FMSI 04889 m 4on 1-1 J 0- aft <D r^ X ON a) H u A *H G P- 4OJ G 4-1 a) iH tH 0o- o 0) ft n <* cd I**** Ov CO iH a> * G H X cd G i--< <N i-H CO cd H CQ 4<y T3 -> GO CO z *o0 om 5 C ON XG> C0 rH EG 1 OV4 0} H rH 5j CH r*** ON pH 0J-0l T<3u a 3 *o a QJ cd g <uc0d CO <3) e a) c; JoC a P cd CGoNO n CO H CO eg U < 35 < 3 CoO o AJ H m OJ a) o 13 oco uC pH m 0) Id H *S-i 3*oo*-uo* t* > oo <M ~4 B 3 ms. 4) J= to U I Is W3a t<os- Om itno Ow w om n<r o o oCL o> U tu HH oa* ca CL ft co. <<_o> o o \o CS M ut o<o oN to M os 1 c o to ot *s 55 FMSl 04890 until recently, several operating mines, the Bureau of Mines has reported annual production for the state. But as a result of recent mine closings, the annual California production report might be terminated (Clifton, 1976). Table 5.1 contains estimates of Harwood and Blasznak (1974) for several indi vidual daily mine productions and the estimate of Asbestos Magazine for annual production of two mines. Based upon the combined data of Harwood and Blasznak, Clifton, and Asbestos Magazine, we estimate that at the present time about 55-65% of the asbestos mined in the U.S. is mined in California, 35-45% comes from Vermont, and less than 5% is mined in Arizona and North Carolina. Until recent mine closings and sales altered the California production, California had accoun ted for nearly 70% of the domestic fiber. The lower limit for economical asbestos production is estimated at 4% asbestos containing ore (Berger and Oesper, 1963). Clifton (1975) evaluated the effect of continuous mine operations on the percent fiber recovery by a linear regression analysis of Quebec mine data (see Figure 5.3). He forecasts that as the age of a mine increases, the percent fiber recovery decreases. This will result in an increasing fiber production cost until mining is no longer prof itable. By reason of analogy, the Quebec data should be generally true for U.S. mines, especially the Vermont mine, which is an outcrop of the Quebec deposits. Based on the above data, the Vermont mine appears close to being mined out. 5.1.1 Ore Characteristics The chrysotile asbestos content of ore varies between deposit locations. The lowest concentration is deposited in the Vermont ore which consists of less than 4% asbestos by weight, and the highest concentration is deposited in the Coalinga, California, district which is approximately 60% by weight asbestos. . 56 FMSI 04891 ' PERCENT 1 Ore and waste rock exclusive of overburden BUREAU OF MINES U.S. DEPARTMENT OF THE INTERIOR Figure 5.3. Quebec Production Trends, From Analysis of 1951 - 1970 Data (Clifton, 1975) 57 FMSI 04892 The Vermont ore deposit is an outcrop of the large Quebec deposits in Canada. While the Vermont deposit contains some spinning grade fibers (Harwood and Blasznak, 1974), most fiber is shorter grade and is consumed in the manufacture of heat resistant products (Asbestos Magazine, December, 1973). The Calaveras Asbestos Ltd. mine in Copperopolis, California, produces the normal long fibered form of chrysotile asbestos which is primarily used in asbestos-cement products (Harwood and Blasznak, 1974; Asbestos Magazine, December, 1975). Three mines, the Coalinga (Johns-Manville), Atlas, and Union Carbide, are in close proximity to each other near Coalinga, California. They work an ore body which is 10 miles long and 0.25 miles wide. The ore from these mines is atypical of asbestos. Instead of a fibrous vein structure, the asbes tos is in a platy, slippery form known locally as desert leather (Harwood and Blasznak, 1974). The fibers from this tract are short and therefore are used in floor tile and reinforced thermoplastics (Asbestos Magazine, December, 1971, 1975). Arizona produces an exceptionally high quality, low iron content asbes tos, most of which is used for electrical insulation and for filtering media (Asbestos Magazine, December 1975). Most of the Jacquay Mine production is exported to Japan (Harwood and Blaszak, 1974). 58 FMSI 04893 6.0 FRICTION MATERIALS Friction materials are used in practically all industries as a key component in clutches for transmitting torque, brakes for slowing down or stopping motion, or as torque limiters. Although friction applications to automobile brakes and clutches are the most important commercially, asbestos-friction applications are not limited to brakes and clutches in automobiles, trucks, busses, construction equipment, and railroad cars. Rather, these applications are found wherever motion must be controlled. The following examples show the diversification of friction material usage: farm tractors, presses, hoists, tensioning devices in production of wire and plastic rope and cable, lift trucks, machine tools, shuttlecars, specialized mining equipment, chainsaws, drilling equipment, spin ning and knitting equipment, x-ray machines, wheel brakes, tape recorders, typewriters, bicycle brakes, snowblowers, and washing machines (Daly et al., 1976). Asbestos is an important ingredient in these friction material products because it imparts strength, good friction properties, can withstand high tem peratures, and is a good insulator. 6.1 Statistics 6.1.1 Use Quantity and Shipment Values From Table 4.9 (p. 46), it can be seen that U.S. demand for asbestos in friction products has ranged from sixty-five to eighty thousand short tons annually from 1964 to 1974. This amounts to approximately 9% of the total U.Si asbestos demand (consumption). The trend in the value of shipments of asbestos friction materials is shown in Table 6.1. During the five year period from 1967 to 1972, shipment 59 FMSI 04894 0 3 0 e a) o a) 43 u MH O 3 0 0) M 3 PQ co 0 H n 40J a o H PMh OCO /-s 44 CO CO U 403 0M 33 O CM 0) 3 0 B cm a. o H 43 CO cn 0 CO CM 0 O 0) O a 0 CM rH 0 ON >H rH VO 0) rH 43 0 H CO VO on CVO4 0 * CM CO Ma II 6 CO 0 <hc-d> gn a <d 3HUH J CH c/3 cd o t-H 13 t! & 0 *0 40) 0 0 OM iH0 -HH P- rH 60-H -t 0 B 0 H 44 *0 O0 H rH <J 0 *rl VO as H CM r*- as rH r-* r** 4* sr -4* io as o CM m VO * CO CO H a\ I 1 CM rH CM o CO Mj* r--l rH rH rH CM rH O r^. vJD CM rH rH as to \D ON 00 CO rH *4* rH 0 44 O H r 0 rH 0 H U o0 0 44 (ft oS 0 0 Pu >N 44 s 00 Vi 0 0> SK O > 01 o0 44 O 00 0 43 rH 0 rH 00 60 60 0 0 a ps 44 4* pu 0 0 0 0> > O 0 01 A O00 44 O rH 00 0 0 *H 43 rH U 0 rH 0 0 0 44 fvt 360 60 P* c o rH 43 rH 0 44 rl 43 *H 0 jj rd 0 o H *H O 0 w rl O 0 rl 44 cd rH rH Td 0 rH rH 44 O <n 44 o U 0 00 u V o O rl t>0 0 0 PH C 0 0 H M 0 O M H iH O M *H M CPm rl CJ O a) a <J O Pm CO a 44 H A Td 0 0 pH m a * Td CO O 0 a) a) >4 0 00 o U 0) a-d CQ X 0 CUTd u CO 0) > 0 rH o > 0 rH CO a> X 0 44 o rO td rs s a 44 O 44 O a> 0 0S 43 CO < H rH Qo <CO 44 a 00 O Td T3 HO O C/3 M O PH CM CM ON CM CO rH in rH rH rH CM CM CM CM CM CM CM ON ON ON CM CM CM CO CO CO rH to o m to o CM CM CM CM CM CM ON ON ON CM CM CM CO CO CO 60 FMSI 04895 values increased by 45%, as compared to a 23% increase for the four-year period from 1963 to 1967. Using an annual figure of 9% for shipment value increases, the total product shipments of asbestos friction materials would be approxi mately $271.3 million in 1975 and $295.7 million in 1976. Table 6.1 also gives a breakdown for the major asbestos friction material products. In 1972, brake linings accounted for nearly 59% of shipment values while clutch facings accounted for slightly over 32% of the shipment values. If disc brake pads are included along with brake linings, then asbestos brake-materials account for 65.6% of the total value of asbestos-friction materials. Clearly then, "brakes" are by f^r the most important commercial product in the friction material category. 6.1.2 Industrial Firms Table 6.2 lists the U.S. manufacturers of asbestos-bearing friction materials along with their respective sales of friction materials in 1975. The larger firms include not only the essentially captive producers, such as the Delco-Moraine and Inland Divisions of General Motors Corporation and the Cycleweld Division of Chrysler Corporation, but also the diversified industrial product manufacturers, such as Raybestos-Manhattan, Bendix, Abex, and H.K. Porter. In addition, the list includes many smaller, typically single-plant firms, which manufacture friction products for both the original equipment and replacement market. . The first eight firms listed on Table 6.2 account for nearly 75 to 85% of the total estimated sales of asbestos friction products in 1975. This ratio is consistent with the historical pattern for the industry, which indi cates that in the 1954 to 1967 period, the eight largest firms accounted for between 86 and 91% of the industry's value of shipments (Margolin and Igwe, 1975; U.S. Bureau of the Census, 1972). 61 i FRASl 04896 Table 6.2. . U.S. Manufacturers of Asbestos-Bearing Friction Materials (Economic Information Systems, Inc., 1976; Margolin and Igwe, 1975; SRC Estimates) Company Raybestos-Manhattan, Inc. Bendix Corporation Abex Corporation General Motors Corp. H.K. Porter Co. Chrysler Corporation Borg Warner Corporation World Bestos Co. National Friction Products Corp. Gatke Corporation Carlisle Corporation Maremont Corporation Plant Location Estimated 1975 Sales of Friction Materials ($ million) Stratford, Conn. Mannheim, Pa. Crawfordsville, Ind. Fullerton, Calif. 110.0 Troy, N.Y. Cleveland, Tenn. 72.5 Cleveland, Ohio Troy, Michigan American Brakeblok Division Winchester, Va. 60.1 Delco-Moraine Div. Dayton, Ohio Inland Division Dayton, Ohio 30.0 Huntington, Indiana Richmond, Ky. 26.0 Cycleweld Division Trenton, Michigan -- Spring Division Bellwood, 111. -- New Castle, Ind. 18.8 Logansport, Ind. Warsaw, Ind. Ridgeway, Pa. Grizzly Products Division Paulding, Ohio 10.2 10.0 9.7 8.7 62 FMSI 04897 Table 6.2. U.S. Manufacturers of Asbestos-Bearing Friction Materials (Cont'd) Company Plant Location Scandura, Inc. Mar Pro Corporation Standco Industries Forcee Mfg. Corporation Royal Ind. Brake Products, Inc. Auto Friction Corp. L.J. Miley Co. Friction Products Co. United States Brake Lining Corp. Brassbestos Mfg. Corp. Southern Friction Material Co. Reddaway Mfg. Co. Molded Ind. Friction Corp. Auto Specialties Mfg. Co. Lasco Brake Products Co. California Blok Co. MGM Brakes, Inc. Wheeling Brake Block Mfg. Co. Charlotte, N.C. Grizzly Brake Division Chicago, 111. Houston, Texas Tappahannock, Va. Danville, Ky. Lawrence, Ma. Chicago, 111. Medina, Oh. Miami, Fla. Patterson, N.J. Charlotte, N.C. Newark, N.J. Prattville, Ala. St. Joseph, Mich. Oakland, Calif. Gardena, Calif. Cloverdale, Calif. Wheeling, W.Va. Bridgeport, Ohio 63 Estimated 1975 Sales of Friction Materials ($ million) -- -- 8.7 -- 5.7 5.7 5.5 4.0 2.9 1.7 -- 1.7 -- -- <1 <1 <1 <1 FMSI 04898 Table 6.2. U.S. Manufacturers of Asbestos-Bearing Friction Materials (Cont'd) Company Plant Location Baldwin-Ehnet Hill, Inc. Trenton, N.J. Thiokol Chemical Corp. Trenton, N.J. P.T. Brake Lining Co. Lawrence, Mass. Hunt/Airheart Products, Inc. Chatsworth, Cal. Re-Bilt Auto Products Corp. Brooklyn, N.Y. Estimated 1975 Sales of Friction Materials ($ million) <1 <1 -- ------- _ --------- 64 FMSI 04899 One important discrepancy in figures should be explained. For 1972, the U.S. Bureau of the Census listed the total value of shipments of as bestos friction products as $209.5 million which was projected as $271.3 million for 1975 in Section 6.1.1. From Table 6.2, the estimated sales of asbestos friction materials in 1975 total nearly $370 million for the listed figures; the companies with no listed figures may total another $50 million. The difference from the value of shipments as reported by the Bureau of the Census and the estimates given in Table 6.2 are due to variations in definition and reporting coverage. Shipment value does not include freight charges and excise taxes which are included in the actual sale cost. Also, the Bureau of the Census figures are based upon surveys at 23 asbestos-friction material establishments. Table 6.2 contains 44 establishments. Although the Bureau of the Census survey probably includes most of the larger establishments, the ones which were not surveyed are not available. 6.1.3 Plants ' Figure 6.1 shows the geographical dispersion of friction materials plants in the U.S. Not surprisingly, they tend to be concentrated in and around the major metropolitan centers of the Northeast and Midwest, with a few plants located in California to primarily cater to the needs of the automobile assembly plants in that part of the country. As would be expected of a mature industry, most of the plants and equipments are old, usually over forty years of age, with the possible exception of newer captive facilities belonging to the automobile manufacturers. Pro duction processes have changed only marginally over the years, and labor rather than capital intensity appears to be the norm in most of the older plants (Margolin and Igwe, 1975). 65 FMSl 04900 L- L 66 FMSI 04901 O ak. } Mmn F ig u re 6 .1 G e o g ra p h ica l D iapereion o U.S. F ric tio n M a te ria ls P la n ts (M o d ifie d from M a rg o lin and Igw e, 1975) 6.1.4 Future Projections for Asbestos Use (Clifton, 1975) Asbestos demand for friction products was projected to the year 2000 at an annual growth rate of 1.50 percent. This figure was based on a formula derived from least-squares regression analysis of total asbestos demand modified by the estimated growth in the automobile industry and economic indi cators, which showed the best correlation. Asbestos is an important part of many types of friction materials for use in automobiles, trucks, and other transportation equipment. Modem industry could scarcely function without asbestos friction materials. In addi tion to using asbestos in brake linings, today's motor cars, equipped-with automatic transmissions, get their drive from metal transmission disks, which are covered with a super-tough paper containing crocidolite asbestos. The average automobile with power shift contains from 8 to 12 of the paper lined disks. Although the quantity of asbestos in each transmission is small, the output of more than 8 million automatic transmissions annually requires disk paper production in hundreds of tons. A new composition disk-brake-shoe unit containing asbestos, designed to meet the critical braking requirements for the new 150-mile-per-hour passenger train systems, has been developed. Based on an estimated forecast of the number of motor vehicles produced in the year 2000 (approximately double 1973 production) and on the assumption that the use of asbestos per vehicle will remain at present levels, the forecast for asbestos demand in user-operated vehicles is projected to 118,000 tons. An increased number of public transportation vehicles and equip ment using parts made of asbestos or maintaining the present quantity used per vehicle could result in a demand as high as 144,000 tons. 67 FMSI 04902 [ II J 6.2 Manufacturing Process Technology I Several different processes are used to manufacture asbestos brake linings and clutch facings. Manufacture can be accomplished by a molding proc >1 ess, in a dry or wet-mixed state, or by a woven process; these processes, which are described below, are taken from Gregg (1974). The raw materials used for 1 forming asbestos-friction materials are discussed in Section 6.3. jl 6.2.1 Molded Products 6.2.1.1 Dry-Mix Process 'l The manufacturing steps typically used in dry-mix molded brake lining manufacture are shown in Figure 6.2. The bonding agents, metallic 1 constituents, asbestos fibers, and additives are weighed and mixed in a two- stage mixer. The mix is then hand-tamped into a metal mold. The mold is placed i in a preforming press which partially cures the molded asbestos sheet. The [ asbestos sheet is taken from the preforming press and put in a steam preheating mold to soften the resin in the molded sheet. The molded sheet is formed to the proper arc by a steam-heated arc former, which resets the resin. The arc-formed I sheets are then cut to the proper size. The lining is then baked in compression molds to retain the arc shape and convert the resin to a thermoset or permanent I condition. The lining is then finished and, after inspection, is packaged. The finishing steps include sanding and grinding of both sides to correct the thick 1 ness, edge grinding, and drilling of holes for rivets. Following drilling, the lining is vacuum-cleaned, inspected, branded, and packaged (Gregg, 1974). \ 6.2.1.2 Wet-Mix Process I Figure 6.3 shows the major steps in the manufacture of wetmixed molded brake linings. The name "wet mix" process is a misnomer and refers l 68 FMSI 04903 CONSUMER Figure 6.2. Dry-Mixed Brake Lining Manufacturing Operations (Gregg, 1974) 69 FMSl 04904 to the use of a solvent. The ingredients of the molded lining are actually relatively dry. After weighing, they are mixed in a sigma blade mixer. The mixed ingredients are then sent to grinding screens where the particle size of the mixture is corrected. The mixture is conveyed to a hopper and is forced from the hopper into the nip of two form rollers which compress the mixture into a continuous strip of friction material. The strip is cut into the proper lengths and then arc-formed on a round press bar. The cutting and arc forming operations are done by separate units. The linings are then placed in racks and either air-dried or oven-dried to remove the solvent. An alternative process is to place the arc-formed linings in metal molds for baking in an oven. From the ovens, the linings are finished, inspected, and packaged (Gregg, 1974). Molded clutch facings are produced in a manner similar to the wet-mixed process. The rubber friction compound, solvent, and asbestos fibers are introduced into a mixer churn. After the churn mixes the ingredi ents, the mixture is conveyed to a sheeter mill which forms a sheet or slab of the materials. The sheet is then diced into small pieces by a rotary cutter. The pieces are placed in an extrusion machine which forms sheets of the diced material. The sheets are cut into the proper size and then punch-pressed into doughnut-shaped sheets. The scraps from the punch press are returned to the extrusion machine; The punched sheets are placed on racks and sent to a drying oven and then a baking oven for final curing and solvent evaporation. The ovendried sheets are finally, sent to the finishing operations. Figure 6.4 illu strates the steps in the manufacture of molded clutch facings (Gregg, 1974). 6.2.2 Woven Products Woven clutch facings and brake linings are manufactured of high strength asbestos fabric that is frequently reinforced with wire. The fabric is 70 FMSI 04905 RAW MATERIALS STORAGE PROPORTIONS SOLVENT sa 6s ad SOLVENT FINISHING L INSPECTION PACKAGING STORAGE CONSUMER DUST Figure 6.3. Wet-Mixed Molded Brake Lining Manufacturing Operations (Gregg, 1974) 71 FMSI 04906 CONSUMER Figure 6.4. Molded Clutch Facings Manufacturing Operations (Gregg, 1974) 72 FMSI 04907 predried in an oven or by an autoclave to prepare it to be impregnated with resin. The fabric can be impregnated with resin by several techniques: 1) immer sion in a bath of resin, 2) introducing the binder in an autoclave under pressure, 3) introducing dry impregnating material into carded fiber before producing yam, and 4) imparting binder into the fabric from the surface of a roll. After the solvents are evaporated from the fabric, it is made into brake linings or clutch facings. Brake linings are made by calendering or hot pressing the fabric in molds. The linings are then cut, rough ground, placed in molds, and placed in a baking oven- for final curing. Following curing, the linihg is finished, inspected, and packaged (Gregg, 1974). Figure 6.5 illustrates the manufacture of woven clutch facings. The treated fabric is cut into tape-width strips by a slitting machine. The strips are wound around a mandrel to form a roll of the fabric. The roll is pressed in a steam-heated press and then baked in an oven to cure the resin in the clutch facing. Following curing, the clutch facing is finished, inspected, and packaged (Gregg, 1974). 6.3 Composition of Friction Materials Many raw materials, including some whose exact roles are regarded as proprietary knowledge, are used in varying quantities in the manufacture of friction materials. The major, or foundation constituent, of practically all organic friction materials is asbestos fiber. The asbestos usually used in friction materials is chrysotile from Quebec or Vermont (Jacko and DuCharme, 1973); grades 3-7 are used; however, grades 5 and 7 account for nearly 83% of the total (Clifton, 1975). Asbestos is used because of its thermal stability, relatively high friction level, and reinforcing properties. 73 FMSI 04908 TREATED FABRIC | |SL.T TING ] PREF ORM WIN!DING COOLING WATER STEAM 3^ =SS ]| BAKING OVEN | FINIS HING | INSPECTION PACKAGING ISTORAGE CONSUMER COOLING WATER CONDENSATE DUST Figure 6.5. Woven Clutch Facings Manufacturing Operations (Gregg, 1974) 74 FMS1 04909 Asbestos alone does not offer all of the desired friction properties. Therefore, other materials, known as property modifiers, are added to the asbes tos fibers. Modifiers are varied in type and content to provide desired levels of effectiveness, wear, fade, recovery, and noise. A binder is also added to hold the other materials together with adequate strength. 6.3.1 Binders V Table 6.3 lists binders and property modifiers which are used in automotive brake linings. The binders used in the automotive industry today are primarily phenolic-type resins which are noted for high binding efficiency and ability to withstand pyrolytic breakdown (Rohl et al., 1976). They are prepared as the condensation product between the appropriate phenol (sometimes modified) and formaldehyde in the presence of an acidic catalyst to yield the novolak. When mixed with an appropriate curing agent, they polymerize at elevated tem peratures to an insoluble, infusible mass (Jacko and DuCharme, 1973). Other resin systems in wide use are based on elastomers, drying oils, or combinations. 6-. 3.2 Property Modifiers Perhaps the widest range of materials used in friction products are the property modifiers. Table 6.3 indicates the range and diversity of these modifiers. In general, property modifiers can be divided into two classes non-abrasive modifiers and abrasive modifiers (Jacko and DuCharme, 1973). 6.3.2.1 Non-Abrasive Modifiers Non-abrasive friction modifiers can be classified further as low friction and high friction. The most common and best known of the high friction materials is known as friction dust. This is a cured resinous materi al. The most frequently used variety is derived from cured or polymerized 75 FMSI 04910 Table 6.3. Binders and Property Modifiers In Automotive Brake Linings (Rohl et al., 1976; Jacko and DuCharme, 1973; various patent literature; Bark et al., 1975) Binders Phenolic-type resins Natural rubber Buna N rubber Nitrile rubber Tire scrap Pitch Cork Gilsonite Elastomers Drying oils Property Modifiers Graphite Coke Coal Carbon black Gilsonite Use Function Lower friction coefficient and noise 11 VI tv II Rottenstone (SiO,,) Quartz (SiO,) Wollastonite (CaSiO^) Brass Chips Zinc and compounds Alluminum Remove decomposition deposits It 11 II It 11 Limestone (CaC0_) Clays Silicas Barite Improve wear resistance II It II Lead and compounds Lubricant to prevent grabbing Friction dusts See discussion in Section 6.3.2.1 Antimony compounds Calcium compounds Copper and compounds Barium hydroxide Potassium dichromate Magnesium carbonate Iron oxide Cryolite (Na^AlF^) Fluorspar Cardolite Nickel Naptha Sulfur Methylethyl ketone Not available IV II 11 11 It II VI II 11 II II 11 11 Molybdenum disulfide Calcium fluoride Lubricant Lubricant 76 FMSI 04911 cashew-nut-shell liquid, chemically a phenolic compound. When heated with hardening agents, such as hexamethylenetetramine or formaldehyde, it becomes sufficiently hard or polymerized to be granulated. Many other cured resinous or polymeric materials, some with fillers, are also used. Certain friction dusts are combinations of these materials and cashew resin. Ground rubber is normally used in particle sizes similar to, or slightly coarser than, those of the cashew friction dusts for noise, wear, and abrasion control (Jacko and DuCharme, 1973). Carbon black, graphite, petroleum coke flour, or other carbonaceous materials may also be added as friction modifiers to lower the friction coefficient or to reduce noise. These materials are normally used in the form of fine powders or particles, although graphite is sometimes used in coarse particles or pellets. The amount of friction modifier added is dependent upon the properties desired in the final composite (Jacko and DuCharme, 1973). 6.3.2.2 Abrasive Modifiers Abrasive modifiers, such as alumina and the silicas, are usually used in relatively small amounts and only in very fine particle sizes (generally 100 mesh or finer). Particle size is limited by the fact that large particles of such hard materials would groove and wear the mating surfaces. Minerals are generally added to improve wear resistance at minimum cost. Those most commonly used are ground limestone (whiting) and barytes (barium sulphate), though various types of clay, finely divided silicas, and other inexpensive or abundant inorganic powders may also perform this function. Such materials are inorganic in nature and tend to detract from noise properties and mating surface compatibility (Jacko and DuCharme, 1973). Metals or metal oxides may also be added to perform specific functions. Brass chips are frequently found in heavy-duty friction materials 77 FMSI 04912 where, as scavengers, they break up undesirable surface films. Zinc and alumi num are also used. Zinc chips, in relatively small amounts, can contribute significantly to recovery of normal performance following fade (Jacko and DuCharme, 1973). 6.3.3 Composition The average composition of a typical automobile and truck brake lining is shown in Table 6.4a. Individual mixes may vary considerably from these averages. Table 6.4a. Average Brake Lining Composition (Lunch, 1968) Ingredient Asbestos Resins and Polymers Oxides and Pigments Metals Carbon, Graphite, etc. Automobile 55 28 9 3 5 100% Truck 33 48 16 2 1 100% Manufacturers are very reluctant to release their exact composi tions due to proprietary considerations. A search of patent literature reveals limited information, although several examples from the patent literature are given in Table 6.4b. 6.3.4 Summary The tables and examples given in Section 6.3 have been included to illustrate the wide variety of compositions which are possible for fabrica tion of automotive and truck brake linings. Brake linings have been singled out 78 FMSI 04913 Table 6.4b. Brake Lining Compositions from Patent Literature Example No. 1* Asbestos Barite Phenolic resin binder Brass Magnesium carbonate Limestone Organic calcium powder 55 10 20 5 8 8 10 Example No, 2** . Asbestos Phenolic resin Nitrile rubber Cashew dusts Calcium fluoride Copper iodide 60 15 3 v 12 7 3 Example No. 3******* Asbestos Barite Graphite Brass Phenolic resin Lead oxide Buna N rubber Naphtha Copper sulfide Methyl ethyl ketone 35 2.5 7 13 7 11.5 8 7 12.5 4 Example No. 4**** Asbestos Tarry residue Barite Phenolic resin Graphite * Sakata jet al., 1974 (Hitachi) ** Toyota Central Research and Development *** Keller, 1969 (Abex) **** Mitchell, 1974 (duPont) Labs, 1971 50 12 20 20 2 79 FMSI 04914 from the asbestos-friction products for examination because of their dominance of the asbestos-friction products market as shown in Table 6.1. When the varia tions of compositions are coupled with the variations of manufacturing process methods (as described in Section 6.2), it is possible to view a brake lining made by company A as substantially different from a brake lining made by com pany B, although the intended use applications may be the same. From this standpoint, it is entirely reasonable to speculate that asbestos emissions during automotive brake use may vary in concentration, depending upon composi tion and process manufacture of the individual linings. 6.4 Asbestos Emissions from Brake Lining Use Asbestos has been identified in over 200 air samples taken from the atmosphere of 49 cities in the United States (Nicholson et^ al., 1973); asbestos was present in every sample taken. Asbestos has also been found in air samples from European cities (Holt and Young, 1973) and from air samples collected in Australia (Alste et^ al., 1976). The asbestos manufacturing industry may not be the source of the asbestos emissions found in urban air samples cited above. According to Holt and Young (1973), "the object of our investigations was only to determine whether asbestos fibres are present in the atmosphere of towns where there is no asbestos industry. The result was positive in every case." The source of asbestos emissions, in the absence of asbestos mining and industry, is a matter of speculation. Holt and Young (1973) and Selikoff et al. (1972) suggest that the asbestos source may be construction which uses building materials made from asbestos. Alste et^ al. (1976) consider, as a source, that asbestos emitted from automobile brake linings is a "strong possibility." Alste et^ al. (1976) found that the air concentration of asbestos 80 FMSl 04915 f I was much higher at points where considerable braking occurred, as compared to I points of virtually no braking. This result is apparently in agreement with measurements made in New York City which found that the asbestos air concen [ trations contiguous to a toll booth were three to five times higher than back I ground levels (Anderson et al., 1973; Nicholson et al., 1971). This subsection V will consider the possibility of asbestos emissions from brake lining use. [ 6.4.1 Published Literature A number of articles and publications (Alste et al., 1976; s Rohl et al., 1976; Jacko and DuCharme, 1973; Jacko et al., 1973; Bush et al., I 1972; Hatch, 1970; Hickish and Knight, 1970; Lynch, 1968) have discussed the asbestos emissions from the use of brake linings. Table 6.5 gives a brief I summary of this published data in terms of methodologies and results. As can be seen from Table 6.5, there are important discrepancies in the results obtained. l 6.4.1.1 Discrepancies in Asbestos Content of Emissions or Debris Lynch (1968), Hatch (1970), Hickish and Knight (1970), and i Jacko and DuCharme (1973) reported figures in the range of 1% or less for the l asbestos content of emissions or debris resulting from brake lining use. Bush et al^. (1972) and Rohl et al. (1976) arrived at figures which are substan tially higher, 44% and 2-15% asbestos content, respectively. While Alste et al. (1976) did not arrive at a percent figure, they did conclude that the major 1 effect of braking appears to be separation of bunches of fibres and reduction of 1 their average length, but not alteration of their crystal structure. This conclusion may certainly result in a relatively high asbestos content for wear i debris. i 81 i FMSI 04916 [ I I 0) S l to a uU uqu U 4) 9 BO >^4 Uy c 01 O rH BC 01 JO * nr oo U U rJ 01 - e u a-4 *0 o u -4 o oj to co 41u aq> a -*4- > o > OCXS V Ia s M CP lB O Vi 4-4 e - a jnoua wcaIui ou0so1o m 0mo>eto H O b 04 Cl SI C O 7 >U rl O H 00 rG O v< CO CO S c u o *- H e -h e. 6 3 CfloO 6 W 50 ** cn 0.Oc u o 6u CO *j a u *h i uo Cl BO Ur Vi o o J3 "s &CO o ip J> EO eo t4 oiau c n b- U . C O e rH 4LiMtMOH 01 C 0U1 Ape )00 b c o lle c te d on acnbrane f i l t e r s i <d P "IU 0) 73 s u 1 a t 01 i rH 2 CO iib-ri b> 'tS Sii-irl 1 U (1 I 0 > . H IU BO C W 'r* *4 1 o o. cm m t (J Cl BO 0) N u 3 3 u *3 j< > *hu CJ e tj W rt rH C| P H to o. ec Li W u u 0 Q *9 i H35s5i*-i <0 to tc41 Li 6 N 60 CJ aa > b C U B O li 60 O s -a 01 C LI O C Cl -4 o 01 1 <0 -o *0 ! U 61 Vi I SO B0 O -Hr , -i . U CO y to a 0 C b-flH COO -H fl <0 "H IS." 1 t4 to 9J CJ 60 3 I CL 6 T3 O -Q CJ -H "H -a h H Cl O a Li o i 2 > 1 O s =*3 B 'Q V H H O iJ Tl b 1 a ci i se -H 3 O 6 >. ^ Cl b V > i ir> vO 0W uK *C4 O b0 oo 11 q wo ua 1e v v WH P O-4 a O "rl U -r4 C Jh iJ U dB 641 H*H 4Q1u H*H (QUUnObb Li Cl &. Cl O CO 6 CL <t <4 (Q j QU1 O, CJ 60 rH VriH 1 c n c *4 e 1 > 01 "rl t cn *an Eo rH b <4 V b C j ^ (0 *0 <Li ** a) r-f i s H a i X 815JQ tA >r4 O r- U Q O C! JO fL. CJ Ot to to o --1 i L 82 FMSI 04917 to tco S-I js -u 2g Q) o Uc*sK ^4 ^W-xdi xJMeM tl ou tooth 4 Sa <*m CaBU OUto .O Oc W6oi .u-t>uoi, u 8G C B C >V *J qj i -H B O U 00(O9 av3 tl 10 h0 h9 C tic MB u O e v x p. <.*-r4te0j;hh4i *th>*4 u3 O B *4 > o, > C *"i <9 S -a (I w II b 3 >. *H 0 <H *h o g W3C>0.CO 0**0 .O "O C OO ONUB Jtj004(0fiuit 0> CO CD 00 IIG -I3W JJ33 Ha JOS * Bo- v4bBh3-*>* Mt363gHf C*tV6.WtUHsot gontMVfr<he* C O C V = S o a s <oa-t too co. oc bouu C ho - >as I- *u- C ho >aH 3> c CJ iJ c I *9Q Oin t*i4 nO bO Ii C O B * ; o ** C-- birt 0-0 OU (MS *c H t^o O to O of <tM* o 8 in \o l Q) H CO H Sg to >> tn 00 to 0aS WWc 83 FMS1 04918 The 44% figure computed by Bush et. al. (1972) is based upon a neutron activation analysis, which is a technique for finding the elemental composition of a sample by irradiating the sample with neutrons, thereby causing the elements to become radioactive. Bush et al. is careful to point out that chrysotile asbestos is a magnesium silicate and neither magnesium or silicon are able to be determined utilizing the particular technique. Therefore, asbestos content of the wear debris was determined by means of a scandium concentration. Scandium was a trace element (y 4 ppm) present in the chrysotile used in the experiment. Neutron activation can be a very precise and useful technique for determining elemental composition; unfortunately, the asbestos content of any particular wear debris sample cannot be computed by an elemental analysis. Chrysotile asbestos is a unique crystal structure of a magnesium silicate (see Section 2.1); heat or other physical means can destroy this unique structure, thereby creating a different compound with different properties. However, the elemental composition of the different compound will be identical with chryso tile. Both Rohl et al. (1976) and Jacko and DuCharme (1973) determined that the magnesium:silicon ratio of an asbestos friction material is the same before use and after use (as determined from wear debris via chemical analyses). There fore, the 44% asbestos content figure computed by Bush et al. (1972) does not represent the asbestos content, but rather it represents the magnesium silicate content. When considering wear debris from friction materials, neither neutron activation nor chemical analyses are useable techniques fpr analysis of asbestos concentration. The major conflict to be resolved is the high asbestos content suggested by Alste (1976) coupled with the 2-15% asbestos content figure 84 FMSI 04919 obtained by Rohl et^ al. (1976) versus the 1% and less figures obtained by the remaining publication sources listed in Table 6.5. The difference of results appears to be based upon collection methodologies, analysis techniques, and interpretations. 6.4.1.2 Collection Methodologies and Particle Size Distribution The first major consideration of methodology is the type of samples which were collected; that is, samples produced by laboratory simula tions versus samples produced during actual, real-life use. Jacko and DuCharme (1973) and Lynch (1968) collected laboratory samples produced by simulations while Alste eit al. (1976), Rohl et al. (1976), Hatch (1970), and Hickish and Knight (1970) collected real-life samples. There may be an open debate as to which collection method produces the best final results. Laboratory simula tions, as conducted by Jacko and DuCharme (1973), allow entire brake assemblies to be enclosed, and therefore, all conditions could be monitored or controlled and all emissions can be collected. On the other hand, samples collected from real-life use are not only relevant, but they may provide the truest indication as to the asbestos emitted from brake lining use. Conditions encountered during actual use may not be totally reproducible in the laboratory; hence, the asbes tos emission factors may be significantly different. Another area of consideration is the asbestos particle size distribution in the wear debris. Rohl et al. (1976) determined that approxi mately four-fifths of the wear debris fibers are shorter than 0.4 pm in length while Jacko and DuCharme (1973) found that 30% of the fibers were from 0.25-0.50 pm in length. According to Rohl et al., some of the discrepancies between their data and those of Jacko and DuCharme may be attributed to Jacko and DuCharme's 85 FMSI 04920 use of lower magnification (22,000X vs. 42,000X), at which fibers shorter than 0.20 pm may not be easily seen or identified on the electron microscopic screen. Hatch (1970) also produced size distribution figures, finding that 94% of the fibers fell in a 2-5 pm length range; however, there is no indication that Hatch attempted to look for fibers shorter than 2 pm. Alste et al. (1976) found that the majority of particles, which consisted of small bundles of fibers, had a maximum dimension of <_ 2 pm. The best available data (Rohl et al., 1976; Jacko and DuCharme, 1973; Alste et al., 1976) indicates that a very high percentage of the asbestos present in brake lining wear debris is shorter in length than 2 pm, with a substantial portion shorter than 0.5 pm. 6.4.1.3 Analysis Techniques Hickish and Knight (1970) fail to discuss analysis techniques used to determine the asbestos content in their wear debris and, also, do not fully describe collection methods. Under these circumstances, it is difficult to accept their results at face values. Hatch (1970) is deficient in analysis methodology also, although it appears that he used electron microscopy in sizing particles down to 2 pm. Since the Rohl et al. (1976), Jacko and DuCharme (1973), and Alste et al. (1976) studies are the best studies yet conducted on brake lining asbestos emissions, a closer examination of the three is warranted. As seen from Table 6.5, Rohl et al. determined their 2-15% asbestos content from X-ray diffractometry (both continuous and step-scan modes were used). According to Jacko and DuCharme, "asbestos is readily identified /When alone or in simple mixtures at high concentrations by the following ana lytical methods: X-ray diffraction, thermal methods, microscopy, and infrared 86 FMSI 04921 analysis. However, in complex mixtures, or at very low concentrations, the analysis for asbestos is very difficult. In brake wear debris, the problem is compounded because the reaction products of asbestos, fosterite and olivine, have similar elemental ratios and similar X-ray diffraction patterns. The only sensitive method which can be used is microscopy." This conclusion by Jacko and DuCharme is apparently based upon, the assumption that samples that they were going to produce would contain 1% or less asbestos; an accompanying table esti mated the asbestos content of wear debris to be less < 1%. Apparently they did not use X-ray diffraction because they assumed the asbestos concentration would be too low. In the percent range reported by Rohl et^ al., namely 2-15%, X-ray diffraction is very likely an appropriate technique for quantitative chrysotile determination. Two published reports (Goodhead and Martindale, 1969; Crable, 1966) of X-ray diffraction techniques for determination of asbestos in dusts support the contention that chrysotile can be quantified with good accuracy in the percent ranges reported by Rohl et al. Rohl et: al. further verified chrysotile presence by transmission electron microscopy and selected area electron diffraction. "Chrysotile was found, both in fiber and fibril form, with unaltered structure and chemical composition. Its frequency of occurrence was consistent with, but lower than, the quantitative determination made by X-ray diffraction analysis. However, it should be noted that X-ray diffraction analysis is based on both free fibers and fibers present in clumps; the latter would obscure the presence of discreet fibers on electron microscopy study." Alste e_t al. (1976) determined the presence of chrysotile asbestos by electron microscopy and electron diffraction and concluded that the 87 FMSI 04922 major effect of braking appears to be in separating bunches of fibers and reducing their average length but not in altering their crystal structure. This is an important result in terms of the following consideration: If only 15%, or -downwards to less than 1%, of wear debris is asbestos, what happens to the major portions of the asbestos originally present in the brake lining? Lynch (1968), Hatch (1970), and Hickish and Knight (1970) present a prevalent theory that "hot ^spots'' created during braking cause the local asbestos fibers to undergo thermal degradation which results in thermal metamorphosis of the asbestos Into a dif ferent mineral, such as fosterite(olivine). Jacko and DuCharme (1973) assumed that 20-40% of the wear debris composition would be olivine. However, according to Alste et al. (1976) concerning wear debris from brake linings, "there was no indication from the diffraction pattern of the presence of fosterite;" this result was in agreement with Rohl eit al. (1976) who also could not verify the presence of fosterite. Rohl et al. (1976) and Jacko and DuCharme (1973) dis cussed other forms of brake lining wear, in addition to thermal wear, such as abrasive wear and macroshear wear. However, the end result is probably this: the asbestos present in the original brake lining, excluding the asbestos which is emitted in the wear debris, is converted by thermal or other physical proc esses into magnesium silicates or other recrystallized magnesium silicate structures different from asbestos. In addition to unaltered chrysotile fiber in the wear debris, Rohl et al. (1976) observed partially altered and completely recrystallized fibers. Holt and Young (1973) reported that some of the asbestos fibrils collected in European city air appeared to have been heated. 6.4.1.4 Other Considerations The Rohl er _al. (1976) study is based upon a wider and more random sampling than that of Jacko and DuCharme (1973). Rohl et al. selected 88 FMSI 04923 wear debris samples from ten random automobiles undergoing brake maintenance while Jacko and DuCharme's wear debris samples came only from original auto equipment, a partial relining, and a relining for the car tested on the dyna mometer. Alste ej: al. (1976) also collected random samples of wear debris from an auto repair shop, but apparently from only a few cars at most (a much smaller sampling than Rohl at a_l.). Neither Rohl et al. (1976), Jacko and DuCharme (1973), nor Alste jit al. (1976) considered, or tested, brake linings manufactured by dif ferent companies, different technical processes, or different compositions in any systematic manner which would be representative of the entire brake lining industry. Hence, there has been no experimental study conducted which can con firm or refute the supposition that brake linings made by different companies, processes, and compositions may contribute varying amounts of asbestos emissions into the environment. 6.4.2 Emission Quantities Table 6.6 gives the estimated annual asbestos emissions for vehicles as computed by Jacko and Du Charme (1973). These figures are based, in part, upon Jacko and DuCharme's figure of less than 1% ('''0.2%) asbestos content of emission debris. They also made the following estimations: ' (1) The total amount of asbestos contained in all of the automotive brake friction materials sold each year is about 103 million pounds which corresponds to ''-118 million pounds prior to grinding and drilling. (2) The total amount of asbestos contained in all automotive clutch friction materials sold each year is about 4.5 million pounds. 89 FMSl 04924 f to 8 rl o o O o o Uo o PO o 0 V n* +. a>* mft oft m ft u 00 CM rH CO rH a) c4 Or^ CM - vO* H rH rH 0 ou d O f co r~. O' H tu O Ee o 0 o J3 oo ro CM A a> CM O mT O m or-- cn O vO CM O CO ft in I <D H rl U< 3 i ca So rQH 4J n3 CO 'H \ X) O U 3 O 1 Ooo CM CO ft <3* COft oo CM CO oft CO o r*-. vO <r in 00 AoUS Pi o o> 00 <r CM rH 00 CM rH M n CO rH t t-oJ 5*. Si a CO 3 <rs i HC 0FOH3J to teHo n < a ooo ooo oft oft oft ooo MoJft o rHft o v0 ft vO CM OV rH oO oO oft oft om o CM rH VO ft rH vD S CtOo c H *H rH U cCaO cd l rH u ^0 (0 a ft u ucd VO i r3H cd H l n CO CO CO cu o cd CO CO 3 o H aM O a 3 co Mu O rH ft 0) u cd c>d Ci Uou CO rH B H PC 2 CO rH cud O H 4H 3 a> CJ /3 3 rH o 3 M 1 90 I FMSI 04925 (3) The combined total of brake and clutch friction material worn away annually is 123.6 million pounds (117 (brakes) + 66 (clutches) = 123.6). Assuming an average asbestos content of 60%, the amount of asbestos worn away as friction material wear debris is 'W4 million pounds. Based upon available data from other sources (Clifton, 1975; U.S. Bureau of the Census, 1972, 1975), the estimations made above are quite reasonable and are probably good figures to use in emission computations. Table 6.7 lists the estimated asbestos emissions using the Rohl et. al. (1976) figure for the asbestos content of wear debris. Computations were made using the same assumptions and method as Jacko and DuCharme (1973); the only variation is the use of different asbestos content percentages. Rohl et_ al. (1976) arrived at an average asbestos content figure of 3-6% (there fore, a median of 4.5% is listed in Table 6.7) and high-low values of 2-15%. A comparison of Table 6.6 and 6,7 reveals that the total annual asbestos emissions reported in Table 6.7 (4.4% median) is nearly 22 times higher than the total reported in Table 6.6. The focal point of the difference is the percentage of asbestos which survives in the wear debris. Jacko and DuCharme (1973) determined that approximately 3% of the asbestos emission become airborne. Based upon sample concentrations collected at freeway exits, Alste et al. (1976) concluded that only a small fraction of the total dust formed becomes airborne, which is consistent with Jacko and DuCharme. 6.4.3 Human Exposure to Asbestos Emissions During Brake Lining Maintenance and Repair In the United States, an estimated work force of at least 900,000 auto mechanics and garage workers is potentially exposed to asbestos in 91 FMSI 04926 40o-) 0CO) *0 <0 M O CS o O o oooo H 4J oA o tV o tv a rH o o to ua> 0) r- 00 00 4J rH CM CO <S> A 5o Pi rH rH rH cd vO 4J o o->H H a) O o o aoo o oCM M o o o O tv tv tv tfi as o o ao H VO rH CO rH rl <t* 4J rO rl [ o 4-> Pi CO n-t 00 C o o O 4J o O o S o o o CO [ 3 o tv * tv 1 ooo a)CO oa o CO o CO CO CF\ u tv t< * [ 'SrH O --t CT CM I> g. M CO 0 i gco oH CO CO rl WB -CMHO 4-1 CO H (!) w o o O o O O rH rO ooO cd 0 CO o o o4-J oO 4 oc CM tv n CM H iH rl m <3" cd CO tv tv tv I CO CD Z> CO rH rH CO *H rH i 4o-1 o m 3 W caoi um i ,e co 3 /"V cd a) 00 > oo a cd o rl aj u wC iH td 6 Wco Oo CO j-i D cd *>_ > ^ cd vo 4j a> l l CO CM m LO H CO 0) rH O vO -a 3 *M o 4" I s H L 92 [ FMSI 04927 the servicing of both brake and clutch linings (Rohl et al., 1976). Measurable concentrations of asbestos fiber have been observed and reported in the work environment of workmen involved with brake and clutch linings maintenance and repair (Hickish and Knight, 1970; Hatch, 1970; Boillat and Lob, 1973; Rohl et al., 1976). When a vehicle is brought into a repair shop for brake lining inspection or replacement, the wheel is removed and the loose dust is removed from the drums and back plates, generally by means of a compressed air jet. A cloud of dust is produced by this air jet which is visible for several minutes. Table 6.8 lists the fiber concentrations which were measured as a result of the dust cloud by the most relevant study (Rohl et al., 1976) to American standards of exposure; also given are concentrations measured for common truck servicing operations. The result of the Rohl et al. (1976) study indicates that it is common for OSHA asbestos-fiber concentration standards to be exceeded during brake cleaning operations. It should be noted that fiber counts made during this study were in accordance with procedures adopted by OSHA. Essentially, the analysis consists of counting fibers 5 to 100 pm using phase contrast microscopy at a magnification of 400X. Section 6.4.1.2 revealed that most of asbestos present in wear debris is much smaller than 5 pm. Rohl et^ al. (1976) estimated that 80% of the fibers present are shorter than 0.4 pm. Accepting these results, it is obvious that the asbestos exposure during brake servicing may be a great deal higher than is indicated by OSHA test standards. 93 FMSI 04928 Table 6.8. Asbestos Concentration During Automobile and Truck Brake Service* (Rohl et al., 1976) Operation Distance (ft) Number of Samples Fiber Concentration (fibers/ml) Mean Range Auto - Blowing dust out of brake drums with compressed air 3-5 5-10 10-20 4 16.0 6.6-29.8 3 3.3 2.0-4.2 2 2.6 0.4-4.8 i Truck - Renewing used linings by grinding 3-5 10 3.8 1.7-7.0 ** Truck - Beveling new linings 3-5 5 37.3 23.7-72.0 [ * Fibers 5-100 ym in length, counted by optical microscopy. [ I 6.5 Alternatives to Asbestos as a Friction Material 6.5.1 The Role of Asbestos in Friction Linings Originally, automotive brake linings were made from a cotton i textile material which was impregnated with drying oils and cured to form a strip of material which was flexible, conformable, and mechanically very strong. The main purpose of the drying oil was to protect the cotton from attack by atmospheric oxygen, which, even at the temperatures reached by early brakes, would have resulted in burned cotton had its surface been exposed to the air. 1 As brake operating temperatures increased, it was found that cotton started l to degrade and lose its strength even though still protected from oxygen attack. In other works, the cotton suffered thermal degradation instead of I oxidative degradation (Hatch, 1970). l 94 1 FMSI 04929 Around 1910, a technological breakthrough was achieved when it was discovered that asbestos could be woven and used to replace cotton because asbestos neither burns nor loses its strength below about 500C. When braking operations became more severe, in the 1940*s, brake linings began to be manu factured by moulding powdered resins with short asbestos fibers. This made possible the inclusion of various property modifiers to aid in the braking operations (Hatch, 1970). As described in Section 6.2, this is the current method of brake lining manufacture. Any alternative material to asbestos in brake linings has to compete with asbestos's properties of strength, high temperature protection, insulation, and good frictional properties. 6.5.2 Alternatives in Brake Linings At this time, there are no commercially available, asbestos-free brake linings intended for use in automobiles with drum brakes (Aldrich, 1977; Rosenburg, 1977). This is not the case when considering disc brake pads, as will be explained later. Currently, nearly all of the major brake lining manufacturers are engaged in research and testing programs to develop asbestosfree drum brake linings for automobiles; commercial success has not been achieved. It should be noted that, if by "alternative" we mean a new or better fiber which might shortly be available as a replacement for asbestos in conventional brake linings, the chances are actually quite remote. The possible asbestos alternatives which are being tested and considered are discussed below (Hatch, 1970; Aldrich, 1977; Rosenburg, 1977): (1) Glass Fiber - overall strength is lower than that of asbestos, but strong enough for friction material applications. Unfortunately, at the temperatures reached by braking operations, glass fiber melts, even in depth below the operating surface. 95 FMSI 04930 (2) Steel Wool - compared to asbestos, the overall strength is lower and the cost is much higher. In addition, the material hardness of steel wool damages the brake drams. (3) Mineral Wools - overall strength is very low and brittle to the extent of limiting mixing processes. (4) Carbon Fiber - the main properties of carbon fibers are generally good, but still somewhat inferior to asbestos. A major consideration is the cost, which is a great deal more than asbestos. . . (5) Sintered Metals and Cermets - these materials are now being used to manufacture brake linings for railroad cars and airplanes. Eventually, these materials may be developed into practical applications for automo biles. At this time, the wear-resistance is not good enough for automotive uses and the cost is too high. There are two good reasons why the industry is attempting to develop asbestos-free products. First, there is the possibility of a govern mental ban on asbestos applications which emit asbestos fibers into the atmos phere. And secondly, asbestos-free manufacture would eliminate the need for asbestos-environmental control devices in the workplace and would eliminate a health hazard to employees, thereby eliminating a substantial expense. Some American brake lining manufacturers are currently maneuvering around the second reason above by establishing manufacturing plants in foreign countries whose pollution regulations are much less stringent than in the United States. The friction products containing asbestos can then be imported into the U.S. 6.5.3 Alternatives in Disc Brake Pads It is purely fortuitous that the friction materials used In disc brakes are designed to a stronger shape than in drum linings; that is, more or less square or circular pads of considerable thickness are supported by a metal plate of adequate thickness. Therefore, the friction material does not have to stand up to handling during assembly, does not have to withstand riveting, and 96 FNISI 04931 could, from the point of view of bulk mechanical strength alone, be made without a high loading of fibrous reinforcement of any kind. There remains, however, thermal shrinkage and thermal shock, and in order to prevent the formation of tensile cracks normal to the operating surface, a percentage of asbestos fibre is still retained (Hatch, 1970). Nevertheless, it cannot be said that the use of asbestos in disc brake pads remains a technical necessity (Hatch, 1970); in fact, commercially available disc pads have been developed for automotive uses which do not use asbestos (Aldrich, 1977). Table 6.. 9 lists a typical composition for ,this asbestos-free disc pad. Cost of the asbestos-free pad is somewhat higher than the asbestos pad. Table 6.9. Asbestos-Free Composition of a Disc Brake Pad (Aldrich, 1973) (vol. %) Carbon Iron Powder Steel Fiber Phenolic Resin 45 25 10 20 (manufactured by common methods) 6.5.4 Alternatives in Clutches Borg-Warner Corporation, a major manufacturer of clutches, is currently engaged in the testing of asbestos-free friction materials intended for use in clutches (Rosenburg, 1977). The asbestos-free materials being tested have been developed by the major friction-material producers such as RaybestosManhattan and Abex. To date, none of the alternatives tested have been as good as asbestos. 97 FN\S\ 04932 6.6 Summary and Conclusions for Asbestos Friction Applications ' (1) Chrysotile asbestos fiber is a major component of brake and clutch lining friction materials. Asbestos is used because it imparts strength, ^good friction properties, can withstand high temperatures, and is a good insula tor. (2) The annual D.S. demand for asbestos in friction products has ^historically ranged from 65-80 thousand short tons, or approximately 9% of the total U.S. asbestos demand. Projections calculated from 1972 figures released by the U.S. Bureau of the Census indicate that the shipment value of all asbestosfriction products is currently about $300 million. (3) At present, nearly 118 million pounds (59 thousand short tons) of chrysotile asbestos are consumed annually for fabrication of automotive brake linings. (4) Asbestos usually used in friction materials is chrysotile from Quebec and Vermont. Length grades 5 and 7 account for nearly 83% of the total use. (5) Approximately 35 corporations operating a total of 44 plant -establishments are currently engaged in manufacturing asbestos-friction material products. (6) The eight largest corporations (headed by Raybestos-Manhattan, Bendix Corporation, and Abex Corporation) control from 75-85% of the asbestosfriction material market. (7) Several different process technologies are used to manufacture asbestos brake linings and clutch facings. Manufacture can be accomplished by a molding process, in a dry or wet-mix state, or by a woven process. 98 FMS1 04933 (8) A wide variety of ingredient compositions are used for the fabrication of automotive brake linings. In addition to the 30-60% typical asbestos content, at least 43 different inorganic and organic compounds have been listed for use by previous publications and patent literature, as property modifiers and binders. (9) It may be reasonable to speculate that asbestos emissions resulting from automotive brake lining use may vary in concentration, depending upon the ingredient composition and the process method used to manufacture the individual lining. (10) Among the studies which have examined asbestos emissions or wear debris from brake linings, the best appear to be Rohl et al. (1976), Jacko and DuCharme (1973), and Alste et al. (1976). These studies utilized different methodologies and arrived at different results. Rohl et al. (1976) examined random samples of brake lining wear debris from automobiles used under real-life conditions and determined, by X-ray diffractometry, that 2-15% of the wear debris was asbestos. Jacko and DuCharme (1973) produced samples of wear debris by means of laboratory simulation utilizing a car on a dynamometer, with spe cially designed collection apparatus, and concluded, by electron microscopy, that the wear debris contained, on average, only 0.2% asbestos. Using real-life samples examined by electron microscopy and electron diffraction, Alste et^ al. (1976) concluded that the major effect of braking appears to be in separating bunches of fibers and reducing their average length, but not in altering their crystal structure. This disparity in results, computed by'very qualified re searchers, leads to the conclusion that additional work is required In deter mining a more consistent evaluation of asbestos in wear debris from brake linings in terms of content percentage. 99 FMS1 04934 (11) There has been no experimental study conducted which can confirm or refute the supposition that brake linings made by different companies, proc esses, and compositions may contribute varying amounts of asbestos emissions into the environment. This supposition is offered as a suggestion which may be .beneficial in the explanation of the different results obtained by Rohl et^ al. (1976), Jacko and DuCharme (1973), and Alste et al. (1976). . (12) According to Jacko and DuCharme (1973), the total asbestos contribution to the environment as a result of brake and clutch lining wear is nearly 158,000 lbs/yr, of which 5,060 lbs/yr is airborne. Utilizing the results obtained by Rohl ej; al. (1976) for asbestos content of wear debris, tfre can calculate that the total environmental contribution, on average, would be 3,420,000 lbs/yr, of which 110,000 lbs/yr would be airborne. Obviously, the differences are significant. (13) A very high percentage of the asbestos emitted in wear debris is shorter than 5 pm in length. In fact, Rohl et al. (1976) found that nearly 80% of this asbestos is shorter than 0.4 pm. This is an extremely important con sideration when dealing with exposure to workers, such as brake service mechan ics, who come into direct contact with this airborne wear debris. OSHA stand ards count only fibers from 5-100 pm in length; therefore, any measurements made by OSHA standards would seriously underestimate the asbestos exposure to the workers. Rohl et al. found that even under OSHA test standards, asbestos fiber concentrations would periodically exceed OSHA regulations during brake mainte nance and repair. Therefore, a potentially serious asbestos exposure exists for the estimated 900,000 persons employed as auto mechanics and garage workers. 100 FMSI 04935 REFERENCES Aldrich, F.W. (1977), Personal Communication, Bendix Corp., Troy, N.Y. Aldrich, F.W. (1973), Ger. Offen. 2,304,732, Aug. 9, 1973; U.S. Patent Appl. 222,342, Jan. 31, 1972, assigned to Bendix Corp. Alste, J., Watson, D., and Bagg, J. (1976), "Airborne Asbestos in the Vicinity of a Freeway," Atmos. Environ., T_, 583-9. Anderson, A.E., Gealer, R.L., McCune, R.C., and Sprys, J.W. (1973), "Asbestos Emissions from Brake Dynamometer Tests," Paper 730549 presented at SAE Automotive Engineering Meeting, Detroit, Michigan. Asbestos Magazine (1961-1976), Monthly Publication, Asbestos, Stover Publishing Company, Willow Grove, Pennsylvania. Badolette, M.S. (1963), "Asbestos," Kirk-Othmer Encycl. Chem. Technol., 2nd Ed., 2, 734-7. Bark, L.S., Moran, D., and Percival, S.J. (1975), "Chemical Changes in AsbestosBased Friction Materials During Performance - A Review," Wear, 3^4, 131-9. Berger, H. and Oesper, R.E. (1963), Asbestos Fundamentals, Chemical Publishing Company, New York, New York. Bush, H.D., Rowson, D.M., and Warren, S.E. (1972), "The Application of Neutron Activation Analysis to the Measurement of the Wear of a Friction Material," Wear, 20, 211-25. Carton, R.J. (1974), "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," February, 1974, Environmental Protection Agency, U.S. Nat. Tech. Inform. Service, PB-238 320. Clifton, R.A. (1974), "Asbestos," preprint from the 1974 Bureau of Minerals Yearbook, U.S. Dept, of the Interior. Clifton, R.A. (1975), "Asbestos," preprint from Bulletin 667 - Mineral Facts and Problems, 1975 Ed., U.S. Dept, of the Interior. Clifton, R.A. (1976), Personal Communication, Div. of Nonmetalllc Minerals, U.S. Bureau of Mines. Daly, A.R., Zupko, A.J., and Hebb, J.L. (1976), "Technological Feasibility and Economic Impact of OSHA Proposed Revision of the Asbestos Standard," prepared for the Asbestos Information Association/North America, Washington, D.C., March 29, 1976. 101 FMSl 04936 'Economic Information Systems, Inc. (1976), "Share-of-Market Report - SIC 3292 Asbestos Products," New York, New York. Fisher, E.W. (1967), "Packing Materials," Kirk-Othmer Encylc. Cham. Technol., 2nd Ed., 15, 449. Goodhead, K. and Martindale, R.W. (1969), "The Determination of Amosite and Chrysotile in Airborne Dusts by an X-Ray Diffraction Method," Analyst, 94, 985-8. Gregg, R.T. (1974), "Development Document for Effluent Limitations Guidelines and New Source Performance Standards for the Textile, Friction Materials and Sealing Devices Segment of the Asbestos Manufacturing Point Source Category," U.S. Nat. Tech. Inform. Service, PB-240 860. Grove, C.S. and Rosato, D.V. (1967), "Laminated and Reinforced Plastics," Kirk-Othmer Encycl. Chem. Technol., 2nd Ed. , 12, 189. Harwood, C.F. and Blaszak, T.P. (1974), "Characterization and Control of Asbestos Emissions from Open Sources," IIT Research Institute, September, 1974, U.S. Nat. Tech. Inform. Service, PB-238 925. Hatch, D. (1970), "Possible Alternatives to Asbestos as a Friction Material," Ann. Occup. Hyg., 1J, 25-9. Hendry, N.W. (1965), "The Geology, Occurrences, and Major Uses of Asbestos," Ann. NY Acad. Sci., 132, 12-22. ^Hickish, D.E. and Knight, K.L. (1970), "Exposure to Asbestos During Brake Maintenance," Ann. Occup. Hyg., 13, 17-21. -Holt, P.F. and Young, D.K. (1973), "Asbestos Fibres in the Air of Towns," Atmos. Environ, T_, 481-3, 668-70. Igwe, B.U.N. (1974), "Economic Analysis of Effluent Guidelines for the Asbestos Industry," U.S. Nat. Tech. Inform. Service, PB-238 268. i Jacko, M.G. and DuCharme, R.T. (1973), "Brake Emissions: Emission Measurements from Brake and Clutch Linings from Selected Mobile Sources," U.S. Nat. Tech. Inform. Service, PB-222 372. Jacko, M.G., DuCharme, R.T., and Somers, J.H. (1973), "How Much Asbestos Do Vehicles Emit?" Automotive Engineering, 81, 38-40. Keller, E.C. (1969), U.S. Patent 3,477,982, Nov. 11, 1969, assigned to Abex Corp. Kover, F.D. (1976), "Asbestos: A Review of Selected Literature through 1973 Relating to Environmental Exposure and Health Effects," Office of Toxic Substances, Environmental Protection Agency, EPA Report No. EPA-560/2-76-001. 102 FMSI 04937 Lynch, J.R. (1968), "Brake Lining Decomposition Products, J. Air Pollut. Cont. Assoc., IB, 824-6. Margolin, S.V. and Igwe, B.U.N. (1975), "Economic Analysis of Effluent Guidelines: The Textile, Friction and Sealing Materials Segment of the Asbestos Manu facturing Industry," U.S. Nat. Tech. Inform. Service, PB-250 682. Mitchell, A. (1974), "Ger. Offen. 2,409,916, Oct. 10, 1974, assigned to E.I. duPont de Nemours. Modic, F.J. and Barsness, D.A. (1965), "Embedding," Kirk-Othmer Encycl. Chem. Technol., 2nd Ed., JJ, 102-16. Nicholson, W. J., Langer, A.M., and Selikoff, I.J. (1973), "Discussion - Asbestos Fibres in the Air of Towns," Atmos. Environ., ]_, 666-8. Nicholson, W.J., Rohl, A.N., and Ferrand, E.F. (1971), "Asbestos Air-Pollution in New York City," in Proceedings of the Second International Clean Air Congress, H.M. England and W.T. Beery (eds.). Academic Press, New York, 136-9. Rosenburg, R. (1977), Personal Communication, Borg-Wamer Corp. , Des Plains, Illinois. Rohl, A.N., Langer, A.M., Wolff, M.S., and Weisman, I. (1976), "Asbestos Exposure During Brake Lining Maintenance and Repair," Env. Res., 12, 110-28. Sakata, T. , Akita, K. , Shiozawa, S., and Maeya'me, H. (1974), Japanese Patent 74 06,029, Jan. 19, 1974, assigned to Hitachi Chemical Co. Selikoff, I.J., Nicholson, W.J., and Langer, A.M. (1972), "Asbestos Air Pollution," Arch. Environ. Health, 25;, 1-13. Seymour, R.B. (1968), "Plastics Technology," Kirk-Othmer Encycl. Chem. Technol., 2nd Ed., 15, 793, 802. SRI (1974),-, "Asbestos - Salient Statistics," Chemical Economics Handbook, Stanford Research Institute, Menlo Park, California. The Asbestos Factbook (1970), printed by Asbestos (Asbestos Magazine), Willow Grove, Pennsylvania. Toyota Central Research and Development Laboratories, Inc. (1971), British Patent 1,235,100, June 9, 1971. U.S. Bureau of the Census (1972), "1972 Census of Manufacturers," U.S. Gov't. Printing Office, Washington, D.C. 103 FMSl 04938 U.S. Bureau of the Census (1975 a), "U.S. General Imports," Report FT135, December, 1975, U.S. Gov't. Printing Office, Washington, D.C. U.S. Bureau of the Census (1975 b), "U.S. Exports - Schedule B Commodity by Country," Report FT410, December, 1975, U.S. Gov't. Printing Office, Washington, D.C. U.S. Bureau of the Census (1976 a), "U.S. General Imports," Report FT135, June, 1976, U.S. Gov't. Printing Office, Washington, D.C. U.S. Bureau of the Census (1976 b), "U.S. Exports - Schedule B Commodity by Country," Report FT410, June, 1976, U.S. Gov't. Printing Office, Washington, D.C. U.S. Census of Manufacturers (1967, 1972), see U.S. Bureau of the Census (1972) 104 FMSI 04939 FMSI 04940