Document vwGZ8gJepqp55E0JMzJ0w4G9

FILE NAME Manville JMA DATE 1963-1970 DOC JMA330 DOCUMENT DESCRIPTION Brake Lining Dust Study M Research Report Media Article and Memos Research & Engineering September 8 1970 Center MEMO FOR FILE VISIT Brake TO INLAND DIVISION OF GENERAL Lining Decomposition Products MOTORS - AUGUST 31 1970 Dr. Merle Gibson Medical Director of the Inland Division of General Motors commented during the M Research Center session of the Asbestosis Course held June 15 through 18 1970 at Mt. Sinai Hospital that results of work at Inland did not agree with the data presented by Jerry Lynch on the decomposition of brake lining materials He agreed to set up a meeting with Dr. George Rappaport head of the Chemical Laboratory at Inland's Dayton laboratory to review both Inland and M research on thi project : After several brush I was able to arrange a meeting with i Dr. Gibson and Dr. Rappaport on August 31. Also present during Ue part of the meeting were Mr. G. W. Beck Chief Engineer for Ulta Inland and Mr. J. . Joel H. Overwein Assistant Chief Engineer -' Summary Dr. Rappaport doubted the validity of the general data presented by Jerry Lynch on the breakdown of brake linings After reviewing M's data and discussing peripheral information he is convinced of the validity of our data showing less than 1 per cent chryso- tile content He suggested as a final test that the biological effect of the brake lining decomposition products be determined by animal tests These may be sponsored by General Motors with Dr. Selikoff Dr. Gibson still believes asbestos to be the main cause of lung atmosphere cancer and objects to any additional input to the matter how slight I doubt if he can be convinced Dr. Gibson wae not quite frank in his discussion especially present Inland has done no significant when work on capturing and analyzing reaction products from brake wear They were planning to begin a project in the near future MEMO FOR VISIT TO FILE INLAND LABORATORIES September 8 Page 2 1970 Dr. Rappaport had been asked to comment on the validity of Jerry Lynch's results He reacted unfavorably to did not accept any conclusions because the paper the paper and 1 presented only approximate fiber concentrations 2 gave no detailed experimental techniques 3 did not define the technique for quantification of fiber content and 4 did not define the effectiveness of collecting all decom- position products He was also concerned about whether the decomposition products whatever they might be were in themselves carcinogenic The following M reference material was used as a basis for discussing our work and answering Dr. Rappaport's questions 1. Research Report 456-2506 December 19 1966 - STUDY OF :. WEAR DUST FROM BRAKE LINING written by D. Sinclair a 2 Research Report 456 June 13 1968 - WEAR PRODUCTS FROM BRAKE LINING written by S. W. Wegrzyn 3 Research Memo M456-386 November 8 1967 - COLLECTION OF WEAR DUST FROM AUTOMOTIVE BRAKE ASSEMBLY DURING INERTIA DYNAMOMETER TEST written by W. R. Randolph 4. Research Report 404-67 August 3 1970 - METHOD FOR THE QUANTITATIVE DETERMINATION OF CHRYSOTILE FIBER IN SAMPLES FROM VARIOUS SOURCES written by A. F. Burns K. L. Jaunarajs and G. P. Reimschussel test apparatus and techniques with special the millipore system of collecting samples nown efficiency in collecting all particulate decomtion products 2 The techniques for quantifying fiber including the previous point count method and the more recent radioactive tracer method : 3. The quantitative test data showing that 50 to 80 per cent of the wear products were collected as either airborne or in the box samples MEMO FOR VISIT TO FILE INLAND LABORATORIES September 8 Page 3 1970 4 Analytical data on both the airborne material and the com- posite material illustrating the collection of all residual products from contents decomposition of asbestos equal Mg0 and Si02 5 Pictures of airborne and total composite samples 6 Discussion of amorphous material vs fosterite in the decom- position products with different severity of wear as evi- denced by average drum temperatures of 175 330 and 550F respectively 7 Actual detailed chrysotile contents in the various samples and their relationship the chrysotile content in the ori- ginal product We he also discussed certain subjects was particularly interested in which Dr. Rappaport These included indicated 1 Asbestos bodies vs ferruginous bodies 2 Factors influencing respirability of fibers including Timbrell's work and recent Battelle work on retention of extremely fine particulate matter 3. The proposed programs on the effect of fiber diameter fiber length and aspect ratio including M programs Webster's work and others Dr. Rappaport was particularly concerned with the effect of particle size and fiber diameter of the decomposition products and its relation to respirability 4 Extraction of minerals from lung tissue including low tem- perature ashing and hydroxide of Hyamine treatment After a full morning's discussion Dr. Rappaport indicated to Messrs Beck Overwein and Dr. Gibson that he was satisfied the decomposition products in fact contained only very small quan- tities of chrysotile He suggested the desirability of conducting tests to show that these decomposition products were not biologi- cally harmful and calculating the actual net input of chrysotile to the ambient air from the decomposition of brake linings based on our data and known brake lining statistics We have already recognized the complexity of such an undertaking in our calculations on the fiber contributed by decomposition of asphalt asbestos paving For example how much fiber is removed per day from the atmosphere by fall rain wind migration etc. as compared to the input from any source of contamination MEMO FOR VISIT TO FILE INLAND LABORATORIES September 8 Page 4 1970 General Motors through Dr. Gibson is seriously considering funding work at Mt. Sinai but no specific program has apparently been defined Inland personnel were invited to visit us at the Research Center at any time to discuss the problem and any of their suggested programs I will send Dr. Rappaport those portions of the mentioned Research reports which can be released without disclosing proprietary information Dr. Gibson is still a firm believer that asbestos is the major positive cause for lung cancer I think he is overpowered by the Selikoff mystic and that it is worthless to try to convince him otherwise then by direct statements from Dr. Selikoff However the others present at the meeting could probably be convinced that no problem exists by a few animal experiments with calcined asbestos calcined serpentine and brake lining wear material L. E. H. J. W. R. M. L. M. Hutcheson Jackson DH Pundsack R. Blair Att J. Dec M. Fenner G. P. Donovan _ Leineweber C. Streib Asbestos Plant F. L. Punds Research March 6 and Engineering 1967 Center File 259-1 Study of Wear Dust from Brake Lining Excerpted from Dr. David Sinclair's Report 456-2506) We request permission to send the to Mr. J. R. Lynch Public Health Cincinnati Ohio attached excerpts from this report Service Laboratories 1014 Broadway Mr. Lynch has carried out a study of brake lining wear dust using speci- mens collected under a variety of test conditions at the laboratories of the American Brake Shoe Corporation at Mahwah New Jersey His results are in general accord with those of David Sinclair Mr. Lynch observed abe very little stops which if any residual chrysotile deteriorated the resin and fiber except in the allowed the release case of a : of panic few fiber wt clumps During S. Speil's visit to the Public Health Service Laboratories Cincinnati Ohio on December 7 and 8 1966 Mr. Lynch indicated that he intended to publish his data as soon tunity to include any substantiating as possible He welcomed the oppor- data which Manville might be able to furnish We believe that the publication of information pertaining to the breakdown of chrysotile fiber during the wear of brake linings would be more convincing and would receive more publicity if presented by an unbiased source such as a government laboratory than by Manville May we have your permission to send this excerpt to Mr. Lynch espeil mef Enclosures S. Speil Bink \ Bink = G. Koch * Oo, be seamnait thelr elle, Ste re chaks. Principal Ingredients Many M Automotive Friction Materials Phenolic resins phenol cresol Cashew nut shell polymers long type Butadiene Sulphur polymers Rubber accelerators and some xylol used chain phenolics synthetic rubber 5 < Asbestos fiber Microcel 1 Barytes Zinc oxide Lead oxide litharge Carbon black Graphite Anthracite coal 4! Brass : Zinc _ Lead Copper Coal froducts in in automotive aste automotive lungs & indented indented - warleion te rae 8 Cefore wow sewe Cefore 1945 a e vtadnt 3 phate - + Seaslie ee e Ut. sigan pea Luced filter 1 both outlet outloe utlettoutlet filter filter an word word on flite brake brake vs ra Dr. K. W. Smith - GH ae Research and Engineering Center November 27 1963 File 456 Brake Lining Wear Dust I am enclosing three envelopes of the following cars containing dust removed from the brakes Car Lining Mileage Comet Newport Chevrolet 2308 594 1618 Inlite equipment 1266 miles 540 miles . 9900 miles 1 : You will find that the dust consists partly of ferrous particles presumably abrasion products from the cast iron brake drums The remainder should be predominantly abrasion products from the brake lining themselves We the brake linings used can supply information in the first two cars on the composition The third car was of equipped with competitive lining a composition not known to us but undoubtedly containing asbestos fiber : . . GK CC W. C. Streib C. L. Meserve a H. G. Koch wen eee pie eS NOMA ew ete gee mA tyes nen = Ey MCD eng as rete Tre on sem ie, eee me A : D. E24197 Rearch December December & Engineering 1563 13 1563 Center Brake Lining Wear Dust You will recall that during his recent visit to the H. 17. Shigh mentioned & recent theory that asbestos Research Center Do. fibers freed in the wearing of brake linings might might have so pathological effects Mr. Koch Es obtained woor Custs from three cora and I would appreciate your on- toxining these microscopically to see if you can identify asbestos fibora in this material Work I tuching a work request ID 345 to cover this I am your your Your also attaching the pertinent correspondence and would like to call attention to Dr. tests ~~ Smith's request for the material remaining after : , . * Would you please at which time va let me know then you have completed your can again get together with Dr. Smith to any additional work is required examination determine it Pe r Wy C. Streib ew Tye cas % | Rem ea Me aged . - ne Ma . . Bek , g Research and Engineering Center March 14 1967 File 259 F. J. Solon - GHQ Brake Lining Wear Dust Attached is some explanatory correspondence from Bill Koch and Sid Speil requesting permission to release certain informa- tion on the study of wear dust from brake lining to Mr. J. R. Lynch of the Public Health Service Laboratories A copy of the informa- tion which they propose to release is attached too a ee Sdn I would like to have should be released your opinion on whether or not this information | ae Enc Pundeack F. L. Pundsack Bot . Pte . P.S. Would you please return the two photographs attached to the report These are the only copies we have at FLP vo FJS- Fyrstal Fyrstal Fyrstal Fyrstal Fyrstal Fyrstal -08 conmy Research & Engineering September 30 1970 Center cSheckler DH BIOLOGIC EFFECT OF BRAKE DRUM WEAR DUST On page 10 of your recently distributed history of M health research you state Also in July 1968 the Industrial Hygiene Foundation completed work on another research project for Manville -- a study of the effect of automobile brake dust on the lungs of laboratory animals This research showed that brake dust is biologically inert producing minor reversible lesions of the lung when injected into the trachea of rats and hamsters Drs Gibson and Rappaport of the Inland Division of General Motors are very much concerned whether brake drum dust produces any biologic effect Dr. Rappaport indicated to me that he was satisfied that brake wear was not a significant contributor of chrysotile to the atmosphere based on our documented work at the a copy Research Center of my memo on my For your information I recent visit to Inland am attaching Inland was considering establishing a program with Selikoff to study the effect of brake lining wear dust If the results of Dr. Gross work were made available to them I believe they would be satisfied If this information has been reported by Dr. Gross I would appreciate receiving a copy of it with your permission to forward it to Inland Division of General Motors S. Speil rs Attachment GHQ November 4 1970 S. Speil - Research BIOLOGIC EFFECT OF BRAKE YOUR LETTER OF 9/30/70 DRUM WEAR DUST I have reviewed the files in relation to the work reported in the History of Manville Health Research The report referred to was a Preliminary Study of Brake Dust Comparative Pathogenicity by Dr. Paul Gross dated February 14 1967. I am enclosing a copy of this report for your file and distribution to Drs Gibson and Rappaport of the Inland Division of General Motors if you consider it to be useful CLS saw Attach i { Research November & Engineering 5 1970 Center cL. Sheckler NOV 9 1970 BIOLOGIC EFFECT OF BRAKE DRUM WEAR YOUR LETTER OF NOVEMBER 4 1970 DUST Thank you very much for sending me Paul Gross report on the Preliminary Study city of Brake Dust Comparative Pathogeni- I do not intend to send this to Drs Gibson or Rappaport since the conclusions arrived at in this report cannot in any way be related to the problem of carcinogenesis They refer instead only to the effect of the material on the connective tissue that is the fibrotic effect Thank you again for sending me this information a a Research and Engineering Center June 2 1967 Researc Asbestos in Brake Linings Details of the investigation to which you refer are 670511 Chemical Changes at Brake Wear Surfaces by T. P. Schreiber included in SAE paper H. L. Gatrell and A group of interesting papers were presented at the same meeting most of GenbyeGr ena erl al Motors Technical Center people Although copies of several of these papers are in eirculation they are of such interest to so many several our men that I m asking Miss Kinder to order as many of then as are pre- sently available They can be routed to you first and I would apprecis a chance to read them after you have looked them over A list of the papers followi 670501 670502 Conditions Upsetting Brake Lining and Drum Compatibility A. W. Kiekel Carlisle Corp. Irake Linings as Related to Brake Performance ~ 1. E. Felson Abex 670509 TheThe Story of the Beta Group - An Unusual Organization Working on Brake Lining Problems 1. E. Antheil Inland Mfg Div 193 670510 = Laboratory Evaluation of Braka Lining Materials - A. J. Burkman m^7. F. Highley Engrg Staff /NG 670511 Chemical Changes at Brake Wear Surfaces - 670512 670513 679514 =New Devices to Assist in Friction Material DeveLayment - Hichard Nusechuk Inlan^Mfg D^vGu element of o Stick Meaturing Device for cratory False Evaluation of kreke Linings - cratory cratory False lon of Infrared Spectroscopie und Gas Chromatographic Techniques to Brake Lining Development GeoVragse Rappaport and Gerald Goldfinger Inland Hi 8. Speil -a- June 2 1967 I agree that it would be well to disews in det wita h Mi essl rs Gatrell and SchreiberSchreiber the work which which they reporitneNd o. 670511. I know that you are particularly interested in the techniques for examination of char film as well as the effects of thermal degradation on asbestos I would be particularly interested in getting their views on a basic research which I would like to carry out at this location into the mechanism of friction fade and reGOTETF We believe that these are related to the formation of the Labor in a Dett roio t or n ai ny e of s the following days July 20 21 25 26 and 27. I would also be available on these days and would like to asscmpany you Sines I will be may for the next three weeks I am asking Kank Gilbert by copy of this letter to try to set up a date with General Motors through our ee: I. M. Jackson ~ F. L. Pundsuck K. L. Kinder J. Des 1. W. Gilbert File Dl H. O. Lock Another idea came from New York state comptroller Arthur Levitt He asked that the laws be changed so the Government could set price ceilings on drugs essential to human life This would permit drug developers to recover costs and get a reasonable return on invested capital and outlaw what he considers excessive profits Witnesses at next week's hearings will probably be several physicians and Dr. Richard Burack of Harvard He is the author of a new book Handbook of Prescription Drugs which purports to describe how the drug industry is gouging the public Sweat components skin lipids are mosquito repellents Lactic acid a normal constituent of human sweat and skin lipids act as mosquito repellents The acid is one of three sweat components that repel the insects when tested in an olfactom eter Dr. W. A. Skinner executive director of life sciences research at Stanford Research Institute Palo Alto Calif told the ACS Santa Clara Val- ley Section Identity of the other two is being investigated Dr. Skinner heads a four team at SRI that is seeking to pinpoint naturally occurring mosquito repel- lents and attractants in man He is working in conjunction with a group at the University of California's medi- cal center in San Francisco under Dr. Howard Maibach That group is spearheading the entomological and dermatological aspects of the problem Development of improved methods that will safeguard man from mosquito bites is the goal of the study Tie Collecting sample between sweat and skin Spids The U.S. Army Medical Research and Development Command is sponsoring the project It is part of a broader study aimed toward control of mos- propagated diseases It's now clear that some people are more attractive to mosquitoes than others Dr. Skinner says Compon- ents of sweat and skin lipids may be the key to this phenomenon he notes The UC group devised some novel monitoring techniques One of these consists of noting the number of sec_ onds that elapse before three out of six to C range are repellents the highermolecular fatty acids are not Identity of the attractants and re- pellents will be a major step toward devising better methods of preventing mosquito bites Dr. Skinner says A topical or a systemic repellent may evolve from this knowledge Or we may be able to devise a diet or de- velop a drug that will influence pref- erential biosynthesis of the natural re- pellent materials _ mosquitoes enclosed in a screen cage probe when the screen is ex- Break period improves actly 1 cm above the forearm of the person being tested The reading is the probe time for the indi- vidual The medical center team has been running PT 50 measurements on a large sampling of people Values range from 10 to 40 seconds for most A small percentage of those tested show a PT 50 reading below 10 seconds they are very attractive to the mosquitoes while some rate higher than 40 seconds they are less at tractive Another device used is a small cage olfactometer which consists of 2 screened cage with two inlet ports through which a stream of air passes The air going through one of the ports first sweeps over a sample of sweat or skin lipid Mosquitoes in the cage veer toward or away from the latter stream depending on whether they are attracted or repelled by it Factors that both attract and repel mosquitoes occur in human sweat The balance of the two types of components probably varies in different individuals which would account for the different degree of attraction to the pests Dr. Skinner hopes that gas chromatographic analyses now under way will reveal the identity of the agents There is an interesting tie between the lipid repellency and the sweat attraction factors Dr. Skinner performance of brake linings | An analytical chemist and a physicist at General Motors research laborato- ries have found with the aid of elec- tron microprobe analysis and infrared spectrophotometry why auto brake linings work better after a break period than before The improved performance is due to a calcined as- bestos layer that forms on lining sur- faces after a little wear The GM work also shows that experimental preconditioned linings containing added calcined asbestos work better reg- ular linings chemist R. L. Gatzell told a Chicago meeting of the Society of Automotive Engineers The research is part of a company wide effort to develop improved frictional materials particularly for or- ganic disk brake linings GM and other brake engineers have long known that brake linings develop a thin dark layer sometimes called a char layer during the break period Mr. Gatrell explains But they have not known what this layer is In explaining the choice of the elec- tron microprobe technique Mr. Gatrell says that the method is uniquely suited to studying very thin films In addition to giving a view of the sur- face like an electron microscope does it also chemically analyzes the surface Also it probes only 1 to 2 microns into a surface says For example the SRI workers find that a person with a sweat composition that attracts mosquitoes_us- mosquitoes_usually has a lower concentration of re- pellent in his skin lipids In addition to the identification of lactic acid the study points up a number of other clues to the structure of Using this method physicist T. P. Schreiber examined cross sections of samples of worn lining He found a surface layer with a higher electrical conductivity than the substrate in areas where asbestos constitutes the lining surface This layer is about 8 mi- crons thick naturally occurring repellents Examples include Liquid extraction with di ethyl ether of sweat at pHl yields a highly repellent fraction containing a mixture of hydroxy fatty acids besides lactic acid Triglyceride Triglycerideand unsaturated hy drocarbon fractions in skin lipids show endence of repellency Skin lipid Fatty aids in the Ca The GM workers also observed that when the electron beam was focused for 30 seconds or more on a substrate area containing asbestos the area's conductivity increased until it resem- bled that of the surface layer As no chemical change could be detected they assumed that heat generated by the electron beam had decomposed the asbestos As^> estos when heated 1 1478 K. Nece spises into fea ' noel Pocata poaetf os aba forsterite The Misrkies Misrkies then turned to I tiysis to examine worn matemal In a borke lining to see if it did indeed contain calemed asbestos They implored the IR spectra of the debris with that of commercial asbestos and dead 1 dead dead asbestos They found that 370 an lab spectrum has a aracteristic of band at the cal- Aped material material Fellesung up this fudnig experimentad mangs were made intaining and 30 of calcined asbestos added to regular lining furandation Laboratory friction tests showed that the base Huling fidel started to lose frictional properties 600 P The 28 8 20 test samples showed im- proved performance performance before they were Broken in Bor instance the 20 sam- de showed a distine recovery in its efficient of friction at 550 F. during its first test When fully broken in dl three test samples showed bet ter frictional properties over a wider cange of temperatures than did the base material Mr. Gatrell expluus that further and more prolonged laboratory tests eventually proved the sample with 20 as- bestos to have the best and most con- sistent properties He says these tests were so encouraging that this lining has been tested in field runs It has performed satisfactorily in both country country and in the mountains level _r containing inorganics in paper may play cancer role Selenium in one of the inorganic compounds is most toxic substances known and may be an important cause ot lung cancer and emphysema says Dr. Philip W. West of Louisiana State University Selenium is found in rela- tively large quantities 10 p.p.m. cigarette paper and to a significant degree - 5 most other kinds of paper Smoking thus may be the immiediate danger some people but bung of trash containing a large amount of paper could affect non- smokers too he told a joint meeting of the Biton Rouge sections of the Amer- ant bemical Society and American Institute of Chemical Engineers He zereived the annual Charles E. Coates femoral Award at the meeting 10 West says his coelisions are Bodom prelammary studies of seles in tobacco and papers Numer- Vacthes Palies ane needed Ne wih out These Bould include include develop of additional anafyal anafyal methods teat Vodenpeon : ompornids Costes award winner West 6.5 p.p.m. selenium in EN nal combustion engines and ways for ultimate disposal of any captured se- lenium compounds At present other work is under way Dr. West notes One study by Dr. James P. Lodge Jr. of the National Center for Atmospheric Research Boulder Colo involves aerosol pro- duction of some of the various forms of selenium The aim of this work is to find the proper particle size range for use in animal exposure studies Another area involves study of how effective cigarette filters are in removing selenium . . So far some 70 different kinds of paper have been investigated at LSU and found to contain selenium The selenium content varies widely with the type of paper Typical newsprint has 4 p.p.m. selenium mimeograph paper 0.7 p.p.m rice paper 5.6 p.p.m. paper towels 1.2 p.p.m a bond paper 1.4 p.p.m. and stock that EN is printed 45 p.p.m. Tobacco in made cig ttes has between 2 and 4 p.p.mm. selenium much less than does the paper Two kinds of cigarettes made it the U.S.S.R. U.S.S.R. had 6.8 and 6.4 p.p.m. of selenium in the papers and 0.8 and 1.4 p.pm. of selenium in the tobac- cos Paper used to wrap some U.S. cigars contains more than 10 p.p.m. selenium Selenium probably contes West into lungs as the dis or trioxide Dr. West SAY'S Then in the presence of water it becomes selenious or selenic acid No data are avaiidile on the cumula- Bye Bye fleets of Pissries selemann compounds on The method which Dr. West and dos enckers use ta determine sele- sun the ring wen tochique A Real esandal esandal black is med in filter papers Color and its inten- sity identifies the selenium and indi- cales quantities present Selenium has long been known to be very toxic Hydrogen seleride for example is about 200 times more toxic than hydrogen cyanide Dr. West says Selenitun oxychloride is such vesi- cant that it reacts violently with hu- man skin and forms a burn or open lesion In the U.S. the maximum al- lowable concentration of selenium in potable water has been set at 50 p.p.b. Selenium is found in significant quantities in soils in the Rocky Mountain states and western plains states Vegetation growing in soils of rela tively high selenium content may concentrate selenium in them Cigarette papers are made from flax straw which is grown west of the Mississippi River where soil selenium is relatively high This can account for the high amounts of selenium found in cigarette pa- pers Some plants require selenium for growth these are called selenium indicator plants They may concentrate selenium in their tissues 100 times or more above that of the soil in which they grow Selenium's effects on animals has long been noticed although the effects have been only recently attrib- uted to selenium alkali disease or in cattle have been Blind staggers praying disease noted as far back as the 13th century when some of Marco Polo's animals suffered from alkali disease in western China after eating seleniferous vegetation that is now known to grow in that part of the world Scientists Scientists are duo investigating investigating sela nion the xmosphere T r Research & Engineering Center May 29 1967 File 456 Asbestos in Brake Linings incorporating You may already have seen the attached brief issue Insofar as the summary from EN May 29 1967 possibility of improving brake lining by calcined chrysotile is concerned this is a matter for However I microprobe was and particularly intrigued by the reference infrared analysis to study the your research to the use of people electron worn brake lining think dark char layer on the enstatite R. L. Gatrell and T. P. Schreiber of the General Motors Research Laboratory have come to the same conclusion that we have namely that the debris from the brake lining was similar to that of calcined : they found that the debris asbestos The article states spectrum has a band infrared at 870 cha- ratteristic of the calcined material Although they state that asbestos when heated to 1470F decomposes into four materials forsterite and water they do not quartz to identify any one of these specifically state that they were able compounds individually in the product If you have good contacts with the up a meeting to discuss their work GM Research Center you may want and their results from to set point If so I would like to a scientific stand- participate If you do not have good contacts r / 00 H. Jackson DE 8. Speil Dr. K. W. Smith - 2nd Floor Division Headquarters November 4 1964 a rae, A a As per our discussion herewith is a list of the ingredients generally found in M automotive friction materials ~ MANVILLE RESEARCH AND ENGINEERING CENTER Report 456 . Date January 20 1964 Title PETROGRAPHIC AND RAY DIFFRACTION ANALYSES OF BRAKE LINING WEAR DUSTS Requested by W. C. Streib .- Request No. 345 e & F 5 SUMMARY Ls . Three samples of brake lining wear dust were examined petrographically to determine - whether chrysotile fiber can be distinguished in this type of material Two of the samples were also examined by ray diffraction for confirmation The samples were from the following brake linings 0 fay OO 1 1963 Comet 2 1963 Pontiac 3 Chevrolet 6 Inlite Lining . Coed ot TS Petrographic examination the showed following : : The dust from the Comet lining contained an organic binder plus small percent^ges of quartz magnetite carbonates talc and rarely a few chrysotile fibers a recognizable Chrysotile of constituted per cent in sizes the total under the microscope less than one Boy re t = The dust from the Pontiac lining appeared similar to the one from the Comet liningae showing the same components in comparable amounts Only an occasional bundle of chrysotile fiber could be detected after prolonged examination of The Chevrolet brake lining dust differs somewhat from the others several in that . slides 7 Uh it contains possibly 10 per cent quartz | Talc appears to be absent - A small amount of graphite ; appears to be present but was not positively identified An occasional small bundle .. 4 of chrysotile fiber was noted as in Samples 2. 1 and : ray diffractionresults { . ote re a5 , Lin g Dust fromComet Lining y : quartz weak pattern chrysotile . trace tale sey.) trace .. magnetite - . + trace ee a + v ; Bat . te ; quartz major ? 7 Dust from Inlite Lining 4 Dye of Chevrolet magnetite =. trace 4 detected lining dust The trace of chrysotile by ray diffraction in the Comet could possibly amount to as much as 5 per cent of the total This would indicate that in addition to the occasional fibers seen microscopically there may be some 4 Notebook No. 2910 p 52 2864 p 88 bo File 456 MANVILLE RESEARCH AND ENGINEERING CENTER Report No. 156-7-85 156-7-85 156-7-85 Summary Page 2 finely divided and possibly coated fibrils not recognized recognized under the 2 recognized Scope Failure of ray diffraction to detect detect detect detect any chrysatile in the tf: lining dust sets the chrysotile content of this comples The Pontiac lining of microscopically comple was not examined recognizable chrysotile by in X this this in the Comet sample . Contents Summary only Approved by Pundsack Pundsack gf Pundsack F. I. Fundsack Reported by repudicaton ray DiffractionDDiffriactiofn Difffractrion action by Of repudication or 3. P. Hourly USINditon eh . USINditon Cc K. W. SmiGt H ah n. -.; KUROFIL NOJO NOJO LAL ALALANI ALALANI MAN MAN F. Rassweiler C. Smith 3 L. Pundsack C. Streib G. Koch Bailey P. McGourty Library 2 GH J^ with with CCoommppllyyiinngg phone your Through May your request request request request in -- May 6th , I seaided .com- of technical notebooks covering covering microscopy microscopy for 1964 1964 and 1965 Iregretregret that that - no record covering covering youryour informal request request for examination of _ brake brake dust lining recall was made However I do optical magnifications magnifications -dust -dust microscope microscope microscope _ . --, via the optical 500x 500x , optical and was method the to dfetiecbtrous i by could be used detect shown to be at unable the the examining _ the . magnifcations magnifications unable defect defect eS to Met | anything  June June 1445- 1445- 1445- 1445- 1445- Principal Ingredients In Many M Automotive Friction Materials Phenolic resins phenol cresol Cashew nut shell polymers long Butadiene type polymers Sulphur Rubber accelerators and some xylol used chain phenolics synthetic rubber 58 123 Asbestos Microcel fiber Barytes Zinc oxide Lead oxide litharge Carbon black Graphite Anthracite coal Brass Zinc : Lead Copper . Me . y boal tax automotive undertical lungs asts take impregnation froductisn impregnation inducted - impregnatibonefore 19th now used only in 11/4/64 General Headquarters August 2 1967 9. Speil - Finderne Asbestos Health Meeting - July 6 File 259 As you requested I have attempted to identify the origin of the brake lining dust samples which were forwarded to Dr. Paul Gross of the Industrial Hygiene Foundation I have been unable to find a specific reference to the shipping of respondence the dust attached to Dr. Gross but the may give a clue as to copies of what was cor- ultimately forwarded ano 001 PF. a Pundsack Finderne H. M. Jackson x. ANTE ee ... %, Streib Research Bicke Lining Near Dunb Ton on have received a copy of H. G. Koch's letter to me on November 27 2052 thy sabject on forwarding the three endopna ing the das I fromalysia As discussed on my reach visit this duct named to see 22 the are any free in it If there is my dust lof's car ~ might like to have used by our research pathologist pathologist on , the Industrial Pygions Foundation in Pittsburgh . Foundation - . . I shall be very pleased to visit yen again at the Center to discrea tim results of your tests when obtained ; 4 ; oy a 4 t i 3 a : z ae *, CC H. O. Koch Research ; a . - ' a s a : . t Engi & n Ene gine eerr ingiCn entg er Besember 13 1963 Brake LinWi hern Bug st suinoibngtained attachtinhgeovryisit sygreciate pathological fibers yourattention Would againtogether corespondanos remining August 27 1971 / Dr. Joseph H. Sommers National Air Pollution Control Division of Motor Vehicle D 5 Research Drive Ann Arbor Michigan 48108 Association Dear Dr. Sommers Dr. Michael Jacko of Bendix Corporation visited the Research and Engineering work on wear of Center on August 17 to discuss brake linings and to review in our previous general terms only his proposed research protocol for his contract with your ness group and the We were much fact that he impressed with Dr. had become so well Jacko's thoroughgrounded in the problems connected with the contract in May this project since the awarding of During his visit we reviewed several reports based on brake test work at the Manville Research & Engineering Center The thrust of this work was essentially to prove to our own satisfaction and to the satisfaction of Public Health Service personnel that most of the asbestos in drum brake linings is destroyed during normal usage The resultant inorganic product is it chemically the same but physically and crystallographically is entirely different and insofar as we know is not bio- logically active A careful review of the data presented in these reports cate recoveries of material on an inorganic basis of 50 indito 80 per cent which was entirely satisfactory insofar as the basic requirements of our effort I am sure that more sophisticated analyses and more careful sampling by Dr. Jacko will yield better material balances but I believe his conclusions con- cerning the destruction of chrysotile will resemble our own I am enclosing copies of the following as the basis for our discussion reports which served 1. Report 456-2506 - Study of Wear Dust from Brake Lining August 27 Page 2 1971 Dr. Joseph NAPCA Ann Sommers Arbor Michigan 2 3. 4 Report 456 Memorandum M456-386 Report 404-67 - Wear Products from Brake Lining - Nature of the Material - Collection of Wear Dust from Auto- motive Brake Assembly During Inertia Dynamometer Test - Method for the Quantitative Determi- nation of Chrysotile from Various Sources Fiber in Samples These can be used by your organization or any personnel associated with this specific contract I would prefer that they not be divulged to others without our permission On this basis you are free to send them to Dr. Jacko for his use . As I expressed to I would very much you during our phone like the opportunity conversation to visit Dr. in the past Jacko's laboratory and if possible discuss his work with him in more specific detail as soon as actual progress warrants such a meeting : Sincerely Dr. Sidney Corporate Speil Mining Director & Pipe Divisions rs Attachments 4 bcc C. Sheckler J DH F. L. Pundsack E. M. Fenner J. H. Zettel J. Dec J. P. Leineweber " SANTA BARBARA CALIF NEWS PRESS S. PRESS 36,500 H | , if MAR 28 1968 Applying Brakes Might Also Be Releasing Cancer Agent SAN DIEGO ( - Every shown asbestos in the lungs of Dr. Anderson said lung cn- time you hit your brakes you may be polluting the air with up to 50 per cent of cross sections of the population Dr. cer jor which he called the cancer problem in mathis a substance suspected of caus- Anderson said in a report giv- country may be caused by ing cancer a pathologist says The substance is asbestos widely used in brake lining It also is found in roofing insulation and many other in- dustrial materials Dr. W. A. D. Anderson of the University of Miami School of Medicine has found tiny as- bestos fibers in the lungs of 31 per cent of the men and 20 per cent of the women in a group of 500 persons studied at random in Miami en to a symposium for science writers sponsored by the American Cancer Society An increased incidence of lung cancer workers has among asbestos been noted for years he said The magni- tude of asbestos exposure in general urban populations has only been recently document- ed . - many substances In - addition to asbestos he cited cigaret smoke and automobile ex- haust The evidence that cigaret smoke contains a lung cancerproducing factor is overwhelming he said but success so far in changing this exposure factor in the general popula- tion cannot be described as- overwhelming or even good Surveys in other cities have storyAAP P GROUP Best Quality Posible From SupliedOriginal CORPATION REPODUCTIN MERIL DOCUMENT we eee aenea TUCSON TUCSON ARIZ D. 41,909 MAR 28 1968 s E1 SvANery Time You Hit Your Pollution | time DIEGO AP - Every you hit your brakes you may be polluting the air with a substance suspected of caus- ing cancer a pathologist , says The substance is asbestos widely used in brake lining It also is found in roofing insula- tion and many other industrial materials Dr. W. A. D. Anderson of the University of Miami School of Medicine has found tiny asbes tos fibers in the lungs of 31 per cent of the men and 20 per cent of the women in persons Miami studied a group of 500 at random in Surveys in other cities have shown asbestos in the lungs of up to 50 per cent of cross sec- tions of the population Dr. Anderson said in a report released at a symposium for science writers sponsored by the American Cancer Society An increased incidence of tude of asbestos exposure in general urban populations has only been recently docu mented Dr. Anderson said lung cancer which he called the ma jor cancer problem in this country may be caused by many substances In addition to asbestos he cited cigarette smoke and automobile exhaust lung cancer among asbestos workers has been noted for years he said The magni The evidence that cigarette smoke contains a lung cancerproducing factor is overwhelm | ing he said but success so far in changing this exposure factor in the general population cannot be described as over- whelming or even good Dr. Anderson says his labora- tory has been able to produce lung cancers in rats and mice similar to those which occur in man by long exposure to air containing one or two parts per million of a olefin sub- stance This substance he said has been found in engine exhaust ; CULVER CITY CALIF NEWS D. 6,000 , 27 19618 968 &M% Car brakes linked to cancer air pollution in urban areas ! SAN DIEGO AP - Every time you hit your brakes you may be polluting the air with a substance suspected of causing cancer a pathologist says The widely substance is lining asbestos used in brake lining It also is found in roofing insula- tion and many other industrial materials Dr. W. A. D. Anderson of the University of Miami School of Medicine has found tiny asbes tos fibers in the lungs of 31 per cent of the men and 20 per cent and automobile exhaust million of a olefin sub The evidence that cigarette stance This substance he said smoke contains a lung cancerproducing factor is overwhelm jing he said but success so far in changing this exposure factor in the general population cannot be described as over has been found in engine exi methods haust None of our present mor- of diagnosis and treatment made any real dent in the mor- tality from lung cancer Unless whelming or even good something new not presently ev Dr. Anderson said his labora en on the horizon is discovered tory has been able to produce in diagnosis or therapy the lung cancers in rats and mice answer to the problem of lung similar to those which occur in cancer must lie in studies di air man by long exposure to rected to causation and preven- containing one or two parts perition perition i of the women in a group of 500 persons studied at random in Miami Surveys in other cities have shown asbestos in the lungs of up to 50 per cent of cross sec tions of the population Dr. anderson said in a report released today at a symposium for science writers sponsored by the American Cancer Society An increased incidence of lung cancer workers has among asbestos been noted for years he said The magni tude of asbestos exposure in general urban populations has only been urban recently populations docu- mented I Dr. Anderson said lung can major cer which he called cancer problem in the this coun- try may be caused by many substances In addition to as- bestos he cited cigarette smokel SANTA MONICA CALIF OUTLOOK | D. 30,000 MAR 27 1968 blamed Brakes Exhaust blamed Cancer Tied Tied To Traffic Products | , SAN DIEGO AP - Every time you hit your brakes you may be polluting the air with a for science writers sponsored by the American Cancer Soci lety Asbestos Factor substance This substance he | said has been found in engine exhaust None of our present meth- substance suspected of causing cancer a pathologist says The substance is asbestos widely used in brake lining It also is found in roofing insula tion and many other industrial materials An increased incidence of lung cancer workers has among asbestos been noted for years he said The magni- tude of asbestos exposure in general urban populations has only been recently document ed - ods of diagnosis and treatment have made any real dent in the mortality from lung cancer Unless something new not presently even on the horizon is discovered in diagnosis or therapy the answer to the Dr. W. A. D. Anderson of the University of Miami School of Medicine has found tiny asbes- tos fibers in the fungs of 31 per cent of the men and 20 per cent of the women in a group of 500 persons studied at ran- dom in Miami Surveys in other cities have shown asbestos in the lungs of up to 50 per cent of cross sec- tions of the population Dr. Anderson said in a report re today leased today at a symposium eased at Dr. Anderson said lung can- problem of lung cancer must cer which he called the ma tie in studies directed to causa- jor cancer problem in this tion and prevention country may be caused by The best hope for preven- identifying substances In addition tion he said is in | many cigarette to asbestos he cited and changing those things in which cause smoke and automobile our environment haust . cancer The evidence that cigarette smoke contains a lung cancer- producing factor is overwhelm- ing he said but success so far in changing this exposure factor in the general popula- tion cannot be described as ov- erwhelming or even good Auto Exhaust Tests Dr. Anderson said his labo- ratory has been able to produce lung cancers in rats and mice similar to those which oc- cur in man by long exposure to air containing one or two parts per million of a olefin MANVILLE P.O. BOX RESEARCH & ENGINEERING CENTER 159 MANVILLE NEW JERSEY * TELEPHONE 201 RANDOLPH 2-9000 March 6 1967 Mr. J. R. Lynch Public Health Service 1014 Broadway Cincinnati Ohio Laboratories Dear Mr. Lynch During your recent visit Sinclair's report on the whether you might have a you one to this laboratory I reviewed with you Dr. David study of wear dust from brake lining You asked copy of this report and I promised to try to get On checking I learned that it is contrary to our present policy to release complete copies of our official laboratory but I have obtained permission to send you reports to outside organizations the attached excerpts I think that you will find that they contain all of the essential data and infor- mation which you require I hope that you will let us know whether we can help you further in pro- viding additional details for use in the paper which you are preparing and that you will keep us in touch with your plans regarding when and where you intend to present the report HGK mef Enc Cc F. L. Pundsack S. Speil -Enc J. Dec -Enc -Enc Very truly yours HG Koch W. C. Streib Research Brake LinWi earnDug st received Koch's the on asbestosubjecItHygiene isiseinet . I sha bel vel ry pleased to visit you again at the Center to discuss the resuol f t yos ur tests os H. G. Koch Research KamutWh. and th ... Se e egy 11/2 Research and Engineering Center November 27 1963 Dr. K. W. Smith GH Brake Lining Wear Dust File 456 I am enclosing three envelopes of the following cars containing dust removed from the brakes Car Comet Newport Chevrolet Lining 2308 1618 Inlite equipment Mileage 1266 miles 540 miles 9900 miles You will find that the dust consists partly of ferrous particles presumably abrasion products from the cast iron brake drums The remainder should be predominantly abrasion products from the brake lining themselves We can supply information on the composition of the brake linings used in the first two cars The thi car r wd as equipped with competitive lining a composition not known to us but undoubtedly containing asbestos fiber - ; : a H. G. Me^/n General Headquarters April 21 1967 F. L. Pundsack - Finderne Brake Lining Wear Dust Your Letter of 3/14 to F. J. Solon 4 Your File 259 Confirming our I approve your phone conversation of this morning recommendation that we collaborate with the U. S. Public information from Health Service this study through the release of The publication of our data under their certainly carry considerable weight auspices will It was certainly of considerable interest in a recent discussion with Dr. L. J. Cralley to learn that their findings parallel ours very closely The photographs attached which you requested be returned are H. M. Jackson COPY Research November and 27 Engineering 1963 Center File 456 Dr. K. W. Smith ~ GH Brake Lining Wear Dust I am enclosing three envelopes containing the brakes of the following cars dust Car - Lining . Mileage removed ; from . Comet 2308. 1266 miles Newport . 1618 , 540 miles Chevrolet : Inlite equipment 9900 miles : | You will find that the dust consists partly of ferrous particles presumably abrasion products from the cast iron brake drums i The remainder should be predominantly abrasion products from the brake lining themselves We can supply information on the composition of the brake linings used in the first | two cars The third car was equipped with competitive lining a composition not known to us but undoubtedly containing asbestos fiber . GK coi: W. * C. tle, E. Streib L. Meserve H. G. Koch . ; Heat 3 4 ae ote eee ae RN amg ys te COPY GHQ December 2 1963 W. C. Streib Research Brake Lining Wear Dust You have received a copy of H. G. Koch's letter to me of November 27 1963 on this subject I am forwarding the three envelopes containing the dust to you for analysis As discussed on my recent visit I wonder if you could have this dust analyzed to see if there are any free and recognizable asbestos fibers in it If there is any dust left over could you please retain it for I might like to have it used by our research pathologist at the Industrial Hygiene Foundation in Pittsburgh I shall be very pleased to visit you again at the Center to discuss the results of your tests when obtained CC CC H. G. Koch Research Kenneth W. Smith M.D. aaa MANVILLE RESEARCH AND ENGINEERING CENTER Report No. 456 Date January 20 1964 Title PETROGRAPHIC AND RAY Requested by W. C. Streib DIFFRACTION ANALYSES OF BRAKE LINING WEAR oe - Request No. 345 DUSTS SUMMARY Three samples of brake lining wear dust were examined petrographically to determine whether chrysotile fiber can be distinguished in this type of material Two of the samples were also examined by ray from the following brake linings diffraction for confirmation The samples were 1 1963 Comet republicaton 2 1963 Pontiac 3 Chevrolet 6 Inlite Lining or Petrographic examination showed the following distrbution The dust from the Comet lining contained an organic binder plus small percentages of quartz magnetite carbonates talc and rarely a few chrysotile fibers Chrysotile in sizes recognizable under the microscope constituted less than one general per cent of the total for The dust from the Pontiac lining appeared similar to the one from the Comet lining Not showing the same chrysotile fiber components in comparable amounts could be detected after prolonged Only an occasional bundle of examination of several slides The Chevrolet brake lining dust differs somewhat from the others in that it contains CONFIDETAL possibly 10 per cent quartz Talc appears to be absent appears to be present but was not positively identified of chrysotile fiber was noted as in Samples 1 and 2 A small amount An occasional of graphite small bundle ray diffraction results JM quartz weak pattern from Lining Dust from Comet Lining chrysotile talc trace trace magnetite trace Dust from Inlite Lining of Chevrolet quartz quartz magnetite major trace The trace of chrysotile detected by ray diffraction in the Comet lining dust could possibly amount to as much as 5 per cent of the total This would indicate that in addition to the occasional fibers seen microscopically there may be some Notebook No. 2910 p 52 2864 p 88 File 456 MANVILLE RESEARCH AND ENGINEERING CENTER Report No. 456 Summary Page 2 finely divided and possibly coated fibrils not recognized under the light micro- scope Failure of ray diffraction to detect any chrysotile in the Chevrolet lining dust sets the chrysotile content of this sample as well below 5 per cent The Pontiac lining sample was not examined by ray diffraction but the incidence of microscopically recognizable chrysotile in this sample is of the same order as in the Comet sample Contents Summary only Approved by L. dsak F. L. Pundsack Reported by Bailey D.D. Bailey Bailey republicaton ray Diffraction by or distrbuion eh K. W. Smith GH general for Not C. F. Rassweiler A. C. Smith 3 F. L. Pundsack W. C. Streib H. G. Koch D. Bailey J. P. McGourty Library 2 GH CONFIDETAL JM APPENDIX I meer Fage awe a 11 Figure 5 1 micron Electron Micrograph of Phase II Box and Drum Mag 30,000x Brake Lining Composite Wear Dust EMS 620A AND ENGINEERING CENTER Page republicaton or distrbution general for Not CONFIDETAL JM Figure 7 1 micron Electron Micrograph Brake Lining Phase III Drum and Box Composite Mag 30,000X Wear Dust EMS 622A MANVILLE RESEARCH AND ENGINEERING CENTER Report No. Page 456-1-94 12 republicaton or distrbution general for Not CONFIDETAL JM Figure 6 Electron Micrograph Phase III Sample 1 Mag . 3300,00,0X 000X 1 micron Brake Lining Wear Dust EMS 621A republication distribution distrbuion general for Not CONFIDETAL JM MANVILLE RESEARCH AND ENGINEERING CENTER Title STUDY OF WEAR Project 2550 DUST FROM BRAKE LINING Report No. 456-2506 Date December 19 1966 SUMMARY Brake lining wear dust was collected on a membrane filter mounted in a box which surrounded a brake run on an inertia dynamometer In addition to this airborne fraction the dust that settled to the floor of the box and that which remained within the brake was also collected A total of 6-1 grams of dust was collected from 2150 stops during a total time of about 110 hours The airborne portion was 2.7 grams Most of the stops were made from 35 miles per hour at 10 secdeceleration interspersed with stops from 50 mph about 10 per cent The airborne dust was examined by light microscope electron microscope rays and other means Asbestos fiber could be detected only by the electron microscope which gave a maximum of 1.4 per cent fiber by weight in the wear dust although the lining contains 70 per cent chrysotile fiber This result is accounted for by the high surface temperature and severe abrasion during even the mild braking of these tests when the average temperature did not exceed 200 Calculations show that the surface temperature at the true area of contact 1 per cent of the apparent area can reach 2000 or more It is concluded that most of the fiber is converted to an amorphous mineral by intense heat and fine grinding It is recommended that samples of the particulate matter in the atmosphere be i collected at suitable distances from highways and the sample examined in the electron microscope for asbestos Contents Summary Introduction culations Appendix II Tables 1 Appendix IV References Experimental Method and 2 Appendix III Results , I FiguresAppen,diaxnd cal- ae CC F. J. Solon GH - K. W. Smith MD -GH -GH Reported by David Sinclair Basic Physics Section A. C. Smith S F. L. Pundsack Att S. J. Dec Speil H. G. Koch W. C. Streib H. W. Gilbert H. F. Remde D. Sinclair Library 2 Notebook 723 p 141 File 456 MANVILLE RESEARCH AND ENGINEERING CENTER No. Report Page 1 454566--22550066 INTRODUCTION Laboratory measurements were made to determine what type of particulate matter and gases are given off when a brake lining is worn during operation The wear of the drum usually cast iron is necessarily included Of special interest is the airborne dust expelled into the atmosphere from the moving brake Previously some observations had been made at Manville Research and Engineering Center on dust removed by hand from a laboratory brake but this is the first time to our knowledge that any observations have been made on the airborne fraction A search although of the literature revealed no the rate of wear is sometimes measurements on brake lining wear dust given Recently numerous articles 4,5 have appeared calling attention to the widespread use of asbestos in materials such as brake linings floor tile roofing asbestos products is usually assumed that as these materials wear much of the asbestos etc. fiber It is dispersed into the atmosphere thereby contributing to air pollution and creating a health hazard This is understandable since the asbestos content of these materials is often high 70 per cent in the brake linings used in these tests and asbestos is commonly considered to be indestructible However we know of no in measurements made to urban atmospheres test this assumption or to observe the amount of asbestos ; distribution The present tests show that during the wear of brake linings very little asbestos fiber is dispersed into the atmosphere Examination of the airborne dust by distribution light microscope electron microscope and ray diffraction showed very little general of the verted original chrysotile fiber to an amorphous mineral by Nearly all the fiber appears to have been conthe severe abrasion and intense heat generated for during brake operation A point made on eight electron micrographs gave an Not upper limit of 1.4 per cent fiber in the airborne dust This is not surprising when one calculates the amount of energy dissipated while operating a passenger car brake It is shown in the appendix that the heat generated CONFIDETAL raises the temperature of the surface of contact between brake lining and drum to about 2400 This high temperature occurs on the surface of the lining at the regions of actual contact with the drum much less than the apparent area of contact.6 These regions of contact are worn away during rubbing so that the actual contact continually shifts to new regions As a result the wear particles of asbestos JM Tabor resin etc. are heated to a very observed many incandescent high temperature hot spots during for the a very short time Bowden and rubbing of metals on glass EXPERIMENTAL METHOD A wooden box approximately a 1-1 cube with a Lucite top was constructed to fit around a 1961 Ford brake mounted on the C inertia machine in the Friction Materials Research Section pilot plant Figure 1 is a photograph of the box mounted on the brake The left rear side has a conical air inlet which carries a square Flanders fiber glass filteor n the entrance into the box The right front side and tapers of the box to a square opening at the outlet carries two 8 x in filter holders for Gelman membrane filters These holders are connected through flexible hoses to a 7-1 industrial vacuum cleaner not shown When the vacuum cleaner was run about 150 cfm of free air was drawn through the Flanders filter over the brake and out through the membrane filters to collect the airborne wear dust The pressure drop across the membrane filters was about cm Hg measured with the mercury manometer shown standing on the box at the right connected to a petcock on the exit side of the filters The pressure drop across the Flanders filter was about in H2O measured with the water manometer shown on the left connected to a tube through the side of the box MANVILLE RESEARCH AND ENGINEERING CENTER Report No. Page 2 456-2506 Since the interior of was necessary to seal the the box was under a negative pressure of in H joints and screw holes against entrance of dusty Oit ambient air This was done on the outside with DUXSEAL and on the inside with contact adhesive The interior of the box and the parts of the brake and mounting within the box were painted white to show up any wear particles that settled out The stationary hubs at each end of the brake drive were sealed to the ends of the box with in rubber sheet and rubber cement Figure 2 shows the auxiliary equipment used to measure the relative rate of evolution of wear dust during and after braking At the left rear is seen a Sinclair aerosol photometer connected to the side of the box through a petcock In the left foreground is a logarithmic amplifier connected to a Varian recorder on the right Dusty air was drawn continuously from within the box and through the photometer at a rate of about 1 cfm by means of a hp Gast pump Since this rate of air removal is about 0.7 per cent of the total air flow its reduction of the amount of dust collected on the membrane filters is negligible republication Figure 3 at 10 to shows the type of record obtained during stops from 35 12 secdeceleration at intervals of 2-1 minutes and 50 miles per hour Two of the stops were or from 50 mph as indicated and the others from 35 mph Usually a more or less regular pattern occurred in which the dust concentration fell to near zero between each of several stops and then remained at an intermediate level for a couple of stops distribution distribution distrbuion The marks numbered 2 3 and 4 are calibration points for the logarithmic amplifier They are obtained by interposing neutral optical filters of known light transmission general into the photometer light beam for Figure 4 is the resultant calibration curve which shows the approximate logarithmic Not relationship between chart reading and dust concentration the latter proportional to scattered light intensity For example a chart reading of 50 corresponds to a dust concentration about 100 times that for a reading of 5 CONFIDETAL Dust was collected during 2150 stops most of it on two membrane filters The average temperature of the brake lining was kept at 175-200 and was measured with a thermo- couple set in a hole in the lining about 1/16 in below the surface The temperature was kept low in order to simulate average braking by increasing the time between stops to 3 to 4 minutes when overheating commenced As indicated earlier this tempera- JM ture is far below the instantaneous surface temperature see Appendix I RESULTS Three fractions of wear dust were collected 1. Airborne dust collected on membrane filters 2.71 gm 2 Dust removed from within brake after completion of test 3.54 gm 3. Dust collected from within box after completion of test 0.214 gm These fractions all include some cast iron worn from the drum about 1 gm total The samples were analyzed for ignition loss by light and electron microscope ray spectrometer emission spectrograph infra spectrograph size analyzer In addition air samples were withdrawn from and the Coulter particle box during braking and analyzed by the Gollob Analytical Service Table 1 shows the results obtained MANVILLE RESEARCH AND ENGINEERING CENTER Report Page 3 4564-255606-2506 Table 2 shows the composition of linings used is about 70 per cent chrysotile fiber after the It is water seen that and other the finished lining volatiles are driven off The total weight of sample collected 6.46 gm is much less than the measured weight loss of the brake shoes and drum primary 4.0 1 gm secondary 7.0 1 and 2 1 gm However the accuracy of these weights is questionable because of the heaviness of the shoes and the drum We feel certain that negligible loss of dust occurred during the tests so that we cannot account for the discrepancy republication general for Not CONFIDETAL JM MANVILLE RESEARCH AND ENGINEERING CENTER Report Page 4 4564562506 2506 APPENDIX I Calculation of surface temperature of lining These tests simulate a front wheel brake of a 1961 Ford designed to decelerate 30.5 per cent of the car mass or 1270 pounds At a velocity the kinetic energy of this mass is 106,000 ft or 136 Btu of At 50 mph = 73.5 sec a deceleration of 10 secthis heat is generated during a stop of 7.35 seconds duration During the first second the average rate of heat generation is 34.6 Btu per second = 8.72 x 103 sec This heat is generated over a total lining area of 52.5 sq in 21 x 2-1 rubbing against cast iron Bowden and Tabor--- give a method which allows a calculation of the true area of contact Their experiments on metals showed that the actual area of contact is directly pro- portional to the load As the load was increased the points of contact flowed plastically until the area of contact was sufficient to support the load In the case of less ductile materials such as brake linings the points of contact would republicaton be crushed until the bearing was no longer exceeded area was large enough so that the crushing strength or For metals Bowden and Tabor found that the yield pressure is three times the tensile strength We make the same assumption for brake linings Manville Research re- distrbuion port 456 received from A. J. Taylor gives a tensile strength of 1590 psi for a lining 6.87 x similar to that 105 sq ft used in these tests The yield pressure is then Pm = 4770 psi = . general According to the definition of the yield pressure = Pm L where L is the load and for is the real area of contact The load on the lining may be calculated by equating Not the torques about the axle of the simulated car The torque on the tires is mdR = 1270 x 10 x 1.09 CONFIDETAL Here m = mass declerated = 30.5 per cent of total mass of car = 1270 mass d = deceleration = 10 sec= 32.2 JM R rolling radius = 1.09 ft The torque on the brake lining is Meir = 0.4 x L x 0.463 Here = coefficient of friction = 0.4 L = load r drum radius = 0.463 ft Equating these two torques gives the load L = 2320 force en The roughness of even the smoothest brake lining microinch average is about 2500 times molecular dimensions MANVILLE RESEARCH AND ENGINEERING CENTER Report Page 5 456-2506 The real area of contact is given by the ratio of the load to the yield pressure = Pm = 2320/4770 - 0.487 sq in Since the apparent area 0.93 per cent The per the applied pressure to of contact A = 52.3 cent real contact is the yield pressure sq in the per cent real contact is alternatively given by the ratio of The equation used to calculate the temperature is given by Carslaw and Jaeger 10 The maximum temperature of a strip the lining sliding over a infinite medium the drum is given by 221 221 T = max qq Ked 3 2 republication = q 2.78 x 10 sec cm = rate of heat generation per sq cm of real contact area 1 = 26.8 cm = 1/2 length of lining or K == 0.111 cal = thermal conductivity of drum distribution distrbution general for Not c = 0.1189 cal = specific heat of drum d = 7.5 cm= density of drum = 888 sec = average rubbing velocity of lining over drum during first second These at 10 values give Tmax = 2440 secdecleration near the beginning of a stop from 50 miles per hour CONFIDETAL For a stop from 35 mph the maximum temperature would be about 2000 JM The equation is derived for a moving heat source lining is 84th that of the drum the lining may Since the be treated conductivity of the as a heat source J.M.CONFIDENTIAL Not for general distribution or republication TABLE 2. APPENDIX II Report 456-2506 Page T BRAKE LINING COMPOSITION SC solvent gas Polyrez 2231 cashew resin 3M Company NC 320 cashew resin Water ---- -- Carbon Black Coal Whiting Iron Oxide Hycar 1411 Red Mapico Barytes Luminite Cement 7M06 Fiber Primary shoe PC 3504 2.06 4.12 4.74 7.62 ; 3.09 0.62 -- 5.16 3.51 i 1.03 0.82 2.78 0.52 63.93 100.00 Secondary shoe PC 3442 1.5 5.0 5.2 8.4 2.5 0.6 0.8 11.0 3.5 0.5 1.0 - - 60.0 100.00 mac 11/4/66 mas 1 [ - | Kirbcime 13.5 2.71 m no fibr classy or browm agglomerates Musson microscope Ached csbay Ached Doiepesrd Spectrograph spectricrapa spectricrapa Ashad As collected Couldn Couldn cou be i few fibers *** * * no chrysotile chrysotile M 31 7 see photos identified 102 31 no sotile identified otteghed Iron Fe03 19 | Phenolics CaO 11203 " Ba Trace medien diams Number 2.75 microns Mass 4.75 microns enali - Pure Air 22 | Within brake 3.5470 3.5470 19.5 | no fiber glassy or browm agglomerates F analysis no chrysotile | 0 31 incomplete | identified identified Sing 316 Iroh F-- 203 105 Cao in A1203 2 A1203 -- -- Trace Peoee oes 3 Within box 31.0 | no fiber glassy for 0.214 74 brow agglomerates contaminated analysis mo a=sottte | Mgo _31 incomplata | iss-pipiea Ten Sing 31 Feg0z | 100 Cao Boa 412|023 Ba Trace Paint bperver - S. Wegrzyn D. Bailey D. Bailey ry tory 1. Sutherland S. A Euras ( This very small fraction ' contaminated with paint wool etc. from box in water Dilute suspension in WariWnarigng blender for 1 mince _ *** more than 1.4 per cent by weight 4 -| Service j general distribution or republication DLE 1 DRAR DUST Report 450-6700 Page 6 Lice microstone microstone 7 microstone +] Ashed 3007 i af Airborne 2.71 om 13.5 | no fiber glassy or brow agglomerates Electron microscope microscope Asbed ray 2 spectrometer Emission ' spectrograph Ashed Ashed spectrograpspechtrograph spectrograph As collected Coulter Coulter counter counter Blended few fibers *** no chrysotile | 31 7 see photos identified 102 31 Iron F-- 203 19 CaO A no chrysotile | median diams identified Number 2.75 microns Phenolics Mass 4.75 microns A1203 | 25 Ba Trace C42 analisis analisis Pure Air 2 | Within brake 3.54 cm 19.5 | no fiber glassy or brown a agglomerates r analysis no chrysotile | Mgo| 31 incomplete | identified 102 31 Iron 203 | 19 Cao 204 A1202 % s Ba Trace nonnfene ee _ 3 Within 31.0 no fibdr _box glassy or 0.214 gm brown agglomerates ag lomerates contaminated analysis incomplate incomplate no chrysotile identified Ixch MgO 31 102 31 Fe203 | 19 Cao C AL203 % Trace Paint Saa2f-=>> Saki aedntod S. Wegrzyn D. Hailey D. Bailey 2. Nafourty A. Sutherland S. Wegrzyn A. Burns : : us ! This very small fraction contaminated with paint wood etc. from box 1 Dilute suspension in water beaten in Waring blender for i 1 minute _. No*** t more than 1.4 per cent by weiweigghtht EL} Collos Analytical ServiceService MANVILLE RESEARCH AND ENGINEERING CENTER APPENDIX III Report No. 456-2506 Page 8 Figure 1 for Not CONFIDETAL M. J. Figure 2 MANVILLE RESEARCH AND ENGINEERING CENTER APPENDIX III Figure 3 Report No. Page 456-2506 100 | an | i L, ei republication or } distrbuiondistribution distribution | {I UY HPA general Apres Holedah TEOTU it | Not ALAT E eed . abr Tine FREE i it | sda EE DEL by |} CONFIDETAL saQ0 ETE a Lyset roeri wih M. t sutn J. S0lys790 I wil ' HH t IITbeathee | {; Ht | t niaLdabeseab i Ne eT | aia nity eli me itl tit | ain +4 | min f : 44 i H ti: ai 1 i awe he . Pred | atHe 100 TEREAUOGHH We De EDTOETEN | | 108 TOOEA BONE 70DIST TANCETS Peter filinaliFTVEONgT ety YT! fel 7 we - APENDIX AP ENDIX be . general J.M.CONPT J.M.CONPT J.M.CONPT J.M.CONPT distribution distribution distribution 4 - 100.00 100.00 100.00 100.00 100.00 [t SINCLAIR SINCLAIR PHOENIX CALIBRATION PHOENIX PHOTMETR PHOTOMETER CALIBRATION SINCLAIR SINCLAIR SINCLAIR SINCLAIR SINCLAIR SINCLAIR LIBRATION PHOENIX PHOENIX CALIBRATION CALIBRATION CURVCEURVE PHOTOMETERPHOTOMETER PHOTOMETER PHOTOMETER PHOTOMETER PHOTOMETER SRE U.10 U.10 9 i V.01 V.01 V.01 t 4 0.00 0.00 0.00 lo > st QU QU ve) 100 100 100 Chart Reading Reading MANVILLE RESEARCH AND ENGINEERING CENTER Report Page 11 456-2506 APPENDIX IV References 1. Research report 456 January 20 1964 Petrographic and ray Diffraction Analyses of Brake Lining Wear Dusts D. Bailey J. P. McGourty 2 Mechanical Design and Systems Handbook Chap 28 p 43 D. Sinclair McGrawHill 1964 The Fundamentals of Asbestos Friction Materials R. T. Halstead Paper Trade J. 118 p 30-33 March 2 1944 Biological Effects of Asbestos p 196 J. G. Thomson N.Y. Academy of Sciences republicaton December 31 1965 5 Chem Week September 10 1966 or The Friction and Lubrication of Solids Vol 1 F. P. Bowden and D. Tabor Oxford distrbuion Clarendon Press 1950 Report 456 December 8 1966 Brake Lining Wear Dust - Evaluation by general Light Electron Microscopy D. Bailey for Memorandum report No. JM December 9 1966 Not Memorandum report No. October 21 1966 Conduction of Heat in Solids 2nd Ed p 269 H.S. Carslaw and J. C. Jaeger CONFIDETAL Oxford Clarendon Press 1959 JM Research March 1 & Engineering 1967 Center STUDY OF WEAR DUST FROM BRAKE LINING Excerpted from Dr. David Sinclair's Report 456-2506 Summary Brake lining wear dust was collected on a membrane filter mounted in a box which surrounded a brake run on an inertia dynamometer In addition to this airborne fraction the dust that settled to the floor of the box and that which remained within the brake was also collected A total of 6-1 grams of dust was collected from 2200 stops during a total 2.7 grams Of the stops 2150 time were of about 110 made from 35 hr mph The airborne portion was at about 12 secdecelera- tion interspersed with which were 50 stops from 50 mph The brake operating conditions were selected to give heavy wear of the linings without causing abnormally high temperatures and would correspond roughly to that of heavy stop and start traffic on a highway with a 50 mph speed limit The airborne dust was examined by light microscope electron microscope rays and other means Asbestos fiber could be detected only by the electron micro- scope which gave a maximum of 1.4 per cent fiber by weight in the wear dust although the lining contains 70 per cent chrysotile fiber This result is accounted for by the high surface temperature and severe abrasion during these tests when the thermocouple temperatures before brake application were held to 200F maximum and the peak temperatures indicated by the thermo- couple in the lining probably never exceeded 300F Calculations show that the surface temperature at the true area can reach 2000C or more area of contact It is concluded 1 per cent of the apparent that most of the fiber is con- verted to an amorphous mineral by intense heat and fine grinding Introduction Laboratory measurements were made to determine what type of particulate matter and gases are given off when a brake lining is worn during operation The wear of the drum usually cast iron is necessarily included Of special interest is the airborne dust expelled into the atmosphere from the moving brake A search of the literature revealed no although the rate of wear is sometimes have appeared calling attention to the measurements on brake given 2 Recently lining wear dust numerous articles 4 widespread use of asbestos in brake linings STUDY OF WEAR DUST FROM BRAKE LININGS -2- March 1 1967 Although it has been assumed in some instances that much of the asbestos fiber is dispersed into the atmosphere we know of no measurements made to test this assumption or to observe the amount of asbestos in urban atmospheres The present tests show that during the wear of brake linings very little asbestos fiber is dispersed into the atmosphere Examination of the airborne dust by light microscope electron microscope and ray diffraction showed very little of the original chrysotile fiber Nearly all the fiber appears to have been converted to an amorphous mineral by the severe abrasion and intense heat generated during brake operation A count made on eight electron micrographs gave an upper limit of 1.4 per cent fibrous material in the airborne dust Most of this fibrous material cannot be positively identified as being either chrysotile or a degradation product thereof because of its fine size This is not surprising when one calculates the amount of energy dissipated while operating a passenger car brake It is shown in the Appendix that the heat generated could theoretically raise the temperature of the surface of contact between brake lining and drum to about 2400C assuming no melting The high temperature typically occurs on the surface of the lining at the region of actual contact with the drum This actual area of contact is much less than the apparent area of contact.5 These regions of contact are worn away during rubbing so that the actual contact continually shifts to new regions As a result the wear particles of asbestos resin etc. very short time Bowden and Tabor5 the rubbing of metals on glass are heated to observed many a very high temperature for a incandescent hot spots during Experimental Method A wooden box approximately a 1-1 cube fit around a 1961 Ford brake mounted on the with a Lucite top was constructed C inertia machine in the Friction to Materials Research Section mounted on the brake The pilot plant Figure left rear side has a 1 is a photograph conical air inlet of the box which carries a ft square Flanders fiber glass filter on the entrance and tapers to a in square opening at the outlet into the box The right front side of the box carries two 8 x 10 filter holders for Gelman membrane filters These holders are connected not shown through flexible hoses to a When the vacuum cleaner was 7-1 hp industrial vacuum cleaner run about 150 cfm of free air was drawn through the Flanders filter over the brake and out through the membrane filters to collect the airborne wear dust The pressure drop across the membrane filters was about cm Hg measured with the mercury manometer shown standing on the box at the right connected to a petcock on filter was the exit side about in of the filters The pressure drop across the . Flanders H20 measured with the water manometer shown on the left connected to a tube through the side of the box Since the interior of the box was under necessary to seal the air This was done on joints and screw the outside with a negative pressure of in H20 it was holes against entrance of dusty ambient DUXSEAL and on the inside with contact adhesive The interior of the box were painted white the box and the parts of the brake to show up any wear particles that and mounting settled out within The stationary hubs at each end of the brake drive were sealed to the ends of the box with 16 rubber sheet and rubber cement STUDY OF WEAR DUST FROM BRAKE LININGS -3- March 1 1967 Figure 2 shows the auxiliary equipment used to measure the relative rate of evo- lution of wear dust during and after braking At the left rear is seen a Sinclair aerosol photometer connected to the side of the box through a petcock In the left foreground is a logarithmic amplifier connected to a Varian recorder on the right Dusty air was drawn continuously from within the box and through the photometer at a rate of about 1 cfm by means of a hp Gast pump Since this rate of air removal is about 0.7 per cent of the total air flow its reduction of the amount of dust collected on the membrane filters is negligible Figure 3 10 to 12 shows the type of record obtained secdeceleration at intervals during stops from of 2-1 minutes 35 and 50 mph at Two of the stops were from 50 mph as indicated and the others from 35 mph Usually a more or less regular pattern occurred in which the dust concentration fell to near aero between each of several stops and then remained at an intermediate level for a couple of stops The marks numbered 2 3 and 4 are calibration points for the logarithmic ampli- fier They are obtained by interposing neutral optical filters of known light transmission into the photometer light beam Figure 4 is the resultant calibration curve which shows the approximate logarithmic relationship between chart reading and dust concentration the latter proportional to to scattered light intensity For example a chart reading of 50 corresponds a dust concentration about 100 times that for a reading of 5 Dust was collected during 2200 stops most of it on two membrane filters The temperature of the brake lining surface was measured by a thermocouple set in a hole in the lining approximately 16 below the surface The cooling interval between brake applications was adjusted so that this thermocouple indicated a temperature in the range between 175 to 200F just before brake application This was done in order to simulate average braking As indicated earlier this temperature is far below the instantaneous surface temperature see Appendix I Two typical electron micrographs are shown in the Appendix Results Three fractions of wear dust were collected 1. Airborne dust collected on membrane filters 2.71 gm 2. Dust removed from within brake after completion of test 3.54 gm 3. Dust collected from within box after completion of test 0.214 g These fractions all include some cast iron worn from the drum about 1 gm total The samples were analyzed for ignition loss by light and electron microscope ray spectrometer emission spectrograph infra spectrograph and Coulter STUDY OF WEAR DUST FROM BRAKE LININGS -4- March 1 1967 particle size analyzer In during braking and analyzed the results obtained addition air by the Gollob samples were withdrawn from the box Analytical Service Table 1 shows The brake lining chrysotile fiber utilized in these experiments with a cashew resin binder contained approximately 70 per cent STUDY OF WEAR DUST FROM BRAKE LININGS -5- March 1 1967 APPENDIX I Calculation of surface temperature of lining These tests simulate a front wheel brake of a 1961 Ford designed to decelerate 30.5 per cent of the car mass or 1270 lb. the kinetic energy of this mass is 106,000 At velocity of lb or 136 Btu 50 mph = 73.5 sec At a deceleration of 10 secthis heat is generated during a stop of 7.35 seconds duration During the first second the average rate of heat generation is 8.72 x 103 cal This heat is generated over a total lining in 21 x 2-1 rubbing against cast iron 34.6 area Btu of 52.5 = sq Bowden and Tabor give a method which allows a calculation of the true area of contact Their experiments on metals showed that the actual area of contact is directly proportional to the load As the load was increased the points of contact flowed plastically until the area of contact was the load In the case of less ductile materials such as sufficient to support brake linings the points of contact would be crushed until the bearing so that the crushing strength was no longer exceeded area was large enough For metals Bowden and Tabor found that the yield pressure is three times the ; tensile strength We make the same assumption for brake linings Manville Research Report 456 received from A. J. Taylor gives a tensile strength of 1590 psi for a lining similar to that used in these tests The yield pres- sure is then = pm 4770 psi = 6.87 x 105 sq ft According to and a is the equating the the definition of the yield pressure Pm = a where L is the load real area of contact The load on the lining may be calculated by torques about the axle of the simulated car The torque on the tires is mdR = 1270 x 10 x 1.09 = Here m mass decelerated = 30.5 per cent of total mass of car = 1270 mass d = deceleration = 10 sec= 32.2 R = rolling radius = 1.09 ft The torque on the brake lining is Lr = 0.4 x L x 0.463 Here = coefficient of friction = 0.4 L = load r = drum radius = 0.463 ft The 2500 roughness of even the smoothest times molecular dimensions brake lining microinch average is about STUDY OF WEAR DUST FROM BRAKE LININGS -6- March 1 1967 Equating these two torques gives the load L = 2320 force The real area of contact is given by the ratio of the load to the yield pressure a == Pm = 2320/4770 = 0.487 sq in Since the apparent area of is 0.93 per cent The per of the applied pressure to contact A = 52.3 cent real contact sq is the yield pressure in the per cent real alternatively given by contact the ratio The The Jaeger--- equation used to calculate the temperature is given by Carslaw and maximum temperature of a strip the lining sliding over a infinite medium the drum is given by 2 21 v Kod = q 2.78 real x 103 cal contact area cm = rate of heat generation per sq cm of 1 = 26.8 cm = 1/2 length of lining K = 0.111 cm.sec C = thermal conductivity of drum c = 0.1189 cal C = specific heat of drum = 7.5 cm= density of drum 888 sec = average first second rubbing velocity of lining over drum during These values give Tmax = 2440C near the beginning of a stop from 50 mph at 10 sec deceleration For a stop from 35 mph the maximum temperature would be about 2000C The equation the lining is source is derived from a moving 84th that of the drum heat source Since the conductivity the lining may be treated as a heat of STUDY OF WEAR DUST FROM BRAKE LININGS APPENDIX II Table 1. Analysis of Brake Lining and Drum Wear Dust March 1 1967 + : {o.] Airborne 13.5 no fiber i 2.71 ga glassy or brown agglomerates Electron 7 microscope microscope Ached ray & spectrometer ished mission Infra q spectrograph spectrograph spectrograph Ashed As collected __-5 shh analinis analinis Pure Air few fibers *** no chrysotile | MgO 31 see photos |_ identified S102 31 : = Iron Fe03 19 CaO 34 A1203 % no chrysotile identified median median . diams NumberNumber 2.75 microns Mass .75 microns Ba Trace 2 Within 19.5 no fiber brake 3.54 m glassy or brown aglomerates agglomerates i ( analysis no cervsotile | Med 31 incomplete | identified : Irch < |fl31 F-- 203| 195 CaO L A1203 A1203 | % Ba Trace ote Seed were noma 2 | Within box 31.0 | no fiber glassy or 0.214 om brown agglomerates contaminated contaminated analysis no wortgottta | Mad 31 incomplete incomplete | dified S102 319 Esch F2203 / 199 CaO 2h. A1203 % Ba Trace | Paint wwen-den-- | ee : q 5) McGourty S. Wegrzyn D. Bailey D. Bailey J. A. Sutherland S. Wegrzyn a Puros 4 i j small fraction was contaminated with caint wock etc. from box Dilute suspension in water beaten in Waring Blendor for minute( jot more than 1 per cent by weight Colle's Analytical Service STUDY OF WEAR DUST FROM BRAKE LININGS -8- APPENDIX III March 1 Lee Figure 1 Figure 2 STUDY STUDY STUDY STUDY OF WEAR DUST FROM BRAKE LININGS APPENDIX III Figure 3 Marci Marci STUDY STUDY BRAKE OF WEAR LININGS DUST FROM Win ee 1d N CALIBRATION SINCLAIR CURVE PHOTOMETER -10- 7 a Cae Concentration it Lip i 1.00 1.001.00 TtyeConcetraion pope pes Intesity Chart Reading STUDY OF WEAR DUST FROM BRAKE LINING -13- APPENDIX V References March 1 1967 Mechanical Design and McGraw 1964 Systems Handbook Chap 28 p 43 D. Sinclair The Fundamentals of Asbestos Friction Materials R. T. Halstead Paper Trade J. 118 p 30-33 March 2 1944 Biological Effects of Asbestos p 196 J. G. Thomson N. Y. Academy of Sciences December 31 1965 Chem Week September 10 1966 The Friction and Lubrication of Solids Vol 1 F. P. Bowden and D. Tabor Oxford Clarendon Press 1950 Conduction of Heat in Solids 2nd Ed p 269 H. S. Carslaw and J. C. Jaeger Oxford Clarendon Press 1959 Report 456 December 8 1966 Brake Lining Wear Dust - Evaluation by Light and Electron Microscopy D. Bailey Memorandum report No. JM December 9 1966 Memorandum report No. 124 October 21 1966 Table 1. Analysis of Brake Lining and Drum Wear Dust March 1 1967 . Trfvg ered Coul ten Ode ! 7 microscope i microscope spectra cour analitis | Ached ished Ashed As collected Blended : Pure ir . 13.5 | no fiber few fibers *** no chrysotile | Mgo 31 no chrysotile median dians glassy or see photos | identified 102 31 identified Number 2.75 cicrons browm agglomerates agglomerates _ Iron F2203 19 CaO a Mass 75 microns A1203 | 25 -- -- Trace 2 | Within brake 3.54 oo 19.55 _ | no fiber glassy or brown agglomerates -- analysis no chasotile | Ngo 315 incomplete | identified 102 315 Irch F9203 | 195 Cao im A1203 A1203 | % Ba Trace Within bo 31.05 | no fiber glassy or 0.214 31 brown agglomerates contaminated analysis no chrisotila chrisotila | MgQ 31 incomplete | fdemnified fdemnified Tich 102 | 31 Feglz | 19 CaO 3g 03 | % Trace Paint T Wegrzyn D. Bailey D. Bailey J. McCourty A. Sutherland Wegrzyn Burns i a was from bes i This very small fraction " contaminated with taint wook etc. Dilute suspension in water beaten in Waring Blendor for 1 minute __ *** more than 1.4 per cent by weight Called Analytical Servide MANVILLE RESEARCH AND ENGINEERING CENTER Report No. Date 456 June 13 1968 Title WEAR PRODUCTS FROM BRAKE LINING - Nature EIS EE Requested by H. G. Koch 381 of the Material SUMMARY Airborne brake lining wear dust was collected on a Gelman filter membrane mounted in an air tight enclosure box The enclosure contained a brake assembly which was connected to an inertia dynamometer Wear dust was collected at three different temperatures phases The average temperature of Phase I was 175F Phase II 330F and Phase III 550F simulating various traffic conditions In addition wear dust was collected from the brake assembly and the inner surfaces of the sealed box In Phase I a series of sets of stops were made The airborne dust was collected at the end of each set of stops Only one set of stops was made in Phases II and III republicaton A material balance study was made between the weight loss of the brake shoes and drum or and the amount of dust collected from the three sources The airborne portion was approximately 48 per cent of the total dust collected from a total of 2926 stops distrbuion This value is high because all dust samples were contaminated with iron and to a degree with stencil ink used to spray the inner walls of the box The source of iron is from the brake drum and from areas on the brake backing plate where lesser the appreciable metal wear was noted Analyses show that most of the contamination occurred general during Phase I. The actual amount of dust collected was about 30 per cent higher than for the weight loss of the brake shoes and drum because of the metal wear of the backing plate which is not weighed The amount of dust collected from Phases II and III was Not about 45 per cent of the weight loss of the brake shoes and drum This difference is partially attributed to the loss of water of crystallization of chrysotile and volatilization of organic material CONFIDETAL Chrysotile fiber was detected only by the electron microscope technique The maximum concentration of fiber in the airborne dust was found in Phase III to be 0.55 per cent On the drum and in the box composite the maximum fiber content was 0.65 per cent Phase I JM Due to the severe abrasion and heat generated in the braking operation the bulk of the fiber 70 per cent of the lining was converted to an amorphous silicate The amorphous silicate formed appreciable amounts of forsteirn iPhtasee that surface braking temperatures reached at least 600C III indicating The only organic constituent actually identified in the wear dust was cashew resin Additional smaller components were detected but not identified A phthalate plasticizer a contaminant from stencil ink was present in all samples examined Notebook No. 3656 pp 27-31 3613 p 125 3664 p 24 pp 80-81 3605 p 99 3612 File 456 211 MANVILLE RESEARCH AND ENGINEERING CENTER Report No. Page 456-7-94 2 This study is a continuation and expansion of the work begun by Dr. Report No. 456-2506 Sinclair See For details see Results of Analysis of this report and Memorandum M456-386 Contents Summary Materials Submitted and Methods of Analysis and Photomicrographs Appendix ) Results of Analysis Reported by 5. Analytical W. Wegrzyn Chemistry Section republicaton Ray Work by or distrbuion Spectrographic Work by J. Sutherland Analytical Chemistry Section general .. .. Bailey for Microscopic Work by Not D. A. Bailey Research Basic Chemistry Research Section CONFIDETAL al Chromatographic Work by HN Smith H. N. Smith Analytical Chemistry Section JM a cc H. M. Jackson - DH F. L. Pundsack 2 K. V. Lindell - Asb DH S. Speil J. Dec E. M. Fenner H. G. Koch H. F. Remde C. N. Thompson S. W. Wegrzyn Library 2 MANVILLE RESEARCH AND ENGINEERING CENTER Report No. 456 Page 1 MATERIALS SUBMITTED AND METHODS OF ANALYSIS Materials Submitted Laboratory Index No. A97-44-1 A97-44-1 Description Airborne dust Sample 2 Phase I A97-44-2 - Airborne dust Sample 6 Phase I A97-44-3 Composite dust from drum and box Phase I A97-44-4 A97-44-4 A97-44-4 Airborne dust Sample 1 Phase II A97-44-5 A97-44-5 Composite dust from drum and box Phase II A97-44-6 Airborne dust Sample 1 Phase III republicaton 897-44-7 Composite dust drum and box Phase III Only the above samples were analyzed and the drum and box samples were composited or Methods of Analysis distrbuion The amount of airborne after collection All dust was determined by weighing filter membrane other dust samples were collected by vacuum and before and weighed general The samples were submitted for the following analyses or examination spectrographic for ray infrared microscopic and gas chromatographic Not The amount of chrysotile fiber was determined by the point count method that has been used for determining the amount of fiber in water samples CONFIDETAL RESULTS OF ANALYSIS Material Balance JM Only in Phase I were work The remaining sets of dust collected at various phases had only one set of stops stops to duplicate previous The data for Phase I is as follows Run No. 123 2 3 4 2 Total Net Stops 6 136 167 139 439 oil leak 121426 59 Weight of dust from brake Weight of dust in box Total dust collected in assembly Phase I Grams of Airborne Dust Collected + 0.2520 0.3330 0.3330 0.2460 1.5036 1.5036 3.6067 5.9413 6.3930 2.9630 15.2973 grams MANVILLE RESEARCH AND ENGINEERING CENTER Report No. 456 Page 2 The following table contains data from the three phases Phase I Phase II Phase III Temperature Number of stops Total dust collected gms Airborne dust collected gms 175F 2146 15.2973 5.9413 330F 720 1.7256 1.3561 550F 60 8.7435 5.1218 Per cent airborne dust collected 38.8 78.6 58.6 Loss Loss Loss in weight in weight in weight of of of primary shoe gms secondary shoe gms drum shoe gms 2.805 8.390 0.605 0.855 2.210 0.880 5.420 12.370 0.976 Total loss in weight of brake assembly 11.800 republicaton total dust collected X 100 or weight loss of assembly 129.6 Totals distrbuion Airborne dust All dust general Per cent airborne dust Loss in weight of brake for assembly Not 12.4192 25.7664 25.7664 48.2 34.511 total dust collected X 100 weight loss of assembly 74.6 3.945 43.7 18.766 46.6 CONFIDETAL It is obvious that Phase I is heavily contaminated About 30 per cent more total dust was collected than the weight loss of the brake shoe and drum The total dust collected in Phase II and III is 43.7 and 46.6 per cent respectively of the weight loss of the brake shoes and drum The reason for the lower values is in part due JM to the dehydration of the chrysotile and decomposition of organic components lining Details of the contamination are found further in this report in the It is interesting to note that the secondary shoe wears from 2 to 3 times faster than the primary shoe Discounting contamination the amount of airborne dust collected per stop is 2.8 2.4 and 85.3 milligrams per stop respectively for Phases I II and III The rate of accumulation of airborne dust is about 30 times greater at 550F than for either of the lower temperatures MANVILLE RESEARCH AND ENGINEERING CENTER Report No. 456 Page 3 Spectrographic Analysis per cent in dry basis Sample No. Phase I Phase II Phase III 2 6 Composite 1 Composite 1 Composite Ignition loss at 800F 30.8 11.4 20.2 19.0 15.7 16.9 15.8 MgO approx) SiO2 approx) Fe203 approx by diff A1203 17 17 25 0.70 9 9 67 0.40 16 14 46 0.40 24 24 31 0.60 21 21 36 0.63 20 21 39 0.67 25 25 28 0.76 republicaton B203 Ba0 or Cao distrbuion Cr203 PbO general for CuO Not Mn203 - - 0.24 | 0.22 1.0 0.90 2.8 0.44 1.7 0.31 0.03 0.07 0.12 | 0.35 - 0.24 1.1 0.40 0.40 0.30 0.24 - 0.32 1.6 0.16 0.12 0.02 0.19 0.15 0.30 1.7 0.42 0.30 0.06 0.20 - - 0.29 0.30 1.7 0.21 0.40 2.5 0.42 0.42 0.016 0.06 0.23 0.25 M003 - 0.02 0.4 - - - CONFIDETAL Nio T102 JM V205 0.10 3.8 0.001 0.14 0.70 0.0014 0.18 0.20 0.17 1.2 0.08 1.7 0.0013 0.001 0.001 0.21 0.22 0.08 1.7 0.001 0.001 Loss on drying at 1050 2.7 2.0 2.1 0.7 0.6 0.4 {| Nil The composites are dust samples from the brake assembly and the box Analysis of Drum Filings in per cent as received Iron Cr Cu Mg Mn Mo Ni Si Ti V major - 0.058 - 0.17 - 0.0013 - 0.33 - 0.028 - 0.10 - 2.5 - 0.026 - 0.013 MANVILLE RESEARCH AND ENGINEERING CENTER Report No. 456 Page 5 Infrared cont'd Chart No. Sample Identification 2584 Phase II Sample 1 amorphous organics silica or silicate and trace of 2585 Phase II composite amorphous organics silica or silicate and trace of 2586 2587 Phase III Sample 1 Phase III composite forsterite and trace of organics forsterite and trace of organics 2642 republicaton 2643 2644 or stencil ink white stencil ink yellow alcohol solubles of Phase I Sample 3 acrylic resin and T102 acrylic resin and a phthalate phthalate plasticizer distrbuion 2645 2646 general for 2647 Not alcohol solubles of Phase I Sample 6 alcohol solubles of Phase I Sample 4 alcohol solubles Phase II Sample of 1 phthalate plasticizer phthalate plasticizer phthalate plasticizer 2648 MEK solubles of phthalate plasticizer Phase I composite CONFIDETAL 2649 MEK solubles of Phase III composite phthalate plasticizer JM The and infrared spectra small amounts of show that in the organic material first two phases amorphous silica were detected in the dust samples or silicate In Phase III 550F forsterite was formed by the dehydration of the chrysotile and subsequent transformation to forsterite due to heat The presence of forsterite indicates that the temperature of the brake system in Phase III was at least 600C In addition to contamination of the dust samples by inorganic components inks an organic component a phthalate plasticizer of the ink was also most of the dust samples Acrylic resin was not detected of the stencil detected in MANVILLE RESEARCH AND ENGINEERING CENTER Report No. Page 456 4 Spectrographic analysis shows that each dust sample collected is contaminated with an appreciable amount of iron particularly Sample 6 and composite of Phase I. The iron content of the brake linings is at most several per cent by inspection of the formulation It is estimated that there is roughly a 25-35 per cent iron pickup from the drum and from the area of the brake backing plate The iron pickup is abnormally high in Sample 6 and the composite of Phase I. The minor constituents found in the dust samples confirm the iron pickup based on analysis of the drum filings The chief source of the chromium lead and titanium contamination is from the stencil inks used to spray the inner walls of the box ray analysis shows that PbCrO4 and T102 are components of the stencil ink The ratio of S102 in each of the ratio for chrysotile The amount of most cases based on increase of the dust samples is essentially the same as the S102 and the MgO is reduced proportionally in F-- 203 content from brake drum contamination republicaton Ray The following ray powder diffractometer diagrams were obtained and identified or Sample Identification distrbuion Phase I Phase I Sample 2 Sample 6 Phase I composite general Phase II Sample 1 Phase II composite for Phase III Sample 1 Not Phase III composite lead chromate halos PbCr04 halos halos halos forsterite 3 MgO.S102 magnetite Fe203 chrysotile - possible trace forsterite CONFIDETAL Stencil ink white Stencil ink yellow T102 major talc minor lead chromite PbCr04 The broad halos on diagrams of the four samples indicate a considerable amount of finely divided or amorphous material JM T102 and PbCr04 analysis This are contaminants from stencil is shown by the high level of inks as confirmed by spectrographic lead chromium and titanium Infrared The following infrared spectra were obtained Chart No. 2581 2582 2583 Sample Phase I Sample 2 Phase I Sample 6 Phase I composite Identification amorphous silica of organics or silicate and trace amorphous silica of organics or silicate and trace amorphous silice of organics or silicate and trace MANVILLE RESEARCH AND ENGINEERING CENTER Report No. 456 Page 6 Pyrolysis Gas Chromatography PGC All samples were pyrolyzed under identical conditions and the fragments by gas chromatography The chromatograms of the submitted samples were the primary and secondary brake linings were analyzed compared with The original brake linings organic constituent in the showed identical chromatograms The only pyrograms was cashew resin Samples 2 and identifiable 6 of Phase I showed no evidence of cashew resin The composite of Phase I showed the cashew resin plus a number of other smaller fragments probably type components In Phase II both samples showed the large cashew fragment the composite contained more than Sample 1. In addition the composite showed a significant amount of one other fragment of much lower molecular weight not common to Phase I. Both samples of the large of Phase III showed cashew fragment almost identical chromatograms consisting mainly republicaton Light Microscopy or The major constituent of all samples is a smoky brown to opaque material which appears to be essentially amorphous They occur in flakes and masses ranging in size from distrbuion less than one micron to over 200 microns A trace of carbonate was noted sample A trace of quartz was found in Phase I composite showed a trace of glass fiber Sample 1 and composite in each Phase II general Electron Microscopy for Not Electron micrographs at a The samples were prepared total magnification of 30,000 by a rubbing out technique to X are break attached to this report up loose agglomerates The micrographs show aggregates made up of very fine material a few solid particles and traces of chrysotile fiber See Figures 1 through 7 CONFIDETAL The per cent of chrysotile fiber was determined by a modified point used for determining amounts of fiber in water samples The counts plates were made by the Packings and Friction Material Department counting method from the electron JM The results are as follows Sample Per Cent Chrysotile Phase Phase Phase Phase Phase Phase Phase I Sample 2 I Sample 6 I composite II Sample 1 II composite III Sample 1 III composite 0.531 0.065 0.65 0.087 0.255 0.551 0.390 MANVILLE RESEARCH AND ENGINEERING CENTER Report No. 456 Page republication or distrbuion general for Not CONFIDETAL JM Figure 1 micron ees 1 micron Electron Micrograph Phase I Sample 2 Mag 30,000X Brake Lining Wear Dust EMS 617A  APPENDIX I Report No. 456 Page 9 on s < t . = @ 1 s . s + m + woaoy e 2 . oo . _ * . e< * a oc Figure 3 micron Electron Micrograph Phase I Drum Shoe Mag 30,000X Brake Lining Wear and Box Composite Dust EMS 618A MANVILLE RESEARCH AND ENGINEERING CENTER APPENDIX I Report No. 456 Page 10 republicaton or distrbuion general for Not CONFIDETAL JM Figure 4 micron Electron Micrograph Phase II Sample 1 Mag 30,000X Mag 30,000X Brake Lining Wear Dust EMS 6190 INDUSTRIAL HYGIENE FOUNDATION OF AMERICA MELLON INSTITUTE 4400 Fifth Avenue PITTSBURGH Pa 15213 Report on PRELIMINARY STUDY OF BRAKE DUST COMPARATIVE PATHOGENICITY cen eewe c Ae ee ene rae CAS Re Ata Nl ag oy con for MANVILLE CORPORATION by Paul Gross M.D. Director of Research Laboratory February 14 1967 Robert T. P. deTreville M.D. Managing Director AN ASSOCIATION OF INDUSTRIES FOR THE ADVANCEMENT OF HEALTHFUL WORKING CONDITIONS INDUSTRIAL HYGIENE FOUNDATION OF AMERICA 1 Introduction As an explanation for the occurrence of ferruginous asbestos bodies in the lungs of 30 to 40 of the general population in large cities Thomson,,has indicated that urban populations are being exposed to asbestos dust and that a likely source of this dust was from the wearing down of automobile brakes Details of Preliminary Study At the request of Dr. Kenneth W. Smith Medical Director Johns ville Corporation a preliminary study of the pathogenicity of brake dust was done This dust free of iron was suspended in water and 1 ml containing 3.5 mg was injected intratracheally into rats and hamsters Some of the rats were killed four days later The lungs were examined microscopically and the changes compared with the four lesions seen in the lungs of rats injected intratracheally with the dusts of a crystalline silica b chrysotile and c kaolin respectively The chrysotile had been similarly suspended in water and given in the same dosage Results The results were as follows crystalline silica and chrysotile caused a severe inflammation best described as an obliterative bronchiolitis that could not be differentiated one from the other Whereas reactions caused by both kaolin and brake dust were also similar to one another and were of the called biologically inert type This reaction consisted essentially of the accumulation within scattered alveoli of scavenger cells filled with the respective INDUSTRIAL HYGIENE FOUNDATION OF AMERICA.INC AMERICA.INC 2 dusts There was no significant development of the connective tissue that in the case of silica and chrysotile tended to obliterate the air spaces and ducts Tentatively therefore the brake dust tested should be categorized as biologically inert Recommendations for Further Studies A proposal for further investigation of the pathogenicity of brake dust has been prepared at the request of Manville Corporation Analytical laboratories at Manville Corporation have reportedly been unsuccessful in identifying asbestos fibers in brake dust and the Industrial Hygiene Foundation's preliminary studies have shown that the dust behaves differently than chrysotile asbestos with effects on lungs which closely resemble those produced by inert dusts such as kaolin If these findings should be borne out by further studies their publication would help prove that Thomson's assumption was erroneous Essential to publication would be the development of data from inhalation of brake dust by adequate numbers of several species of laboratory animals Tentatively it is suggested that of 40 animals in each of four species guinea pigs rats hamsters and mice 30 be exposed over most of their life span two years in all except mice which have a shorter life span and require only one year to a concentration of about 100 mg the other 10 serving as controls This con- centration would be produced in an 8 x 8 x 8 chamber by means of Wright dustfeed dispersion equipment Frequent quantitation of the chamber atmosphere close INDUSTRIAL HYGIENE FOUNDATION OF AMERICA.INC 3 observation and care of the animals and extensive histopathological observations would be necessary over a three period of research The cost would be 200,000 50,000 the first two years and 100,000 the third Histological sections will receive special staining and microscopic examination by research pathologists who will take thousands of photomicrographs of their findings and use some of these to document their report which will be suitable for publication As a means of developing additional information which cannot take the place of the inhalation study but will give earlier indication of lung changes it is recommended that a similar study be done by intratracheal injection technique giving 80 animals 20 of each species listed above a single injection of near maximal dose tolerated without death These animals would be pastured for one year killed and examined by the same research pathological techniques The year study would cost 75,000 25,000 the first year and 50,000 50,000 the second the second year including the histopathological studies and preparation of a report Although not considered adequate for publication alone the results by injection would be incorporated with the inhalation study findings and be a valuable supple- ment to it Costs of the combined studies will be 275,000 75,000 the first year and 100,000 100,000 on each of the two successive years References 1. Thomson J.G. al Asbestos as Modern Urban Hazard S. Afr Med J. 77-81 1963 INDUSTRIAL HYGIENE FOUNDATION OF AMERICA.ING Tentative Outline of Brake Dust Investigation A. Intratracheal Injection 75,000 a 20 Guinea Pigs b 20 Rats C. 20 Hamsters jjj 20 Mice Single injection of maximal dose tolerated without death Pastured for one year and killed B. Inhalation 200,000 200,000 a 40 Guinea Pigs b 40 Rats C. 40 Hamsters d 40 Mice 8 x 8 x 8 chamber Wright feed dispersion at least two needed year exposure Concentrat~i1o0n0 m year exposure for mice because of shorter life expectancy year exposure for others month holding period Six months for processing and writing report Total Three Study Cost 275,000 INDUSTRIAL HYGIENE FOUNDATION OF AMERICA MELLON INSTITUTE 4400 Fifth AvenuE Pittsburgh Pa 15213 = Report on PRELIMINARY STUDY OF BRAKE DUST COMPARATIVE PATHOGENICITY for MANVILLE CORPORATION by Paul Gross M.D. Director of Research Laboratory February 14 1967 Robert T. P. deTreville M.D. Managing Director AN ASSOCIATION OF INDUSTRIES FOR THE ADVANCEMENT OF HEALTHFUL WORKING CONDITIONS INDUSTRIAL HYGIENE FOUNDATION OF AMERICA 20 Introduction As an explanation for the occurrence of ferruginous asbestos bodies in the lungs of 30 to 40 of the general population in large cities Thomson has indicated that urban populations are being exposed to asbestos dust and that a likely source of this dust was from the wearing down of automobile brakes Details of Preliminary Study At the request of Dr. Kenneth W. Smith Medical Director Johns ville Corporation a preliminary study of the pathogenicity of brake dust was done This dust free of iron was suspended in water and 1 ml containing 3.5 mg was injected intratracheally into rats and hamsters Some of the rats were killed four days later The lungs were examined microscopically and the changes compared with the four lesions seen in the lungs of rats injected intratracheally with the dusts of a crystalline silica b chrysotile and c kaolin respectively The chrysotile had been similarly suspended in water and given in the same dosage Results The results were as follows crystalline silica and chrysotile caused a severe inflammation best described as an obliterative bronchiolitis that could not be differentiated one from the other Whereas reactions caused by both kaolin and brake dust were also similar to one another and were of the called biologically inert type This reaction consisted essentially of the accumulation within scattered alveoli of scavenger cells filled with the respective INDUSTRIAL HYGIENE FOUNDATION OF AMERICA 2 dusts There was no significant development of the connective tissue that in the case of silica and chrysotile tended to obliterate the air spaces and ducts Tentatively therefore the brake dust tested should be categorized as biologically inert