Document 8VzYY1ooznLYVmak3NJ3B3gwd

FMSI 06023 FMSI 06024 \ "f .,,._...~,. y;. iff 'f-3 y -)I &"-j2- '1 3~ \1 y. . H " y ... Lo y.. ,, AA-il M OJffo~d STOCK No. 1152~ '1ADE IN U. s. A. FMSI 06025 ASBESTOS INTERNATIONAL ASSOCIATION j (Limited by Guarantee) 6R GLOUCESTER PLACE, LONDON WtH 3!-IL I\.1EMORANDUM TO: All Member Associations FROM: Sir Neville Stack AIA/7 /3 10 July 1979 RESEARCH REPORT - ASBESTOS INVESTIGATIONS INTO HEALTH HAZARDS THROUGH DUSTS ENITTED BY BRAKE LININGS CONTAINING ASBESTOS Issued by the German Federation of Industrial Accident Insurance and Industrial Safety Corporations e.V. Attached is a translation of the significant parts of the abovementioned document which indicate that it is a very important piece of research. The report is the result of considerable work by more than one independent institution, and therefore should carry considerable weight with authorities. The main conclusion is that when a brake has been in use the dust emitted from the lining contains virtually no asbestos, which means that the effect on the environment is almost nil. However, it is stated that all the investigations have been done on German brakes, and it is understood that there is a considerable difference in the asbestos content of American brakes. It is also pointed out that there is a difference in usage between America and Germany; the Americans use a larger brake pad End do not drive so fast, which means that less heat is ge0erated \,'hen the brake is applied. We are obtaining copies of the original GelTian report, which will be sent to Member Associations. Would you please make sure that companies within your Associations which manufacture brake linings are advised of this report. Sir Neville Stack FMSI 06026 RESEARCH REPORT ASBESTOS INVESTIGATIONS INTO HEALTH HAZARDS THROUGH DUSTS EMITTED BY BRAKE LININGS COOTAINING ASBESTOS. .. I I --I --~"'---- Issued by the German Federation of Industrial Accident Insurance and Industrial Safety Corporations e.v. BERLITZ Translations FMSI 06027 FOREWORD Because of its particular physical and chemical properties, asbestos has become a much sought-after natural product. Its resistance to high temperatures, inflammability and fibrous structure have helped to solve numerous technological problems to the extent that we now encounter asbestos in a multitude of products. Unfortunately however, asbestos is hazardous to health - especially its carcinogenic properties have arrested the attention of the public in more recent times. Long before asbestos made the headlines, the Industrial Accident Insurance and Industrial Safety Corporations of Germany studied the risks of asbestos, and by issuing an accident prevention code were able to implement and intensify technical and occupational medical preventive measures. One of the questions posed in this process was whether the dust emitted by brake linings which contain asbestos is also capable of causing asbestos illnesses. This is a vital question, since upon its answer depends whether or not a large number of motor vehicle mechanics in particular need to undergo regular medical examinations. The present scientific investigations are intended to throw light on this subject. The many forms which the problem took i~actual research however is demonstrated by the fact that four scientific institutes took part in the research project. Organisational procedures too entailed many problems; as one example, to ensure the scientific validity of -;:he results more than 200 motor vehicle mechanics and employees in ~~e brake lining industry in the Federal Republic had to be found ho had had more than 10 years of exposure to dust, in order to have them examined at the Institute for Occupational and Social Medicine in Erlangen. The final phase of the joint investigations revealed yet another important aspect: similar investigations in the USA had come to conclusions that did not always coincide with our own. This is due to the fact that American brake linings are essentially different from German in terms of composition and hardness, a requirement which has to do with different driving habits in the USA {speed limits). We shall have to deal with this new aspect in the near future, especially since increasing numbers of American motor vehicles are to be expected on the German market. ./. ' BERLITZ Translations FMSl 06028 2. I' Foreword - continued. This research project was Linanced with the aid of the Federation of German Industrial Accident Insurance and Safety Corporations, the General Committee of the Iron and Steel IAISC and the IAISC of the Chemical Industry. May we express our thanks to all those who have contributed to the successful outcome of this report. Hopf Chairman Dr. Bischoff Vice-Chairman Bonn, December 1978 BERLITZ Translations FMSI 06029 \, 'I,_ t I t ' .... CONTENTS - A. Research Brief and Measurement and Assessment of Asbestos-dust Concentration by G. Heidermans, G. Ktlhnen and A. Schlitz Dust Research Institute of the Federation of Industrial Accident Insurance and Industrial Safety Corporations e.v., Bonn. and R. Prochazka Bavarian State Institute for Industrial Safety, Munich B. Supplementary Analytical Investigations to Section A by. G. Heidermans, G. Riediger and A. SchUtz Dust Research Institute of the Federation of Industrial Accident Insurance and Industrial Safety Corporations e.v., Bonn Page 7 33 c. Occupational Medical and Epidemiological Investigations by H-J Woitowitz, H. Valentin, R. Henke, R.H. Woitowitz .and K.P. Hol::::hauser Institute for Occupational and Social Medicine of the Polyclinic for Occupational Diseases at the University of Erlangen-Nuremberg, and Institute for Occupational Medicine of the University of Giessen D. Experiments on Animals by W. KlosterkBtter and J. Bruch Institute for Hygiene and Occupational Medicine at the University of Essen E. Conclusions and Recommendations 39 93 99 BERLITZ Translations FMSI 06030 .. Pages 30/31 SUMMARY The investigations into the dangers of dusts emitted by brake linings containing asbestos carried out by the Dust Research Institute of the Federation of Industrial Accident Insurance and Industrial Safety Corporations and the Bavarian State Institute for Occupational Safety within the scope of the overall research programme may be summarized in terms of their results as follows: 1. Brake linings used in the brake systems of motor vehicles con~ain 10 to 70 % by weight of asbestos; this value usually lies between 20 and 30 % by weight. In all the cases examined, the asbestos used was Chrysotile; other types of asbestos are obviously not used. 2. The principal dust sources encountered in the handling of asbestos brake linings are : a) in manufacture, the finishing stage comprising the operations grinding, drilling, turning, sawing and milling, b} in the vehicle workshops, the brake service centres with the operations! grinding and turning of brake linings as well as flushing the I i dust from brake drums. 3. In the finishing stage of lining manufacture, the operations grinding and drilling may as a rule be regarded as ongoing operations. The average expsoure time for the operative is 6-8 h/shift for grinding 4-6 h/shift for drilling. The operations sawing, turning and milling are carried out only occasionally and only by some lining manufacturers. In motor vehicle workshops, the operations that suggest the emission of asbestos dust are grinding, turning and flushing, although these operations are generally short-term only. The time of exposure for operatives in the workshop is difficult to assess accurately, but we can assume the following averages < 1 h/shift, usually < 3 h/week for grinding and t~ning < 1-3 h/shift for brake drum flushing. 4. The Chrysotile asbestos content in suspended dust found at the finishing stage of brake lining manufacture is on average 20 % by weight and thus in the order of the volume of asbestos contained in brake linings themselves. Conditions in vehicle workshops for the operations grinding and turning are similar, although the values are on average lower here. ./. BERLITZ Translations FMSI 06031 I' Pages 30/31 - continued 4. continued. It was not possible to find clear evidence of the presence of Chrysotile in dusts caused by brake drum flushing. By the fact of its morphology the dust contained practically no fibres at all. 5. The microdust concentrations of Chrysotile asbestos during the operations grinding, drilling, sawing, turning and milling in finishing during brake lining manufacture were just above and below the limit value of 0.15 mg/m'. In the brake maintenance departments of motor vehicle workshops, the limit for Chrysotile asbestos during the actual operations of grinding and turning is in fact exceeded. In the workshop area however the average values were considerably below this limit. Since no evidence of ~sbestos in dusts caused by brake drum flushing can be provide~, the assessment was based on the MAK value for inert dust of 8.0 microdust/m3 This value was considerably exceeded during the actual flushing operation. Concentration in the work area however was on average below this MAK value. 6. Test bed and laboratory experiments showed that : a) by mechanical loading (microgrinding) the fibres located in the friction area during the braking process are destroyed to such an extent that practically no fibres can be found in the resulting friction dust, in terms of morphology. .. b) Under the influence of temperature, the crystalline lattice of Chrysotile probably transforms into an amorphous intermediate phase. It must be assumed that local tenperatures in excess of 500C are generated in the friction surface. c) The tempering of samples taken from crushed brake linings in the laboratory at over 800C causes the formation of Forsterite. Under test bed conditions, Forsterite in the friction dust could only be found with very high asbestos contents (some 60%) in the friction lining. In none of the examined cases was it possible to detect Forsterite in brake drum dust as generated by flushing in the vehicle workshops. BERLITZ Translations FMSI 06032 Page 37 CONCLUSIONS The results of the supplementary investigations confirmed that the asbestos content in brake friction dust is considerably lower than in the brake linings themselves. There were however wide variances in the extent of asbestos contained in the friction dust. While only traces of Chrysotile asbestos (10-3 to 5 10- 1 %) were detected in the friction dust samples from 40 German vehicle workshops, there are American brake linings whose friction dust may contain 10 to 30 % Chrysotile asbestos. Asbestos in the order of 2 to 4% has been detected in the friction dust from French workshops. The reasons for this should first of all reside in the varying composition of the friction linings themselves, and secondly in the variety of conditions under which they are used. Thus European and Japanese linings contain as a rule 10 to 30 % asbestos, while American products contain as much as 60%. In addition, American vehicles are fitted with larger brakes than, say, German vehicles and are generally driven at lower speeds with the result that the heat loading on American brakes is lower. However, the wear and hence the dust emission of the linings is largely determined by the temperature. Even the type of bonding agent used is significant. Thus linseed oil which is used as a bonder for linings in light-duty brakes starts to decompose at as low as 230c. These investigations into the asbestos conte~t of brake lining friction dust in motor vel icle brake drums represent an important supplement to the pertinent results of the research programme into hazards to health caused by dusts emitted by asbestos friction linings. They confirm those findings and support the conclusions from them in so far as German brake linings are concerned, but demonstrate on the other hand that other circumstances may be encountered, at least in the case of American linings. The reasons for these differences have yet to be fully clarified. BERLITZ Translations FMSl 06033 Pages 59-66 DISCUSSION OF RESULTS Man's need for fast transport facilities is as old as civilization itself. However, the high speedsmade possible by modern technologies have brought about many new dangers. Apart from fire and war, the braking of energies of motion is perhaps the greatest among the self-induced, exogenous hazards to human life. In order to minimize these risks, people employed in the friction lining industry, the lining processing sectors of the motor vehicle industry and the brake maintenance departments of vehicle workshops and garages are contributing valuable work. Friction linings on the other hand . contain asbestos, a material hazardous to health, although in composite form. The amount of Chrysotile asbestos in friction linings is between 10 and 73%, usually between 20 and 30 %. According to American assessments, each private car consumes some 3 or 4 sets of brake linings and 2 clutch linings in its life, while goods vehicles and public transport vehicles require many more. In the highly motorized industrial nations, this fact is expressed as a production figure for brake and clutch linings containing asbestos, of which not less than 6500 t and 7000 t were produced in the Federal Republic of Germany in the first quarter of 1971 and 1972 respectively. The annual asbestos consumption of the USA for the manufacture of brake linings was approx. 55,000 t and approx. 2000 t for L~e production of clutch linings. Tne latest estimates for 1972 in the USA gave a total figure of 907,871 persons potentially exposed to lining dust through their occupations: 833,535 motor mechanics, 67,679 garage workers and some 6,657 employees in the friction lining industry. There are no reliable figures on persons in the Federal Republic of Germany currently exposed to lining dust and hence to asbestos in the course of their work. And there is even less information available in Germany on the nature and extent of the health hazards that can be causally attributed to such exposure with the degree of probability required for purposes of statutory accident prevention. So what is the current state of medical knowledge on this ? Bibliographical material on the subject shows that persons occupationally exposed to brake lining dust r::an expect a fibrogenous and eJen carcinogenic health risk , s a result of asbestos effects. Thus in the USA in 1963, out of 7510 employees in the friction lining industry 29 deaths of asbestos 'pulmonary cirrhosis were recorded (= 3.86%). In 21 of the 29 deaths, asbestosis was the primary cause. More recent epidemiological findings by saikoff's working party point especially to the asbestos risk among New York automobile mechanics. A provisional cross-sectional study of 84 active and 6 retired (for age reasons) automobile mechanics each with at least 10 years working experience behind them, and of whom some 2/3 had been engaged in brake maintenance, revealed diminished vital capacities in no less than 29% of the subjects and radiological changes in terms of asbestos inhalation effects in 27%. More particularly, these 24 subjects revealed minor irregular shadows of type s or t with a scatter of 1/0(9 x), 1/1(6 x), 1/2(2 x) and 2/2(2 x) as well as indications of pleural fibrosis (~ 1 a) and/or pleural calcification /. FMSI 06034 BERLITZ Translations .. Discussion of Results - continued. (5 x) In Great Britain 14 out of 718 recently diagnosed asbestosis cases (= 2 %) in the years 1955-1969 are persons occupationally exposed to brake lining dust. Epidemiological investigations in Italy revealed 59 cases of asbestosis out of 204 employees in the friction lining industry. In Switzerland on the other hand, of 39 persons in automobile brake maintenance, there was only one questionable instance of asbestosis. Neverthless regular control examinations of this occupational group are regarded as necessary. Less comprehensive is the available knowledge of carcinogenic asbestos risks in exposure to friction lining dust. In Great Britain in 1965 Newhouse and Tnornpson recorded 1 mesothelioma patient following occupational "crocidolite (blue asbestos or ironstone} exposure during brake lining manufacture and in 1974 Greenberg and Davies recorded a further case of mesothelioma after exposure of a motor mechanic. In the USA, Enterline and Kendrick - 1967 - reported indications of a marginally increased mortality rate from carcinomae of the breathing organs among employees in the friction lining industry. From Canada, McDonald and his colleagues in 1970 reported 2 cases of mesothelioma following occupational exposure to asbestos in the fitting of brake linings plus a further case of mesothelioma after exposure during brake lining manufacture. In West Germany in 1972, Otto published the case of a 50-year-old fitter with pathological-anatomical pleuramesothelioma after many years employed in the fitting of brake linings. A study of available subject literature - especially with regard to fibrogenous asbestos risks - shows however that the particular circumstances of exposure to brake lining dust were frequently inadequately investigated to facilitate a differentiated consideration of the hazards. More particula~ly, i t is essential to distinguish exposure to dust from new or used Leake linings. Technical investigations into dust in recent years have repeatedly shown that the dust generated by lining friction - as opposed to dust during the finishing and hsndling of new linings - as a rule contains only traces of free Ch~~sotile fibres, i.e. of the order of 1%. Even SchUtz' working party was unable to provide clearer infraredspectrographical evidence of Chrysotile within the scope of this joint research programme, using site measurements as well as laboratory and test-bed experiments on dusts caused by brake drum flushing with compressed air. Under phase-contrast and electron-microscopic scrutiny, the dust contained merely isolated fibres which could not even be definitely identified as asbestos. The assessment of dusts in the air-flushing of brake drums was therefore initially based on the MAK value for inert microdust of 8.0 mg/m' . .f. BERLITZ Translations FMSI 06035 Discussion of Results - continued. By contrast we find some reports from the USA with partially high fibre concentrations in brake drum dust during peak samples lasting several seconds. Hatch for example has found peak values of 43 ~ 2.1 fibres/ml during drum flushing, while Knight and colleagues have found as many as 87 fibres/ml. Tne latest findings by Selikoff's working party on flushing operations of car brake drums point in the same direction, with recordings of 6.6, 13.6, 13.8 and 29.4 fibres per ml. The hypothesis posited at the beginning of this discussion must be seen against this background: Does occupational exposure over many years to dusts emitted by asbestos brake linings of employees in the 3 most important risk sectors have medically probable, demonstrable and detrimental subsequent effects on the pulmo-cardial system, especially in terms of specific fibrogenous asbestos inhalation consequences ? Our occupational medical and epidemiological investigative results are thus based upon the knowledge of work-specific differences in occupational exposure to brake lining dust. As a result, 3 aspects are of particular importance: 1. The formation of adequate random sampling. 2. The representativeness of occupational characteristics for the following areas: industrial finishing in friction lining ~anufacture (risk group a) brake maintenance services, with exposure primarily during the operations of grinding and turning of linings (risk group b) and brake maintenance services, with exposure primarily during flushing and brushing out of brake drum dust (risk group c). 3. A period of 10 years or more occupational exposure to the development of asbestos effects. Thus far, the epidemiological artifice of a casuistic cross-sectional study with retrospective assessment would seem to be adequate for the hypothesis under scrutiny. However, the results obtained are unable to give any answers to the following essential questions: A) What type and how great are the carcinogenic risks of o:.:cupational exposure to brake lining dust ? B) Does the surprisingly often demonstrated finding of so-called chronic-obstructive bronchitis, as opposed to fibrogenous asbestos-inhalation, represent an overfrequent risk of occupational exposure to brake lining dust ? ./. BERLITZ Translations FMSI 06036 Discussion of Results - continued. C) What effect has the change in workplace conditions since the beginning of the Fifties had on the prevalence of the consequences of asbestos inhalation, e.g. through - improvements in dust protection by way of extraction technology, - increasing use of disc brakes for private cars, and - flushing of brake drums by means of cleaning detergents. The answers to questions A) , B) and C) would require specific longitudinal - as opposed to cross-sectional -studies including future measurements as well as suitable comparative groups. Re 1: Our random samples from the individual risk groups each containing between 43 and 63 persons were kept satisfactorily large. With 50 separate companies throughout West Germany and the resultant organisational difficulties, this was only possible in close cooperation with the Headquarters for Accident Prevention and Occupational Medicine of the Federation of Industrial Accident Insurance and Safety Corporations in Bonn. Re 2: The representative .ess of activities in the 3 key risk groups \1as ensured in a variety of ways: - The selection of each subject and the collation of important dustprotection data at the workplace was carried out by experienced technical supervisors with many years service in occupational safety; - The investigative results reported by SchUtz' working party on dust hazards through asbestos brake linings relate. to approx. 85% of the workplaces in those companies in which our subjects were employed; - Tne additional detailed survey of occupational and industrial case histories carried out by an occupational physician extends to the entire working life of each subject. In this way it was found that a sharp delineation in brake maintenance services between activities involving exposure to dusts emitted by new linings on the one hand and brake drum dust on the other does not appear admissible, at least for the period of the subject's entire past working life. In other words, the random sample of risk group c) contains not just employees who have only always flushed or brushed out brake drum dust. It is difficult to ascertain the time spent on operations such as grinding or drilling of unused linings. Thus for example of the ./. BERLITZ Translations FMSI 06037 Discussion of Results- continued.' 19 men with suspected findings in terms of initial consequences of asbestos inhalation (Type II), or with minimal {Type III) and equivalent findings (Type IV), no less than 11 stated that they had handled unused brake linings in the manner mentioned in addition to their primary activities of flushing and brushing out brake drums. Re 3: With regard to the exposure period, a process of elimination guaranteed roa minimum of years occupational exposure to brake lining dust in each case. This fact is expressed in the left-shift spread of exposure periods with arithmetical averages between 16 and 21 years and maximum values between 25 and 44 years (cf. Table 6 and Fig. 2). The foregoing points indicate both possibilities and limits of a discussion of results, on the assumption that the occupational medical appraisal of the findings on a person exposed to asbestos dust must today be basically three-dimensional. By this we mean both the aspect of occupational disease diagnosis and rival health hazards, which could cast doubt on suitability for hazardous work in accordance with the principles .of the industrial safety corporations. This situation was taken into account by the definition of types of findings as I=~ AIF probable, II~ AIF possible (suspect findings), and III = ~ AIF unlikely on the one hand, and on the other the rival finding designated as IV ~- This in turn was based on suitable procedures of primary and secondary data gathering, such that the detailed infomation on each subject could be reducedrom more than 100 target features - with the extensive elimination of perturbances to one or two types of findings. The risk assessment is thus based on the frequency of peculiarities noted according to types of findings in work-specific sub-groups. After consideration of the pros and cons the assertion of a tolerable residual risk for findings in terms of probable asbestos inhalation consequences Type I) of less than 1 % would appear acceptable under the prevailing circumstances. If we look through the results submitted, we find that there is evidence - with the degree of probability decisive for the area of statutory accident insurance - that many years of occupational Exposure to brake lining dust can lead c~usally to fibrogenous asbestos inhalation effects. But an assessment differentiated by risk groups points to apparent differences in the risk of disease, these differences arising out of the frequency of symptoms in findings group type I and to a certain extent in II. We should point out here that the definition of findings type I - as opposed to type II - in terms of occupational medicine is based on a "reasonable suspicion" of an occupational disease under Section 5 of the 7th BKVO*. *BKVO Berufskrankheitsverordnung - Occupational Disease Code. BERLITZ Translations FMSI 06038 Discussion of Results - continued. The number of occupational diseases to be indicated under Figure 30 of the Appendix to the 7th BKVO is 3 in risk group a} and 2 in risk group b). In relative terms, 5.9% and 3.2% respectively of the male subjects in both risk groups clearly exceed the tolerable residual risk of less than 1 %. To this fact must be added that the employees in risk group a), while being some years older on average, had nevertheless had some years less exposure to brake lining dust than the subjects in risk group b). The relative frequency of insured persons with suspect findings in terms of potential asbestos inhalation effects (Type II) 'is 16% in both sub-groups. For these persons intensified monitoring by for example more frequent examinations is to be reco~~ended in accordance with principle G 1 of the industrial accident insurance corporations. All in all, we may assume that the male groups are exposed to a somewhat higher disease risk in the finishing stage of the lining manufacturing industry (risk group a) than in motor vehicle maintenance, especially with exposure to dust from new and used brake linings (risk group b). Female employees are only engaged in lining manufacture to any noteworthy extent. The random sample of 43 female workers did not reveal any peculiarities compared to their male counterparts in terms of age distribution and length of exposure to brake lining dust (Table 6 and Fig. 2). The results of the investigations however differ considerably. The probable presence of fibrogenous asbestos inhalation effects (Type I) was found in none of the subjects, while poential effects (suspect findings, Type II) were .only approx. half as frequent (7%) as in males. The length of exposure to dust from the drilling (twice) and grinding (once) of unused linings for the 3 women of findings Type II was 18, 20 and 11 years respectively. The reasons for the differences between the sexes with regard to probable and possible inhalation effects may be discussed as follows: - the known difficulties of early radiological diagnosis of fibrogenous asbestos inhalation effects in women throug~ mam8ary shadow superimposition; - the high percentage of non-smokers among women (approx. 70%) , as opposed to their male colleagues (approx. 24% non-smokers), and - less dust co.:,centrctions at women's workplaces despite nc::;i:---.ally similar work in drilling, grinding, sawing and turning, e.g. as a result of smaller workpieces. Rival findings of Type IV are numerically predominant in the female employees. Their relative frequency exceeds by approx. 35% that of the three male random samples (Table 8) . The main cause of an assumed unsuitability for activities at risk through asbestos dust for 12 out of the 15 women (80%) - despite the large proportion of non-smokers - is represented by varying degrees and configurations of chronic-obstructive bronchitis. The same statement is also true .I. BERLITZ Translations FMSI 06039 Discussion of Results - continued. for 10 of the 12 male workers (83%) with Type IV findings in risk group a). A long way behind comes obesity in terms of excessive or extreme overweight as the second most frequent cause of unsuitability in males (once) and females (3 times) in risk group a). Only approximately half the men (45%) and women ~51%) in this risk group showed a spectrum of findings in the normal range (Type V). These included subjects of both sexes with as much as 25 years length of occupation. One of the causes of these varying effects of quantitatively and qualitatively potentiall equivalent conditions of exposure can be stated as the in( vidual's disposition. The two employees in risk group b) with Type I findings already mentioned have certain particular features. Investigations in each case detected the combination of findings of Type I with thoseof Type IV. In both instances, the effects of asbestos inhalation are rivalled by chronic-obstructive bronchitis with nicotine ~buse and moderate overweight. In addition, the duration of exposure to brake lining dust with grinding and turning and to brake drum dust during flushing or brushing out of bral.;:e drums of 29 and 37 years is high in relation to the ages of 43 and 53 respectively. Hence the age of entry into the risk occupation is calculated as being 14 and 16 years respectively. In 5 of the 10 employees with findings of initial asbestos inhalation effects (type II) also, the age of entry into the brake maintenance trade is 14 to max. 18 years (cf. Fig. 5). The average expcsure period of_all 10 employees in this group is 20 years and thus also comparatively high. The frequency of findings in the norrr;al range (Type V) in risk group b) employees with many years of exposure corresponds -at 47.6% -with that of risk group a) . The lack of evid2nce of fibrogenous inhalation effects (~ype I) in the 53 men in risk group c) may be taken as an indication of a relatively low workplace risk factor, especially in view of their long years of exposure. Tne reader is moreover referred to the detailed casuistic description of the examination results on 4 employees with findings of initial inhalation effects (Type II). Here we find ~e following peculiarities - exposure co:::-mJences ~-n 15th year (twice), - exposure not only to brake drum dust but also to dust from unused linings during grinding and turning (once) , and - differential diagnosis rendered difficult by findings combination II/IV (4 times). ./. BERLITZ Translations FMSI 06040 Discussion of Results - continued. In another 5 men {9%) there are other disorders which restrict the functioning of lungs, heart and circulation. Details as to the distribution of diagnoses over the male and female Harkers in the three risk groups are shown in Table 9. The prevalence of chronic-obstructive bronchitis as a non-suitability criterium is: - 19.2% related to all 210 subjects, -between 65 and 89% related to the 53 subjects with ~ype IV findings. On the basis of our long years of occupational medical and epidemiological experience, we can state that these frequency figures are notably high in comparison with investigative results from other g~oups of subjects exposed to dusts. It should be pointed out here G~at measurements of respiratory capacity by Selikoff's working party found indications of obstructive ventilation disorders in 32 out of 87 motor vehicle mechanics, i.e. 37%. In accordance with the epidemiological investigative results set forth here on the subject of health hazards through dusts emitted by brake linings containing asbestos, the following assessments of ~he material hypothesis, conclusions aild recommendations \.;ould seeiil to be adequately covered, all due care being considered ~~~~==~~~!-~!-~~!~~~~~ 2xr~!~~~~~ The Iilaterial hypothesis must be assumed in the follo\Jing fsrm: Long years of occupational exposure to dusts t=mitted l:y br=.ke linings containing asbestos may, in employees in t\.Jo of the tJ-,ree :-:-;<Jst important risk groups, and in individual cases, provoke detrimental repercussions on the pulmo-cardial system, and more partic,Jlarly by way of specific, fibrogenous asbestos inhalation effects, such repercussions being demonstrable with a degree of probability acceptable in terms of specialist internal and occupational medicine. Sl.WJ.KlillY Since 1973 the Fedel-al Republic of Germany has had far-reaching regulations on the l~otection of persons exposed to asbestos. Tnis raises the question of whether persons occupationally exposed to dusts emitted by brake linings containing asbestos should be generally conside:!:"ed as in danger from fibrogenous inhalation effects or not. To investigate this workplace-related proble~, a cross-sectional study of a selected group was carried out with retrospective considerations. This group consisted of 210 employed men and women each with at least 10 years' exposure to brake lining dust in 3 risk groups and from approx. 50 different firms. The data gathered for each subject resulted in ./. BERLITZ Translations FMSI 06041 Discussion of Results - continued These findings are rivalled in each instance by an initial to moderate obstructive bronchitis with reasons for suspecting an initial fibrogenous inhalation effect. It is known that peribronchitic alterations in the X-ray picture ~an however lead to qualitatively similar, small, irregular and linc:ar .. hadm:s as a nascent pulmonary asbestos fibrosis. Thus the irnportfu)Ce of the Type II findings in 7.5% of the random sample is sor.Jev:hat diminished, and the percentage of men in risk group c) with findings in the normal range (Type V = 64%) clearly exceeds those of the other three groups (45%, 51%, 48%, cf. Table 8). In terms of occupational medicine, we should finally looJ.. at another result. of this study in greater detail. This is the frequency and reasons for restricted suitability and/or unsuitability for work at risk from asbestos dust, which have been summarized here as rival findings of Type IV, as based on the non-suitability criteria as contained in Fig. 3.3 of principle Gl*. The application of these criteria to all the 210 subjects with many years of exposure to brake lining dust in all three risk groups reveals in no fewer than 53 subjects (= 25.2%) medical doubts about the continuation of their former activity. Two diagnoses are by far the most significant reasons : - the chronic-obstructive bronchitis of 41 of the 53 persons with Type IV findings (= 77%), and - obesity in terms of excessive or extreme overweight (13%). Table 9: Absolute and relative frequancies of important diagnosis groups as reasons for restricted suitability and/or non-suitability for work at risk from asbestos dust for n = 53 employees exposed to brake lining dust, subdivided into risk groups and sex. Diagnosis Group Risk Group Total Chronic-obstructive bronchitis Obesity Other disorders Total Gl* - Danger fro~ mineral dust hazardous to health. BERLITZ Translations FMSI 06042 Discussion of Results - continued. approx. 200 d.etails - over 40,000 in all - both on their case histories, with special consideration of occupation and workplace, as well as on the findings. The subsequent detailed occupational medical and internal investigations made use of physical, clinical, ECG, X-ray and the latest pulmonary function analytical processes. Tne occupational medical evaluation of the findings on a subject exposed to asbestos must today be carried out three-dimensionally. The comprehensive data material had to be reduced in terms of fibrogenous inhalation effects according to the quality of the findings to a few types with definite degrees of diagnostic certainty : Type I~ probable effects; Type II~ possible effects (suspect findings); Type III ~ no assumption of effects. Rival and normal findings were grouped under Type IV and Type V respectively. The risk assessment is primarily based on indings in terms of probable effects (Type I). Suspect findings in terms of initial effects (Type II) were not however disregarded. The prevalence of findings of Types I and I respectively were: a) 5.9% and 15.7% for 51 men engaged in the industrial finishing of brake linings or processing them in the automotive industry (risk group a), 0.0% and 7.0% for 43 women in the same risk group a), b) 3.2% and 15.9% for 63 men processing mainly used and unused brake linings in motor vehicle brake maintenance (risk group b) , c) 0.0% and 7.5% for 53 men flushing or brushing out brake drucs in the bra~e maintenance trade (risk group c) . From this we can conclude that long years of occupational exposure to brake lining dust can causally lead to fibrogenous inhalation effects with the degree of probability decisive for the area of compulsory accident insurance. The risk of disease would appear to be somewhat higher for group a) than for group b), and is relatively lowest for risk group c). A rival finding is the above-average prevalence in 19.2% of the 210 subjects examined of chronic-obstructive bronchitis as a non-suitability criterion for jobs at risk through asbestos. . I. BERLITZ Translations FMSI 06043 Discussion of Results - Conclusion. The results obtained justify the realization of occupational medical prevention preferred for employees in risk groups a) and b) Details proposals shall be submitted on this. It is also recommended that ways be found to ensure in future that youths under the age of 18 years are not exposed to dusts emitted by brake linings containing asbestos in risk groups a), b) and c). BERLITZ Translations FMSI 06044 Page 95 DISCUSSION OF RESULTS In terms of carcinogenic properties there were distinct differences between the two dust samples. Sample AB I Hith a 45 % tumor incidence possesses unequivocal carcinogenic properties, for Hhich the asbestos fibres contained in the dust sample should be primarily responsible. Compared wjth the results given in subject literature, this tumor rate "ust be regarded as relatively high. It is more difficult to assess the results of the second test group AB II. A tumor rate of 11 % (n 22) is around the limit of a potential spontaneous frequency. In DQmerous dust control groups of investigations by Pott et al. the tumor rate was betHeen 2 and 8 %, with a maximum of 10 %. We can conclude therefore that the occurrence of 11 % tumors with the given dust dose does not safely exclude the carc:nogenic effect of the AB II dust. If we further remember that 40 animals had already died spontaneously by the appearance of the first tumors at the "9 months" test period, the tmnor rate Hould increase to just 14%. With regard to the fibrogenous properties there were distinct differences between the two dust samples. Sample AB I develops definite fibroblastic properties under the given test conditions, while AB II shows rare and also very minor co~lescences with a single application of 50 mg per animal. Subject 1 iterature shows that tmnors froo fibrous dusts arise under concentr:-;tions that no longer exert any fibroblastic effects. Hence no indirect conclusions can be dra\vn from the extent of the coalescences with regard to the presence or absence of oncogenous properties of sample AB II. BERLITZ Translations FMSI 06045 Pages 94,95 RESULTS Macroscopically, all animals showed distinct dust nodules on the o~entum as well as on the liver, pancreas and other organs. In the group AB I growths in the upper abdominal cavity between omentum, liver, pancreas and stomach were quire marked in almost all animals, such that a fibrogenous effect must be ascribed to this dust. In Group ~E II there v"ere only minor growths in a few animals; no specific fibrogenous effect should be inherent in this dust. In both groups (AB I and AB II) the first tumors appeared 9 months after the start of experiments. At that time 39 rats in Group AB I and 40 rats in Group AB II were dead. The tumors were either solid, sizeable (up to 5 em) growths primarily on the stomach, liver or lower abdominal area or disseminated to matchstick-sized nodes spread throughout the entire peritoneal cavity. Haemorrhagic ascites with grit-like white grains were often exuded on opening the abdomen. Large, subcutaneous tumors were also found at various parts of the body. Histologically speaking, the abdominal tumors were mesotheliomae, sarcomae and carcinomae at various stages of development; transitional stages of the various types were frequently observed. The cumulative appearance of tumors over a period of time is shown in Figure 1, which shows abdominal tumors of both test groups. Two additional graphs show the occurrence of tumors with haerrorrhagic ascites. By the end of the experiments, 89 animals in Gro9p ~B I (=45%) and 22 in Group AB II (=11%) showed tumors of the abdo~en, and in 30 cases (AB I) and 5 cases (AB II) this was acconpanied by h~emorrhagic ascites. Tne occurrence of subcutaneous tumors is reflected in Figure 2. The differences in frequency ar~in the usual range of distribution. BERLITZ Translations FMS\ 06046 Page 100 to 102 It is a generally accepted fact in practice and science today that occupational exposure to asbestos dust can become a health hazard at the most varied kinds of workplaces. The Legislature have acknowledged scientifically proven findings and have taken account of both the fibrogenous risk as No. 4103 (asbestos dust pulmonary disorder) and the carcinogenic risks with No. 4104 (asbestos dust pulmonary disorders in conjunction with lung cancer) and No.4105 (asbestos-induced mesothelioma of the costal pluera and peritoneum) in the schedule of occupational disorders. Apart from other factors, the concentration and duration of inhalation of asbestos microdust are of vital importance. Particular difficulties arise in connection with an appraisal of the health risk for those occupational groups exposed to very slight dust concentrations or exposed to sporadic concentrations only. Those persons working in motor vehicle workshops on brake repairs are especially difficult to assess. The following conclusions may be drawn from the investigations: Group a: Industrial Machining and Processing of Brake Linings This group comprises persons handling brake linings in the finishing stages of ma~ufacture (e.g. sawing, grinding, drilling, turning and milling) as well as those carrying out comparable work in the automative industry. The average Chrysotile microdust concentrations found in these activities are in the range of 0.09 to 0.20 mg/m3 Thus the results of measurements are within the ra~ge of the current!~ value of 0.10 mg/m3 In terms of occupational disorders, persons carrying out these activities, and especially three of the 94 examined cases, showed probable fibrogenous asbestos inhalation effects. Tne experiments carried out on animals show that dust samples taken from this area possess both fibrogenous and carcinogenic properties. All the results correspond in so far as they call for measures for technical and medical safety at work in the industrial machining and processing of brake linings. We therefore recommend that 1. technical protection measures such as improved enclosure of the dust sources, increased air extraction etc. be implemented to keep the concentrations of Chrysotile microdust below the TRK value, and ./. BERLITZ Translations FMSl 06047 .F I 2. 2. persons carrying out the afore-mentioned activities undergo occupational medical preventive examinations according to principle Gl of the industrial insurance and industrial safety corporations by way of - general basic examination - follow-up examinations at mediu_rn intervals (e.g. two years) and - detailed examinations at the usual intervals (five years). Grouo b: Han~ningof Brake Linings This group comprises persons handling unused and used ~rake linings in motor vehicle workshops. To a lesser degree of time (approx. 20%) brake ~~~s are also blow-flushed or otherwise cleaned. Tne concentrations of Chrysotile microdust founds in these activities are between 0.03 and 0.79 mg/m3 The results measured are thus distinctly above the current TRK value for Chrysotile. It must be remembered however that the proportion of these activities are often just one hour per shift or less tha~ three hours per week. Of the 63 persons examined in this group, two showed probable fibrogenous inhalation effects from asbestos. The r,esults indicate therefore that, with regard to the hand r~Jachining of brake linings, measures for technical and oedical safety at work cannot be disregarded. No animal experiments with group b dusts were carried out since these dusts are not essentially different from those in group a in terms of composition. For the hand machining of used and unused brake linings, we therefore reco:arnend that 1. technical measures such as enclosing dust sources and extraction of generated dusts be implemented to keep the concentrations of Chrysotile mic:::-odust under the TRK value, and t.hat 2. persons carrying out the aforesaid activities undergo occupational medical preventive examination according to principle Gl of the industrial accident insurance and industrial safety corporations as follows: - general basic examination - follow-up examinations at extended intervals (three years) - detailed examinations at the usual intervals (five years) For short-term exposure, the indications given in the description of the effects of asbestos dust should be observed. ./. BERLITZ Translations FMSI 06048 3. Group c: Flushing of Brake Drums This group comprises persons who air-flush or otherwise clean brake drums in motor vehicle workshops. Brake linings are also machined to a lesser time degree {less than 10%) The concentrations measured during these activities show very high values a~aging approx. 60 mg/m' during the relatively brief flushing operation::. Ho\vever only sparsely scattered asbestos fibres were found. This does not indicate a zero risk, but the risk is substantially lower than in the hand machining of brake linings. There are indeed indications that far greater concentrations of asbestos fibres are to be found in the flushing of American brake drums. The medical cross-section showed that none of the 53 men carrying out this activity had fibrogenous inhalation effects that were demonstrable to any degree of probability. Only 4 subjects shov;ed suspect findings. Almost no fibrogenous effects were shown in this group by animal experiments. The results of animal studies into carcinogenic risks show that compared \vi th dusts from establishments carrying out the industrial machining and processing of brake lining, the oncogenous properties are very slight. No definite statement can be made however, since the"ltu;nor rate v:as on the border of the anticipated spontaneous tu':lor rate._ The results indicate that the fibrogenous risk is slight. However on the basis of animal tests a minor carcinogenic effect cannot be ruled out at the present time. No assessment of the carcinogenic risk can be ma.de by ascertaining the dust concentration at the workplace owing to a lack of l:AK values for carcinogenic materials. We recommend that 1. the high rnicrodust concentrations sometimes caused by the cleaning of brake dr~~s be minimized by technical precautions; 2. owing to the slight fibrogenous risk involved, no preventive cxc~inations ~~der principle Gl be carried out for the time being; this finding must be reviewed as and when ne,, information on the carcinogenic risk is available; 3. to clarify outstanding questions, - the 53 persons in Group c cross-section be subject to continued medical surveillance, even after leaving their employment; - special investigations be carried out into the causes of the different asbestos contents in the brake drum dusts of German and American vehicles; - continued animal experiments be undertaken to assess the carginogenic risk inference of brake drum dust. .I. BERLITZ Translations FMSI 06049 . '. 4. Wnen appraising the overall results it should be reQembered that tl1e findings of the cross-sectional examination only permit statements with regard to the fibrogenous risk. In the case of inhalation of concentrations of asbestos rnicrodust at the workplace which leads to a fibrogenous risk, a carcinogenic risk must also be assumed. ' BERLITZ Translations FMSI 06050 . ___). ---- - - - - - - - - - - - - - - - - A-b73 fil&ttd!il(Jtq MODEL 1250 NEW! Rmmco BRAI(E ASSEMBLY WASHER Stop blasting dirt-laden air around your shop! Start your brake jobs right; clean brake assemblies with the AMMCO Model 1250 Washer and you'll work faster, easier and cleaner. No need to fight grease, dirt and oil or air-blast clouds of dirty, asbestos-laden air around the shop. One ounce of AMMCO No. 1256 Brake Washer Concentrate mixed with 1 gallon of water makes an efficient, non-toxic, non-flammable cleaning solution that leaves no residue and does not affect rubber, Neoprene or friction material. Discard the solution as easily as soapy water. Just roll the Washer to the job, connect an air line and you're ready to wash. The specially designed gun and nozzle directs a properly atomized stream of cleaning solution where you want it for best results. You can wash and disassemble at the same time. Parts drop into the pan and stay there until they're inspected and re-used or discarded. Solution returns to the sump through perforations in top pan for re-use. r SUGGESTED $14950 DEALER NET Prtcc ,111d -..pPclftcaltons subtpct to rhilnql' w1lhout nohcf' /\-.>J7:l (7-77) Pnnlrd rn liS I\ Rmmcor' mu;;x*''f HfflfflCD TOOLS, INC. i9m!&0 ~ zroo coMMONWEALTH AVENUE NORTH CHICAGO. ILLINOIS 60064 ,\ I , .. \!' - .::1 / No. 1256 Brake Washer Concentrate Carlon of twenty 1 oz. packets. One packet dissolved tn 1 gal. of water cleans many brake assemhhPc: go~ 1 .. per carton. FMS\ 06051 0. BRAKE WASHER ModellW-22 for cars and trucks The safe, convenient, efficient way to clean all brake assemblies - - - - - -/ HANDLE~' II UPPER TRAY Catch-basin and l' ~.~;f:;~;r; I ,:, ;;'f! ,' l-==-"""--..c=,---- Easy to position under perforated-metal parts ~~: each axle with convenient tray prevents loss of I T-handle small parts- height is adjustable __.1!,-;/- ~. : <-::- )''' ~ A COVER Cover closes over solution supply when not in use Cleaning solution is pumped through brush in a controlled flow to wash thoroughly without splashing CASTERS -------- Four large caster wheels roll easily FINISH Ournhle epoxy f1nish resists scratching, rust and corrosion The Kleer-Fio Brake Washer removes asbestos f1ber dust, grease and road dirt from brake assemblies. Kleer-Fio GreasoffTMNo 19 circulates through the brush to clean lhoroughly- yet safely- elimmatmg the dangerous practice of blowing asbestos-laden dust into the a1r. Washing with the Kleer-Fio Brake Washer increases efficiency, too' Each mechanic works at the most comfortable height for him. He works faster with clean parts and avoids delays because parts are held at the axle. where they're easiest to find. And the low center of gravity, caster wheels and T-handle move the un1t easily from wheel to wheel. The solution passes through a barrier filter as it recirculates. FMSI 06052 !;;~----~. . . . . . . . . . . . . . . . . .-"--~ I The Kleer-Fio Brake Wa$herl 1 helps you work faster and safer! ~- I' rt~ ~18! ~ tt ROLLS INTO POSITION quickly, safely-thanks to the T-handle, caster wheels and low center of gravity. HEIGHT ADJUSTS to enable each mechanic to work at best height for him. Reduces fattgue, prevents spilling and loss of small parts. ACCOMODATES LARGE TRUCKS by stmply tf'movolq lhP <tdfust.1ble tr.:ty and usmq tlw hilSf' to r:lltth ~.;nlulron <l!H1 hold p;uts SPECIFICATIONS MACHINE OVERALL Length Width Height Drain Pan Up (Max) Drain Pan Down F G E K J 32" 16" 18' 51" 36" MACHINE INSIDE Length Width Depth M w D 25W' 18" 15 11~,.- WORKING SPACE Length Width Depth Reservoir Depth L w B N 19%" 16" 4swW' ENGINEERING DATA Pump Motor H.P. Fract. Elcc. Requirements 110V.. 60Hz.. 1 Ph. Work Shell Capacity Lbs. ____ 100 _L_b_s________ LIQUID CAPACITY (Machine) Gals. MISCELLANEOUS 6 ---- -----~~---------- Tank Drain Swivol Castors Flow Thru Clonninn nrush ildlustal>le Drilln Pan Shipping Weight. Lbs 110 Lbs. For uso with Kloor-Fio Groasofi'"No. t9 only. Kleer-Fio GreasoWM No. 19 Brake Cleaning Concentrate Specially formulated for use in the Klecr-Fio llrilke Washer. Oilutt~d willt ~ parts of water to 1 part Concentrate. it aids in effective removal of oil, grease. dirt and asbestos fiber dust. The synthetic detergents in this product are bio-degradable. 1-gallon plastic bottle. packed 4 per carton. ""'Wl~!/!1'1'\l!ll!I!BI'IIIIII!!I!'Il!"!c'r"!"l.,,,:O:,.T'.c!'!'c'f':.~,'""!11'3500 KLEER-FLO Washington Avenue South. COMPANY Eden Prairie. Minnesota 55344l!llll!l!l'!!l Phonp 612/941-6710 FMSI 06053 .. . --___.... ... ..--~........ ----------~ . " 32 Proc. roy. Soc. Med. Volume 70 January 1977 ___j I '-.-:.-::..--_.-~........ .::.. --'-~ .' __ .. --.,; -- ~ 1" .-. . .... r:.~. ,s;,-.- rr ; ~: ' ---~- . ..:."":. -::'f' irregular or nodular interstitial opacities of limited extent and intensity on their films. Silica or asbestos exposure had occurred in 22 ~~ of the work force examined. Such exposures had occurred in various job categories in the titanium facility as well as in prior occupations. Eight of the 26 workers with abnormal X-rays had had silica or asbestos.exposure. No clear pattern of restrictive disease in relation to X-ray findings could be seen. Summary and Conclusions Clinically significant or symptomatic pulmonary disease was infrequent in a survey of 207 currently employed production workers in a plant producing titanium dioxide from ilmenite ore. Evidence of airways obstruction was found in 47/~ of all workers (including 38% of workers who had never smoked regularly). This abnormality was not frequently accompanied by disabling shortness of breath. Despite the fact that approximately 90% of the group of workers examined had worked for 2.0 years or more, radiological changes consistent with pneumoconiosis were relatively few. and unrelated. to the respiratory abnormalities observed. We conclude (with the caveats inherent in a prevalence study in which only half of the eligible long-term workers were examined) that occupational exposure associated with titanium production by the sulphate process may commonly cause undesirable irritation of the upper and lower respiratory tract and functional abnormalities of the lung, but does not result in an important incidence of serious occupational lung disease. Individual workers may. however, suffer unwanted abnormalities. These findings, of course, do not speak to the presence or absence of increased risk of malignant pulmonary disease. This is being separately studied. .A.ckno.,.Iedgment: This research study was supported in part by National Institute for Occupational Safety and Health Contract CDC-99-7491. Asbestos Content of Dust Encountered in Brake Maintenance and Repair by A N Rohl PhD, A M Langer PhD, R Klimentidis BA, M S Wolff PhD and I J SelikoiT MD (Emiromnental Sciences Laboratory, Mount Sinai School of Medicine ofthe City Unitersity of New York, NeK' York, NY 10029) Asbestos in Brake Linings The composition of autorqptive brake linings includes chrysotile asb'es:tos,'fibre which comprises about 50 'I~ o'f t.he friclion'.fnaterial. The exposure of garage workers to asbestos during brake lining maintenance and repair has recently been investigated (Rohl eta/. 1976). This important issue was studied because a large labour force is potentially exposed (over one million people in the United States alone). Consequently it was thought essential to determine if chrysotile fibre sunwes braking, and to measure the amounts liberated as an aerosol during maintenance and repair operations. Investigators in the past have expressed doubt as to whether chrysotile fibres can survive the high temperatures generated during braking (L~nch 1968, Hickish & Knight 1970, Hatch 1970). (hrysotile is alleged to be subjected to temperatures in excess of 800C, which would cause i!s thennal transformation to forsterite or to an amorphous magnesium silicate phase. While 'hot ~pots' up to 1000C may be attained (Carroll 1962), the heat distribution is nonuniform, and other processe;, in addition to thermal wear, contribute to degradation of brake linings. For example, abrasion and macroshear may also cause physical breakdown (Bunvell 1957, Mizutani et al. !973). Accordingly, brake lining disintegration by these mechanisms may liberate partially altered or even unaltered chrysotile fibres. ! I i ~ II '' !. ;~ N. -~ .' REFERENCE Miller A, Chuang M & SelikofT I J (1976) Am<rica11 RnieM of Respiratory Di:u:~s 113, Suppl, p 89 (abstract) Analysis ofBrake Drum Dust Initially, ten samples of automobile brake drum. dusts from brake repair shops in New York City were collected and examined by optical microscopy, X-ray diffraction. transmission electron mic- roscopy and energy dispersive X-ray spectroscopy, to determine the presence of chrysotile. Optical microscopy: The detection of chrysotile in brake drum dust by optical microscopy is hindered by the nature of the debris matrix, consisting largely of opaque pyrolyzed phenolic-type resin binders and road dust. Chrysotilc. particularly small fibres, has low optical relief and low biret'nngence, which further hinder its identification. Only in rare instances have large fibres. with optical t6 . ..,.,__--~"--..~~'-- ~~ --....,-----~...,......____,.-~......-:-~-.,....,,.,.."'"":".....-..,.._.,,....,.w~.---~~.~~--- --l{p) FMSI 06054 f .1 ' 1 .,. ...- - -- .....__ ......_--~- ~--- - .. ----..:....,_J:-.---.-...:...... -- ' ____......_.,..- .... ------= __;,-"..'... D, 1)1, 1:, !\rake linings in- rbich comprises d. The exposure .1 ing brake lining 1 i:ently been in:important issue r force is poteni 1 people in the !~ it was thought lie fibre survives :mts liberated as j md repair oper: pressed doubt as 'rurvive the high !braking (Lynch Ilch 1970). Chry.temperatures in 1 1use its thermal t an amorphous hot spots' up to : 1962), the heat her processes, in ,1tribute to dei ample, abrasion physical breakf a/. 1973). Aeration by these 1altered or even ~ile brake drum New York City optical microsion electron micay spectroscopy, otile. ! or chrysotile in copy is hindered 1trix, consisting nolic-type resin ile, particularly md low bi refri n. ntification. Only I es, with optical Section ofOccupational Medicine Table 1 I ClorJ'solilr asbeslos content or brake drum dusl!l X-I'GJ' diffiaciion (step-scan) Na.of MUr~ples Great Britain West Germany .France -United SLates of 8 8 America Finland 1s0 Western Australia 7 No. pusitir.tr 6see I 10 3 4 39 29 I sample possibly positive Weight percent Mean Range 1.8 0.7-2.3 2.4 05-3.2 2.S 4.5 1.8 1.4 .i=2.4 1.1 2.0-IS.I 0.8-2.5 0.~2.3 Transmis.tion electron microscopy No. po.tilir~ 8 8 1 1s0 7 39 33 properties consistent with chrysotile, been obser- onstrated the preservation of crystal structure as ved with this technique. well (Fig 1). X-ray diffractometry: The ten brake dust samples Fibre si::e distribution: In ten brake dusts sampled were analysed by X-ray diffractometry, in both in New York City, free asbesws fibres were sized continuous and step-scan mode. The diagnostic by TEM at magnification 42 000. The results reflection selected for chrysotile (3.66 A; showed that about 80 'l'o of chrysotile is in free fibril hk/=(004)) was step-scanned in the fixed-count form and is shorter than 0.4 11m in length. Over mode. By comparison with external standards, the 57% have lengths of about 0.2 J.lm. At magnifi- amount of chrysotile present can be determined. cation 40 000, such a fibre would be about I em Chrysotile reflections were observed in all samples, long. If lower magnification were used to scan for with weight percentages estimated to range from 2 asbestos, significant numbers of fibres might not be. to 15 (average 4.5). Lead compounds, quartz, detected. carbonate minerals, clays, halite (NaCI), graphite, It is obvious that most fibres are too small to be micas and alpha-iron were also identified in vari- seen by optical microscopy. The Asbestos Stanous --samples~------ ------- - - - ~~- - - - - dard adopted by the Occupational Safety and Twenty-nine additional brake drum dust samp- Health Administration (OSHA) of the US Depart- les were collected by colleagues in four European ment of Labour is limited to optical microscopy countries and Australia. The samples were ob- and neglects to count or control fibres Jess than tained from areas representing variable circum- 5 J.lm long. On the other hand, accumulating stances, such as driving conditions, friction evidence .suggests that such small asbestos fibres material composition. type of automobile and may produce disease (Holt et al. 1964, Davis 1965. climate. The results of X-ray diffraction analyses Pott et al. 1972, Wagner et al. 1973, Hilscher et al. are presented in Table \. Of the 39 total samples 1970. Bouhuys 1975). analysed (including 10 United States samples) Air sampling: Eight personal air samples taken chrysotile was found in 29. or about three-fourths. during brake repair work were selected for electron The mean chrysotile content varied from 1.4 ~~in microscopic analysis. This was done in order to the seven Australian samples to 4.5% in the New positively identify chrysotile in the samples and York City samples. to determine whether a systematic relationship The thermal breakdown product of chrysotile. existed between optically and submicroscopically i.e., forsterite, which might be expected to form as visible fibres for this type of exposure. The memb- a result of recrystallization. was not unambigu- rane filters were ashed in plasma oxygen to elimin- ously detected in any sample. ate organic materials and the residue was prepared Transmission electron microscopy ( TEA,I): In order for electron microscopy by a 'rubout' technique to verify the results of X-ray diffraction analysis. (Nicholson et al. 1971), which comminutes large the brake dust samples were prepared for electron chrysotile fibre bundles into individual fibres and microscopic analysis by means of a technique fibrils. Large inorganic particles are likewise re- which disperses the dust particles in a nitrocel- duced in size. permitting all chrysotile to be seen lulose film without allering panicle sizes. Both free and JTieasured. Chrysotile was identified in the chrysotile fibre bundles and fibrils were observed eight samples, in both fibre and fibril form (Fig 2). in all 39 samples. Most of the chrysotile retained its characteristic morphology without significant Bv measurine a large number of fibres at maenilic~tion 42 000 and ~onverting the \'Olumetric-data alteration, and sdccted area elc<.:tron ditfraction into mass. a concentration per volume of air is patterns obtained on representative fibres dem- determined. Comparison of optical micro:.copic I FMSI 06055 l. ___ _ .._...---------------~----~~>rt ----~~~~-------w----~---6 --!:": j. i 34 Proc. ro)'. Soc. Med. Volume 70January 1977 .. fibre counts and the electron microscopic asbestos taxi fleet repair shops and a municipal truck repair mass calculations indicates that a positive cor- shop in New York City. Air sampling and analyti- relation exists between the two sets of data. These cal methods for the determination of fibre con- results show !Jtat the standard (OSHA) optical centrations were in accordance with the OSHA fibre counts may be only indicative of the total techniques (Bayer eta/. 1975). Present regula)ions asbestos exposure. of OSHA prohibit asbestos concentrations of 5 fibres per millilitre (f/ml) or greater, longer than Asbestos Exposure of Workmen 5 11m as a time-weighted average, and con- After the identification of chrysotile in the brake centrations above 2 f}ml will be illegal after July drum dusts. asbestos fibre exposure during main- 1976. Peak concentrations or maximum excursions tenance and repair was determined by personal air of 10 f,mJ are permiued by the regulations. sampling carried out at auto~obile repair shops, In brake lining inspection and repair, the wheel is removed from manly removed fr means of a jet of garages in Baltin shown that this is the shops (Cast! situation exists ir Table 2 show that the breathing zor pressed air blowi gradient, diminisl:i from the operatio to 22m from sud able concentratim t.:, -~ ---. -;_ .. I I I I ...~ ...., - : --~--: I .. - ..:.... ~ .;-:-::... I A ;- .. .;,,::::. ---~ ..~-- . i' ~:j J.,;) --\n -i ; ~- 4 . ~~--~:. Fig I ftcrmn plwromicrnyraplr.< ~fhral.:< drum du.<ls. taken arrariou.< mu.<Jnificarion.<. A. tire numerou.f ch~_notilejibrils '"'!I<'han ur.-ru_q<" ftn.<llh of U.-1 pm or /('.H ( x j(} (}()()). R.lur_q<'llllllrha.\ of drry.<olih!ihn.l imhl'thhd irr. utrd pmlrudirr_qfrom, "f'"'l"'' partid<'. prohuh/1 prroli:<'<l plrttwlic re.irr himhr ( x 30 IJ/1()). r. cbry.wrih lihr<' hrmdt.. ( x -15 UIJ/1}. o, lurgl' particle in lc:f! cemrc vj plruloyrupll i.r tilt! >utll<' a> irr c. hut cunrrOI h<' id<'llli/lt'd arlo11 mu_qll[/lcaliun ( x 54(}()) Fig 2 /cctron phol u.uudalt:d "itlr opu~ - .... :.;. .------~~- --:r------~-----~~~---~- .. . . . .'--~--~--~-._--.---;:--.........-r------- FMSI 06056 'I --.~ - ................ _ _.....t...__----...,:-- ____ ___...a...,.,_ ---. - ~- __ ..,______ .. _____.___ -~--=-~ -I. (truek repair : and analytiof fibre con1 the OSHA at. regulaJions trations of 5 , longer than :, and con;al after July ,m excursions lions. air, the wheel Section ofOccupa~ional Medicine 3S is remt>ved from the axle and loose dust is commonly removed from the drum and back plates by means of a jet of compressed air. A survey of 220 garages in Baltimore and Washington. DC has shown that this is the method of choice in 80 ~~of the shops (Castleman er al. 1975). A similar "Situation exists in New York City. The data in Table 2 show that fibre concentrations are high in the breathing zone of the operator during compressed air blowing. An asbestos concentration gradient, diminishing with time and distance away from the operation. appears to occur. Persons up to 22 m from such activity are exposed to measurable concentrations of asbestos. Personal air sampling was also conducted at New York City Department of Sanitation where truck brakes are repaired. Used linings are 5alvaged by machine grinding to remove: dirt and grease from the surface. New linings are bevelled by grinding to reduce noise and improve break-in. Accordingly. these studies relate to levels of asbestos exposure which may be experienced by workers engaged in brake lining manufacturing. Table 2 shows that fibre concentrations experit:nced during grinding ranged from 1.7 to 7.0 f;ml of air in the breathing zone of the operator. The: background or area samples for this operation ranged from 1.2 to 0.2 f;ml, with a general decrease .. ;;-.) ~~::-:- ..~ .....;-1 -"7 ~- :..!;: "i~-- .. ~ ,_..~.~I.;~-,_ ..._,._ chry.wrile fil>rils protruclit(q from. 45 IHHI). D. /ur<1~ 54UU) . Fig 2 Eleclron p/wromicroqraph.t of pcrwnal air .wmpkt IDk<'n durinq hrake rtpair work. Clumps of chrysotilt art auaciar!dwirh opaque particles of road dusr ar~d re1in bir~dcrs. A. B. x 6U UIJO. c. o, x 72 ()(}() -. ~ r- ......~-----------~----- --~~-------~.,.,....,----- _ __,.,.----.___,_ - - - - - - - - - - - t I FMSI 06057 !I I . ______------~--~%~'~'~~<~,A~-----~~-------~--------~~a--------~\a_ ~c~l~-~--------~--- 36 Proc. roy. Soc. Med. Volume 70 January 1977 Tablt2 Penoaal air ,..mpl.s, oulomobile and truck brako repair AuiOmobilt brake rtpair Blowing dust from brake drums: Distance 1-1.5 m Distance 1.5-3 m Distance 3--6 m Background (5 min after air jet blowing. distance 3.6-16 m) Background (7-14 min after air jet blowing. dist.ance 19.6-22.6 m) P~ok fibTt conc~nlraliDII No. of (fibrts ~r ml) SDmples Me1111 RAn~ 4 15.0 3 3.3 2 1.6 2 0.2 2 0.1 6.6-29.4 2.0--4.2 0.3-U O.HI.2 0.1 13 Truck brakt repair Renc-..ing used lining by grinding (dist.ancc 1-1.5 m) 10 4.8 1.7-7.0 Background to grinding used linings: Distance 3.3 m 2 1.5 1.2-1.7 Distance 8.3 m 2 O.B 0.6-1.0 Di5tance 20.0 m . I 0.2 Bevelling new linings 4 37.3 23.7-720 Background to bevelling new liniDgs: Distance 24 m I 0.6 Distance 3.6 m 2 0.4 0.3-(J.S Distance 9.1 m I 0.3 23 away from the operator. From six to ten other mechanics work within an area up to 20 m from this operation are exposed to asbestos as well. Since a person breathes about one cubic metre of air an hour. multiplication of the fibre concentrations by one million gives the number of fibres inhaled during this period. Fibre con- centrations measured during bevelling of truck linings were as high as 72 f:rnl and averaged about 37 firnl. Background counts were measured up to 9.1 m away from this operation (0.3 fiml). Fibre concentrations measured during drilling holes for rivets and grinding ranged from 0.3 to 29.2 f,'ml. as reponed by Boillat & Lob (1973). Four of the nine values exceeded 5 f/ml. Conclusions The existence of significant exposure during brake servicing operations necessitates the following measures: ledge support under a grant from the National Institute of Environmental Health Sciences, ES 00928 and support by the Ford Motor Company. MSW wishes to acknowledge support under a post-doctoral fellowship from the NIEHS, ES 02565. We are grateful to the following for assistance in obtaining brake dust samples: Professor Donald Bowes. University of Glasgow, Scotland; Mr L B Bowes. Departmeni of Labour and Industry, Adelaide, South Australia; Dr Trevor Turner, Adelaide, South Australia; Professor Jean Bignon, Hospital Laennec, Paris. France; Maunu Harme, Geological Survey of Finland. Otaniemi, Finland; Dr G. Gaal, Helsinki University of Technology, Helsinki, Finland; Dr K Robock and Dr W Klosterkotter. Institut fiir Hygiene und Arbeitsmcdizin des Klinikum der Universitat Essen, West Germany. (I) Implementation of industrial hygiene procedures to control exposure. (2) Clinical studies of garage mechanics to determine evidence of asbestos-related disease. (3) Epidemiological studies of the mortality experience of exposed workers. In addition, the entire variety of dusts and other materials present in brake repair work should be characterized in order to determine its disease potential, especially silica and lead compounds. .Acknon-ledgn~tnt: The authors wish to acknow- REFERENCES BayerS G. Bro,.n T A & Zumwalde R D (1975) Document TR-M4. US Public Health Service. Cincinnati, Ohio Boillat !\t A & Lob 1\1 (1973) SdiH:ei=eri.sche mt>Ji=inisch~ Jt'ochen.schrifr103.. 39 Bouhuu A ( 1915).Annal of Internal M~dicine 83. 898 Bo"'eiiJT (1957) W~ar l. 119 CarroiiWG (1962) Briri.<h P/a.<tirs35,414 Ca.tlrman B. Camarota LA, Frilsch A J, Mazzoccbl S 4 Cra"l~,- RG (1975) Pu/olic Hcalth R~poru 90. 254 DnisJ M J ( 1965) Annal of lh~ N~-.. York A cad~m; of Sci~nus 132, 98 HaldiD ( 1970) An""& f0C<1'fhJ Hicl.i.Jt D E .l Kai~hl K (1970) Anno/ufOaupu Hil.chn W.Stchi S, Frio (1970) .\"aru...u....,JChar Holt P F. !\liBs J & , ..,. ( 191>4) JourNJIof PathO: LyDO:bJ R (1968) JourNJIfth~ Av !\lizutani \, Obra H &. (1973) ll"~ar D. 3S7 .Nicbolsoa W J, R ohl A ~ (1971) In: PI"DCCCding Con~rcss. Ed. H "' En!= New York: P9 H6-139 Pon F. HutbF &. Friedr (1972) Zenlru6liJ:tjiir L Robl A IIi, l.M:ff A !\1, (1976) Enrir.,.,..ntol R< c,w.~...,r J ~- G & (1973) Briti.Jh.knunol oj Neurotoxic Pr Certain Aliph: by Peter S Spencer and Herbert H Sd (Departments of p, Saul R Korry Dept Rose F Kermedy C. Albert Einsltin Co1 Bronx, Nnr l'ork, During the summt ipheral nc:uropatt group of employf plant in Ohio, m disease was chara( sensory loss symm the feet (ADen et affected individual ment where colou solvents, were apJ coated fabrics. F process required tl containing methylc isobutylkctone (I (MBK) wasgradu: 1972 to replace tho was in its maximal first case of peri ph tly thereafter. Tht into the printing d with other isolate individuals chron gested that this cm ties. MBK produ ---------.......--..--- --- --~- ---;-~- ~-----~---- FMSI 06058 .... . _- : :. . .:.:. . ___-------=------- .-----_____...,___46-_,._.__ , ___......,...___ . _.-.....i.,__ --~~~-------~ _.I the National Sciences, ES or Company. )Ort under a ~e NIEHS. r assistance in essor Donald land;'Mr L B 1dustry, Adelrurner, AdelJean Bignon, aunu Harme, emi, Finland; r Technology, and Dr W 1d Arbeitsme- Essen, West cvice, Cincinnati. if! 103.39 tocchiS & MUS 132,98 Ha1c:loD (1970) Annals of Onupalio11al Hygi~n 13, 2S Hltkl>.h D E & Kni~hl K L (1970) Annal.<o}'Oaupuli"'"'l Hrt~itmIJ. 17 HilscMr \\',Sethi S, Friedrichs 1.: II & Poll F (1970) Nalumi>.<L'II.Idza/1<'11 57. 356 Holt P FoMills J & Yo.ung D K (1964) Journal of Pathology und Bucleriology 81, IS L)'Ddl J R (1968) Journal oflhe Air Pol/u1ion C"ntrol As.<odalion 18,824 Mizutanl \',Obara H & :>;akajima K (1973) Wear ZJ. 381. Nicholson W J, Rohl AN & Ferraud E F (1971) In: Proceedings of the Second International Clean Air Congress. Ed. H_ M England & W T Berry. Academic Press. New York; pp 13&-139 Pon F, Hulh F & Fri<'lirichs K H (1972) Zelllralblalljiir Bukl<riulo.<lie. Abt. I. Originale. 155. 463 Rohl AN, Langer AM, Wolff M S & Weisman I (1976) En<ironmeniUI Re.<earclr 12. 110 WaJ:Iler J C, Berry G & Timbrel! V (1973) Brilish Journal of Cancer 28, 173 Neurotoxic Properties of Certain Aliphatic Hexacarbons by Peter S Spencer PhD and Herbert H Schaumburg MD (Departmell/s of Pathology and Neuroscience, Saul R Korey Department ofNeurology, Rose F Kennedy Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA) Section ofOccupational Medicine 37 several species of experimental animal (D~ckeu et al. 1974, Mendell et al. 1974, Spencer, Schaumburg, Raleigh & Terhaar 1975). These studies demonstrated that prolonged intoxication by inhalation or subcutaneous injection caused the insidious development of symmetrical weakness first in the hindlimbs and later in the forelimbs. The first signs of peripheral neuropathy developed after 4 to 12 weeks of continuous inhalation of 20(}600 parts/106 ofMBK, and after 12 to 16 weeks of intermittent inhalation of 1300 parts/10 of M BK. The onset of MBK neuropathy was associated with a reduction in the sciatic nerve conduction velocity (Mendell et a/. 1974), an indication of nerve damage also found in rats and monkeys inhaling 1000 or 100 parts;I0 MBK intermittently for periods of 3 and 8 months respectively (Johnson 1975), the figure of 100 parts/106 being the recommended Threshold Limit Value in the United States. Recent studies have suggested that concurrent exposure to MEK and MBK will produce neuropathy more rapidly than in animals exposed to MBK alone (Saida e1 a/. I976). Methylethylketone alone or MBK alone produce no neurotoxic effects (Spencer & Schaumburg 1976). The purpose of the present paper is to emphasize the importance of chronic testing of potentially neurotoxic compounds in experimental animals. to describe the range of hexacarbon compounds which have been identified as neurotoxic al!ents and, finally, to characterize and illustrat; the pathological basis for the onset of the nervous system disease. A total of seven hexacarbon compounds have been tested in this study (Table 1). During the summer of 1973 an outbreak of per-. ipheral neuropathy developed among a large . Table 1 group of employees of a fabric manufacturing _H_e_,a_c_ar_bo_n_c_o_m__:p_o_un_d_s_res_r_._.t _ _ _ _ _ _ _ _ __ plant in Ohio, USA (Billmaier et a/. 1974). The disease was characterized by distal weakness and sensory loss symmetrically in both the hands and the feet (Allen e1 a/. 1975). The most severely affected individuals worked in the printing department where colouring inks, dissolved in volatile (I l nhexane CH,CH~CH,CH,CH~CH, !2) methyl-n-butylketone CH,COCH~CH,CH,CH, {J) ~.5heAan<dione CH,COCH,CH,COCH., (oil 2.5-hexancdiol CH,CHOH!CH,l,CHOHCH, (5) ~.4-h<xanedione CH ,COCH ,COCH,CH, (6) ~.3-hexanedione CH ,COCOCH ~CH,CH, {7) 1.6-hexanediol HOCH,CH,CH,CH,CH,CH,OH solvents, were applied to the surfaces of plastic coated fabrics. For several years the printing The first compound, 11-hexane, an important sol- process required the use of a 9: I solvent mixture vent and a minor component of petrol, was indicted containing methylethylketone (M EK) and methyl- in several reports as a possible neurotoxic agent isobutylketone (M IBK ). Methyl-n-butylketone (Herskowitz et a/. 1971. Korobkin et a/. 1975). (MBK) was gr<.~dually introduced in the summer of Rats were exposed continuously to atmospheric 1972 to replace the M IBK. Methyl-n-butylkctone levels of 400 to 600 parts! Io of 11-h.exane for up to was in its maximal use by December 197::! and the five months, 500 parts1 10" being the US Threshold first case of peripheral neuropathy occurred shor- Limit Value for 11-hexane (see also Schaumburg & tly thereafter. The recent introduction or MBK Spencer 1976). The second compound. mcthyl-11- into the printing department of the plant. coupled butylketonc. the solvent implicated in the outbreak with other isolated outbreaks of neuropathy in of neuropathy. was administered to cats by sub- individuals chronically exposed to M BK. sug- cutaneous injection of 150 mg,kg twice daily for gested that this compound had neurotoxic proper- periods up to six months (se<' also Spencer & ties. Mf!K pro~uced peripheral neuropathy in Schaumburg 1976). The third compound, 2.5- . ---.. --~-~ -_____ ,_.-r,------~ --...-. ------ -----'.- -......,.....--. -., -------- -- FMSI 06059 ., " qI I. II .I,I I, il '! I' i , ~~ ~--...:.:.:-.: ' -~ ... \ __)-. ~--~~-- _' :~:- ~. ( '"" -r'. ; -\ / 7 ...-:> ...... .: '.. ~'-' . .-- ..:.....-_z.:.-....... -~~ --. '.\ ,....:...... . -. .. -~ ..... __ -.-:;::::.:_ ..... . -.',. --~.-~- .-.."":. ~-> ' ~.:_.:-' ---..::.:-:~........:.. ~-- -~ '- . t_ -~ ~ '0.2J.Lm Fig. 7. Atmospheri.: o;ample coiJ~t.:d 0.8 m ahove ground level at the exit of Tullamarine Freeway. FMSI 06060 Airborne asbestos in the: 'icinity or a frc-e"a;> . . '~--.~- >l I I .: ..-.r._-;, ~<: i ~~ ~., _, ... '!;'... 5ll7 Fig. 5. Atmospheric sample: collected 0.8 m above: ground level at '.lclbourne Uni>-crsity. /1..' '1):0. 11 l l (:Ji ) t i __ ______!.' FMSI 06061 ----~------~------------~------------------~-------~-' 0.5J.Lm L---.1 ~ (; 1~' Fig. 3. Dust sample from worn brake lining. FMSI 06062 Airborn~ asb<!stos in the 'icinity of a fr~c"J.! 585 r------ . I f \..._.,.---- t t ! r I I' I ~ f I ! l f.... - Fig. 2. DitTraction pattern from :)ample: in F':?- l l I I I ! I I but would be expected to be very much lower under normal city driving. Chrysotile has been shown to maintain its crystal structure until temperatures in excess of .">00 K are reach..:d (Yada. 1971; Robock ::~...: :.:!.),:~~:.;,J':~r. 1973\. T::~ observations on the worn b:<1k~ dwms an: then consistent with the likdy tt:mpt:ratur.:s re~1chcd and the known thermal bchavio.tr of ch:~sotilc. Yacl:J. (196-:'. llJ71) has shown that ekctron bomb;1rdment inside tho:: ~kctron microscope C<::l k:d :,> r~oJuction of .. OJ:orphuus matcri;!l in tht: f1hrL's ~tnC. th~rt.:for~. cxc..:s;). \~ ~xposurt: during t:xam.. :n.:tion s!-. )Uld b.: a\oic!.:J. Table 1 .:~:.::) ... ; 4i1f:~!; :\lr .:!E.,':IV~ik and br~\k.;. ii1~ings. nmx 10_, \"a I-..~, r~...lr ..chr: -.~'ti\: IY Jc!.l. ~ ._ ' - : 'i~ II - -~II ..:.:"1) .;_:o 3.65 2.71J ~ f>l) 2.51 2.4.3 : :;u : :5 2.15 t.~2 i.~l) '. ..!:1 -:.~ l =' F~.:<: br:tkc !:~:::; - .~ I ~ ~ ..:'\ J.6~ ~-6~ ~-5~ 2.-15 '" - ;_, l !l) :..! l ~.::: ; .::! \Vorn brake lining i.~ I -l.hO .'.67 2.67 2.56 2.-17 2 ~A 2.10 1 15 1.55 I ~'-' I I'J P!an~ (Mil (001) (110) (0201 (llt12i (:?01)) ( 1:;n) (~lll) [00.1) t22DJ (0-111) {2t l~ 1 11''-11 (11'111 I:; 'Ill tll!l)) t-l.!l\ll lilt; II Samples taken eit.1er on the roof or at ground level near the Departmen! of Industrial Science contained very low concentrations of asbestos fibres (Fig. 5). Although the ring; in the diffraction pattern (Fig. 6) '-!re r.or<: di~Js~ ::-.,n from fresh linings the i:~to::r pl:.lnar sp;tcir::;s. '~--:.,n in Tabh: :2. again match ~oth the values for fr~sh linings and Yac!a's vah:~s. .-\!though tho.: co:n;x:rison in Table 2 <:nabkd the presence of asbestos to b.: deduccd. no attempt was mo.c!e t( ~'':m:1t-: t';; atrr_._,,phcric conccntration b.:caus~ of its \cry low uluc. S:1mpks tak.:~ o.: the exit frl'I11 thc fr.:.:way. how- ~\~r. cont~t!r:....:..; ~~ r:1.tch hi~h~r cont-.:..:ntration of asbestos p;tr:::k; t; ::;,;. 7 and ~) cstim:lt..:d ;\l an ;m:r;tgc of 5 x 1\); pan:cks m- 3 over the 9 h sampling r--~ri-..Jd. Th..: ~cn,:r:~: ~q~;:L-~lrancc of tht.: fibrt: cht5tc:rs ~uh.l ~:i..: pre;, .::~ ..:: ~,..- ~,.1~!:.:-r :n:H:..:rial i:' vt:ry sitni!:~i to tha~ .>:--..:!"\...:...: , - :.-.: \',orn hr~tkc: lining. L:u~t. :\~~~~n th-.: l:itrr~:..:t:~)n :'. .".:-..:n1~ tit."' ll\.-'l sho\\ ~ignit:.:a~~ amounts oi ~.mcrr :'-t~"> mat..:ri:tl and ma~c:h Y:~d~\s .alu~' ITabk ~). T;tb~c , Valu~s of .i(llkl) for dlnS('tik and ;tirbc>rn~ ~~~:-,.:.;.~o'-. nm x til- 1 Valu.._., fl.,r chr}"'<.k ''1 .tJ~t. : \)\.- 1 -! ' tilt.. I! Dcpt. hdlh~ri,d S..:i~m;l! Tu\lam~~=-:!1~ fr<:('\\ ~~ :-- t:"'\ it 1.2 1 1 1 ' It - - - - - - - - - - - - -~ FMS\ 06063 J. ALsn. D. WATS0:-1 and J. B"GG t:XPt:RI;\IF.:"T.\L .\ numl:r ,,r m..:th,,ds have h~..:n proposed for the esti m.:tttm of ~sh~~tos parli~ks in the .atmosphere (Kc~flan ..::J Kupd. 196S; Lane t'llll.. 196:;; Gadsden <'I ul.. 1970) h"' ;1t th~ pr~s~r.t time th.: only method of sullicicnt scnsi- tilitv and sdecti,itv for the vcrv low concentrations in '":v::d is the clc.:tr~n microscopy of samph:s colh:ct<:d on s.:ot.Lc'l.: IHt~rs. Atmo;phcric sampl..:s were collected on a :1-!i:lipor.: niter (\'SWP 0-l7. 0.0~5 1:m pore dia.) at an a>era~~ rlow rate of 0.6 I min- 1 A High-Volume sampler was ~1\>Jiii~d by pl;lcing an aluminium fac.:plate containing a ;mal! lub.: over the inlet I<> th.: sampkr. A Millipor~ ::::~r holc:r was connected by a plastic tub.: with a rota~:~ in :crpos.:d to th.: small tube on the face plate. s~rnpks w.:;c taken at thr~-c loc;1tions. {i) on the roof of tl:.: D.:partmcnt of Industrial Sci.:ncc. University of Mclbot~rn.:. 10m ;1bove street.levd and 30m from the nearest :r~i1k. Iii) outside the same building 0.8 m abO\e street bd. (iii) at the c:tit of th~ S.E. end of the Tuilam:1rin.: f;.:cway. O.S m above ground level. This last sampling point "" 50 m irom the position wh.:re br:1kes w.:re applied :o r~duc~ the speed of \'Chicles from approx. 100 to 60 i.;m h- '. The total number of vehicles passing all three lo;;Jtions during the total sampling period was wry similar .tnd the mujor dilfo:rcn.:o: was the absence. loc.'ltions (i and i:). or presence. Location (iii). of cxt.:nsivc braking. The s"mp!ing p.:riod was from OX.:00-17:00 h during ~ov.:mb.:r 1973; the weather was fine with only light winds o'~r this p;;riod. After tho: samrl.:s had been collected the ~t:!:iporc filters "ere coated with a carbon film, appro~. :o nm thickn~ss. and then five smilll pieces (1.5 x 1.5 mr:>) cu; out at random. Each small section was placed o~. a copp~r grid. carbon film facing down. and the mem- bran.? materia! removed by dissolution in acetone. Electron micrographs and c!iffraction patterns were obtained trom t!:~s~ sp~cirr.cns using a Phillips E~l ::!00 microscope at ~u kV. The e:~ctron diffraction patterns were calibrated by evaporating aluminium on to the copper grid and by comparison in:erplanar spacings. d(lokl). could be deter- rnir.ed. Samples of fresh and worn brake drum linings were obtained from an automobile repair shop and wen: crushed g:r:tly in a mortar and pestle with a few ml of chloroform. An electron microscope grid covered with a smooth film of evaporated carbon was th~n dipped into this suspension and the chloroform allowed to evaporate. RESULTS A:"D DISCUSSIO:'O Figures and 2 show electron micrographs and diffraction patterns from a sample prepared from a fresh bra:.c lining. The characteristic structure of chrysotih: asbestos, long filaments each of which is a hollow cylinder (McCrone and Dclly, 1973). is clearly visible in this micrograph. The electron diffraction patterns of chrysotile have been d:termined and ir:d~~cd by Yada (1967, 1971). I: Table I the interplanar spacings determined from the pattern of fresh brake linings are compared to Yada's values and the agreement i;; :;een to be e~ccllent. Figures 3 and 4 show results for the dust from worn brake linings. T~e average length appears to be shorter than in the fresh lining but the hollow cylindrical structur~ is still obvious. The diffraction pattern still consists of well-defined rings and the interplnnar spacings derived from these rings are in good agree ment with Yada's values (see Table 1). There was no indication from the diffraction pattern of the presence or forsterite. the name given to therma]iy-degraded asbestos. It appears that for the wear this lining had received no significant changes in the cr}stal structure due to excessive heating had taken place. Tempera- tures within brake drums may reach S73 K under racing conditions with severe and repeated braking 0.1 J-Lm : ,__ '\\ . "'_l \ ').~4 \ \" ',- '.. -....~. .,.... -----~--------..._\_;~ L.:-! FMSI 06064 _ , _ ,____.._.,_ _ASB...E....S.'T.""c"")~S~I.,-N!':!?~'~'t5"'~~n!\~i""A,..i1""\J,i<llt"'i'f~<~~~O~G;I!A,n;;t~lll.OJ.)tl-------------...____----- -- ---- fL ( c.t'-\1 (t'17fo \1745 Suite SJ0e9!!,eCrsroyns\aOlaVSlqSuHa;wey4. s+~ VT j Arlington, Va. 222~ - - - ______ AIRBORNE ASBESTOS IN THE VICINITY OF A FREEWAY l ALsn. D. WATscii-;t and J BAGG De;>ar!m~nt of Industrial Science, Unhersity of M~l'oourne. Parkville. Victoria 3052. Australia (firs! rec~ic~d :!2 Decnnher 1975 """ iu jinul F~rm 16 fel>rrfllf}' 1976) Ab$\r:lct-A;bes:os fibres taken from iresh or worn brake linings or collected from th.: atmosphcn: near a fre:="ay ".~>ere ~:t.amin.:d by ele-ron microscopy and electron diffraction. The major eiT.:ct of braking ap~rs to b... in separating bunches of fibres and reducing their a\erage length but not in altering th:ir crystal structure. The suggestion that grcss chang.::. in the _crystal structure are 1:-rou:;ht about by he~t gen"rat.:d during braking is r:ot supported by this work. Airborn<! samples were: co!kctod at points where th.:re was con~iJ.::rable brakir.g and where therl! \\as only sli~!\1 l'r.tking. At th~ rL'int y;hc:re sli~ht tlraking took place the airborn.:: con;:.:ntr:uion was ~cry lo" anJ could not b~ >ati>:Ctcttt il~ measur~c. Ai the point "here considcr:~ble br:J.king occurred an estimate of S x IU' m > r:tnick,; was d~termi~ed. ~:J.ch ?article consisting of :J. sm:tll bundk of fibrc:s. The majority of rarti.;!.:s had a maximum lin~r dimension .;;2 Jtm. t:o-TRODL'CTIO:"' The concentration of asbestos fibres in the atmosphere may r.:ach h:gh levds in the immediate vicinity of mining th,; asbestos mineral or manufacturing asb-estos products. It has be:::n known for a long time that the inhabtion of fibres at these concentrations is injurious to both man and animals (Merewether, 19301. A quali;;lti>e s~tndard which has be:.:n pro- posed by th.: E.P.A. LVl'ws Futlrs. 1973) is th.tl t;,:.:r.: should be no .isibh: .:missions during the h:mcling and manuf<!l:l-~c of asb.::;tos products. One criterion for a rcc.:orr:m.::1J:d quantit:Hive stand;ud is that th<! co~~~ntration ~houk1 not e.,cced 5 x 10" fibres m- 3 of kngth :::; 5 pm for a 30 y exposure and :h;tt this stanJard shot.:!d become mor~ rigorous af:.:r July !-)-(, h..:comir.; :2 x l(l'' fihr.:; m- 3 !~IOSH. lJ72; LS Dept. L.,c.,.,_ :<J~.:'I. British ;tnc.l \\',;,t German r:-oru~.a!s .t;;r -.: \\ nh th~ n1ur~ ri=urous stanJ.ard suggc~;c:c.l ;ti1u'.c- :-o~:-.c:~i ;!!lJ \\\litowitz. 1973). E.~t.:nsive \\Ork bs bc:cr-. c::rr;~J out on the ho:;t\th of work..:rs t:.\roseJ in the in..!:t>:ri~o-,; protiu..:ing airborne asbestos. \1uch k;s \\Ork ~.as been c.:arncJ tlUl on the prcs.:nce of asbt:stos in .h:..: .J ~mosph~r.:: f:tr :t'"ay from iJ.n: such 1:1Ju-;try. .-\sr -<JS ":lS found in al\ samr12S t:~en irom th..: atmc:<:.:r:.: of S<:\t:C.tl <:iti..:s in Euror..: "hid1 diJ have ;m "'')-;,tos ir.Liu:.try tHolt anc.l Young. 1973). Th:: asbestos\'"' pr.:~.:nt chid1;. as sing\.~ fihr.:s but t >m;~ll fraction occurred :1s agglomt:rat.:s. :---:o 4'.l:tnti- LJ.ti\(.! e~tirn~~.: \..,f corn.:\!ntr:.ttl ...H1. \.'f.:lS m:.u.h: jut t:01n~ r . ::-:J tO ot:..::- ,.1,:-..:nJ..;J \',\rllcu!.lh.:"' It V..lS smatl Pr..:hn\1:1:::-:- ~ ..:-.._.:h :""r :"\.'.1. y,_,,.~ (It; ...:~~)'.'-<:L! con- t-'.:n~r:tti\,:~:- : .. :1:;1:1_:! f.-1):~1 ! i t'"' <'1 1 ng m J \\ 1th ..!urL- ~- - - - - - - - - - - - - - - - j.'~r!. \' t....;.~._ :.; \ ._, ,:1 .. ::.:. ; P~:.:-..::1~ .. .:.~: ..--..) C S I~ 0. u~-.!:-ll_,n t'i Tr. -.\~;-:;;~'1'-' \\!..::;,~,Jrr..:-. _,t:-:..:.~:.!. cate sampks differing by a factor of ~--3 (Selikotl 1972: Nichol:>on rr al.. 1973). Asbestos was <tlso found :moto be pr~ent in all samples taken from the atmos- phere of 49 cities in the U.S.A. (SelikofT. 1972). The source of asbestos emissions in the abst:nce of asbestos mining and industry i~ n matta of spccut!tion but one ~trong possibility is from thc br;tkt: linings of automobiks. The~c linings arc suhjL-ct:u to consid~rabk w~ar kading to the r..:lt::tsc: of asb.:sto,; dust. In on.: c;tr.:ful stttc.ly th.: rcle<t:it: of asbL-..:us was measur..:d by surrounding the {lr;tk.: c.lru111 witl: a cu!- kctor anc.l capturing th.: total .:mi~sion (Jac.:ku t'/ uL 197::;). t\ tot~tl t:tllission of 17.!\ Jig_ kill. I ror [';!SSL'Il);L"r vchidcs ;md 5-t::; Jrg km- 1 tra~dkd lor light truc.:ks w.:r.: quot.;:d as typical valu.:s. Not all this cmissil'n rca..:h.:c.l th..: atmo~ph~.rc. som.: <ki'Ositing urt'll th.: grounrJ :.ttHJ S\.1tll~ Pl"in~ r~t:tint:d b~ tlh.~ hrai..~ dnnn. Tht: fr~u.:ti,Jn \\hi\.:h b~~:tn1l: airb~.,rn~ \\:t'-' \.''ti:1~~~~~d tO b..: ).7';" f,_,r rt"'=-'~-n~L'r V~h\d..:s ~ti\J 2."-J'',. r~'l' lrtH.:~:->. This r~,~~trc'J :\:,,, l:!a,..: the t:.\r~ct.:d rcsult th~tt ltc:l\y br;d,:ing pruJu~\!d llll'fl! ctnlss\\.)11 than \i~hl h:-~d,i:lf. Altbou:;h it is \'er) ditlicult tL' t:llll\~rl tlt.:s..: rcslt!ts into atmo,ph~ric CO!hXnlr:lliorl'i L'\c,\d:- t>nly \cry'-'"' :oncentrations would h.: :Jn!i..:irat.:c.l. L)nt:h ( 19(>~) c.\.amin.:d thL' dust l'rt>ta br;J!.,~. li1tin~s :tnd from th-: appcaran.:~ ,,f th..: libr~s su~~c,t..:d t!:::t the C.:r) >t:tl S!rlll:turc of the librc \\ .lS Cc':,!l~td-.:J \'~ !11::\t rdc:h~..! Jctrin~ hr:tl..in~. !Jolt and Ylltlll):! ( 1'1~ 31 fount! th:tt fibrc> C<llk.:t.:J by them !'rom tlt.: a!llh" p!1..:rc ,;ho-.,-:J \<!f) liuk c'idcn..:..: of lt>ss ,,f cr)>!:tl- bni !~ . . :~~~: tlh:r("rPr.:_ fr,Hl)\\ tn; I.~ ~'(h s 'U~.Sl.''t:\,'!t. l:l'!l--~... ::~...: ::-,~t bt.li!t~::l:; n1~th.:n:1b ''-'-'!L" .t t~h''"--' !ih~..!_, '~~If-..':.:~\.:\ ~'f.\~1.. lj;';!)~'- 1'1\1...' ~!!:1~ \...f th~ \\1..""~:~ rq"~l'!h:d h.:: ..:\\ . \' t~ ..,:t::Hn.. n~ui ... ....-il) ..... :_. tlh.: P"-h... ihk: \..\\;\!td"tt!:~'ll th~:t t"'l:~k;.. h~ in.~....., (,_;\: :\1,!.,.._ l\l t!t ..: ~~'~';,. '-..h'' .'\'':~.._pl:.!:.'t'il Ll ~ FMSI 06065 Airborne asb-estos in the vicinity of a freeway 5S9 The particles consistd of small bundles of fibres together with other material which may have contained binder present in brake linings. Another pi)S.V ibk source for this amorphous m:lterial consist~:nt with a location wh.:re braking occum:d is w.:::~r from tyrcs. Me::~sur~ments by other workers- (Pi<!rson and Brachaczk. 1975} h;we sho'-'"n concentratior.s of airborne debris from tyre wear from 0.05 to 2.2 pg m -l. The number of fibres in the bundl;; and th::ir size varied considerably and no attempt was made to count inuividual number of fibre:>. The m:~jority of bundles did have a maximum dimension ~ 2 }tffi. Although these results are limited and of a preli:ninary r.:~tur~ the following point:> can be mJde: (i) Electron ditTraction has proved to be ~- method of great sensitivity in the identification of asbestos partic!.:s suitable for the low concentrations found in atmospheric samples. (ii) Asbestos fibres from brake linings operated under norm;tl conditions have the same cr}stal structure :ts ;tshcstos from other sour<::<!s. The ahs.:n~:: oi th::rrnat!y-degradcd material cannot. therefore:. be taken as evit!::ncc: that brakes have not contributed to a panicul:lr sample. (iii) Th.: results from the samples coll~c:ed at the freeway e.v,it suggest th31 emissions from brakes c:ln becom.: airborne. Tho! concentrations r~:.tched are very low. below the recommended <!:(posu~e standard (:\JOSH. 1972; U.S. Dept. Ltbor. 1972). J.nd consistent with the pr.:diction by oth.:r worker; that only a small fra~.:tion of th:: total dust formed t-ecomes airnom~ (Jacko. L'( 11., ! 973). Ad..uml,dH<'IIIl'llh-Tf:c ;wthvrs wou!J like t.:~ thank. Dr. J. V. San<.krs.C.S.l.R.O.. Di,i:iiun ofTrib<Jph:-si.:s. l..iniversity of l\ldbourne. for considerable ussi:;tanc.: and use of ckctron microscop~ fC~cilitic:s. One of us. J. .~!st.:. wishes to th3nk A.C.I. Fibr~gLlss for support durii"lg ;his work. HEn.HE;'\CES G.h.b-.!n J...\ .. P~!rk~r J :tnJ Sn1ith \V. L. 1 tY- J_l :::):;t:!rmina 1i.._"~n of chr)Sl)tik in ~\irbornl! as~;.:stos b) J.n i.r. spt:ctro metric technique. Amwspheric Endromn<'ll! 4, 667670. Holt P. F. and Young D. K. (1973) Asb.:sto~ fibres in the atmosphere of town$. Atmosplleric Er.drorment 7, 4!11- 433; 669-670. Jaclw G. J.. DuCharme R. T. and Somers J. H. (1973) How much ;1;bcstos do whiclcs c:mif! Auto E"Y"IJ 81. 3~-40. Kecn;m R. G. and Kupel R.. E. (t96g) ~lod..:rn techniques for evaluating mixed environmental exposures to fibrou> and parw:uiJ:e .:h.:;L; in th~ '1slxsto; industr). Pn:-print U.S. Public H.::1l!h Ser\"ice. l"1tional Centre for Urban and Industrial He~!Lh. Cinndnati. OH. lane R. E. ,r ul. 1.196:>) Hygiene standards for chrysotih: asbc>tos dust. ..J11n. O~:cup. fly!). II. 47-b\l. Lyn.:h R. J. (196SI JO:h Annual :-.teeting. American conference of Governmenr Hygi~nists. St. Louis. :-..10. McCrone W_ C. and Ddly J. G. ( 1973) TJ,._. Purr ide Arl<~s. Vol. 3. ~nJ EJn. p. 5S6. Ann .-'\rbo; Sci~~ce Publi>h.:rs.. Ann Arbor. MI. M.:rowoth.:r E. R. A (19301 The: o.;ct>rrenc~ of pulmonary fibrosis and oth~r pulmon;try inf.:ction~ in asb.:stos work.:rs. J. !d. Hyy. 12. ~39-.:!S:'. N~ws Focus (197.>} EPA s.:ls fin;1l emission >tandard for asb..:stos, bcr) llium. m.:rcury. 1. Air Po!/L,r. C'uncrol .-lss. 23. 3'iS. l"ich.;>lson W. J. Lant:er t\. ~1. a:!J Sdi:.:,,tT I. I !9731 Asb-estos in th" atmo,;ph.:rc of t.;>\\OS. ..tm:v,rlwric Enriroum,llf 7. C'66-o6~. NIOSH (197.:!) Ccit"ria for a recommonc~d standard. 0-:cupation:t.l "xposuro to asbcst.:>s. Document HS:'-.1 7~-10.:!61 -i-(1972~ U.S. Dept. of Health_ Education and Welfare. Pierson W. R. tltl..! Brachtlczk \\". W. 11975) ln-tra!1k "measur~ment of airborne tyrew~:J.r parti~ulate debri$ J. ..tir Pollut. Concrol Ass. 25. -l\l-14llS. Rohock K. ..~.d 1\.lost..:rkoa..:r W. (19731 lnw,tigations in th~ cytoto:.icity of ;lsb..:stos dusts. Sr""" ~J. 27') 2~;. Schurz,\. anJ WviLo\\itJ. H. J. (1973) Tcdllll-:al '''ulllard \~dU'-!S fvr : ~>.: .:Jn"'.ij:;ibk Wl"~rk!n:;_ rLh:~o: Cl)llL.:~ntratH.)I\ or ~hr\:iOtd~ ~b:~stas. Shlldt J.:t ~~5-~511. Se!ikoff !. 1.. );i.:~ol;;on W. J. o.r.J Ling~~ A. \I. t('}J2J Asbestos air pollution. ..trd1. frlriron. /H:I 25. I 13. U.S. D~pt of Labor. ( 197.:?) Washin~ton lnf,,rmation docu- ment T.:!-366. Yatla K. (19671 Stud) of chr)sl.ll;k ashcsto$ by a high r.:~oluti0n n1icros~opc.. ..toq Cry:H. 23. 70-.1.-707. YaJa 1\.. ( 197!) Stutly of microstructur.: of .:hrpoti!~ ash...-.tv::i t>: hi~h r~S")tutiun nlicr..,:-;~.:\.)P} .kla Crysr. :\21. 65~ fl~,_; \ I J FMSI 06066 201 KING MANOR DRIVE, KING OF PRUSSIA. PA 19406 (2151 277-3900 April 20, 1979 Mr. I. H. i'leaver Corporate Director Envir. R~YBESTOS-~~~~~TT~~ 123 E. Stiegel St. Manheim PA 17545 Control Dear Ike: I thought you would be interested in the enclosed report from Dr. Arthur Rohl of .Ht. Sinai Hospital Medical Center. We have been anxiously awaiting the results of Dr. Rohl's tests and needless to say, are very pleased with ~he repo~t and what he has to say about NIDFISK'S ASBESTO-CLE~G systens. Sincerely, NILFISK OF AMERICA, INC. 1M )Ju.qtZ.der-4-J Robert S. Hagd.f.Lain j President I RSM:ds Enclosure 1- t\/ r l4 ) FMSI 06067 l ... h - - : :~ ~ .......~:--. ' "-l '" 't~ ..:;, April 11, 1979 , ., ; .-... -. :: ...; . . .... i .; ' .. Mr. Robert S. Magdelaic, President Nilfisk of America, Inc. 201 King Manor Drive King of Prussia, Pennsylvania 19406 -; _... .: Dear Hr. Hagdelain: This will report the results of air sampling tests conduct_ed, in October 1978, to deterEine chrysotile asbestos concentrations during brake repair work. Our major objective was to determine the efficiency of the Nilfisk Asbestos System utilizing REPA filters, particularly with regard to submicroscopic asbestos fibers. Studies conducted in our Laboratory and else~here have demonstrated that free asbestos fibers present in brake drum du3tS are predoninantly shorter than 5~m in length. In particular, it was found that about 75% of the fibers in such dusts were less than 0.3~rn in length, as determined by transmission electron microscopy. Thus, the optical nicroscopic technique used by OSRA for determining asbestos levels in workplaces (in which only fibers 5~~ or longer are counted) would overlook a large number of asbestos fibers in air samples. That is, the total asbestos exposure in terms of fiber nunber, mass and surface area would be significantly greater than the levels cetermined using the OSHA fiber-counting method. Therefore, it was of considerable interest to us to have an opportunity to test the efficiency of the Nilfisk Asbesto-Clene Syste~. To do this personal air sa~ling was carried out on the exhaust of a HEPA-filtered vacuu~ dust collector and, simultaneously, o~ a garage mechanic cleaning a brake drun with the ~iilfisk brake encapsulation cylinder. Three su~h tests were ~de. Background air samples, also using personal air pumps, were taken. For each of the tests, a sample of settled dust ~as taken from the brake drum. The dusts were analyzed by x-ray diffraction in the stepscan mode to quantitatively determine asbestos contents, using a technique previously published. Asbestos was found in all three samples, ranging from 2.5% to 4.5% by weight. The menbrane filters were analyzed by both transnission electron microscopy (X25,000) and by the standard OS:r-'\ fiber-counting technique, employing phase contrast optical microscopy. The results are as follows: FMSl 06068 :Hr. Robert S. Magdelain, President Page 2 April 10, 1979 Sample Description Nanograms/cu =eter Fibers/milliliter (electron micrcs.::oo,~) (cotical microsc:o;rv) N-1 N-2 N-3 TEST H .Backgrour.d (70 feet from o~erator) Operator (breathing zone - 6 ft. from dust collector) Dust collector (HEPA-filtered vccu~) 400 0 0 0 0 0 TEST :!]. N-4 Background (70 feet fro~ operator) N-5 Dust collector (REPA-fil~ered vccuum) N-6 Operator (breathing zone - 6 ft. fro~ dust collector) 615 0. 59,000 0.12 0 0.5 TEST #3 N-4 "Background (same as in Test 2) N-7 Operator (breathing zone - 6 ft. fro~ dust collector) N-8 Dust collector (HEPA-filtered vacuum) 615 0 0 0.12 0 FMSI 06069 ,. ' Hr. Robert S. Nagdelain, President Page 3 April 10, 1979 Remarks and Conclusio~s~ The tests demonstrate that asbestos levels are virtually eliminated by the use of a system ~~playing brake encapsulation device connected to a HEPA-filtered vacuu~ dust collector. ~ithout the use of such equipment, fiber concentrations during compressed air jet-blo~ing of brake druns ranged from 6.6 to 29.8 fibers/nilliliter. Hc-.-ever, when the Asbesto-Clene System was used, fiber concentrations on both the mechanic and dust collector exhaust were not detected, as verified by transmission electron microscopy. An ioportant exception to this is observed in Test #2, the sa~ple t2ken on t~e operator. Prior to this test, this mechanic had ~orked on brake jobs without using the Asbesto-Clene System and without changing his ~ork clothes. This exposure hac resulted in contacination of ~is clotGes, reflected in the high residual asbestos concentration of 59,000 nanograms/cubic reeter a1~d 0.5 fibers/milliliter. In contrast, the operator in Test fil and Test {t3 'Wore clean coveralls. This points up the need to adhere to the OS~\ regulatio~s concerning S?ecial clothing, change rooms, etc. to nini~ize conta~ination. The background asbestos measurements, 0 400 and 615 nanogra~s/ cubic meter, are consistent with other b~ckgrou~d measure~ents taken during brake repair work. They are the result of residual contamination of the garage by asbestos. This study has been unique and fortu~ate in b'o respects; first because of the great ir.terest and iwportance of deterffiining chrysotile asbestos levels in such circu=stances. The data indicate that the Asbesto-Clene Syste~ represents an outstanding advance~ent in industrial hygiene procedures to control asbestos exposure. It has also been a pleasure to ~ork with you in preparing and conducting these tests. If there are any questions regarding the results or conclusions in this report, please do not hesitate to contact me. ['.. ~~\~ Arthur N. Rohl, Ph.D. Enviro~ental Sciences Laboratory ANR:jm FMSI 06070 Asbestos Health Hazards There have been a lot of stories lately about the hazards of breathing airborne asbestos fibers. Is asbestos still used in brake linings? It is common practice to blow the brake dust out with compressed air,to clean the brakes. Does this present a health hazard? Is there a risk to motorists from brake dust in the air near streets and highways? Ken Bohn Louisville, Kentucky Asbestos is the name for a family of silicate minerals that occur in nature in the form of ultra-fine, brittle fibers. Asbestos has a high resistance to heat and is still commonly used as insulation or molded (with other materials) into clutch and brake linings. In molded form a~ bestos is safe but when the fibers are released (from wear or from cutting or sanding the molded material), they present an insidious health hazard. The fibers are so brittle that when they are broken, they tend to disintegrate into particles too small to be seen (an electron microscope is needed to see the smallest, most harmful particles). According to current medical research, usually there is no sign of asbestos-related diseasefor J(J...35years after the first exposure to asbestos particles. After this incubation period, the fibers can cause asbestosis, a disease characterized by severe scarring of the lung tissue, and mesothelioma, a cancer ofthe lining ofthe chest and abdomen. Asbestosis usually doesn't kill directly. Its victims genera'liy succumb to related respiratory infections such as bronchitis or pneumonia. Exposure to asbestos fibers also greatly increases the risk ofcancer ofthe lungs and esophagus, stomach, kidneys and larynx. Cases have been found where family members of workers exposed to asbestos fibers developed asbestos-related diseasesjust from exposure to asbestos fibers on the worker's shoes and clothing. Motorists and pedestrians have little to fearfrom inhaling brake drm. There is some brake dust in the air near srreers and highways, but thenumberofparticlesis very smalland they tend to sertle our ofthe air, so the overall risk is virrualll' nonexistent. To reduce the risk of asbestos-related diseases, avoid contact with asbestos particles, especially airborne particles. lr's usually a good practice to clean any component before reassemb~y, but" with brakes and clutches, it's better to lea\'e the brake or clutch dust in place, where it does no harm, rather than to use compressed air to blow it out and risk inhaling the asbestos fibers. ifyou must clean the parts, use a vacuum system or rinse the parts in solvent and wear disposable gloves. Clutch or brake linings shouldn't be allowed ro soak in the solvent, as this can damage the lining material. Discard the used solvent and wash your hands immediately so you don't spread the particles around. To cut or sand clutch or brake linings, use a ventilation system designed to suck in the asbestos dust before it can be inhaled and wear a dust or paint mask. To clean brake dust from the wheels, use a detergent solution and rinse with a hose or use a high-pressure cleaner at a self-service car wash. Information on health risks associated with asbestos exposure is available from N!t7jc,.vA.L ('dA/t;:td! INSTtTcq .' F ........... - FMSI 06071 NY, Bus fleet praised for ity fighting asbestos an antilan $10 hazard Fainst the ork and or its "excellent performance in protecting district mechanics 1e Port from a cancer-causing substance, opoly to asbestos in fiber form," California's e use of Health Dept. has commended the al. Golden Gate Bridge, Highway and nt strike Transportation District. , saying Golden Gate Transit, operating a reed to fleet of 248 buses, was praised for of facila(FQ- protecting the 42 district mechanics who work with asbestos lining while performing brake and clutch mainte- paid uthority holding nance and repairs on buses. California is the first state to require employers to report work- ~ year. f from t. plus place use of asbestos. Asbestos is the most widely used of 18 cancercausing chemicals and substances is four .There;equest 1regulated in California as part of a , comprehensive program to prevent ' job-related cancer. Excessive exposure to asbestos ; fees, :mount I ; lease fibers can cause lung cancer, a rarer form of cancer known as mesothelioma, and a lung ailment called asbestosis. ~com thority Jge to State Health Director Jerome A. Lackner, M.D., said, "State industrial hygienists are discovering in inspec- oper- m the I been !ft., to [lpany tions that asbestos in bus, truck and auto brake-repair shops is a significant potential health hazard to California workers, but one which safe work practices can control. "An estimated 74,000 mechanics ts are and other workers in 22,000 autoand brake-repair shops serving the '5.5% enver public are potentially exposed to asbestos through brake-repair work. !~bsoiud-r 1illion [linals 'lillian 't the 1 bus 1rts. ? of Several thousand more workers doing brake repairs for transit systems, truck and bus lines and utility-vehicle fleets potentially risk similar exposure. Several citations for unsafe use of asbestos have been issued. "So it is encouragingly good news when we learn that a large fleet operator such as Golden Gate Transit is effectively protecting its :pay ;evin c.::;~ mechanics against exposure to abestos fibers. "The district's San Rafael brake repair facility is an outstanding exam- pie of safe asbestos use. It is well equipped to minimize dust. The district mechanics are using safe work practices." The district mechanics are members of the International Association of Machinists & Aerospace Workers (lAM), Marin County Lodge No. 238. The Machinists union was represented, along with employer, government, and science representatives, on the State Health Dept. advisory committee, which early this year drafted the asbestos regulation now in effect. Dr. Fred Ottoboni, Ph.D., head of the department's Occupational Cancer Control Unit, said the transit district followed these key procedures to maximize worker protection against asbestos fibers: 0 New brake linings are "arced" (shaped to fit) with a low-speed lathe rather than a p.ower sanding machine that could produce airborne fibers. 0 Arcing is done in a room separate from other workers so that asbestos waste is isolated from other workers. 0 The small amount of dust generated by this process is collected by an exhaust system. 0 Waste material is put in labelled containers and disposed of in plastic bags. 0 Cleanup of brakes prior to repair is done with a damp rag rather than with compressed air, thus eliminating a serious source of dust. - Anti-lock backflip stirs bus protest The American Public Transit Assn., Washington, D.C., has protested the now-we're-against-it, nowwe're-not moves of the DOT's Truck and Bus Safety Subcommittees on the anti-lock provision of FMVSS 121 (F0-11/77, p. 13). APTA, whose members carry 90% of U.S. mass transport riders, wrote to William H. Marsh, executive secre- tary of NHTSA, protecting the sub- committee's reversal of a morato- rium recommendation approved by a majority of members at a proper meeting. APTA's executive director B.R. Stokes said, "It is unconscionable to attempt to reverse this action by the very questionable procedure em- ployed. The safety of the public is too important to allow several indi- viduals to sidestep usual democratic procedures. "To reverse a carefully considered committee action (within one week) by a telephone/telegram ballot, without even a claim of change in circumstances, presentation of new evidence or the like, is a transparent ploy inconsistent with any procedure acceptable to our courts of law, our congressional representatives or our sense of justice." lrC;I .Retrofitted bus takes wheelchairs A 7-year-old Toledo (Ohio) transit bus has been retrofitted with an electric lift platform to accommodate disabled passengers (photo above). Inside the bus are six restraints to keep wheelchairs in place while the bus is moving. The platform, designed by City Machine & Tool Div. of Sheller-Globe, replaces the rear step well and also serves as a standard passenger step entrance. Modification was made with help of a grant from the Urban Mass Transit Authority. - l I:1978 FLEET OWNER I JANUARY 1978 ------.~ --~~--..,..........--.,...._----~------......... 121 FMSI 06072 l l .I I top ofthenevvs Find more work-related cancer A government study estimates that at least 20% and possibly as many as 38% of the cancers that will occur in the U.S. over the next 30-35 years will be work-related. This conclusion represents a significant departure from conventional estimates, which have ranged from 1-5%. Results of the study, prepared by the National Cancer Institute and the National Institute of Environmental Health Sciences (NIEHS), were disclosed last week by Joseph A. Califano, Jr., Secretary of Health, Education and Welfare. The complete report will be submitted as evidence to the Occupational Safety and Health Administration. The authors want it to be used as part of the data on which OSHA will base its policy for regulating carcinogens. The HEW report represents a re-evaluation of available studies on occupationally-related cancers, particularly in the light of new evidence concerning the impact of asbestos-related cancer. It predicts that 2.15 million persons will suffer cancer attributable to asbestos over the next 3035 years-an aver.age of almost 67,000 cases/year. This would represent about 17% of all cancers detected annually in the u.s. Commenting on the asbestos threat, David P. Rail, director of NIEHS and one of the authors, notes: "It is only in the last year or so that the full magnitude of the asbestos situation has been appreciated." In addition, four other substancesarsenic; benzene; coal-tar pitch volatiles and coke oven emissions; and vinyl chlo- NIEHS's RALL: Figures show "we're not in as good shape as we may have thought." ride-will result in 1-3% of cancers each year, the study says. Four other compounds-chromium; iron oxide; nickel; and petroleum distillates-will contribute to 3-18% of all cancers. Thus a 20o/o figure is a "conservative" estimate, Rail says. The figures do not include the potential effects of other unknown substances, Rail notes. But the study does carry a caveatit notes that most cancers have multiple causes. Rail says a number of occupational groups, such as chemists and rubber workers, have been found to have an excess incidence of certain cancers but the specific causes are not known. While Rail conceded that the estimates of the number of workers exposed to carcinogens are probably not accurate, lie notes, "They are the best estimates we have," adding that they may in fact understate the situation. "The typical pattern is that the more you study an occupational group, the more relative risk you see," Rail observed. In his view, the message of the study is: "We really have to work much harder to make the workplace safe from chemical carcinogens. There may have been some feeling of complacency, but we're not in as good shape as we may have thought." OSHA Administrator Eula Bingham underlined Rail's comments, noting that "the study came as no personal surprise" and labeling it as "a clear call to the nation for action." The study indicates that cancer is not necessarily "inevitable," Bingham says, adding that "we should launch an all-out assault to rid workplaces of cancer-causing exposures and turn out energies toward preventive rather than remedial programs." Industry officials denounced the "premature" use of the HEW Blair, Dow Chemical's .vice president for Health and Environmental Sciences, noted that Califano's decision io release the results is "most unfortunate" and "uncalled for" because the report is in draft stage and so far "unsubstantiated" by data. Blair believes the estimates are another in a series of predictions that are periodically tossed out and not substantiated. "A better procedure would be for these people to have peer review of their study. Many scientific groups or technical people arc all qualified to examine this." Blair's sentiments were echoed by the American Industrial Health Council and the American Council on Science and Health. AIHC Executive Director Ronald A. Lang said the summary released by HEW did not clearly identify the scientific methods used, or the details of the study's results. "The summary Mr. Califano refers to tells us nothing," Lang notes, adding that any new data on cancer from occupational exposure "should be published and critiqued ... before HEW alarms the public unnecessarily." ACSH's Executive Director Elizabeth M. Whelan noted that the report "was seriously misleading in that it cited cancer mortality statistics among asbestos workers without even mentioning the contribution of the major lung carcinogen-cigarette smoke. Non-smoking asbestos workers have no more lung cancer than the general non-smoking population." AIHC's Lang added that asbestos exposure conditions that the study linked with 17% of all .cancers "were cleaned up long ago." . Cancer link denied Dow Chemical says that it will "vigorously contest" a $70-million lawsuit brought by a Vietnam veteran who claims that he developed a fatal cancer as a result of exposure to Agent Orange herbicide. Last week, Dow responded to the suit by petitioning to have it moved into U.S. District Court from New York State Supreme Court where it was originally filed late in July. The suit by 28-year-old Paul Reutershan originally named Dow and five other companies thought to have supplied the defoliant-a blend of 2,4,5-T and 2,4-0 herbicides-to the military. On Sept. 6 action was dropped against all but Dow. In the complaint, Reutershan charges that his cancer was caused by exposure to Agent Orange while serving in Vietnam in 1967 and 1968. He discovered that he had cancer in October 1977. He claims that Dow was aware of the alleged harmful affects but failed to warn those exposed of the potential danger. According to Dow, the move to federal court will give it greater freedom in exam- . ining expert witnesses called by Reutershan to prove his case. Dow maintains that there is no evidence that Agent Orange causes cancer. Reutershan's attorneys say that this is the first case brought by a veteran over Agent Orange and that others may join the suit. However, a veterans' group called Citizen Soldier says that while a number of veterans seem to have symptoms consistent with dioxin-an inevitable contaminant of 2,4,5-Tproving the connection with cancer is difficult. The group says it is laying groundwork for an epidemiologic study of veterans exposed to Agent Orange. 22 CHEMICAL WEEK September 20, 1978 FMSI 06073 July 1978 Volume 42 Number 7 INDUSTRIAL HYGIENE DIGEST ~'r\1-;-"--"' vvC Industrial Health Foundation 5231 Centre Avenue Pittsburgh, Pennsylvania 15232 NEWS ITEMS 663/78x Actions on the Threshold Limit Values of Chemical Agents. American Conference of Governmental Industrial Hygienists, May 1978. Notice of Changes Intended (For 1978) Additions Aspirin IAmosite Chrysotile Crocidolite Cyanogen Chloride Baytex 1, 3 Dichloropropene Divinyl benzene o-sec-Butylphenol Chloroacetyl Chloride Diethanolam ine 2-Hydroxypropyl acrylate Dalapon m- Isopropylaniline Propionic acid Sodium bisulfite Tetrasodium pyrophosphate Trichloroacetic acid 5 mg/m3, 0. 5 fibers/cc 2 fibers/cc 0. 2 fibers/cc 0.25 ppm 0.1 mg/m3 1 ppm '10 ppm 5 ppm-Skin 50 ppb 3 ppm 0.5 ppm-Skin 1 ppm 2 ppm-Skin 10 ppm 5 mgtm3 5 mg/m3 1 mg/m3 Deletions 140 Flash aliphatic solvent N-Methyl -2- pyrrolidone l FMSI 06074 '. - . ....,..:::_ ----..J..-~- TECHNOLOGY Flash filling for front teeth The time pressure is off on dental fillings with a composite developed by Imperial Chemical Industries in the United Kingdom. No longer must the dentist rush to fill a difficult cavity or build up a chipped tooth before the filling material hardens. According to a report in the May 8 CHEMICAL AND ENGINEERING NEws, the new blend, called Fotofil, remains a paste until its catalyst is activated by light from a special source "gun." The paste then cures within a minute to an inert structure, which matches the enamel of neighboring teeth. The active component of the paste is a resin made of urethane dimethacyclate, a member of the family of materials used to coat chemical tanks. A barium-containing glass filler makes up 80 percent of the paste formulation. The glass is ground to particles of 10 microns and coated with a silicon compound. The dental material is soon to be marketed in the United States for restoration of front teeth. Molars, however, require a subtance highly resistant to abrasion. The developers are now investigating whether Fotofil or modifications with different glasses and resins are suitable for back teeth. Unlimited time for sculpturing molar work would be especially valuable because accurate shaping of molars prevents wear on the opposing teeth. Sifting through the silicon Finding a needle in a haystack is a difficult type of research problem, whether it involves trace impurities or basic constituents of chemical and biological systems. Researchers at Bell Telephone Laboratories report a new electron microscope technique for identifying and locating minute amounts of certain elements in diverse materials. So far, researchers have used it to identify a few hundred carbon atoms among several hundred billion silicon atoms, unwanted oxygen, nitrogen and carbon in integrated circuits and the storage site of the neurotransmitter serotonin in human blood platelets (reported in the May 5 ScmNCE). The technique, called electron energy-loss spectroscopy, locates atoms of different elements by their interactions with a beam of electrons generated by the microscope. The beam electrons lose a characteristic amount of energy when they interact with each type of atom. David Joy and Dennis Maher then use a magnetic field to sort the beam atoms by amount of energy lost. In addition to detecting small amounts of elements, the technique allows scientists to measure distances between atoms to within a quarter of the diameter of one atom. Roy Rogers to the delivery Cows in labor may soon be calling cowboys, if the Federal Communications Commission approves a new device. A matchbook-size transmitter held in place by an adhesive signals when the cow's cervix dilates just before giving birth. The cowboy's receiver picks up the signal, which directs him to the bearing cow. The reusable device, which has a range of IS miles, was developed by Warren R. Jewett, Walter Evans and Lee Ingle of the University of Arizona. Bill Clevenger of Vita Vet, the company that plans to produce the detectors, estimates that 10 to IS percent of unattended livestock births" result in death to the newborn. Cattle and horses don't always take care of their new offspring or protect them from predators. The device will also be useful for zoo animals that often kill their newborns. Jewett's work on a birth signaling device began with an inquiry from the St. Louis Zoo. To save snow leopard cubs, zoo attendants need to be on hand to separate the cubs from their mother within 30 minutes of birth. MAY 27, 1978 People pollution Just breathing can make a room without ventilation that is also full of people pretty stuffy. How stuffy? Tsen C. Wang, a chemical engineer with Harbor Branch Foundation in Fort Pierce, Fla., rigged up a monitoring system to find out. Results. in the March CHEMTECH, showed elevated levels of carbon dioxide, carbon monoxide, alcohol, methane and acetone. Wang plotted accumulation and decay rates for C02 over time, and the steady-state contamination levels for each chemical based on the number of people in the room. Equations derived from the data permit fairly accurate predictions of necessary ventilation. Asbestos pollution from auto brakes Suspicion that automobile brakes release deformed "chrysotile" asbestos has been confirmed by Krishna Seshan. a materials science engineer at Lawrence Berkeley Laboratory in California. Most cars brake by grinding pads against a heat-resistant asbestos brake lining, Seshan says. His work shows that this deforms asbestos fibers, which are released as dust. And studies indicate that when asbestos is deformed, its surface electrical charge is altered, increasing its biological activity - and health risks, Seshan told SciENCE NEws. Asbestos has been linked with both lung disease and cancer in humans. Deformed asbestos had been detected in air samples near highways. but scientists could not be sure where it originated. Seshan reasoned that highly deformed fibers probably came from autos, slightly deformed fibers from building-construction materials and undeformed fibers from natural rock. Since crystals "carry a memory" of their original structure despite later deformation, Seshan figured he might be able to correlate the degree of deformity with the fiber's source. He examined brake-drum dust using dark field image electron microscopy (a way to observe small particles by looking at diffraction patterns of scattered electrons); the technique is common to microscopists, Seshan says, but relatively ignored by environmental scientists. Not only did he verify the presence of asbestos, but he also ascertained that fibers ranged from slightly to very deformed. He describes his work in the June ENVIRONMENTAL RESEARCH. . There is probably little risk to drivers because of the small amounts they would inhale, LBL says. Not so with mechcsa; n/' those who clean brakes using compressed air might inhale up to one million particles per. cubic meter of air, LBL says. Air pollution: More bad news Results of a study conducted in Allegheny County, Pa., for the Environmental Protection Agency add weight to the theory that air pollution reduces life expectancy. Using statistical data lor 1968 to 1972, John J. Gregor of Pennsylvania State University (now of Plymouth State College in New Hampshire) found that reducing total particulates one percent corresponded to a 0.23 to 0.89 percent reduction in pollution-related deaths. He cautions against extrapolating results to other regions, because it is not clear "whether the relatively large influence" of particulates on death rates is due to specific pollutants or to "inherent characteristics of particulate matter." For example, he found the correlation between sulfur dioxide - one of the particulate pollutants- and deaths was statistically insignificant. The study, Intra-urban Mortality and Air Quality, also con- cludes that air pollution impacts increase with age. indicating either that the body's ability to counter effects decreases. or that pollutants have a cumulative effect. And although impact on both sexes is near equal after age 65, before 6S men show more adverse effects than women. y,.;!;},/.~ FMSI 06075 349 _,,v-.~-. ~ ~~ ~iJ\;.!J;g 17-e m~~~t~ ~ 'tB ~~u~ut~ "~~'= h"""~ ~~ .J..;J ~~&m~t'1;-) ~t~@-l~~1~1f G~"i~l tS.h~~ ~o ~ a~,.~~\,1 OSHA YJiU soon be around ... asbestos is a danger to your employees Last month, we introduced the pro- industries (the miners were -under posed changes in the asbestos regula- another law}. Of the nearly one million tions and briefly outlined some of the standards your shop must meet to obey Use of the common sense them. This month, we will taKe a closer NIOSH guidelines will mean look at some of the specific standards affecting your business, show how much danger is involved in handling asbestos and present some of the solu- greater shop safety and could help you pass OSHA industrial hygiene inspection. tions parts and equipment manufacturers have developed. When the 1974 asbestos inhalation law went into effect, most of the concern was for those employees involved in milling, fabrication and construction . A dusr colleclion system designed for use wilh Ammco Tools, Inc.'s brake shoe grinders (Model 8925) efficiently collects, contains and disposes of asbestos dust ground off brake shoes, according to the company. No external power source is required, as a buill-in suction fan pulls dust from the sur- tons of asbestos "consumed" in the United States in 1972, approximately 77% was nsed in the construction industry. However, further statistics reveal that only 500,000 workers are exposed to asbestos in mining, milling, fabrication and construction. Compare that number with the nearly one million American workers exposed to asbestos while installing and/or maintaining clutch and brake linings! A smaller per- face of the brake shoe and deposits it in a centage of the total asbestos is con- sealable disposable plastic bag. Once instal- sumed but a larger percentage of led, the brake shoe grinder is said to meet or America's work force is exposed. exceed Federal Clean Air Standards set by the OSHA Act of 1970. But how serious is the exposure? A 1975 c-.;: - ~~--, study done by Dr. W.J. Nicholson of Mt. Sinai Hospital detailed in a paper entitled "Asbestos Exposure During Brake Lining Maintenance and Repair" reyeals some interesting statistics. l~l Before studies were undertaken, it was thought that the heat involved during the use of brakes caused a chemical breakdown, transforming the asbestos in the linings into a relatively harmless dust. The data presented in the paper indicates that workers engaged in car --gn (fl 0 al 14 ~ t:;;--1J ~ and truck brake service are exposed to potentially hazardous levels of airborne asbestos dust. BRAKE AND FRONT END al ...SpeGifu:.b.rake., .se(vkiJ;g. OJ:Wr;atiGns, ...per cubic .ceRtimet.er. Specif::;.c.l!y, the studied in;;luded blow-out of au- Federal Register states "The S-hour tomobi!e brake assemblies, grinding of time-weighted average airborne, con- used truck brake linings and bevelling centrations of asbestos fibers to which of new truck brake linings. Average any employee may be exposed shall not peak asbestos air concentrations for exceed two fibers, longer than five mic- these three activities based on personal ron, per cubic centimeter of air." samples taken within 10 feet of the The measurement is done by using a operator were, respectively, 10.5, 3.75 membrane filter method with an elec- and 37.3 fibers (great~r than five mic- tronic microscope costing between rons in length) per cubic centimeter, up $500-$1,000. Obviously, this is too to 19 times worse than the recom- costly for most brake shops. Some in- mended limit. surance companies will undertake this The study concluded that "during measurement for their accounts, pro- brake lining maintenance and repair, viding the insurance company has an workmen in garages, service stations industrial hygiene division. Also, some and brake repair shops are exposed to state .OSHA offices will help. asbestos and thus may be subject to Regardless who does it, the employer serious cancer risk. Others, at some is responsible for taking the measure- distance from the repair work, (includ- ment. A:1 explanation of t'le membrane ing those who are within 75 feet) are filter method (which is the only accept- perhaps subject to the same hazard." able method according to OSHA) can This study, and others that have been be found in the Asbestos Information undertaken, has established in the sci- entific community a basis for studying the extent of asbestos-related disease in brake servicing personnel. A recent re- view of scientific literature, quoted in an ASIA news bulletin. states that "the association between asbestos exposure and [tumors of the chc~t and . abdommal membranes] has revealed at least four cases of these rare tumors in persons who were employed in jobs involving automobile brake servicing." (Resear- chers have just begun to pinpoint this industry. Other related cases are ex- pected to be found.) Now that the scientific community and the federal governmem are convinced of the risk involved in brake servicing, it is time for the individual shop owner to comply with the standards established by the Dept. of HEW and stated in the Airborne Asbestos regulations. The law states that airborne asbestos fibers must be below a certain count The Brake-0-Vac brake assembly cleaner has been redesigned by Per-Lux, Inc., to meet OSHA requirements by attaching the unit to an approved shop vacuum. When attached to a stand~rd air hose, dust, ashestos and oth~r forezgn mat~er ~an be vueuumed ~!! orake assembbes m secon_ds. AutomatiC or manual models, plus qwckchange adapters from 9 in. to 12 in., are available. ..........,,Gv-;-~: i .>\!t::" ~ " ,..... ~<i' ~ ~!'~_~"\" t:i , ~\.i~fh ;-;"4,. \: -.-~.:' ~. " \ .,.,.Jt! : ;' '~~. .;:~~i-> '; 1& f -~~ ~ ~ Y)~!'~'::J ~' ~. ~ .l '"' .; -;;,d~.: ,,,;,'r.;.. . J. tj,/ .............. - - MAY 1976 15 Y-lO . (., ;1)' . -~ Association's "Recommended Work Practices: Fabrication and Use of Asbestos Friction Materials." It takes 11 complicated pages to explain the procedure. A toll-free call to OSHA's Chicago office revealed that the industrial hygiene inspectors will look favorably on indications of voluntary compliance. (The Chicago office is quite willing to answer any questions on this and any other OSHA regulations. T.he toll-free number is: 1-800-621-0523). The National Institute for Occupational Safety and Health has suggested the following procedures for asbestos brake and clutch servicing in order to reduce exposures: If po~sible, an area should be designated for all brake and clutch repairs. Entrances should be posted with warn: ing sign saying: "Asbestos dust hazard. Avoid breathing dust. Wear assigned protective equipment. Do not remain in area unless your work requires it. Breathing asbestos dust may cause asbestosis and cancer." e During brake servcmg, an air purifying respirator, either single use or with replaceable particulate filter(s), as approved by the Mining Enforcement and Safety Administration of NIOSH, will be wo'm during all procedures starting with the removal of the wheels and including reassembly. Such a respirator should a!so be worn during all clutch procedures from removal to installation Model 1250 brake assemblv washer introduced by Ammco permits soi,ent washing of brake assemblies and <liminates the practice of air-blasting asbestos particles and dust around !he shop. The specially designed gun, ><hich requires shop r.ir pres- sure, delivers a properly atomized stream of solvent without misting or waste. The solvent returns to the sump through the perforated parts pan for recirculation. As parts are remo;edfrom the brake assembly, ihey are allowed t() drop into the perforated parts pan where 'they are retained until reused or discarded. ~rc:+:~~~~~~~~,t~ Tempo Products Co. offers this brake/ clutch senice ''"cuum (Model AB-7515)jor dry recovery of asbestos fibers. The vacuum is equipped with a four-stage filtration system with secondary fail-safe protection that is said to assure maximum asbestos filter entrapment. Each unit includes ~omplete instructions and all elements necessary for the safe collection and disposal of asbestos fibers. According to the manufacturer. it has been certified to comply with current regulations by an endronmental laboratory when used as instructed. !~;~--~rf? ~1o.:7}.'!',*kf~1':~ ,~7-;,j*':~.\- '(~' w, ~:t,,, :'_~":~~~ -~~;-i ''"-:_"_~~ SJ~?'.}~>-c>(' ,.,.!~\\~j~~;l [-~-l- . .. i-- I- ~-'-:~-1 ':~~ . -' .'4 ~~,,-:__ -: ~~~~ 7: . ~~t~~ ../'' : ~,._:-.-:';",~-- :~-"-.'~ ~"'."'-> <" .,-l~ ~-~.-'""- -_--,_--.--~ "T1 !:,:~::L:,~---3: ~ :c 1tJ) l~ -~ -. '~- -e0n ~ ~ t... . ~t~~~ ~.~co:~- ~;:]0.......... 1-';,v~ -. ~ -~~ ~]" vc ,....... * , BRAKE AND FRONT END 16 of a new assembly. o Dust should first be cleaned from II brake drums, brake backing plates, brake assemblies and clutch assemblies using an industrial typ-e vacuum cleaner 1 1 equipped with a high efficiency filter system. After vacuum cleaning, any remaining dust shall be removed using a rag soaked in water and wrung until nearly dry. Under r.o circumstances should compressed air or dry brushing be used for cleaning. o During arcing and riveting operations, respirator should also be worn. Grinding (arcing) machines should be provided with local exhaust ventilation such that worker exposures maintained at least below the 1976 asbestos standard. o Industrial vacuum cleaner bags containing asbestos dust and cloths used for wiping brake and clutch assemblies should be sealed in plastic bags and labeled with the following warning label printed in letters of sufficient size and contrast to be readily visible and legible, "Caution, contains asbestos fibers. Avoid breathing dust. Breathing asbestos dust may cause asbestosis and cancer." All floor cleaning in areas where brakes and clutches are repaired should be done with a high efficiency industrial vacuum cleaner. Although adherance to the above procedures should minimize any contamination of work clothing, appropriate portions of the OSHA asbestos regulations concerning special clothing, change rooms, etc. should be followed. DATSUN Z. 510, 610. 710. 8210: MAZDA RX 2:3 ~~Q~}~~-"'t"~"r~cm!).~~e, 'r'" .c, robl~rns . IV(i!. S @.,.i ,"'' .""'"""""~.Y:;;:;1::>\4Illilli ~~VI '\'\ <. ~Jy:t~,._~~~-s~~~~ "-:.:;,...:-.,,':(:,,_,-.~,'>_""l. lr~~~\ ~;..,...9'~ 1~ fi! ~~~t~Q:/}::J A rfor ~1a(Ci?herson) Strut Mac Pherson Control Struts. they're good. but they have a problem-tittle or no camber adjustment Now you have a qu1ck solut10n. Install preCISIOn engoneered camber bushings. G1ve your customers betler t~re wear or more responsive handl1ng G1ve yourself that extra adjustment margin so necessary on cars altered or wrecked Install qu1ckly for fast prof1ts. Simply remove lower control arm; press ou! old and slip 'n new oush,ng: reinstall and a11gn. Easy' No dnlling. no weld.ng. no gnnd1ng, no difficult adjustment FAR Performance Inc., Dept. 8Ft, 2240 De La Cruz Blvd .. Santa Clara. CA 95050 ton free 800538e:f911 Compliance to this law will mean not only a safer shop for your employees but it will mean a cleaner and neater shop. Also, be sure your employees understand the severity of this problem so that compliance procedures become standard operating methods in your Catif. 408-249-7990 collect i\, -\{-~~--~/-r ~~ li2~erformance'" shop. MAY 1976 Circle 11 on Service Card 17 ... .'-.. :r ~ , 4 .---::-::; -1 . --, .. j Exc\USl'~:ceru" Beware of Brake Dust! M OST MECHANICS GO ABOUT til ~ of cleaning brake and clutch dust kno' ,'hat while doing the job they are inhaling som l,j~ dust. It has been general knowledge thatli111r,. ,nd pads are made on the average of 50 to no I'',, nt asbestos. However, past studies have ltd '. 1n believe that the asbestos fiber was locked into ,t 111 r materials in the lining and that a change due t1 the high heat of friction took place during braking or clutch application. This transformed the asbestos fiber into a non-toxic, non-fibrous material called forsterite. The conclusion then was that the dust was harmless. Studies conducted by the Mt. Sinai School of Medicine in New York City indicate that brake dust may actually contain an average of 3 to 6 percent asbestos with some tests showing concentrations as high as 15 percent Samples of air were taken under actual working conditions in a taxi-fleet garage and f~ l t a N.Y. Dept. of Sanitation truck repairshop. These . . .plea were analyzed by electron microscopy and ~ Fig. 2. NEVER BLOW OFF dirt from a brake assembly with an rae.! air gun. After vacuuming, use a nearly-dry damp t~ [ revealed levels of airborne asbestos considerablyhigher than those permitted by federal law. It should be noted that during the testipg in the truck repair- shop grinding of brake shoes was carried out.. ~' The work of the ~esearchers at Mt. Sinal was. discussed at a meeting of the National Institute for Occupational Safety and Health (NIOSH) where the results of physical examinations given to 90 men who had been working as automobile and truck- brake repairmen for a period of 10 years were examined. Of this small group the doctors stated that X-ray examinations showed that over one- quarter had signs of ahnormalities ~:onsistent with asbestosis disease; th 'arne tests revealed that one quarter had also r~>"' r ted pulmonary (lung) func- tions. This evid1n . .,.. mpted NIOSH to issue an alert to the atltt>t"'~-+,,(, repair industry indicating that while theEf~.tll ~.ul of asbestos-related disease . ~,. ~ ' ' ' ... ' ' ~-- . ' ;].: : ,.1. ....1i. " in hrake-servic p''JtNJvPI is not known because this oeupalional ~~ ,- not been systematically :-;tud1d up to /otCJ>v eNct".rh scientific data has been <II'<'IIIIIUiatt>d t.. poI-'~ o... f i the need to start , Imme- diatt l'nntrol npfl~"'"' Su that the health hazard of ., . a:.;hcstos ran ht til'"~~'~'~"'-d Tht>rt is no d~.l:ll i h11-1, health hazard exists and I Fig. 1. REMOVE BRAKE OUST with high-efficiency filtered industrial vacuum cleaner. Wear ;~irpurifying respirator. \ 74 r that exposure to ch b.M~.{fhers can increase the riak continued on pag~ \ ~ MOTOR, Marcl\~191"' FMSI 06078 f - ( 3) ..,..,........... VI Ul\,jii\'U' IJU:itll cont~nued from page 74 .~- ,. ,.. o'f developing four diseases: asbestosis-a non-malig- nant scarring lung condition; cancer of the lung; cancer of the digestive tract and mesothelioma-a cancer of the lining of the chest or abdominal cavities. 'l'here are some authorities and other studies that place the percentage of asbestos in brake dust at a much lower level than those reported by the Mt. Sinai group and disagree with its findings. All authorities agree that no matter how small the concentration of asbestos in brake and clutch dust, there is an immediate need to initiate work practices in every shop that will eliminate any risk to the health of mechanics. The danger is associated with drilling, grinding and cutting of brake linings. The dust generated during these operations must be collected in a vacuum-recovery system that has a high-efficiency filter. Many older grinders either have no recovery system or are equipped with vacuums that allow tiny particles of asbestos fiber to be blown into the air. Buying pre-ground shoes will minimize the need for grinding. Where possible, a separate area should be set aside for brake and clutch work and a sign posted at the entrance that reads: ":, ' ASBES"lOS DUST HAZARD. AVOID BREATHING DUST. WEAR ASSIGNED PROTECTIVE EQUIPMENT. DO NOT REMAIN IN AREA UNLESS YOUR WORK .. REQUIRES IT. BREATHING ASBESTOS DUST MAY BE HAZARDOUS TO YOUR HEALTH. '' Dust should never be removed from a brake or clutch assembly with an air blowgun or by brushing. The only way to safely clean dust containing asbestos is with an industrial-type vacuum with a high efficiency filtering system (Fig. 1). Don't use one of your wife's old vacuum cleaners because it probably will do more harm than good. The fine particles of asbestos will pass through most vacuum cleaners and you will end up with a higher eoncentration of asbestos than you would have if you hadn't used the vacuum at all. The vacuum you buy should have a 99-percent efficiency for 0.3 micrometers diameter aerosols. If there is any remaining dust that was not removed by vacuuming, wash it off using a slightly damp rag. Under no circumstances should you use an air gun or dry brush (Fig. 2). 76 .i....._ -- >?1,There is n ,.... nt in being ca~rul about:. vacuuming tht lttl"'' 1f. when you empty the VatUUI~{ t-l~:)l cleaner bag, th IJ<t hlows all around \'QU and the 4~ shop. Brake and ,,,tdl dust should bto <ii!~posed of in .~ a special plast i ' ..,,.. marked as folio"- CAUTION: CO:\ I \I ~S ASBESTO.._ H IH:RS. "'T..\\ c liD RREATHJ:'\f; Ill BUE.\THING ASHJo:STt'"' IHTST !\fAY CAUSJo: SJ-~Hit H .., BODILY If \H\1. E\'('n using a high...!' ,., 1 industrial vacuum clf'aner will not preVNi' " -...... amount of dust from reaching some noses an.: "no1ras which will inhale it. To prevent this, you _,h!ld wear an air-purifying respirator of either tht throwaway type like those used in body shop!! or unt with a replaceable particu- late filter. Before you huy either type, be sure that it is approved by NIOSH or the Mining Enforcement and Safety Administration. Wear the respirator while you are operating a grinder, drill or when emptying the dust collection bags on your vacuum cleaner. There is bound to be some brake and clutch dust that falls to the floor while you are working, so be sure to use an industrial vacuum cleaner to pick it up. Don't sweep this part of the shop with a broom. A broom has the tendency to flick the asbestos particles up into the air and that is where they are dangerous. The rest is common sense: If your shop has heavy accumulations of dust on lockers, parts shelves, overhead door channels, beams and on window sills there is a good chance that dust contains some asbestos. Wear your respirator and use your varuum cleaner to go over all those hidden places carefully and clean up the dust. Change your work clothes regularly and don't bring them home. Have them washed by an industrial laundry. Wash your hands thoroughly before eating and avoid eating in th<' arPa where you do brake and clutch work. Every shop, liAr!(> or small, is responsible for nweting the rtq'l''rnnts of the federal law which all~ for indust ri . . L~itne inspections carried out 111 'lSHA repre "' ,.. Under this law the level "' .(.,hestos shall . d 2 fibers longer than 5 m rometers per ' meter of air. (For a list ~>' ,,,.~,. firm::; s~ .. : .oidressed stamped post- ,., :n an cmtlo!J \loostos, MOTOR, 1790 t; . i 1y, New Yod H!I.) 1 , ,orh ha::; dettr 1" - :.. of lung cal\ h.tt smoking inereases n~o: people exposed to .... ,.. : .,, dust. In sh "'' have been working. ar.... "1 !,rakes and . -- fnr several years, l~ \Aul," ; .. WisetogiH '' ltHHLing. :.\ :~~-r, mntinued on pag 85 . ..MOTOR, March.19'17 .. \ -.~ ~ ' \- FMSl 06079 ,... cont'inucd from page 7fi It is gratifying to note that a ..: ,.,.. dtal of money and time is heing stwnt by br :. .! h1tch lining manufaeturtn; to dal with th addition to OSHA'~ sptrilk rl 1 ron: , r1 In ,I,,J. ont firm ha~ intludtd usl'flli tr;, 1 thl' warnin).!' lalotl on \'tr~ j,, .. ' lora~ "li I clutch fat'IIIJ.!~ it ,;,lb Thi~ "arn 1in11 m('lldl'd prrdul't"' fill' rtolll<'illg a:-.lo durin!.!: hrak ~n;,.,. 111 '!,.rr "t'l'\"lt't man1: .. ;,, .. training lilm In tht final analysis ~ou are tlw only rtlll' '''' can prottt ~ou r,l'l f from llw potpnt ial dan~r. t' exposurt to a:-;J.,..;tns dust. If you Wl'ar a rtsptr;tt .. r or mask, u"'' .tr approvpd hrakP varuum ,.J,anr. dispo:-;, nf 'l1 dust in tht prt'seritwd manner. vacuum tb tloors and ""~" g-ood common Hens about house dtaning-. t lwrt is little to fear from thl' presPnn of asbestn!< dust. Th<' few extra pr<~cautions involv<'d could prtv .. nt you from contracting a very painful if not fatal di:-;ea:-~e. Start tomorrow to cltan up your act . you owe it 'to yourself, your family and your fellow workers. C .,.,. r . Tc \JW ~ " TOOLS THAT DOT~:::; JC:J r:: ~ . THE FIRST Tt::::] ., J, r ....,~ .. . '.... i ' How to Promote Your Service Department C071linued {rom JWifle ;" the clinic will he f<nnrably impressed and may become customtrs in tht future. A clinic of this type invariably uneoven; tht> Ot'td for much service work, and tht daltr ~hould gt>t ~uhstantial share of this work. The best promotion won't be effective unless the serviee departmtnt can deliver what it promises. Amon I[ t ht most fngut-nt tustomtr complaint.<~ are: work not done when promised. l'ars not repaired prnptrly and hil{h cost of repail'll \fost dealerships ~ill make go<11i on a jolo if th work i:~ performed improperly nr k part is defective. Th~;>st "warranties" arc u:-<tlally informal in nature, l~t~t some .t.al~>rs hav l'lan~ that are spe6fic anrl widely .. 11 rtis1d. Your shop '''JiliJtntl <an also '" .tn .mportant 'lwrchandising tHI An oplltal ")l,.,.; . nmenl machine, for "".rnpl. l'r"-itct:< a ":l't .... ..( the front-end !\t~tup of a r'tbtllffiPr~ o;tr. I wn>rs mderstanci th< palttrn of a " ., '". rno,.;t 1rl' impresseci by ti,ll' d.-alr' o:-.t in ~U<h sophisticated Plj u i1111 r. rhn i- cians in it.-; opration. Finally, never forgcl t hu ,,han- dis1rs are your shop pPr!'ol. n"l Itt high-pressure sale!-!mPIL It cu.. mer with their courtts.\ . "'" lht .;inttr- ity and h;wk up that imprts:-;,. na~. uur Investment in prornoot~o.o&l Jllllrut will pay ofl .' .,..rform- nt and II MOTOR. Match 1977 ,.o#, ':'I' f ,, _ -"'" """'"' ..,..,,_,_,.._..... .. _.~---~ .. with Kent-Moore sp~t.:! t:.i!!co tools for Q.M. and Ar:.C ctrSl Now, the special service tools you need to quickly, properly and profitably aervice American Motors and General Mo'~' 1i:n models are available directly from Kent Moore. Using factory-approved KentMoofe MNice tools (the "J'' number tool spec1f1ed in your Service Manual), you can do those tough jobs much faster and easier than with ordinary shop tools. Kent-Moore tools save you time (which is money in your pocket), unnecessary work, and they help you do the job to factory specs This means greater customer satisfaction. fewer "come-backs." ') yourself to check them out. Wr11e for our new catalog of spec'"' tools for 1977 rnodels. Write to Kent-Moore Tool Division, 28635 Mound Rd., Warren, Mich igan 48092. 1:, " .. ~- . '~ . ,' .t' FMSl 06080 IY, y 'l anti, $10 1st the k and Port oly to use of strike saying ed to f facii(FQ- paid hority :>Iding year. from plus four herequest fees, 1ount lease comority e to >per1 the Jeen ., to Jany ; are i.S% nver our >sidllion inals Ilion the bus ts. of pay ~vin =:;1 Bus fleet praised for fighting asbestos hazard For its "excellent performance in protecting district mechanics from a cancer-causing substance, ~sbestos in fiber form," California's Health Dept. has commended the Golden Gate Bridge, Highway and Transportation District. Golden Gate Transit, operating a fleet of 248 bus~s. was praised for protecting the 42 district mechanics who work with asbestos lining while performing brake and dutch mainte- nance and repairs on buses. . California is the first state- to require employers to report work- place use of asbestos. Asbestos is the most widely used of 18 cancer- causing chemicals and substances regulated in California as part of a comprehensive program to prevent job-related cancer. Excessive exposure to asbestos fibers can cause lung cancer, a rarer form of cancer known as mesothe- fioma, and a lung ailment called asbestosis. State Health Director Jerome A. Lackner, M.D., said, "State industrial hygienists are discovering in inspec- tions that asbestos in bus, truck and auto brake-repair shops is a signifi- cant potential health hazard to Cali- fornia workers, but one which safe work practices can control. "An estimated 74,000 mechanics and other workers in 22,000 auto- and brake-repair shops serving the public are potentially exposed to asbestos through brake-repair work. Several thousand more workers do- ing brake repairs for transit systems, truck and bus lines and utility-vehicle fleets potentially risk similar expo- sure. Several citations for unsafe use of asbestos have been issued. "So it is encouragingly good news when we learn that a large fleet operator such as Golden Gate Transit is effectively protecting its mechanics against exposure to abes- tos fibers. "The district's San Rafael brake .repair facility is an outstanding exam- pie of safe asbestos use. It is well equipped to minimize dust. The district mechanics are using safe work practices." The district mechanics .are mem- bers of the International Association of Machinists & Aerospace Workers (lAM), Marin County Lodge No. 238. The Machinists union was repre- sented, along with employer, gov- ernment, and science representa- tives, on the State Health Dept. advi- sory , committee, which early this year drafted the asbestos regulation now in effect. Dr. Fred Ottoboni, Ph.D., head of the department's Occupational Can- cer Control Unit, said the transit district followed these key proce- dures to maximize worker protec- tion against asbestos fibers: _ 0 New brake linings are "arced" {shaped to fit) with a low-speed lathe rather than a p.ower sanding ma- chine that could produce airborne fibers. 0 Arcing is done in a room sepa- rate from other workers so that asbestos waste is isolated from other workers. 0 The small amount of dust generated by this process is col- lected by an exhaust system. 0 Waste material is put in labelled containers and disposed of in plastic bags. 0 Cleanup of brakes prior to repair is done with a damp rag rather than with compressed air, thus elimi- nating a serious source of dust. ~ tary of NHTSA, protecting the sub- committee's reversal of a morato- rium recommendation approved by a majority of members at a proper meeting. APTA's executive director B.R. Stokes said, "It is unconscionable to attempt to reverse this action by the very questionable procedure em- ployed. The safety of the public is too important to allow several indi- viduals to sidestep usual democratic procedures. "To reverse a carefully considered committee action (within one week) by a telephone/telegram ballot, without even a claim of change in circumstances, presentation of new evidence or the like, is a transparent ploy inconsistent with any procedure acceptable to our courts of law, our congressional representatives or our sense of justice." ,;:::::::;1 .Retrofitted bus Anti-lock backflip stirs bus protest The American Public Transit Assn., Washington, D.C., has protested the now-we're-against-it, nowwe're-not moves of the DOT's Truck and Bus Safety Subcommittees on the anti-lock provision of FMVSS 121 (F0-11177, p. 13). APTA, whose members carry 90% of U.S. mass transport riders, wrote to William H. Marsh, executive secre- takes wheelchairs A 7-year-old Toledo (Ohio) transit bus has been retrofitted with an electric _lift platform to accommodate disabled passengers (photo above). Inside the bus are six restraints to keep wheelchairs in place while the bus is moving. The platform, designed by City Machine & Tool Div. of Sheller-Globe, re- -.- places the rear step well and also serveS as a standard passenger step entrance. Modification was made with help of a grant from the Urban Mass Transit Authority. ,c:::;l 978 FlfET OWNER I )ANUARY 1978 FMSI 06081 Y-/)- 121 top of the lleV\IS Find more work-related cancer HEW did not clearly identify the scientific methods used, or the details of the study's results. "The summary Mr. Califano A government study estimates that at least ride-will result in 1-3% of cancers each refers to tells us nothing," Lang notes, 20% and possibly as many as 38% of the year, the study says. Four other com- adding that any new data on cancer from cancers that will occur in the U.S. over the pounds-chromium; iron oxide; nickel; occupational exposure "should be pub- next 30-35 years will be work-related. This and petroleum distillates-will co.Qtribute lished and critiqued . . . before HEW conclusion represents a significant depar- to 3-18% of all cancers. Thus a 20% figure alarms the public unnecessarily." ture from conventional estimates, which is a "conservative" estimate, Rail says. ACSH's Executive Director Elizabeth have ranged from 1-5%. The figures do not include the potential M. Whelan noted that the report "was Results of the study, prepared by the effects of other unknown substances, Rail seriously misleading in that it cited cancer National Cancer Institute and the Nation- notes. But the study does carry a caveat- mortality statistics among asbestos work- al Institute of Environmental Health it notes that most cancers have multiple ers without even mentioning the contribu- Sciences (N IEHS), 'were disclosed last causes. Rail says a number of occupation- tion of the major lung carcinogen-ciga- week by Joseph A. Califano, Jr., Secretary al groups, such as chemists and rubber rette smoke. Non-smoking asbestos work- of Health, Education and Welfare. The workers, have been found to have an ers have no more lung cancer than the complete report will be submitted as excess incidence of certain cancers but the general non-smoking population." AIHC's evidence to the Occupational Safety and specific causes are not known. Lang added that asbestos exposure condi- Health Administration. The authors want While Rail conceded that the estimates tions that the study linked with 17% of all it to be used as part of the data on which of the number of workers exposed to car- cancers "were cleaned up long ago." OSHA will base its policy for regulating cinogens are probably not accurate, lie carcinogens. notes, "They are the best estimates ,we Cancer link denied The HEW report represents a re-evalu- have," adding that they may in fact under- ation of available studies on occupational- state the situation. "The typical pattern is Dow Chemical .says that it will "vigor- ly-related cancers, particularly in the light that the more you study an occupational ously contest" a $70-million lawsuit of new evidence concerning the impact of group, the more relative risk you see," brought by a Vietnam veteran who claims asbestos-related cancer. It predicts that Rail observed. In his view, the message of that he developed a fatal cancer as a result 2.15 million persons will suffer cancer the study is: "We really have to work of exposure to Agent Orange herbicide. attributable to asbestos over the next 30- much harder to make the workplace safe Last week, Dow responded to the suit by 35 years-an aver.age of almost 67,000 from chemical carcinogens. There may petitioning to have it moved into U.S. cases/year. This would represent about have been some feeling of complacency, District Court from New York State 17% of all cancers detected annually in the but we're not in as good shape as we may Supreme Court where it was originally. u.s. have thought." filed late in July. Commenting on the asbestos threat, OSHA Administrator Eida Bingham The suit by 28-year-old Paul Reuter- David P. Rail, director of NIEHS and one underlined Rail's comments, noting that shan originally named Dow and five other of the authors, notes: "It is only in the last "the study came as no personal surprise" companies thought to have supplied the year or so that the full magnitude of the and labeling it as "a clear call to the defoliant-a blend of 2,4,5-T and 2,4-D asbestos situation has been appreciated." n~tion for action." The study indicates herbicides-to the military. On Sept. 6 In addition, four other substances- that cancer is not necessarily "inevitable," action was dropped against all but Dow. arsenic; benzene; coal-tar pitch volatiles Bingham s~ys, adding that "we should In the complaint, Reutershan charges .i and coke oven emissions; and vinyl chlo- launch an all-out assault to rid workplaces that his cancer was caused by exposure to I I of cancer-causing ex?osures and turn out Agent Orange while serving in Vietnam in energies toward preventive rather than 1967 and 1968. He discovered that he had remedial programs." cancer in October 1977. He claims that Industry officials denounced the "pre~ Dow was aware of the alleged harmful mature" use of the HEW affects but failed to warn those exposed of Blair, Dow Chemical's .vice president for the potential danger. Health and Environmental St:iences, noted According to Dow, the move to federal that Califano's decision to release the court will give it greater freedom in exam- . results is "most unfortunate" and "un- ining expert witnesses called by Rcuter- called for" because the report is in draft shan to prove his case. Dow maintains that stage and so far "unsubstantiated" by there is no evidence that. Agent Orange data. Blair beiieves the estimates are causes cancer. another in a series of predictions that are Reutershan's attorneys say that this is the periodically tossed out and not substan- first case brought by a veteran over Agent tiated. "A better procedure would be for Orange and that others may join the suit. these people to have peer review of their However, a veterans' group called Citizen study. Many scientific groups or technical Soldier says that while a number of veterans people are all qualified to examine this." seem to have symptoms consistent with diox- Blair's sentiments were echoed by the in-an inevitable contaminant of 2,4,5-T- American Industrial Health Council and proving the connection with cancer is diffi- the American Council on Science and cult. The group says it is laying groundwork i NIEHS's RALL: Figures show "we're not in Health. AIHC Executive Director Ronald for an epidemiologic study of veterans I' 1 as good shape as we may have thought." A. Lang said the summary released by exposed to Agent Orange. 22 CHE~ICAL WEEK September 20, 1978 '(- )3 FMSI 06082 July 1978 Volume 42 Number 7 INDUSTRIAL HYGIENE DIGEST ~v~- lndustrial flealth Foundation 5231 Centre Avenue Pittsburgh, Pennsylvania 15232 NEWS ITEMS 663/78x Actions on the Threshold Limit Values of Chemical Agents. American Conference of Governmental Industrial Hygienists, May 1978. Notice of Changes Intended (For 1978) Additions Aspirin IAmosite Chrysotile Crocidolite Cyanogen Chloride Baytex 1,3 Dichloropropene Divinyl benzene o-sec- Butylphenol Chloroacetyl Chloride Diethanolamine 2-H~droxypropyl acrylate Dalapon m-lsopropylaniline Propionic acid Sodium bisulfite Tetrasodium pyrophosphate Trichloroacetic acid 5 mg/m3 0.5 Cibers/cc 2 fibers/cc 0.2 fibers/cc 0.25 ppm 0.1 mgtm3 1 ppm 10 ppm 5 ppm-Skin 50 ppb 3 ppm 0.5 ppm-Skin 1 ppm 2 ppm-Skin 10 ppm 5 mg/m3 5 mg/m3 1 mg/m3 Deletions 140 Flash aliphatic solvent N-Methyl -2- pyrrolidone. 1 FMS1 06083 TECHNOLOGY Flash filling for front teeth The time pressure is off on dental fillings with a composite developed by Imperial Chemical Industries in the United Kingdom. No longer must the dentist rush to fill a difficult cavity or build up a chipped 'tooth before the filling material hardens. According to a report in the May 8 CHEMICAL AND ENGINEERING NEws, the new blend, called Fotofil, remains a paste until its catalyst is activated by light from a special source "gun: The paste then cures within a minute to an inert structure, which matches the enamel of neighboring teeth. The active component of the paste is a resin made of urethane dimethacyclate, a member of the family of materials used to coat chemical tanks. A barium-containing glass filler makes up 80 percent of the paste formulation. The glass is ground to particles of 10 microns and coated with a silicon compound. The dental material is soon to be marketed in the United States for restoration of front teeth. Molars, however, require a subtance highly resistant to abrasion. The developers are now Investigating whether Fotofil or modifications with different glasses and resins are suitable for back teeth. Unlimited time for sculpturing molar work would be especially valuable because accurate shaping of molars prevents wear on the opposing teeth. Sifting through the silicon Finding a needle in a haystack is a difficult type of research problem, whether it involves trace impurities or basic constituents of chemical and biological systems. Researchers at Bell Telephone Laboratories report a new electron microscope technique for identifying and locating minute amounts of certain elements in diverse materials. So far, researchers have used it to Identify a few hundred carbon atoms among several hundred billion silicon atoms, unwanted oxygen, nitrogen and carbon in Integrated circuits and the storage site of the neurotransmitter serotonin in human blood platelets (reported in the May 5 SciENCE). The technique, called electron energy-loss spectroscopy, locates atoms of different elements by their interactions with a beani of electrons generated by the microscope. The beam electrons lose a characteristic amount of energy when they lnt~ract with each type of atom. David Joy and Dennis Maher then use a magnetic field to sort the beam atoms by amount of energy lost. In addition to detecting small amounts of elements, the technique allows scientists to measure distances between atoms to within a quarter of the diameter of one atom. Roy Rogers t(}. the delivery Cows in labor may soon be calling cowboys, if the Federal Communications Commission approves a new device. A matchbook-size transmitter held in place by an adhesive signals when the cow's cervix dilates just before giving birth. The cowboy's receiver picks up the signal, which directs him to the bearing cow. The reusable device, which has a range of 15 miles, was developed by Warren R. Jewett, Walter Evans and Lee Ingle of the University of Arizona. Bill Clevenger of Vita Vet, the company that plans to produce the detectors. estimates that 10 to 15 percent of unattended livestock birthS result in death to the newborn. Cattle and horses don't always take care of their new offspring or protect them from predators. The device will also be useful for zoo animals that often kill their newborns. Jewett's work on a birth signaling device began with an inquiry from the St. Louis Zoo. To save snow leopard cubs, zoo attendants need to be on hand to separate the cubs from their mother within 30 minutes of birth. MAY 27. 1978 People pollution Just breathing can make a room wifhout ventilation that is also full of people pretty stuffy. How stuffy? Tsen C. Wang, a chemical engineer with Harbor Branch Foundation in Fort Pierce, Fla., rigged up a monitoring system to find out. Results. in the March CHEMTECH, showed elevated levels of carbon dioxide, carbon monoxide, alcohol, methane and acetone. Wang plotted accumulation and decay rates for C02 over time, and the steady-state contamination levels .for each chemical based on the number of people in the room. Equations derived from the data permit fairly accurate predictions of necessary ventilation. Asbestos pollution from auto brakes Suspicion that automobile brakes release deformed "chrysotile" asbestos has been confirmed by Krishna Seshan, a materials science engineer at Lawrence Berkeley Laboratory in California. Most cars brake by grinding pads against a heat-resistant asbestos brake lining, Seshan says. His work shows that this deforms asbestos fibers, which are released as dust. And studies indicate that when asbestos is deformed, its surface electrical charge is altered, increasing its biological activity -. and health risks, Seshan told ScrENCE NEws. Asbestos has been linked with both lung disease and cancer in humans. Deformed asbe;;tos had been detected in air samples near highways, but scientists could not be sure where it originated. Seshan reasoned ,that highly deformed fibers probably came from autos, slightly deformed fibers from building-construction materials and undeformed fibers from natural rock. Since crystals "carry a memory of their original structure despite later deformation, Seshan figured he might be able to correlate the degree of deformity with the fiber's source. He examined brake-drum dust using dark field image electron microscopy (a way to observe small particles by looking at diffraction patterns of scattered electrons); the technique is common to microscopists, Seshan says, but relatively ignored by environmental scientists. Not only did he verily the presence of asbestos, but he also ascertained that fibers ranged from slightly to very deformed. He describes his work in the June ENviRONMENTAL RESEARCH. , There is probably little risk to drivers because of the small amounts they would inhale, LBL says. Not so with mechanycs; those who clean brakes using compressed air might inhale up to one million particles per, cubic meter of air, LBL says. Air pollution: More bad news Results of a study conducted in Allegheny County, Pa., for the Environmental Protection Agency add weight to the theory that air pollution reduces life expectancy. Using statistical data for 1968 to 1972, John J. Gregor of Pennsylvania State University (now of Plymouth State College in New Hampshire) found that reducing total particulates one percent corresponded to a 0.23 to 0.89 percent reduction in pollution-related deaths. He cautions against extrapolating results to other regions, because it is not clear "whether the relatively large influence of particulates on death rates is due to specific pollutants or to "inherent characteristics of particulate matter." For example, he found the correlation between sulfur dioxide - one of the particulate pollutants- and deaths was statistically insignificant. The study, Intra-urban Mortality andoAir Quality, also con- cludes that air pollution impacts increase with age, indicating either that the body's ability to counter effects decreases, or that pollutants have a cumulative effect. And although impact on bboth sexes is near equal after age 65, before 65 men show more adverse effects than women. , /,/ FMSI 06084 J' H9 p ,;bestos exposure (. u.r ~t; .u~ ... ke-1~ maintenance and repair orak -~inings may contain as much as 50% chrysotile asbestos, and ti" .Hsin~...grt.'tion of the lining during braking releases fibers, :;orne oi hich .;,ecomo;, constituents of brake drum dust. ~nto d&t 2;eneral environment. An investigation was made to obtain L,..:orm~<Cl.O:C concerning asbestos exposure of automobile and true<~. mai" .ni . -worlm.e, particulArly those responsible for brake--lining work )erso1... l. ai1 sampling was carried out at various auto rq?al.r shops, ~lee .Aepr.:..r s.1ops and several municipal "truck repa:..r shops. it i .. "tim& ..:. that there are about 124,000 men in this worK in New York .:::i-.y .. lon.-,. The 'x;osu.l.'E: of worker::; durl.nb brake-l.Lnl.ng waintu:...l~nce ar. i :paL of L-~~res.; o:.s a oackground to l.nVe:."tigation of tl.ei . heal~-- . xper .... ..: ~his, ::..n turn, nas considerable significance ir, d(;ltermir.~t; ~ ..etht:" .e- .~..ining dust is pathogenic. If it is not, we would have L;:, ....e cc,, ""' egarding brake-lining dust as a source of general envirom.1"'~ .;al "'~- '~"' ,_ to asbestos. On the other hand, if workers exposed to this a .. dt ;:.:. _ -~" to have asbestos disease, then the effects of exposure of tnt;, 6enerc.l po;>- .-latJ...m to "the same dust, albeit at much lower levels, woula ,;.ave --- be further ava:uated. ;,!ateria ls and ne'thods: Personal air samples were taken during brake-linL1g ma .. rn:c. .:e wo- Air "'-'mples Wt.:re also 1.aken at adjacent sites, in...........1..; , '--'~nmer areas ana autc.;nobile showrooms. The standard tech~-'-qu.e.s to.. .ilt. ,- :,r;:>- cessing and L.bor counting which have been adoptea uy t.le o._. patio.> , J. Safety ar.d Health Administration of the Department of Labor. Bot, . -~1.c. ~ and electron microscopic methods were employed, the latter because . :.. great. r.. <JOrit; ,,f asbestos fibers were too fine t.._ b. det;~c"':ed by u: .. cal .nicro .. :opy. X- . y powder diffraction and microch nical .. co:.,<r. ng e c. cron micr. ~co~1c analysos were al&o utilized to 1dent~iy cnrybo .. le asb~~.a~ in bra~o dcum s.:..... ~les. Y-1 FMSI 06085 Results to date: Table I shows the levels of asbestos found during the most common operation of brake-lining m~intenance. When a brake lining is brought into a repair shop for inspection or replacement, the wheel is removed and all loose dust is removed from the drums and back plates by means of a compressed air jet. The cloud that is produced is visib~e, and remains so for minutes afterward. There is minimal, if any, effort to control dust in most garages and workmen very rarely wear respirators. Table I shows that fiber counts are high in the operator's area, and that there are moderately high concentrations at least 20 feet away. Background sampling during the same operation shows that immediately after jet air blowing and for at least 14 minutes afterward, there are measurable concentrations. These measurements were taken at varying distances from the operator (from YO to 75 feet) and show that other people within that perimeter are exposed, including mechanics, shop.management, salesmen and customers. Ten samples of brake drum dust were processed for electron micropsopic examination without changing the size distribution, and asbes~os fibers present in the dust were measured. The results are shown in Table II. It was found that most fibers are too small to be seen by optical microscopy; almost all of them were shorter than 0.4~ in leng~h. Virtually all were of respirable size. Prior to this study, it had been generally accepted, on the basis of l~m ited data, that asbestos brake-linings are thermally altered to an inert, presumably harmless dust, during braking action. Our observations show that asbestos fibers do survive. This has been found in every brake drum dust sample analyzed by x-ray diffraction, electron microscopy and microchemical scanning electron microscopy. Table III and IV present data collected during brake lining maintenance operations at the New York City Department of Sanitation truck repair ~hop. Two important operations are performed in this large shop for reasvns of FMSt 06086 t l economy-grinding and bevelling of linings, otherwise generally performed during manufacture. Accordingly, these studies relate to levels of asbestos exposure experienced by workers engaged in manufacturing. New linings are ground to remove imperfections on the surface and used linings are salvaged by grinding the surface ~o remove grease and dirt fiber concentrations experienced during grinding ranged from approximately 2.0 to 7,0 large (optically visible) fibers/ml of air (2xl06 - 7xl06 /m3 ). The background or area samples for this operation ranged from 1.2 to 0,2 fibers/ml (1,2 - 0.2 x 106 /m3 ) with a general decrease with increasing distance away from the operator. From six to ten other mechanics would thus be exposed to perhaps about one fiber/ml, A concentration of even one fiber/ml is equivalent to inhaling 8 million large fibers per working day, those longer than 5~. Much larger numbers of shorter fibers would simultaneously be inhaled, Table IV shows fiber concentrations measured during bevelling of new truck brake-linings. The lining edge is bevelled on a grinding wheel, so that the brake will grip properly. Concentrations were very high, ranging from 32 to 72 fibers/ml, and background counts were measurable up to 30 feet away. Significance: The data indicate that, during brake-lining maintenance and repair, workmen in garages, service stations and brake repair shops are exposed to asbestos and thus may be subject to serious cancer risk. Others, at some distance from the repair work, are perhaps subject to the same hazard, These environmental measurements will be of value in considering the health experience of brake-lining repair workers, as a background to evaluation of the importance of asbestos from brake-linings as a factor in general community asbestos air pollution, Publications: To be published. FMSI 06087 Investigators: A. M. Langer, Ph.D., A. Rohl, Ph.D., Mary S. Wolff, Ph.D. Support: Health Research Council: U-1272. Research Fellowship Award - ES 02565 Career Scientist Award ES 44812 Period: 1973 ~( I 2, FMSI 06088 .. Table I PERSONAL SAMPLES - AUTOMOBILE BRAKE SERVICE Operation Distance Concentration (fibers/ml.) * Blowing dust out of drum brakes .."II "" " ... " " " " " .. " " II II " . " "II II II ..... .. ...." " .. " " " II " " " "" " " ... .. .." " If ...3-5 ft. n' .5-10ft .." 10-20ft. ..13.8 29.4 6.6 13,6 3,8 2.0 4.2 0.4 4.a BACKGROtTh1> SAMPLES AUTOMOBILE BRAKE SERVICE O,eeration Blowing dust out of drum brakes " "" "II II " " "II II' II " " "" " " .. ." " "II II II " " II II Distance from 02eration 10 ft. 20 ft. 12 ft. 50 ft. 65 ft. 75 ft . Time Lapse 0 min. 0 min. 5 min, 5 min. 7 min, 14 min. Concentration (fibers/ml.) 0.3 . 0,8 0,2 0.1. 0,1 0.1 Only fibers longer than 5~ ~ere counted, by.phase microscopy at 400x. FMSI 06089 \ SIZE DISTRIBUTION OF CHRYSOTI.LE FIBERS IN BRAKE DRUM DUST Fibers counted and sized at 42,000 X (all fibers have diameters from 250~ to 500~) Sample 750-1500~ 1500-22505t 2250-30oo5t 3000-3750~ Total 1 "40% 34% 11% 11% 96% 2 32 23 32 87 3 20 25 25 70 4 26 37 26 7 96 5 57 17 4 78 6 23 9 12 12 56 7 50 26 21 2 99 8 29 30 21 17 97 9 6 41 18 10 75 10 11 6 31 31 79 . FMSI 06090 PERSONAL SAMPLES - TRUCK BRAKE SERVICE Operation Renewing used linings by grinding " " " II " " "II II II " " "" " " " " II " " " "" " " " "II It " " "" " " " " II " " II " . " " Concentration (fibers/ml.) 2.7 7.0 2,2 4.1 5.0 4,7 5.6 1.7 2,5 2,0 ..____.-..-.._,.._-:- BACKGROUND SAMPLES - TRUCK BRAKE SERVICE Operation Distance Concentration (fibers/ml.) Background to grinding used linings " "" II II " " "II II " " "" " " " " II II 10 ft. 10 ft. 25 ft. 25 ft. 60 ft. 1.2 1.7 1.0 0,6 0.2 FMS' 06091 PERSONAL SAMPLES - TRUCK BRAKE SERVICE Operation Concentration (fibers/mi.) Bevelling new linings " "" " "" " "" "" It 31.7 23.7 32.7 72.0 26.3 BACKGROUND SAMPLES - TRUCK BRAKE SERVICE Operation Distance Background to bevelling linings " "" " " "It " " "" " 8 ft. 12 ft. 12 ft. 30 ft. Concentration (fibers/mi.) 0.6 0.5 0.3 0.3 ~ FMSI 06092 PERSONAL SAMPLES - TRUCK BRAKE SERVICE Operation concentration (fibers/ml.) Punching rivets into brake lining " " "" " Chipping rust off used brake drums Sweeping floor around grinder Background taken 15 ft. away during sweeping 1.9 2.0 2.4 3.6 3.1 FMSI 06093 RECOM}:Umm (:mn:RIM) PROCEDURES FOR ASBESTOS J1Ri1.KE A.' CLUTCH SERVICING The National Institute for Occupational Safety and Health (NIOSH) has research underway concerning dust exposures during brake and clutch servicing. Due to preliminary data demonstrating significant asbestos exposures during presently used brake and clutch servid.ng techniques, NIOSH has reviewed alternate techniques whereby asbestos exposures are reduced. The followtng are interim procedures recommended by NIOSH to minimize dust exposures. l. If possible. an area shall be designated for all brake and clutch repairs. Entrances into this area shall be posted with an asbestos exposure warning aign as follows: Aebestoa Dust Hazard Avoid Breathing Dust Wear Ass:tgned Protective Equ-tpment Do-Not Remain in Area Unless Your ~ork Requires It Breathing Asbestos Dust i'iay Cause Asbestosis and Cancer ~. Duri.ng brake servicing, an oi.r purifying respirator, either single use or with rerla<:eable particul.at:e filter{s), as aj:>proved by the Minir.g Enforcement and Safety Administration (formerly Bureau of Mines) or NIOSH. shall be worn during all procedures starting with the removal of the wheels and including '(eassembly. During manual clutch servicing, s\Jch a respirator shall be worr, during removal and cleaning of the clutch, pressure plate and housing assembly and during installation of the new clutch assembly. S. Dust shall first be cleaned from brake drums, brake backing plates, brake assemblies and clutch assemblies using an industrial type vacuum cleanex equipped witn a high efficiency filter system (>99~ efficiency for 0.3 vm diameter aerosols). After vacuum cleaning, any remaining dust shall be removed using a rag soaked in water and wrung until nearly dry. Under no circumstances shall compressed air or dry brushing be used for cleaning, 4. During arcing and ri.veting operations, an approved respirator, as d~scrib~d in {2) above, shall be worn. Grinding (arcing) machines shall be provided with lotal exhaust ventilation such that ~orker exposures are maintained at least below the 1976 OSHA asbestos standard (29 CFR 1910.1001).* At a minimum, the dust'bag of the arcing machine shall be rc!uovcd and replaced with the hose of the. high efficiency industrial vacuWX~ deocribed i.n (l) above. FMSI 06094 -2- 5. Industrial v.:~cuum ch~~:mcr haga containing asbestos dust and cloths used for wiping brake and clutch assemblies shall be sealed in plastic bags and labeled with the following warning label printed in letters of sufficient size and contrast to be readily visible and legible; Caution Contains Asbestos Fibers Avoid Breathing Dust Breathing Asbestos Dust May Cause Asbestosis and Cancer All asbestos waste shall be disposed of in accordance with the OSHA asbestos regulation. 29 CFR l910.100l(h). During removal of vacuum bags, an approved re.spirator as described in (2.) above, shall be worn. 6. All floor cleaning in areas where brakes and clutches are repaired shall be done with the high efficiency industrial vacuum cleaner as described in (3) above. Grinding (arcing) machines shall also be cleaned with such a vacuum cleaner and.any remaining dust wiped with a damp cloth. An approved respirator, as described in (2) above, shall be used during this cleaning. 7. Although adherence to the ab~ve procedures should minimize any contamination of work clothing, it is required that the appropr:tate portions of the OSHA regulations on asbestos (29 CFR 1910.1001 (d), (3 and 4)) concerning special clothing, change rooms, etc. be followed. NOTE: St~ict adherence to the above procedures dhould minimize exposures to mechan:i.cs during brake and clutch servic.ing. These are interim recommendations and are subject to revision pending results of ongoing NIOSH research. Section 1910.1001 of the Code of Federal Regulations was formerly Sc~tion 19l0.93a. This change was noted in the Federal Register, May 2S~ l975. Prepared By Division of Field Studies and Clinical Investigations National Institute for Occupational s.~fety. and Health Cincinnati, Ohio FMSI 06095 MOTOR 1790 Broadway, New Thrk, N. Y. 10019 ROBERT J. CERULLO CONTIUBUTING TECHNICAL EDITOR 1851- 60TH STREET, BROOKLYN, NEW YORK 11204 March 30, Iq77 To; E.VV.Crislone Your in good company E.W.since as you wi I I see on the attached sheet the Notional Institute for Bccupotionol Safety 00d Health uses the word breathing in their Recommended Procedures for Asbestos Broke and Clutch Servicing. FMSI 06096 RECOMMENDED (INTERIM) PROCEDURES FOR ASBESTOS BRAKE AND CLUTCH SERVICING The National Institute for Occupational Safety and ;~~.~reaearch underway C'oncPrning dusr exr>osurLs d'l' !,'--. .'.":t,.h:>(nNl IO,-S1.H11)1-<hh as August 6, 1975 -2- 5. Industrial vacuum cleaner bags containing asbestos dust and cloths used for wiping brake and clutch assemblies shall be sealed in plastic bags and labeled with the follO\ving warning label printed in letters of sufficient size and contrast to be readily visible and legible: Caution Contains Asbestos Fibers Avoi~reathi~ust Breathing Asbestos Dust May CausOsbestosis and Cancer All asbestos waste shall be disposed of in asbestos regulation, 29 CFR 1910.100l(h). bags, an approved respirator, as described accordance with the OSHA During removal of vacuum in (2) above, shall be worn. 6. All floor cleaning in areas where brakes and clutches are repaired shall be done with the high efficiency industrial vacuum cleaner as described in (3) above. Grinding (arcing) machines shall also be cleaned with such a vacuum cleaner and any remaining dust wiped with a damp cloth. An approved respirator, as described in (2) above, shall be used during this cleaning. 7. Although adherence to the above procedures should minimize any contamination.o portions of the f work OSHA r clothing, egulations i ti on sa srbeeqsut oi rse d( 2 9t h~aFt R t he appropriate 1910.100l(d) (3 and 4)) concerning special clothing, change rooms, etc. be followed. NOTE: Strict adherence to the above procedures should minimize exposures mteon.m'aetic.hoan~n.icsandd uring are brake subject and to clutch servicing. These revision pendjng results are interim recomof ongojng NlOSH research. Sect l.un l <J l 0, l 001 of the Cc-1 c yf Y:d_I'_L d __l_:, ~.:;u_l_ci_t_~~l_l_1_s \vas f orml'l 1, Sectlonl9LU.LJ.\a. This ::han(~" \J,L. w>ted \11 the Fc~dernl Registor, Nay '1 q '(') 19 I';. Vrep,!rtLi ':y Di\~:~._ion ,f i'i(l.. l ''t1~(1ic:-: at:d Cl~i1il:<il 1nve~-.tigations !'hi ic'll<d lu.,' it'''' t<;r U~,1 1 . i<i't:l '~:J:t ,. . 111<l He<el.th ~in,~i_;rnnti, tll\io FMS\ 06097