Document mmLLLEvQMKYM58x4D3nNwOdeb

\\ Revised Dral: -- -i/l.r,/TO (3rd Major Revision) ut. k rtn CRITERIA AND RECOMMENDED INTERIM STANDARD FOR PREVENTION OF A5BES7GSIS O, f ,`S di J *! 1 ? Jrva* rr...V' CJ C" c: c* UJ O f-- f -- Oo 1. O. S. DEPARTMENT OE HEALTH. EDUCATION, AND WELFARE ' Public Health Service Environmental Health Service ` Bureau of Occupational Safety and Health Cincinnati, Ohio 7 BB 0021416 this document was NT o^aoRDROF r !g ^SfcSe kuTHEN fICA i ED PX PP.G INDUSTRIES. INC. 3008 t \JL V . rrt*4 f'fJ* _4t^4 H V Industrial experience- ias proved the need for criteria and standards W to protect the health of workers exposed to an ever increasing number cf r potential hazards at their workplace.' In order to provide relevant data from which valid criteria and effective standards could be deduced, the Bureau of Occupational Safety and Health has projected a formal system of research with priorities determined on the basis of specified indices. It is iutendvd to presmr. successive reports as studi-ss arc completed and standa ds are sufficiently crystallized so as to be feasible. The first report, which follows. concerns asbestos. Other reports will follow as the research and evaluation progresses. AU standards will be reviewed periodically in the lighr of additional data as research continues to keep protection of die worker's health as effective as, the state of our technology requires. 1 am pleased to acknowledge the contributions made by members of my staff, who developed this project, and the valuable constructive com ments made by the Review Committee on Asbestos. A list of theso contributors and reviewers appears on pages 11 and ill. * i f-0 L'.' V*' rr yi urn f" ^ o IU o oo 11*- Marcus M. Key, M.D. Director, Bureau of Oc onal _____ -- Safety and Health J'bT 0021 422. Environmental Healtli Service I* THIS DOCUMENT WAS NOT A RECORD nr irs filesSaTnd l'TM Z' DID not C0ME FROwi i 3S09 review committee on asbestos Mr. Edward jT Baier Director, Division of Occupational Health Pennsylvania Deparfuier.: of Health P.O. Bex SO . Harrisburg. Pennsylvania 17120 W. Clark Cooper, M. D. Professor of Occupational Health in Residence School of Public Health University Gf California Berkeley; California S4720 Paul Gross, M.D. Research Professor of Pathology of Industrial Diseases Graduate School of public Health University of Pittsburgh Pittsburgh, Pennsylvania 12213 Morris Kleinfeld, M.D; Director, Division of Industrial Hygiene New York State Department of Labor go Centre Street New York. New York 10013 Douglas H. K. Lee, M.D. Associate Director National Institute for Environmental Health Sciences P.O. Box 12223 Research Triangle Park, N.C. 2770& Mr. John C. Lumsden Chief, Occupational Health Section North Carolina State Board of Health Raleigh, North Carolina 27602 RaymondT. Moore, M.D, Assistant Commissioner, Environmental Control Administration, CPE, DREW Washington, D. C. I. J. SeUkoff, M. D. Professor of Environmental Medicine Mt. Sinai School of Medicine City University of New York New York, New York Georgo W. Wright, M.D. Head, Department of Medical Research St. Lukes Hospital Cleveland, Ohio BOSH REVIEW COMMITTEE AND CONTRIBUTORS Mr. Howard E. Ayer, Assistant Director, Division of Epidemiology and Social Services Mr. Dohrman H. Byers, formerly* Director. Division of Occupational Injury-and Disease Control Mr. Andrew D. Hosey, Director, Division of Criteria and Standards Development Mr. Richard E. Kinser. Laboratory of Physical and Chemical Analysis | BB 002141 I 00 I JMENT AS N0T A EC0RDr0F . ^canS^be^the^t^eo sinUSTRlES, INC. 11 * 3010 Mr. JohnV. Crable. Acting Chief, Laboratory of Physical and Chemical Araiks is Mr. Cobby F. Craft. I>-*puty Director, Division of Occupational injury and Disease Control Lewis J. Craliey, l'h.D., Director Division of Epidemiology ami Special Services Lcrice Ede, Review and Rucjuiremer.ts Analysis Mr. Jeremiah R. Lynch. Chief, Laboratory of Engineering George W. McCarl, M. D., Occupational Health KepreSetuitive. Regica3 1 and 11 Mr. Roger A. Nelaou, formerly uf the Division of Criteria and Standards Development Warren L. Smith, M. D., Acting Chief. Medical Services Branch Herbert . Stoicnyer, Ph. D., Chief, Laboratory of T rodeoing;, and Pathology r:> cn L'-l -jt-n a-**.- 1 : Bobby j. Cunter, Tli.D., Assistant Director, Division of Criteria and Standards Development * Mr. John L. Holla, Laboratory of physical and Chemical Analysis Mr. Clca W. Sutton, Chief, Technical Assistance Eranch i-. * ' 5 * V, J TM Cfr'r ) 3^-*' C) o ->2 C_ i ' ' fdi `Vi f-.T j o L-.ll ~ -J ' ic nnHIMENT WAS NOT A RECORD OF 3 INDUSTRIES, INC. 010 u ,^'f'nc^D S FILES AND CANNOf BE mOI ncfiLAi tD PPG INDUSTRIES, INC. i.^^002 !^| g"J U1 32H CRITERIA AND RECOMMENDI! I) INTERIM dlA.t*tViiSW* ritiAJ ffiiFUi'# t ** 4 t AJ|4hf Ut aw4 Cw<i<IW'C4H'V/NV*!l*il Table of Contents PREFACE ; ............................................... t CONTRIBUTORS -AND REVIEWERS INTRODUCTION........................................ RECOMMENDED INTERIM STANDARD REVIEW OF PROBLEM........................... U*s *f Ami Exposures to Asbestos Early Indication o: Hazard Medical Aspects of ASbcstwSis . . DEVELOPMENT Or STANDARDS . RaiiiTor Previous Standards Basis' for Proac-aed Standard METHODOLOGY Air Sampling Methods principles of Sampling' Collecting Sample . Mounting Sample . . Evaluation . Analytical Methods i U 1 3 4 t--^ TO 4 -'TM '.I i*.-' _J 9 10 'Y 14 r>,, 1G ""A 21 me' 22 22 23 o r^J 26 27 O o 29 "-J* ~ ^ 29 CONCLUSION 30 REFERENCES ....... APPENDIX; ANALYTICAL METHODS X-ray Diffraction-- Internal Standard X-ray Diffraction - E.domal Standard Infrared Spectroscopy . . Differential Thermal Analysis * . - Atomic Absorption Spectrophotometry References ............................. ... . TM'^rDrNOTc&0^ "S SSnS&MK AUTH6NTWM BYPPG INDUSTRIES, iNC. u' vn '. . <* 32 33 33 3S 43 44 43 | BB 0021420 | iv rr ;*<- 3212 r*t  1 INTRODUCTION T This Report, tlw firs: in the projected series of documents, presents % the criteria and recommended interim standard which wore prepared to 4 a 5 meet the need for preventing asbestosis. The necessary relevant data are also made available for use by the Secretary, Department of Health, Education, and Welfare in accordance with provisions in the proposed Occupational Safety and Health Act requiring the development of criteria by "The Secretary. Department of Health, Education, and Welfare.. .on the bn-ijs of such research, demonstrations, and experiments and any other information available to him.. .** cr:? v: CJ~ The Bureau of Occupational Safety and Health, after a review of all data and consultations with others, formalized a system for the devel opment of criteria upon which standards can be established to protect the V* - C' C" H 1 . C =Vi C00 health of approximately SO million workers from exposure to hazardous chemical and physical agents. Priorities iu this system are based on five * indices: (l) the number of workers potentially exposed; {-) the relative j-l.--i toxicity index of a particular substance or physical agent; (3) the inci dence of illnesses (or death) ;'(4).tha quantity of the substance produced * * ** and used.in the United States^-and (5) the Increase or decrease in the ; quantity used over a period of years. J_BB_021 42 1 I THIS DOCUMENT WAS -NOT A RECORD *0F PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES.AND CANNOT BE AUTHENTICA1 ED BY PPG INDUSTRIES, INC. 3313 4&JL 0- 2 In addition to the above* system, the jud^nents of industrial hygienists * fr-vn 10 State agencies and 25 private industries worn considered in est-tbiishi-j,; a teniaiiw pr.uruy list for over 00 chemical and two physical amenta. * Afl RECORD OCCURS SSDDADj^cA? uovJ F\t^ '2 O o J BB 0021422 | 3214 3 RECOMMENDED INTERIM STANDARD The Puphc Health Service recommends that occupations? exposure to asl<5tr*s i dual ?k- controlled so tliat nu worker shall be expand to more than 3 asbestos fibers per milliliter based on a count of fibers greater than. 3 microns (u) in length as de termined by the recommended method, which is described in this report, and based on lime-weighted average exposures for a 40-hour work week, (Sec p. 24 for defini- ,* Hon uf a fiber.) Concentrations greater than 5 fibers/ml, but not to exceed 1-0---f--i-b-e--rs/ `>1* v ml. mav be permitted for 1 ."-minute periods each hour/ i to five times daily... ijJJ <> -4- 'Ce N> Tise interim slamiard recommended is leased on recent investigations by the Public Health Sendee and the Commonwealth of Pennsylvania and on the fexj^r; Os ^* v V-i bpinio:ts of the Review Committee on Asbestos. It will bo subject to review ir. 1&72 -"i 'I * ^ ^hnd will be revised ns necessary. . t * *t \ r-v-* ' '- .it ' t'.Lrj This interim standard was developed to'meet the following criteria: : ^V*\ *v* 1- Ir will prevent asbesiosis in nearly all workers exposed over a working lifetime, `v Ov ^ *** ly a: 2. It utilizes techniques that are valid, reproducible and available to industry and -\* \vkf`* ofiicial agencies. \5* . t; vit V, 3. its attainment is> feasible with existing technology. Xv. It should be clearly understood that this interim standard Is intended to prevent O c; o o CO 'St, C UJ CJE> f*" o o" 2: asbestasis. Although it would be expected to reduce tfic risk of neoplasms, its adequacy in this respect cannot be assured because of insufficient knowledge on dosage--response relations and the influence of different -typei of asbestos and co-factors. A second document dealing with criteria and standards for neoplastic effects will be forthcomjng. fle tttintvT ci a, r<(*is.'ii etie ^ -- h'. i 14 MV. 6,\C7' J-Jr./i itt heul-evc.i. l*t- J . -L (>. t**.r ~ (i : - ^_____ -- ^ W C*'1* ^fn* * *w .THIS DOCUMENT WAS NOT A RECORD OP . PPG INDUSTRIES, INC. DID NOT'COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED " ' 'BY nPG^IEiU.'yTriLtGj WO,. ,, ' ' "nr ^ .------- - 331.5 ' 4 REVIEW OK PRORLKM Asbeitos is a generic term that applies to a nujnixrr of mineral silicates incoinuustible in air and separable into filament*. The most widely used in industry in the United States is chrysotiic (liMgO dSiO.^ 211-.0) a fibrous form of serpentine. Other types include amosiu* (3MgO HFcO </3 lGSiO., ?1I.>0); crocidolitc (Na.,0 3FoO Fe^O^ SSiG;> 11.^0); truinolite /_ Ca (SiO-j)., _/; anthophyllUe /_ (MgFe)7 Si= k--* * 1 O and actinolite / Ca(Mgre)-j (SiO-)4 _/. Uses of and E.viOaures to Asbestos Almost one million tons per year of asbestos are used in the United Sates. In 10B5, approximately 74 percent of the asbestos produced was used in the construction industry (522,200 tons) and 26 percent in non-construction industries (IS7,400 cons).' Approximately 92 percent of the half million tons used fn the construction industry is firmly bonded, i.e., the asbestos Is "locked in" in such products as floor tiles, asbestos cements, and roofing felts and shingles; while the * remaining $ percent is friable or in powder form present in insulation materials, asbestos cement powders, and acoustical products. * As expected these latter materials generate more airborne fibers than the firmly bonded products. The 1V7.400 tons of asbestos used in 1 TH1S DOCUMENT WAS NOT A RECORD PPG INDUSTRIES, INC. DID NOT COME FR IT S FILES, AND CANNOT BE AUTHENTICA1 BY PPG INDUSTRIES. INC. . 3216 uv 4 n f 'T.' non-construction industries in 13G5 wore utilized in such products as i \ asbestos textiles, friction materials including brake linings, and clutch / facings, asbestos paper, paints, plastics, roof coatings, and miscellaneous other products. Recently the construction industry has begun the application of asbestos insulation materials by spraying. While this technique at * present utilizes only a small percentage of the total asbestos produced, , -4 ....5 its use is increasing rapidly. It lias been found that more asbestos fliers become airborne from this method of application than from the older conventional ir.etm-ds. Mining and milling of asbestos iu the U. S. is a stnn.il industry employing fewer t'naa a thousand workers. In ar. unpublished Public Health Service survey of four asbestos mines and mills, mean exposure levels of 3 fibers > 5^u /ml In mining and 7 fibers > 5^u/ml in LU ft rs Vi * - o O \ ' j '- milling, were found. However, peak exposures were as high as 25 fibers > S u/ml. * *\ Recent levels oi asbestos exposure In the manufacture of asbestos 2 products are given in Table I. as rounded geometric means; arithmetic means would be somewhat higher. The data represent general plant averages by operation even though some Individual exposures were much higher in poorly.controlled operations. J'BB 00 21 425^2 THIS DOCUMENT WAS NOT A RECORD OF me In coSTKiE3' ,NC' D:D MT'COME FROM Lv tSh s AND CANNor BE authenticated BY PPG INDUSTRIES, INC. ,, .. 3217 wv * i 6 TABLEl Asbestos Concentrations by Ope ration2 (Fibers > S^u per ini) Geometric Means Operation Hi chest* Second Second Hichest* Lowest * Lowest Textile I'il>er pTop. Carding Spinning Twisting Weaving Friction Mixing. Coating. Extruding Forming Hot Pressing Grinding Sanding Cutting Drilling Inspecting Packing Cement Pipe Warehousing Mixing Pipe Forming Pipe Finishing Coupling Finishing Shingle, Mill Board, Casket Warehousing Forming Finishing 11.37 9.28 11.22 14.03 11.97 3.37 C.70 8.39 6.40 *10.04 4.09 4.29 2.11 4.09 2.92 H.ll 0.92 2.61 10.26 9.17 7.74 4.52 2.96 3.32 3.11 2.85 4.S7 3.20 4.63 5.50 1.48 4.06 9.53 * * 0.75 2.55 1.40 2.47 1.69 O.SO 0.65 0.40 0.73 0.47 1.26 1.22 0.83 0.58 1.23 m 3.02 0.77 1.02 0.55 O.Cb.... * - .1^^, " - /- vl 0.10 . 0.32 1 0. Go S :. . j 1.22 - .1 0.83 O A . - ,* * ( *) 0.92 s " HTM OO 3.20 0.9U 2.95 Insulation Mixing Forming Finishing Inspecting Packing . 77.96 20. OS 49.52 13.10 46.96 21.82 27.9" 13.21 9.54 2. 57 5.42 2.73 1.05 0.44 0.57 0.41 * As determined by overall plant average concentrations. \ a document was not a record of i INDUSTRIES, INC. DID NOT COME FROM j FILES AND CANNOT BE AUTHENTICATED PPG INDUSTRIES, INC. !)W 3313 T rnrw ir C: Recent (lOCO-Cr) data from Pennsylvania* in two asbestos textile plants show averu^p dust concentrations in carding of 3. 5 mppcf and weaving of 0.3^ % mjpwf. which arc approximately equivalent to 17.3 and 3.4 libers -'ml respec tively. in ur.c- plant, in twisting the average concentration v.as 2.3 mppef or 11.3 filKTs/ml; in ti.e other plan* spinning was 1.6 nipper or i fibers/ml. These concentrations arc in general agreement with the results for textile op-rations presented in Table I. Uttle data are available on the exposure c-C insulation workers, other asbestos product users, cr other workers with secondary exposures such as cbCstruetiun wcrlters. Baluer and Cooper3 reported mean exposure levels of 3-0 fillers > 5 u/ir.1 with peak e:<posures greater than 23 fibers > 5^u/ml for various operations in the handling of .asbestos insulation. These workers, however, did not spend all of their time working with asbestos insulation, and, consequently, time-weighted average exposures were lower. ( - .-J There are approximately 40,000 insulation woriters in the United States who are exposed to asbestos dust. The activities of these workers - cause secondary exposures to an estimated three to five million other /5 building construction and ship.Insulation workers. .The dust closure of s-/ the individual worker is extremely variable. Because of this variation and the small number of asbestos workers at any one location, the asbestos dust exposures of theso workers have never been satisfactorily estimated. O :M ' '* */ *4 "^ o o o v THIS DOCUMENT yjAS HOT A ^"RR0M Sid caSot.be authenticated by PPG INDUSTRIES, INC. __ ____ ____________ ^__ "j ~QQ~ 00 2142_i 3219 An An estimated SO, 000 workers are involved in the manufacture of \ asbestos containing products. This figure does not include secondary / manufacture of products which contain asLestos, as electrical or thermal insulation, or products which include previously manufactured components containing asbestos. 5 The following information, furnished by the Pennsylvania Division of Occupational Health, shows the number of plants using asi/cstns in which potential exposures can occur. These figures are based on a total of IS, 42s manufacturing plants i*. that State as of August lP0;i, and represent al>out X.4 percent of all manufacturing operations in Pennsylvania. Service facilities such as garages are not ( \ included. Insulation, including cutting, drilling, and tape manufacture Manufacturing and processing Brakes aiul friction Cement, clay Miscellaneous* Caskets Signs Safety Equipment Laminated Material Paint and Roofing Materials Shipbuilding and Shipbreaking Impregnating Resin and Urethane Textile .*.* % Undercoatir.g Material .Ironing Board Covers Flooring i 75 | BB 0021428 | CUMWJ co"e FROM s' INDUSTRIES, INC. 3220 \ 9 indications .>f IMud of Hazard m a. a x The widespread u^e ni nsl*.-:>tus fibers did n<>t begin until the last ;c quarter of the nineteenth c*:.,.ury. As a result of the increasing use of asbestos rr.jncrul.-.. tliure las Ixiun an undureurrunt of concern over their role as factors in human disease. To interpret accurately the biologic actions asbestos, it is imperative that the character of the exposure as to concentration, size, and type of fiber must be known. Data of this nature- are scanty or often r.on-uxistent at present with resiiect to human exposure.0 The first record of a case of asbestosis was made by 7 Montague Murray in 2906. The first complete description of asbestosis -J and of the "curious bodies'* seen In lung tissue appeared In 1927 when Cooke,6 and McDonald9 each reported on the same case of asbestosis and McDonald's report included another case. Each author gave reasons for believing that asbestos'bodies originate from asbestos fillers that . !o <o OIp ^, - reach the lungs. A majority of people exposed to asbestos dust develop the disease "asbestosis" if thu dust concentration they have been exposed to is high and the duration of their exposure is long. This has been docu mented by the following studies: Merswether and Price, 1930; 10 Fulton e: al., 1933; and Dreessen et aU, 1938. In 191b Hoffman *m reported tbit it was the practice of American and Canadian insurance companies not to insure asbestos workers on account of the assumed 02| 029~| health-injurious conditions of that Industry. About the same time uie DOCUMENT was not a record OF P(f INDUSTRIES, INC. DID NOT COME FROM PS FILES AND CANNOT BE AUTHENTICATED IY PPG INDUSTRIES, INC. 3221 pju fT Pancoast.^Milltr, and Landis11 reported on x-ray appearances of pneumoconiosis in 13 Individuals exposed to asbestos. Mills* pub lication1" was the first report on nsbostosis published in the United 13 Suites, ar.d in that same year, 1930, Lynch and Smith reported on asbestos:* bodies* found in the sputum of asbestos workers. In Merwwcthvv's review of asbesto^is. 14 emphasis was placed or. the relation of al>cstosi$ to dusty working conditions. The clinical .aspects of asljestosis are well documented. Gloyne1* ctiCussed the pathology of ashestosis and methods for diagnosing asbestos todies and asbesiosis. Selikoff and Hammond1G .analyzed 1,575 autopsies in three large New York City hospitals and found asbestos bodies in 542 (47.7%). firoadly considered, 40 percent of housewives, 50 per cent of "white collar" males, and 50 percent of "blue collar** males showed asbestos bodies; while males who had : history of shipyard or construction work had a higher incidence of asbestos bodies, e.g., 90 of 129 cases or 70 percent. Seltkoff's obsexvatioas also suggest that asbestos bodies were as frequently present 35 years ago as now. The Annals of the New York Academy of Sciences presents an * excellent and lengthy documentation on the "Ufological Effects of Asbestosis.'*1 The Public Health Service, with the assistance * * "ferruginous bodies" is a more descriptive term. !-- J_BD 00 21430~7 THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. 3222 t ft rttr 10 of asbestos producers and manufacturers. is examining its findings with > 1,1 .<?" "N . population1 s exposed occupationally during th. e past 30 yea.rs__c'T) his /; ' .,*v 9" e v *' V A;.:c;,^'v* information should provide more definitive epidemiological knowledge *.'* \ \' v. ,v* _ .,v V- >*' as to the conditions necessary for the prevention and ultimate reduction * *i * of significant pulmonary fibrosis in workers exposed to airborne asbestos fibers. Medical Aaj'fccts of As'oestosis The occupational disease, ashestosis, is characteri/.ed by: 1. A pattern of x-ray changes consistent with diffuse interstitial ;^ fibrosU of variable degree and. at times, pleural changes of fibrosis f> 1 V. *> .j % * v V, N and calcification. 2. Clinical changes including fine rales and finger clubbing. These may be present or absent in any Individual case, 3. Physiological changes consistent with a restrictive lung disorder. > The diagnosis of asbestosis is further predicated upon a known L; >* L. history of occupational exposure to airborne asbestos dust, in general, considerable time must elapse between inhalation of the dost and appearance of x-ray changes. % Several clinical abnormalities appear to occur with unusual frequency in those environments where airborne asbestos fillers, often in association with other substances, exist. Of these, diffuse ______ I-iUL 0021431 |f. THIS DOCUMENT VVAq lurtT ,, PPG INDUSTRY iM^Sr,N0T A REC0rfD OF IT'S FILES AND CAN^nr10 WT CME FR0^ BY PPG INDUSLRiEs'^Jf'JC^ 3223 chronic inflammation and scarring of the lung, historically referred to 5 as "asbestosis," was recognized early in this century. Based upon the promise that a reduction in the number of fibers ir*haleti and retained in the lungs would lessen the severity or prevent the Occurrence of "asbestosis." efforts to decrease the "dustiness*' o: the worker's environment in s^me, though not all. asbestos milling or using processes begun in ti.c middle IWO's and early 1`t-iO's. The fact that a reduction in frequency and severity of asbestosis has been dcmc:.s:ratud in those work- ir.g places where iueh a program of dust reduction has been established, ** v . \ 17 re confirms the view that asl>estosis is "dose-r^la*tcd" tn.flbprs of asbesto*s# . - " i - -** Some, though meager and incomplete, numerical data relating . V2- V**. 1 * * _ TbAi clinical manifestations of asbestos;s to dose of asbestos fibers are now* S t'l - r available. An abnormality* occurring with unusually greater frequency in populations exposed to inhalation of asbestos fiber, is that of localized thickening of the pleura with or without calcification of these plaques. v., r> ' *'* > The failure to find these plaques, as a result of some studies of certain design in certain areas, in some persons taown to have sustained sub- LoM tpt ^ og slantial exposure to asbestos fiber; the seeming absence of a dose relationship; the occurrence of the plaques on a rather striking geo- ** graphic basis; and their association with other exposures such as to talc ,` . 7170021432 aiui mica make the role of the asbestos Tiber in this manifestation d.________ _ ----- difficult to understand. - THIS DOCUMENT WAS NOT A RECORD OF - DiD NOT COME FROM 3224 |t Hu 12 In the late 1910's, a frequency of bronchogenic cancer {Treater than m that occurring in the general population was observed in persons suffering 9 from asbcsloa derived from manufacturing of asbestos products. In 1DC-1. this greater frequency was also reported in a group of insulation installers who were exposed to several materials including airborne asbestos fibers, in contrast to populations exposed to these kinds of mixed environments, examination of populations exposed to a less complex array of materials other than asbc:.t'e>, as exemplified by the mining and milling of asbestos fiber, has shown either no greater or a lesser order of augmen tation of frequency of bronchogenic cancer. Although -the question remains ft*: debatable, there is evidence to suggest that a dose-relationship exists between the inhaled asbestos fibers and tlieir role in bronchial carcinoma. W 1/ The possibility that_cthcr co-existing agentg .{co-carcinogcns) .such as ' cigarct smoking and metallic cations, play a role in this overall carcinogenic relationship is strong. j SL "x~-\ i, i- <v An increased rate of occurrence of mesothelioma of the pleura or >v peritoneum was rvjxjilod in some populations in 195i and in subsequent years. The possibility that asbestos may play a role in this distribution O f"> has bcc-n raised. The failure to find, thus far, an augmented frequency \ of this particular tumor in some ocher populations exposed for similar , *. * - '' * pcrio'.ls to substantial concentrations of airborne asbestos fiber, raises * a doubt that asbestos per se is of necessity the responsible agent. , ------ ---- * ... ----002U3r7 r pwr- THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. r-rqp 3225 m e r \ Tims, white pruM'Ut data are nut uU.'t|u:uu to (letme uuinplelely the jn-oMenK it can be stated without hesitation licit a>(K-lusis, bronchi/genic cancer,/and mesothelioma constitute abnormalities that a threat to life and well-being and hence are to be prevented. Of these three conditions, cur current Ir.otvledge is most substantial with respect to the relationship, both etiologically and quantitatively, between asbestos fiber inhalation and the subsequent development of asbestoses. Our knowledge is quite mesrer with re a rvc t_t_.j._ these specific relaticnsidps. regarding bronchogenic cancer and mesothelioma-. Evidence in hand Indicates that past and current standartls for fiber concentration in the working places where asbestos fibers occur, though undoubtedly contributing to reduction of the severity and fre quency of the disease, have not prevented completely the development f~^ CO - V:l C-,: of asbestosis. The role of asbestos in mesothelioma is uncertain, and information as to its etiological and quantitative relationship to asbestos fibers are so lacking, that criteria for setting a standard at this_:irnc OV** which would prevent mesothelioma nre virtually non-existent. With \ . . .\ LU ------- ;---------------------------------------------------------------------------------------------- \\ a respect to asbestos and bronchogenic cancer, while scant pertinent \\ jV* t'' #, \\ dam do exist and more will be available in the near future, usable and; \ v>~ ' \ v`l' \ / \*t -Vv \ nteaningful criteria upon which to base a standard for asbestos in_lhe: / . environment do not now exist.* (/ : * Granted the need for a new standard, lf`ii is to be based upon | BB 0021434 | meaningful data and criteria, the standard must be based upon those A* THIS DOOUME WAS NOT A RECORD OF PPG I- lUUSTRiES, INC. DiD NOT COME FROM IT'S FILES AND CANNOI BE AUTHENTICATED BY PPG INDUSTRIES, INC. *V 3328 u criteria related to asbestos (pulmonary fibrosis) with the conviction'trial this will be a step in thw direction of lessening whatever carcinogenic influence asbustos fibers in the environment of the working place may ultimately be shown to have. . Of necessity, the criteria for the recognition of asbestosis during life an; tho*e of a clinical nature. While the historical alterations associated with asbestosis are known, no body of data now exists relating these anatomical ciianges in a reliable epidemiological manner to various envirunmental cunceutvations of respirable-siac-u fibers of asbestos. Tito clinical findings that have been related to patterns of exposure art*: (l) chauges to be observed in the chest roentgenograms and (2) physical signs of rales, rhonchi and clubbing of fingers. The influence of asbestosis ujxm pulmonary and circulatory functions has been-studied, but only o pq Q __ i now arc the effects of such influences in the process of being related, epidemiologies lly to parterns of exposure to asbestos fiber. Until the epidemiological relation is established, the criteria for prevention of asbestosis must be clinical.* I DEVELOPMENT OF STANDARDS Various criteria nave been used for categorizing the environment in terms of its dustiness in past years. Recent developments have made rn L*J >r S b_ -- fi.ai r r* ^ c: LV: ^ r film 'jj *= l"" o c.; lTM Oo it cicar*that. with respect to establishing a standard for prevention of_______ __ --! I BB 00 2143 5TM asbestosis in those working places where as!>cstos fibers exist in the ------ --i ' THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES; INC. ,, CSS7 T"l " "l<lF11 " ` mil .. I l'i iTM. II, IWI ................................... IS eiivirontneii. a method utilizing the capture anJ dirtc; estimation of fibers of asbestos'be utilized. In the pas: in the United States, the impinge-? method was utilized for evaluating'the dustmens of environments by count ing particles as well as asbestos fillers. Even so, it may be possible to extrapolate, with some degree of utility, current estimations of direct fiber count in a retrospective manner based upon previous counts by the midget impinger technique. . f \/ i \ * , \* s .V-` "'.V*'-* ,vA.v* ' ' ' *\ While there still exists the question of whether or no: different varieties of asbestos fiber may have varying biological effects, there is at this time insufficient information to justify treating one variety la a different manner thtn another with rospoct to setting a standard. The question has also beer* raised as to whether or not fibers less than ,-y -,-l L. S microns in length have any or equivalent biological activity ir* comparison to asbestos fibers longer than 5 microns. Current evidence suggests tint Ll~_ r ' hU It is the fibers lunger than 5 microns that are biologically active or that :.!r` the fibers longer than 5 microns faithfully mirror the numbers of those1 fibers shorter than 5 microns In terms of biological activity; therefore it is appropriate to use a count of fibers longer than S microns as a criterion for characterizing the environment. V ^s. O CO o PPGlNm^TM?<mS N0T A- REC0Ri) OF IT'S rii FS flrnE^: NC" D,D N0T cME'FROM IT S FILES AND CANNOT BE AUTHENTIC Aren BY PPG INDUSTRIES, INC. TiJEKTICATED Ts'T002A436_ 3223 ' ' le Thusm'* the inu-rim stamlard developed is ' .. bused upon the above criteria, recent cr.vicarjnvr.`-*ii data and iho available, though scan:, epidemiclogical s information. Basis fur Previous 5ar^!ards The first standard for controlling exposure to usbestu* das: was recent mended by D.-ues-encl al. 18 in liO.s following a study nf W1 employees in tour asbestos textilo pbir.ts where massive exposures occurred. A tenta tive threshold hrr.it for asbestos dust of .1 million particles per cubic foot (mppcf). determined by the impiuger technique, was recomniended. They NOTCOMEFf:GM i?G FILES found numerous woll-marl^d cases of pneumoconiosis where concentre.tiens exceeded 5 mppcf, but only three doubtful cases where concentrations were V under 5 mppcf. However, only five persons were exposed over ten years to . concentrations from 0 to 4.9 mppcf. None of the 39 persons exposed to concentrations below 2.5 mppcf showed evidence of asbestosls; but only six - of these had been employed more than five years. The study by Dreesscn et al. bad unavoidable limitations such as the fact that 333 of the 341 employees studied had worked less than five t. . years in these textile mills, only 68 were employed as long as 10 years, \ -* and only 2 for over 20 years. Furthermore, the average age of these asbestos textile workers was 32.1 years and only one of the four plants studied had been in operation for at least 15 years. I BB 0021Z_I THIS DOCUMENT WAS NO.T A RECORDOF PPG INDUSTRIES. INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED* BY PPG INDUSTRIES, INC. # t* 2229 t, Thus*, the first standard established was based upon limited dam. a condition recognired by the authors who stated that.. ."5 mppcf may be regarded tentatively as the threshold value for asbestes-dust exposure until better data are available." For several years, the American Conference of Governmental Industrial Hygienists' (ACGlli) Threshold Limit Value (TLV) for asbestos 16 dust was 5 irppcf. This limit was based on the study by Drveasen et al. and subif-Ciuenr invc-atigntions by others. However, in 1S6S ACCIH pro posed a lower TLV of 12 fibers/ml > in length or 2 mppef and. a still lower limit of 5 fibers/nil > 5u in UrtUO length 'i.i, .y proposed in 1670. , CD CO UJ f. -- 'D D- CL. Believing that the 5 mppcf tentative limit recommended by Dreessvn et al.. which tho ACGIH TLV subsequently adopted in 1943, was out of CaU, the Committee on Hygienic Standards of the British Occupational Hygiene Society reviewed medical evidence, results of recent studies made by the asbestos industry in the United Kingdom, ami epidemiological data from the United States. In 1968, this Cora- 17 mittee published Hygiene Standard? for Chrysotile Asbestos Dust. The following is a summary and the recommendation -contained in the report: :d ; ; CD ... jr-- .o TflK DOCUMENT was not a RECORDmOF S.NDUSTWES INC. Dio NOT COME FROM 3KS Z cannot be authenticated BY PPG INDUSTRIES, INC. ____________ - 3330 *** 0 itil " IS *'l. A.s Ions as there is any ni rhumo vhry&ocilc duti in thw work vnvifunmer.l llivti; u-.ay bo muiu- mh:i11 risk to hu-lth Nevertheless, it slmuld U: n ab/ud dial exposure u;< ;o certain limits van be tolerated for a lifetime without incurring undue risks. f > The committee believes thr.; a proi-ev and reasonable objective would l*e to reduce the risk of contracting asbes tos is to 1 percent of those who have a lifetime's exposure to the dust. By "asbestosis" this committee means the earliest uoinenstrablo effects on the lu.:gs due to asbestos. ' ll is proUtUe that the risk of being affected to the extent of having such early clinical signs will be loss than 1 per cent for an accumulated exposure of 100 fibre years per cm**. That Is. fer example, a concentration of 2 fibres pr cm3 for 50 years. ! fibres per cm3 for 25 years or 10 fibres j-ur cm** for 10 years. en CO -- t'J -.2 __ 1 i_L_ 'o "3. It is recommended that exposures which lie in certain ranges of dustiness be designated by categories c according to the following scheme: ^O DUST CATEGORY Negligible Low Medium High CONCENTRATION AVERAGES OVER 3 MONTHS (FIBRES/CM3) r. 0-0.4 0.5-1.9 2.0-10.0 Over 10. 0 ... 0 1"-- i---- oo "4. The levels are expressed in terms of the number of fibres per cm3 greater than 5 u in length as determined with the standard membrane filter method. Any other method can be used provided it is accompanied by appropriate evidence relating its results to those which \ would have been obtained with the standard membrane filter method. , X WAS * cOMEfSO^ r ;TW&S- 'NC` 1"* 19 "5. When it-is necessary to work intermittently in a "high dust'' area an approved mask should I/O wiirn. prmidvd that the concentration is no more than fG fibres j*.-r cm*' and the mask has lcen sliwn by test to he a good Tit prior to entering the area. Siiould the concentration exceed O'* fibres pur cmJ a higher smivinrd of respiratory protection should ! provided, such as a pivssuru-fed breathing apj-arutus. "Addr.neial recmninendatioie* *l. I; is recoin mended that whore practicable an up-to-date employment record card be kept of every person which iiuiibUtcn, every calendar quarter, the category or eateftorits in which he or she has been employed and in which ne or she is recommended to work. "d. All employee* exposed In risk should be medically examined in.*fore employment. periodic examination* should be made thereafter, annually. Notes "These hygienic standards are subject to review in the lighl of new evidence and improved methods of measurement. C'A T/*5 . UJ "The standards are, in our opinion, the best that can lw dragon from the existing data. These data are scanty and leased on factory experience of continuous exposure during wortdng hours. Due caution should lie exercised in applying these standards to utiicr lattcms of exposure. As far as possible the dust exposures have been estimated conservatively and. in particular. In tlie period 1D33-1950 the average hours of work were substantially greater than 40 per week. ..) "It U hoped to supplement the existing data in due course, when the standards will, if necessary, be modified. Thoso standards will bo formally reviewed in three years." It should bo emphasized* thamt the environmental data upon which the British standard was based, according to Holmes, were related to "fixe 00*214405 5 DOCUMENT VMS NOT A RECORD C INDUSTRIES, INC. DID NOT COME FROW FILES AND CANNOT BE AUTHENTICATED PPG INDUSTRIES, INC. .,, 3232 20 *1 tt sampler; talxn a=> n<.ar a pva;ble to the breathing r.or.-* of the worker."" In other words, these were; nu; breathing ;,whc sample-s collected by personal samplers as recommended in this document or as practiced generally in the United States. For this reason, the British standard is lower by a factor of aiiuut 1.5 than it would be had breathing zone samples L-.x-n collc*clt-J. This statement is based on studies made b}* the Bureau of Occupstj jiuil S i:V?y and Health and leferrw-d to in more detail in the sec tion. Vrir.ciplus of Sampling. For these and other reasons it is not lwi=iUu to corn jo re the British standard with that recommended here or with the t-.*rr-rrrACGili TLV. In lyC?, Bal/.er and Cooper3 reported asix-stosis among insulation CTi CO -- Lfj 1-- f5 L.'.i rr r ^ ' A'Ve/v* workers exposed a; levels not exceeding the time-weighted average of 5 mppef. In a recent unpublished paper, Williams, Baler and Thomas'* compiled data from Ue Pennsylvania Department of Health files on expos J) 'V *-* 'M 'kil J} "J> ure levels at various textile processing ope radons in two plants. The . data presented include results of dust concentrations from 1930 through - ,* 1967 in one plant and from 19-ia through 196a In the second plant. Even though controlled exposures were fur the most part below 5 m'ppcf and In - M-----------------------------3------------------ -- , bb 00^1441 1 j many cases below the 1966 ACGI1I proposed limit of 2 mppcf, . 6-i cases of asbestosis wero reported from these two asiiestos textile plants. The r THIS DOCUMENT. WAS NOT A REC0IQ pb'G INDUSTRIES, INC. DID NOT ITS ftU$ AND CANpOt Bl.AU fhEN BY PPG INDUSTRIES, INC. ** * 3333 * * 21 authors conclude tin:: "If usbvslosih is to be prevented, airborne asbestos dust must bt stringently controlled in the world ng environment. From these vbita a TLV of 'j inppcf would provide inadequate* protection and the /A i- (/ >; *. propoied-2 n.ppef may not bo subshu.uavd." (It should be* noted that 10 . (ii-eis/ml corresponds to less than 2 mppcf and that the interim standard recommended--0 fiberss/ntl would Ijo lee.; than 1 mppef.) Tima, considerable evidence exists indicating that prevention or ^ ^ reduction of the occurrence of usbestosis among workers, the ------ UU ,j concentration of asbestos fibers to which they are exposed must be reducd3T` There is at this time, however, only scaut epidemiological data O-- correlated with results of environmental exposures upon which a defini tive standard can be established. In Ido*, the Bureau of Occupational c cv. O t'" ry ~' ' :jdU 2--iu Safety and Health Initiated a study. scheduled-for completion-in 1972, to 3Z ^7; relate dust levels to which worker* are exposed to the incidence of asbes-tj'; |-- D `XjD Mi tosis. Exposures to trace metals, as well as to carcinogenic oils in O CjJL z asbustns dost, w*>i-ulso be studied because these may be important In the mechanism of causation of asbcslosis and cancer. Basis for Proposed Standard * The proposed standard of S asbestos fibers/ml, > 5^1 in length, * is based on the best available' information to date and includes a consideration of the British standard, which states that the probable risk Turn nncUMENT WAS NOT A RECORD OF IorSmniKTRIES INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED 1 1 _ ____ IMP v *-------- l--' 3334 *'o 57/ v' 22 of developing asbestnsis (from exposure to chrysolite) will he less than 1 percent for an accumulated exposure of 100 fiber years per ml (150 fiber years per ml based on breathing zone samples). This equals 3 fibers/ml for 30 years. 6 fibers/ml for 25 years, or 15 fibers/ml for 10 years-- based or. brentrtr.,; zone samples. Thus, even though it is not possible to 75 < C compare the British data (based upon exposures to chrysotile) with data Ji _ *'*" 34 collected in the Vciseu States ' where worlxrs v.cre exposed to various f T- t: 1 ~ y * types of asbestos, it is Wlieved that this limit wall reduce to an insignifl- --`V c~- cant risk the occurrence of-asbestosis among wor'uirs, even those who may cr. be exposed to asbestos dust for as long as 25 to 30 years. It must be em- V. ._ y l.-hasizcd, however.., that litis standard may not necessarily prevent neoplasirrar; ^" ***** ^e- *-- * Additional rtsearch ts needed before a second document, covering this ^ /* f (\ ..-subject,"`can be prepared Wcause of the many other variables and factors !; ^ ^^ c./' "j p V * `vW 0* imrolyed. ' / / \-.v - * / ..V- a*' .* j. . v Furthermore. until additional epidemiological and environmental data 'x.. ' ';/ \ become available, it is recommended that exposures to asbestos dust be -V V* ' v' maintained as much lower as practicable than the proposed recommended standard. V\ METHODOLOGY Air Sampling Methods 16 In the study of asl>estv>sls conducted by Drcessen ct al. midget Impinger count data wore used as an estimate of dust exposure. AH of * the dust particles seen, both grains and fibers * were counted since fo<& ______ -----* few fibers were seen to give at* accucrate measurement. The THIS DOCUMENT WAS NOT A RECORD nr 0,0 K0T cTM jPPB?.^^T.!E AUTHENTICATED i--***""" 3S35 *% resultir.g^couut concentration uus a measure of overall dust levels rather than a specific measurement of the asl^estos concentration. This method was satisfactory* at tliat time since exposures were massive and the control measures installed to reduce overall dust levels also reduced the asbestos dust levels. As dust levels were reduced, it became necessary to measure the biologically appropriate attribute of the dust cl-.-ud. At equal levels of overall dustiness, the concentration of asbestos could vary consid erably from textile manufacture (75-85^ asbestos; to insulation (o-lo'J asbestos). Furthermore, if the limit were lowered below the ci-. "ii b- ts: i' tr: 5 mppcf used previously and dust counts taken by the impinger technique, it would be necessary to consider the effect of background dust, which could 1m as high as 1 mppcf. A number of methods for measurement of asbestos dust C,, c: c. C/ v-.. 4 'J O Cd concentrations have l>een used in the Public Health Service's cpidemiolog21 ee 23 24 ical study of the asbestos products industry. ' * * Based on the c*. : .data, the preferred index of asbestos expusuro is the concentration of fibers longer than 3jx counted on membrane filters at 420M with phase contrast illumination. Fibers longer than 5 u in length are counted in preference to counting all fibers seen In order to minimize observer/ -"Brooii"-4- S CANNOT EE AUTHENTICATED ft INDUSTRIES, INC. , 3236 24 microscope resolving power variability. Furthermore, the British define 4* > a "fibre" as a particle longer than 5ji and having a ratio of length to 17 breadth greater than 3:1. This method has been adopted as the standard field sampling method by the Public Health Service. Based on results of samples collected simultaneously by the impingcr ar.u membrane filter methods in the asbestos tc.'o.ilc industry, a concentration of G fibers/ml longer than is approximately equivalent to 1 mppe:. 1; this relationship is used, the intended change in the Threshold Limit Values (TLV) adopted by the American Conference of Governmental Industrial Hygienists (ACGIH) of 2 roppef based on the im97 pinger mothtes is equivalent to 12 fibers/ml longer than 5^u. " Although Cl?, y* --i.- ' C'. <tf- -` the British have retrained from standardizing on a single method of measurement, recent measurements have been performed by a method essentially identical to the fiber count method described in detail below, and the British interim standards for chrysotile asbestos dust are stated in these terms. When exposures axe measured in industries other than asbestos .3 ...1 textiles, the asbestos fiber concentration is generally lower than 12 fibers/ml when the lmpinger concentration is at 2 mppef. Since the ACC1H TLV Is concerned with asbestos exposure. It should be considered exceeded only when the fiber concentration is over 12 filiers/ml as the dust being counted in ihe lmpinger may include cement, resin, and __ --1 non-asbestos materials. * .THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM Tra-ILfcJWIfl CTIINOI PC AUTHENTICATED BY PPG INDUSTRIES/INC! . ` .. . 3337 4 Principh-3 of Sampling A dust sampling procedure must be designed so that samples of actual dust concentrations are collected accurately and consistently. The results of the analysis of these samples will reflect realistically the concentrations of dust at the place and time of sampling. In order to collect a sample representative of airborne dust. which is likely to enter the subject's respiratory* system, it is r.cces- * sary to position a collection apparatus near the nose and mouth of the Q C/1 subject or in his "breathing zone." The concentration of dust in the air will vary, depending upon tlie nature of the operation ami upon the type of work performed by the operator and t'uc position of thu operator relative to the source cf the dust. The amount of dust inhaled by an individual can vary daily. * seasonally, and with the weather. In order to obtain representative, samples of workers' exposures, it is necessary to collect samples under varying conditions of weather, on (UfTurcnt davs, and at different times during a shift. h~ / "'t - v t-.:.~, The percentage of working time spent on different tasks will affect the concentration of dust the worker inhales since the different * * *t tasks usually result in different concentrations associated with them. The percentage can bo determined from work schedules and by ^ nB ____________ _ observation of work routines. \ Sow CANNO; Bt AUT^llCA t . 3S33 The daily average weighted exposure cun be dvicrrrunvd by u-'ing the following formula; (hourj >t code, task A) (hours X cone. ta.<!-: B) + Ktc. $ hours (or actual hours worked) The eeruviitrarioii of any air contaminant resulting from an industrial o|M.*nuion also varies with time. Therefore, a longer sampling time will lotler appropriate the actual average. With the following rucummcnded sampling procedure, it is possible to colletc samples at the workers' breathing zones fur periods of cE , r; ^7 j'- nir from l to s hours tnus permitting the evaluation of average exposures for a half or full t-hour shift--a desirable and recommended procedure. Furthenuvro, dust exposures of a more normal work pattern result from r the use of personal samplers.' Studies conducted by the Bureau of Occupational Safety and Health in several industries showed that results of. f-- j. i dust counts from personal samples exceeded Cose collected at fixed posi- tiens l>y a median tictor of 4. In the asbestos Industry this factor was 1.5. This emphasize* lieu samples should be collected as near as possiblu to workers' breathing zones in order to evaluate their daily exposures. Collecting Sample The standard recommended in this report was based on a modification of the .membrane filter method described by Hdwards and I.ynch. -s 27 Brwthing zone samples for count are collected on Millipora* type AA filters in personal samplers operated by battery powered pumps and worn by thu employees. The filters are contained in plastic filter holders and are supported on pads which also aid in controlling die dis tribution of air through the filler. To yield a more uniform sample deposit the filter holder fac e caps should be removed. ^/ Mounting Sample The mounting medium used In this method is prepared by (- dissolving (J. 05 g of membrane filter per ml of 1:1 solution of dimethyl phthalutc and Uiorhyl oblate. The index of refraction of tr.e medium c thus prepared is * 1.47. 'u _ -^`4* To prejviru a'sample for microscopic examiiattion, a drop of the 'o - tJ) mounting medium is placed on a freshly cleaned standard (25 mm x 75 mm) - }-- >o microscopic slide. A wedge-shaped piece about 1 cm x 2 cm is excised frotn the filter with a scalpel and forceps and placed dust side up on the drop of mounting solution. A No. 1-1/2 coverslip. carefully cleaned with lens tissue, is placed over the filter wedge. Slight pressure on the * coverslip achieves contact between it and the mounting medium. TheI I BB 0021448 i w Mention of commercial products does not constitute endorsement by ---___ 1 the Public Health Service or U. S. Department of Health, Education, and Welfare. I,So^lNDUSTRIK,m>nCc... 3240 r wimple* may lx? examined as soon as the mount .is 2h rvnt. Tim ujAicat homogeneity of the resulting mount is nearly perfect, with only a slight background granularity under phase contrast, which disappears within one day. The sample should be counted within two days aftor mounting. Evaluation The filter samples mounted in the manner previously described are evaluated in terms of the concentration of asbestos fibers greater than 5ya O^ tr- u_> O --i. in length. A microscope equipped with phase contrast optics and a 4-mm high-dry** achromatic objective is suitable for this determination. 10X fr. C3 CL- eyepieces, one of which contains a Porxoa or other suitable reticle at the level of the field-limiting diaphragm, should be used. The left half of the i--tf 1 oo o ^a- Porton reticle field serves to define the counting area, of die field. Twenty fields located at random on the sample arc counted and total asbestos fibers longer than 5yu are recorded. Any particle having an aspect ratio O ud CJ> oo of thrve or greater is considered a fiber. The following formulae are used to determine the number of fibers/ml: (11 ~ Filter area fmm-1 ^ Field area (mm2) (2) Average net count x K . Air volume sampled (nil) " fiber*/ml BB 0021449 1 THIS DOCUMENT WAS NOT A RECORD OP PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC/ - 3341 29 For example, assume the fullowin;;: area of the filter used was 555 min-, counting area of one field, under the Foraon reticle was u.005 mm-; average net count per field of 2i fieUls was 10 fibers; and sample was collected at 2 liter?. j>_-r minute for 90 minutes. Then; 555 mm- _ "-= l<l,0Gii(H) . 0u5 mm- 10 filers x 171,000 9.5 fibcrs/mi 2,000 ml/::u:i x 90 min o <r> Anahtical Methods . The recomnienJoJ interim standard, as tutted earlier, is based on die number of asbestos fibers/ml > 5yu in lengtli to which workers are exposed, in many operations involving the use of asliescos, fibers other than or in addition to asbestos may be present in the sample collected. Thus, situations will arise where the airborne fibers must be identified. *" O LiJ p oo Furthermore, circumstances may require the identification or differen tiation of various types of asbestos fibers present is the sample. An experienced microscopist can easily distinguish asbestos fibers in the presence of rock wool, glass wool, and many organic i BB 0021450 | . fibers. However, it may be necessary at times to determine qualita- i-------------------- -- tively or quantitatively the types .of asbestos present. Several methods for this purpose are given In the Appendix and others, such as electron THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES. AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. 3S42 T r- 30 miuroprobe analysis, may lx: found in the* literature. It must be emphasized, however, that the analytical procedures described in the Appendix arc not recommended procedures because they have not been refereed by other agencies. Additional research is needed to develop analytical techniques which are capable of differentiating between the massive and fibrous forms. Alsr.. there is need for mure sensitive procedures to identify single fibers that are encountered in biological samples. CONCLUSION' The criteria, the interim standard, and the method for the collection -4-V , A* ` f-X' fr; t3 and evaluation of dust exposures to asbestos recommended in this report are based on the latest data available and on the opinions of experts in this field. On the basis of these data and opinions, an interim standard is a. O L* K -: j recommended to control workers' exposures to asbestos fibers at no more than 5 fibers pvr milliliter, M determined by the recommended method of counting only those fibers greater than 5 microns In length and based on ill c~> I* CD CZD ild. time-weighted average exposures for a 40-hour work week. The criteria do not include desirable data apt to be developed; e.g., all of the facts that should be known about asbestosis, the relationship between exposure to the various forms of asbestos and the'Increased 7~BB_00 2*14s"7 incidence of cancer associated with workers exposed to asbestos, the DOCUMENT WAS NOT A j^TR0NI h BE authenticated ^SpF^moUSTmES,NC. 3343 r= 31 relations* hip beta von asbestos diist levels, and minimal health effects. Nor is there a recommenced analytical technique to differentiate massive forms of asbestos front the fibrous forms although *cvrul techniques are described in the Api>ot:d;x of this report. Research in these and other areas will continue and the criteria H. I REFERENCES .32 1. Hendry, N.W. The Geology. Ocuurrenses, and Major Uses of Asbestos. Annals of the New York Academy of Sciences. Vol. 132, Art. 1. Fp. 1-760, -Biological Effects of Asbestos, 39G3. 2. Ayer, H.E. .etal. Study of Asbestos Processing Workers-Progrcss Report. Abstract and Table I to be published in AIHA Journal (Mar.-April 1070). 3. balr.er, J.L., andW.C. Cooper. The Work Environment of Insulating Workers. American industrial Hygiene Association Journal. Vol, 29, No. 3, pp. 222-227 (May-June), 196h. 4. Williams. II. L., E.J. Baier, andA.W. Thomas. Asbestos Exposures. (To be published in Arch. Envir. Health.) 5. Asbestos position paper. DIIEW, USPHS, BOSH, 1SG2. G. Wright. George D. Asbestos and Health in 19G9. Am. Rev. Resp. Dis., Vol. 100, pp. 467-179, (Oct.) 1969. # 7. _____. _* of the Departmental Committee ou Compensation for Industrial Diseases. C.d. 3495, 349G. KMSO, 1907. 3. Cooke, W. E, Pulmonary Asbestos is. British Medical Journal, Vol. 2, pp. 1024-1023, 1927. 9. McDonald, 5. Histology of Pulmonary Asbestosis. British Medical Journal, Vol. 2, pp. 102S-1026. 1927. 10. Hoffman, F.L. Mortality* from Respiratory Diseases In Dusty Trades (Inorganic Dust). Bulletin of U.S. Bureau of Labor Statistics, No. 231. pp. 17 G-1S0. 191S. 11. Pancoast. II.K.. T.G. Miller, and II.R.M. Landis. A Roentgen ologic Study of the EfTccts of Dust Inhalation upon the Lungs. Transactions. Association of American Physicians, Vol. 32, pp. 97-103, 1917. toes iUTm not co^froM Kbr EE authenticated 1DUSTR1ES,. INC. 3245 ... i--* -m N I - y 12. Jdills. H.G. Ihdmc-nary Asbestosis; Repor? cf a Case. Mi/mesota Medicine, Vol. 13. pp. 433-400, 1330. 13. Lynch, K, *- and W, A. Smith* AslfC3to$*s Hedies In SputuTn anil Lur.g. Journal of the American Medical Association, Vol. S5. pp. 659-onl, 1030. 14. Merewethcr, E.R.A. A Memorandum on Asbeslosis. Tubercle, Vol. 13, pp. G9-&1; 109-113;15Z-130, 1033-34. 13. Gloyr.e, S.U. The Morbid Anatomy and Histology of Asbostosis. Tubercle. Vol. 14, pp. 443-431; 403-407; 330-333, 1032-33. .10 Sulikoff, I.J., and C. E. Hammond. Asbestos Bodies In the New York City population in Two Periods of Time. International j? i Conference of Pneumoconiosis, Johannesburg, pp. 47-33, (April-May) 19G9. iIi t IT. Lane, F..E., el al. Hygiene Standard for Chrysctile Asbestos Dust. " ' r Annals of Occupational Hygiene, Vol. 11. No. 2, pp. 47-49, l&tis. -/ ' 1. Dreese.i. ,V.C.. et al. A Study of Asbestosis in the Asbestos Textile Industry, public Health Bulletin No. 241, (Aug.) 1933 13. Stokinger. II. E. Proposed changes in TLVs for Airborne * Contaminants, ACCHl Bulli.iu Board, Vol. 15, No. 3, (Jan.) 1970. .20 Holmes, S. Personal Communication. Asbestos Research Council, Rochdale, England. (Oct.), 19G9. .21 Ayer. H. E., and J.R. Lynch. Motes and Fibers in the Air of Asbestos Processing Plants and Hygienic Criteria for Airborne Asbestos. Proceedings of an International Symposium Organized by the British Occupational Hygiene Society, pp. 511-322, (Sept.-Oct.) 19G5. *' Lynch. J.R.. and It. E. Ayer. Measurement of Asbestos Exposure. Journal of Occupational-Medicine, Vol. 10, No. 1, pp. 21-24, lSfia. f bB 002145JM THIS DOCUMENT VIASNOT A gM** K^oA.'BEWil&TnCATffl by PPG INDUSTRIES,. INC. 3248 34 -.1. Lynch, J.It.. and ll.E. Ayer. Measurement of Dust Exposures in the Asbestos Textile Industry. American industrial Hygiene Association Journal, Vol. 27, pp. 431-137, J9Uj. 24. Keenan, It. . and J. It. Lynch. Techniques for the Detection. Identification, ami Analysis of Fibers. (Draft S^S/CO - Presentation at the American Industrial Hygiene Association Conference, .Denver, I'JkiD.) 23. Kcfo-anls, G.IL, andj. R. Lyneh. The Method Lied by the Public Health Service for Enumeration of Asbestos Dust on Membrane Filters. Annals of Occupation.*! llyr^ene, Po reunion Press. Vol. 11. pp. l-;, l'jns. ^ itt" f; ? L. 2ti. Lynch. J.R., H.E. Ayer, and L. Johnson. The Measurement of Exposure to Airoorua Mineral . Jbers. (^resented at the American Industrial Hygiene Association Conference. Denver, 19C9.) r 27. Ayer, H, F.. J. II. Lyneh, and J. II. Fanney. A Comparison of impinker and Meinlrano Filter Techniques for Evaluating Air Samples in Asbestos Plants. Annals of the New* York Academy of Sciences, VoL. 132, pp. 274-257, 19S5. .- ; ' L..` 1' c jToRw ndustries*. '.mc. 1 BB 00214S5 1 3217 APPENDIX: ANALYTICAL METHODS Modem analytical methods and instrumentation used in the identification and characterization of asbestos ratnemls include x-ray diffraction, atomic absorption spectrophotometry, emission spectroscopy, electron microscopy. electron mierc-probe, ihcnnoanalysis plus the necessary sample preparation * Internal Standard Technique for Chrysotile IT1 Sample preparation. The substances to be analyzed may be c t classified as settled (lust samples or as bulk samples of process materials. Settled dust samples analyzed for non-fibrous minerals by x-ray diffraction f are usually passed through a 325-mesh sieve in the preparatory procedure. Fibrous structures, such as asbestos, do not have the aerodynamic prop1erties associated witli approximately spherical lirbome particles; hence the preparation of asbestos-containing settled dusts consists only in a pre liminary screening of gross particles followed by grinding to less than 3.5 microns. This is accomplished by dry grinding in a mixer mill for ten minutes. \ BB 3253 3G ljulk sample* may be obtained from the materials used in an industrial projvsa. An alumina-ceramic \iai and mixer mill are used in preparing this type of sample for analysis. A representative portion of the bulk sample is pulverized in the mixer mill, as described for settled dusts. Procedure. The ground dust or bulk sample is first scanned O CO 1.U X : ,,.i with the diffractometer to establish a qualitative diffraction pattern. This preliminary analysis will verify the presence or absence of chrys- .3 X. 'X. ctile and will demonstrate* the presence of possible interfering o substances, which are discussed In a subsequent section. Chrysotile is confirmed as present by comparison of the sample's qualitative pat- # tern with that of the pure mineral. If the pattern is found, a rough estimation of the percentage of chrysotile is then made. \U r/'.-'-a :D 'O oo A mixture of the dried sample and the aquamarine, each weighed separately, is prepared: The combined weights should be approximately 1 g. The percentage of aquamarine in the mixture should be approximately the estimated percentage of chrysotile in the sample. ** * Toe mixture Is then wetted with isopropanol and ground in a mechani cally driven boron carbide mortar for 15 minutes. After this final gjj 00 21457 | t . grinding the'mixture is dried atTlOoc. and packed in the sample holder ' _ of the diffractometer for analysis. , ^ * remiss ".nor. iNDUSTt'.xb,'.'^. 3313 The. ratio of the arvi tarter the aquamarine 3.2S-A peak to the area under the chrysotile 3.G3-A itak is computed from the digital print-out record. BacLgr'-.ur.d corr=-.-_ :nj are applied to determine the net area cf a given peak- The avers, gv htreground count, calculated from the values provided over a fixed inter*.-1-trending on each side of the diffraction peak, is used to calculate the :.:ni) integrated background correction under the dill ruction peak. With the standard ear- ? al.en as a reference, the ratio of the weight of aquamarine to the- of chrysctile Is determined. The per- ` ceutage of ehryseiilo is corae-r-d from the ratio of aquamarine to chryswile, the weight of the iuit sample, and the weight of the added ** aquamarine as follows: (A x 2*M;/(S x R) * % Chrysotilc Where*. A SB R* weight ri aquamarine weigh: tg sample ratio of tqumnarlne to chrysolite (by weight) as reii from the calibration curve Standardization. A 3na*Iian aquamarine is used as the internal' standard. The clearest port!or of this mineral is selected for milling, and the ground material whica gasses through a 325-mesh sieve servesas / the source of internal standard. In our laboratory the sieved fraction of tho aquamarine was sized by eiwrron microscopy; 99$ of Its particles \ .* V* THIS CO-UME-.T WAS (COT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED PEG.INDUSTRIES. INC. t t. 4. *_J 3350 2a mua* urcd 3 O.u or U-stf. The ground ci rv le ua'ed in tin* preparation of ihe standard sample* was a Lao siuud by electron microscopy ; 90" of its fiber lengths measured 2.$u or less. The standard curve is obtained by application of the procedure to a series of mixtures of aquamarine ami ehrysoule. This series includes weight rat;.-'? of aquamarine to chrysotile of 0.5:1, 1:1, 2:1, 3:1, 4:1, and 3:1. Each mixture. in approximately 1-g samples, is mixed io the mill and finally ground m a mortar, as described under Procedure. The ratios of the intensities of the aquamarine 3.2s-A peal; to the chrysctilt# 3.A3-A peak {bwdi corrected fc-r background) are plotted against the weiglA " T0 * . 13 - * .-T* 3 * ~ ->is j ratios to obtain the standard curve. Each plotted ratio Is the average of " three to five replicate packings and scannings of each mixrure of sample ' and internal standard. / External Standard Technique for Chivsotlle. Amosite anti Crocidoiite ' . i ^ - .' These types of asbestos may be determined by an x-ray' diffraction and external technique. 3"- Proccdure. The substances to be analyzed are classified as settled dust, bulk samples of process materials, or airborne dust sam, ** pies. The preparation of asbestos-conmining settled dus*s consists of a -* preliminary screening of gross particles followed by grinding to fiber lengths of less than 3.5 microns. This is accomplished by dry-grinding in a mixer mill for ten minutes. THIS DOCUMENT was NOToA RECORDrOF jS E ^`mmE0 BY PPG INDUSTRIES, lNC` 3251 Jk JA; , - Bulk samples may be derived from the starting materials, intermediates or finished products encountered in industrial processes. A representative portion of a bulk sample is pulverized in the mixer mill as described for settled dusts. The technique of mounting representative portions of dust samples on a molecular membrane filter has been described by 1'alvitie and Brower."1 For this purpose, a Imown weight of the finely cutmr.inutcd sample is suspended in 250 ml of water i:- an MCA volumetric^ flask. Proper distribution of the material in water is insured by use of a wetting agent. Then the sample, which may include agglomerations, is dispersed with the aid of Oo a small ultrasonic bath. Au aliquot of the thoroughly agitated suspension, containing a known amount of the sample, is filtered using a molecular membrane filler. This method provides a . sample of known weight on the filter. This technique has proved to be applicable to dust samples containing asbestos fibers whose sizes are of the magnitude described in this paper. In-plant samples of airborne asbestos collected on membrane filters are analyzed without size reduction. From liber size meas- urements made at this facility,' the rango and the mean values have been determined to be.of the same .order of magnitude as those of the _____ --[ asbestos standards used to calibrate the method. .------------ THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT S FILES. AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. 3252 t* In-plant samples ox airborne '.stxj.stos fibers collected on membrane fillers may not be uniformly distributed on the filters. Asa uniform dis tribution ox the fibers is required for this procedure, an even distribution of the collected filers is obtained by removing the sample from its origi nal filter and redc-positing it on a second filter. This is accomplished by placing the original filter sample in a test twl.-c containing 3 few drops of a suits tile waning agent and sufficient water to cover the filter. The test tuS*.* is then immersed ir. an ultrasonic L-ati; for five minutes to remove the dust deposit from thv filter. The original filter is then removed from the tet iul*e and the siuj-c-nded dust is redepwsired ou a second'filter using -- tl.e technique described above. This is also a convenient point to aliquot heavy dust samples. U'. V-: The membrane filter with the aliquot of dust adhering to its surface ^ is mounted in the x-ray diffractometer. A qualitative scan, usually at r. l/min, is run on the sample to establish the presence or absence of asbestos minerals and of possible iaterforcncos. The area under the major diffraction peak of each asbestos *a L:j ' f-- . Oo mineral present in the dust sample is determined in order to calculate the weight of that particular form of asbestos. If the major diffraction peak is affected by that of another mineral present in the dust, them the --b" 22.11 IV second most intense peak of the asbestos mineral is used for a PPG /fiDUSTR^s^INC^Dn)1!- * *EC0RD *0F BY PPrES AND CAN,10r BE Mn?0^ FRom BY PPQ INDUSTRIES, INc/AUIHElVriCATE0 , * 3353 t. \ * 4 quantitative determination. For determining thi.* .1 rc-.i of a pi-ak, the' -il dliuuctometer i o-orated at a low scanning speed (o. ^/tnin) and a slit combination of l6 lcain ilit, medium Sutler slit, and 0.2 detector slit. The area under the peak is computed from the digital printout record, Background corrections are applied to determine the r.et area of a given pt-ak, The average background count calculat-.u from a fined interval extending on each side of the diffraction peak is us-, d to calculate the total integrated background-correct ion under the diffraction peak. The net urea of a given peak, computed from th printout data. is referred to a standard curve relating peak area, expressed in counts. to the weight of the appropriate asbestos mineral, expressed in milli- * grams. The latter quantity is the amount of thu mineral represented in the aliquot portion of the analyzed sample. Standardization, Pure asbestos minerals are used as the external standard*. Because some composition differences do occur In asbestos * minerals of a gtveir class, the standards should be obtained from the 5,-. same or a similar source as that of the asbestos present in the dust samples. The minerals used In establishing the standard curves are treated as described in the Procedure.- In our laboratory these prepared * minerals had fiber lengths less than 3.5yu for 99^ of the amosite and 462 1 THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. 7 3SS4 4. 42 crocidolite fibers and less than 2.5^n for 9?';, of the chrysoiile fibers, as determined by an wlaetron microscopic siziug procedure. A 50-tng quantity of each of th pulverized asbvsios minerals Is placed in an indivtcizl 2'><>~ml, MCA volumetric flask. The suspensions an* prepared as <!,,-*.nb-:*U for the duet samples. Aliquots containing one to ten m; of :t gi*. on asi>estns standard are removed and trai^ferred to ii.zivuiua1. mvs.ihrur..' filters. A separate Series of these standards ii prepuivd for each mineral. The major (cr primary) diffraction peak is counted to determine the area. The net area, alter correcting for background, is reported in o t;;r-' *p counts. The relationship of the weight on the filter to the area under a given diffraction i-.-ak is a linear function. The planing of counts ?cd mg of mineral provides the standard curve. These standardization data arc obtained from replicate analyses of the filler-mounted standards. A set of three filters is prepared for each concentration level of each mineral. The total number of analyses performed for the standardization of the c 1-- o * * ,-~J> U-i , W-- j -J-- oO method: involved two to three determinations per filter. These absolute deviations, represented as milligrams (mg) of a specific mineral, were uniform over most of the usable range of the method. The relative standard deviations were as follows: 1. a to 5% for 1 to 10 mg of chrysotilc, 2 to 5 for 1 to 3 mg of crocidolito, and 2 to 5.5% for 1 to 8 mg of amositc. THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. pBB 0021463^1 3255 ' 43 On the basis of these data, the working ranges of the quantitative method arv 1 to 10 ir.g of chrvsctile and i to b mg of orocidelUu or atuositc if the deviations are to !:*; held wtihiu the indicated limits. Infrared S;cctrOgc.'pv Infrared (lit) spectroscopy involves mixing a dost sample with potassium bromide to mate a pellet which is inserted into the LR spsc- U\*meti-r to obtain a.spectrum of the sample components. From this spectrum one can identity the major dust components. Method (Qualitative), A 0.3-mg dust sample (ground so that greater than uOT. of the particles are less tlian 5^u in diameter) is mulled for 3 minutes with 300 mg IK quality potassium bromida until thoroughly mixed. This mixture is pressed in a 13-mm die for five minutes at 23 tons pressure after an initial five minutes of evaciation. A clear pallet about 0.79 to 0.83 ram will result. This pellet is then placed in the Instrument and scanned from 9 to 30 microns. From the resulting spectrum one can identify the asbestos constituents.5 tii ^ oo Method .(Quantitative). Although this method has not been used for the quantitative determination of asbestos components, e.vp-rimenta have shown tint 10 micrograms of quartz- can be delected to :=-3x scale expansion. In a 10 mg sample this is 0.1% sensitivity. Only under certain conditions could asbestos minerals be quantified. isjoSSi-i .c nrrUMENT WAS NOT A RECORD OF G INDUSTOBS.WC. DID NOT COME FROM s FILES. AND CANNOT BE AUTHENTICATED ' PPG INDUSTRIES, INC. ; 3G5S m The III sj.cct ropitwtomdnc method nu:>i W ilbCcI with great cure fur \ th'.- idcutifu:.tio:i yf specific forms of occurring in mixtures. The }. ctm of various mineral components may overlap and make indivitLal identification very duiicult or impossible. This method is nut preferred f.-.r ipiasitituiive analysis. raiZcrcntml Thermal Analysisof Chi-ysorilo The implica:i'>ti of chrysolite as a causative agent in certain types of pr.etuiiuvoaiG-is hue- resulted in the appearance of numerous methods (i analysis (botli quruaitutivc and qualitative) for chrysotile. One of theso methods is differentia! thermal analysis (DTA). The relatively simple DTA experiment measures temperature cUtferencc 1x,*t\vc*en a sample and an inert reference material as both are heated or cooled at a uniform rate. By indicating the gain or loss of heat from a system, DTA signifies when a component undergoes a physical change such as fusion, sublimation, or vaporization. Since these phys ical changes generally occur at different temperatures, a unique thermogram can be obtained for most thermally active materials. While the principle behind DTA has been known for a long timo., s * it has only been recently tliat acceptable thermal analysis equipment lias become commercially available. | BB 0021465 | THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. 3G57 , i 7 ; 9 -d*.' 45 Conac.-jucr.tly, the DTA technique will undoubtedly improve with time. A large nur.:U*r of chrysolite samples from various locations throughout the world have already bven characierized by DTA. * technique has also been used to detect the presence of ciirysotllv in filled resins. *0 I)TA is a re latively simple technique especially applicable to samples i-oeuimng a sir.4k* rui:,*. rul. However, d;:;;cullies arise vheu multi- c.>.',ip..:.e'.t are i.i be analyzed, since the unique thermograms of individual con.ponvr.ui may not be differentiated. Atvinic Al* spoc;r->p`notvri.t-try . An ir..;.rvc*. vstinmiur. of chrysolite may ii* made by utilizing the ih tvriiiiiuiUon -/ iiia-p:esiuni iu chrysoti le-bcarir.g samples by means of O TJ v2 f. \3 t- atomic absorption spectrophotometry. Chrysolite asbestos, a hydrated magnesium silicate.' is readily C^r;' ? ' broken down by mineral acids. On acid treatment the combined magnesium 2 :jj is dissolved cut and can be determined by atomic absorption. T" ^ (r|34 p-- II the general formula (3MgO 2SiOs 215,0) Is used for chrysolite. the theoretical magnesium content is about 25^. With this information OO ; and ike magnesium content of a given sample, it is possible to calculate the approximate amount of chrysotile in the sample. The assumption wuuld have to be made that the sample contained no other magnesium- ____ , "X"n 21 \ ^ THIS DOCUMENT WAS NOT A RECoR? PPG INDUSTRIES, INC. DID NOT MME FRO" IT'S FILES AND CANNOT BE AU ftStNTlCAl ED pv PPG INDUSTRIES, INC. 32S3 4G bearing curr,|HMiils other than chrysotilc. Most of the samples analyzed to dale love U-en airborne particulates collected on membrane filters. Sample Treatment. To the membrane filter sample in an acitl-ch-rviivd Phillips beaker is added 10 ml of 6i; HC1. The sample is then heated wn a hotplate (KJ0C.) for*ziTt\i 30 minutes to torally break duutin* ch-ysutile. The resultin'; solutio: J :s transferred to suitable velumetne gLisswurw ami adjusted to a lr/>*.vn volume. Aietlysts. The nm^nesiunt conit^: of the sample is determined by atomic ansorpibM(specirophotoiuetry. Both single ole*met* and multi-clement hollow cathode devices have tK*en used to produce the Mjj lliGSA resouance line which is used for the analysis. The percent ahscrptiou at this line is used to calculate the magnesium content of the samples. Aqueous standards are prepared from a stock solution made from a pure magnesium compound and a standardization curve is run. The range of the method as used Is 0 to 2^ig of Mg per ml of solution. Each standard is 0.3N in KCi. The absorption for unknown samples is referred to the standard curve. The magnesium* content in^ug per ml is determined, and a final value for total magnesium in the* samples is calculated by using the total volume flguro for each sample. OO document was NOT A RKOSD OF INDUSTRIES, INC. DIO 0^ ^ FILES. AND CANNOT BE AUi r.ENTlCATED PPG INDUSTRIES, INC. 3SS0 This method hits been used primarily for small sample* (0. 2f* ug) t 7* ' obtained by using personal samplers, i.arge samples require such \ dilution that considerable error may be introduced by dilution factors alone. It must be emphasized that this method will only determine the i inugnC'Sium content of the sample. It does not determine the parent compound that contains ti.e magnesium, whether it be magnesium car bonate or one of the types of magnesium silicate. In the analysis of an unlaiown sample, the duhic-us assumption would have to be made that chrysolite was the only magnesium compound present. Attest, this method provides only, an indirect estimation of ehrysotile. ms document was not-a record of. 3G INDUSTRIES, INC. DID NOT COME FROM -S FILES AND CANNOT BE AUTHENTlCAlED V PPG INDUSTRIES, INC. | BB 0021469 | 32S1 i' r' % Rolerentes 4S ,. 1. Keenan, B.C.. and II.E. Kuj*.*l. Modem Analytical Techniques for Evaluating Mixed Environmental Exposures to Fibrous and Particulate Dusts in the Asbestos Industry.', Presented at the 9th Conference on Methods in Air Pollution and Industrial Hygiene Studies, Pasadena, California, lhCS, 2. Crublw, J.V., andM.J. Knott. Application of X-ray Diffraction to the Determination of Chrysotik in Bull: or Settled Dust Samples. American Industrial Hygiene Association Journal, Vol. 27, p. 3s3, 1`jiiii. ' j 3. Cruble, .l.V. Quantitative Determination of Chrysutile. Amosite, and CrocU'olilu by X-ray Diffraction. American Industrial Hygiene -- ; ; \ Association Journal, Vol- 27,.p. 203, 1966. s 4. Tnlvitie, N.A., and T.. W. Brower. X-ray Diffraction Analysis of Industrial Dost. American Industrial Hygiene Association Journal, Vol. 23. p. 214, 19G2. \ * 'Tr t,: 1. 5. Taylor, D.C., C.M. Nenadic, andJ.V. Crable. Infrared Spectra for Mineral Identification. American Industrial Hygiene Association Journal, Vol. 31, p. 100, 1970. * c '. f 6. Qalser, M.A., M.K, All,and A. Khan.Mineralogy of Some ^ Asbestos from Northwest Pakistan. Pakistan Journal of Scientific ( Industry Research, Vol. 10, pp.116-120, 1967. t\ \ . U^i ' ' r~- JTM* 7. Martinet, E. ,Tho Effort of Particle Size on the Thermal Properties CD CD of Serpentine Minerals. American Mineralogy, Vol. 46, p. 901, 1966. 8. Faust, G.T. , and J.J. Fahey. The Serpentine Croup Minerals. U.S. Geological Survey-Professional Papers, 3S4-A. 92 p., 19G2. ___________________ f . G_ 002?470~7 r * I )OCUMEMT WAS NOT A RECORD . DUSTRlES, INC. DID NOT CO.dE FRO^ LESAND CANNOT BE AUTHENTICATED fi INDUSTRIES, INC. 3CS2 Hay 1, 1970 R***3aded Criterla *r.d Interim Standard for rreveotlon of As bento*la Director, BC22 1. Enclosed for your review, consideration, aad disposition is a docuac-nt oa the above subject, which was approved by all but one locsber of the Review Ccrrnictee es Asbestos. 2, This doc^snt mis prepared according ta the preccdureo as 05clined to ycu previously sod lnclu^e-i the failcvioj steps: a. A rough draft was prepared by the "workleg ccsslttce," ccapoeed of several Bureau personnel*. b. The rcnh draft was rev laved by tho '`internal review cenaittc*" in July 1S>s9. Extensive revisions wore cade and lc was re-revisued duri.ig August. c. Copies of cbe first draft of the proposed criteria and reccww;Rdd laterla etaedard ware sent to the Review Ccualctve ou Asbestos, Septecber 5, 1369. t.--. -1 !" d. The JUvleu Coccltte* twc all day, September Id, 1969, at 1014 Lraadvjy asd reviewed this draft. (Savon mrrScre of < tha Review CAoittee -- Hr. Lsxsdea aad Sr. Hocre were not presvot -- aad 14 BASH peraoaoei attended.) Xasy changes wore suggest**! la the vrtca-up. additional data were promised, but there wes general agreement oa a Halt of 12 tlberx/sl as the standard. Thro* aaabars of the Ccnsictew agreed to supply additional saterial. e. Additional a* t trial was received la Jacaary 1970, the docnosat was re typed,, reviewed internally, aad seat to 'waters of cha Review Coatitten oa February S. v.l * " .* O Jrwniv Oo f. The Ravlw Ccanittae sat at 1014 Broadway oa March 6 to review the second-draft. All but one ocsber agreed eo a standard of 5 flber*/sL based on -a' tLaa-weighCed exposure with a celling oi 10 ilbers/ml sot to exceed 15 clsutes la any hour for 5 such periods per dry. taler, lee aad -ioore were not present. A few changes la tbe aecend draft were suggested. ' .. *i-&B*"o02l471 ,1----------" THIS DOCGmENT V/AS NOT A RECORD OF - PPG INDUSTRIES. INC.-DID -NOT COME.FROM. IT'S FILES AMD CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. . ' . .. ; ?* 2 - Director, ECSS . 2aa*d o letters *ed/or telephone call* up to April 17 to MtcU *&7 further differences, a third draft \a ?r* pared.' All Ui ess aenoer of the cosmic tee roeffirmsd cbslr earlier esteem*at on tha criteria and rocorsoiulod lateria ctoadard of S flbrp/*l ^ 5 /* la lrr^th, based on a else evicted averee3 t=?osur* and a eelllcQ cot to exceed 10 ilbers/al for 15-aicute period during *07 cno bcur nee to exceed 5 toch periods per day. 3. It U rcccnnctdod that the criteria and interia standard (third reviiid draie) be forwarded through pcorer chacaela tor edeptica. Aadrav D. Eoscy, Director Division of Criteria and Standards Development bureau of Occupational Safety ami lisalth Enclosure r cc; Review Ccaaictee panbaxe AWICSZYjva utfw < it this ooaiM^Jewrefuom fr S FILES WD CANNOT BE AU rHENTICATCB BY. PP.G INDUSTRIES, INC. . nipw +. 5 j oo 2: ^ I'eToo^SI--- \ --------------- 32S4 >gr 1' t