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FILE NAME State of the Art Literature SAL DATE 1967 DOC SAL079 DOCUMENT DESCRIPTION Journal Article - The Work Environment of Insulating Workers The Work Environment of Insulating Workers J. LEROY BALZER and W. CLARK COOPER MED ainments ainments Health Sciences School School Caldiventa Pure 5472 Strach Strach bo ergs, # With the cooperation of the asbestos workers union and insulating contractors a study is being made of the environmental exposures and the health of insulating workers in the western United States Surveys have been made in a number of work situations including small commercial building major industrial construction and marine operations Major emphasis has been on exposures to containing materials fiber glass cork plastics and adhesives Freuds in product usage are presented as well as illustrative dust counts based on membrane filter and impinger samples for various components of the insulator's job ... prefabrication application finishing mixing and tearing out of old insulation Introduction WORKERS WORKERS IN THE insulating made make up an occupational group known to have exposures to asbestos that are varied and difficult to control In recent years in- vestigators have shown that the relationship between asbestos minerals and human disease extends beyond a disabling pneumoconiosis produced in some workers Evidence has ac- cumulated that asbestos workers have a high- er incidener than average of of malignancies of the lungs pleura and peritoneum Asbestosis in insulating workers has been reported in England by Ellman in 1934 and by Leathart and Sanderson in 1963 in the United States by Fleischer et al in 1946 Pendergrass in 1958. Marr in 1958 and by Selikoff et al in 1964 in Sweden by Ahlmark et al in 1960 and in Finland by Ahlman in 1966. Selikoff reported lung cancer deaths in insulating workers in New YorkNew Jersey to be over six times expected This investigation was supported by Research Grant OK 09204 froin the Public Health Servier S. Department of Health Education and Welfare and received preuminary support from General Research Support Grant 1.501.FR. 05441 Public Health Service 5. Department of Heal~-b Education and Wellare Ehis eegrert: 15.15 ...ycteAtoriatina Atoriatina May 5 1967 presented the American Industrial Cutleven In Chicago Honetes 16 Dunn and Weir in 1965 reported a higher than expected incidence of lung cancer in California and Keane and Zavon in 1966 in their descriptive report of the insulating trade in Cincinnati also described an excess of lung cancer Because asbestos may be a widespread en- vironmental contaminant and the established threshold it yas need examination there is need for a thorough appraisal of the work environment of the insulating worker We now in the process of doing a study et San Francisco area insulating workerisn order to determine the incidence of pneumoconiosi and malignancies and make observations observations and measurements on the work environment This report summarizes our preliminary environmental findings on the materials used inethods of application and dust and fiber cor cenuations Background Information on Union Membership This study was made possible by the whol hearted cooperation of the International Au sociation of Heat and Frost Insulators and Asbestos Workers both from their national headquarters and from the officers of their various locals , and by insulating contractors individually and through the Western Ase 222 Anunean Indart sanion of Insulat approximately approximately 1 Westert States Westert States i workers within Hancise Local Local This This Califor local at pre- members " Trade more than than 20 years T Hare fund has spor sary chest flims 1 307 of those migi view of these films the members he ges strongis suppo tosis with an equi restive changes Most of the loca one of the 20 or s the area and trave specific firm The irom contractor to men have worked tractors at soine th 25 years Neverthe ene ngid Men arising out of apprentice tes who qualify prentice school pre trade for their wor Insulating worko major jobs in thei work at any joh ass patcher Some prei arction or on the types of work in wh be classi^-ed as : which involves duct systems in the offi shopping centers et building which in B arbines boilers p processing equipmer tories etc and 3 tepair which invo milers pipes and . both naval and pa does not have jurisdi ards in the Bay Are wal unions but ma . . a . Hee Prregeteng Pte Seeth fese so fruanal 223 KKllaattiioonn cee at Insulating Insulating Insulating Nimately Nimately 1,80 1,800 Western States but ers within the Local Ne Tins Northern Caluerna local at present members 0 ye Contractors Contractors Contractors Contractors Contractors TThhereere are insulating workers in the is report is imuted to sdiction of the San op and which encoencommpasspes aencompas sencsompeassses Northern Northern Nevada has approximately approximately 500 | trade more than sears 4277 than 20 years The union's wealth fare fund has sponsored a program for more and wel of volun- tary chest films for the past 10 years 1 of those eligible have participated and Rr view of these films has shown that about 25 of the members have roentgenographic chan- ges strongly supporting a diagnosis of asbes tosis with an equal percentage having sug- gestive changes Most of the local union members work one of the 20 or so the area and travel insulating from job contractors in to job with a pecific firm There is considerable shifting from contractor to contractor so that many zen have worked for all of the major con- tractors at some time during the past 20 years Nevertheless the trade is a stable ne arising out of a high wage rate and a egid apprentice testing and training program Men who qualify and pass through the ap- prentice school program tend to stay in the grade for their working life Insulating workers learn to do all naior iobs in their trade and usually work at any job assigned by their union the will dis- catcher Some prefer to work in heavy con- building mirtion or on the waterfront The major apes of work in which men are engaged can x classifed as 1 commercial which involves duct systems in the insulation of pipe and office buildings apartments shopping centers etc 2 heavy industrial building aurbines which involves the boilers pipes duct insulation of systems and processing equipment in power plants fac tries etc. and 3 marine construction and repair which involves insulating turbines boilers pipes and duct systems in ships in both naval and private vessels Local 16 does not have jurisdiction in U. S. Navy shiptards the Bay Area which have their own ical unions but many of the members have in the the sands past been employed employed in ; the the naval ship- The following is a breakdown of employ- ment by types of construction of the 401 ar tive members working as of March 31 1967 Bk of the workers were employed in com- morial building 235 of the workers workers were employed 6 of the in beavy industial building and workers were emuloved in marine construction and repair The majority are emanioved in the building trades is an increased demand for shin and repair there must be a shuit When there construction of the union popilation For example during World War II more than 1.800 insulating workers were empioyed in Bay Area shipyards even though the local's membership was only 500 mem- hers This was due to travelers rom other Incais and a large number of workers from other trades given temporary permits to do insulating work during this peak period However the general picture is that there are jew travelers and the Local 16 membership handles most of the ions in this area Rota- tion between employers tends to keep the local inember working in this area for the duration of his working lifetime Insulating Materials Used Our analysis of the insulating worker's environment indicates that they are predomi nantly working with calcium silicate and magnesium carbonate insulating material con- raining asbestos fibers fibrous glass mate- rials plastics foam glass cork and adhesives 1. Materials Containing Asbestos- 1000 == Amosite blankets 9577 Amosite filler 10-15 Mixed amosite and chrysotile -85 magnesia 10-15 Amosite calcium sili cates 10-15 10-15 Mixed amosite and chrysotile -85 calcium silicates Mixed amosite and chrysotile 857 calcined diatomaceous si- lica 1000 500 Chrysotile asbestos shorts for finishing mud Asbestos shorts and 50 cement for finishing mid . N . o . 224 224 hore 1969 2. Materials Containing Fintous Glasse Glasse Monchinek- remipressed Monchinek- remipressed glass and re RAK RAK RAK Prefabricatese proe lore ces " Mineral wool High tenuernbue insulatio insulatio Finishing materiais umads Mineral wool and cement 3. Plastics prefabricated product powdered powdered Polyurethanes in places prefab ricated products 4 Cork 100 cork blocks * Glass Flakes Foam glass TABLE 1 Estimated Percentage of Volume and Application Time by Types of Insulation Material in Use the San Francisco Bay Area Beef Beef jassalatine Material Volume % of total .: Aspektow Fibrous Cla Cather cera tabber foam glass pore getes poivurethanese PMI ti ti ms Application of tune 100 55 +1 5 TABLE H Examated Pricentage of Current Use of fibrous Glass and Asbestos Containing Materais by Major Types of Constructive Types of Construction Construction Fibrous Insulation Materian Used Inta Fibrous Glass Asbestos Commercial building Heas industrial buigine buigine Marine construction and repair 1005 100 2141 tire 30 20 3017 50 , , Tante III Characteristic Properties of Chrysotile and Amosite Properties Properties Properties Crystal structure structure Coine Approximate diameter of smaliest hiwers nake Specific gravity Index of action Chrysoble Sheet silicate Wlute CS eo ey 2.55 1.567-1619 1.567-1619 Autosite Chain silicate tires 091-01 091-01 345 1.6-1.708 1.6-1.708 1.6-1.708 1.6-1.708 6. Adhesives Epoxy and solvent asphalt hase and sois Wheat paste Silicones Magnesia Portland Cement Table is an estimate of the products used by voimme and the approximate times spent in applying them This information was ob- tained from the contractors men in the trade and from personal observation during the year This taiie shows that fibrous asbestos and glass materials account for 90 of the materials applied Tahie II presents the percentage of fibrous insulation materials used by the contractors in our area by major types of work area These fibrous materials were of paramount interest to us in reconstructing the work environment of insulating workers Physical and Chemical Properties of Fibrous Materiais Asbestos Ashestos is a commercial term applied to group of fibrous silicates They include chrv sotile and the amphibole minerals lite amosite anthophyllite anthophyllite tremolite and actinolite Chrysotile fhydrous magnesium sili cates is the most important commercial as bestos mineral presently accounting for about 90 of the world's asbestos production It occurs only in serpentine hydrous magne- sium silicate minerals rock formations Am- phibole type asbestos is found in five commercially useful forms crocidolite amosite anthophyllite tremolite and actinolite In the United States insulation industry chrysotile Canadian and amosite South African are most often used in manufacturing insulation materials Table III A unique physical characteristic of asbestos is its ability to longitudinally subdivide into fibriis of molecular diameter The fibrils are too small to be counted with ordinary light microscopic techniques making it difficult to assess the true ^...berexposure From the literature and from manufactur ers and their representatives we ascertained American 14 the approximate a tos fibers which ar ent asbestos insti tured by seven m^ materials in the anation is summari firmed the stated seven of the mate analysis using a No with a copper tal tube The manufactu materials use vary asbestos fibers in th brand their produc er manufacturer ( specific types of ash their thermal prop the type of asbestos practices on the p contractors nake it a working populatio exposure to one typ been our practice i to record all the i used in order to de bility by the insula any one type of ins more free fibers Fibrous Glass Fibrous glass cons dioxide oxides of al sium boron and ot the fibers of most co ncts have a tuean ,, greater Although t consider fibrous glas obtaining environn alyze it later . In our laborator termined the diame samples of fibrous used in our area have the largest dias - the building and ,, microns pipe cover the special high ten 2 microns It is evident from difficult to find gia environment that a American Industrial Hygiene Hygiene Hygiene Association Association fournal 225 the approximate amounts and types of ashes 154 fhers which are used locally in 14 differ : mt asbestos insulating products manufac tured by seven major producers of insulating materials in the United States This infor ation is summarized in Table IV We con With the insulation materials increased use of high temperature and special fibrous glass insulation we are likely to see more and more fibrous grass insulation materials with 3 mean diameter of respirable size inned the stated types of asbestos fibers in seven of the materials by ray diffraction Environmental Data | analysis using a ith a copper Tibe Norelco ray unit equipped target and ray diffraction The manufacturers of asbestos insulating materials use varying amounts and types of asbestos fibers in their products and may rebrand their product for distribution by anoth- manufacturer Contractors will also order specific types of asbestos insulation because of their thermal properties and not because of the type of asbestos fibers they contain These As was described in the previous section the insulating worker works with and is ex- posed to a myriad of materials and conditions Many times the materials he is exposed to result from the activities of other trades in the area Obtaining a true weighted exposure under these conditions is impossible It would require hours of observation and sampling of each worker in order to even attempt to estimate the integrated dose Exposures in most other industries are fairly practices on the part of manufacturers and contractors make it impossible to reconstruct working population that has had a pure xposure to one type of asbestos fiber It has been practice in environmental sampling record all the insulating materials being sed in order to determine product accepta- acceptaSite by the insulators and to determine if if constant by comparison in that workers continue at the same job in generally the same area However the insulating worker is always in changing environment the work Incations his position materials humidity temperature ventilation and any number of other things are in a continual state of flux i one type of insulation material produces Sore free fiers Ehrous Glass Fibrous glass consists of a mixture of silicon Loxide oxities of aluminum calcium magnesam boron and other additives In general fibers of most commercial insulating prod- have a mean diamete of 4 microns ca greater Although this paper will not directly consider fibrous glass exposures we have been Staining environmental data and will analyze it later In our laboratory we have optically deermined the diameter in microns of various amples of fibrous glass insulating materials ased in our area The acoustical materials In an attempt to reduce this to some order we have formed by the classified all the jobs per- insulation worker into six major categories ( Prefabrication materiais are precut and shaped using hand or power saws either on the job or at the contractor's shop 10 of his time 2 Application materials are fitted hammered un carved and attached to the surface by wiring or gluing 40 of his time 43 Finishing materials are coated with asbestos containing cements resins asbestos or cotton cloth or petroleum based sealers 30 of his time` 4 Tearing out removal of old or 20- usable materials in the process of insulating or reinsulating 100 of his time 151 Mix- Save the largest diameter 11 to 14 microns Taber IN we fe building and duct insulation 4 to 7 microns pipe covering + to 6 microns and Percentage and Type of Asbestos in Insulating Products in Current Use Se special high temperature material ? microns 1 to spe of Ashestos Percent by Weight Number of Products is evident from this data that it is not Anvisite Amnusite 10-15 I 95 199 i Pe difficult to find glass fibers in the worker's Amosite Chessotrie Chessotrie 14-15 iy Chrysotile 10-15 a environment that are of a respirable size Chrysotile 85-100 3 a 226 226 May June 1968 Dust & Sa: TABLE A rations oe Based on Tipmen Classificane Classificane Danne VE Einer Concentration Concentration Filter Sampurs by Based on Membrane Job Classification Number of Jun Clas.heation Class.heation Class.heation Jun . unpies Prejane rat i Application 7 Finshire Trating Mixine n General 4 i f Mean Mooin woe 33 BS ff ue we $8 ons id a a4 ld ta Raner fet Cheation Cheation 1R.th a RR? VIR! 2hbr DR mle Pitabrication Application } Dung Tearing out Mixing General Number Number ( Satipoes Satipoes - : i t) we <n oe Mestar a5 $ ae i _ Raner 1-243 616 0.1-244 0.1-244 led a Cee hs tee ing mineral wool asbestos fibrous glass and cements or glues are mixed separately or in combination in buckets or troughs 377 of his time 6 General cleaning up of old insulation transporting of materials 50 of his time The percentage figures indicating the amounts of time spent at each of the job classifications are of course variable and are only intended as rough guidelines For the purpose of this paper we will limit our discussion to the environmental data obtained during insulating operations when only asbestos containing materials were were used To compare our sampling data with the present threshold limit value TLV of 5 million particies per cubic foot we have taken a number of midget impinger samples along with our other methods of sampling The results of the impinger samples are summarized in Table and are either breath ing zone or general air samples of a particnia insulation operation All the samples were counted in accordance with the standard procedures prescribed by the American Conference of Govemmental Industrial Hygien- and include both grains and fibers It will be observed from Table V that we have three distinet prefabrication tearing out and where the present TLY is exceeded Because of our interest in the role that fibers play in the pathogenesis of asbestosis we piaced the major emphasis of our en vironmental sampling on obtaining fiber concentrations under various working conditions The personal and general samples were co^ iccted on Millipore Type AA Filters mounted in field monitor cases Most of the samples were breathing zone samples worn by the workers for periods ranging from 30 minutes to 3 hours Since it was easy to overload the filter with fibers during heavy dust and negate the countability of the it was necessary to replace the field periods sample monitor cases several times during the period The fibers were counted sampling by clear- ing a shaped segment of the filter using a modified technique of the United States Public Health Services and sized by the length and diameter at 430x inagni- ^"cation using phase contrast illumination will only refer to the total fiber this paper A fiber is defined as counts having an aspect ratio of 3 length to diameter If Tabell's criteria for respirable fibers diameter smaller than 3.5 microns was used 986 - 2 of the fibers we have counted would fall into this category The fiber counts per cubic centimeter are given in Table VI job classification Discussion Our environmental observation in the insulation trade confirmed our initial impres impres sion that the varied job assignments con struction methods and materials used in current work practices make it extremel difficult to reconstruct a weighted aver- age exposure for the major hazardous dusu and chemicals Reconstruction of past ex- posures is impossible Although materials in use have changed over the past 20 or 30 years with an increas ing use of fibrous glass and a decreasing use of cork the construction industry continue to demand containing insulation ma- terials The insulation worker's exposure to asbestos fibers is not disappearing It is also evident that contrary to most other United American Industrial . States industries where cur chrysonie asbestoasbesstos the use of aunsite asi turing of insulation posures are TOP sulating trade most The breathing the dustiest operations high as the incident may have led as tm. areas exceeded the value TLV recomm however these samples periods of time Altho sample the dustiest e weighted averages for ing asbestos would pro TLV in most situations conforms to findings by Marr and by Leathart to recently reported fine last year reported studi yards earlier appraised . The present TLV for mended by Dreessen t epidemiologic studies in chrysotile asbestos It extrapolation to all fo under all circumstance proven occurrence of a vilating workers xpos described in this paper previously cited suggests asbestos is too high 0 ever not yet complete final conclusion We In the article Diagnosis of Occ Journal 135-14 on page 139. In for item 3. Misc mediately follow concentration I TWAC American Industrial HygienHygeiene Association Journal 227 Hainer I Kaa mat wha e sreoearpes Cem mDie ta States industries where asbestos exposures ac- cut chrysonje astestos has not yet supplanted the use of a . asbestos the manufac- turing of insulation insulation materiais Amosite ex- posures ate most significant in the in- sulating trade The breathing dust levels found in dustiest the operations observed were not as high as the incidence of pneumoconiosis possibility that other components of the in- sulating materials may be synergistic The incidener of pneumoconiosis in these workets the need for better environmental con trol measures and medical surveillance surveillance will the subjects of more detailed later reports References nutes i the periods umpie uniter may have led as to expect Some sample areas value exceeded the present TLV TLV recomended TLV recommended threshold limit by ACGIH by the ACGIH however however these samples were not for extended periods periods samnie samnie Although attempted of time dustiest dustiest we to the dustiest operations operations the time- time- time- weighted averages for dust samples contain asbestos Pacume 1. ELLMAN . Part $91 Ashestans Brit J Kad~- 2 281-1954 281-1954 Panonary 2. Liatkaar G. .. and Sa nderson Some Observa- tions on Asbestosis in Occup Hic 63 1953 3 Fleischer .. F. Viles RJ RJ GLD and ^ Duiskra A Health Surves of Pipe Govering Operations in Constructing Naval Vesten 28. 1946 1 Indast Hye 2 Thx + Pendergrass E. .: Silicous and a Few of the Other Pneumoconinies Amer J. Racutgene Radium Therapy Nuch Med 80 171958 upling probably Overhaul T Naval Vessel ing asbestos would exceed the not Mann W. 5. Asbestos Exposure During Amer Tudust Exposure 23. 264 Vessel riear- TLV in most situations even on ships This 6. Selkoff J. J. CHErg and I. C HAMMOND Ashes filter conforms findings by Fleischer alo by tos Exposure and Nesprasia MA MA 38 22 1964 Lini- Marr hy Leathart and Sanderson and - aHntd MaOtrhker APXnEeLumoTc.amBiantueesr 1a7nd SuA.rdeNnystro^pm 3S5il3i-c1os5i7s wer Scandinavian I sized findings findings Fer is recently reported findings by Ferris who 31Mid University Bevsics Stockholm Surden magni ards oe sation e Lounis Laving by Severas Public Health 1367,1965 Foilowed Prospectively ee cter Shei e oe a. 10 rie last year year reported reported stuciies stuciies earlier appraised by in in the same same Fleischer ship- ship- The present TLV for asbestos was recout- mended in Dreessen it alth in 1938. after after epidemiologic chrysotile chrysotile asbestos studies chrysotile asbestos It in textile mills using . intended intended was not intended for extrapolation to all formsforms of asbestos use under proven proven all circumstances of exposure The of oc ur ence occurrence of pneumoconiosis in pneumoconiosis in in- AJTEMESS .: chestras Finland Preecedings of on Decupational Health Health Sept 1946 Among fosulating Workers in the 14th International International Congres pp PT Vienna Austria 55+ Q Dess E. and M. Weir Cancer Experience of Severas Oc upational Ocupational Greurs Foilowed Foilowed Prospectively ] 10. Kease W. and M ZWON Occupational Haz ards of Pipe Insulators AMA Arch Arch Entiron Health 13- 171 1966 11. Conver C. Material [an6, and R. Tahershaac Unpublished 12. Eowirus / and R. LYNGH The Method Used the S. Public Health Service Su Koumeration of 2UNen vilating workers described described in this exposed intermittently intermittently intermit ently as paper and by the authors Asbestos Dust on Membique Filters Unpublished ( 1966 OP Tituu61L.V Tituu61L.V The Innalatom of Fibrous Dusts Iru 3. ttertert SaSa. . 255 Aki previously zbestos zbestos is cited suggests that that the too high high Our Our studies studies TLV TLV TLV for for are hovehove $ FERRIS .. Personal Communication ( 1946 srus 5 DREES W M DALLA VALTE I. Ebas M MallFA and R. Sivas A Study of Athettosis complete enough ever not yet complete enough to warrant a + nal conclusion We cannot eliminate the IM 18 Asbestos No. U. No. U. 5. Textile Inductes Public Health Bulletin GGoovvtt PPrrintiing nting Office WashinWgtaonshingWashington ton DC Received June 201 1010 ua laeds oe ere custs <* eX. sanged oe 1035- ng use ntinues on inaspe ote is aish United Errata L.H.A. In the article The Assessment of the Work Place Prerequisite to the Diagnosis of Occupational Chest Disease by Kenneth M. Moise ( L.H.A. Journal 135-143 March 1967 several errors unfortunately appeared en page 139. In the text table in hand column the time for item 3. Misc timbering bit change etc. should have percentage read 457. Im- mediately following this table the calculation for the weighted average concentration TWAC should have been TWAC = 38.5 ^ 4.68 + 6.5 X 1.64 1.64 3.50 0.48 +5 ^ 0.88 107.948 107.948 = 24.7 mppe 4.3 X 0.32