Document MJp84m0GejzkXpoyX3e7490m7

FILE NAME: Union Carbide (UC) DATE: 1975 Dec DOC#: UC397 DOCUMENT DESCRIPTION: Trade Journal Article - Handling Asbestos Chrysotile Asbestos in Plastics , IA' 7^JC ... ^ /f Ac-* td ,, < r' .a JOURNAL OF PAINT TECHNOLOGY - . .. j . . H a n d lin g A s b e s to s r i.rr r*-' 7VrrSv`5vSiSS`'nfV' J*' 'A';.. "* <- t.O. C h r y s o ti le A s b e s to s in P la s tic s `*y~: rv;s *g0ir& -fc -.v. -J ohn L. M yers & y : - ^ ; -u . ' - ' . ,' Aj ;'&'> T'V*/*"" ' . .. ' J''r ;v.''j'1,.'i!'_ 3*' 1-" '; Union Carbide Corporation* :f .^V e 3 - Vv'i, s***, JT '..' t& x{:r*i ,i,::>' .0.1 ?<>f iu ..-^ ss ^ .* `";V''-:*ac *. 'bi;;,,^jv;>.'?-Vi^5fiA'id s i.' :hr>_- kit:A.-j.*! ii'-.'v,-;V..;S ;?'. '"'^-`*1 *& 3 ^ ' r-'- *r-v` : . hftv '"Kxzaii. :.) J* *>t v* b e t s r i c i f c f r t * r. . ;--vr~w! #t-fy7-*^s> . . --./. -..j-, *v. *.r, ja- i > ~ r . v ' "TI - ?-J -*';f'- T '-''".L*4 . -A--s-h-a--g--tn c---h a-s --rofi-a-l-u--n-d--a- an-r--o fl>t dHeaaall-or.fattention and p--u.b..lii!c-iit.y:. iin, r-eJc,e: n.t. year-s n~ , V ' ; i F*"; ; floor tile and in phenolic molding especially after it was designated a "target health hazard*' by OSHA and a hazardous air pollutant" by the EPA. Many of the articles on asbestos by compounds. It is also used in other the press have been emotionally oriented or distorted and, in some cases plastics such as polypropylene, poly stories have been sensationalized, based on obvious misinterpretation of facts' ester, nylon, melamine, epoxy, sili The use of half-truths or unsubstantiated statements has led to general con cone, and vinyl Asbestos provides a fusion and the unfair castigation of asbestos and products containing asbestos valuable function in such products'as The purpose of this paper is to put th e matter of asbestos use and asbestos brake linings, clutch fadngs, electrical hazards into a logical and practical perspective. In this paper, the different types of asbestos and their many uses are discussed, long with government ' -components, automotive parts,-furrii-' regulations controlling the use of asbestos.The health hazards associated with ^ture, boats, sealants,* coatings, adhe asbestos, both occupational and environmental, and some industrial -ex sives and mastics. The most important perience with air sampling and dust control^ measures ere also covered.','-.: .i}'crd3 j- v 4 ---U>-""tv'*'" WTvvn*?.i*^,,-itt-mw.ii-'i: KEY WORDS: Asbestos; Plastics; Air pollution; .Toxicology.V ywr^?, -functions of asbestos'in plastics are re inforcement, dimensional -stability, heat resistance, flow control, and gen ' ` t,`J .k`> -iiv.'fc- try.?.---" . W eral-purpose Ailing. Most of the fuhe-' tions are supplied: h y ': short-fiber chrysotile- asbestos' fiber,' although What is Asbestos? --_ . - - . . . - .. C. . * Asbestos is a commercial or generic term used to describe six naturally occurring "asbestiform" minerals that are fibrous, hydrated metal silicates. The six varieties are divided into two - classes--serpentine . and amphibole--. biased bn their crystal - structure. Chrysotile is the only member of the serpentine class, while the amphiboles include croddolite, amosite, aniho- phyllite, tremolite, and actinolite. Qurysotile is by far the most-used variety and accounts for over 95? of U.S. consumption, as noted in Table 1. Croddolite, also known as blue as bestos, is imported from South Africa. Because of its high mechanical strength and good resistance to adds and alkalis, it is used to reinforce a limited variety of plastics w here its pronounced color is not objectionable. Amosite, also imported from South Africa, is used primarily in th e rm a l Preamtcd at the Golden Gate Society* Man* atrement Seminar h d d in San Franciaco. Grill., June 16, 1975. * Metala Div,, Nianara FalU, N.Y. 14502. Insulation. Although there are some deposits of anthophyllite in the U.S., most of it is imported from Finland. longer chrysotile fibers and other as bestos varieties are' sometimes re quired for particular properties. . I t is used prim arily as a filler for-- polypropylene and in insulating ma Why Use Chrysotile? terials- A - comparison of the four Among the several advantages of 'varieties Uofi awsbuewsttols wWMhiJcUhJ UarCe (oAf OcoOmU-l.V^;, chr/ywsoutril*e, wwahaiicvhu set uit a^p4aUr\t' UfrWomUI m erdal importance is presented .-in I- ; '^ >e amphibole' minerals and account T TV atbHllee 2O. ITtj smhIuouu.U ld bl ue notedJ xthl.axt t.1h.ere-- - vfA o*r > -iitfse wnaiidl em spiw renaudil amnudil inc-- re---a--s-*ing .u.s. are significant differences between age, are world-wide availability,' m e chrysotile and amphiboles with regard chanical strength, flexibility, positive to chemical composition and certain surface charge, low iron content,'soft physical properties. . ness, and low refractive index. I t is i.-rr ` .. ,. Where is Asbestos ... , Used and Why? . , Asbestos has served mankind for more than 100 years in a broad vari conservatively estimated that chryso tile asbestos is used in over 3,000 ap plications and, in most of these appli cations, it is an essential lngrHiwnt for w hich'no replacement is readily available. ety of applications. The genera] areas 'in which asbestos is used in h e TJ.S. are shown in Table 3. Based on infor mation from asbestos producers and consumption surveys, it is estimated th a t th e plastics in d u stry uses about 33* of the 800,000 tons consumed an nually, which makes it the largest single user of asbestos fiber.. The largest uses of asbestos by h e plastics industry are in vinyl-asbestos The information in Table 1 shows that the use, of chrysotile asbestos and its share of h e total market are stead ily increasing. This is due partly to technical advances permitting die broader use of chrysotile in plastics and the general decline in the use of asbestos in certain fireproofing and in sulating materials. In addition, there is increasing evidence that croddolite and amosite a re more hazardous to Vol. 47, No. 611, December 1975 Table 1--Apparent U.S. Consumption of Asbestos, Tons* Year Total '. 1 Chrysotile Amoslte Croeldolite 1967 720,58$ 686,044 (95) * 12358(1.7) . 1968 81736$ 775,711(95) . . 20.467(23) 1969 784321 749,708(96) 1*7 : 14,618(1.9) * 1970 728.1S1 w 695.770(96) > / , " 11261 (2.0) 1971 758371 1972 808354 r'-y r () Information bated on Bureau of Mines' Minerals Yea (b) Percent of total shown 14317(2.1) 15,965(1.7) 10358(13) 8.936(12) 6,95$ (0.9) Table 3--Apparent U.S. Consumption of Asbestos By General Use Areas Area of Use Percent of Consumption Construction ' ;_ , .40 :r..\ Floor tile . 1 . .!` Felt p a p e r . ' U -'J _ __^ Friction and packing ? ;,, ^ " 'l4 1 l . Insulation l x * i ^ . ":' -2 '.f .3* T * . - ** tu* -.<4 .* :& ' human health than chrysotile.1 Since V'.'o r'ca__u_s_etd-_^s_oile*l%y*r'rby_t athe_i*n*h1_ail_ait*io1n of ''Hr .. oers . . of the International Agency for 1970, the use of croddolite in Britain ' asbestos fiber.*. Another im portant con-' Research on Cancer (a division of die has been restricted after a panel o f. sideration is the relation betw een World H ealth Organization): "There experts "concluded there was suffi ` cigarette smoking and lung cancer, as is evidence of an association of mso cient evidence to suggest other types reported by D r. E . C. Hammond and thlial tumors w ith air pollution in of -fibre should b e substituted for IDr. 1. J. Sehkoff.4 In this Study, they the neighborhood of croddolite mines croddolite whereverpossjble."*,. '"reported that:. "It seems' dear, then, and of factories using nuxturesof -as-; , firat lung cancer is uncommon among bestos fiber types. The evidenoete-7 What is the Asbestos Hazard? , ' asbestos insulation workers who have lates to conditions of many years'Jigo. *no history of dgarette smoking and There is evidence of no excess ride . It is readily accepted that asbestos, - th a t if 3he risk Js increased, such in- of mesotheliomas from asbestos air like many other foreign bodies, can : crease is not great" A 5 - *lrus: pollution which has existed an t h e , cause disabling lung damage, (pul-,: -'-: V. `ritrs K---, "-neigbb_o_rh-ToLo' d__'o__f__c_h_r_y_s_o_t'flelimtl aimo-lj monary fibrosis), commonly referred S p o rte d a ffile to as asbestosis. This disease and bronchogenic carcinoma (lung can cer) are the two most common as bestos-related diseases. It is important to note that, based on epidemiological data, these diseases. have occurred. primarily in workers with high, long-' term exposures to asbestos dust. I t is of further interest that one noted re searcher has reported that neither of these diseases is peculiarly related to cience ^ ^ ^ e K o n i a - tnenoma * an extremely rare cancer ^ - -"u-rb-in- a-hd 'ruml- - ' of the lining of the chest (pleura') :1' . causes.of which have not-been estab-. the abdominal cavity (peritoneum ). .'. .' fished. There is no evidence of a ride, In contrast to the lung diseases,there.")::.; .to the general public a tjre se a tT !;^ . is some evidence -that mesothelioma *. T h e same body quoted above has can occur after brief exposures to ' -also concluded that there is, a t pres relatively high fiber levels. . ' ent, no evidence of lung damage by According to die 33-member Ad visory Committee on Asbestos Can- ',; t-i.Tr *; v: asbestos to -the general public; and. such evidence as there is does not in dicate any risk of cancer resulting from asbestos fibers present in water, Table 2--Comparative Data for Asbestos Minerals*;) beverages, food, or in the fluids used Formula * J' Chrysotile Croeldolite Amosite '' Anthophylllte 3Mg02Si0:'2H>0 Na-OFesO. 1.5M g05.5F e0 7MgO 8SiO. H ,0 : . t - . 8SIO ,H ,0 8SIO. H.O d aacT pc' U -b p Composition, % . - - . . . . * ^ . *Ti. , . " " V ' . SiO. " 37-44 . . 49-53 ' - ' - 4 9 -5 3 * '*' 5 6 -5 8 * ;-: Mgo ;' . $9-44 r. 0 - 3 -'"' > 2 8 -3 4 * V , FeO Fe.O, . ' * 0-6 " ' " ' ' ` 0-5 13-20 ' 3 4 -4 4 ' ' --"3 --12 17--20 . " * ' ' ' Al.O, . - 0 - 2 . * . --* . 2-9 . 0 -2 H ,0 ' .12--15 CiO ' ' "0--5 2 -5 -2 ^ 5 ' S < W **Tlo !i''*: - -- N a,0 ' CaO+Na-O r ' . *' .. ' ' * ' ' 4 --8 .. ___ . -- . * v i.i r / "i . : \" . v. 0*--/ . *3 ' . _ * f Crystals . . . . Color . ... Texture - - Flexibility . Hardness, raohs Fiber diameter, A Tensile, mpM . Surface charge , Resistance to a d d Resistance to alkali Fine fibers Cray gieen Soft silky Very good 23-4 180-300 800 Positive Poor . Good Brittle fibers - Prismatic Prismatic Blue - Cray/brown Gray Harsh : ' Harsh ... . . Harsh Good. . -1 Good Poor _ 4 ..... - 53-6 - 53-6 600-900 , . 600-900 600-900 600 . . .200 . . . . . < * Negative.. Negative . ; Negative Cood . Cood . . _ . ) Vry good Cood... ... . s Fair . . , . G o o d /-- (a) Sound: Modem Flasks Encyclopedia (I97S). and Encyclopedia of Chen. TechTM VoL 2. While there seems "T obe agreement ' that ' the public 'is .not :in ~any present-danger- from asbestos,"it is also recognized th at excessive,Tongterm occupational exposure can cause -serious health problems. Also,-if man m ade emissions are not controlled, then ' environmental contamination ' could could approach harmful levels. During the past two years, significant legislation bas been-enacted b y ;th e Federal government to reduce-and control occupational exposure to as bestos fibers and to minimize fiber emissions to the environment-. Addi tional standards or regulations have -been proposed o r enacted by -many states and local governments.'1* - /. L X JW f l ' tO-bV ' -'.i.-.-, . . Summary of OSHA Regulations r?:*- - - *--*.:</. *.'.r - t ' The W illiam-Steiger Occupational Safety and Health Act of 1970 be came effective on April 28,1971, with J ournal of Paint T echnology the following Congressional purpose: Improper interpretation of die reg EPA Standards "To assure so far as possible every ulations has created many miscon working man and woman in the na ceptions about equipment and pro W hereas OSHA is responsible for tion safe and healthful working con cedures needed to properly use the protection of the worker, the En ditions and to preserve our human asbestos. If exposure limits are not vironmental Protection Agency (EPA) resources." The Act established the exceeded, -there are no further com is charged with improving die en Occupational Safety and Health Ad pliance requirements except fo r med vironment to which the general public ministration (OSHA) within the 'De ical examinations. Medical examina is exposed. On March 31, 1971, as partm ent of Labor, which has re tions are required for all employees ----' bestos, along with beryllium and sponsibility' for administration .and in any occupation exposed'to airborne-v '' mercury, was identified as a '"`hazard enforcement. Research and related. concentretions of asbestos fibers.. The ; ous air pollutant" by the Admimstra- functions are handled by the Depart- ! examinations are relatively simple*and f Tor .of the EPA. .'National Emission. ment of Health, Education and Wel . ' should cost no more than $50 p er Standards for asbestos were then pub fare (HEW ) through th e National .fry** #>* /' ` - .Tit *.v ' . ... ,,year, p e r ^ l o y e e ; . e ^ ^ ^ ^ n i ^ 2`. lished b y EPA in the Federal Regis- - Institute of Occupational Safety and ' ter, Vol. 38, .No. 66, April e, 1973. Health (NIO SH ). Five million em Respirators and special ckrthing* Although no numerical emission stan ployers and 60 million of th e nations are required in die construction trade . dards were established, -operating ori- 80 million workers are covered by for the spray application of insulation " term are prescribed^- to prevent 'or OSHA. Specifically excluded from .and fireproofing materials, and for-the ' limit asbestos emissions to -the out coverage are government employees removal of such materials. This spe- side air from asbestos mills, roadways, and operations which are protected d al protection is -not required for any- oerbain manufacturing 'operations, under other federal health and safety, other use of asbestos unless exposure building demolition, -mid die spray-on laws. In a news release issued January lim its axe exceeded. This is also true application of materials used -to in 4, 1972, OSHA announced a Target- _for jo fh er items such .as specially sulate o r fireproof equipment and Health Hazards Program aimed a t equipped tools, change rooms, clothes machinery. The law further -requires improving health factors associated ' kundering,randw aste disposal. Res- that spray-on materials -used to in-\ with working conditions. H ie follow- . ^p irato rs are not ^. substitute for eu sulate or .fireproof buildings, struc ing five substances were designated " ' gineering ;controls, but the law.allows I tu res, .pipes,Tond -conduits shall -con- - to be the focus of initial and con-' their use while controls ^are 'lid n g tain less than JS .asbestos o n a , dry-, eerted efforts by OSHA and NIOSH: implemented, in ' -special situations weight basis. This should significantly asbestos, cotton dust, silica, lead, an d where , controls -are not -feasible or . . reduce emissions^ to which die gen-. carbon monoxide.'.-";;"... M-.'i*. adequate, in emergencies, and f o r in - .; eral public may be esqxwed, especially frequent short-term, job assignments. . 'in large urban areas. At the present time, new standards - Caution, labels are required on prod- { . - the Administrator (rf EPA) have been established only for asbes ucts containing asbestos except where has determined that, in order to pro-' tos, although, of die 8,000 toxic sub ..the fibers have been modified by a vide an ample margin of safety to stances on die NIOSH list, only 500 bonding agent or other m aterial to protect the public health from as are covered by standards and many prevent dusting during any normal bestos, it is necessary to control -emis of those need updating. The new subsequent use or handling. Besides sions from major man-made sources Standard for Exposure to Asbestos raw asbestos fiber, products which of asbestos emissions Into th e atmos D ust was published in die Federal require package labeling could in phere, b u t dial it is.n o t necessary to Register, VoL 37, No. 110, on June 7, clude: dry acoustical spray products prohibit all emissions.X 1972. The basic exposure standard is and joint cements, unsaturated roof- . "In this determination,"the Admin an 8-br tim e weighted average ing felt.an d textiles, and some, in istrator has relied on the National (TW A) of five fibers, longer than 5 sulating products made w ithout ade Academy ..-of 'Sciences' .report o n ,as- ; micrometers, per cubic centimeter of quate binders. T he labeling of a prod- -. " bestos, which concludes:'""Asbestos-is air. The TWA limit is to be reduced uct does not prohibit its 'u s e . It ` too important in our technology -and to two fibers per cubic centimeter on should be noted here that in a t least economy for ite essential use to be July 1, 1976. A peak concentration 90S of die products containing as stopped. But, because of the known of 10 fibers p er cubic centimeter is bestos. die fibers are solidly locked serious effects of uncontrolled inha -not to be exceeded at any time. All into -the product thereby presenting lation of asbestos minerals in indus of the fiber concentrations are those little danger of dust generation dur- . try. and uncertainty as to the shape to which an employee may b e ex ing normal use and handling of die and character of the duse-response posed w ithout protective clothing and product* ..... - curve in man, it would be highly im- equipment. The first basic require ment of the new standard is monitor ing to determine whether or not fiber concentrations are in excess of die . exposure limits. Some asbestos sup pliers provide a monitoring service to customers, and a similar service may be obtained fyom state health depart ment officials, insurance canters, or private consultants. The law requires that monitoring be repeated as nec essary to ensure that employees are JOHN L. MYERS. Marketing Manager for the Calidria Asbestos Group in Union Carbide's Metals Div., received his B.S. Degree in Chemical Engineering from Purdue University in 1951. Joining Union Carbide that same year, h e served in th e N u c le a r D ivision until 1966, w hen he b e cam e a Research E ngineer in th e asbestos group. H e was promoted to his present position in 1970. - . . : . K- i. -; J- ---V"! "vL;! .K ?" -- . . ' c-4* . " 7* 4- not exposed to levels in excess of die exposure limits. Vol. 47, N o. 611, December 1975 prudent to permit additional con tamination of the public environment with asbestos. Continued use a t min imal risk to the public requires that the major sources of man-made as bestos emission into the atmosphere be defined and controlled.'."V. ; : V..'' ' .'>'5 4 ' - *-.<!"`\-c' \V< v What is industry Doing? Table 4--Typical Air Sampling Results* . Celling . TypePIcnt ; Concentration, Or Operation Asbestos Fibers/cc Dust-Control Measures Asbestos producers and users are spending a considerable amount of time and money on various dust-con trol measures. Conventional means to achieve minimum dust levels include: The Asbestos Information Associa- ' tion/N orth America reports that, dur bag disposal and other asbestos w aste, ing the past 30 years, the asbestos in (a) `Source: Union Carbide C arp,, from air monitoring report, .* 'handling, and automatic bag openers.- dustry has spent millions of dollars to - TJnusual -innovations In c lu d e :p e l-: improve mining, milling, and manufac letized asbestos, special packaging, turing methods.* The establishment of and treated products.'i}ri.-;.U safer working conditions has been a - Only short-fiber chrysotile is avail prime target and this work continues able OSHA level is 10 fibers/oc. In able as pellets, bu t this product serves unabated and in dose association with most cases, the TWA exposure level a :-fair portion o fth e . asbestos m arket government agencies and independent would b e well below OSHA 'stan-. T TeJlets-m ot-only reduce dust during m edical researohm.A^iT'Xi t f ; m.*.-/ dards. Most of the data were collected^^conventional handling h u t they-are T h e ultim ate goals of die asbestos before th e installation'o f ^ iy ^ e i^ ^ ^ ls o .a i^ a a b le in baffle hepper cars and'.: industry are: Reduction of work-area dust-control measures: Monitoring transferred and used in totally" dust to minimum, levels; Protection . `-ten systems..,Bailing leaks iririhe' of workers from asbestos-related dis ditioris rare caused fry m aterials -other-'- rsystenvdust in work!areas is v irtu al^ ' eases; Maintenance of environmental than asbestos. This does riot preclude eliminated. ;U sedririn;bulk,- asbestos., emissions a t levels low enough to pre the-need for controls, b irt it -could .* pellets - abo reduce -shipping *>icosts,' elude pubhe endangerment.' .''sU1; 'Achbangoe their acope and fanciUlitat*e coAmn.-' - -elim--inaitie ' w arehouse'., storageS-arid. ' pliance with government regulations. -handling, facilitate automation, reduce." Air Sampling .7.:: "-.' Because of "bad pressi" asbestos' is clean-up, and eliminate bag handling' frequently ordered out o f use without and disposal. The pellets -contain no In order to comply with OSHA . regard to 'w hether ;or -riot ^'hazard hinder and are .friable enough to b e , standards and to determine the need actually exists -due ;t air contamina dispersed in dry ionn-.or.m aqueousV for dust control measures, air monitor tion. - If acceptable dust '-levels 'are ' o r resinoussystem s with conventional ing should be conducted in areas feasible, there is no need to replace high-shear grinding equipm ent where asbestos is regularly bandied asbestos at the expense of product . Several types of special packaging or used. OSHA standards require that quality or economic penalty. Cordon are currently available, and suppliers '"all determinations of airborne con Everett of EPA points out that In consider customer requests for -unus centrations of asbestos fibers shall be formation on the biological effects of ual requirements. The floor tile indus made by the membrane filter method asbestos is very limited and that die try can obtain asbestos in plastic bags at 400-450X (magnification) (4 milli effects of many substitutes have not which can be added directly to.-the', m eter objective) with phase contrast been investigated a t all. Before as compounding operation. Asbestos -in : illumination."10 The equipment for bestos is replaced, it should be cer bleached paper bags assembled.w ilh collecting, air samples .costs less than - tain that a safer alternative is' avail water-soluble glue and printed w ith $400 and is readily available. A'phase * able.?* v/- water-dispersible rink: can .be added : contrast microscope can be obtained Obviously there are more -people; directly -to paper-m aking.finishes o r for as little as $600, or an existing exposed to products containing asbes acoustical tile formuhtions. ; microscope can be modified for tos than there -re to raw asbestos - Although "wetted" asbestos^is not "counting" the asbestos fibers m com fibers. As noted previously, more than generally -available, most . suppliers pliance with NIOSH criteria." . - 90* of the asbestos used in this coun are working w ith customers to pro-' Air samples have been collected try is in products in which the asbes vide "dustless" products. W hen justi-. and analyzed on a regular basis by tos -is "locked ' in" -or bound "with ce fied .by market demand, asbestos can the asbestos industry for years. Ex ment, plastics, or other binders, so be treated with water, mineral spirits,- cept for a few applications where dust that there is no release, or at least no glycol, or other materials compatible control is an engineering problem, in significant release, of fibers in work with the application or system. dustry is finding that dust levels are already within acceptable standards areas or to the environment. Materials or products with lodked-in fibers .T'-VS.V!.-' or- that minimum changes are nec would include: floor tile, polyester Conclusion essary to achieve compliance. Al though data on many asbestos/plastic resms. phenolics, sealants, coatings, brake linings, friction materials, rub Asbestos is one of industry's many raw materials which involves a po applications are not available, the ber, roofing compounds, and rein summary in Table 4 is typical of our forced plastics. Since an abrading ac measurements of dust levels during tion on some of these products could asbestos handling in various types of release asbestos fibers, appropriate plants and operations. The dust levels monitoring and/or control measures reported are ceiling concentrations, should be instituted if it is thought and it should be noted that file allow- drat su d i action would release fibers. tential hazard when not used with reasonable respect and care. Although all forms of asbestos are recognized as 'hazardous to health when inhaled excessively, there is growing evidence that crocidolite and amosite are more hazardous than chrysotile. Fortunate- J ournal of Paint T echnology ly, die plastics industry uses primarily chrysotile asbestos and, in most prod* ucts, the fibers are -locked-in to pre vent airborne contamination. Al- though asbestos dust levels are gen- . . erally lower (ban expected, industry .7> . - ; . -; continues to expend large amounts of , time and money to further improve die quality though the rently in 1 are required vironmental ` Chrysotile asbestos is an important and necessary raw m aterial, vital to the nation's safety and economy; and, w ith proper control, it can be used - \ safely and in compliance w ith govern- ; ment regulations. M edical, identified" <;- -J>.'.j government, and indusbial peBonnel/'V-V ^ ^ m ust continue to work closely 1o-i*.;y ' gether to establish reasonable expo-. sure lim its, provide safe -work areas,-; and ehmmate any possibility of public.j __ . , endangerm ent ] -y -.-'V ~ :*:' ; . * ................. ........................... _ S ifte S (S) W right, G. W ,, statement ~before TJ.S. Dept, of Labor, Occupational ' Safety and Health hearing on posed occupational asbestos dard, March 16, 1972, p . 3. (4) Hammond _E. C. and Selikoff, "Relation ' ` " '* Risk ated Workers _ at meeting of the Working Group to Assess Biological Effects of As bestos, International Agency for Re search on Cancer. Lyon. France (Oct. 4,1972). (5) `Report of the Advisory Committee on Asbestos C a n c e r s Brit. J . Industr. (6) "Asbestos, . (Oct. (7) "National Hazardous Air Pollutants," Federal - ; R e g iste r38, No. 66, 8820 (April 6, 1973). - .. * - -- . (8) "Protecting the Asbestos Worker," r1 Booklet No. 101D37, T h e Asbestos .. Information Assotiation/North . America, p 5. ' (9) Selikoff, I. J.. Industr. Medicine, 39, No. 4. 21 (April 1970). (10) "Standard for Exposure to Asbestos Dust," Federal Register, 37, No. 110, 11320 Qune 7, 1972). (11) Bayer, S. G., et al, "Equipment and . Procedures for Mounting MiUipore Filters and Counting Asbestos Fibres by Phase-Contrast Microscopy," Bureau of Occup. Safety and Health. U.S. Dept, of Health. Edn- . cation, te Welfare (Feb. 1969). (12) "Asbestos Health Question Per- - plexes Experts," Chem. Eng. Mews, 18 (Dec 10, 1973). - (13) Myers. J. L., "Calidria Asbestos Pel- . - leu," ASBESTOS (Oct. 1971). . Vol. 47, N o. 611, December 1975 '*> ' _- 'VV ' j J ' j S * '--if*: _ . --V , *- w* :VS* - >- _> .rrf -j i, v ~ Asbestos Information Association ; : North America - ^ V v \ 1660 L Street, N. Washington, D. C. 20036., -