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FILE NAME Corning OC DATE 1991 DOC OC344 DOCUMENT DESCRIPTION Medical Journal Article - Fiber Toxicology and Occupational Health 03/27/92 16:29 002 aarvice by Pfizer Laboratorias . CAE A eae et * et, ' - ' fl " Pfizer Labs Plizet . . Volume 6 lue $ Ratsot% 3 SSS bot v -esn em om nat Fiber Toxicology and Occupational Health The Integration of Research And Health Programs William B. Bunn MD JD MPH Senior Director Health Safety and Environment and Vice President Manville Sales Corporation Denver Colorada Joel R. Bender PhD Vice President Health Safety and Environment _ Fiberglas Toledo Ohio The potential toxic consequences Involved in the manufacture and use of manmade fibers especially fiber glass and other made vitreous fibers invoke the sense that we have been here before But the manmade fibers are physicochemically unique they differ from the mineral fibers and from each other Unlike the problems associated with asbestos in which the untoward propendes became apparent only after the long and widespread use of the mineral there is continuing and worldwide investigation of the epidemiology and toxicology of many of the manmade fibars The questions recently raised about the advisability of removing remainant asbestos from the environ- potential ment has focused the attendon of phy- sicians and scientists on the for a new epidemic of occupational and environmental lung diseases caused by the newer fibers Isnekground There is growing contention about the risk of caposure to asbestos and the nationale for asbestos removal This was recently pointed out by an article in Science 1990 by Brooke T. Mossman and her colleagues They raised the question of whether there is a potential for a third wave of asbestosrelated disease among persons neither engaged in manufacturing asbestos among its end users The article was hotly debated in the lottons to the edl tor of that publication The paper concemed the relative fisks of removing chrysotile the pre- dominant form crocidolite and other forms of asbestos from buildings The Editor's Comment It is premature to write an epilogue for the chronicle of asbestosis There are chapters yet to be written and precepts begging formulation But the jessons already at hand need to be indelibly taken to heart by every physi clan and by every member of society is clearly established that to amphibole asbestos fibers imparts an important risk for exposure disease and an important and specific risk for fibrosing lung mesothelloms Furthermore there is little room for debate regarding the synergy for bronchogenic Carcinoma when such an exposure coincides with cigarette smoking clinical establish these tencts as facts required more than a genius for clinical investigation it required zeal and perseverance on behalf of the worker at skto convince the skeptic and overcome the inertia inherent in any allempi to shift moneys from profits to welfare We have come that far Asbestos exposure in the industrial setting is regulated no more than two fibers in 10 mL of air is permissible Furthermore we have held sors of exposure accountable after the fact for events that occurrepderbpeeftorrae- the levelos f accountability measured in tens of billions of dollars 4/ Continued on page 2 wus yey 2 a strela oe : L^ ebadence cost wil 2 what antega ned He yee vote yg HE wots an kinesi kinesi kinesi Les, fo! . HN Woe oe ad 1 eter . +, keabstdg ass 2 , ** ** ** ** tril Ee ya rm . yk 1 a| the j fiesta fiesta ae eon . . . 2, . t 2, i ; a a wo Mr. ode optt tt fe ar cr) , ee 4 te, arty rn 3. re oe oe hs . ** TEER Oe ee ait! 07 7 ay Sr a = fy ~ 0 bs seth tera ** gt poo an a . Ti ate ati a a 7 te tre ae LO Parl ' ae oe toe Peed Pay - 0 toy br br he ed pias oF v4 oY n aS. TEE Me ar ae tre. wey ~ eo - m3 wot th oh r Yrs ! A P- , so ' re fot ee fee a . ' hae toy on t -- 41 . ne Vee d d Sop Be sie get. Cn a) an a ve 7 n Aon. bet 3 Maite fae 2 lage eo . Tote . Aae s e Ley let ce oad af fl ~ a ae had ae + tet fam W oa he RG Tay Pend wo} 2 I 1 7 4 1m, bye . If +. 1 ao is ' a s ts oars Sd Saye aed 4 wa K woe owe 1 ae % . aaa ad Lo . 111 . - oon 8 t . 4 apy foyer. toe . wee ; Mek z . poe ae of top rs ier ' rare pos, . - i on ee ify : wo we wa. or i obo i . ' - at Looe ; . . Cigar, Baa be BO re bre Le iy 1 1 71- aoae te Jo foe . abioy ry ot oye an - ail Mat ah 11 ue ' oe reer rors + Roa ve ait ret tee . : oy Me toe y PTE gay, mb fa oo the my yr Cn are aa LESS pose SPASTh SSeS SS 5 03/27/92 16:29 003 reacdon in a group of miners That attention led to social reform in occu- pational health regulations and compensation primarily Worker's Compensa don for silicotic disease processes Coal worker pneumoconloses have been well recognized since the early 1800s but it took a century to awaken the public conscience then only after the Farmington mine disaster of 1968. The water mark of mine safety in the US was reached with the enactment of the Black Lung Act of 1969. Other pulmonary diseases such as byssinosis and berylilosis have the subject of regulation liugation and debate for many years issue is somewhat clouded by the fact that other including asbestos-- art prosent in these areas In animals erionite appears to be a polent mesotheliomog^nicagent than is asbe tos No cons hase been n rs eacu heds on acceptable levels of occupational exposure to the fiber so no recommenda- tions have boen made nor have definl- tive regulatory reviews been conducted for erionite wollastonite or attapulgite Wollastonit In such products as ceramics Insula tion and wallboard wollastonite- a monocalclum silicate fiber used useful for assessing its hazards Overall the data suggests that two profiles exist one for origin the other for fiber length The data on exposure is vui able but dust levels for certain opera tions approach the standards for nuisance dust 15 mg total 5 mg . respirable MEN MADE VITREOUS FIBERS For more than 50 years the made vitreous fibers MMVFs have been produced and used in a wide variety of applications They are synthetic inor- THE EPIDEMILOGY AND TOXICOLOGY OF FIBERS Natural fibers Asbestos is a naturally occurring mineral fiber the toxicologie and epidemiologic effects of which have been well documented Standards for work- place exposure and work practices exta in most developed countries However theries a need to evaluate the risk posed by other naturally occuring fibers eg crionite A body of information is emerging on these fibers but specific regulations exist in only a few countries Erionite Zoollte is a naturally occurring crystalline hydrated aluminosilicate erionite is a crystalline fibrous form It is found naturally in the westem United States Turkey South Africa and elsewhere Erlonite has very limited commercial application but exposure occurs because It is a contaminant in the min- ing and manufacture of other zeolites which do have commercial value as molecular sleves and in exchange processes Erionite can produce tumors particu- Early mesothelloma In mice and rats that Inhale it Villages near Turkish erionite deposits have been found to have high Incidences of mesotheliomas but the * At Gauley Bridge West Virginia workers were exposed to high levels of crystalline silica when tunnelling through a mountain with a high quartz content The minimum exposure necessary to produce ellicosie was then thought to be two years but a number of workers with less than two years exposure developed an acute pulmonary process and many died The event led 10 the recogniiton of scure silicosis and ing gered a deeper scrutiny of the clironic effects of crystalline silica Man fibers have similar irritam effects the extent ofwhich depends on the diameter and flexibility of the fiber as an asbestos replacement It is @ durable fiber but it has less tensile strength than asbestos Toxicologic studles of wollastonite are limited the only inhalation study in animals failed to produce a significant response Injection and in vitro studies suggest that wollastonite is less toxic than asbestos Epidemiologic studies of the neoplastic potential of wollastonite have not been conducted and studies of its fibrotic potential are limited Overall the health studies of wollassonite are sparse Exposure levels vary widely with the application and the industry fiber levels of up to 40 to 50 fibers cc have sometimes been reported Attapulgite A fibrous aluminum silicate and mag nesium silicate attapulgite is used as a thickening agent and an absorbent as in pet litter It is mined primarily in the United States The fibers are shon and relatively thin although the size varies with the geographic region of the deposit The effect of attapulgite in animals has varied significantly from study to study These differences appear 10 be related to the origin of the fiber Inhalation studies in animals suggest that the longer the fiber the greater the toxicity This result is consistent with injection and in vitro studies although there is considerable variability The epidemiologie data on antapulgite is very limited and does not yield data ganic and amorphous the family is sometimes referred to as made mineral fibers MMMFs but technically MMVF is more correct There fibers are all created from molten masses of raw material under highly controlled conditions Fiber glass is one MMVF which also includes rock mineral wool and refractory ceramic fiber RCF Much more is known of the epidemiology of vitreous fibers than is known of other made fibers or non- asbestos natural fibers In addition chronic inhalation and other toxkologic testing has been performed Specific standards do not exist in the United States except as nuisance dust but broader standards are currently under consideration and multiple international bodies have already reviewed the sci- entific literature on made vitreous fibers Fiber glass Two basic forms of fiber glass are in general use wool fibers and textile fibers Fiber glass was originally developed in the early 1930s for use in home panel filters and home insulation textile fibers appeared commercially in the late 1930s followed by diameter glass fibers in the early 1940s Wool glass is generally used in thermal and acoustical insulation These products include duct insulation pipe insulation ventilation airfilters roof insulation and insulation for 3 Acer Ah mate, Be Wrath. geet plances plances d seitgessun oad Ag oe ra) ti 4 Yoo, if : ae Den seg Glass fibers are also meublem^ meublem^ natera of less than one a 5 f diameter misterial is pru ' & 2 Bb eaere we wey, 3 veo CaPW a Ya es a Eee te angist y - + a Ye yh + wh 1941 }e ; te : ay ted Staten Staten limited yyentities ta Gal oS ee, constrite was than % of the wid ide pluss productos purpose fine5 ver is limited to use in speciuly filter papers battery components and sophize al cor **** **** my{ **= taketnaken magnitude was taken PM dae atl taken to Ju SaeEe AN, 4 produci^nAlso trend war nt cated aerospace insulations Textio glass finds wide application erm as a component of cusains Industrial fats- ries electrical yams roofing shingles arvi ie ariefortement for plastics papers rubber and other materials It is generally not of a Health effects of fiber glas chen Skan frritation Fiber glass may mate the R skin of come workers in fiber- peo ing was seasitiz che lung predne were reaction dence of e increas^<d^to pias rel eS or - tunnon musalignant respirare respirare b at Sage te The University of Petrum oe rile hensive mortsliv study our 60 workers many with amneamne roztam ee 40 yeas 92 to we unden glass- and mineral ag ci TOme turing dans 11SK 11SK Pagar fo fy ky waniay Tyo cg as pee Mobod 1935 Ssvertt manufacturing facilities and of soine work so ers who fabricate or install fiber glius ex f Ma^-ardflom exposure and there epe from the 1940s the bad ye kam same group of worst w Pe go waining materials The skin irritation & a a ce possicie Infiammaton is a mechanical sa action te sharp broken ends of fiber that jub or become embedded in the outes ile layer of the skin Skan veactions vary di- rectly with the sire and the suf nest suffnest of the het fiber These with diameters greater than 4 { should be no further effort on the tae woner's dobila ena vefiiteng Bos sure to fiber glass does 101 BenL~ ZED jmd em hung war jmd exe ^ll^skchole a wlaN A Epidemxloric studie LS through 1983 reported in naprapa 1989 with 14 tron analyses in the 1947 The 987 report contured fv De fitat fiime local area mortality per tes for each of the piants The mud wes fundier undated through 1985 with publication in 1990 Through 1987 ) sub are more likely to cause ItioIntion Nespiratory system Greates Greates are the pri eR that are diameter fibers When the mary subject of us epidemiologie malignant respiratory disease and causedstatisucally ~~flfl no significant excess dippeter in jess than 1.0 thefibres usi~fl stud'es involving file glas and other of caths in rny of the 11 plass ally do no cause skin imitaton Normal MMVFs Yem of mousands of worden planus nor in any grupping the da the amritation does not persis for fon mund | ha ten employet ve maza acturing acturing guished the plans on the basin oz | ar 2 can usually be relieved by asing build| Cher giann dvale ju inuisi de lugten Ce lugten glasses no reacle production rezne dep and want water to gently wash ne eve 50 years ago and twe nay and fibers are referred to as glass fluent exposed exposed areas Most worken fird met an ^ ies la addressed the monasty of ir the mannsenp and by IARC | imlavon experienced when loy working wo gand in than pros^>mz^v^ 17 oplate mongh 1981 KTE lin fiber glass lessens over time Allerga Kerarc'ir at the Uls versity of Pitts did show a suistically Significar e soens contact dermatitis has not been associred withexposure exposureon fiber glass bu riwie have raggi sumbat de printality 2 invest : of dists from restiality canes, 2p ED workers from 11 5Tgee worker eroloved in glass and b^rpode of litige rescue.k to the tromifertorey tromifertorey fankas ilgs Cutt fad Ts minera won plants Tosee if the date nured res fimanes dust are sted en me the glen^produzn eragilities rationbij cainveustigsatedeinveestfifgaoterd SAL JE JEZIZONE May be mois s'ler vd by ber Gag 1 yee Blade Blade wee IN were consizem with a 1 > e exptome Worke * nur th eragilities 1 The spesit ut fecula od slut wive i ples Goer, the searchers searchers waves from fiber glass than see office pal y few inay ie foxed en ^,rek olle kepravi kepravi c^ployment The ves Waynan al woners nowele gan z kols^raim termutatermuta u atquogatott otk spoyak spoyak ba laveste oe Loope research- ortygt aro fan DT eaearcfier 1997 Loope HVal Aptoby fur er GAR have com stoly Peetea. set oe LAN OY G1 12:56 of moride sed is a six | pratinle assum ^liomy of excess rats death with with heat of employmentfr te respons simati simati idiual en F ) and die rianificariranifiecare p" stikfine stikfine gla se her ri divers divers These bi 3 Mamiten Mamiten Mamiten have a ocet. & len he 18 * whigh depts on ~ e jurme saray saray tarot tarot fire mass An alle soddi ender way usty usty simrificari simrificari fn dinge is suppo 51 a relatiorehip nerveer ve coe Olaine at les vibro of the hour jr 1919 36 pe published published the diveberani diveberani saptarea saptarea mays fi'erm Py pe PPh. 43ffarizant se yy inay rapatra jes demonnay demonnay apr Kiau ylimbekur sanifested 1947 1947 + poke poke for eyeptate eyeptate of the nose muda 10. 20 1.1 10. 10. nach if during the mania ne handy on warpated warpated warpated ore din to 6 ficc at ar we hae PD they are te large eindere 17 0 Live S^n aban 1349 apts Oe 4 t y Day Day worker Patter er Fer 61 1 Campe Campe Ich t ' } ag toe! 1.42 Y : deam Tat with trige trige vt Samorate de 14 14 The ark is warpated warpated it 1 caption caption avionel avionel 6 gtr Co leampety om 1 fee Fue aps fe oe. ; Bota : 24 FASO gape. draken in schnen died etude wae het mp Th vers Fe workinwogrking et BEIM at 2145 m2 apr ^ at partioppsartiiopsiee veren o Rpo Rppure #bly #bly ce je Terv geteor of the showed that it ling it fate 6.1 huraat as worsvinde ister car amaestri amaestrifiber kitse ..t ert User Susing in Kony A Ae plati~ eplati~ eplati~ e a met ehatan ehatan K^p Mara orta fibers colonial colonial supo dies to len ote PML os Hey te Cp * he r obit. i BA hee min i . ab hitedag eal | en ghiv t eness of tive k ge Piatton og daga ^ 25 eg the branded t vid " & 03/27/92 16:30 004 004 004 Pree yee tei. ee eee eT ce Se ie FG ee eed lung some of the excess cancer previ- ously reported in the University of Pitts burgh study + Other than the statistically significant standardized mortality rate no note- as wonhy morality findings from nonmalignant respiratory disease or mesothellomas associated with exposure to fiber glass Morbidity among glass workers has also been studied None of the Risk evaluation International and US agencies have conducted a number of reviews of the health aspects of glass fibers These agencies included the National Institute for Occupational Safety and Health 1977 the World Health Organization 1984 and the National Academy of Sciences 1984 Recently there have been two additional major reports prepared on the health effects of glass . source the average diameter ranges from 3 to 15 Major application In the early 1900s mineral wool was developed as insulation The fiber is generally supplied in three basic forms loose wool wool bonded a into batotr blanket and acoustical tile and panels Today mineral wool is widely used to control temperature and round Its major applications are in commercial consistentconsistent studies reported a pat- of respiratory disease nor was any fibers In 1986 the International Agency for Cancer IARC reviewed acoustical control products pipe insulation and insulation for auto- tem respiratory impairment found of the Research on mineral After review mobiles ships mobile homes refrigera function of manufacturing workers even among those with extensive exposure made ing the epidemiologic data on over 400 deaths from lung cancer among the tons domestic cooling appliances and a wide variety of other appliances and In the comprehensive study Welll on the respiratory health of 27,000 glass workers in the Euro- Simonato al and the equipment 1.089 workers at five fiber and two pean study by Enterline and Marsh the Health effects mineral plants in the United States US study by The skin eye and upper respiratory ir- LARC working group of the World during 1979 and 1980 1987 stated that the evi- ritations of mineral wool are similar to The researchers noted that the sub- of fiber However Health Organization dence was inadequate to conclude that filaments were thosgle ass jects were generally healthy or small opacities did show on the chest either glass wool glass No evidence of some workers In summariz- carcinogenic to humans Animal studies rays their findings the authors noted of fibrosis or other morbidity was found Several inhalation studies with animals ing that in general the minimal evidence by the IARC panel negative inhalation- have been done at independent of respiratory effects detected in the in- Despite seven animals implantation of research centers Comercialy avall able was used In vestigation which cannot at present be clinically significant is en- studies in microfibers of two special basis minend two of these studies the animals were exposed considered cancer This is the couraging concerning the question of glasses induced the IARC that to high concentrations of fiber for one then allowed health effects of exposure to for the determination by to live year or more and potential of their lives Compared made vitreous fiber A follow Weill glass wool l possa ible human carcinogen Continuous fiber- to out the rest the controls none of the test animals study with controls reported by 1985 and 1990 found no adverse pul- glass was designated Group -It is demonstrated fibrogenesis carcino- in effects associated with work in not classifiable as to human carcino- genesis or permanent changes of the the MMVF industry genicity In 1987 a second majorinternational respiratory system nor did the expo- evaluation of the safety of glass fibers sure reduce life expectancy to a signifi- Organization Experimental studies studied the effects of by the World Health WHO led to the report of the Inter- cant degree Other studies of implanted injected mineral woo have shown Researchers have surgically implanting fibrous material in cavities of national Programme on Chemical Safety IPCS The overall picture indicates or instilled that virtually all fibrous materials can and regardless of the pleural and abdominal animals and of injecting fibers directly in that the possible risk of cancers among the general public is very low if there at very high dosages physical or chemical makeup have However evidence into the trachea In 1977 it was found a adverse effects all and should not be cause such work that tissue changes Including at is any for concem if the current low level of from other experiments indicates that mineral wool is attacked by the uids cancer and scarring were produced by with diameters of exposure continues The IPCS does in the lung This may specialty fibers less than 1.0 Other glass compo- allow the weighting of evidence and the inhalation studies in animals were normally present cause fragmentation imo shorter fibers active or sitions including those used in building weight in their analysis that may be biologically less insulation did not produce such results given greater 1988 the US Environmental Pro- may even lead to the total disappear- These experiments are valuable in the In announced its agree- ance of very fine fibers study of the mechanismis of tissue rdac- tection Agency IPCS conclusion when it ilons but because they are based on the ment with the for the carci- Epidemiologic studies introduction of large amounts of fiber by stated that the evidence is considered Thousands of workers have been em- routes that bypass normal defense- nogenicity of fiber glass ployed in plants that manufactured min- mechanisms they do not justify the con- inadequate eral wool during the 50 years since Its clusion that inhalation of glass fiber is development A number of epi- hazardous to workers As a consequence demiologic studies of workers have been several inhalation studies in animals were Mineral wool wool are done but the two major monality srud- research cen- The fibers known as mineral those discussed above in the initiated at independent available glass produced by spinning or blowing mol ies were section The excess lung can- sers Commercially recently specially ten basalt or the slag obtained from glass found in sleg- and wool work- products and more prepared fibers with carefully specified used None refining ores These latter consist of metal -silicates of aluminum cer ers was the disturbing finding but be related to carty lengths and diameters were in- boron calcium iron sodium vari- that excess might confounding of these studies demonstrated tumor metal oxides Depending on the production phases and to or duction fibrosis by fibrous glass ous bo) * exposures to suchi carcis^gens# #ad asbestos or arsenic in addin^nraz arudies were difficult to control for si smoking for exemple could have contributed to the 150t f 76745861 at There are three broad categor^>ta of tefractory o~ amicfiber RCP kaolu . based fibers in which the clay is obrained by zindag blends of wunire silica and a refractory steta oxide ep zirconia and purity products that are blend of alumnica and allua pr ressed to hmlt the let se of tripssabes that we found in other RCF products products The fibers are produced by rpluring molten mistures mistures The average diameter of the fibois produced in this mare is in the range of 1,2 35 fle fle length can be varied from long fiber down to rized th Fatenen rt cate be 3 . de luge| es ** tf mccain fran Ai ne B *2 Mitta aHeey Te ek ef ea ' qusent at kunne dipurestera zokoan zokoan { { expuan expuan dan 1 the real af lunt nunction tSABLE WAT Me eK a TE Ce erg sundstom with minimal obstruction associated wit q etgazete smoking and mimba inti kate estou with expor j i sure to cervenir ffter boras avmptoms 4^onu">n^b^"ibrenthiessness were }! also found Small opacities te ar un prosent 15 of 594 test TePrimanly DROP 1 | wer relwot to see and 10 sinoking hab &fiPROS, Main sian Rigs an 8 19 oe aods Sa on rumic fibe tomaning tomaning 27 ayarlse silica thathad previously previously been exprivind a high tenger nuet Approximatel M 2501 os were greater than Spam xax in Harnsters were exposed only to sbotini DROP I both the we and the hanger muelles postive controls inhaled 10 mad i it ang there was some evidenx of an " mof claysetile asbr^tosand departe departe essochon essochon with time speak in the indushy that dot with cumulative CONT ec,,eived filtered filtered alt Atotaln tre hans enrage et exposur RCF he is not chear whe he long biologirai significance c the Xhelin RCF fiber developes developes mesotheliomas A conmeligna mis may be of az amal effects apparently sothelial pullteration was TOUK 4 priate ceramic fibers and the study pleura of one of the soberine brei | la libong u be brasi : Rowth from the 3 study wie toma hamster.eegative hamster.eegative hamster.eegative control hangers hangers hangers vegn antung kesims Cyrok gceauG NN S wee ~ ee - Om tm em ce eames enh oe pehue the king oi te exposen nan da^-os revealed pulmonary li mosis li mosis de ap Rose Rose sudy , saa ei maals na siranya and pleura exposed in the PCF rats painologival painologival ; suulus ten slad hang utr^orstand be- hige palmest me Fad a the risk evaluation evaluation for RCF Je modefiomas expondralexponsdrals tenlga and nulignaui lung tumore were end da final results an~- for you 4 rm are) available Cyrologic examinauus of the Major application ** availacic Priinimary reports UN^ - rats sacriftoed at one year showed showed that exposure to kaolin RLF zimous RCF Applications vary but all are used in i care decrease in pulmonary function nigh punty RCP rafer servic RCF lau temperature specialis enviro 1 chat is not ritnically significem m-a and asbestos ali meul ed in pulmonary ah ments Blankets are used primarily as porsinde increase in pleural plaques fibrosis After the fina year the fibrosta fumace and wall liners loote tihe amon exposed workers The progressed progressed nore siowity siowity je used as a filler in packing voids and indings may have been con- expans~-n~-jnoints custom shapes | founded by exposure to asbestos Risk evaluation be widely used in metal molding and as furnace combustion floer inhistation studles Health effects Skin Irriterion and upper respiratory imitation are largely the same as those found with tirez glass service eflects RCF that has been in service 1 elevated there have noen for known trivesnga trivesnga 3 tons of the effects the high concentra- | alons of albome RCP have on s^'mals | in one Ad rats were exposed to RCF by nhalation for seven hourse day five days . week fo 32 week Fibers longer than | lazne 5 had levels of fice Animals . sacrificed er the end of the study had 16 1987. IARC designated designated PF a Group 28 possibly carcinogens K Fe mass On B basis or anemal styles IPCS evaluated RCF with oner MMVPs Crystalline sition in the brin or enstebatre has been a by IARC as 2A prozably carcinogen tu Normans MMVF repitiations temperatures greater than 1.800 will undergo pantal conversion conversion to ensto , intersuria intersuria lmosis in an average of % of f ^fite lung ares eight rats had pulmonary Although no US regulares parelmes exist for any fibers save asbestos there palit^' ^ form of crystalline sho"that CEN CAUSE SU^ ~OS~ K tumors of W thret were care~ NOMOSI Their ot also one perlioneal are multipic recomme idiation NIOSH NIOSH the Nation Instinue for Occupational Lpidemiologic surditThere we no published reports dealing metothelimeotothselios | in co^-as Johmeron work at Los | Alemos the wed no cancer and ittlepal- Saregy and Health commended a 3 fic or 3 ing guideline in 1977 1977 Fiber plass and minen wool manufac with the health experience of people | monary fibrosis in ar 30 hamsters turers recommend a staid of it it who work with k Trwo investiga { showed mesothell me burnofibrosis based on immutation The safety and Health nons one in Eumpe and the other in the United States 8.e st^,dying the health of workers engaged in the evans- The exposures were conducted at 200 | day week Gio six kolesa kolesa days a for 24 monitis One of 157 conpol animals Commince of the Bunding ar Topchen Depanmer of the AFL asso re ommends a standere of 13 13 Alli facture of RCF In October 1989 a pratimunary report from the Eumpean study of over 650 RC1splant RC1splant worken } unexposed to fiber di veloped & sponte- 1 TOS tumor in June 1988 to help cia some of USHA proposal is expected for fiber glass mineral wool and refractory ke- tamic fibers over the next year Recent was made availabir it noted that ne The uncertainties a wwwo year inhalation ! studies on animals may affect the risk eviden 'ewas found Ff preuobserody preuobserody preuobsrdy preuobserody in rask and hamsters was begin by i 3 Evaluation for RC Ps i t tS: PS aitRise 2S SS SER a SEBa0k7t ne24. aay te ihe sae: x. we ws 03/27/92 16:31 005 005005 rs Peers ey Control of levels of respirable particles or fibers is accomplished respirable respiabl combina- don ofengineering changes work addi- tices and protective equipment In tion regular medical surveillance of ex- posed populations is recommended SYNTHSYNTHETI ESYTNTIHTETIT FIBERS Arunid filter Aromatic polyamides constitute the aramid fibers which are durable and have high tensile strength These fibers generally fall outside the respirable range but certain of them have fibrils that may break off and become respi- rable It is not clear that fabrication gen erates either a fibrous or particulate respirable Only a single experimental study of chronic exposure to aramid fibers has been conducted Thin aramid fibers at a concentration of 100 oc produced fibrosis and specific tumors Shortterm inhalation studies suggest that respirable organic fibers do generate a tissue response in animals intraperitoneal injection studies have shown # slight increase in the Incidence of tumors and of fibrosis Exposures mea- sured at manufacturing locations indicate fiber levels ranging from undetect able to less than 1.0 cc Carbon fibers The term carbon fibers refteo rbosth carbon and graphite fibers They are synthetic fibers prepared by the hightemperature processing of polyacrylonine plich or rayon They are characterized by light weight high unsile strength and flexibility The aver- age diaom f te he t fibee r ir s 5 to 81 81 but up to 25 of the fibers are respi rable by humans There have been two short inhalation studies one subchronic term one chronic of carbon fibers Unfortunately the studios were conducted with materials that had large proportions of paniculate matter of fibers that were not respirable by rats Injection studies have not shown a significant increase in tumors but in vitro tests have shown both genotoxic and cytotoxic effects Dermal studies have not shown statistically significant increases in tumors There have been only limited stud ies of exposed populations and epidemiologic data is not available for risk assessment What data there is on re- spirable carbon in the occupa tional setting indicates only minimal exposure buvojefin finer The family of polyolefin fibers consists of polypropylene polyethylene and polycarbonate fibers The uses are in home furnishings such as rugs upholstery curtains and bedding These fibers are generally not respirable even though fine fibers are used for light- weight insulating clothing and for air Filtration There has been one subchronic inha- lation study with sized polypropylene fibers it showed biologic activity at 90 days but no fibrosis Variable low lev- els of toxicity were found with injection and in vitro studies No epidemiologic studies or data on workers to polyolefin fibers have been published SUMMARY This review of the scientific data shows that in terms of physiologic effects there are major differences from one made or natural fiber to the next Most of the data is reassuring but we do need to reduce levels of exposure and to detect disease at an early stage Personal risks and workplace protecprograms may become the subject of judicial or regulatory scrutiny In that context is worth noting that historically the recognition of occupational pulmonary disease has come only after the fact from the study of mortality pat- tems This retrospective approach is no longer moralloyr sociopolitically accept able This paper we hope will supply the perspective and scientific overview that will allow physicians to make informed Judgments about the risks cur- rently associated with made and mineral fibers i] Special thanks to Thomas W. Henerberg PhD Senior Toxicologist and Gerald R. Chase PhD Chief Epidemiologist of the Manville Technical Center Denver Colo Ther y ala so cd ontro ib- anted to this article Suggested Reading International Agency for Research on Canter IARC IARC Monographs on the Evaluation of Carcinogenic Risks to Hu- mans Made Mineral Fibres and Ra den Lyon France Vol 43 1988 International Programme on Chemical Safery IPC Made Mineral Fibres Environmental Health Criteria 77 World Health Organization Geneva Switzerland 1988 Bunn W Hesterberg T. Chase G et al made mineral fibers In Medical Taxi- cology of Hazardous Materials Sullivan J Kriegel G od Williams and Wilkins Bajtimore in press US Environmental Protection Agency USEPA Health Hazard Assessment of Nonasbestos Fibers Health and Enviroomental Review Division Office of Toxic Substances Washington DC 1988 VENA frrepresnsgsncteraeataln i alehiy MEDILEGAL BULLETIN RE - aummaainans te Regulation of the Manufacture and Use Of Potentially Hazardous Substances William B. Bunn MD JD MPH Senior Director Health Safety and Environment and Vice President Manville Sales Corporation Denver Colorado Jn the United States the evaluation and regulation of the health effects of commercial products is both intensive and comprehensive internationally scrutiny is increasing Before a new commercial product is introduced it undergoes several levels of review For pharmaceuticals pesticides and consumer products there are specific standards for full evaluation and regu- latory review appropriate testing is mandated before a new product can be approved For chemicals petroleum products and other new commercial introductions regulatory review is required by the Toxic Substances Control Act TSCA Regulatory suthorities may also require special studies of po- o tions Other states have implemented | sub their own regulations but most state and local regulations follow federal ever the implementtimae torieoxpno- sure limitations may be substantially dif ferent The US government mandates materials govthority during particular problems for erxepguolnaetrisonsanpdosmeultins- tional corporations The European Community has implemented regula tions similar to the comprehensive latory structure in the US Elsewhere in the world health standards are rap- idly expananddeivolnvigng In addition to this regulatfroarmeywork a second area of legal control is exercised through the tort system ^ ver the years case law has evolved a series olifabilities procednts that impose significant corporations and individu- nh that do not adequately test prod ucts assess risk communicate possible of to assume the safety of persons exposed maurer or user a product is so the product There is increasing roc- bea regulated The Hability in metrospective ogniofta i dutoy nnot onltyo inform Fh but to perform | and several die any and all parties am Nable a stewardship Strict stan of ld iabia lityrfordpots en- for insttio tinu stittue te effecIII | tive programs make this area of law potetno ta ipoatenltilalyly toxic substance ; | thedevel of o copmmmoe n n expt ectations and the increasien worker and consumer awareness will make the Environmental Presection EPA regulmes exposure of the gen- eral public ; 1990sa tremofetnredmeonduouss challenge for health professwiorokinnag wlitsh manufacturers warkers and consum- ers The combination of expanding The OS ofH OSA HA OSHA dimctives include communica tion general training and specified compolf icoampnlicane ce A permanent of functiOo SHn A is to assum adequate communofithecpoa tent tiai l haozan rds from the manufacturer of the product to the worker The Nazard Communi cation Standard mandates a written pro gram including the labelling of prod- ucts and work areas the preparatioonf Other venues In additiotno federallaw state and local mental exposures States have laws requiring special tabelling and impos- ing restrictions on release of substaners California for examaple has to Prepo- sition 65 and Toxic Hot Spots regule- sociopolitical concems and new tech- nologies and materials means the problems will increase not lessen Health professionals then must engage in risk evaluation and communication This with the recognition of the complexity and comprehensive nature of the regulations and includes a sensitivity and an oriented apprto obotah c workher and consumer protection e omnes r aceiine ianrormimniapar buee baryey - eee eee Xe amas MP 3.32.555.1212 Occupational Occupational Problems in Medical Practice in produced by MFI under special grant This publicmion mellech us opinioofntshe panici- Medical Publications LAG 3422 Oid Capitol Trall Wilmington DE 19808 paring authors and is not to be ascribed so she priblinker Current prescribing information should to consumed before an of y any product men- tiomed in this publicmion Copyrig'1h99t1 by MIF N^omaterimaaly be reprion wdholue ocr ie n padrt in any form withDin wrinan permission from the publisher Occupational Problems in Medical Pratice in a trademark of Medical PublicatioInncs. 30 996-3637 996-3637 vra vra lla.m. lla.m.