Document q3mQExBvxK53XrBJ3BYpx8dBE

( f t i ! ] 3l if PLAINTIFF'S EXHIBIT Friday November 4, 1983 Part VII Department of Labor Occupational Safety and Health Administration Occupational Exposure to Asbestos; Emergency Temporary Standard i ST 00!) 5 9 5 8 f I it f j ( 510R6 Federal Register / Vul 40. No. 215 / Friday. Novc.-bcr 4. H'it3 ! Rules and Regulations DEPART UCMT OP LABOR Occupational Safaty and Haaim Administration 29 CPR Part 1910 (Oochet Ho. N-0J30I Occupational Exposure to Asbcatoa aosmcy: Occupation Safaty and Health Administration |OSHAL Labor. action: Emarfancy tamporary standard. sueaeuurr. OSHA is issuing an emergency temporary standard (ETS) to reduce the parmisaibla exposure limit (PELI for asbaatoa from 2 fibers (longer than S micrometarsi per cubic centimeter (2 (Ice) as an etfhl-hour time* weighted avenge. to 09 f/cc During the period of the emergency standard, employers may uaa ail practicable control methods, such as engineering controls, work pracocas and personal protective equipment to meet the new limit of 09 libera par cubic centimeter (09 dec). Training programs are also required to be instituted within 30 days. The basis for this ETS is OSHA's determination that continued employee exposure to aebeetoe under current conditions that exceed 09 f/cc presents a grave danger of developing aabettoe- uiduced cancer and asbestosia to exposed employees, and that an emergency standard la necessary to protact thorn. The ETS amvus also aa a proposal to revtse the currant asbestos standard pursuant to section Rb| and 8(c) of the Act This coboa also requests comments on the appropriateness of including the provisions of the ETS as permanent revisions to the asbestos standard in addition. OSHA will soon publish a separata nodes of proposed rulemaking that further explains tha isauaa under consideration far-tee permanent standard and which ramaa soma additional issues regarding tha application of certain provisions of tha asbestos standard to tea coostraettoo industry. That nodes will Invtta public command and will achodaio o rulemaking hearing pursuant to Secdou 8(31 of the Act concerning the proposed permanent ravlaiao to tea asbaatoa standard ___ Dana: Tha effective data for this ETS ts November 4.190. Comments and evidenca concerning tha proposed revisions to tee permanent standard . made by tha CIS mast be received on or before |senary X1994. As noted OSHA will publish a node* of proposed rulemaking shortly that will set due data* for submissions to tha asbestos docket for tbs issues raised therein. aoonassiK Written comments should be submitted to the Docket Officer. Oocket No. H-03JC. Room S-8212. U S apartment of Labor. Third Straet and Constitution Avenue. N.W, Washington. D.C. 20210. son suutmm nwonasaTiON contact: lamas F. Foster. Director. Office of Information and Consumer Affairs. OSHA. U9. Department of Labor. Room N-3837. 200 Constitution Avenue. NW. Washington. DC 2021& Telephone (2021 323-S1S1. lUMiiiegwTAnv noonuanon Table ef CooHeta I. Incraducnoa U. Legal Authority end Background Ul. OSHA Rationale for the ETS A Crave Danger B. Need for aa ETS Supporting Docammtauoat IV. Occupauooei Haalth Data V. Quantitative Risk Analyaw VL Technical and Economic Feasibility A Taduncal Faeaibility B. Economic Feasibility VIL Emnrannwntal Unpaid. Ragulatory Flexibility, and Regulatory Aaalywa VUL Summery and ExpUnanoo ef the CIS IX. Public Partiopatloo. Authonty tad Signalers. and Peri lflO (Amended) L lafrothirdon This is an emergency temporary standard (ETS) issued pursuant to aoedon 8(c| of tha Occupational Safety and Honlte Act of 1970 (tha Act) (M Slat iSOfe 29 UAC S8SL tea Constraction Safaty Act (Pub. L. 91-94: 40 U9X. 333). tec Longshoreman * and Harbor Workers Compensation Act (33 UJLC 941L tee Secretary of Labor's Order No. 9-B3 (4S FR137381. aad 29 CFR Part 1911. This ematgancy standard consists of revisions to tea existing standard covering occupational exposure to asbestos. 29 CFR 1910.1001. in order to protect employees from a grave danger from continued exposure to asbcatoa at current exposure levels. OSHA has determined that workers axpciod to asbestos under exposure condition! existing under tea currant standard fact a grave danger of developing incurable cancer and' asbestoets. Further. OSHA has found that an immediate reduction in exposure levels to 09 f/cc or below is necessary to protect such employres from tela grave danger. Therefore OSKA Is issuing this ETS to compel reduced exposures to respend to tela emergency situation. OSKA's determination teat a grave danger currently exists is predicated upon quantitative risk estimates in this record * hich point to a large number of excess deaths from cancar (and x*!i<*stoii| among currently exposes workers which era attributable to continued exposure* under prasent working conditions. OSHA estimated the number of cancer deaths svoidad through lowering of Iho exposure to 09 f/cc based on 6 montea. l-y*ar. 20-year and 43-year periods of exposures at current levels.* The predicted cancer deaths avoided that result from these periods of exposure are respectively 210. 429. 3723 end 7S1S. A more detailed discussion of these estimate* is found in tee sections. Quantitative Risk Analyst* (Section V). Crave Danger (Section 111 A|. and Need for an ETS (Section ill B). Risk* of this magnitude at pemuttid and actual exposure levels defined * situation which demanded immediate ragulatory action. Evaluation of the relevant scientific data, policy considerations and exposure patterns of workers has convinced OSHA test continued exposure at tea current PO. end under actual workplace conditions constitutes a "grave danger- to employees, and that an ETS is needed to protect them. The ETS require* teat employees may not be exposed to concentrations of asbestos exceeding 09 f/cc on an 8-hour time-weighed average beau, and permits tea employer to choote among engineering controls, work practice* and respirators to reduce rxposurva to tea new PE,. However, tea requirement in | lBiatOOlfc) to utiliM feasible engineering controls and work practices to reduce exposure levels to 2 f/cc remains in effect under t_i* temporary standard. Tha ETS also requires employers to institute a training program within thirty day* of tea affective dsts of this emergency standard. The trauung progam will include instruction on respirator fitting and use. handling of asbestos, medical Information, tha relationship between smoking and lung cancar. and a review of tea asbestos standard. The ETS applies to all Industries cowered by tee Act including "general industry*, construction and maritime Industries. . oai bow UCi tt idutnel aaaOe mi OSHA esactaOaa Oai saew as aaO as CIS le aseeaaary ewa il OSHA lull amdaaiaeiy * --* unit Henvnr ns Aesacy Mime it a tsrraeruw m cstaisis heiMiiu Senwin h*ei ITS <nin| Iif*ism mil best X ui S r**n el mnui to L at AS tl* seteWiehaS br Oe CIS. Alihew* Os CIS eipme anOta * names. facm act neeim Oai niaukiea m a inniti vWM Oet he eeewiewe miOo t aaaOa. as itiai ihan wUi he ee far m pralartiae tar ampeaae aneiarwe. le OSHA a axgarenee aa* indfuel. ceaifira* -. -X hia amwery Suecnaa tee caeieHnas fwarak.ae <er a peraaaaeai auadare mmSis * raarie aI aa CTS hea aa* cee ha Sena. ST 0 0 i) 5 9 5 9 Federal Register / Vul. 43. No. 215 / Friday. November 4. 1963 / Rules and Regulation* 31087 As provided in 29 CFR 1933.22. the 24 II. Legal Authority ami Background Slates with their own OSHA-unproved occupation*! safety and health plans are expected to adopt a comparable .4. Lryal Authority Section Sfc) of th* Act provides for standard within 30 day* of this immediately effective emergency publication date. These Slates are: temporary standards in cartain Alaska. Arizona. California. Connecticut circumstances. Th* Secretary hat the (for State and local government employees only). Hawaii Indiana. Iowa. Kentucky. Maryland. Michigan. Minnesota. Nevada. New Mexico. North Carolina. Oregon. Puerto Rico. South Carolina. Tennessee. Utah. Vermont Virginia. Virgin Islands. Washington, and Wyoming Also, in response to the emergency , conditions faced by exposed workers. OSHA is stepping up its enforcement activities in targeting workplaces where asbestos is handled. ' The temporary provisions that are being added to the existing asbestos authority to issue tech a standard, without rulemaking. *1/ he determine* (A) that employees are exposed to grave danger from exposure to substances or agents determined to be toxic or physically harmful or from new hazard*, and (B) that such emergency standard is necessary to protect employees from such danger." 29 UAC SSSlcHU Thus, th* danger must be "from" worker exposure and it must be "grave." not merely significant and the regulation must be "necessary" to address "such danger." not merely reasonably necessary or appropnat* to previda nf* employment. In addition, as in stcuon standard prescribes the maior Sfb) permanent standards. OSHA may component* of an occupational safety impoaa requirements in tha emerysney and health standard. In general, most of standard only to the extant that they at* the currant requirements remain "faaaibla" within th* meaning of section unaffected by the emergency temporary 6(b)(3) of th* Act standard. However, compliance with The Fifth Circuit has amphasizad tbe soma requirements will be triggered by important* of tha severity of health the new exposure limit of OJf/cc n. effect* in OSHA's considmatfao of instead of die former PEL of 2 f/cc. For \ whether an ETC is appropriate: example, requirements such as change i\ the dsnge* of incurable, permanent, Jrooms remain unaffected by the ETS i or fatal ceaeequanees lo workers, as o**osd and the trigger level for change teems easily canUs sad flaeung effects so their remains the former HL of 2 f/cc / 1~~i"h tiiirmn iiupmset si ihi (I !9iaian(dX4}). However, the ETS caaaidamuaa af th* asesssMy far rmeigssry ifrequire* that whan concentrations may exceed the new PEL the employer must poet signs indicating such locations amuse is mast s yiw Sinew ' fhndo Nad Gnawers Sesocwcin Ine. v. Untmb S'tem'flaperiniii at tabor. SSS Tib. 122 (CAS). If inaiOOHkXfl). OSHA based its decision* concantmg appropriate provisions for the ETC on its determine tion* of the kind and degree of protective action needed to protect against a grave danger and the feasibility of instituting that* provisions OSHA also ha* mtsrpntsd relevant judicial decisions to require that Its evaluation of tha gravity of tha dangar and lb* nscaaaity for amcrgancy action must be mad* in th* context of actual workplaca conditions. during the period of the ETC. Under section 4(b) of the AsL OSHA will shortly schedule an informal rulemaking bearing on the proposed permanent changes to the standard. OSHA will alee propaee ether revisions to the asbestos standard that will be explained in the separate nedae af proposed rulemaking. Application of certain proviaiaoa of tha aabeaten standara to the construction industry will bo raised at that tima. OSHA anticipate* that thia notier will be t. Events Loading to the ETS In |una. 1963. OSHA ncanred a pabtion for an ETC boas th* International Association of Machinists and Aaroapac* Workars [Exa. S4-2M). Subaaquantly lattars supporting this petition were received from it other unions (Ex. 64-264 to 142M. 64-3V lo 64-391). The petition requested an ETS to reduce the PEL in 0.1 f/cc. to modify some existing work practice requirements, and to require other protective provision* regardless of publishsd shortly. OSHA is now accepting written comments on thoa* issues raised la the ETC which tr* relevant to revising the permanrnt rule. exposure level. The mam reasons set forth in th* petition and supporting latter* era that continued exposure jnder eurreni workplaca coiidit.ona The S-cretary must promulg its s constitutes a grave dangar and that section ii|b| standard no Inter th in six Jul.iun* rjnedul action until a months jf'.cr publication nf the smergt-ncy suncartl permanent standard is promuigatad wnu-d cost large numbers of currently- exposed workers thrir lives. OSHA ihjrcs ihe genuine concern expressed by the petition and letters from unions representing thousands of tmplovses who art directly faced with th* threat of asbestos-related disease from continued exposure. And OSHA concludes that faiiura to issue this ETS may cost a number of exposed workars their live*. In August 1983. OSHA completed comprehensive risk assessment based on numerous human studies which sstimatsd th* number of sxcess deaths from the throe major asbestos-related cancers, i-*_ lung cancer, mesothelioma and gastrointestinal cancer, at tha current permissible exposure level of 2 f/cc and at various reduced sxposur* levels. OSHA placed this document. "Quantitative Risk Assessment for Asbestos-Related Cancan', in tha Asbestos docket in August 3903 (Ex. 64- 349k OSHA subaaquantly revised this document (See Ex. 94-392). 2. Hittoty of the Asbestos Standard. OSHA has regulated asbestos one* iffl A 12 f/oc limit for asbestos wa* included io tha initial promulgation of OSHA standards pursuant to section C/1 3(a) of tha Act, on May 29.1971 [38 FR 10*68). la rasponaa to a petition by tba Industrial Union Department of tha AFL-QO. OSHA issued an ETS on CD CD asbestos on December 7.1971. which established a PEL of 3 f/cc on s timeweighted average basts and peak cn CD exposures af 10 f/cc. CD Th* currant standard, promulgated in )una 1972. first established an 8-hour time-weighted average PEL of 3 f/cc and t ceiling limit of to f/cc. The limits were intended primarily to protect employee* (gainst. iibestoeta. end it wet hoped that they would provide some incidental degree of proteedon against cancer. Effective |uly 1979. tha TWA limit was rsducad by tha standard to 2 flee. This limit has remained in effect since that time. Th# standard also includes provision* covering methods of compliance, monitoring, medical surveillance and housekeeping. Court review of this standard upheld ill major provisions, but remanded two issue* far OSHA's reconsideration. tUD v. Hodgtan. 89 P. 2d 467 (CADC 1974|. These issues wan whether the (uly 1976 date fat the 2 f/ec standard should b* sccelantod for sonw industries and the adequacy of tha 1 year retention period far exposure moditaring records. Subsequently. OSHA increased this retention period to 20 yetr* (41FR 11304) and tho acceleration issue berume moot. After reviewing th* then tvai'abla scientific data, in October 1875 OSHA published a nodes of proposed a ( 1 1 1 / i % 5! ii 11 ( 330M Federal Register / Vol. 48. No. 21S / K-:du>. Nuw~t:: 4. '.9&1 / Rule* and Regulations ruler.emg to feme the etbrito* <und..rd bccjjc OSHA believed that lulF- ini medicul and scientific ewdentc Had been accumulated to vacant (ha designation of aabeatoa aa a human carcinogen" and that advances >n momtonnt and protecuva technology madt reexamination of (ho standard desirable." This proposal would hava reduced tha time-weighted avarago to O S f/cc and imposed a ceding limit of S f/cc for IS minutes (40 FR 47492k The basis for tha It'S proposal's rrduerd parmissiHs lava! of 0.5 f/cc was OSHA s than current policy for carcinogens that no safe threshold level was demonstrable and. therefore, tha Act required OSHA to sal (ha PEL as low aa iechnologically snd economically reatibla. This policy was raiacled by the Supreme Court in the benzana decision i/lv it. api. sat u s. an (i9aoi). osha limitad the proposed revisions in tha 197! notice to all industries accept construction. No heannt was scheduled on the 1979 proposal. Also, slthoufh OSHA announced its intention to develop a separate proposed ranstoo applicable to the construction industry, no such proposal has been published to date. OSHA it basing ns present deaaioa to issue an ETS. end to propose nmsiona to tha permanent standard covering all employe**. on information and analyses which postdate the 1979 proposal. Therefore, tide ETS marks a nose regulatory initiative, related to. bet not pen of tho 1979 proceeding On May 24. 1993. OSHA coiifuited the Construction Advisory Coalmines far Occupational Safen and health (CACOSH) concernmg applicability of a new asbastni standard fee the eoniiroctioa industry. CACOSH endorsed OSHA'I position that changes ic tha PEL made for general industry should also apply to tha construction industry. OSHA is alas including tha comments sad data racaived in rosnonaa ta tha 1179 notion in tht record of this procaadlng. with tho jodtmandiag that team cotnanantars may hava changed inatr poaitiona based on intervening scientific development* and policy shifts. ___ In the decision lo iik as ETS tha Agency net rerewee this regulatory hiatorv of eetes'.os. However, the Agency `lasoa the decision to issue aa ETS <n 'hr aetu.il emergency conditions which njw ccnf.'.mt inposed workers, on epi Ivmoligic stud'et hat provide data to ru*a nu.mer.cal estimslea of risks an.l cn in'eyiretauons of those studies using quantitative risk analysis. 3. Thf R ..V.ncAi.-g to flev.w tht Ptrr-.z.:ca S,'.' :.-J. The S(b| rulert-Aing inmuird by this proposal is intended to be '.iir.r.ed to the revisions mede by the ETS and the additional proposed amendments raised in the nonce of proposed rulemaking io be published soon. The maior subieeta of the a<b| rulemaking wi" br reducing the permissible exposure limit, revising the definition* of asbestos end asbestos fibers, reassessing the method* of comptiaace to achieve such limits, revising the provision* regarding respirator selection, revising the sampling ind'Snalyocai method to improve reliability, and adding a training requirement. OSHA will also raise issues regarding the application of the permanent standard to tha construction industry. As previously staled. OSHA will toon publish a separate nonce of proposed rulemaking to further explain these issues. III. OSHA's Rationale for tho ETS OSHA has dcu'rmmed that prevailing conditions avalving worker exposure to airborne asbestos dust justify the promulgation of an emergency temporary standard. OSHA estimetea that approximately 375.000 worker* are exposed to asbestos at venous levels (Table Ik ranging from * high value of 20 f/ec to below 09 f/cc. OSHA hat estimated that under current exposure conditions eebostoa-oxpoeed workers face an extraordinarily high risk of contracting eeboetna related expose whether tha risk la compulad overt working lifattan of axpoeera or for exposure periods aa short as 8 month* Tho average excess cancer risks for all workers exposed above U f/cc using available exposure data and reiying'oB the ntk assessment are estimated at approximately 198 excess cancer deaths per 1000 workers for 49 year* of J exposure. 139 deaths per 1000 workers ' (or 20 years. 10 per 1000 workers for 1 year, and 8 par 1000 worker* for 9 months of exposure. OSHA believe* that risks of these magnitudes, taking Into account all relevant considerations such as total nuaosn of workan at risk and quality of supporting data, cotuotuta aa emergency einiatma which require* immediate response by the agency. The Act stales that when certain statutory criteria art met OSHA it authonaad to respond to ac emergency situation by issuing *n ETS. Tha two pronged statutory test (or ar. ETS i* 'hat (1) employee* met: be exposed to a grave danger firm exposure to substsneas or sponta determined to oe toxic or physt-tally harmful, and that (2) an emergency standard la necessary to protect emoluyee* (rum such danger*. After c.alusting all tha evidence uiuilubl* tj the agency concerning tn* 'evenly and magrr.Lit of the nek of aibcsios-rvieted disease to the current asbestos-exposed working population, comparing these risk* to other occupational risks, applying relevant policy considerations, snd reviewing ell relevant luditsl decisions for guidance, the agency has determined that both prongs of the statutoqr tcel art met and that an ETS should b* promulgated. For purpoeee of clarity, the discussion is divided into two parts. "Crave Danger ' and "The Need for an ETS." OSHA believes, however, the I the factors which indicate that a substance constitute* a grave danger are related to and overlap those which determine that *n ETS is necessary. A. Grort Donptr OSHA has determined that tha risk to workers from exposures to asbestos et conditions that exist in the workplace pose e grave danger of death from cancer and of severe disability from the lung disease, eibestosis. In making a "grave deafer* determination, the seventy of tht disease produced by exposure to the regulated substance end the magnitude of the predicttd risks of disease must be considered. In addition, the Supreme Court ha* suggested that a determination of "grave danger* indicates a situation, where the risk it more than 'significant* [IUD v. API. tupmo. 3k OSHA ha* applied that analytic approach endorsed by the Supreme Court for "significant rtak* detertcinsnon* in evaluating tha gravity of the danger faced by asfaestoe-exposed workers. The Supreme Court gave some general guidance s* to the process to be followed It recognised that while the Agency mull support its finding that e certain level of risk exists with suostantial evidence it tlso recognized that its determination that e particular level of risk is "significant" will be based largely on policy consideration* [IUD v. API. 44* U.S. 459. Ud n. 42). OSHA believes, therefor*, that its daterminsuons regarding tha magnuude of the ntk faced by employees should to the extant pouibla. rely on quantitative expressions of that risk, utilising tha best available data. Tie Court stated lhat the significant risk licitrmination required by the OSH Act is "not a mathematical siranjackel." and "OSHA is not required tn support iis finding that t significant rsk exists witn anything approaching scientific certainty. "'A rtviawtng court [is| to give OSHA sema leeway where it* findings must be mads on trie frontiers of scur.tific knowledge |jnd that) "" the Agency is free to use consenutive tsump'icrs ;n .merpreting the data 9 GS0 0 0 1 S .I 1 federal Register / Vol. 4. No. 2IS / Friday. Now-iiior 4. 1383 / Ruies and Regulations 51089 with respect la carcinogen*, ruling error on ihc tide of ovcrprufcctton ruhrr than undcrprotection" |468 US 41 035. CSO|. In th* cat* of asbestos. th* data available art of unutuai breadth and high quality. Hourbyar. because nab aneiiment itaolf Involve* many uncertainties. OSHA mad* cartaln assumption* in It* analyst* and tvaluation of these data. In assessing th* risk for asbestos-exposed workers, OSHA has attempted to use realistic assumption*, although th* court stated that th* Agency we* free to usa "conservative assumptions" in t.i'.crpreting data. OS11A. in many cases, has indicated where different assumptions may produce different results. In addition OSHA cautions that because th* risk figures finally derived are th* products ofa process which, as th* Supreme Court acknowledged, la "on the frontiers of scene*." they should be viewed a* approximations of the degree of risk faced by asbestos-exposed workers and sot as precise ftxad predictions of the number of workers who will actually develop disease. OSHA has evaluated to* kinds of dangers presented by~asb*staa exposure, th* quantification of those dangers under present asbestos exposure conditions, the quality of th* dais on which risk asttmat** are based, a companion of aibestoa risk* to other occupational rt*ks. and relevant policy and legal considerations in concluding that workan are exposed to a grave danger from aibestoa. 1. .Vorure of th* Diseases. As stated sbove. the nature of the disease associated with exposure to * toxic lubstance is one of th* most important elements OSHA evaluates in determining whether a grave danger exists. This factor waa discussed in Honda Ptaeft Grower* Astociaa'an. lee. v United Stores Department ofLabor, supra. The court, in overruling OSHA'e nrganophosphet# pesticide ET3. observed: We retea eey mapwMan that Seethe Met occur before health and eefety standards awy be sdopted. Nevanhaiaea.ihe^an*ref to mim ae oppeeed a* eoatfy tumble aad fltt-nt tfftttttb*r hsoitk. benomas i.itponatt in tht torn(deration el dte rtettstty tor emeiyaney mtotum te uavr e grow dottfvr. HI F 2nd el 112 (cmphoeis udaedl OSHA is ewer* of no instanced In which exposure to a toxic substance ha* more deariy demonstrated detrimental health effect* on humans than hat nstestos exposure. Th* din-aavt caused by itdcs.oi exposuns are in Urge pan life-threatening oc disabling. Among these diseases are lung cancer, cancer of levels which workers currently fjee. the mesothelial lining of the pleura and Moil of the result* of these calculation peritoneum, end esbestosis. in addition, for cancer ere presented in Table 11 in workers exposed to eebesto* are et the risk assessment section of this increased nsk of gastrointestinal cancer, document. as shown by epidemiologic studies. Th* table set* forth predicted excess Although cole--vet*J cancer may be lifetime cancer risks for exposui*. uf curable if detected in an tariy stag*, on* year. 20 yean end 43 years. Risks other gastrointestinal cancer* are usually fatsL OSHA also believes that asbestos might indue* cancers at other sites, which are also often fatal. Of these, lung cancar constitutes th* greatest health risk for American asbestos workers end he* accounted far more than half of excess mortality in some occupational cohorts. About 904 of lung cancar patients dia within 9 years of diagnosis. Mesothelioma i* an incurable cancer which i* usually fatal within a year after diagnoeia. It is epidemioiogically linked to asbettos exposure, and occurs very rarely, if el *11 in persons never exposed to asbestos. Aabestosis. a type of pulmonary fibrosis, is usually nonreversible, its advanced itapes are disabling, aad can be fatal. OSHA conduda* that ill (has* diseases ire very serious, end that tha axes** mortality from such levers diseases tmiat be considered an important factor for making a grave danger determination. 2. Degree of Risk of Developing Dangerous Disease. OSHA baaed its calculations of extant of risk faced by worker* under current exposure conditions primarily on the results of * quantitative analysis which derived numerical estimate* of cancer risk at various cumulative exposure* corresponding to levels at which workers are exposed (Ex. 54-392). Although 2 f/ce is the current PEL for tsbeeto* exposure, actual exposure conditions very widely, mostly by Industry segment. As explained later in this document snd aa sal forth la Table L avenge ambient exposure levels la various industries include high exposure levels such ti 20 f/cc in crywall removal, renovation and demolition: g f/cc in shipbuilding snd repair aid- rang* exposure levels such as 2 f/ce la secondary febneating of cement (beet, packing and gaskets and paper product* for exposures of 6 months are dosaly approximated by one-half th* risk* for' exposures of on* year. Although avers;* exposures tn demolition end renovation are estimated st 20 f/cc th* table presents risk* only for selected exposure levels up to 10 f/cc These calculations show that the risks of asbestos-related disease are alarmingly high st current occupational exposure level*. For exsmpls. an estimated total cancer nsk of US excess deaths per 1000 workers exists for workers exposed for a 4S-year lifetime at 10 f/cc e level which currently exists on same construction sites. At S f/cc the exposure levels which ere considered evereg* in shipbuilding end repair, the nsk of developing siboftot-reiated cancer for 45-yeer expoaur* period is 149 excess daaths per 1000 workers. At th* current peraissibta level of 2 f/cc oo which also rtpresents ictus! exposure __ | level* in such industries as secondary _ fabricating of eamant (hast packing gaskets and paper products and 3 lebuildlng and refadng brakes, nsk u ' estimated ss 64 excess cancer detths per 1000 worker* for a 45-year expoeure c.-> period. cd Thee* risks remain very high when r-j tbe period of exposure for which, calculations are done is shortened to 33 years, which OSHA believes is another appropriate point for examination. The period of 20 years ia the approximate midpoint between 1 year end 43 years of exposure: also many workan receive 20 yean of exposure. Counterpart nsk calculations using 120-year exposure period are: for workan exposed to 10 f/ gc. 140 excess cancer deaths per 1000 weaken; for exposure* to S f/cc. 105 excess cancer detths per 1000 worken end for exposure* to 2 f/cc. 44 excess cancer deathe par 1000 workers. OSHA also estimated risks of developing renear for a os* year period aad rebuilding end refacing brakes; LI of expoeure at various levels to which f/cc for dry processing of textile*: sad employees an exposed. The counterpart lower exposure levels such as OS f/ce risks for exposures to 10 f/cc for one and 0.2 f/ce in th* manufacture of floor veer ate: 131scats cancar deaths per tile. 1000 workers; to 9 f/cc. 1 excess cancar Because OSHA is required to constdor deaths per 1000 workan and to 2 f/cc. 3 the actual danger faced by workers is excess cancer deaths per 1000 workers. assessing whether exposure to a Even ai current workplace exposure substance presents a "grave danger". levels which are leu thin th* current OSHA looked at th* risk of developing PEL sx-jsordinsrily high risk* of disease not only it tha 2 f/cc disease exist At 0J f/ee. 17 excess permissible level but et ell exposure cancer death* per 1000 worken an 51090 Federal Remitter / Vol. 48. No. 215 / Friday. November 4. 19U / Rule* and Rcgulat:i>ns prediclcd for 43-year lifetime exposure, end 11 excess cancer deaths per 1000 workers for a 20-year exposure period. OSHA notes that the above calcuiaUona are for cancer risk only, la addition, asbestos-exposed workers face a high ntk of developing aabeatosia. a disabling and often fatal disease. Prediction* concerning the estimated magnitude of the asbeatoau nsk have been performed by OSHA and are discussed in the risk assessment section of this document. Accordingly. OSHA estimates that at 2 f/cc. SO worker* per 1000 exposed to asbestos for 4S year* will develop disabling asbastosis. At 05 f/cc for 43 years, it is esumated that 12 worker* par 1000 will develop disabling asbestosi*. Aabeatosia nska can also be estimated for exposures for durations shorter than 45 years. For example, the risk of disabling asbestoais from exposure to 1JO flee for ZU years ia 12 cases per 1000 worker*. OSHA'e estimates of the magnitude of the eibestoeie risk are besed oo found data from good epidemiological studies. OSHA balirves. however, that the confidence which can be placed In predictions of aibestosi* ntk it not as grist st for the predictions of caocar nsk. This is bocautt tha cancer risk titimaits are based on a larger and more vanad data base and are denvwd from dose-extrapolabon ssadals that are better established Because OSHA has determined that tha hake for cancer lone indicate a grave danger. Ida additional risks of davtloping ssheslosia are not norasaary to iuadfy this ET1 Howtvtr. OSHA has oeosidtrod that the additional and independent risk of developing asbesiotta increases tha danger faced by exposod worker* and underscores the gravity of tha health threats to smployset posed by asbestos 3. Quality of Data os Which Atab Stunwta ore SosedTha uadariytag data upon which tha quantitative nsk assessments for esbootos are bated are high quality epidesuoio^s studies, conductsd in occupational envminmantt. OSHA tmphaaaaa that ha da'* bases for ssbsotos sie of unusual quality end tins Unlike moot potential occupational nmnngma asbestos has best! studisd oftaa and horougnij for evaluation of its tfTscia on occupational populations. In aenv.ng that* quantitative estioaiM far cancar risk. OSHA utilised eleven studies for the caiculetion of the lung cancer risk, four of which were also used to calculate the mesothelioma risk. Investigation* involved "cohort" studio* where the frequences of various typo* of cancer* in workers exposed lo asbestos were compered to those in hazard. where the data are considered "control" groups not exposed lo both evaiiabte end reliable. asbestos or to those oi general The risk of excess mortality emms'-i population* such es U.S. males. Studies es * result of exposure to asbestos si me of such design are able to provide direct conditions in tho workplace today estimate* of txcesa nsk. eppaen to bo substantially higher then The studio* used by OSHA in deriving other risks experienced by worker* from doer rsspoors relationships for it* risk occupational injury hazards. Tb* assessment covered a vinery of work National Safety Council (NSC) ho* sitoeturns and Industrial processes. This reported the annual death rata* in 19*1 variety improves the predictive value of from work accidents in a variety of the risk assessment because it lessen* industries (Ex. 64-339). Using Ih* NSC or eliminates tha possibility that the date OSHA has reviewed the annual results ware unique to any on* mortality fawn work accidents par 1000 occupational situation or were in fact worker* in several industries in light of aberrational. Tha occupational settings the excess cancer mortality from a studied wera: worker* exposed at a single year of exposure to asbestos per chrysaiile textile plant from 1930-1*75 1000 workers. For example, in the high (Dement *r aL Ext. *4-03* and *4-037); risk occupations of agriculture end Canadian svorktrs at aa asbestas- mining-quarrying the annual mortality cement facility (FInkalsiain Ex. *4-240): rata* from work accident* were 0.34 end Italian chrysolite ainan and milters 05* par 1000 workers respectively in who worked during 1930-19M [Rubtno 19*1 (Ex. *4-130). In contrast, the death ti oi. Ex. *4-M|: workers in an asbestos rat* from work acddents for ell cement ptpe plant (Weill e< e/ Ex. *4- industries combined was 0.12 par 1000 200): workers In an asbestos production workers in 1901. plant and asbestos cement pip* factory OSHA ha* estimated that tha lifetime (Hondoreon and Entarime Ex. 84-44): risk for nu year of exposure to 2 f/cc of British workers manufacturing etbetio* asbestos is about 1 exeat* cancar deaths taxtila products (Peto Ex. *4-1*0): par 1000axpoaad worker* during the. asbestos miners and miOsn in Quebec. remainder of the workers' lifetime* (Ex. Canada (IJddafi at al. Ex. 84-Wh and tn 4-340). Thus, asbestos workers' nsk of tha Thetford Minas. Canada (Nlchoteoo excess cancar mortality from a tingle */ al. Ex. *4-72): and worker* year of axpootsro to 2 f/cc is roughly S manufacturing asbestos friction ' times higher than tha risk of accidental materials (Barry and Nawhous* Ex. sa occupational fatalittee bom on* year al nk employment in agriculture and mitung- "Wafl-condactad apidaaiologic '"quairytng. tudiaa that show a positive association Aa shown in Table 1. OSHA estimates between aa agent and a diaaasa an that many workers ara exposed to accepted aa tha most convincing ebostoa in tho vicinity of 2 f/cc. In evidence about human ntk* (Xtek addition. OSHA calculated the avenge Assessment in tha Federal Covammaac excess cancar nsk to workan exposed Managing the Process. National et condition* that exist in th* workplace Research Council 19*3. p. 21. Ex. Sa today (for those above 05 f/cc end using mi No extrapolation from animal data to tho scenario desaibod in Tabte 31 OSHA estimate* that 10 excess cancar human data ia necessary in order to -*--** will occur pur 1G00 workan (or 1 show carcinogenicity of tibestoa. For your exposure: thus th* average nsk to moot substances. OSHA must inter workan (exposed above 05 f/cc) in (he humac health effaerx. ruch as workpiece today ie approximately 20 cardaoganidty. from animal data. times tha "-1 fatal scadent rate* in Tha results of this nsk iimminl agriculture and mining-qaarrying purfoemad by OSHA agree wail with These comparisons are striking. They othar rocant risk assessments perfocmed shew that tha estimated risk of dying of by othar governmental and outside cancar from asbestos axposun at levels ectenttete (see Acbason and Cardnar) existing at tha workplace today far (Ex. *4-0* and *4-242); EPA fEx. *4- exceeds th* accidental death rat* in the 1*C): Kxcg and Chu (Ex. *4-001): Salikoff riskiest of industries. Although tbs era/. (*4-002); and CHAP (Ex. *4-25*1 estimated mortality rates for cancer due . Compiratim Analytic Insight into to asbestos exposure ara not completely tha magnitude of 'ha ntk associated comparable to tho total actual with asbestos exposure can he gained accidental fatabties, lb* review is by reviewing other occupational risks. cteariy useful in shewing that tha OSHA JUlisves it Is instructive to magnitude of tho asbestos risk it grav*. compare asbestos nsks with otb Ona example of predicted cancar risk workpiece hasards agreed on *a aa a result of occupational exposure is presenting an unusually high degree of ih* following cancar risk estimated from 'STOOD59G3 Federal fogistef / Vol. 41 No. 215 / F:-:iji November 4. TCB3 / Rules and Regulations 51091 s T l) U:J b *Jb 4 occupational exposure to ionising radiation. The estimated excels cancer fatality rate from *7 yeers of exposure t the maximum permissible occupational exposure to lomzuif radlatioo IS remsl is 17 to 29 per 1000 workers (Committee on the Biological Effects of lonitiat Radiation (BEOt) IQ predictions, see 45 FR18021. However, most radlatioo standards (unlike OSHA standards) require that exposure limits be reduced to the lowest level reasonably achievable below the exposure limit (the ALARA principle). Approximately 85 percent of radiation workers have exposures lese than one-tenth the maximum permitted limit The excess cancer deaths at one-tenth the permitted level ere 1.7 to 23 per 1000 worker* exposed 47 yean. Asbestos exposures of 45 year* to 2 f/cc are predicted by OSHA to resell in 54 excess cancer deaths per 1000 workers beginning work st eg* 25 (Ex. 54-382). OSHA's calculation for the overage excess cancer risk to worker exposed at conditions that exist in the workplace today (for (hoe* above03 f/cc) for 145- year exposure, i* 195 excess cancer deaths per 1000 worfcara. This figure was calculated by taking the number of cancer deaths estimated from exposure io existing conditions for 45 years for those workers txposad to gras tor than 03 f/cc of aabeetoe and dividing by the number of worfcara txposad to asbestos greater than 03 f/cc (multiplied by 1000). Therefore, the excess cancar risk st 2 f/cc for asbestos worktra is estimated si more than twice as high at the maximum permitted radiation cancer nsk and about 25 braes higher then the estimated cancer nsk of 95 parent of ihe workers txposad to radiation. At existing conditions, asbestos workers' exetss cancer riska ere estimated to bo S3 times higher than the cancar nsk faced by 95 percent of the worker* exposed to radiaboo. The rtok of asbestosit further inrrooooo dm significance of the riak from asbestos exposure. At 03 f/cc. OSHA eattoMtoa that IT excess cancer death* wtll occur us 1000 workers exposed 45 ysun. This risk i* approximately 7 times higher than tha cancar risk faced by 3! percent of the workers exposed to radiation. OSHA finds that these comparative ntke stronqiy support OSHA's findng that women exposed to air concentrations above 03 f/cc an (ar above the paint of significant risk and era at gravt danger cf dying from cancar. 3. Co.u !tision. OSHA's finding of "gra .* danger'' is based an evidentiary sr.it policy considerations. OSilA's determination that the magnitude of the estimated risk 10 exposed workers is alarmingly high constitutes the maior component of the "grave danger* finding The overall extraordinary degrao of risk, the extent that very high risk is found in many aibesto* using industries, and the unusually high quality of the dam utilised to make these assessment* present e very strong evidontitry basis fora "gravedanger" finding fust a* importantly, the unique gravity of asbestos-caused diseases, in . particular cancer, such a* mesothelioma which is linked almost exclusively to stboetoo exposure, strongly supports OSHA's finding of gravo danger. Also OSHA's comparison of tht risk of asbestos-related discern to other industrial risks underscores din extraordinarily high riek estimated for teboetoo exposure. OSHA has aleo noted the concern* of murkera about currant workplace conditions and the numaroue petitions for an ETS from unions roprasendng many exposed worfcara. Finally OSHA has relied on its experience in evaluating end raguiahng workplace hazards in recognizing tha extraordinary degree of risk currently faced by ssbootoo worker* and bi determining that such risk constitutes a grave danger to those workers. B. Wood for on ETS OSHA ha* datarmined that this ETS is necessary to protact employee* from grave danger, tha second prong of the Act's test'qf OSHA's oxarciaa of it* ETS authority (Section ofc) of the Act). As explained in detail, tha effect of this ETS is to save many lives whisk would otherwise bo loot to asbestos-related disease if currant working conditions were not changed. OSHA believes that employee* can bo adequately protected against this grave danger only by issuing an ETS. This is because no other Agency action and no other foreseesbis event would result in sufficiently reduced tsbettot exposures that would alleviate tha grave danger. Further, tha provisions of the ETS are tailored to effect tha necessary exposure reductions expeditiously. 1. Live* Savtd by frmiuig ar. ETS OSHA has estimated tha cumber of deetha avoided as a mult uf an ETS which would reduce the PEL to 33 f/cc (see Tablet 2 and 3). For cancer only, based on continuing exposures under currently existing conditions for g months, the potential number of Uvea saved ie estimated as ipproximaiaty 213. Based on continuing exoosure* at currently existing condition* for t yoer. he potential number cf lives saved 1* estimated si approximately 420. Also. OSHA hat etiimated that the promulgation uf an ETS setting e 03 f/cc PEI. may avoid 3723 cancar death* assuming 20 years exposure 10 asbestos of the currant workforce at currant conditions end 7813 cancer des'hs assuming 45 yean exposure. OSHA Is swart, of course, that Section 6(c) of the Act limit* the effective time of *n ETS to 6 months, and OSHA conclude* that a grave danger exists end an ETS ia necessary even if OSHA focuses exclusively on this six month period. However, tha Agency believes it 1* appropriate to calculate benefits deriving from in ETS using lifetime risk* from 20 and 43 years . of exposure to the PEL of 03 f/cc established by tha ETS. Although the ETS expires within 5 month*. Section 4(c) require* that rulemaking on a permanent standard also be completed within 6 months, so that there will ha no gap io protection for exposed employees, ia OSHA's experience and judgment, complying with this statutory diractiv* and computing rulemaking for a permanent standard within 6 month* of an ETS haa and can be doom OSHA also believe*, based on Ha experience that it is vary likely that the PEL established after 4(b) rulemaking will be no higher than 03 f/cc. ths ETS limit Thartfore. OSHA believes that the ETS will result ia a reduced Lifetime worker exposure* of 03 f/cc or tower for 20 or 45 yean. and that tha benefits derived from these exposure rvducnon* for these time periods are appropriately attributed to OSHA's pr muigation of this emergency standard. * Employee Exposure*. To dsnvs these ssttmatss of numbers of lives saved. OSHA depended on its knowledge of tha following factors: (11 Th* employe* exposure levels from ths ambient asbestos air concentrations in tha workplace: (2) th* number of workart exposed at th* various asbestos levels: (3) the duration of the exposure: and ;4) the probability of the disease lor tha nsk) associated with th* cumulative exposure. Employee exposure levels are conventionally measured ia terms of th* number of asbostoo fibers that era 3 microns or moro in longth in on* cubic centimeter of air. f/cc In mat* term*, tn ambient concentration may seem to be 1 ' small amount 01 asbestos. However m physical tarns. 10 f/ec equals 2.300.000 f.ben par cubic mater (f/m*) Humans :nhal* (bout on* cubic moter of air per hour, depending on degree of physical activity. Thus, at this concentration, a worker would inhale roughly in 000.000 fibers. 3 microns or mure in length, over an ognl hour workday. 51092 Federal Regisler / Vol 48 No. 215 / Friday November 4. 1983 / Rules end Regulations X'ow --Oependuia on (he industrial proerts. up 10 rsiauiOO edtblioaal ssbrsios fillers ln> than i microns in length mey also be inhaled. Mumin* that W* a# airborne Iwtos fibers ar* ln than S aucron*. OSHA continues to use the term, f/ee. for convenience but cautions that the numerical estimatn of air concentrations erven in these terms ate only one way of viewing asbestos concentrations and should not be evaluated without interpreting the meaning of the units. OSHA used existing information to estimate worker asbestos exposure in isch affected industry. Data sources included government contractor reports (Ex. 84 OOt and Ex. 84-000). venous studies reported in the literature. NIOSH Health Hazard Evaluations, and OSHA compliance'data (Ex. 84-183). OSHA reviewed the infoirmatioa and decided to use the 1900 Research Triangle Institute |RTT) report (Ex. 84 000) as the primary basis for exposure estimates because tha RTI estimates appear to OSHA to be the most comprehensive in addition. RT1 used a large number of different data sources to make their exposure estimates, including interviews, existing documentation, and mdustrial hygiene surveys of worksites. Using the RTI report as the primary reference. OSHA compared RTI data with other exposure information available for each industry. For example, tpectfic reports were found for esbestus cement manufacturing (Ex. 64248).' - '"ie manufacturing (Ex. 84-207). removal of sprayed asbestos material from buildings (Ex. 84-262). and brake repair (Exs. 84 261. 84-296). The Asbestos Information Association provided data concerning exposures during field fabrication and installation of asbestos cement pip* and sheet in controlled condition* (Ex. 04-295). The Environmental Sciences Laboratory (Ex. 84-002) also mad* beet estimates of worker exposure to various industries for 197S. In addition. OSHA used its own field inspection experience to estimate exposures. OSHA reviewed selected case files tnd obtained information that listed OSHA asbestos measurements during compliance inspections from 8/1/ 79 lo 5/31/83 (Exa. 84-354. 84-333). OSHA adjusted tha RTI estimsta as appropriate, based upon a qualitative judgment aa to which data boat represent existing exposure conditions. OSHA's exposure estimate* are baead. therefore, upon a substantial data baaa and upon constdarabia experience m enforcing tha existing asbestos standard. OSHA used lha employe* exposure levels in each industry to calculate lha number of deaths svotdsd by reducing the exposure from current levels to the emergency PEL Altenutivs exposure distribution* used for sensitivity analysts will be provided in tha Preliminary Regulatory Impact Analysis. OSHA behaves that tha axpoause estimates are relatively good, given the state of the ait of worker exposure estimation techniques and data available today. OSHA is not aware of any other available cunent exposure estimates. Industrial hygiene reports of operations in ths same industry, but at different work sit**. invariably report different asbestoa exposures among the workers. OSHA reviewed these reports and mads decisions regarding typical industry practices. For soma operations, such as breka refining. several reports were available with complete descriptions of tha working environment and OSHA was able to use these to maka direct expoxur* estimates. Other reports, such as "Removal of Pre-formed Asbestos insulation' (Ex. 04-296). described careful processes for asbestoa handling that did not appear representative of the methods used throughout industry, sines tha reported air concentration* wart not consistent with other report* showing higher exposures (Exa. 04-300.04-202). Table 1 shows OSHA's estimates of employee exposure to asbeeto* by industry segment Federal Register / Vot. . No. IIS / Friday. November 4. t!MU I Rule* ami R.viUiiocu 51093 ( sum fadarai Regular / Vol. 4M So J15 / Krid.ii. NovrmUr 4. I "Mi / Kuli-o <<mi R. oil.ilmiu il A. \ A a < ;i \ i % }. a \ i i i 1 W 'Siiiar?Ci*fJ5 ril`iis.1': < * w - * * '.IS-*" * rts5 !; Ms o ir.-t551!-' f is s*w S !?1s* 2 * 5 CO i t 5 S <_r c_r cr Federal Register / Vol. 48. No. 21S / F.-^ay. November 4. 1983 / Rule* and Regulations 51095 Oa i from OSIIA'i MaiugMini Information System (MIS) mcfaifcs a list o( all jsbestos samples reported by OSIIA Held stafT during June L \9T to May .11. 1983 IE*. 84-3331. Owing this pertitd. u*9 cighi-bour time-weighted average ITWAl samples warecollected in many different industries. Of the M8 samples. 731(77%) were below U f/oe 1S8 (18 4*C) fell between 0.3 (Ac and 24 flee: and 62 (84%) were above 2 f/ec OSI IA also reviewed the MB summery report where the measurement dale were grouped within Standaad Industrial Code (SIC) classifications (&. 84-334). All these data contributed in the development of OSHA's beet exposure estimates. In conclusion. OSHA has used its experience in enforcing the casting asbestos standard to determine the best estimates of worker expostme at the industries. On the whole, in rarepanson to other toxic substances pennant in the workplace, asbestos sxpoaM* information ta well reported Cven that OSHA expenence is considasnbJe. OSHA believes iu estuna ten ae reasonable and sppropnatn.nad provide a satisfactory basis for jui%ifis regarding the extent of risk rereung in workplaces. OSHA acknowledges, havener, the! the sxpoture infonnsnon crowning asbestos removal and remoanan in the construction industry is lereasetain then ths other estimates. OetpiMi uncertainii'aa in qualifyingonseture in the demolition/removal cnagmy. OSHA feels that this beat eetimatwiabnaad upon evidence that is both wensbls and the best available. Furtaiaun. OSHA believes that any chwigaa made to the esiimate as a result effttae uncertaimties would not beeffa sufficiem magnitude to winets change in its basic findings. Z. Calculation of Civet rare/and Oiseat* A voidtd. The benmBapovidad by (his ETS consist of caneredhuthu sad disabling aabeslosis avoided Hba estimates of deaths avoided 1glowering of the exposure limit by the megsocy temporary standard are baamdun the mortality rates developed la da risk aseessment discussion. To passesta the expected number of excess dbrehs attributable to tsbettoe in the OS. workforce, the expected rate of mortality at r...h exposure luvvl was multiplied by the population exposed at that level. The expected mortality rate from eech exposure level was dtnvad from OSfiA's quantitative risk analysis (Ex. 80*390). The expected number of deaths at die reduced PEL was then subtracted from the expected number of deatha at Be current worker exposure levels lo determine the estimated number of deaths avoided by reducing die permissible exposure limit The benefit! are expressed in terms of estimated dMlhe rather than disability because the type* of cancer associated with asbaasos exposure have very poor sunrise! rate. An exiamla of such a calculation follows. Tecalculata the lang cancer deaths avoided during one year of exposure Pa worker popeiaiion in the consiructlea industry who are engaged in Ihe instadanon of asbeetos camam sbaef Population-1783 (Table 1) Estimated ferrant Expoawv Level -to f/cc (TaMa 1) Ealimaiadhng cancer nsfc for on* year at 3 f/ao-144/100400 (Table 11) 1. Calndbda axpectad daatha for installer* ofA/C sheet hawing one year of expoaaoeat 2 f/cc exposure level: PopuUlkaatx risk-expected deaths (1783) (M/lOUXO|-244ar appnmmalaly three deaths among inateihm. 2. TilssIhM expected daatha for inatallerarfA/C ahaat at PEL of 04/ce for ana yoreuf exposure: ruliimadii'B at 04 f/cc--36.1 par 100408(Tbbla 17) PopuletiM x risk--vxpected daaths (1783) (3AI/,700.0001-0.8S or appro life ly one death among mstalim 3. Caladhte lung cancer dutha averted arllaes saved (at A1C sheet inatal]ere hg seducing eirp--ire to 83: subtrees eaaeciad deaths at 04 f/oe from thawaxpectad at 2f9ae (244)-(MB-14 or apfammataly two Uvaa aaa^ The aatentad benefits dwived tram exposure abactions to several PEL'S which OSMia corsidarog for s flnel standard amepresented aTabla 2. These benefits represent Hm rttimatad number of rancar daatha avoided from those expected due to 20 years exposure at the estimated current exposure levels assuming worker exposure began ai age 23. The benefits ware calculated using e base of 20 years sxpotura because, as stated earlier. 20 yean is an estimate of typical lifetime exposures for some . workers. Exposures of 0 months, one year and 49 years duration are also used to show the grave danger end the need for ihe standard, baaed upon a 0.3 f/cc PEL (see Table 3). For Table 2. OSHA bases its respirator assumptions in ihe construction industry end shipbuilding industry on its enforcement expenence. on its familiarity with ihe indusints. irads unions, and industrial hygienists, end on available studies on this subiect. OSHA believes that these estimates may overstate the degree of respirator use. This would lead to underestimation of benefits of the ETS for the following reason: The fewer workers us compliance with the currant requirements far respirator use for ambient exposures exceeding 2 f/cc the greater the potential benefits from an ETS mandating that workers be trained regarding the significant risks from asbestos exposure end the importance of using respirators. Also, workers currently using roapirulors will benefit by further reductions from 2 f/cc to 0.3 f/cc However, if respirators mandated by the ETS are not used properly or consistently, than the number of cancar deatha avoided is an overestimate. To teat the result* OSHA also calculated the benefits assuming that oil C/i shipbuilding/repair and construction / --t rvnovaUon/oamolilion operations CD comply with tha current scandarc. All of ^ the shipbuilding/repeir workers would tkua be protected by respirators which would reduca exposurea to 04 f/cc The construction workare would have an <~3 exposure of 2 f/cc Tha benefits of reducing tha PEL to 04 f/cc would. 03 therefore be calculated as tha difference between axpectad daatha at 2 f/cc and tha axpacted daatha at 04 f/cc for all workers in these segments. Tabie 4 shows these benefit estimales. ima cosa miwoai / 5109C * < sss a a OK Io a f1 *5- IS Federal Register / Vul. 4& No. 215 / Friday. November 4. 19A3 / Rule* .ir.J Ki^ulutmns 33 *5 3 --* ^-- 5 w ^^ a hm m i* 22 2i2w :>% 1* llW :i* Is *5 av* i2iti-sl3 H 5! !! 1? i5Jk *s= 5-f jf s \ Il i -M a I w !1 * !* Ii1 *33 s1K5 ?|!!s li?1! M .* Sine!#_ 2 i tS _f%22* ^ a i -- # STI *32 *! 8-i JI *55 ;s: !** mw mim S'S 2*S `f' XH i?:* Us I SU :5- 1 -J.itijjsssr hi >55 ; l"i ! .:: fst i s * a .3 3 s^ -a ;3 I !1 1 *i ! 8 5 5 2 - ~ 33 ^ *3a || % N 1^ N . 4N1 3- *5 ^2 3 m!* |1!! 1 4 Z i1i i 3S I ; i w >. I1 I! l! 3 iS 1i"8 Ks i's 3V -51 pi Jss # "* U- 5:1 ii Sfs s-:i if* 8*2 -ii *2 ::2 s!"* SI ||2 !w *si 5s % V J3VJ 3 - si S' I18 :si 2* hi 11 4 00 --t CD CD o <_n CO CD CO Federal Register / Vol 4*. So. 215 / Fr.duy. N'ovcr.ibcr 4. 1963 / Rules and Regulations 51097 Although the results in Table 4 show ltwar benefits OS1IA believes the number of deaths svoided under this icertarlo. 60 for six months. 163 for t >cor. 2416 for 20 years, and 3513 lor 43 years indicate a grate danger and necessitate this FTS action, Table 4 Cancer Oeatns Avoided mtn a O.S f/cc CTS Assuaing CoopI lance with tne 2 f/cc Standard Industry Sector 6 iaontns 1 year 20 years 45 yeirt nnary atanuf sc taring 2 8 117 174 ieconasry Manufacturing 17 11 471 684 sutoanttv* Aftermarket 4 8 134 194 ShlpnuiIdtng/Repair* Construction** 00 57 ns 0 1684 0 2461 TOTAL 60 162 2414 3611 *0ShA assures out use retire inmis try sector coaplitt vttn the 2 f/cc standard tnrougn us of controls or respirators capaOl* of reducing exposure to O.S f/cc. **Q5HA assunes tnat tbe renovation and deaolttton industry sector's are protected to 2 f/cc . by use of'half uU air purifying respirators. 3. No OtherAgency Action /a Adequate To frotect Empieyeee Againtt Thu Crave Anger. OSHA believes that Congress intended that tbn CIS authority mary be auraiad whan OSHA determine* tbnt a grew danger la presented and when He psnviatone of the CTS are oeftad lobe m immediately aCrede* means of protecting ii^ioyaii agairet snch danger. OSHA. however. bee evHntsd the potsatial capability of ether possible actions to resfcca the riafc bairn aabostos exposure. OSHA baa determined that no other agency action short of Issuing this CTS which compels an immediate fourbid exposure reduction wil auffldantly protect employees against tha grave danger of developing asboeres related disease. In meting this detremmattoo OSHA considered tha uaefulneta of napping up enforcement of tha current tabestoa standard, and initiating a 6(b| rulemaking proceeding to permanently reduce exposure levels. These actions will be discussed in turn. OSHA noise thet these actions are not mutually exclusive, and in fact OSHA la both stepping up Us enforcement activities and embarking on a required 6(b) rulemaking as coordinated ecdvtUeeJn addition to issuing an CTS. (a) OSHA first concludes that merely increasing tin enforcement of tha current asbestos standard would not suffleiaatiy reduce the grave risk of asbestos-related disease to exposed workers. Even if snch tnrrassod enforcement resulted la immediately reifora compliance with the current 2 f/cc standard in all industries, risks to asbestos-exposed workers would remain unacceptably high. As limed above. OSHA hae esumaied that at a 2 f/cc lave! employees exposed over working lifetime ol 46 years are predicted to have n excess risk of dying from cancer of 6* in 1000 and of contractu:, disabling asbostosis of 60 in 1000c employees exposed over 20 years are predicted to havo excess cancer risk of 44 In 1000 and a disabling asbostosis risk of approximately 22 in 1000. Even at exposures lasting om year, an estimated 3 employees out of 1000 ere predicted to die of asbestos reitted cancer, and there is also additional risk of developing asbostosis. Risk* at tho 2 f/cc level have been acknowledged aa unacceptable by other governments which have reduced their permissible levels below 2 f/cc. To *sOrnate the number of lives at slake If only the current standard were Immediately enforced Instead of compelling 0-3 f/cc level through this ETS. OSHA made other calculations using certain assumptions about actual compiiancs levels. For thia analysis. OSHA assumed that ail construction, renovation and demolition operations comply with the currant standard to that workars in this industry would havo exposure* of 2 f/cc. Tho difference in tho number of deaths avoided by compliance with the 2 f/cc standard compand with those avoided bom compliance with tbs 06 f/cc ETS is still vary high sad show* that asbestos exposure even *t 2 f/cc represent* a grave danger to such exposed c/ employees. T*bl*4 tats forth the result* __ of these calculations. Thus, for a 20 year __ period of exposure. OSHA estimated -- that merely ensuring compliance with c: the current 2 f/cc limit may cost 2416 employees their lives. For one year of exposure. OSHA estimated that 162 ^ employees may die if exposures are not __ reduced to OlS f/ec. assuming full compliance with tha current 2 f/cc limit. <~ OSHA believes that these benefit! (l.s. lives saved) represent tha lower bound of those that would result from tho ETS for two reasons. Half mask respinton which may be used at air concBitredocs of 8 f/cc to comply with tha currant standard may not effectively reduce employee exposure below 2 f/cc Further undar the ETS. half mask ratpinton may only be used in workplaces wW* concentrations do not exceed 6 f/cc. Employ***, in workplaces between S and 20 f/ce mugt use more protective respinton under the ETS: hence, it Is likely that their actual 'V ( i t 1 ( 31008 Federal Register / Vol. 48. No. 215 / Friday. November 4. 1983 / Rules and Regulations expuvurrt may be reduced to Mow U f/cc and the benefits uf the CTS will be comvponijinjiy increased. Farther, an ETS by nature of the action melt and me accompanying enfurcantttn program. m dl undoubtedly boost tha incoalives to comply with all protective prevtaione of tha asbestos standard. (b| OSHA rafectad relying on martiy I spinning Section ttfbl ruletnaJung proceedings lo revise the standard to reduce tha PEL at an inadequate response to the grave danger faced by axbestos-expoaed workers. Beginning rulemaking proceedings result* in no immediate workplace changes. Employees would still continue to be exposed to those conditions which define a grave danger fur el least tha pendency of thq rulemaking. In OSHA'e experience, completing 6(b| rulemakings not inuatad by an ETS concanung hazardous substance* can take many years. For sxampla. tha coke ovaa emission standard took approximately 3 'i > ears, tha laad standard. mors than S years and the cotter, dual standard, more than 4 years. Thtae period* do not include any of the addiliooa! delay* in (he effective date* of OSHA standards that ware due to judicially imposed stays, which have resulted in delay* lusting several years. Under the moat favorable arcumstaocaa. however. . OSHA believes that it it possible that a saction g(b| rulemaking limited Is the issues raised hernia might be completed in approximately one year, absent an ETS. Aa shown above, tha senmated risks of developing aabeatos-reiatad cancer due to exposure for on* year under current condinont. are still extraordinarily high. The additiuuei risks of developing aabetiosi* due to one year's exposure under entreat conditions, although quaouBad with las* certainty, are also more than significant. OSHA also beiinva* that tha risks of six months exposure, approximated by taking over half of the on* year risks under current conditions, ate* are unacceptably high. OSHA amphamf as staled above, that QSHA's expertme* snows that without an ETS. proceedings laadicg to a permanent ru-ulth standard are uniikaly to bo completed within a six month period. The xpUnalto.i of OSIIA's capability it produce * sturxarj within ti months of an ETS lies in tha urgency generated by OSHA's finding ol a grave danger, the existence of a specific statutory dfu'Jhn* to complete a rulemaking w.thm 6 niuntits .'id '.hr need m prevent u g.tp in pniu-ciion between the expiration uf thu ETS and the imposition uf the permanent standard for a substance already determined to present a grave danger. OSIIA also believes that it is helpful *: evautai* the extent of risk resulting from lifetime exposure periods ofZO end 4S year* ui the absence of this ETS. A* shown in Tables 10 and 11. these risk* are extraordinarily high. 4. Other Factors Indicating a Seed for an ETS. Although worker exposure toasbestoe has been declining over the year*. OSHA believes that exposure conditions will continue to present grave danger in the near future unless an emergency standard is promulgated. OSHA bases this finding on its evaluation of exposure information, asbestos us* statistics, consideration of the nature of industrial exposure today, and the degree of compliance with the current standard. Although OSHA anticipates a decline in use of asbestos in products, this decline wiU not materially elTact asbestos use in the near future. The extensive ton litigation regarding asbestos and the awareness of health. effects associated with asbestos exposure provide! strong inducements for producers and users of products to switch to substitutes for asbestos. In fad. asbestos consumption has declined over dm years as shown; US Contempt ton rear Pstttrn (1000 19/S 19?8 1977 1978 1978 1988 1981 1982 ss< 659 672 619 S4I 2*0 249 248 Worker aslxrstot. exposures will ccslinua however. tor many years n the future because substitutes for some produde do not appear immediately available. For other products, old replacement pans wiU bo needed for many years. For example, automobile manufacturers may switch to oofreebesto* brakes and dutch facing in new vehicles in the nsxi several years. Old vehicles, containing asbestos parts, will remain in us* for many years thereafter. Paik et sL found over half o( all multistory buildings surveyed (88 out of 1ST) contained sprayed on asbestos materiel (Ex. **282). The potential for asbestos exposure exist* as long as asbestos remains in thee* buildings. Renovation work in the building such si relocating wall* and electrical wiring, will result m continued exposure for carpenters, painters, eiecuidans. laborer*, sheet metal workers end others. Therefore. OSHA does not believe that maior exposure level reductions srt bout to occur in the near future. The trend towards reduction in asbestos us* and asbestos exposure has been a slow gradual process with the excaption of instances where the government intervened. For example in 1971 the EPA banned use of sprayed on insulation containing more then 1 percent asbestos. Without OSHA acting at this time OSHA predicts that the grave danger conditions will persist certainly during the penod required for OSHA s issuance of e 6(b) standard, and probably for many years thereafter. V The Need for the Specific Provieiaaeofthe ETS. Tha provisions of the ETS require the employer to us* sny method of control to reduce employe* exposure to 0J f/cc and to tram workers concanung the hazards associated wuh asbestos and procedures for reducing the nsk. These provisions must be implemented immediately. OSHA believe* Utey are greatly needed to afTard employees meaningful protection As the benefit section explamed m detail, compelling exposure reductions through an ETS will result in great number of live* saved. In addition, as stated earlier OSHA believes that its astimates of tha degree of compliance with respirator requirements in the construction and shipbuilding industry may overstata the degree of present respirator use Thus. OSHA may be andanteting the benefits to be deminl from an ETS. tnd hence the need for such an ETS to be promulgated. In addition. OSHA't estimates of exposures in demolit on and renovation segments cf the construction industry are approximately 20 f/cc Because under the ETS the PEL is lowered to O.i f/cc the airborne ronriT.tration at which more protective UCSOOOiS . v Federal Register / Vol. No. 213 / Fridny. November < 1983 / Rule* and Regulations * 51099 ZZG9 0 0 0 1 S i respirator* (with a protection (actor receding 1(1) must bs worn drop* (root 20 f/ce (10 timet the former PEL of 2 f/ ccl to S f/ce (10 tit-- the new PEL of 0-a f/cc). Therefore OSHA believes that more workers will wear awes protective respirators under the ETS than under the current perms--it standard, that 'thetr actual ispcs-- levels will be reduced to below U f/cc and consequently that their risks will be reduced even more dkaa the calculations indicate. OSHA finds also that requiring a raining program to be instituted as quickly as possible is one of the most effective methods of maximising the beneficial impact of die exposure reduction end of all lha protective provisions pf the current standard. Thus, tha content of this ETS hat been chosen as the moat effective short-term strategy to reduce asbestos risks which will be ccepied and implemented. 0. Conclusion. OSHA finds that workers exposed to asbestos in tha workpiece at existing exposure , conditions need this emergency temporary standard to protscr them from tha grave danger presented by these conditions. OSHA finds that by compelling a reduction in exposure to 0.5 f/cc for those employeee presently exposed over that level, many lives will be saved. Training imposed by the ETS will enhance tha risk reductions, although quantifies!-- of that additional reduction cennot be calculated. OJ f/cc in the lowest feasible level achievable through this emergency action, where short-tan implementation of the controls is leqintsd. Only by issuing an ETS compelling reductions in exposure levels below tha current permissible limit of 2 f/cc can OSHA bring about adequate reductions in risks. The sdmioutnttve ecuen of stepping up enforces--! af tbs currant standard is an iaadeg--s response to OSHA's finding that --rent conditions present a grave dangmt OSHA does not bofiawe that any significant reduction sail occur within an acceptable time ported without this emergency standard action. OSHA baa observed a gradual redaction ui asbestos use. but in lha Agency's experience, significant sod rapid exposure reductions nasally occur in response to standards. The provisions of ihe ETS will signifiesndy reduce the nsk end reduce it quickly. Tt.srefore OSHA has determined that the ETS is necessary to reduce the grave danger. IV. Occupational Health Data fibrosis is absent and do not seem to A. Introduction reflect the seventy of pulmonary parenchymal disease. Pleural I. Asbestos-imbtsd Diseases. calcification is also commonly found in Asbestos sxpoanre can cause a number persons who hava been txposed to of disabling and falsi diseeses. Among asbestos (Craighead et aL 1942: Ex. M- thsso diseases -- lung cancer, cancer of 033). the mceoihsliel fining of the pleura and peritoneum, andasbestoalg. it is also likely that asbestos increases the risk of gastrointestinal cancers. Of aU ihe diseases caused by asbestos, dsath from lung cancer constitutes the greatest health risk for American asbestos workers. Lung cancer has been responsible for over half of the excess mortality from asbestos exposure in some occupational cohorts. The relationship between lung cancer and asbestos exposure he* been established by numerous cpidtmioiogic studies of diverse poops. Asbestosinduced luttg-canosr usually has s latsncy period In excess of 20 years and may be diagnoeed at an earlier eg* than for non-exposed persons (Craighead at al_ IMS Ex. M-tS). Faw eaaet of lung canctr are curable despite advances in medical and surgical oncology. Only 9% of lung canear patients surviv* five or more yean tflar dUgnoeis (American Cancer Society, tat Ex. 94-180L Aabestoe expoeure acta tynergittieaily with cigarette smoke to multiply the nek Asbestos!* Is pulmonary fibrosis causod by the accumulation of asbestos fibers in tht lungs. Adverse sffecis of ttbeslosis range from shortness of breath upon sxsrtion to cyanosis, effusions of serous fluid, respiratory failure, cardiac decompensation, and dsath. Often, asbestos!* is a progressive disease, even in ihe absence of continued exposure. Symptoms of disease ere shortness of breath, cougn. fatigue, and vague feelings of sickness. When the fibrosis worsens, shortness of breath occurs even at rest. One clinical feature of early asbestos!* s* well ss other lang disease* is end-inspiratory crackles (rales). Diagnosis of ssbesioais is based upon the presence of characteristic radiologic changes symptoms, rale*, other clinical features of fibroaing lung disease and e history of expos-- to asbestos. Ogarettc-smokug asbestos workers may have an incraaaad riak of asbeatotis relativs io non-smoking esbestoe workers. (Craighead et ai_ 1982: Ex. 54-033). of developing lung cancer. MeeotheHo-- alee haa been So-- epidemiologic studies havs observed increases in esophageal. cooduaiveiy shown to be aaaociatod stomsdL oolo-rectai kidney, laryngeal, with ssbssto* by many studies, la some pharyngeal, and beeestl cavity cancers. asbestos-exposed occupational groups. While the magnitude of increased of deaths have bean cancer risk for these sitae is not aa great attributable to BMhpwiit as for lung cancer and mesothelioma, mesothsliomss Malignant the inoeased risk is nevertheless of mesotheliomas of the pleura and considersb!a importance because of the peritoneum asu extremely rare in high background rats* of some of these persona not exposed to asbestos. tumor* in tha general population. A 50% Generally, a latency period of at least 25 increase in a common cancer such is to 30 yean is required in order to colo racist cancer results in many more ebeerve mosmheli--s in an deaths than a 50% increase in a rare occupational cohort. So-- victims of cancer. Colo-rectal cancer, if detected amsothelio-- have had e latency period and treated In an early localised ttsge. weeding 40 year* sine* their initial has e live year survival rate of about expoeure m asbestos (Craighead et sL ttt Ex. 04-033). This form of cancer is 70% (American Cancer Society 1983: Ex. 80-1801- Surgical end medical treatment rarely curable and is usually fatal within is less successful for the other sites a year altar diagnosis. There is no listed above. evidence for a relationship between Adverse effeeu from exposure to cigarette smoking and mesothelioma asoesioe heve been obeerrtd in worker* riak. involved in asbeetoe cemer.t pipes and Asbestos exposure can cause pleural tkingies manufacturing (Enteriine et si.. and/or other pulmonary disease. Pleuiei 1973a. 1973bt Weill et ai. 1979: plaques are one of the markers of FinkaUteia. 1992.1983) (Exhibits 84-122. exposure and may develop within 10 to i 84-123.85-208.84 014.84-2401. albedos 20 yean altar the initial exposure. / mining and milling (Walter et aL 1980 Raques era opaque patches visible on Liddell et aL. 1977. McDonald r aL chest X-ray* that consist of danse strands of colLgenconnective (issue I990i Hobbs et aL 1990c Xichulron ct al.. 197*. Rubino et L 1979) (Exhib it 2-21 ornteinl lined by mesotheiial cells. Ail 84-039. 84-C6J. 84-132. S4-07L 84-08CI .uirjnerciai types of ssbssto* induce asbestoe textile manufacturing (Doll. pLqurs. Ptiques can occur even when 1933: Pete a: aL. 198a Berry e al- 1979. 51100 Federal Rosstat / Vol. 48. No. 215 / Friday. November 4. 1983 / Rules and Regulation* Dement el aL 1883) (Exhibit* 84-twa 94- joint MOSi (/OSHA Asbestos Work 189. 84-020. 64-037], insulation work Croup stated that there was no level of (SelikofT el *L 1979) (Exhibit 84-0801. xputurs to asbestoe below which shipbuilding (SclikofT et aL. 187V: Blot et clinical did not occur end el- 1980: Tagnon et aL 1980) (Exhibit* rscoamended s PEL of 0.1 fiber* per 84-091.84-109.84-182). and in a variety cubic centimeter (0.1 f/ccL based on (he of asbestos product* manufacturing Umiutions of current technologies of induatriea (lose* at aL 1980: Henderson measuring air concantrattane of and Enteriina. 1979: McDonald and asbeetoe. The 1979 report of tho McDonald. 1978: Seidman at aL 1979: Advisory Committeo of the Health and Robinson et aL 1979: Achesoa et aL Safety Commission of the United 19811 (Exhibit* 84-138. 84-048. 64-184. Kingdom, hereafter referred to in this 84-087. 84-082. 84-103). section e* the UX Committee, led to tho It should be noted that 2 fiber* per cubic centimeter, which ie the current reduction of the British standard far asbasios to 1 f/cc for chrysotils. as f/ec OSHA standard, is equivalent to 2 for smosite. and 0:2 f/cc for oocidolit*. million fiber* per cubic meter of sir. Currently, it appear* that the United Because human* breathe in about a Kingdom may lower the PEL for cubic meter of air evanr hoar, depending chrysotils to 08. on physical exertion, the current OSHA 2. Evaluation ofRisk. OSHAs first PEL for asbeetoe allows workers to tap In analysis of risk of disease from inhale 2 million asbestoe fibers per hour exposure lo * potentially haxardoo* during an 6-hour work day. For the *aka gent is a qualitative evaluation of of brevity, subsequent discussion In this beatific data. This evaluation involve* preamble will express exposure in terms reviewing human end experiments! of libers per cubic centimeter (f/cc| studies to consider such factors aa rather than fiber* per cubic meter. Nele." The cenrat OSHA stsedstd iadede* aabsstai Bbete ataremessn ar men in lenaiik thereby odudiat rimnar overall study design, methods of data collection, biologic plausibility of findings, consistency of findings from different studies, temporal correctness fiber*. Since as te set* ef siikarae asbestos of the association, and other factors as fiber* in thertar than S mctomoMs*. well a* general adentiBc judgment worker* may inksla p te WO millina tsOwMe fiber* par hem derma aa * hear workday. Subsequently, after a specific agent he* been judged te be hisarrlmia. the quantitative expoeura response Siaea OSHA't publicstkm ef a notice roiationahlpe between the agent and of ptopoeed rulemaking in 1871. disease can be investigated Tb# additional studies have mnfirmod that iveiinble data on air concentrations of asbestos expoemu causes a high risk of . the substance or biological Indices at cancer, la addition, much ssora complete exposure. such as fiber content* within data on the nature of lines response lungs, can be reviewed far cohort* of relationships far asbestoe induced vorksn demonstr*tad to have an diseases are now availsbis. These increased risk of dispose. If worker* studies generally Indicate that the PEL with an observed excess risk of disease ret by OSHA in 1972 is inadequate to have received cumulative exposure* protect trbestoo-workers horn either permitted by the current OSHA lung disease or cancer. permissible exposure limit then a The following agendas and potential significant health risk from orgetuxationa have reviewed the health exposure to tho PEL has bean data far asbestos: International Agency mtabllshed If the workers with for Research on Cancer (1AAQ (1977. observed excess risk received Ex. 84-121). Organisation far Economic cumulative exposures above those Cooperation and Devefapmanl (OBCS) permitted by the current PEL then risk (1979: Ex. 84-337) NIOSH (1979.19H. from the current PEL may be estimated Exhibits 84-139 and 88-00). Advisory from risk observed at higher levels-by Commit:** of the Health and Safety aing dose-raepoea* extrapolation Commission of the United Klngriom models. (1979. Ex. 84-218). the Chronic Haxaid The lection. Epidumioiofic Eviasnea Advisory Penol on Asbestos (CHAP) on Risk from Exposure at the Curran* (1983. Ex. 64-258). and tha U.S. PEL will discuss the extent to which Environmental Protection Agency (1982. excess risk has been obssrxsa from low Zx. 84-180). All of these groups have exposures to asbestoe. Section V, concluded that there is e causal Quantitative Risk Raaiysis. will diecues relationship between aebeetus axpetun tht prsd.'Ctioa of exeat* risk from low and tht developtreat of cancer and non. asbestos exposures Ming drew- malignant rerpiretory disease. NTOSH extrspalstioa models fcaosc or studise r.tcommen Jed rrd action of the fL far observing excess risk in human*. OSHA aspeeroe to 0.1 fiber* p*r cubic considers that both risk* observed by centimetar (0.1 f/ee) in 1970. In 1980. e studies end risks predicted by does extrapolation models are valid indicator* of the existence of significant health risks. Exposure date frequently are not available far workers exposed before 197a Where historical expoeura data are available, the data often have suen limitation* at having boon collected and analysed using industrial hygiene technique* no longer in us* or having been collected in only some area* of the worksite or having been collected on only a few occasions. Therefor*, of necessity, estimates of dote-response based on epidemiologic studies will have a fairly broad rang* of uncertainty. OSHA must examine the best available data on exposure-response to emv* at a determination of significance of risk, despite inherent and inevitable uncertainties in the data. The currant 8-hour time-weighted average PEL for asbeetoe of 2 fiber* per cubic centimeter (2 f/cc) sgvisagee that worker* will not receive a cumulative exposure exceeding 100 f/cc-yeere (* f/cc x SO year* of occupational xposure). For asbestoe. OSHA believe* that a number of studies suggest that increased risk of lung cancer, asbestos!*, sad mesothelioma have occurred from cumulative exposures estimated as dose to or below 100 f/cc-year*. Nsis OSHA tyytcaOy ass* 41 year* u tk* parted of fail worktn* lifaflm* far parpoee* of qaaettiying risk from expaaar* te tacc ***!. far esbeesas. many eaeeuate have e*d JO yoars lo rapAwmt a hfl worfcie* lifetime. Thai, both 4S yaws a* txposui* ted M y*ar* of sxpoaui* ora asad is this dacanmt far the perpese af snslyting Jew seeponw isisdaesfape far sebeetae. la the** studies, the cumulative exposure* resulted from exposure /eve/s greater then tha currant CSHA PEL of 2 f/cc for in 8-hour day. For exempt*, workers who accumulated 100 f/cc- yeen co-ud have been exposed to an average level ef S f/cc for a period of 20 year*. Section 8J3) below, discuss** tho rptdsmioiogic evidence for nek from low exposures In men detail. OSHA believes that * significant health riak has bora observed far cumulative axponrw that could be accumulated by worker* exposed te no more then tha present PEL of 2 fiber* per cubic centimeter (2 f/cc). Estimates of cumulative exposure are approximations of total doe* received by a worker during tha petted of employment involving exposure to ifbesloe. Cumulative exposures generally an estimated by multiplying ihs varying intensities of exposure, such t* Lie 8-hour time-weighted average*, by tha Bomber of year's exposed. Most theories of the mechanism of co ;6 S (i0 0 1 S a *] l GS0 0 Qi S . Federal Register / Vol 48. No. 215 / Friday. November 4. 1kb3 / Rule* and Regulation* 51101 i irci:u>yera.'*i* iluuu that the risk of irunsformjtion of target cell* to cancer cells increase* with mere**** in the ioi*1 dose. Exposure* received after such transformation hat taken place may aid the development of cancer, but have not caused the cancer. Thus, in some instance*, using Intel cumulative exposure may overstate the exposures sufficient to produce increased cancer nsk. For this reason, some epidemiologists onut tho later years of exposure to a carcinogen in analyte* of mortality in relation to cumulative exposure. In addition to cumulative exposure. ntensiiy of expoeuie can be examined m relation to dlaeaoe. Intensity of exposure ta often approximated by hour time-weighted averages (TWA's). The OSHA PEI. ofJ fibers per cubic centimeter (2 f/cc| as an 9-hour TWA has only been in effect since 19TB. At thus ume. it dote not appear possible to determine whether Intensity of exposure has an effect on disease risk separate from that of cumulative exposure. This is because the current OSHA PEL has been in effect only since 1979. which is an insufficient period to observe soettoe-reiated disease*, which characteristically have long latency period* (in excess ot 29 years). A* discussed in the section. Quontibaew . Risk Analysts. it appears that duration of exposure any have an indnpandant effect on mnaotheUwmn risk. Tho following sections analyze meant epidemiologic and experimental (todies and discuss important aspects of the occupational health data concetning asbestos. 8. Epidemiologic Evidence on Risk from Exooture at the Current PEL ! Conversion of Particle Counm to filer Counm. Currently, personal atnestos sample* of exposed workers are collected with a membrane fUtar. . and fibers am counted asiag a phase contrast microscope equipped with an eyepiece graticule, ts the pout, psrttrisa -re counted mtfaar than fibers, area sample* wsm taken rathm than ' personal temples, and aemplaa went collected using thermal psecipttatnm or midget iapingtrs. These pest industrial hygiene meaaummnnts wars exprtasad i.-. millions of purtsdn* par cubic foot (abbreviated a* mppcf or mpcO. whereas current mraauremenu am expressed a* fiber* per cubic centimeter or per milliliter |'/cc or f/ml). Ccr.version of measurements from mpef o f/cc is not a simple matter of applying 4 sin-fir multiplicative factor dun to the dif.Vnnj work enrirenments ir. which were taken and diftenng enpling methodologies. The factor for com tiling mpef to f/cc has been su^cstcd as ranging from lit to 14 depending on ih* industry studied by the scientists (Kang and Chu. Ex. 54-1: Hxmmad et i.. Ex. 94-277: McDonald. Liddell. Cibbs. Eyssen. and McDonald. Ex. 54-OU). For oxample. using converstoo factors ofLIlalda cumulative exposure of 20 mpef-yeem could rang* from 20 f/ce-yeam to too f/ ec-years. The British Occupational Hygiene Society Commmae on Asbestos conducted a study of dual concentrations measured by current methods and historical methods fEx. 84024). Conversion factors for hiatonoal methods to current methods warn 1:04)7. 1: 2-2. and 14. depending on (he historical method. For asbestos mining and milling, this section will us* the midpoint of the range of conversion factors: t mpef-1 f/ cc. For ssbetto* production and sbestoa cement production this section will us* Hammed et aL's suggested conversion factor of 1:1.4 for mpef to f/ cc 2. Epidemiologic Studio*. Thu epidemiologic anidia* that OSHA interpret* a* suggesting that significant heallh risk baa been observed at low asbestos exposures fall into 2 categories: (1) Studies of household contacts of aabnatno worker*. (2) studios of workers whose exposures wan shodterm, sad (3) stadias of worker* with cumulative exposures estimated to bo dose (o'or below too f/oc-yters. This section summenza* these studies and prsssnu OSHA'* analysis of these studies. A number of studies have observed mesothelioma* and an mereseed prevalence of chest X-rsy abnormalities among families of asbestos worker* [Anderson et aL. Exhibits 54-015 and *4-017; Vienne sad Man. Ex. 94-199. U t *L Ex. 54-tSOL la addition, masethaiieaas haw been observed la . community member* living near asbestos mine* and factonsrfWagnar et L. Ex. 2-21: Nrwhotsae and Thompson. Ex. 54-070). Aadarsan et uL (Ex. 54-018) observed 11U percent prevalence of chaut X-ray abnormalibec including pleural thickening, plaques, pleural calcification, and lingular opacities, among 525 household contacts of. smosits factory workers competed to a 44 percent prevalence of chest X-ray boomstides among 329 control* drew* from the same community as the (.mottle worker*. Controls wen matched to the cast* by age end sex. As of 1979.4 cases of mesothelioma had been diagnosed among tho 529 family cuniiiclt of the amosit* workers. Presumably, family contacts received their exposure to asbestos from dust earned home on the worker's clothing, especially during Ike laundering of dusty cloths*. About a ttffoid inenute in prevalence of pltunl thickening compand to content* was observed in family contact* of srorken with only ons year of expotun within thn amotitt factory. Estimated asbestos exposur* levels of family contacts and community mumbun obstrvud ta be si risk of asbestos misted disease have not been reported. OSHA consider* it very likely that the cumulative exposure* of the family contacts and community members wen less than 100 r/cc-yesrs. Ssidman. SelikoH and Hammond (Ex. 34-0*7) studied the mortality of 520 amotite production workon employed sometime during 1*11-49. Saidman at aL reported that dust concentration* had never been measured In this plant and that the plant was known to haw deficient ventilation systems. Worker* warn classified a* having worked leas than 1 month. 2 months. 3-5 months. 9- 11 month*. 1 year, a* 2 or more years. Worker* a all categories of length of employment had excessive mortality from lung canon-. For example, men employed lass than ana month had a lung cancer sundardsad mortality ratio (SMR) of 297. based an supplemental utepsy- dlniceL and surgicei information. (The standardized mortality ratio is calculated as tbt observed number of death* in thn exposed popuienoo divided by the number of deaths that would be expected in the exposed population, based on mortality rate* of eo appropriate compansoo population. The SMR is frequently used a* an approxunaoon to thn relative rlsk.| Hence. OSHA consider* that Setdman et L demonstrated that exeat* lung cancer nsk could be expenwoed twn by winkers with exposures of relatively short dureQuo. Berry. Cilson. Holme*. Lawinsoha. tod Roach (Ex. 54-090) studied the workers of an asbestos textile factory in the United Kingdom. Berry et si reported in 1979 that die average expostau lew! was 9 f/cc and that 94 percent of men employed after 1930 had "possible asbetiosis." Among men employee alter I960. Berry *1 aL observed l percent prewlenee* of crepitations, "possible asbestos!*." or "certified ssbeitocis" at 37. U, and 93 f/ ce-i ears respectively. Berry *t it. concluded: "in view of these finding* there la no room for complacency about the 2 f/ca* standard < 1102 Federal Repair / Vol. 40 No. 215 / Friday. November 4. 1363 / Rulua and Regulations and tfTo't* fhouJd be continued to reduce asbestos duet to at low a level aa possible. At Ihis stag* it ia impossible to tate definitely that the standard ia inadequate, because its introduction la so recent and it is essential to follow up (roups exposed to law levels In Older la improve the data necessary for the formulation of better standards- (Ex. 94- 030. p. 109V Flnkelsiein (Ex. 64-044) studied the development of compensable (certified) esbestosis among 1ST Ontario asbestoe cement production worker* ia relation to cumulative exposures (f/cc-ytarsV Ai! workers in the study cohort had at least IS years of exposure. Ontario cntena for certifying esbestosis. which results in the award of disability pensions, are not indexible and involve considerenoa of such factors as history of occupational exposures, dyspnea, crepitation*. clubbing of fingers, radiographic signs of pulmonary fibrosis, and abnormal lung function. Certification of asbestoeu tience would occur at sn advanced stage of disease. Each production worker was classified aa having received 0-40 30-90 100-140 130-19* or 200-2*9 f/oc-years of cumulative exposure within the 19 years following initial exposure. Ftnkeisisia calculated incidence rates consisting of number of new cases of cerdfiad aebestosu par 100 person-ysara at riak. (Inodenoe ia the rata at whidi new caaae of aabeetoaie develop in a given period of time. U ia a direct measare of the rish of developing tbs direass.) Inadascs ratsa wars IL3. U and 9J for woriurt who rsceivod 0-40 30-49. and >00-149 f/cc-yseiB respscuvaiy. Flakalatam also --l--l-i--t tha cumuialivs probability of having developed certified aebestosu by tbs and of 32 yeari of latancy. and obaorvad that men in tha 0-49.30-99. and 100-109 f/ec-yaars catsganw had aboel to percent. 33 parent, and 70 p------ probabilities respectively. Dee to small numban of men in each oalaoary. these estimated pndabtiittaa had mech rtatiatical uncariiinty. FinheUtcin stated that the urxertaini-.ea ia expoause aaatgneiaeti and tha aelacnaa teat arising (mas exclusion frem tbs study af worker* with .asa than 13 years of employment may nave lad to overtttiiMtion of risk a: low exposures, which was "o tome extent balanced by tha fact that tha and point we studied wts certified disability, uc advanced stage of asbestosie- (E*. 44-0*4. p. 301). OSHA considers that Flnkeiatain't findings of excess nak (rum low cuaulative exposures art very important because the outcome, certified aabeetoaie. was based upon substantial medical evidence of severe disability from tha disease. Dement and colleagues conducted a detailed study of plant processes and dust control methods st a chrysolite textile plant during 1830-1973 (Ex. 64030 94-017). Exposure histories were constructed for each worker end estimates of individual cumulative exposures ia tana* of f/cc-days ware made. After 19*0 exposure levels usually were in the range of 9-10 f/cc. Workers ware categorised at receiving exposure* of lose than lOOOt lOOO-tOOOOt 10000-40000: *0000-100000! and greater than 100000 f/cc-day*. Because Daamnt at at included holidays and weekends ia their estimate* of f/ccdaya. their estimate* of cumulative exposure are likely to b* overstatad. OSHA calculated that Dement et at e categories of f/cc-days ate roughly equivalent to lass than 2-: 17-27.4: 27.41000c 1000-274: and (teatar than 274 (/ cc-yaare of occupational exposure. holidays tad weekends for their caicolaUae* ef f/ec-days. OSHA divided f/ec-dayt by M to iimt at *tinates of f/oe-ysers. Dement et aL`s drat 3 exposure categories fall within tha rang* of cumulative txpoaures permitted by the current OSHA asbestoe standard. Among whits males with 1? or t years oflatancy. lung cancer SMR's were 140 270 and 3S2 us the categories of lass than 1000. lOOO-iOJJOO and 10000-40000 f/oc-dayt respectively. The latur 2 categories' excesses of lung cancer were statistically significant. For oiber eon-malignant respiratory disease (excluding both infectious rvtptretory diseases and bsonchitisV tha following SMR's were observed for white mala* with 19 or mote year* of latancy: 382 for man with las* tfaan 1000 f/cc-days. 94 for mao with 1000-10000 f/cc-daya. and 979 for man with 10.000 40,000 f/cc-daya. The ercoseal war* statistically significant for both the first and third category ofCumulative exposure. Donat et ai concluded: "Baaed oo data from thia study, significantly elevated mortality risks are pradlctad (or lung cancer end far esbestoaie at cumulative exposures of 100 fibers/ cc x years in tha textile industry- (Ex. 94-087. p. 432V OSHA considers that Dement et ai.'s observation* of <xcau nsx (rum low cumulative exposure* art wellsupported becacsa of tha careful aattmattan of exposure histories for the Hardarsoo and Enttriine (Ex. 04-049) studied the mortality of 1075 asbestos production workers who retired during 1941-1967. Mortality war observed during tha period lMI-1971. Cumulative exposures, sxpressed in millions of particles per cubic foot of sir times yeers exposed (mpcf-ytersV were estimated for each man included in the study cohort. Mean exposures far g cumulative expoeure categories were 92. 192.392.900 end 979 mpef-ysars. Hammad st aL (Ex 94-277} suggestsd mpef to f/cc conversion factor of 1:1.4 for a cement plant. Because cement end other mineral particles have been extetuively used in asbestos product* manufacturing, using a conversion (actor of 1:1.4 does not appear to be unrsasoiubl* far Henderson and Enleriioa's study cohort. Using a factor of 1:1.4.62 mpef-years is roughly equal to 97 f/cc-ytara. A respiratory cancer SMR of 197.9 waa observed in the cumulative expoeure category with mean exposure of 92 mpef-yeara. Thus. OSHA view* this study a* having observed txcaas riak of dying from respiratory cancer among men receiving cumulative exposures permitted by the current OSHA PEL. Using a conversion factor of 13 would result in an estimate of cumulative exposure for tha low axpooara category that ia about 900 higher than that anvisagad by tha current OSHA PEL Dement at ai. commented on the marked differences between the studies of Desnat et aL and Henderson and Entartim with regard to risk observed from low cunraletive exposures (Ex. 44037). Dement at ai. suggested that these difbrancss may be attributable to the fact that Henderson and Enterims studied ratiras* 83 years or older, with these ratiras* constituting saicct group of survivors. Only 0 of tha 33 lung cancer deaths observed by Dement el ai. occurred in poisons 43 or oldar. McDonald. LlddalL Cibb*. Eysaen. and McDonald (Ex. 44-063) studied the mortality of 11J79 workers exposed to chrysotilo mining and milting born during 1991-1990 Mortality waa obaorvad during tha period 1910-1973. Each worker waa cfassifisd aa having accumulated lass than 30. 30-299. or 300 or more mpef-ytar* by (* 43. Using a conversion factor of 1J for mpef to (/cc those groupings would correspond to less than 90 90-499. and 900 or mors f/ cc-ytan. Lung cancer SMR't n-x 93. 119 and 223 far tha 3 categonts starting with Its* than 30 mpef-yaara respectively. SMR'a for pntumoconmsi* wen 290109L and S40C for cumulative exposure categories of ins* than 3a 30399. and300 or mors mpe'-yaarr. H>:nc. McDonald ct al. did not observe much lung cancar riak but did observe an cO S./GSfOOl Federal .Ureter / Vol, 41 No. 215 / Friday. November 4. 1983 / Rule* and Regulation* 51103 nerresr in pneumoconiosis risk in (hi- tow pour category A cate-control analysis used similar exposure categories: however, the analysis was intrinsically incapable of observing an excess nth in the less than 30 mpef-year category because the control* had alto been chrysolite miner* and miller*. Regarding the different Finding* on lung cancer risk from low exposure* between the itudiet by McDonald et al. and Dement et aL pement et aL suggested imprecision of exposure estimate* and difference* in airborne nber characteristics a* possible reasons for the difference*. Dement end Harris previously had found that textile processing produced a higher proportion of long thin fibers falling within the ranges delineated as carcinogenic by the animal studio* of Stsaton and colleagues (See Section E(3) below. Exptnmnual DataI- FinJcaistein (Ex. 14-2401 also studied mortality horn lung cancer, mesothelioma, snd other diseases among workers at an Ontario asbestoa cemtnt factory established in 19*4. The study cohort consisted of 339 men hirod before 1980 who had been employed at the factory for 9 year* or more. Each cohort member waa classified as having accumulated I 88 71M21. or 122-410 tl cc-yesrs of aabestoa expoture within the IS years following initial exposure. These expoture categories, hereafter referred to at Croupe A. B. end C. had the foUow.ngmaaa cumulative exposures respectively 44.91 and 180 V cc-yesrs. Croupe A end B are low exposor* group*. Mortality by cumuiativt exposure was analysed starting 20 year* after initial exposure, to that the calendar period during which death* war* obssirvad spannad 1988-1980. Cohort mortality wee compared to that of Ontario man during 1970-1874 Age-siandardixad mortality rates per 1000 man-years far ipacific causa* of death were computed for Croup* A. B. and C and far Ontario men. Thu*, this study did not have the biases from confoumMng effects of ago that can occur whan SMTs are bang compared aaiong different grange of woriiars (Sea Ex. *4-338). One potential problem is that lung cancer mortality may have risen in Ontario during 19791980c this would result in tome underestimation of comp.innun value* and henca some overestimatiun of lung cancer risk. However, this ovsrestimatioa of risk likely would be slight. Mesothelioma mortality Mtcs per '.000 nsn years for Croup* A. 0. .ir.d C iverr 4.9. and ll.Sresnectui lv. lamp cancu mortality rates prr us*) nun- vrjrt Here 13.8.28-1.11 9. sod 1 8 for Croups A. 0. and C and for Ontario men respectively. Approxima:* relaiiva risks Tor Croups A. a and C as compared to Ontario men. arc 8-5.183. and 7.4 for lung cancer mortality. Casiromtastinai cancer mortality waa also slsvated ut Croups 0 and C relative to Ontario men. The lung cancer mortality rata* did not consistently increase with increasing estimate* of cumulative exposure in that Croup C had the lowest lung cancer execs* Finkelitein suggested several potential explanations. including inaccuracy of expoeura classifications, statistical fluctuations resulting from the small six* of ths cohorts and confounding effects of smoking if there were differences in smoking habits among Croup* A. 8. and C Bacaus* a consistent dote-response was observed both for mesothelioma mortality and asbeaiotis in the study group. Finkalatata suggested that th* exposure daisificationt may hev* been correct. Flnkelatein concluded that lung cancer mortality rata* "may be raised severeifold" (Ex. 84-240. p. 143) it cumulative expoeura* of 100 f/ec-y*er*. With regard to gastrointestinal cancar. Finkalstain judged that no firm conclusions could be drawn dua to th* small number of death*, although (her* wet a trend of increasing nek with inenattng cumulative exposure. Mesothelioma death rata* war* considered by Finkeistetn to be related to cumulative expoeura. 09HA believes that Finkslstttn't study presents avtdenc* of excess lung''" cancar and mesothelioma ntk from relatively low cumulative exposures, namely 44 and 92 f/cc-yt*rt. Lung cancar risk may hava bean somewhat understated by Finkalatsm s exclusion of lung cancar deithe which occurred before 20 yean of Follow-up. Rubino. Plolatto. Nswhoua*. Scansetti. Arasini. and Murray (Ex. 84-43881 studied th* mortality of 932 male Italian chrytotile miners and millers during 1948-1879. Mortality (ram respiratory disease and other causes of death, but not from lung cancer, was excessive in this cohort. Criteria for inclusion in tha study cohort ware survival until lanuary 1.1948 and at least on* month of employment during 1930-1985. Comparison of mortality was mad* to ace. calendar psnod. ana cause-specific mortality rates of Italian male*. In addition, mortality rata* war* compared among th* cohort members using a case- cumrol analysis and a historical prospective analysis. The cumulative Flic* exoosure was estimated (or each wnraer in trims of f/ce-t ear*. The investigators simulated past working conditions and measured dust concentrations during these simulations in order to make more accurate estimate* of exposure during periods |pre-19C9| in w hich exposures were not measured. Mean concentrations of ajlicsios were estimated to range u|i to 50 f/cc before 1950. Compared to Italian males, the overall cohurt had statistically significant excesses of mortality from laryngeal cancar. non-malignant respiratory diseases, tuberculosis, cardiovascular diseases, cirrhosis of Ih* liver, and accidents. Lung cancer mortality was leveled only slightly (SMR-1081: however, there was some trend of increasing lung cancar risk with increasing length of follow-up. For example, the SMR for lung esnesr was 208 during 1971-1975. Because all analyses of mortality in relation to cumulative exposure consisted of comparisons among tha cohort members, rather than between tha venous exposure subgroups and Italian mala*, these analyses were incapable of dittoing exeat* ritk in the lowest cumulative exposure category. These analyses were capable only of detecting trends toward increased ntk with increased expoture- Although the excaas lung cancar risk (odds ratios 289) in tha high exposure group was not statistically significant. Rubino et aL considered it 'likely that th* increasing mortality truly reflects ths effects of higher exposure" (Ex. 84-088 - - p. 193|. (Th* odds ratio is in ssttmats o^ the relative risk defined as the ratio of the odds of dying from cancer irr the t exposed population to tha odds of dying0 from cancer in an unexposed 3 population.) ^ Rubino et aL's study is unusual in nci c.n finding a higher lung cancer risk among to worker* exposed to relatively high levels of asbestos. OSHA believes-Wat the trends of increasing lung canctr ntk with both incnesing length of follow-up and increasing exposure are consistent with an aabestoa etiology, however. OSHA alao believe* that ths high risks of mortality from othar causes such ss non-malignant respiratory disease might have obecured lung cancar risk, atpodally one* the** high naka appeared within tha first 19 year* following exposure and aabastos-rtlated lung cancor generally has a longer latency period. Also. OSHA calculated that this study only had 333% power to detect a 50% increase in lung cancar nsk among workers with 20 or more ytars of follow-up. Seta --Siahsiical power quantifiti ike abthix of study to detect a tret trcrtiKd r.tk f a spectfiad magnitude and rsltrs to id* / SI 104 Federal Rafjptar / Vol. 44. No. 21S / Friday. November 4. 1083 / Rule* and Regulation* probability of Mt *!* Me m*. CaiMraUy. U is ecapidifad Qaairpbli (pr tedwe w have p< taMMS power. Because ptoappMagw ptadlm shoald hev* pi Ipppi IK power M detect a MS laaepae Im riik p| tang caocw. Sea to. 4P-tM Swat oiOSKA'smath WoiH Hughes and Wagganapack (Ex. II IBS)tavastigtaad axpowo-raponat relationship* botwoan raapiratory cancer M and aapoaura in an asbaatoa cament plant Weill at aL did sal obaanre oxcvm rt*k among man with low cumulative axpoauraa. A Intel of S.MS man with at toast 90 year* of latency tinea flint eapoonre in either of 2 aabeatop catnanl plant* ware ttadied. All men had at toaat ana menth ad employment before 18PB and that/ vital atatoa era* determined pi ad December It. 1474. Each worker's caamladv* duat pxpoaur* dtatag the 20 year* ham initial exposure waa eathnatad in tans* ad mpef-yaan. Men erare dastifled tn ana of S different cumulative aapoaura' eatogottoo! 10 or fewer. 11-801 S1-10Q, 101-200. end 200 or mate mped-yaats living the canvaiaian factor ad 114 suggested by Ha--ad at aL the I cumulative aapoaura raiagnrie* araatd be equivalent la 14 or borar. 1S-70.7114a 141-Zia and 2*1 or mora f/cc-yean. Raapiratory canear Mi omm u follows starting with the loweat category: I7.AA 2KL and 22a. Nona odiha other caaaaa ad death were in ` rucem for wortara in the 1 loweat categories Coocarmng thalr failure ta detect txcaa* raapiratory canear mortality in thatr loweat categories od axpoataa. W*iU at aL plates "Sadi finding* tie rot nacaaaanly incompatible with Lineor reopooao cotve at low deem bacaupe od the futatie* tnaansiUvtty od currently eaad apideminlngte method* ta dotoctisg slight tncraoaaa hi itah whan cotnparndtnl indicate, however, that t at law dagrooa ad i (Ex. 44-201 p. 30). issra.WeiU et aL ootad that to miatt high proportien (2M) M I were ioat a feflaw.o and aaaamaS live through 1474 may have lad la undsnsrims torn ad raapiratory cancer r.sk. The upper Barite od the 44S confidence intervala ad the reeptratory cancer SMR'i for tho 9 Inereet rxpooun catagorim rasped bom about ns to U& Indicating, in OffHA'a opinion. that axcaaa riak could not be ruled eat for theta categories Barry and Nawheuaa (Ex. 44-on) studied martaiity during 1441-1474 of a cohort of friction malarial production worker* whoa# axpoaum war* relatively law. Lavela of axpaaara ranged from toaa than 1 f/cc to I f/ee after 1431. and cumuialiva axpoauraa far the cohort averaged lea* thaa SO f/ ytera. Although excaaaiva mortality tram mooothoUoma waa obtarvad. there ' ta be little excam mortality r. Moat of the _________ _ jm ^ bMS WpOMd to aabeatoe lavela oxraodlng I f/ce. The cumulative axpaeure* ta asooato* of tb* maaathaliema caaaa ware not rapetiad by the author*. Unexpectedly, date study ebmrvad scanty* mmelhaHama a>oruHty bat only a noa rtmiiflcanf axcam ad lung caaear mortality. A aiaabie pertiea of tha ptudy cohort bad a abort follow-up parted between thalr Initial axpoaaia and tho ttady cot-off dais Far axampis 3311 of the amn had follew-ap parted* of tea* than 20 years Lung cancer risk may b* expected to tncraaa* in this cohort a* tha awmbat* are followed far a longm X Summary. A number od epidemiologic ttadim have examined pxpoaur* raapenaa ralationphipa far aabaataa and sobeatoa-reiatad dlraaaas OSHA racogniza* that thara are many taavtlabt* ancartaintim aaaadatad with epidemiologic ptudlaa ed expeaura- reppopiaa. Rarely. If over, ar* pereaaai sample* of aabaataa concentration* for pxpoaed worker* during tha entire period of expeaura avallabis Inveatipatote typically have davaleped individual I ' recant tnduatiiul bygtana dats G--OBiBi.6 tbont paat worttiag for which oxpoeuree meamirad. Another qaaatian concern* tha factaca for convareion from historical method* ad maaaatag duat concentration* to current method* ed ratio of aitlFons of pertictoa per cubic foot (mped) ta fiben per cubic centiawter Wac) him bean suggested aa taagiag nnm Id to 13. Cooverptoa (actor* ad 13 far mp^ f/cc in aabaataa mining and ^ ` 114 fa* aabaem* production to OSHA. OSHA elaa tha atattatioal variation aaaadatad with aatimattaa ed SMndaidtad Mortality Ratiaa (SMR'a). Sneh (Uttatteal variation, aa well m dlffaranma hi study daaigs atattatieri power, and length of follow-op. may occaunt for tarn* of tha divergent i tha present OSHA PEL of 2 f/ cc oraa afbctfvt ta 1471 than mo few. tf any. ocaupaticnal cohort* sitpmsd solely ta 2 f/cc ar lam who hav* follow up tatarvai* sufficient far tha ppoaraaca of ditaaiaa railtad to bettor axpaauro. At present. OSHA Ii not pwpip of any evidence suggesting that mttnaity of pxpoaur* wtllaiTact scam riak ta a manner different from cumulative exposure'. which encamp***** both deration of axpoaur* aad tasanaity ad expeaura. Moat rpidamiologtc studio* have obaarvad tacraaatag riak eHth Incraaatag cumuiptfv* axpaaors Duration at xpoaure auy have aa independent affect an maaothaliama riak (aaa Section V. Quantitative Riak Analysis). A workm axpoaad to tha OSHA PEL of 2 f/ee for yean would hav* a cumulative txpaaura of 100 f/cc-ysarm. Hanes ptudiaa of warkar* aatimatad ta hav* racatvad data to or lorn thaa 100 U cc-y*ar* provide evidence canearning riak bom axpaaara ta tha OSHA standard. avan though tha paat intaspitia* of axpaeure may hav* axetodad Z f/cc. OSHA mnatdara that tha following ituditt hav* obaarvad taoaaaad riak dam to or below 100 f/ec-yaars Barry at aL (Ex. 44-020) obspnrpd a I* prevslanc* ad oapitatiaas poaaibfo lahaatosts aad ctrtillad aaoaateata at 37.4& and 41 f/ee-yaara raapoctivaly among aabaataa textile workers FlnkaiPtata (Ex. *4-044) obaarvad a 10* probability of havtna certified psbmtaaia among asooato* camant production ararkara with comulativ* xpanirm od lam than SO f/cc-yaara who had boon obaarvad 22 yean rinca their taMal axpoaaros Ftakdatata (Ex. M240) alaa obaarvad axeaaaiva lung cancer martaiity aoMOg ararkara with avara** cumulative axpoauraa of 44 and Sf/cc-yaars Among aabaataa taxtila workers Damant at at. (Ex. *4-038) obaarvad excessive mortality from lung cancer aad nan-malignant raapiratory dimaao* at cuamiattv* axpoauraa of lam than 1000 f/eo-day* and 1000-10000 f/ocday* (aqttivulant ta lam than 2-7 and 17-274 f/eo-yoata). Handarecn aad Enttritaa (lx. 04-040) obaarvad about a 2-fald l~------ ta lung canear mortality ambit** axpaaara ad 42 mptf-yaan (agtavabal to 47 f/co-years using a amraraian factor ad VIA). At rtlatfvdy law cumulative . the following itudlas did net m hag cancer riak or oaaarvod only a small tnaaas* tat lung caacm nak. Barry and Nawhouaa (Ex. M (IB) obssnrsa Unfa axcam lung cancer mortality amang friction malarial pnductian worker* whoa* cumulttiva xpooura* avtngad lam than SO f/ccyarns Mppothaltoinp case* wvr* obaarvad by Barry aad Newhouaa: STOO'159^7 Federal RFgiifT / Vol. <a. No. 113 / Friday. N'ovemlmr 4. 1963 / Rule* and Regulation* 51103 however, their cumulative exposure* Francisco and Oakland (Kanarek el aLL were not reported. Weill *t *L (Ex. ga while other atudiea did not observe a in) did not find increased mortality relationship between asbestos 1a from any eaoao of death below in dunking water and canenr incidence mpcfyears (eqeireleat to 141 f/cc-yeert (Harrington at aL Mtigs at aL Levy at ueing a coaveritoa factor of 1:1.4| in a ai| (Kang. Ex. 90-139). OSHA is aware cohort of asbestos cement worhara. that ecological stadias generally have Rubino at aL (Ex 94-099) obsarvod only cartaia limitations for determining tha a (light excess of baa cancer mortality afflicts of long tana anvbonwennl (and a large eeceee qf BMrtality from axpoaura to apactfflc subatancea. other eaaaaa. aaek a* itotHnallgnam including confounding variables such as respiratory diaeaee) da*pita high migration into and from communiiiea expoaare level*. Data were not analyxad and mulUpia axpoauras to other by Rubino at aL la each a way aa to carcinogens and toxic chemicals. For permit eetimatiea of risk from low sample, increased caacar mortality la a cumulate* npoimi particular community may result bom McDonald at aL (Ex #4-003) obaarvad occupational axposuns rathar thaa from little or no eaaaaa lung cancer mortality carcinogens in tha drinking watar or among aabaatoa atinan and milter* ambient air. Bacause atudiaa of receiving law caamladva sxposurnx occupational cohorts do not have cc Eacaaa mortality from pneumoconiosis many limitations as ecological atudiaa. waa obaervad la ha low exposure occupational stadias have the potential group, however. Worhara receiving leaa to bo mors determinative concerning than JO mpcf-yaan by age 41 had aa caronoganic risk to humans, depending SMR o( aa hr pomamoconioaia (30 on soa of tha cohort langth of mpcf-year* equals 90 f/cc-yeare uaiag a observation of tha cohort and othar cooveraioa factor of Id). pertinent factors. Therefore, because Aa la commonly obeemrod among well-conducted epidemiologic studies of epidamiolagc stadias of atiotogic aganta asbestos worhara ara available and for dieaaaa. there are eome because inhalation rathar than ingestion mcottaiatandea ia the Hading* of ia the primary roam of workpiece dtlferent atudiaa of worhara accumalatiag relatively low aapoaurea. axpoaura. OSHA has based its QQ ^ Statistical variation. dlflaiencae in the caroaogemctty of aabaatoa for sites tixa dlstributton of airboma Oban, othar than tha lung and omaothalium on tmprocirioa of expoaure eatlmatea. and epidemiologic atudiaa of aabaatoa compatitian among dtfhraot eaaaaa of worhara. 2. SpjdoauologyStudioo. Flaws and incosutem^n. NoMthttaM* OSHA Simpaan studied the mortality of Belfast considet* that away wtll-eonductad insulators employed during 19*01 mostly atudiaa abaarrad rabataatUlly increased la shipyards (UTL 1997) (Exhlhfu 90- hah of death from lung cancer and oon- 041 and 94-042). Vital status was malignaat reapiretcry diaaaae among observed during tha period 1940-1973. workera receiving cumulative eapoaaraa Excoti mortality waa obaervad bom permitted by the current OSHA asbmtosix lung cancar. mesothelioma, standard. OSHA condudea that theee and gaatrowtastinal cancan (stomach, study results provide evidence of grave jefunum. pancreas, colon and rectum(. danger bom low cumulative exposures Dmaa and Simpson staiad that `both to aabaatox ia respiratory and ia gastrointestinal C Carcirofwnidty ofAtbrtUM for Siloo Other Than the Lung end Meeofhe/iiim cancan than is tha difficulty of diffamtmtiag between maaothellal and epithelial tumoun* (Ex. 94-042. p. 171). 1. Jnfodvctum. A number of studies of Of tha total 122 deaths W this cohort. asbestos worhara havo obsorvad ' either autopay information or ciinlrai excesses of caaear at attaa atbar thaa information with biopsies and/or ths lung and mssnthslium Tbaao atlas inciuds colon and rectum, esophagus, radiographs aupplanwnwd tha death eartificama for ail but 21 deaths. By stomach, larynx, pharynx, buccal cavity, i9Mi u daatha bad baoa eodad as kidneys, and ovarian. Baaad on thaaa siuoies. OSIIA has concluded that gastrointestinal cancan on death certifiestax 12 of which continued to bo gastrointestinal maligaanciaa appear to have bean produced by aebaatoe inhaled in the workplace. classified aa gaauoinmstiaai cancan abar supplamantal Information had boms obtained Using tha axoactad value of A variety of cemmuatty-baaad L18 deaths for all oca nspintory epidemiology atudiaa have Invaatigatad . cancan that ware nported by Bams tha effects of ingestion of asbestos ia and Simpson. OSHA calculated that tha drinking water. One study suggested gusirtMoietunal cancar excess waa that asbestos in .tanking water statistically significant at tha 04B level ncre.ised cancer incidence >a Sun (one-tailed Poisson test). Ernes and Simpson concluded in their 1971 paper "Cancar of tha lung and mesotheliomas do not account for all the txcess of deaths: a significant excess of othar cancan remain. . . and moat of thaaa appear to bo in dm gastrointestinal tram" (Ex *4-041. p. 239). la their 1977 papar. Etama and Simpson rvpor;J a decline in both aibaatocis and gaatrohuaatiaal cancar as mater cause* of mortality among dm survivors followrd from 1967-1973. Selikoff. Hammond, and Seidman studied a cohort of 17.800 U4L and Canadian insulation worien (Ex 84080). Comparison of insulators' mortality during 1967-1978 waa made to aga and calendar period-specific mortality rates of U.S. whim malax Tha large six* of this cohort resulted in vary high statiatical power to dalact increased mortality bom specific causes. . Thareforx OSHA considers that this study curias much weight with regard to tha question of aabestoa-inducod malignancies. The investigators sought supplemental dinicaL surgical, and autopsy information in order to dawrmiim tha axtant of miSclasaiflcation of cancan. Baaad on daath cardficam information alone. significant axcesa mortality waa obaarvad bom lung cancar (SMR-400I. mesothelioma (104 deaths), esophageal cancar (SMR-233). stomach cancer (SMR-139L cofon-racml cancar (SMRw 132). laryngeal caacar (SMR-tflL pharyngeal and buccal cavity cancar (SMR--130). kidney cancer (SMS--223). all othar cancan (SMR-191). and nan-infoctious' rtspuawry diseases (SMR-319). including 79 daatha bom asbestosis. With tha sxcapnon of daatha listad as "all othar cancan", reclassification of daatha baaad on aupplamantal dinicaL autopsy, and surgtcaLdata resulted in slightly higher SMR'l for the causes of daath liawd abovx OSHA botiavas that Selikoff at aj.'a radaaaification of cauaos of daath ta jualifiable becauaa misdiagnoais of mesothelioma and aabeatosia can occur due to these condition*' resemblance to more common disestex Furthermore, it ia possible that mamataaaa from primary lung cancan could be misalignosad as primary cancan of other sites, and vicevanx One disadvantage of ncUssificatioa of deatnx however, is that urn axtant of misclaaiification m the cmnpartaoo population of U S. whim males remains uikaown. Nonetheless. OSHA Mliavaa that for this particular cohort, tha advantaga of ndasuficition ia ttrms of improving tha canamty abo'it tha uusaa cf daath outwtighs ilia disadvantage. ! ST00U5978 1 1106 Federal Resides'/ Vol 46. No. m / Friday. November 4, 1983 / Rulesand Regulations In iha category H*ld "aB e(her rancers." 233 deaths were oboorved compared ta tSl4 deaths sspiciedL The iiou in ihia category waa mostly doe to increesed mortality {rota pancreatic cancar |SMR2St|.lieor and biliary tract cancar (SMR-2SSL preatala cancer (SMR 137). and brain caacar (SMR-I63L Whan radardfhd according to supplemental information, the panavutic cancar aacaoa dadinad graally and tha liver and biliary tract cancar tuna disappeared. SelikofL Hammond, and Seidmaa concluded: "Aaboswa inaalalioa workers in the United Stalea and Canada sulTer an extraordinary increased riak of death of cancar and asbeatoeis associated with their employment. This indadoa Incroasea in death from lung epneer. ploaral mesothelioma, peritoneal eioaotheHnma. caacar of tha aaophagaa. colon and ractua. cancar of the laryaa. oro pharynx. Kidney, and perhaps stomach. Soma increases were seen in cancar of several other sites, as well, but data are inadequate at this tuns to permit characterisation of their aiguAcaaca. although attention la called to such widsr increase" (Ex. M <B0,114). Dement and cwUeguta (Ex. BB-037) observed a statistically noo-sipufictat incroasa In digestive caacar mortality (SMK--tJl). Whan Dement at oL confined their anelysia to white males with latency tntarreis of IS or mars years and axaodnad svpneura rasponaa itiattoneMpa for digestive system cancar. SMR's Incroaaad with Inaeaatng cumulative exposure, ringing up to JgQ. Because of the small numbote of deaths, none of the excesaot of digestive caacar in any of the txpoouru categories wore statistically significant. McDonald and colleagues (Ex. M-OBS) observed soma Increases (not statistically siprificaat) in mortality from esophageal and siimiath caacar and from colorectal chrysolite miners and miltan te Quebec. with hoavtor cumulative ospoaurus. Seidman. Selikog. tad Hnmnmnd (Ex. M QgT) stediad a cohort of MB tmodte insulation production worfcan amploysd at a Now Jersey plant during 1441-1S4&. A statistically non-significant oacaaa of stomach. and eoiois-eactual waa observed (SMR--121). Htedarson and Enieriine (Ex. SB-Ott) stediad tha mortality during iBtt-IWSof 1MB rvired asbestos factory worker*. Fiftyfit s deaths tram digestive oystom rancor wera ohsarved compared to 3BJ doatha e-pocted .Shi*-1174) (OSHA c.-i!culatod :hal this excess waa staiistically significant at <ha 043 leva). using a one-tailed Poisson tost). Nicholson. SelikofT. Seidman. and llammoad (Ex. BB-231) also stedied o cohort of US. asbestos factory workers and abssrvsd statistically non significant 14-fold oxosm of gestrointcslinaj cancar. Newhouao and Cviiy 0bk St-310) oboorved a gastrointestinal cancer SMR of 11B in s cohort of London asbestos factory workare (BO deaths ohsarved versus 444 oxpoctod) (OSHA calculated that this excess woo statistically significant at tho (LOB lovoi usmg a ooe-tmiled Foisaan test). Puntoni et sL (Ex. SB-MS) studied the morteUty of shipyard workers exposed te asbestos in Canon. Italy. TVno workers were elan exposed ta other toxic substances, including siben. bensonn. carbon tsoochhiridoi nod poiycydic aroauOc hydrocarbons. Compared to the ego specific morteUty raise of mate Canoans. (ha shipyard workers hod statistically significant incronsoa in mortality bum colon cancer (relative risk-1411. All of the stedleo listed tat this paragraph also oboonrod txcoooivo mortality hem hmg cancer. la addition, other investigators have observed txetsaos of digestive tytom cancar. Robhuen ot oL (Ex. IBOSS) observed on SMR for digestive system conrer of in (not s statistically significant excass) among asbestos production workers. Kteinteld et aL (Ex SB-14& SB-141) obaarvnd an SMR of 400 (staaattctUy significant) Cor digoottve tysf emon among trsmsllts and inthopbyUlto sxpusod workers mating tele. Msnceso sad Coulter (Ex. SB-ZM) also shotted a siptillcantiy elevated dlgtetivu system cancar SMR among Insulation workers. Flakelateia observed a statistically non-significant 2-fbid Increase in mortality from digestive system cancor among asbestos cement workers (Ex. SB-JSO). A number of studies have nor observed ssccesstve gastrointestinal cancar mortality among workers expoosd te asbestos. Nicholson SeUkoS. Seidman. LOte. and Fonaby (Es. SB-071% who stediad the morality of S44 chrysotila miners sad suiters bom Qusbec. abssrvsd a gaatrotwtestinnl caacar SMR of only '.OS. WsOL Hugnea. and Wagganspack (Ex. SB-MS). who stediad a cohort of S44S asbestos comont production workers, also did ant observe on excess of deaihs from gastromlssUaaJ runcer. Other iavostigators wnodid not obsorva an tnaeaaa m gnstrointMtiiui cancer mortality techuls Bony and Newhouaa (friction materials production workers). Kubino at ai (chrysrtite miners). Meunnan at aL (.inthophylUta miners).. Brown <*t aL (tale workers rxposrd w asbestos). Weiss Ichrysotila factory workers). McDonald and McDonald (asbestos gas mask workers). Ptto ot aL (asbestos textile workers). Thomas ot sL (asbestos content workers). Koasilcr am. Coles (shipyard workers), and loots at aL (asbtstoe gas mask workers) (Ex. BO WL Whan non-gaairolntesilnal canon at sites othor than tho hing sad mosothoUum on considered. at load 4 studies oboorvod excesses at these other tiles: Selikoffet aL Sbettigsra and Monan. Puntottl at aL and Stall and McGUL Other studies havs not observed excesses of cancan ot othor sites. One issue which the Agency hod to address was bow ta weigh tho poailivs tpidemioiogsc data versus the nonpositive epidemiologic data. One consideration la statistical power, tho ability to doted a mo risk if such a riak exists. Tha Chronic Hoxord Advisory Panel on Aabootoo (CHAP) convened by tho UA. Consumer Product Safety Commission did not find o consistent relationship between having s higher degree of statistical power end finding excessive mortality from theta othor cancan (Ex. SB-2ML It should bo noted that tho study (hat had tho highod statistical power by virtue of studying 17400 workers, namely that ef Sshkaff gastromtaetiaai laryngeal kidney, and rhsryugssl and buccal cavity cancer. A aether cnnetileretion is the ratetlnaship bsriessn tho magnitude of excess long caacar.riak and excess gastrointestinal caacar risk. CHAP observed that stadias with high lung caacar evresets wan aiao likely to have found gastrointestinal caacar cxcessaa. Because high lung cancer risks would be expected to hove resulted Cram relatively high exposures. this observation suggests that sasowatesUnal cancar excesses an found whan tspoauna an greeter, which inaeaaea the plausibility of than being a true association between asbestos and gastrointestinal cancar. In summary, d land 13 different occupational cohort! reposed te gastrointestinal cancar. 7 of which won statistically sipilfiront OSHA considers that then findings conatitots substantial evidence for an association between asbodoo exposure end |tstraiatostinal concur risk. The evidence hr a relationship between aabaatoe exposure srd caacar at other sttes la noteworthy "yet not oa substantial as that regarding gastrointestinal cancar. Goldsmith (Ex. >4-133) reviswed the evidence hr a causal relationship between asbestos exposurt snd non- 1 s 7 0 0 'J59 9 rodoral Rdgistor / VoL 4& No. as / Friday. November 4, 1983 / Rule* and Refute Horn 51107 pulmonary cancer in studio* of 11 occupational cabana followed for at leasi 20 year* lince initial eipoaura. Ha concluded tltai tho data 'cast doubt on whethar there ta atlt apedficity of aabeatoa-felated cancer" and that 'a systemic carcinogenic rate ia am likolv (for aabaatoap (Ex. 84-231 pp. 148-347). 1 Toxicology Siudiot. A somber of toxicology atadiaa have been conducted to determine tha earanogaitieity of infeated asbestos. Inhaled asbestos la thought to enier tha digeative tract whan aabeatoa fiber* caught in tha mticoua lining of the lung are brought up to tha throat and ewadowad. Also. libera caught in tha noaa may travel down to the pharynx (Kang. Ex. 04-1nj. Evana at L (Ex. 00-2301 conducted an inhalation itudy ia rata of radio-UboUed croadollte. The radio-labelled croadoiila travaiad to tha larynx, eaophagua. and gastrointestinal trad immediately after expoaure. and waa largely excreted la the facts within the JO daya following inhalation. Tha National Toxicology Program (NTP) haa adminiatarad chrysotito. amoaita. tramolita. and oocidoiile in feed (1% of diet) to laboratory animate. Increaaed inddencaa of turnon have not bean reported in any of tha NTP atudiea (Exhibits 04-221.04-220.00-222.00-220). In aome of tha studies, relatively short fibera were administered. Tha aabeatoa doee of 1* ia diet waa not the maximally tnlaraaad doee (MTDV unlike meat rairinnganeela bloaasay*. Ward. Prank. Wank. Davor, and Tarone (Ex. 00- tC0| examinad tha effect of oral expoaure to amoaita or chryaottto on gaatroiataatiiiai (Cl) rareinepanaaia among P300 rots who had baea inlactad with axoxytnathana. Axoxymadtana ia a weil-racagmzad intestinal carcinogen tor laboratory animola Rats wars also exposed ta amoaita alone end aioxymathaae alone. The aappears period woo 10 weeks and tha rota were observed for M waaha or more (nna rata did not sarvtra aa long ae to weeks). Although aanoaila end chtyooMlo expoaure did not stgydflrsntiy lacreoeo tha incidanoa of <3 oancnr among rota given axoxymethano ln)octlona. tha 00 rata receiving smooffa aiona had aa unusually high Incidence (32%) of coton carcinoma cnmpifad to din incidance among kiatoncai coptroi 7*44 rats mairtuinod in tha sama laboratory. Ward at ai. commonttd on these findings: "The reaelta of thaao experiments surest that oral asbestos nxpasurt may have caused an increased incidrnce of intastinoi tumors in mala F344 rata .. Although our finding* did rui cnnriuaissly demonstruts tho eo- tarrinngmic or carcinogenic effect of for the intestinal tract, our results suggest that additional sensitive animal experimanta art nerdad" (Ex. *4-20& p. 31U Bolton. Davit, and Lamb (Ex. 04-214) odminiatatad amoaita. eroeidolit*. and chryaotilo in diet supplements to Wlstor rota for periods of up to 29 months. Malignant tumors, including Q tumors, wen not massted in the ssbestoe- xpotod animal* compared to tha oontrait: however. chrytottUMrested rat* had statistically significant excaaa of benign tumor*. Tha txceai of benign tumor* in chryaotila-trastsd rat* waa largely due to aa excaaa of mesontaric hemangiomas. Bolton at aL thought (hot tho observed excess of benign tumor* in chrysotile-tieated animals waa not likely to be due to asbestos because they did oot observe asbestos fibera ia tho meaenltrtc lymphatic btsuea of tho animals. Donham. Barg. WUL and Ltininger (Ex. 84-7T7) fad F344 rata a dial coaststing of 10* chrysolite. A total of 100 atbaatoe-fed rata sad 312 control rats were studied. Regarding their findings. Donham *t aL stated: "Although tho risk differences far dovelopmeot of coion tumors specifically ia not statiitlcaily significant at tho 9% level wo feel there ia simnsilrs evidence that ingested asbestos asay have tome rate ia colon carataagonaHa.. .* (Be. 84-222. p. 1000). Smith. Hubert Sobol Peters, and Doorflar (Ex. 04-103) administered amoaita aahoatao ia drinking water to Syriasrhamatars of the Laic LVG strata far periods ranging op to 22 months. Than was toaw austera. of malignant tumors, indediog a peritensoi tneaotheiioma. a pulmonary carenmna. and 2 squamous call cudsomaa of tho fortetomech. ia the hamsters exposed lo smosite (4 of 100 anunals). Nona of tho comrel sounels developed theeo typoe of malignant turnon. Smith si al did not rtmsiikr the duatenng of ouJignaat tumor* in amoaita-expoMd --*u to bo feiatad ta their ingastioa of smoeile bocaueo those type* of tumors hove boon observed in control Syrian bamstars of tho Laic LVC strain by other tovoaiigatats. OSHA eenaidan that there it tome evidence that oral ingestion of asbestos it carcinogenic to laboratory animals: however, this evidence is rather inconsistent. The generalixabiUty of tho ova-postlive NTP stcoirn is somewhat limited by tho lew dose* and short fibon that wen admmistvred to tho animals. 4. Summon. In summary, at least 12 aptdrmimec-c studies have observed increased atottallly bom gastrointestinal cancan <irony workers exptsed to asbestos. ~ of which were staliMicjUv significant Also, at least 4 epidemiologic studlee have observed exceasee of cancer at tries other than lb* respiratory tract meaothelium. end laalroinlealinal trad a number of other ttudin have not observed increases in mortality from cancan at sues other ikon tho king and meaothelium. ft is possible fer physicians to misdiagnose peritoneal mesothelioma at gastrointestinal or other cancrrr however, the excess of gttirotntsstinal cancer persisted even abar Elmss and Simpeon and Sellhoff tt al. reels isified cauoaa of death using supplemental autopay. surgical and clinical information. OSHA belisvst that the results of those reclassifications constitute additional evidence for an association between asbestos exposure sod development of gastrainiesnnal cancer. OSHA raggrda tho numerous epidemiologic studies indicating increased hah from gastrointestinal canrar as outweighing non-positive epidemiologic studieo and non-positive and equivocal finding* to animal* ingesting asbestos. Does response relationships for gastrointestinal cancer are choractertaed leas well than far raspiratosy system cancan. Nonodtotoas. OSHA concludes that gastrointestinal malignancies should be included to quantitative analyse* of excess caaear risk from asbestos exposure boceeee such cancers have mode substantial contributions to tho increased mortality of many cohorts of sshe*me workers. Otherwise, excess _ cancer risk from aaboetoo exposure LO would bo understated. --4 The excesses of malignancies at titeaCD other than the long, meaothelium. end <--i gastrotntastinal tract obaerved by Seiihoff et al are particularly noteworthy because of the large size o Seiiltoff etaL's cohort. Tha targe size o their cohort remilted to e high degree of03 atottotienl power end a high degree of C3 stability tor tho oboorvsd SMR's. OSHA considare that asbestos might indue* cancer at site* other than tha lung, meeothallam. and gastrointestinal tract based on tho studies finding cancer sacoasoa at these other site*, especially the study of SoUkoff et aL OSHA will not attempt to quantify tho excess risk at these other sits* in teiation to exposera. OSHA view* tha evidence for asbestos inducing gastrointestinal tract caaear as straagar and toon consistent than tho evidence far asbestos inducing cancer at `Jwso other site*. D. Effect* a* Cigornt* Smoking '..Introduction. A multiplicative affect of asbestos exposure and cigaratta smoking with regard to producing 51108 Federal Register / Vo!. 40. No. 215 / Fri!jy. November 4. 1983 / Rules ami Regulations increased lung cancer rial was show* in a IMS paper by SdiUt Chuff, and Hammond (Ex. I-l). Subsequently. other undies of occupational cohorts confirmed this finding (Seilkott Sctdmea. and Hammond. Ex. M-ttt Haaunond. Seiikoff. and SaMmaiv Ex M-047). Cohan el si. (Ex *4-01) observed poorer particle clearance from the lunge of smokera than from the hmga of non-smokers. This finding stay help to explain the higher lung cancer risk of moling asbestos workers. In addition, moling asbestos weaken have been reported la be at higher rial af asbestos** end cheat X-ray abnormalities. Inchiding pienml plaques (Hammond el aL. Ex SO-MT: Weiss. Ex. SI oar. Weisa. levin and Goodman. Ex sa-OSSl There is no evidence hr an association between operetta smoking and either msseihslieme risk ar gsstrotntosdnai cancer risk [Hammond etsLExSMMT). t Ratpmiory Cancer Hammond at *1 (Ex SS OS7) eolloctad smoking histories hem S2 of the tan insulatlan weaken with a follow sp period of 30 or amn yean since initial exposure who had bean studied by Seiikoff and colleagiiee The mertsllty experience of these woriten wee obeerred daring 1M7-M7k Of the SZ30 workers who answered the qvMtionMtfii oi iaokta| HtV^r to lid USX seal were itthsr cwrent orpesl cigeretta emeken. SS had a history of pipe or cigar smoking, and SSI had never sseohed regnlariy. The comparison popelatton was drawn from the Aatariran xaneer Soriety's long-tom prospect*vs ephmratologic stedy conducive by volunteers, and rmnaietad of 7X7*3 whits men who had no mar* Uteri a high school education, were net farmers, were alive as of loaeary L liar, and had a history of occnpedonoi rxoosere to deal foams, nwpon. gasox chrisucalx or rsitistton The mafar advanugs of this compariaon popolaiioc was the ivoflabfllly of agespacific mortality mtao by smoking stotox Also, assn with the abmra itoaihid itoflitoiltoacaMtidiil histories likety weeid mssobis tbs insulation workers man than tbs peosrsl Ui whits moio popoistiax Age-standardised long cacern mortality rates for centreIs and (or asbestos wurkera are given in Table X As show* to Table X eon-smoking asbestos workers bod a mortality ram from lung cancer that was 5 times higher than that of non-smoking controls. The lung cancer mortality of smoking aebeetov ~rfc*ra wee elan S times higher then the controls with a history of cigarette smoking. Thus, for both smoking and non-smoking ssbestos workers, the relative nsk of death from lung cancer wee about S-foid. Hence, the rclutionjhip between ctgar*<to smukuig and asbaeloe exposure can best be described aa multiplicative In nature. Tmle I e*-}ttn*ar*iie* heg Cancer beau ftetee ey Semiag Kates me Cccuesttsasi Hitter/ sf assesses tapesere hrSup e Cantrell tontii imn tipsters ta nmesusT OS res History *f Cigsrstt* Sewmgf he m Oatte Mtt* Msrtsllty Oiffsrence Here*tit/ it tie 11.1 11.1 0.0 S7.I 1.00 1.17 Cmtrsis as res itl.e .111.1 10, u Athotas hsrsars Tee rat tot.* *000.1 u.i* mate ear 100.000 am-yegt sisneareitae far aa ee tea situ iseuaa af tea am years ef all me taaastaa vanan ttaxes aa seam certificate laferaeciaai frw namana vt Ca. *4 047 Ragaidfag these detx the N10SH/ OSHA Asbestos Work Graap stated: adSthw. see weeid twpan death raws af wnham whs snaked This rats was danved bam the tern af the hushtsrass iUJ) ytos tbs axems ever rial haaaliaa due is sshaswi iMS-sUwerx) ptos the axcaw das w maldag |UU-tUwUtai Ths dsm sssm rate in asMafy s muMpUcalive awdri. II was shewn that smoking aioaa inenasad tht death mm sheet ll dews, and uhassaa slant tosraassd MI times. Ihsnfan. far a awSOpiteatrira medal dw wartsIIty rstw far tosea sxgstsd *e bath aabaataa tad awafaag weeid ha MIS news Ml emaa peeler Wan that* who wars nsavert neither to asbestos ear to weal tog The awrutBy raito far them xpomd to aabastea aad to ripwsitot waa acxally IUT (Ex a-m p, gyy Seiikoff Saidaax aad Hiounend euahmd the effects of dgaratta i^okifl| ixpQmn SKemneMe producrion workers. S67 of whom had smoking histories (Ex sa1SDI As in Hammond at si's study, comparison was made to tgt tad causespsdflc mortality ratea within each smokiog status eatsgory of ths American Cancer Society (ACS) cohort. Non smoking emoeite workers had s greater taaa S-iold tnnusss hi lung cancar risk compared to non-emokars in ths ACS cohort. wkiis smoking amosita workers had an slmnal S-foid iaersasa compared to their smoking ACS counterpart. Baaed on ths excess long cancer risk in non smohara. Seiikoff at aL stated that asbestos exposers alone produced an ingested risk of hmg cancer, although the inaeaee etnong non-emokara wag limited in tana* of total nomberi of sdd'tionsl dsathx For cigarette smoking asbestos workers. Seiikoff el tL described dm increered numbers if lung cancar deaths as "devastating ~ Seiikoff el al obeerred no increised risk of death from mssotheliomx ' ST 0 0 0 5 9 0 I * fcdcrel Enpixlur / Vail. 4fl. \,. 513 / Friday. Vuu,n:bt,r 4. 1MU / Ruli*s naJ RrquUiiunt 51109 -...;.(iimcnslinal uiKrr. and uxtaxlnsix ........is smoking amovili? workers to non-xmokiny .imosite .vurkers. ) /.tv;.' Dittos* end Chest X-ray i.cma/itiat. Ilemmond et aL reported rh.st asbestos!* workers who smoked in..- nr more pocks of cigarettes per dap c.id .in asbestos mortality rata 19 times higher than that of asbestos workers who Had never smoked regularly (Ex. 4-017). Hammond at ai. also reported that es-smokers who were asbestos workers had substantially lower death rates than asbestos workers who had not quit smoking. Weiss (Ex. H OPT) conducted a cheat X-ray and questionnaire survey of 100 asbestos teatile workers. Wetae reported that napkins workers had a 40% prevalences! pulmonary flbrosis and non-smoking workers had a 24% prevalence of pulmonary fibrosis. A gradient la risk of (throats was observed lor both inersaaiag ago end mersaaing duration of exposers. The ags distributions of the smokers and nonstokers were similar, as were the . median durations of exposure to atbestoa. Weim concluded that both asbestos exposure and dgarotte wnoking were associated with pulmonary fibrosis and that smoking sabsstos workers had a higher prevalence of Bbroota relative to non- Weiss dM not indicate whether the difference in palnuuiary tthroele prevalence bstwens smokera end noosankera was atetletictMy significant n8HA lwl4 the UpillMW. / tfcw difference ia prevaJenca of pulmonary (Ibrosia between naoksn sad nonimoksra using a chi-squared test of proportions end did not find a significant diffsranca (p gtsster than ai). la ion. Weiss. Levin, and Goodmss (Ex. 04-0W) rspested tbs results af a lurvey of 43 stsn agsd 40 er more wbo had worked 1 or autre years tat an asbestos Kcaufactariao plant The prevalence of plaurel plaques wee greater m cigarette smekene however, there was soma rnnfeendlng of this reiationship by rumulaWee sabsstos exposure, which also aoonwd m .oflusnes tha prevsiencs of ptaarsi plaques. Wriss at si itsted: "Condusions.aie restrsined tn rite al] numfat-t s( wwrkrts m this mvwnigatieu. A He tr-4.nl .inxwqr lu the qwstion ti lu wlH-ilwr the *surialuin beta ran pl-u--v xml .xhAiiiu tm ipunnai will rruuir* x much Ursw rrwwxlt rfforl. prrh-rahlv in cohort fiwit it sauna, p. em X-ray appearance uf pulmonary Mitosis nor rontnbolrd to fibrosis resulting from asbestos exposure. In summary, there is some rt idencr that smoking asbestos workers have a Prurie (Ex. 04-0791 survsysd 131 - higher nek of mortality from esbrstosit. asbestos-exposed shipyard workers to as well as a higher prevalence of dciermint the rebttlvs contributioo of crepitation, lung function decrements, sshestos exposurt and smoking to lung and small radiological opacities. This function deertmems snd chest X-ray almormalitiss. Pearls found thst both cigarette smoking snd ssbsstos exposure reduced FEVl (forced expiratory volume in 1 second) and FVC (forced vital capacity), with combined exposure having a "cumulative or possibly synergistic iffset" (Ex. 44-079. evidence is inconclusive. 4. Attrsbuting Prohab/e Cno/oyies r> iurny Concor Among intin niual Asbestos Workers Enteriine |Ex. *- 150) analysed the probability that any tingle ease of long cancer in a person with known exposure to asbestos could be attributed to the asbestos exposure p. 30). Pearls suo reported that both smoking tad asbestos sxposura His paper emphasised that it cannot be stated with certotnty that a lung cancer produced pleural snd interstitial bnorstnlitist and thst smoking ia aa individual worker wee due to asbestos exposure: rather, statements appeared to b the primary factor in airways obstruction and diffusion can only be made concerning prvbabtiiuas of cause snd effect. He impairment. Barry. Gilson. Holmes. Lewinsoka. and Roach (Ex. 04-020) studied 170 men convened observed relative risks into probebtliliee using the following formula: employed at an asbestos textile mill as of (una Mi 1000. Smoking histories ware available for 370 man. Man wars classified as havino never smoked, as ex-tmokera. or at currant smokers (tight, mediant er heavy cigarette consumption). The mean cumulative ItTS-fra il exposures (fibers/cubic centimeter, yean) were similar among the smoking statue groups, and age adjustments were made to account for the younger ages of nna aawhars. Significantly greater prevalences of crepitations and smelt radiological opedbet were observed ia heavy smokers and ex-smakars compared to non-smokers and light smokers. Per example. 10% of heavy smokers employed after 1990 had smell radiological opacities compared to tn of nevrr-emokers employed after 1950. KUburn (Ex. A4-237) has reviewed tha atudits of the relationship between cigarette smoking and X-ray avidanea of pulmonary fibrosis. KUburn critiaxed Using Selikoff at aL'a data on insulators, where e relative risk of about 4J we* observed for smoking asbestos workers and non-smoking asbestos workers alike. Enteriiae estimated a probability of 79% that lung cancers ware attributable to asbestos exposure for both smoking and non- smoking asbestos workers (33/4 100 is about 0l73|. Enteriine* paper is important in exploring the extent to which asbestos c-'' -H C2 t--i ,--. (_n 00 rvJ Waist's sat of a definition far can be considered tha etiologic agent for pulmonary fibrosis other then that of tha lung cancer in exposed workers. HO la his 1071 study, as wall aa the However, ia the cue of smoking small number of workers reported an in asbestos workers, dichotomising Writs's ion paper and hia other papara. causation as either due to smoking or A study by Saaet at aL which included due to asbestos dost not seem a r*Ulively large number of tcbfocte appropriate to OSHA. because of the and which did not find an effect of factor of synergism between cigarette operetta smoking on radiologic smoke and atbestoa. Using Selikoff tt abnormalities characteristic of L's data, probabilities of causation asbrstosia was cited. Kilburn concluded were estimated by OSHA for each that ogaratte smoking neither produced etiologic factor (See Tablu 9 and 7). 4 51110 Federal Reyietur / Vol. 48. No. 215 / Friday. November 4. 1983 / Ruler and Regulation! TaOlt 6 LIM CANCER MORTALITY IT SMOKING STATUS^ Lung Cancer Rett pgr 100.000 of Ter Smoking AtotSlot Insulators: 382.0 hon-Smk tng Attestor IntuUtort: 40.4 Seeking U.S. Malts: 74.4 hon-Smk Ing U.S. Mtltt 9.2 l/Proa Stllkoff tt *1.. (979 (Ex. 84490) TaOlt 7 PERCENT ATTRIBUTABLE RISK FROM ASBESTOS EXPOSURE ANO SMOKING Lung Ctnctr Rltk AttrtOutttlt To: Background. Atoestot along Smiting alone Inuraetlan of Seeking and Atoat tot Formula 9.2 1 AttrlOutaOlt RUN for Atouttot Workers: Stint Non-Seek Ing mm 2.SB 22.81 40.4 - 9.2- 31.2 8.6B 77.21 74.4 - 9.2- 8S.2 4 3G2 - 9.2 - - 31.2 - 88.2 258.4 18.OS 70.81 W75I TOGS Whtie OSHA'i calculation* d&ar From Enieriiner calculation! of ttr-buubie t by tndadlag lb* synergies factor, tha probability tatimatae dc not differ much. According tc OSHA'a calculatione. aabeatoa tiptwit contributor `a 7M4 and 772% of lung eanerr dratha among making arbrttar worker* and non-tanking aabeatoa worker* raapactlvaly. V Summary. OSHA conaidrra that aabeatoa expoaura by itaolf cun rauao tuny cancer, aabartoaia. moaothciionta. and ga*eointc*tifial malign*rtmr*. tbaraby prcaonting a ngnificant health rial to enpoaod workora and a pn danger under currant expoaura omuiitinea Cigaratta (making by Itaolf can cauao Hina (Haeaao and lung cancar. Ogaranc tmoea and aabeatoa expoaura appear to have a awlUpMeative mlatton*hip far ciuaatioa ef hang cancar. Mortality frea aabaatoaia baa boat reported to bo btaaaiad la dgaratta-amoking aabeatoa worfcara compared to oon^ooking aabeatoa workara. altboegb thia evidence la iaconcluMve. PLwal plague* and tba radiologic abnormalitioa cbaractenatic of pulmonary fibroma have aiao been reported to be more prevalent in cigaralte-ostoking aabeatoa workere (liia evidence ia alao inconduaive. Ex- aabeatoe workara bave been to beat decreeaed lung cancer rtak relative to amokiog aabeatoa workara. Than la no evidence for any ratadonabip between cigarette smoking and Induction of aieaotbellomaa and gaatrainteatinal malignandee. Rolath Caranoft/uaty and Toxicity ofDifforotu Fibort 1. Introduction. OSHA haa reviewed tba data concerning the relative carcinogenicity and toxicity of different aabeatoa fiber typer and haa decided not to make diatiactiona in thia emergency tamperary atandard by aabeatoa fiber type witb regard to regulatory proviaiona deetgned to protect workara from the harmful effecta of aabeatoa expoaura. Mainly, thia la becauaa lung cancar ia the loading cauaa of death aaaociaiad with aabeatoa expoaura and tbera do not appear tc be dtoenntiala in lung cancer rtak by fiber type. Some inveetigatora and rnmialtteea have niggeaied that different fiber typae of aabeatoa have difference! in their carcinogenic potency, including Enteriine and Handeraon (Ex. 44-122). McDonald and McDonald (Ex. 44-154). WeU at aL (Ex. 44-2D8). Acheron and Ceidnar Exa. 44-015 and 44-443). Muir (bb 14.110). and the Adviaory Committee on Aabeatoa (Ex. 44-2181. Thaea adentieta generally believe Jhaf croddoiite and amoaita are more carcinogenic than chryaotile and anthopbyilite. Baaed on there adentiata recommendation*. both the United Kingdom and the provinca of Ontario. Canada have promulgated the following atandarda tor aabeatoa: OX fibara par cubic eanttanatar (02 f/cc) (or croddoiite 05 tlbere par cubic centimeter (05 f/cc) far stoodt* 1 fiber par cubic centlmettr (1 f/oc) for chryaotile and all other forma of Recently, the United Kingdom haa announced raduedona ia the limita for chryaotile end amedteu It ia Important to note that the gueetfaa of diffaranuala la potency by fiber type primarily concema Induction af maaotbaUumna. not aabaatoaia and lung cancer. For maanthaile--. A charon and Cardaar in 18ft deaertbed "a powerful caae. * * that craddeiite bee been more dengeroue then chrysotilo end anthopbyllUa* (Ex. 54-214. p. ii). wharaaa they charactertxod evidence for : ST 0 0 0590 3 i Federal Register / Vol. 48 No. IU / Friday. November 4. 1983 / Rule* and Regulation! 51111 fiber typa differantiala kn risk from lung cantor add aibettosis at "inconclusive" nd "alight" respectively (Ex. 64-Jlt. a. in to IMS- Achaean and Cerdaer naiad: Pvntonasl mesothelioma hat aa atoxtai ovduaire relationship with exposure to tot amphibolae craddoliia and aaoatto" (Ex. 64-243. p. g) Coocamtog lung cancar. that aotad that although oat study (Waill at sL Ex. 64-206)hsd found a higher risk among workara axpoaad to crotidolita. no "elaar diatiactloa" of risk by libar typo could bo found whoa tho stop** of deae-response currea wore compared. Haooa. they concluded that availcbla evidence did not auppott tha aatumptioo that chryaotila wea a laaa potaat lung carcinogen (Ex. M-2U p. ) to IMS. tha Chronic Haixrd Advisory Panel on Aabaatoa (CHAP) coavanad by tha U.3. Conauaiar Product Safety Commtoatea alao reviewed tha ovtdaaca for fibar typo diffarentiala to' carunoganhr rtak (Ex. U HI). They coadudad that than wort incoaatataat and tocondusire flndtnga with tagaid to lung caacar diSaraatlala by fibar type. For parironaal maaothallmna. CHAP coadudad that apidawlologic atodiaa luggaatad that this diaaaaa waa taoat coouBoa to ameeito weaken. laaa common ta goddolite workers aad fan or aoo-axiataal to chryaotila workara. Evidaaca for a fibar typo dilTaraattol to pleural mesothelioma riak waa not conaidtfod by CHAP to bo aa itibataatld aa for peritoneal oMaotheiioma. Sotao health aaantiata who boitavo that tmdenca links atoddoiito exposure to a aubatanttal tocreaaa to mesothaitoaa nak have luggaatad laparata regulatory treaunaat far croadolite (Ex. 04-216). OSHA hoa baoa urged to canaidar requiring that wotkon txpoaad to croadolite or aabaatoa mixtures coaiauung croaddlta woar, appropriate reepinuru. irrespective of atrboRta concentreOoao of aabaatoa aad irretpacttoa of compliance with tho parnusaibia exposure Brett Furthermore. OSHA haa beta urged to coneidar requiring that aaipinyeoa axpoaad to croodulita bo informed af the potoatial greater rtaka ttaociatad wtth gaddoMto and the raaaooa tor requiring reopirutor uaaga whenever rrecldoilte axpoaaroa occur. OSHA torttoe comments oo thto nuggtatioa aad oa other alternative approachaa to aaparata regulatory traatmoai of craddoiito. Tbora are alao aaenttfle questions conewrung the tatotloiuhip batwaaa fiber dlwanalewi aad ability to caaaa diaaaaa. OSHA boliavaa that aabaatoa fibara longer than 6 micromem fgxm) cauae lung diaaaaa and cana-r. provided that 'ha ratio af libar length to fiber width ta 3:1 or greater. Evidence for riak within tha same industrial process. from fiber* leu than 3 im in length if Undoubtedly, this ta duo to tha scarcity inconclusive. of such occupational groups tinea moat A critical analytic of tho evidence occupational populations have bean concerning riak differentials by fibar exposed toj mixture of tong and abort type and war dimension follows. fibers. Therefore, moat of the data on 1 Epidomtotetk Goto--Introduction: differential risk bjr fibar size are from Commercial aabaatoa fiber typaa experimental atodiaa rather than including amositt. chryaotila. and rpidamtologic-stttdlas and-will be croadolite. have bean observed ta be discussed to taction (OKU Exponmontal aaodated with elevated risks af Data. . arbvstoeis. lung cancar. aad Evaluating tha relative carcinogenicity mesothelioma whether exposures occurred to a single fiber type or ta of the different aabaatoa fibar typaa involves eoaapartaoa of result* from various combtoattoos of fiber types (NIOSH/OSHA. IK Ex. 64-320). different epidemiologic studies. OSHA believde dial M is important to note the Excess hmg cancar risk and asbastosis potential difficulties of comparing have bean obaarvad to anthophyllita different occupational cobam. aabaatoa workara: however, no craaa of awaotiwltoow have bean reported among anthophyllita workara. For amodta. an aaaodattoo between axpoaurc and diaaaaa haa been obaarvad by tha following investigators: Setdman ot aL (Ex. H~OP% Anderson at aL (Ex. 64-OtF) and Murphy at ai. (Ex. 64-311) Per chryaotila. tha following tovaattgawta have obtained positive findings: McDonald at aL (Ex. 64-069). McDonald aad Fry (Ex 64-064) Liddell Standerdixad Mortality Itatioa (SMR's) are risk otauarea that are dapandant on tho ago dtoMhution (at well aa other factors) of tha particular ttudy population Ttdn la because tha values used for comparison, referred to aa the expected values, era derived from mortality rates specific for ago. rues, ease end calendar ported to tho comparison population Cancar riak rises with increasing age. so that as ot aL (Ex. 64-096). Nicholson at sL (Ex. 46-473) Xubtao at aL (Ex. 64-066) .older population would here highar expected vutuoa for cancar mortality. Oomaat ot aL (Ex. 64-037) and Achaaoa Misleading results may ba obtained and Gardner (Ex. 64-013) For whan comparing riak meamres for croddobto. positivv findings wan caacar among atitoy populations with abaarvad by tha following investigators: different underlying age distributions. (owes at aL (Ex. 84-136) Hobbs at aL An example of tho otialeadiag results (Ex. 64-131) aad McOoiuid aad torn may ba obtained to such aa McDonald (Ex. 6MM) Menrman at aL insuaea to given to Ex. 64-333. which (Ex. 6C-161) obaarvad aa axcaaa lot* ilhMtretts that SMR's of divers* study cancar riak among aethophyUita miaars populations may bo tha earns while tha to Finland, to addition, numerous actual axcaaa risk of mortality may vary studies have obaarvad aabaatoata. lung greatly because of differences to age caacar. and mesothelioma among distribution. Sox and calendar period of workara exposed la mixed fiber types observation alao effect expected values, (Hughes and WaiU Ex. 54-133: Waill at because woman hare lower mortality ai. Ex. 64-306: (onaa at ai. Ex. 64-Mk raise from hmg cancar and lung cancar any at aL Ex. 64-OBt Etotos and baa naan greatly tinea the 1940's length Simpson. Ex. 64-44X; Pita sit al. 64-OOc of follow-up it another pivotal variable lacquet al. Ex. 64-144: Seilkofl at aL. because of tha long latency panada Ex. II OK. Kobinaoo at aU Ex. 64-Ogfc ' nacaaaary tor development of lung aad Balaaiga Monte and Sayarre. Ex. 64- cancar and especially mtaothahoma. 016) Alia sevarel studies at talc minora EputeniokigicStudim of Lung aad miHers. whan tha tale conuiaad Concor. Maeothafioma ond Abiottotir tnmoUto aad antkophyUitt. have The following studtae examined lbs obaarvad axciaaaa of lung caacar aad question of differential long cancer nak lung disaast. aad reduction* ta by aabaatoa fibar typa by comparing tha pulmonary fanctson (Ktotofald at aL Ex. mortality axpariancaa of different 64-140.64-t4V Browu at al. Ex. 66-QSfc occupational cohorts: McDonald and Gamble ri ai- Ex. 64-161) la addition, McDonald (Ex. 64-134) Handsraoa and zeolite, sa asbestiform mtaanl found in Entoritoo ft*. 64-046) WaiU at aL (Ex. tho sod aad water ta two illiigaa to 64-606) McDonald aad Fry (Ex. 64-064) Turkey, may bo napoaaifato far thoaa aad Achaaoa ot al (lx. 64-013). Soma of viOogaa' Mgfe mortality rates from taosa ttudtos also addressed the ataaothaitoou (Artvtoll and Berta. Ex. question of differential mesothaUoma 44-016: Barit at aU Ex. 84-110) risk by fiber type. Soma additional OSHA is not aware of any studies of workers axpoaad to a single cpkl--riologi: shtdiet which sompara fiber typo are alao pertinent to wurkrrs axpwsad to different fibsi aiaaa evaluation of riak by fiber typa. CT 0 0 0 5 9 8 1 Sun federal Register / Vol. 48. No. ns / Friduy. November 4. 1M3 / Rules end Regulations including McDonald at eL (la. *4-005). Hobbs e< sL (la. H-1121 Weiss (la. *4- OMI. Deesent el sL (la. UR. and Berry and Newbouee (la. II OH). McDonald and McDonald (la. *4-154) tuuasttd that croddolite was more caittoogalc than chrysolite baaed an their comparison of the raortiHty of Canadian chtysotflo adaen and adOsn with that ofCanadian workers manufacturing croddoUta-coatainiag |ai masks, for gas mask worker*. 13% and 1M af dm observed deaths were respocdvoly. In contrast M and MW of the observed deaths among chrysolite miners and adIter* wore hem lung cancer and masothteteam respectively. One potential problem woe that dm personnel records of dm crocidoUta worker* war* tenompteta. which could roouit in biases towaid observing pastor or leaser risk in dds cohort An unpublished report by Or. Han K. Kang (Ex. *4-110) commented as fellows on this comparison: (1) Two em)or potential confounding factor*, fiber visa distribution and Hber concentration, were not analyued by dm authors. If dm gas smak plants had highar flbar eoneantradona and/or a * higher pmporttan of long thin Bban than the wtnso. a higher runner risk would be (SMTa| and Ptoporttenato Mortality Redo* (FMX*s) might not bo appropriate batwaan the turn ooeapottenal eeharm because of potential dUhranoea in aga distribution and length of fallow^ Handarson and Eotarilaa (Ex. S4-04S) compand mortality of retired worker* exposed to different aabaetoa flbar types. After adjusting far dlifaranrea in cmnuiative dust aepeauraa. Handanon and Eatarlina reported tha faOowtng rasperstor? system cancar flkdRTs ter woriuns bi an aabastns feclary and wotfcaw maimfactwtng aabaaiaa earnest MFl chrysolite i only, and an farworksra rue crotedoUtx Aabaatbe camant pipo worker* had a vary Ugh log cancar 3MK of 322. Handanon and Enter!iao stated: "Men whe worked ic tbs production af nsbaataa cement pipe aahlbttnd a hlghw risk of respiratory cancar. as Adman with soma theaa two groups overlap, wa esuid sot be certain that crocidoUta asbestos was responsible far tha tacraaaed risk" (Ex. ao-ans). Concerning Handanon and Enlarilna't ooo or omro years of employment and at findings. OSHA notes that tha asbestos Wait u years ef foflow-sp had a lung ceamnt pipe exposmos may bars bean cancar AIR that was approximately dueliar than earlier estimates indicated twice as Ugh as that af Quebec aunars and that soma of tha workers thought to with one or mors yaara of amploymant hove boon exposed only to chrysolite and at least a yean of fellow ap. moy hove had Indirect exposure to Comparison of those two graupo of ctotedoflte. Also, workers in fte tsbtstos cement pipe operation potaatlol dUbraneoo in ago distribution, probably won exposed omody to chrysolite (Kang. Ex. *4-119). Another flbar concentrations, aadWngth of employment (Kang. Ex. *4-UR. potential confounding factor was that exposure levels wars uncertain lor each group of workers. Woifl. Hughes, and Waggenapnck (Ex. H4N| ttrdn dm mortality of asbestos Achaean. Gardner. PippardL. and Crinm (Ex *4-011) studied amrtaUty of famate workers manufacturing mostly rltgrinllls rnnialalnggai erailia In mu plant (Plant t) daring 1M and famate the Brat plant workers ware exposed m both cratedotlte (3A of product) and chrysolite. In tha second plant, workers won exposed to chiyoodle. oowsito (IS of product), end croddolite (iouvnt&lMi Wul et si rpo.!a respiratory system cancer SMR's os fellows for workers ncohring coamtettvo tsbastes oopoourao poster than 200 million portteteo par cubic footmontha (mpef- OMatha) daring tha lint go yuan of and i masks in a aecood plant in m (Flint Z). Plant 2 hadalargmaxcnaaof mortality than Plant t. Agee at initial omploymsnt warm vary similar at dm X plants. At Flam 17 varans 4J expected (SMKw Ml. statistically nan-significant}. Ona death from plaarml i (SMRwgo. p tern an). MssothsMnms JMt>w Q3KA notes that the apparent typo observed by Wofll at aL on baaod on ralabvoly anil niirabsra ef dastha Hence, rtatterical variatton may be consMant^t possible axpianatlon far if tha 73% failow-up rate may have contributed to thssa apparent WoOI. ZteUad. Waggmmpack. md Fnaeitm (Ex eo-gOT) ntggnte i that moddahte mmoaod workara hnd pooraa pnlmanmy famtetan than wastes txposod to othar farms of asbestos. TVey npotted that ooddattte woiktn had matter teng vnhamax s highar pravolmma af X-ray changes-lower FEW*. and ndeead dlfhmtag capacity. Mate PIKlrafaraw teavatemaafter *---~r--"--------------- - edasjtemmaiy mnVtaad wviaflia Waste t*erii*d carttficatea, g of which eodad masothaltema as thn imdmlplng causa of death. A statistically teprilteam taaoam in ovarian ennoar mortality was also observed at Rant I fU deaths SMRwgyg, p teas than 001). feasibly, tha daathn oortlflnd an due to ovarian cancar may have actually boon mtaclaatiliad paritanaal maaotballomax Acbaann at aL condoded that "the patten of mortality la conatetant with tha view that maaothabnom (and possibly evorian canear) b particularly anodeted with ogoont to crotedcUte* (ExM-OU.p.MTE Acboton at aL'o study ban t adwntigm raiattvu to othar stadia* of idiflaraat : both tha age i af fallow op warn temflar far Flam land Flam A Ntethar ter oanemmttaas nor durations of ernpleyrnam worn tepertad far tha S plantx however, loosum Flam S had bean oparaltag longer than Flam LFUm Xwockms may have bad a gratae A campariaan batwaan Canadian chrysolite minan studted by McDonald at uL (Ex It OOTj and Australian croddoUte miners stadted by Hobba at tlffxM US) hue bean made by Kang (*x M-lMl Tbs Australian Bursts with at Flam t white mirkialral pracocam wma employed at Ram A Perhaps tha manual ptacate led to Ughar date oaonifM faf Ai iiMthnniil wofktfi it Flam L Yat It la also possible that tha mechanical ptoecu at Flam t reduced ST0005985 federal Rcgislor / Vol. * No. 215 / Friday. November 4. 1983 / Rules ir.d Rr^ilatiofu 51113 ih* dismetera of (ha fiber*, rendering them more hatardaa*. OSHA considers that thi* (tody provides auggoativ* evidanea for a liber type differential ia mesothelioma risk howevar. this evidence ia not conclusive bacauaa of the lack of information on the air concentration* and darndona of IMlOyiMSL Both planta had aaeariee of lung cancer mortality, although only the Riant 2 axeaaa waa atatlatically significant OSHA calculated that the statistical power to detect a SOX Increaaa la lung cancer risk was only III at Plant L Civet! the low power to detect Increased halt at Plant 1. OSHA boMovea the statistically nao-tffniflcaat excess of luag cancer at Plant t should not be diareaarded. Alea Achseon et el calculated BM confidence intervals far lung cancer, mortality as 135-38? far Plant 2 and H at far Plant 1. In OSHA's vtnw. theaa overlapping confidence intarvala far the 1 plants radical* that tha abaarvad differences ia lung cancer mortality cannot bo considered statistically different. Hence. OSHA concludes thet Acheson et si's study doea not sstebiiah the existence of a diflarantial in lung canear riak by fiber type in theaa 2 occepatlonal cohorts. Weiss (Ex. aa-tMl studied a cohort of 284 production workere In a paper and millboard factory. This factory had used only chryaotilo sibestoe No ineroasod mortality Beni hag eanoar waa obeatvad among thee* workers (4 lung cancer deaths abaarvad vereua AJ2 expected). Two amn died of ebestoeie OSHA noted Uadtattona of Wdas'a study that tacduds lack of asbeetao expoeure d-ta and vary low statistical power. OSHA calculated that this study had only 20uM power a detect a 901 increase in lung cancer risk. Hence. OSHA doa* not consider Weiee's study ts rsliable evidence allow renew hak among chrysettle worker*. Dement et al. (Ex. It 087) obaarvad a high lung cancer riak among ckryaotilo textile workare (St doalha sbitwri venue 11.10 svpscfA 8MB will). A high risk of mortality hem non* malignant respiratory dfaoasaa. including aiheatiwfa. wee afao observed in thiscohort (21 deethe obeerved versus U3 expected. SMBa2M). One peritoneal mssntheBome wea confirmed by autopsy. Several other death certificate* listed "canear of :ha abdomen." bet tha aathon were anabla to obtain additional data to datarmlna whether theaa perticuter cancers vrera actually meeothettomas. Expected vsiuea for mortality were derived from UX mcrtelity rates. Dement et aL auggeated that tha higier.risk of respiratory canctr mortslity in their chryaotiie exposed cohort compared to cohorta of chrysotila miners end millers may have bean due to different fiber sixe distributions. Using sxpeewd values of lung cancer mortality derived from the South Carolina county in which tha chryeodlo textile plant was faceted, instead of UX mortality rates, would hove reduced the lung cancer SMB's far the cohort because lung eanoar mortality rotas rare TS% higher in the county than in the United States aa a whole. Dement at L considered use of the county rates to be inappropriate because of the ' probable contribution of a nearby shipyard aa wall aa tha study plant to tha elevated long cancer rates in tha county. Stale (South Carolina) atortaiity rates bom lung cancer wet* similar to those of tbo United States. Dement at aL also addressed the poeaibility of confounding effects from smoking. Queshonnalraa administered ia 1984 and 1921 to workers employed at tha pleat did not indicate that tha study cohort had a higher prevalence of smnltlng compared to the UX popoJAtMML OSHA regards Dement et aL's study aa taong evidence of the potential far high tang cancer hak from axpoanra la ehrytotiia. McDonald and Pry.fEx. 54-004) published i preliminary report on their study of 2 asbestos factories (Plants A and B) when chrytotlfa waa used xcfaahmiy and 1 factory (Heat C) where chryaotilo. smosits. and crochfalitt were used. Plant A was tha ttedy plant reported on by Dement and ccHeayam. Plant C had provtooaly been studied by Unfititson and colleagues. Respiratory system cancer mortality waa in excaaa at all 3 pleats. Expectad values for each plant were dertirad from the age. sex. tad eause-epedfle mortality rates of the states in which the plants wan located. SMB's won calculated begiaaiag 20 yean after initial employment at tha planta. Air ooncenBaitoaa wan highest in Plant C. next to highset In Bant A. and lowest ia Bant I. Criteria far Inclusion in tha study cohorts won: (1) One omth ar mors of smpioymant by fanuary 1.1988. and (2) having any Sodal Security Administration files. Vital status was daiaraifrssd as of December 31.1927. The overall respiratory system eanoar SMB vu 288 al Plant A. cor.firming tbo high hat| cancer hak obaarvad at tha same plant by Deeiaot and colleagues. Hetharoara. McDonald and Fry noted that (hair iaduaion of clerical workara and wotksra with 1-8 months of sxpomtra ia tha cohort, unlike Dement et sU probably reduced observed respiratory cancer risk. Among mala workers employed 1-1 yeers al Plants A. B. and C respiratory system cancer SMR't ware 2S. 148. and 41 respect!veiy. Among male workers employed 20 or nan yean at Plante A. 8. and C. respiratory lyatam cancer SMR's worn 31*. 188. and 140 respectively. Tbo lower respiratory cancer itskia men in Plant Cures unexpected. given tha higher air concentrebona in Plant C A diffaraftt pattara of respiratory eystom cartcw risk was apparent for female workers compared to stale workare however, the female mortality rates were not stable because of the . small Dumber of deethe. Female workers ia Pleats A. & and C had respiratory system canear SMB'* of 234. 34* and 32 respectively. McDonald and Fry charactarixad the differences ia the distribution of mesothelioma deaths among tha 3 plants as "striking.'* Plant A had 1 death from mesothelioma (-am of aU deaths) and Plant B had an death* from meaothelioma. Plant C had 18 deaths from maanthalinma (UM of all deaths). Possibly, aa even greeter number of deaths bom mesothelioma oeeanrad at Plant C. da* to anracognlaad cases bafag coded aa abdominal cancan or other/ unspecified cancer*. Robin*oo rt *L (Ex. *4-0*2) had also obaarvad a high mesothelioma risk among workers at Plant C McDonald and Pry oanaldarad tha probability of --i--truo case* of meeotheikxna at Plena A and B to be low becauee of good cancer ceee ascertainment in the trees where these planta were located. McDonald and Ply stated that axpoeure- respaoaa relationships at tha 3 plants might be denBad after the individual subiects were classified by exposure levels. OSHA conaidar* the following poults important far interpreting tha findings of McDonald and Fly. Although McDonald and Fry stratified by duraban of c/"> txpeeura far their inter-plant __ | comparison of lung cancer mortality. t( other portant variables ware not controlled far. Including age at initial a employment. fiber concentration, tod 0 length of follow-up. PlantC. which had <-n the peatest number of deaths from to awsathsllnres also had tha highest ,--. txpoaura level*. Hence. OSHA qj considers that the diSarantials ia mesothelioma risk among tha 3 plants an auggaetiva. but do sot conclusively demonstrate increased mesothelioma risk from crocdoiits relative to other ubettoe fiber types. Of interest la tha finding of higher lung rancor risks si the ckrytotile plants (A and B) relative to plant C Again, tha variable* of fiber ( ti t T rm T m T V 31114 federal Register / Vol 48. No. 213 / Friday. November 4. 1963 / Rtilaa and Restitutions copcvniratkm. sge distribution. and length of follow-up dead to be controlled for when comparing long cancer risk at dilfmat cohorts. Barry and Newhouss (Ea. and Nowhoua*. Barry, and Sktdnwn (Ea. 44- IS) itudie* the omrtailty at a cohort of worfcan awaufectartng frictiaa material*. tapoaan woe lo chrytotfle xdusiveiy. azeapr daring 1P2P-1H3 and IM-N44 whan a null percentage of (ha workfare* waa exposed la eroddolite. Aabaataa oapoaaraa were law in Iha plant; only t% at the otofa orh*n arcumalatad aa much aa 100 f/ cc-yesra. The only caaaa of death far atloloprc Cactoro far mosotkollawa. a matched earn contra!^study waa For each caaa. 4 contmfa warn aafadad from the plant Coomb wara matched on yoor of hfe* at the factory, aox. ago. and duntfaa at amployaiant. Definite anadolila capoeira waa dlacorated ia the occupational hlatwrtaa far af the to meanthalinma caaaa aad far a af the 40 control*. Abeal IM af the i 2W of the coomb kad laeaia of chryaadlo awooodlng t/cfc When Berry aad Newhoaao Uarited thair eampariaos to thoaa caaaa aad owtdwd coatrala who had been aapoaad la aver St/ee of chryootil*. a atatiattcaJly significant greater number at < an aocapatMoal binary of t aaddalita aa watt. Matching the oantrala far the mesothelioma caaaa aa year of hfee ooomifad (or the important factor of length of tollowap. OSHA aaaddma that both croodoliaa and dtryaotflo are implicated in the raneartoo of .-nceaihetioma by thia study? chryaatlla because aott of the caaaa facateed high chryaoiila axpoamei compand to at af the tottroll, aad crocidolit# bocaaaa aw ef the caaaa ewapatad to tJ% at the control* had bm aaddalita. The Chronic Hetard Advisory Nad oa Arbettor ICHAP) coaapusud laag cancer risk par wit at caaaaladao espoaun (alao kaawo aa dm laag cancar petaacy factor) among *n soliera aapoaad to dlfhmn fiber types. CHAP reported that studfaa af chryaatlla myfakhd bath low and Mob values of Kt, aa wall aa atudbs at crocidolite werkan aad ameaite workeri. Nrttct. CHAP considered that evidence for e diffarkntial in lung cancer . nek wae mined end inconclusive (Ea. 4-2ML Pathology Studiat: Wagner. Barry, and Poolry (Ex. gt-KB) axaminad the aebcetaa contanta of tissue camplaa at lung* of aebtetec textile worker* who died (ram meaothelioaia and other causa*. Wagner at aL did not find either hlghar chrysotifa or higher aochialil* contanta ia th* lung* of the mesolhdioata caaaa oompered to th* lung* of eebaeta* workers who diad from othar causes. McOanald. McDonald, and Poofay (Ex. P4-1TS) conducted a etudy of ilia mineral fiber contanta of lung ttaeoaa for N autopeiad mesothelioma case* and M anlepafad coatrala. Caatrab matched (or tax aad age wan talactad for each mesothaUoma caaa. All controls had bean dlagneaed aa having pobaonary motaaiaaoa from a primary cancar otbsr than lung caacar. Lung tiaaua specimens wan examined far mineral fiber content using aa electron miacroaeopc and X-ny energy-dispersive analyter. Chrysolite. amoalta. aoadoitta. aathophydita. aad tnmolita wen datactad b th* hing epedmana af the cases and controls. For amoalta aad cromdoHi*. about S timaa aa many mesothelioma case* as controls had own than I miUloo fibers par gram of dried lung ttssue. Far anthopayilit*. twice aa many caaaa aa caatrab had awn lima 1 million f/graab Far chryaatib aad tnmalib. little dilTanoca b fiber caataat* waa eimanad between McDonald. McDonald, and Poaiay stated: "Th* aqua! quaMitt** at chryaatib fiban found in lung tissue front caaa* aad control* fail to aupport any aaaooatloa between thla miaaral type of ssbaatoa and maaotbaiial tumor*. Howavw. thelung cbrysotil* fibn eontaai at daath awat be istarpnwd caotteealy. aa thaae fibre* probably dbappaar te th# count of lima* (Ex. *- imp. sdl Than an aowml poiata W consider cewcamiag McDonald at aL'a study. FtaL If tha (ban napcaaibb (or raspoasibb far caacar* at titaa otbor than tb* lung ana maaothaiium. than a true effect of a fiber oa masothoboma ganasb could fail to ba detected because ef the stipulation that all controls had to have pulmonary owisatasa*. Casinintostiaal cancan sometimes matastaaoa to tha lung.. . some atadiaa have observed aaccassa of gaatntaiMUnal cancar among aabaataa workara. Second, alnca chryaatib conatitutaa up to flW af caowwrdally uaod aabaataa and tine* aabaataa oxpoaun if ubiquitous. ana would axpact caatrab te have chryaoiila fibora ia their lung*. Th* widespread axpoaun to chrysolite could obtain a tnm rafatibnahlp batwtsa ebryaotib aad McOanald at aL auggastad that chryaatib stay bo eband faster from the laag* than othar aabaataa fiban. to that chryaatib mtaatfan in tha lungs euy not ba th* beat way to estimate dnyaettb axpoaun. Rowlands. Cibba. and McDonald (Ea. I4-I7t| auggastad a tand*ncy for chryaatib to ba removed from the lungs because of their obaarvstion that the quantity of tramoiit* fa tha longs of Quebec abasia and oufiars wat similar to that at chryaatib. daapita th* miaom* much pastor axpoaun to chryaatib. la gaaanL OSHAbaifava* that tha nsulu of autopsy studies ef fiber content at lungs cannot serve os diract massuns of risk diffenadals by fibqr typo. Maaothaiioma Finding*: As mentionad ia Ika introduction to thb section. the prinury boob far tha hypothesis diet crecidolllo b men oardnoatnlc then other farms of aabotwa b the obaatvod varbdaa in moaotholiomo mortality among cohort* expoand te difierent fiber typo*. A summary of the pareantago of deaths from masathtiioma among oohorta exposed to difftnnt fiber typos follows. Meatman at aL (Ex. Sd-atL who obaarvad excaaa lung cancer mortality among antbapbyQlta miners, did no: find any daatba from maaothalinma in thair cohort, la Saidaua at *L'i cohort at amosila inaulaboa predoedoo workara. a total at 14 mesothaLomsa wan tofaatiflad by death certificate at poihologtcal reports (Ex. 44-0S7L Those 14 deaths from maaothaUoaw consbtutod JJ% of total deaths in this ~ oO __ ; ,__ , _ oi co cs Cohorts of chrysodb workers had relatively low porconiagoo of deaths from mesothelioma: federal RcgiMer / VoL & No. 213 / Friday. November 4. IBM / Ruin and Regulations S1115 Tania HtSOTHCLlOW DEATHS AMONG C0HC8TS OF OdTSOTOf wOAtfftS Study t of oaatns froa aasotnolioNa MeOonald et a). (Ex. 84-0dS) - aliwrs Ntcholton et al. (Cz. 04-072) - Ninon . Oaamnt at al. ita. 84-037) tozttla uorkan 0-1 - o.s o.s Huh(no at al. iCa. 84-088) - Ninon 0 mesothelioma risk. pariiculeriy peritoneal atesotheiioraa. by fiber type ia more consistent Umn for lung cancer. Xonctheiesa. tkw evidence appears not lo be condemn becaeae at failure by moat investigators to control lor important variables when comparing difbMt ooo^ctiiBcl oohofti* Meeotbellome ridi la effected by the aeorn vartabfa* diet determine (be degree of lung cancer risk. Furthermore, mesothelioma bee a longer latency period dun aebettoannoticed lung cancer and rieee exponentially with increasing due tiaca initial exposure, anch thatlength af obeamHon ie a variable that meat be controlled Tor in 00GSG001S i Hammond at aL however, obeerved a higher percentage at dontha from mesothelioma (Ex. 84-047). Hammond at aL atudied inaulatioa worker* axpoeed predominantly to chrynotilo and to eomo amoatta. bet none croddollto. Fiom death cart!fleatea and other dhdcnl material. ITS deathe (T^X) ware attributad to maaothelioma out ofa total of 2271 deaths. Patt (Ex. 88-188) etudUd a factory wtuth need moetty chryeotflo and aoma aeddoilto. and (bund a' high maaothalioma rink. Robinson at aL (Ex. M-oaz) obaarred IS of doaihn from maaothalioma in cohort whare dm factory naod the following porroniopm of aabaatoa liber types iliiiautlla 881 amoaata--O0% and croddoUte--4OT. Among aoddoUlo worfcam. McDonald and McDonald (Ex. H4M| observed its of deaths bom maaothalioma. |ooaa et aL abeam ad US of daatha from moeotbeUaan (Ex. 88138). McDonald aad Fry (Ex. M-OM) obaarred IASS of deethe from meedtheiiooM. and Hobbe at aL (Ex. 84132) observed 9% at deaths bom mesothelioma. The Chronic Hazard Advisory Final or. Aabaatoa (CHAP) stated that pantonaai maaothallnom 'appear* to bo moat common in wuefcme expcaad to amoatta. lata often to eroddoiit*. end rarely or never to diryaoeUa" (Ex. H> 298. p. 127). However. CHAF acted the Urge Venetian in parltonanl mesothelioma mortality among crecidolitf worker*. tha lack at rich daw axprmaad in tarau of unit exposure. aad iha fraojsfll misdiagnosis of peritonaal maaothelioma. Cotuan irmly. Cl LAP tuggeaied that factor* trihrr than fiber typo, such as fiber diewottoo. may be important for Hiducnon of peritoneal meeotheltoma. For piaurjl morothelionu. the jiffmiim is mortality among cohort* were iuit at merited as for peritoneal mesothelioma, according to CHAP (Etc M 238. p. 128). Summary af Fftidttniolagte Data: In eammnry. there in evidence that all commercial asbestos fiber types, except for anthopbyUita. cause aebeetoaU. mesothelioma. aad hma cancer in humane AalhophyUHahas bean shown to causa Iunf GIBCV Slid bttt no meootheiioinai have been reported among worker* axpoeed in anthopbyUita. For long cancer. OSHA vtewe the evidence for differentiate is risk by fiber type ae inconclusive and iacotuistesL Soma studies have found that chryeotila mother* have roughly tha tamo or higher risk of luag cancer compared te worker* exposed to amphlbdto fibers while other etndfoe have found that chryaotik workan had somewhat lower relative risks of lung cancer. A* disc*seed by CHAP with ragard to thoir comperiaon of hmg - cancer risk par unit of cumulative exposure, conaieteni panama of higher lucg cancer risk among workan ixpoaed to croadohto end emosite did not emerge. With some exceptions comparisons of lung cancer risk among wriin^nHfui cohorti txpuMd lo diiTerent fibers generally have failed to control far tho following variables: Fiber concentration*. ago distribution, and length of obaarvatian. Tbaaa variablaa an aufllciaatly important daiarminanta of ooboatoo induced Ung cancer riak such that OSHA beilevea tbaaa perilcufaf crnae*cobort comperieone provided Inronciuoieo evidence concerning difTanncas la carcinogenic potency at tho various fiber*. Other important vansbias that may confound croaa>cahari comparionns era flbar tUa distributions. hygienic awasun* instituted by tho companies, and respirator aae. Tha evidence lor a differential in Cbryeottle Is long caidnogen for humans. Even If chiyaotile could bn definitively shown to induce fewer maaothalioma* than the other form* of asbestos. OSHA btlievn* that epidemiologic studio* indicate that chrynottfo post* a tipuficut haalth riak to hnmaan by iadodng long cancar aad asbaatosie. OSHA ha* conchtdad that fiber type ia not on important datanninaat of lung cancar mortality arising from asbestos exposure. Bacausa luag eaaoar is tha maior cans# of axcase mortality among aabaatoa workers. OSHA does not d**m it appropriate to permit higher lavait of axposura to chrysodl* than to othor asboatoo fibar typos oo tho basis of tho poaaftilUty that caryaodis aiy indues fowar meaotheUaaiaa than tha itaphlhilaa (amoatta, ctoddoUieL X SrparltHaatatData. OSHA baiiavaa that niimmoim atadlaa af laboratory aalatah evpneod ta aabaatoa haaa foand that the rlimwisinns if ffiren rathsr than typos of fibers are major dataroiinaau of riak for hang disease and cancer (Hariagtoo. Ex. 64-121; Pod. Ex. 88-17X Stanton. Ex, 88-81 84-188: Wagnar at aL Ex. 84-108: Writht aad Kuachner. Ex. 84-210). Aspect raBoa (la. length to width redos) of fibers have also bean iiiggaitad u fanors Influannng carcinepaaldty (Barinad aad Pazaret. Ex. 88-1141. Bacaaaa fibar sms diatribudon appear* to affect disaaaa catalog potency, tha toarce af tha asbestos aaad for laboratory axporimonu aad the methoda uaad to predoov dM ubvioi "ckodi" ^ conaldorad whoa tntarpretlnj tha results of laboratory axpunmanta Chrysolite. amoatta. and craddoiita hove oil inducad cancer (a aniawla upon administration by inhalation. injaettoo sad impfoatatkm (NJOSH. Ex. 14 lilt MOSH/OSHA. Ex. 84-320: Wagnar at aL Ex. B> TfH: Davis et si. Ex. Davis ai aL found that UICC chrytatila i, fr 31116 Fodoral Rdgiator / Vwl 4S. No. 119 / FriJay. November 4. inM^^ulc^ind_RcguU|K)ni^ produced oral* fibrosis tn rat* via mhalaiKMi than did U1GC amoeit* Factory sample* of dwyMib. however, produced a similar degree of flbroai* via inhalation eomporad to factory aaaiplaa of amoaita. Wagnaret al conducted khalattea studies of U10C aabaatoa naiplaa |1 diryaotil* 1 amphibote) in C/D Wlatar rata, and found similar dagrau of pulmonary flbroaia and long honor incidence* liar all aapoaad groapo (la. M 04a).IJha Union Internationale Contra Caacar (UICC) waa tba aouroa fof thtllblllM AbVMMpllMIltfil tho study.) Animate aapoaad to tho 1 ehryaotila tampioa retained amch Waa dual in thair fan* at tha and of tha axpoaoro parted* than tho 3 othar aapoaad poop* Coacarning tbia study, tha NIOSH/OSHA Aabaatoa Work Croup cammentat "In tanna of dagraa of toaponaa raialod to tha quantity of duat dapoaitod and ratainad in the luap of rata, ckiyaotik apponra to ba modi man fibwguir and catdnoganic than tho anpWboiaa'* (Ex. >4-110. p. IS). Of intaroat war* tha mesotheliomas occumnf altar only ono day of axpoaoro to aoMaiia and moradolit* Intraplaorol administration of various forma of aabaatoa ptodocod tha Mowing incidence of masotheiiomaa: crocidolito--am. amooite--JM. anthophyllllo IW. Canadian ehryaotila--JO*, and Rhodaaiaa chryaottia--M (Wapar at aL Ex. MItrj. In contraoL Stanton and Wranch (Ex. at-HO) did not obaarra diffaranoaa In mesothelioma incidence by fiber typo wtth intrapleural Implantation. Chryaodlo may act aa a in addittoo to adltq aa a primary carcinogen. Kcng-Vouma* and V'lnkmaan (Ex. 44-143) abeanred a atrottg mtaroctian bonoeon chryaotile cunmistered Intratrachaally and N> nitroaodiethyiaaina adminiilarad orally with repaid to prodoetton of hug tamora in bamatata. N dtroaodiathylamina baa boon daoMoaMtad to ba carcinogenic to many different aparioa by different router of adadatoui In 1477. StxaiaaL LnyardL T Miller. May. and Kant pobBahod tho roaultr of taeta of 17 fibrous glaraaa of varying typoa and itimanaiima (Ex. 44003). Tbaaa fibrosa glareaa ware ' impiantad la tha pteurno of female Qeborne Mendel rota, and surviving aniirala wore sacrificed altar 2 year* Statistical analyaae indteatad teat tha Short laaa than or equal to U mitfjmotan (paal In diamaiar and longer than pm produced the Mphoot incidence of piraral sarcoma* Fiber* laaa than |tm :n length appeared to ba inactivated by phcgocytoaia. (ftixgocytoaie ia the engulfing of foreign particle* by phagocyte* which art celia that usually digeat thaaa particle* in order lo protect tho body from them.| Sumo- * aL stated; "Since neoplastic response te a variety of type* of durable fiber*, particularly aabaatoa fiber*, waa elmitor. oar axpaiiraants reinforce tha idea that the earctnogenidty of fiber* depend* on dlmanaleo aad durability rather duo phyairnchemical propaniaa and amphaalta that all raapirabia flbara should ba viewed with camion" (Ex. 44on. p.SV% OSHA behave* that SUnton at aL`a study baa important hnplkatiana for the question of fiber type dUTarantiaia ia risk. Tha study suggests that any obaarvod diffarancaa in risk by fiber typo may ba doe to diffarancaa ia tba fiber ateo dtetrtbutten within the worfcpiacoe being ampand rather than inherent chemical praportteo of the particular fiber*. Stanton at aL`a study euggeeta that fibrose matertala besides aabaatoa can produce a carctnoganic raaponaa In both tba pleura and peritoneum, provided that tbaaa materials pessaaa carcinogenic dimension*. Among tba flbrooa materiel* demonstrated by Suntoo at al to produce malignant tutnora fallowing implantation are: All forma of aabaatoa. including amoait* antbopbyUlt* ehryaotila. cnddollta. and trumoiitK boctMiUcatc cIim; ijticiii Twoofc aluminum oxide * vtfftooft cubits tcarbonalm woHaatoolla: and atupulgita. It ahould bn notad that Stanton at oL's atudy did not role out rnirliwganldty of flbora oatnldo of tho tHmonaione ahown to bo Suntoo at oL (19*1) continued thair implaaUMan oxporimont* graady expanding tha number of durable attainlo uidadirtg aabaatoa. tasted via Implantation into tba plauraa of fomalo Oiboma Mendel nu (Ex. 44-1481 Stanton ot aL nbaarvad that the moat cardnoganic fiber* wan tho*# 033 pm or loos tn dlamour and grsatar than 4 pm in kagtte however, high conalatioaa with rarrinoganir|ty wan also observed for fiber* 14 pm or Was in diamatar aad longer than 4 pm. Wright and Kaachnar (Ex. 44-2101 studied tha production of fibres!* by ictratncboal intention of uboatoo fibon in guinea pip. They obaorvad fibrada only from aabaatoa fibors longor that 10 poa. Cibb* and Hwang (Ex. 44-UOI PMBnl OV (Ml nCMMlwl pfMNHI aaiitg aabaatoa omy raduce tho parcantapof abettor Hbara in tho air. NIMH (Fletak. doth. FlaaaU. StalL and Utah) conducted o study of ho chronic afTtctt of inhalation of short ahtstao fiber* with abort fibors defined a* those less than 9 micrometers (pmf in length (Ex. 44-2301 Both rats and munkryi wort axpooad to a ehryaotila aaiieatoa aerosol for 14 month* Tho surviving rat* won obaorvad for 4 months Mowing tho caseation of expooura. Neither pulmonary flbroaia oor tamora wore Increased In tho ixpossd rata compand to tho control rat* Mookoya ait being matouioad for aa indoflnlto parted foliowing oxpoaun u detonate# tho chronic affect* of txpoaura. Tb* NIOSH invastigator* encountered eoowdifflculttea te trying to generate short fibar* Tba ball milling method waa used te ganarata fiber* resulting in aabaatoa bolla that could not mam the daairad 3:1 aspect ratio. Some problems also occurred with regard to tho method* of counting uboatoo fibors and determining aerodynamic diameters (Ex. 44-230). Consequently. OSHA conaider* that Plataket tl*a study providu laggesttvs but not conciualv* avidanca that short osbuteo fibon do not Induct pulmonary fibroeia or tumors. Somo chomteta bov* poaiud that aabaatoa fibors bava biochemically active situ on thair tuffoets that can be aradUled so u teradueo tha hazardous pottntUl of aabaatoa fibers (Ex. 84-3331 lha alactrteal dorp of chemical group an the surface of oaboateo Abort hu boon hypothoaiiod to lafiuanca toxicity of fibon* For axampla ooo chatmcai procau ramovu tha magnoaium bydroxido group on tho surface of chryaodlo and rapleu* thorn with ettenol psug* producing . form of. ubostu known u aitenixod aibetto* In vitro taott (taata conducted on cell* in teat-tuba stmuleboos of living systems) hove won conductad for normal asbestos fibon end chemicaUy-trvatad asbaotot fibon. Doaaoaad toxicity in chaotically treated ubutos fibon eomporad to normal asbaeto* fibers baa bean raportad (E* 44-333). OSHA canaMon that tha hypo(hasta that biochemically aettva situ on tha turiaca of oaboatw fibors determine tha degrae afcarcioapnirlty of tha fibon ia not urefi aappartod at this dm* This ia bacoou many in vivo studio* eapooally thou ooaducted by Stanton ot oi. have found that fibar dimanatena rathar than chamlcal popart!** apuaarad to ba the primary datorminoet of fibar carcmopnlclty. Stanton at el found that a satiety of nan aabaatoa fibar* could induct concur, if they ware milled to igaciflc dlmaiuten* Tha in vitro atudiu of chamicaily traatad aabaatu an not u datarminauva of hulth risk u tho tn vivo studies of Cbm dimer.sion and hanca do not refute tha findings of Stanior. ot aL and other investigators s T00 J5009 Federal Register / Vul. 4tL No. 215 / Friday. November , 1983 / Rules ond Regulations 51117 concerning the overruling importune* of flb*r dimension. Therefore. OSIIA will continue to include chemically ireaiad asbesto* longer thee 9 microateten with 3.1 or greater aspect ratio in the scop* of tko asboaio* standard. on tho bad* that chemically-traated asbestos poaaa a haqlth risk statilor to tket of uatroatad asbostoo. In summary. OSHA regards xporimoatal stadias of animals aa tuggestlng that all aabatloa (Ibv types poiMSt similar carcinogenic potency. Animal studies alao suggest that fiber dimensions rather than chemical properties or flber type may be the strange*! determinant of carcinogenicity. in OSHA's view. Extrapolation of the faults of experimental studio* in animals to the human experience necessitates so aaeumpboa that the flber dimensions used for experimental studies resemble fiber dimensions in workpieces. This assumption might not be valid la all instances. 4. Othor Fbctoro. The various types of abestoe fibers may differ in the percentage of fibers available tar inhalation and the length of lime that dust clouds remain amnia (Rowo. Ex. 44-04S). CroddoRte might stay airborne for a longer period of time sad have a greater number of respirable fibers compared to emotato. which in turn may excud anthophyflHa in retard re theu two choractoriaflu (Muir. Ex. 94-110). The preperatlen method tar chrysotfle will dstennlns theu'turn cheracteriettae tar a laboratory ueipis of chryutfle or for a pedicular workpiece with chrysotfle exposure (Rowe. Ex. M-OBgl. Beceuu thidcur fibers mifhl drop to the ground faster and croddoilte la generally finer than the other fibers, croddoliie uu might lead to dueher work enviroomeata and honu a psnr health risk, oven if aaddolite Is aal more dangerous on a fiber-for^Sber basis (bldr. Ex. M4M). However, mut respirable fibers, edtfch are tbs flbore likely to canu dteuaaa. win land to remain airborne far long sariode of time. Another point to mntariar is whether, for diilareat fiber types, the retie between fibers viatfile andara microscope and sltro-Ann submicroscoptc fltaan vurtu*. This would confarnd comparisons bstwaan cobars apparently exposed to the tamo Itrait of diOtrent visible fibers under the light micro* oops, if Indeed fibers net countsd by the prosut eptiesi microecopy method pous haxard re health (Muir. Ex. M-MO*. OSHA boliovu that thicker fibers are round in miatng and milling aud 'Jut lubscqucnt manufacturing processes 1 md to break fibers apart and rr-iuca iheir diameter. Based on experimental findings implicating long thin fibers es being the mut carcinogenic fibers, these subsequent processes may have a greater cardnogenic (retard compared to the Initial mining and milling operations (Nicholson. 1991. Ex. N4fl|, OSHA examined the quutioa of differentials far csidnogtnic risk among maaafactartng processes which fall under OSHA * jurisdiction. As is the case for studies of fiber type, crois- cohori coaiparisoas of processes should control tar the tallowing variables: fiber concentrations duradoe of follow-up. duration of expueara. and age distribution. To account for the variable of fiber concentration OSHA compared the potency (actors for lung cancer (KJ of difTsrent manufacturing studtea beesuu polency factors are besed on risk per unit dou. Aa discussed in Section V. QuaatiUtrrr RhkAjmiyria. the potency factors for lung esaaer were not consistently higher for any particular manufacturing process. Because potency factors for mesol,heliums (Kb) could be calculated far only 4 studies. OSHA could not compere Kg's lor difbraal manufacturing processes In summary, them does not appear to bo a coosiataat pattern of differential lung cancer hah by manufacturing process. Tharaforu. OSHA dssaw it appropriate Io continue to apply e single PEL to all ngmenta af industry oovurad by ths Agansy. ' Ralatfvuiy thick raantfubte Hoars tend to letfgs in iha hag wndn thinnar flbsn can travel re the periphery of the king, and pmauute and than redes in the pleura. These fine fibers lodged in the pleura might be the inducers of mesothelioma (Nicholson. 1901. Ex. 94an|.Blgnan(tel (Ex. 94-109) sludisd the lungs end pleurae of shipyera workers. and mend larger fiber*, specially, amphiboles, in the lungs, la tbu piaurua. fine and small fibers, usually cbrysotlia. were found. in summary. OSHA recognise* that the fiber types may differ with regard to thair tendencies to break into fine fibers. CraddoMte appears to dhrida into finar fibars mart readily than other asbesua flbar type*, which may render it mare hasaidnus. Manufacturing proceiaea ntittld breraeae the carcinogenicity of asbeetoa by generating fibers that are thiaaar in diameter relative to mining and milling preserves. While thssu factors on internating and contribute to the fsrmotion of hypotheses regarding the morbaniii of ssboitoa curctnagsnssis. OSHA believes that these (actors do r.ot provide a definitive answer to the question of possible differentials in risk by fiber type. OSHA views the data from epidemiologic sod rtpcrimcnlu! studies. which hate obaarvad excess cancar risk from exposure to all asbasioa fiber types, aa being the most important with regard to tho Question of differantial health risk by fiber types. 1 TrrmoJitt aadAjuhoptiylliu. Sum* bai not aB commercial tote deposits contain ssrpsnlino asbesto* and fibrous amphibole asbestos, inefuding chrysotilo. trsmoilte. and ontbophyllite |Dement sod Zumwald*. Ex. 94-039). Kleinbid *t si (1992. Ex S-iai) riudied tb* proportional* mortality of 220 talc miner* and milters in New York State who bad boon exposed to asbeetoa contained in tele. All men were employed during 1940 and bed IS or non yean of exposure during 1MO- 1991 Of91 daatitt bi tha study cohort 10 (11R) were from respiratory system cancar sad 29 (31*) wars horn pnaumoconiaaaa or complications of puoumoeanioais. KMntald at *L calculated that only 19 (12*) deaths ' from respiratory system cancar would have been expected, resulting in a greeter than 3*fald risk of respiratory cancer. A follow-up study by Klsinfstd t at (1*74. Ex. 94-141) included 260 workam exposed to asbestos in talc Of tha 109 daatha abaarvad. 13 (12*| were from raspuetory cancar compared to 4 (37*) expected Tho high proportion of deaths bom pneumoconiosis may have reduced the number of do*the bom lung cancar. Khduote *t at (Ex. 99-191) and Nurmiaan at at (Ex. *4-141) obaarvad pneumoconiosis and excess lung cancer mortality among Finnish worker exposed to talcs containing fibrous aatbophyUita and fibrous tremollte. No daatha from mesothelioma were reported by these investigators. Yaxidogiu. llcayto. Beict Seyli. and Yoruimax (Ex. 94-211) reported a high prevalence of ploutal caitdfication sod thicketdag end a high mortality rate irem aesothoiioau among residents of Cermik. s town la Turkey in which thetd " ' rs many dapcelte of aabaatitaan <-n nunareii which are used as ccnatrucboi^o material*. Tha coaatructfoa materials have ben shown to contain fibrous q uumoilte. sndgarile. Uardlte. chlorite, sod talc. Yaxtctofia et a), also reported an excess of hreq cancer In thin population. Brown. Dement and Wagoner of NIOSH (Ex. 94-023) conducted a Sietencal prospective study of talc miters end miUsn of one eonpsny in New York State reported by `Jit company to be mlntr.g talcs not containing asbssios ncacrsls. NICSH (Dement and Eurotvside). -towexer. nad raponed aibertcs exposure in the talc ooi s : y 31111 Fdwl Bcglrtur / Vol. M. No. 313 / Friday. November 4. 1903 / Ruin and Regulations mm* end mill NIOSH conducted M industrial hymen* survey of iho study ulc mint end neighboring talc mint known to contain aabaatoo fibers. Silica exposures wara found to bo vary low. wad baiow NIOSH-s raconunandcd PEL for silica. Radon daughter measurements modo by the Mlno Enforcement Safaty Administration (MESA) sbowod only ad to trsco levels. Oemant and Zumwaldo found that exposure characteristics botwaan tba study mint and neighboring mint wan substantially similar la fact ibt atrbonw dual itmplae hum the nina sad aUU studlad by NIOSH aad maintained by tha cempeey la ba aabawaa free wwu Isund la eaatato a hifhur pnapecHoa rf peetUvely Identified teOetttiarm aamhibaiaa largely dua w a higher twawllta Boataot All adwr fiber charactansbca. audt a(s| madlaa length diaawwr. sspaal rmtta. aad prusarttaa laaa thaa S fw w length. wara not atattaifcaily dtffanm at tba OS lavaT (Ex. aa-lOU p. Ml lit NIOSH study cohort (Brown at sL| consistad of all wblta males employed aooiatlina during 1M7-1P80l Vital status of tha sat cohort mambtn wss determined as of )uao XL 1BJI Coapariakn was modo to ago, calondar period. aad couoa aporlflr mortality ratoa ofUS wblta maloa Significant incrtaaaa in Knag caaoar mortality (g obaarvad deaths versus 3J expected) and non-wallmtonl respiratory dlaasaa omrtallty ( obaarvad varans 14 expectad) wort obaarvad. Ona daatb bum aaaothafioma occurradL Slnoo dm iodivtdual who dlod from maaothallnma had praviously worked la the construction industry, bio daatb oooid not ba dafiaitaly aacribad to bin exposure to irainollt* or anthepbylllto. Of tha to Individuals who diad bum raspirslory system cancar. 3 bad pravioualy worked for other New York State talc companion. NIOSH (avaattyotorAloa oddraaood tha potential confounding affactaaf ofarena sateking. In thair ogWom a cobar. of hoavy tmohoru would hove aa dor thaa a 4R* iocraaaa In lung eunom risk is raUooa to ail U& wblta maloa. Because they ubssrvad a muotor inornate ia lung cancer rtak. ctmaal a * [old risk, `hay judged that rigantm smoking waa wtlikaly to cccmml for tba obaarvad excise hum cancar risk among these talc minan and miliars sxpored In ' asbeetoa. Tha cross sectional morbidity survey eooductad by NIOSH in 1S7S fond a 4fi* pruvaianea of smoking a pmvakoco timflar to that ofl'J. malao Bruwu. Dement, and Wagoner ttatad that "exposure* to aaboatiform tremollta sad utthophyUit* stand out as tba prime suspected atiologie factors- associated with tba observed encase risks of lung cancer and rrspiratory disease. They concluded that "exposures to talcs from tha Gouvcrneur muting area are associated with aa increased risk of bronchogenic cancar and non-malignant diseases of tha respiratory lyatem- (Eju M-tni Aa measured by optical adcroscopy. average air coocastrations of fibers grastar than 3 tun ta length ranged from LT f/cc to Mf/ccaaaai hour tins#, weighted avenge for diffprant job tides ia tba mine, la tba odtL average air concentrations far mob fibers ranged bum 14 f/cc ta 14 f/cc as aa a- hour timu-wsighted average tor U dilfarasM job tide*. (Ex. S4-1l. pp. 7-10). In addition to the axoaas mortality bum lung cancer sad non-malignant respiratory disease obaarvad by Metofeld at al aad Brawn at . aumasuua studies of talc minors aad miliars exposed to sabeatas contained ia take have establishad that these workers kave high pravalanea of pleural thickening, pleural calcification, daaumeatt la pulmonary function. aad Obraaing lung disease (Dreaasan. 1933s Dreessea aad Della Valla, ink Siagai at sL 1M Schapara and Darken. IM; Masaita at sL 183* Kkiafald at aL 1903. ink ink ink me. ink rarat Moorman at aL 1974: KJvihtoto at aL UH Ahhusn at aL Wh Parra et al. me Ex. M>Ull Many of theae studtra wara oonductad in tha same geographic ana as tha studies by Brown at aL aad KktafaldataL A rruaa spelloosl morbidity study of the same company whose mortality twnartsatu waa studlad by Brawn and colleagues waa performed by NIOSH investigators (Gembk. Fsllaar. aad DeMae. Ex. tt-ltl). Aa dtocuased above. NIOSH considered that this company-* workforce waa expeead ta asbestos oaataiaad wtthm talc. NIOSH obsmvad markera of aabaatoa exposure ia tba hags of thaao workers m addition in respiratory symptoms and fasng taction decrements. Of m mak miners and ssiSotk 121 partidpaiad In tba survey. Respiratory questionnaires, cheat X-rays. aad spuumatrie taadng wars admirriatarod ta partkipatiag workata. Compariaoa of nspiratory morbidity waa nsada to W7 coal ouaara. ion potash ulnars, ebryaotlia asbeetoa workers sad synthetic wool textile workers. OSHA considers that one of the aujor atnngtba of Gambia at aL'a crass sectional morbidUy study waa tba -hoins of comparison popuktkna. Because tai& coaL rad poteeh miaon era Ukaly to ba similar In many conoccupational factors that may offset respiratory morbidity, dm likelihood of obaarvad difiatsncai k respiratory morbidity being Jut to specific workpUct exposures of the tak workers rather than other risk factors (or lung disease is gristly increased. Comparisons with tha coal and potash miners wara stratified by age. height., smoking status, and duratton of employment in mining. Cofliptfod 10 qdsJ fldoert mmI pouch miners, tha tak workers with an previous occupational exposure within other tak mines and mills had statistically significant incraaaas ia pleural thickening and a higher pravalanea of pleural calcification. Whan all tak worker* wara combined without regard to previous occupational exposure to tale, incraoaad pravalanea* of ruuA. phlegm production, dyspnea, pleural thickening pleural calcification, and Inagukr opadtios on the X-rays wan obaarvad in tak workers compand to ona or both mining control la addition, tak workata had significantly decreased pulmonary function (FEVl and FVCV Decreased lung function waa associated with incraaaad annulstlvs exposure* and lengths of axpesura. Tak woriuts had a similar pravalanea of respiratory symptoms wban compared to duysotils ssbestoa workers and a much higher pnvalancs of symptoms whan compared to synthetic stool toxtik workers, k contrast pleural thickening wss four > in talc srorksrs compared to tha chryaotik workers. Strum,waa not found to bo aaaodatad with tha obaarvad radiographic changes in tak workers. Regarding thsir studies of morbidity and mortality of workers exposed to tak containing ubastes. NIOSH concluded: "A (Sarawak review ot tha tvtiUblt Uteriisrs demaaeusiad thet fiadtags of tha praeosuradw* era ta apsemeut with those of other ratotae rt eecspaUoaai peas* expeead w the esaw w itaUlar mhwraleas mineral assess Ibt* i wprrirlty true far locapetiDnal irpnew is sathephyUita nhwwu Theae fladlngi auks U imperative that warkera bom the mtas tad mill studied. swvetaeea* arttaria attsMMwd la dw OSHA sad HMA measles standard. fwthamera. ahaagaam aea af thaa* takT (b. a*-,ML p. 331 StiOa and Tabanbaw (Ex. gg-tgg) of Tabarsbaw Oceupatieual Modlda* Asaocktos stodled all mak sraikan ampkyad anmatima damn 194g-lg77 at tha tak mint aad ndfl stamsd by NIOSH A total of TOP man statu ellgibl* for tha study, and vital status aa of December Ultra was ascertained for n af the atom Of tba rat man. S3 I GCSfiOOlS : fcdersIRcgitlor / VoL 4B. No. 2tS / Friday. November 4. 1983 / Rules and Regulations SI 119 workers were excluded because of lack of information on specific variables, leaving a cohori of SSI for analysis. Comparison wee nude to age. calendar period, and cause specific mortality rates of UX white males. For the overall cohort excesses la mortality that were not statistically significant wets observed for fat* cancer and nou-maitgnant respiratory disease. Stifle sad Tabenhaw jodfad that the non-significant excess of lung cancer was "consistent with a smokii^ effect" rather than an effect from occupational exposure (Ex. SS-19S. p. Oil. Stills snd Tabenhaw also separately analysed the mortality of the tale workers with a history of any work . experience before amplsymanl at the study mine snd arilL This prior wash experience tnchidod all previous (obs. not only |obs at other talc mines and mills. For this suboohort of MO while males, mortality from the following causes of death was significantly elevated: all cancan (SMRwlOt). liver cancer (SMR *1013). respiratory system cancer (SMJt-OS). lymphopoietic cancer (SMR >174). sod noo-malignant respiratory diseases (SMR m JOT). Stiile and Tabenhaw stated: "Since the cancan snd lung diseases typically have long latencies, the possibility exists that exposures prior to work at the TMX study onne end mill were responsible for st least some of these diseases" (Ex. S4-19S. p. set). When the mortality of the suboohort with no work experience prior to employment at toe study mine and mill was analyzed, oo causes of death were in excess. In (act the SMR for all causes was significantly dacraasad (SMR SO). As would be expected, this cohort was generally younger than tha cohort which bad previous work experience. Stills and Tabenhaw characterised than findings as fallows: (1) "Workers with 'exclusive' TMX [study atiaa end milt] employment seem to be at no considerable rise of having lung canon develop * and (Z) "axpseuraa at TMX seem to be nnnrarrinngaiUt" (Ex. M> 190. p. 403). NIOSH commented an SMBs and Tabanhaw's study (Ex. M-Ilt. p. 17k Ex. M-Sll lilting several prabfama in the analysis by Stiile and Tnbswhnw that could account for the different conclusion of the two sets of Investigators. Fins Still* and Tabenhaw failed te analyse mortality by length of followup latency tntsrvml). Brawn r. aL thought such an analysts was p trticuisriy important fives ihat ~ recently hired workers went allowed te voter the cohort as laid as one year before the study cut-off date for vital status determination. Second. Brawn st aL commented that Stilts and Tabanhaw's division of tbs study group into subcohorts with and withoot work anerionce prior to their employment at the rtudy facility resulted in "seiectian biases Inherent in the definition of the ssbeohorts" [Ex. at p. 179). The selection biases which landed te lessen tha statistical power of the subcohort without previous work expariann Included the short length of followup, short duration of expnura. snd small sin of tha subcohon Brown st L stated: "Any mortality analysis based on neb a small cohort with generally short latency is not Ukaly to be very informative" (Ex. M-Zlt. p. 179). Third. Brown et aL critidnd Stills and Tabanhaw's snalysas concerning tha deration of employment of the lung cancer cases. These analyses examined the observed hmg cancer deaths withoat calculating the expected number of deaths for each latency category and duration of employment category. In addition. Brown st aL pointed out that Stills and Tabanhaw's conclusions had not adequately icknowiedgod that many study facility workers had been employed by neighboring tala companies with exposures similar to thoao of the study facility. Breen et aL concluded that StiDe and Tabenhaar't report did not adequately address tha question of taaaasad lung caactr risk tram wnridag at tho study facility. In addition to the points discussed above. NIOSH also mmmantad that death cartifleataa should have been coded according to tha raise of tha 1CDA la effect at tho time of death and than converted to either the 7th or 9th revision of tho lOJA far inslysis, ratherthan coding the deaths directly to the 9th revision. NIOSH also had questions concerning tha S3 workers aiiminatad from tho cohori and how workers lost to follow up were treated la tho analysts. Tabenhaw and Thompson responded to the NIOSH oWque with the following comments (Ex. M-Z19). First they cited mineral scientists sad laboratories who diseased with MOSfs method of Identifying aabastos in siUcata minaret mixtures and who did not find sifiiflcaat asbestos concentrations in the tale processed at tha mine and sulL Second, they stated that talc ora at the tody facility was not tiaular to that of other tak tames of upsttia Now York. Third. Tabenhaw arid Thompson rmtsratsd that many of tho hmg cancer deaths occurred In short-term workers ampmyed for less than one year. In their rpinion, this lessened tha likelihood of the lung cancers being attributable to occupational exposure at the study plant. Tabenhaw and Thompson also pointad out that only one talc miliar developed lung cancer, despite the historically higher sxpetures of talc miliars. In conclusion. Tabenhaw and Thompson staled that application of tha tibfioi ttasdiid to tho Voodorbflt workfares erne unwarranted based on currant evidence. OSHA calculated a statistical power of 20% to detect a SOB increase in risk of lung cancer in Stiile and Tabershaw s subcohort of worktrs with no previous work experience. (See Ex. 94-330 for a dasatptioa of how OSHA calculated statistical power.) OSHA considers that this very low statistical power supports NIOSH*! criticism of the sensitivity of Stiile and Tabenhaw * study design. Th* statistical power would have been even lower if it had been calculated for tho group of workers with at Itast 20 yean of latency. As discussed tariiar. cross-cohort comparison may be problematic if the age distributions, durations of exposure, sod lengths of follow-up differ among the cohorts being compandT OSHA - believes that this appears to be tha case with TOMA's comparison of tho subcohotts with and without previous work experience. Several points are notable with regard to tho q--stlon of tho short-tarm workers who developed lung cancor. Ftm short durations of exposure may result to high cumulative doses dspending upon the intensity of the exposure. Second, tho phenomenon of short-term asbestos exposure and subsequent disease baa been observed in other epidemiologic studies. Third, d th* majority of parsoo-yeare-at-risk were contributed by sbort-tenn workers, than finding moat of the lung cancer deaths among these workers would not be unusual. Also. Tabenhaw snd Thompson did not discus* the expected " * number of bag cancer deaths whan they") mentioned th* single lung cancer desth--j among tho study facility talc miliars. ^ In 1903. Consultants in Epidemiology--, sad Occupational Health (CEOH) prepared another analysis of tha --' mortality of StiDa and Tabanhaw's <-n study cohort (Ex. M-2S7V NIOSH reviewed CEOtfe analysis and staledi-O "Although tha findings of these rsj analyse* appear to support their (CEOffi| hypothesis that tha talc is noo-carmnogenm. tha resulting statistical an(lyses era based on osfufflptfanfc small ruxben. and short Icltncy. Therefore, the CEOH condcaiont are based oo analyses that are inherently deficient in being able to 51120 Federal Register /. Vul 48. No. 215 / Friday. November 4. 1993 / Rule* and Regulations detect true risk to aa exposed conaietent with thoee of numerooa other population* lb. (WJl p. II studies. OSHA believea that Iht Smith, Hubert. SoboL end Uurquet epidemiologic study of tha talc company (Ex. aa-tMl atadiad health effects of tele conducted by SliUe aad Tabarahaw at cantMining eebeeioe hi labwolery Taberehaw Occupational Ibdidat nuneia. Smith rt aL edmltoalasad Aeaodalea has asttoos Uadtationaaach iatrapieafal tofoettone of 4 different trtmoiiUc sabetancaa toto hamsters, that H daaa not tafute tha bypotheaia mahmato# pa-- m indudins ffbmue traaolidc tabfrom fang caaoar haaara to axpoaad worker* New Yoth Mata, tremothe prepared from Sadlh at aL`a experimental atudy tmmoUUc talc om dr the facility etudied abaartrad poaiUtra findings of by NIOSH. tremplile prepared bam tuiaaripenlrity far aahaatlform talc and western US tmmelitic tote ora. aad aebeettfena tramoUte. Pariods ot non peoiMvo findtoga far the talc from tha facility atudiad by NIOSH: however. observation tangnd from HO daya to 800 06HA tbtaka that itodtaHooe ofSmith et daya after lafaeham Tumors aad ptoorat it's study lender ita findtoga 0broad ware nbaarvsd oaiy ta animals tocewdualva for talc from the facility Injected with aabaatffocm tratanHla aad studied by NIOSH. In any avonk the tramotite prepared from arealam UX positive human findtoga oatwaigh tha tremolitie tak ora. Sadlh at aL bead that tha aamalaa ofaabaattfarm MtauU findiflfia Tln cartabring aabeatoa minerals. therefor* irerooilte had greeter praeortlooa of tens appear to peso a significant health riah thla fibera thaa tha sample of tremoUta troa the facility stadiad by NIOSH. axpoaad workers. aad talc wotbara axpoaad to aabaatca ahouldracaivathe Tha aampia of fibrosa fremoiitic laic from New York atate aba caatainad loos thin fibers aad Sadlh at aL aiiijaetail that tha aagathro results hem thia particular sample warn dm ta tta much low* tremobd eeatwtfrajattre la pratoetton afforded by L'it aabeatoa standard. OSHA ootaa that the broader laaua aa to which mineral Oban am to be tnrladad to the definition of oabtatoo arilf be part of the rulemaking for the parmaaant ataadard. Thla Era aedaa doea not change tha defbdlioo of tusseaiad that tha aasrpia of tremoUta from the facility stadia^ by NIOSH mayhave tailed to ladaca tamora bocauao of tha ahaitar lengthaf fra fibom, dapptta aabeatoa aa found to 1910.1001. A.Summary. The evidence preemdy befom the Agae^ indicate* that afl fiber typaa. except far oa their leoelts aad oo the tact that tha coactnonsnic aamplaa oontatood oiaterial ether thaa tremeUtq Smith at aL rtaiwfc ~ * ** canoes to am* that thwr activity le due wtotty. or area la part ta tremoUta ' canaMamOee weal aa |Kraa. nol aatfr a the annual d Biiedile. bat lea to odwr lactam, auto m tha urptoietoa chaiecMrisucs of Aa wtoetsT (Es. SS-iat . MOL OSHA eonatdare that tolerpmtettan af Smith at aL'a llsdiiifa ta UmHad by the aataU aumbm of aatath stadiad abort funrteal times. end then pariada of observation. In summary. OSHA caariuder that NIOSH atudia* hatra (haw* that exposure to aabastae whoa it to] in taic appear* to have maaitad to excessi mortality from thuanssc1 ancer aad non-maligrant raapiratary dtaeaaa aad exetta rtak of pleural thickening and lung function deunsarata. OSHA ia cognisant of tha fact taat talc Titling rod m-lllng to tha abaanoa of aabmtaa axooauie can toaall la poaamoconinaiai Furthermore. NIOSH" BnrHnga oa mortality am oomatam wuh thoee af Klui.nfsld at aL Kiviluoto at aL Nurr tinea at aL and Yaakhtgto et aL MOSKt morbidity findings are reportad to anthoptnrUite workers. For tong cancer. OSHA notae that lAflMaktnl iMnsdailVft ft&dtilMfr with regard ta diffamadal riah by fiber type have been observed by difhmnt investigators. Soma stodtoa have obaarvad the aama or higher lung cancm itok toehryeotde workara compared la vtarhem axpoaad to omphlbolo fibans other atadtoa obaarve tower riah of king cancer to chryaotila workata For example, high reepimiary cancer rtak waa obaarvad by Dactaot aad cnitaaguaa among chnraadk textile work*.-*. Aa itiareaiad by CHAP. tenstotem pattaraa afbigbar hag cancer riah by fiber type dM eat ornery* With aeon axcapUoaa. tovaadgatora gsnemily failed ta cuetrot far vartobiot affecting tang cancer rtak when caaipartag the mortality af different occupational oohorta. Among the important drtsrmtoanta of lung cancm rtak. which warn not con*utrolly wntmHwl far. am fiber concantnttoe. length of obaerrattoa. and aga dfaWtattorn OSIIA rim rvidenca for differential BMaotbnUoma risk by fiber tyrw u Kffast.va yet not conclusive. Occut mortal cohorta axpeaad to erocidolita and amoeite appear to Iwve had a higher proportion of dee the beat metulhMioau. perticuleriy parilenaal mesothelioma. competed ta occupational cohorta axpoaad la chryaotila. Nonathatoaa. OSHA ta uaubiv to characterise this evidence ee cooctoatoabacauaamaattovaetigitora fslictf to oofllfoi frf length af ebtirvatiorv aad aga diafributtoa whan aufctag ctoaaophaw campaitoona of mortality from . mesothelioma. Controlling for length of observation ia psrticularty importaal bmunmMomiioaM iniUf 1mm latency period of 30 yearn or mom aad tha rtok rtsae exponentially with increasing Itowtones initial axpoaum. Luag caacar is the mafor causa of etortallly. Moaothaitoma and asbaatcaia alaaamajyiificant causal of axcaaa atortatoy among aabeatoa svorfcara. OSHA baa concluded that them ia a grave rtak far lung cancer aad asbeetools among workara axpoaad to ail aabeatoa fiber types aad that workara need to be protected from three risks by thia STS. whicheetsthelowastPa.thetir feasible at thla than. Aa a practical regulatory endpoint thomfora. It (a Inranaaonanttol whether tha maanthriioma risk is greater for cattain fiber types then brother types. tnarimemal stadias of animals ham fatad that duyaodla to as least aa potato a camtaogan as other aabeatoa fiber types. Ooe study found that chrysadla urea atom carcinogenic thaa ether aabeatoa fibers whan administered by inhalation. Many experimental studies have mpartod that fiber dimension to a vary important datamtoant of caictoogeuidty In laboratory animals, fibers longer than t eucroautots (on) and with diameters of lJum or leas have bean implicated as tha moat cardnoganic fibers. A variety ofdifferent natural aad aynthattd subatancaa basing fibers longer than i jm with widths of 1A am er leaa have inducad cancers via Unplaatation to laboratory "'"*! aimeating that tha chearicai proparttoe of aabaatoa (such a* fiber type] and non aabeetoe fibers may not offact cairlnnews'city bat that fiber cardaogenicity. Thaa. to OSHA'a view, animal atudiaa do not support the hypothesis that them am differences to carctooganic potancy eating tha varaus fiber typam Ftoor typos may differ with reytro to tha finanaaa of fibom aaod totodustnal procasoaa. floor fibom may bo mors carctoogeote. according to animol studies, aad cracidoUtt appears to be divided mom readily into tine fibers : STOO35993 Federal BeaUier / Vol. 4*. No. 213 / Friday. November 4. 1983 I Rules and Regulations 31121 than other asbestos liber types. Alia manufacturing processes may break fibers sport to generate fibers thinner in diameter than those (band in the mining and milling prnraiaaa NIOSH scientists (Brawn. Dement, and Wagoner) observed excessive mortality from lung cancer and nan- malignant respiratory disease among workers la ena plant exposed to tale containing asbestos. A morbidity survey of the seme plant found Increased risk of pleural thickening and lung function decrements. NIMH concluded that increased risk of lung cancer and nanmalignant respiratory disease was apparent in workers oxpeeod to talc containing asbestos. Kkinfsld and colleagues also abunrsd excess lung cancer and respiratory disease SMrtaiity smong workers exposed to talc containing asbestos, and numerous morbidity surveys have documented respiratory disease excesses among talc miners end millers exposed to asbestos. SUlle and Taberahaw conducted study which they interpreted as contradicting NOSH'S findings regarding excessive mortality among talc workers exposed to asbestos. Stifle and Tabarahaw't study had sarieaa mathodeiegle limitations such that NOSH'S conclusions still appear to be valid. While not all talc product* contain asbestos. OSHA Bad* that whan asbestos minerals art contained in talc products, than appears to be a health risk to exposed workers. Practical administrative considerations also an pertinent to tbs question of making regulatory distinctions by fiber type. Several types of tabestoe may be present in the same workpiece, as ia the can for insulation, creating considenbie measurement difficulties. Determining asbestos lypafs) within each workplace might compttcata compliance and exposure monitoring. However. OSHA Is awan fruit the United Kingdom has bean able In overcome each cempBcatlana la summary. OSHA concludes that on the bast* of the epidemiologic and experimental startles reviewsd above, it is not appropriate at this dm* to auks distinctions by fiber type for regulatory purposes. Accordingly, quantitative analyses of risk should bon setiauto* of excess risk on asbestoa fiben as a whole rather than on separate fiber type*. Provisoes of OSHA's standard for asbestos, including the permissible exposure Unit should also be the sama for all eoamarically used asbestos (that types. F. Coi.-JtaicM At'.iestos poses a grave danger to the health of exposed workers, having caused excess mortality and disability in epidemic proportions among some groups of exposed workers. Asbestos causes non-maiignsnt respiratory disease, which can result la complete disability and death. Asbestos also causes malignant mesothelioma, which is usually rapidly fatal, and lung cancer, which is usually fatal. The causal relationship between asbestos exposure and disease has bean ssubUshad by a multitude of epidemiologic studlee conducted throughout the world, including the United State*. United Kingdom. Canada. Australia. Italy, and Finland. Furthermore, asbestos has bees shown to cauoe txesss disesss la many different occupational environments, itarting with muting and milling of asbestos and continatna to causa disease In various manfactortag processes such as asbestos textile production and asbestos cement production. Asbestoe elan has bemi shown to be sxtrnmsiy haxardous urban used as a product by insulation wotkare usd shipbuilding workers. Numerous ctentiae ofyufxsttatt --^ A|nciM have reviawad the health data far asbestos and have concluded that asbestos exposure causes hug cancer OMSttthfttioBAi To determine the potential of a hatardoua agent to cause diaaaao it low exposures. OSHA has examined the result* of studies of workers receiving low exposures. sshere such studies are available and have sufficient sensitivity to 4*tact excess risk of disease. OSHA has also attomptod to predict risk at low exposures from dak observed at high xposuraa by using does sxtrsuulstton models (saa seetton V). Both of three methods of evaluating risk at low exposures are valid. Studies are not available of werkan upend solely to asbestos levais of 2 f/ cc whichhave suffident cohort sist and long snoagh fellow up periods to permit absstvatien of increases to cancer and hmg disease mortality. Studies ere available of wetkew with low cumulative exposure* to asbestos, however. Wotkare exposed SO yvtrs to the OSHA PEL of 2 f/cc would have a canalsttra exposure of 100 f/oo-yean. Hsnoa. stadias of workers with niaiulathrs sxporeres does to or below 100 f/cc-ysurt preside soma evidence of risk from working lifetime exposuna to OSHA's PEL Studies finding edvane pulmonary affects or exrasaivu aartaiity from hmg disesss burn exposure dose to or balow 100 f/c conducted by Batty at aL McDonald at sL. Damant at aL. Berry end Newhouse, and rUwsIsUin. Dement at aL. FHsk.jUtra. and Henderson and Foteriine also observed excess irortslity from lung cancer smong workers receiving relatively low cumulative exposures. Wmll at aL and McDonald st aL did not observe increased lung cancer mortality among worker* receiving relatively few cumulative xposuraa. Despite some inconsistoneiss in fiadhtp regarding risk bum m?w- cumaiative exposures. OSHA considers that the many well-conductsd sfudJsa which observed substantially Increasad risk of morbidity snd mortality smony workers receiving few cuauletive exposures era evidence of signifies** hazard st exposures alfewedby lb* existing PEL Section V,, QuantitaU .* Huk Ajtaiyta. will discuss predict** risk from exposure to OSHA's PC A nuabar of investigators bare suggested that different fiber type* of asbestos hare differences in their ability to induce mesothelioma: Specifically, aocfdolito has been hypothesized to be the most hazardous type of asbestoe because of suggestive evidence that indicates that tha mesothelioma risk ay be higher far croddollto exposure then far other asbestos types. All eommufriully used fiber types have induced hmg cancer, mesothelioma, sod asbestos!* in sxpeasd workers. excop* fas anthophyllito. which has induce** hmg cancar and aabeetosis. OSHA regards evidence far differentiate b> fibre type in lung cancer risk and aabsrimda riak as being inroadusivv and Incanristant However, evidence for fibre type dUfsrantfala ia risk with ^ regard to Induction of mesothelioma. --U particuiariy peritoneal mesothelioma. cz> appears to be more consistent based an-, epidemiologic studies of occupational , -, cohorts ixpossd to different fiber types _ Bscsuse vsrisblss that affect the sensitivity of studies for detection o< 4-3 riak of mesothelioma have not been *-3 cootrolled far by moot investigators -c* compering different occupational cohorts. OSHA views the evidence for fiber type differential* in mesothelioma risk as Inconclusive. Among the variable* that influence the appearance of mesothelioma ere length of observeboo. duration of exposure, fiber oancsnBarton, end spa distribution. It la possible that maaothalloma riak may ba higher from exposure to flare fibres, ana that operations using ooddoltta any tend to break fibers apart to make than more carcinogenic. Stadias in laboratory animals have net coaaiatontty abaurvsd differential riak by fibre type erith regard to induction of pUmooary fibrosis sad cancers: in fact, some studies m animals have found chrysotila to be the most carcinogenic among tihe various asbestos fibers testae 3U22 federal Regisfse / Vnl. 48. No. 215 / Friday. Novvmlter 4. iwt3 / Rul<- r.i R<tgtil.itions t.ung cnncer I* Ih# major cauir of "bMioo-aatoctalod occupational mortality. Tha vary high risk of King c.-.nccr (ram exposure to ad aabaatoa fiber types auppoats dtoosiog the mow IH (or all fiber types. Several epidemiologic stadias, including one performed by h'lOSK Kara found that workers exposed ta talc umiainlng asbestos haveexceas murulity from lung cancer and non* mutigaoi respiratory disease. Many other studios have observed excess moiliidily Tram respiratory disease, chest X-ray abnormalities, and king funuion decrements among suck verier*. One noa-pueitive study conducted by SMlle and Tsbesahaw at talc workers has msthodofagk limitations such that ITdoes not refute ttudies finding eerase mortality amoos workers exposed to talc coomimag abasias. A ouabar of studies in Isbontory animals has* implicated long dlia asbestos fibers a the etiology of cancer ad lung fibrosis. Stanton et ei found that fibers graslar then 4 yum in length and 1J tuner Isasla diameter war* the most carcinogenic however. OSHA believer that Stantou at aL's studies do not exdude the possibility of cardaogsnidty of fibers shorter or thicker than these rttmeustrum At least 12 stndfos base observed excess mortallly bom gastwdoteitlnsl cancer (slomacb. suophsgus. cetoc ead rectulnl smaag asbestos iipneed workers. 7 of which found statistically significant sxrssaes Other caccar sitae have alas bean observed to be maiesud by dlTTttaai investigators. OSHA believes that Iks partrive htmisa snaliss finding gasuointMiiaal caarar sxrassss outweigh the non-positive and equivocal animal studies of iogsatod asbuaioa. as well as the sow pnrtlte* beam* stiidlas Therefor*. OSHA rimclndm foot oxrass mortality (ram gasMatsadanlcsaesr should be Deluded tai qeandSarivc risk analyses for tabsSODS. Gpaiette rasoka sad ssbasms hero a muiupllrativs (aynwgtoric) rfsm with rsgofd -o production of brag esurar. Asbestosw also tight bs iaersesed ia cigarette smoking asbestos wcilmra relative to oaa smoking asbestos workers OSHA a eat swore of aey evidence far an effect of dgerrWs smoking on iadadiea of msselksllsmsi or ynstmtatosiiaal msllgneneka among asheslas workers. Ilemmend et aL found that both smoking and mem'making asbestos insuladen workers ned rel itive risks far lung canryr of jIk-ui 5. V. Quantitative Kink Analysis .4. //t/rodut-'oe As explained above. OSflA's determination that currently exposed workers fees grave risk of asbestos* -vistad dlsesse is primarily based oe the results sf quantitative ribfc assessment performed by the Agency. Hie proceee of sunning the risk bom asbestos exposure includes several steps. OSHA hat critically evaluated tbs acientific vidsocs ceeccrntag tbs health risk bum arisottos exposure. OSHA. as well as other eoetuific groups, believes that utmifli iipoiffi cmmi )ufl| rMpireiory cancer, mesothelioma, and gsstromtsstmsl cancer. OSHA baa also examined (and discussed in the aoctioa ntitlsd SpidemoJogic Erideoae ee Risk from Etpneum at Current the PEL. . Section IV&) evidence diet indicates (bat mama dtossss risk has bees observed at camsietive axpoaena atce below those permitted by the existing OSHA hoar permissible exposure limit (a addition OSHA has mads risk astimatm of axcats mortality bom hmg cancer, maaeth ill sum, gsstraiaissltnsl center sad Inddenca of asbestoek using mathematical amdaia that describe the data abeaevsd In epidemiologic etedles conducted in varietm foduatriaf wpwsmyiniJmnnliniemnnw is many easostho elevated risks seen la worker popnledons reflect past exposures that were hfgbss than those permittedtoday. OSHA'i quantitative tfofc eeieeement euUile vising the direody observed risks bom these past expoeurea to eetimese risk at lowes exposure levels. OSHA believes this is a sdentiiTcany appropriate and valid procedure. In sums instances. OSHA aehmstad riiks using etudfoa which actually observed risks at or below ramuUdve exposures peronttad by tha oarent standard. The nape at atudbaa eevara many different work situations and exposure levels upon which ta base tbs extrapoiatioaa. When passible, OSHA has quantified tbs ranges sf encanaiatias in tha estimates These auawriral estimates as wall as thraa risks abamvad et law exposures were evaluated to determine tin aignillceiira of the risk and la detatnuae whether the smndard will lead to a substantial redactioa m rtok. The xecheee below provide a brief r-eopala of OSHA'a quantitative risk esiimatea derived bom wlfcsmalirol amdaia. A Tcrv detailed description of OSHA'* calculations for asbeetoo* related raacm Is ia the public docket and ia avaiblib- upon reqi-esI (Kv ga ff. Dote-Rrtponre Modrl for Loaf Cancer Oose-response mformatioe for fong cancer based on the spidsmiofogfool studies mdkatee that the risk of asbcstos-iodeced long cancer increases Uneeriy with dose. Therefore. OSHA believes it is appropriate to ass e mathematical modef which seenmas that the excess risk is Urnsriy proportional to doss to estimate tha excess mortality whtt ia associated with asbestos exposure. This exesea risk is expressed af the number of additional lung cancer deaths per 1000 worksrs eaposed for specfflc time period. Excess risk equals ihs cumrtativ* doss multiplied by s potracy oBsffcfsnt (slope of the deeo(sponso curve) estimaiad bom the studies. (Note: Total dose, also referred to as cumulative exposure or cumulative doe*, la a meeaut* of the amount of asbestos inhaled: it is tha product of the duraboa of exposure (in yean) sad the fstetutty of expo*an (which ti workplace an concentreHen la mppcf or flbers/cej. Under this dsfinitton.cf exposure, a person sxpoaed to airborne asbestos at 2 fibeis/cc far 80 years (40 fiben/ec-yesn) has tha asaw total doss a pstson who is sxpoaed to asbestos at 4 Rbsn/cc for 10 yean (40 Rfcars/cc- yamslj: Irtrtewe of the Basse doss response relatfoosbip for lung cancer la found in wversl waU-cooductad epidemiologic ttudies that evemlimrf lung rancm morality iarelation to the cumulattve asbestos ssposme in tbs workpiaradfar ---Fm.rlir^ vora Ex. 5-tn Uddsil at si- Ign. Ex. 54-Me and Osmsnt at sl_ 1011. Ex. 04-39). te tbs thrso studies atod aoove. workplace sabestos an eoocsainUoos warn vsilabls bom mssainemsels made to the worksiu aludiad. Although the studies differ ia the maenads of the risk fouari lillennaed latoc to the section), all due* demonstrate a linear relationship ovar the entire range of observation. Other scienttots and adastlflc group* wbe bane attempted to estimate risk (ram asbestos exposers have used the linear model for limgraarar (Crump Ex. IMI Mtish Advtoory Ccoumttte on Asbestos. Ex. 84-218. Achaean end Gardner. Ex. 04-243. Sellkoff. Ex. 42-2: EPA Ex. 44-180. CHAP. Ex. 44-230). THs model to generally eccaptec end OSHA believas use of the linear sandal for predicting long cancer due to asbestos exposure is ressenabts tod svsUaupparted. Relative risk is dafined as the ratio of he mortality rata of exposed persona to :h<t mortality rate of equivalent non- ST 0 0-0 5 9 9 5 Federal Bpgistar / VoL <&, No. 215 / Friday. November 4. 1M3 / Rules nnd Regulations 51123 exposed persons. Relative risk is frequently approximated by dtp standardized mortality ratio (S.MR), which is the observed number of deaths in the exposed population divided by the number of deaths that would be expected in the exposed popuJetion. The number of expected deaths is usually derived from the specific age. sex. end -'tnder year mortality rates in the comparison populetioa. Based upon the considerations listed sbove and on the data, the relative risk model used by OSHA in assessing the risk of developing lung cancer from asbestos exposure is described by the following equation: *1 ** * l*(. * 1 1 VlO^ Tnet ts. \ * * * t.|0 (Eq. 21 Mrs 8^ ts the lung cancer aortal tty resulting froo the assesses exposure, kg ts the expecteo aortality >n tne aosance of exposure, f is tne intensity of exposure in fioers/cc, a is tna ouratian of exposure in years, t is tne tiaa froa tne onset of tne asoestos exposure in years tatnus lb years to allsa for-a ainiaus latent perfooi ano k^ is the proportionality constant tnet is a aeature of tae carcinogenic potency of tne asoestos exposure (Slope of tne oose-rexponse curvet. (For a nort oetattod rationale for tne cnoice of this aooei, see Ex. MOM). Tnis calculation ues porforeoe for teca fWe-year age interval; the overall lung cancer rise is then ceoputee as tae sun ef the risks ta seen of the ftve-yeer intervals frqn age 25 to age 70. ! ST00 J599G The coaospt of direct peopgtiowaHty of the rick ef hang canoer to the doaa caa be damonsotad with a aixepia example Using Equatioa 2. U doee is ingassed by a fecig of three, such os incroaeiag the duration of oxposara from two yoon to six year*. the exrag relative risk ((V/ R*)- 1! risk ingeeeg by a factor if three. Also, reducing doso by radudng sir concentredona, such m from 4 Bbar^ ec to 1 fiber/oc. todgoa the axcog relabve risk by a ferig of tow. |H should be ooted thee dm gtimetoe of risk green to Tebtg 10 and 11 era sstunatg of reraw risk, not txoag relative risk. Therefore. ding proportionality of dog end risk an described above may oof bo observed. Further explanation is given in Section *1 C Oxe-Agpong Afodbffor ' AfeaorAetiomo OSHA believes that the risk of mesothelioma is best cetin-tied by an abaohite risk model. Abaoiole risk lo among o eohost of factory worker* m calculated as (observed deatha/pamon- England. United data era also available yoonat rUkL Use of SMR'e g relative from three stodig oc the dog response riak is aot appropriate for maoocheUoaa relationship fg mgnthellome (Seidmaa boeoug the expected nombg of deaths *t aL lBTBi Ex. 84-87: Hobbs, el aL WBO. la a cohort would bo dog to xero due to Ex. 132. and Jones at aL 1900. Ex. 84- the rarity of the disease. la additian ta 134|. using abaotote risk rather than relative Tha data indicate that owrtality from risk this model is different from that _ maeotheiiooa beghta to iamoag only ueod for hmg cancmr becaeg both aftg a minimum of tan yuan following dorotion of time lines initial expomno tha initial exposure and bagina to and durstton of txpoauro are dacraag aftor 45 yean from ongt of detaraiinebve risk The magnitude at the exposure tSaUkofl at aLUTBt Ex. 84-80 * risk btavegi lineariy with iataaaity of and Nlcbolaoa at aL 1983. Ex. 14-2311. exposure, wharau the nek iacraaag Tba mortality from ataenlhsllonta can bo exponontlally with duration of axpootoo and lima from onset of exposure. daacribod by tha following equations (Equation 3). The ndoaaio far each a modal fg describing meao'.behcma risk hg bean diacmead by several aethors (Armitaga and DoiL IM. Ex. M-2S2; Mke im Ex. 04-188). Such a modal so utilized by Newhoag and Berry 119TB, Ex. M tu| in psedieting mescthclioma mortality 51124 Federal Register / Vot. 4a No. 218 / Friday. November 4. mm / Rule* and Regulations I il| lit I0|J (t-lO-4)Jj . AX,, f i Aj it-ta)* for lXIO'4 for lu*s>t2IO 6 for IO>t tf|| K tM sorttilt/ tram astotholioas, I 1| IM latMtttjr Of umwf to fIMrt/CC. II IM MMIW of UtMn /tort, I it tiao after first nMtofl in /Mr*. M 1^ is IM rgMrtiMlll| constant imi is * mium of tae mwimIiim careinogun ic potency (sloe* of Mti-niHnll curve) (to. *4-142i. D. OSHA't Quaautatrro Mlmt AjmimmM OSHA't critical svslustion ef til relevant animal and epidemiological studios resulted la leloctloa of tWvea epidemiological studies tor calculatkm of the Kt tor long cancer (Selikoff el sL 19J*. fa. g*-k Seidaaa el aL ItTE b. *4-07: Headatsoa aad EntarHaa. 1979k Ex. 04-4* Waill at aLOTVk Ex. 04-3091 FlakalstataL 1999k Ex. 94-9t0t Peio. 1990k Ex. 94-lOOe Dement si tL 19K. Ex. M31c Barry and Mtwhoess. 190. Ex. 94-93: Lidded at aL 1977. Ex. 94>49c Nicholson et aL 1979k Ex. 94-70 aad Rabiea at aL 1979k Ex. 94-49) aad fear far Ku far mesothelioma fSsUkoff et aL 1979. Ex. 94-90C Seidmaa et aL 1979. Ex. 94-97: rnkaktata at. sL 1991b. 94-34* aad Pete. 1890. Ex. 94-199). la geasral. studies ol htunaa cohorts in the workplace should provide a better basis for quantitative risk populations el hah and the populations from which the hah ratimatas are derived, la determining the potaacjr eoailidaata Kt *ad K Equations i aad 3 warn used to define the rinse response reiatlensktp so that cancer mortality eras estimated lor various exposure levels aad exposure durations. A number ef wsi mnduclsd end high quality epidemiologic ttsfiao were available that aaatahmd aofWrisal information on srhkh to base a quantitative risk assessment Some of these studies did not contain eaposein data, but could be coupled etith exposure information from other sources ir order to obtain an estimate of Ki and E* OSHA chess act to use snimai stutfiaa to predict cear.tltalive estimates of risk from asbestos exposure duo to the away high quality human studies that exist that were conducted in actual workplace situations. Rather 051 (A has supplemented the human dste with results from snimel studies in the valuation of the health information and in the dotararinatioa of the ligniflcancs of risk because OSHA believes that tbs animal studies provide valuable qualitative information on ssbeslos- raialod diaeaaok It is not dear ia all instances whether laboratory anunaia have baas exposed to fib* tarn distributions similar to thorn found in workpieces, la addition, asbestos appears to muhipiy the underlying lung caacar risk of amattag sad nonsmoking workers: laboratory animals gonsraliy do aot havy aay endariytag risk for davaloptag hmg cancm However, the oimai studiee do show that al coaemarcial aebssloa types caa caeaa caacm aad palmnaary fibrosis. Animal stadias also iacUcsia that longsr. thiaam fibers may have graatm caranoganic potency than short ooom fibers. The range of eetimatae of risk from the eleven epidemiologic studiee is rather large. His differences ia results asuing the studies can be explained in several ways. There appears to be actual diCerances ia risk depending upon the nature ef Ike asbestos exposure One potential explanation ia that workplaces dtffar with ragud to fiber stas dhtitbetieaa (longw flam fiber* appear to have yeatar cardaoganic potential than the ooarae flbank Tba observed Ki values far stadias ef mining and milling operations, where aubsme fiber* an relatively coarse, an lower thaa ths IL vUuas found in stadfas ef textile upo.-ulioes wksra fibers are fins. Diffu--nese may also bo txpiaiood by the vanatioM in study design and other (acton Influencing tha ability to dated risen risks. One of these is the Untiled knowledge of pus: fiber expoeura* of thoer populations wbueo mortality we* later evaluated. Prior to 1970k few mroturamrnis won made in facilities using asbestos fibers. Further, those measurements that wort done usually quantified all dual preseal in the workplace air and not fast fibers. Carnal techniques, srhkh involve use of membrane (filers and phase contrast microscopy for tha counting of fibers longsr than five nticromstars have bean utilized ia Great Britain sod the United States only since 1964 (Ayer at sL 1999k Ex. 94-9S3;| and have bam standardized in tba United States only titter 1979 (laideL 1979. Ex. 94-92) and tven latar in Grant Britain. In any case, sampling hat occurred only for few worksites and then only occasionally. OSHA has evaluated these dilfsrsncts and have dealt with their implications on a study by study basis, as explained ia tha quantitative risk assessment (Ex. 94392). OSHA notes that daapite these apparent limitations, token as a whole, the asbestos stadias contain data of unuasaUy high qoaUty which hat enabled OSHA to maks the risk tttimatas with a high dagrao of confidence. In addition, variability in work activities and in sampling dmimatancss odd considerable uncertainty to knowledge of daaa. Some of the epidemiologic studies, including those by Dement at sL (Ex. 94- 39|. McDonald at aL (Ex. 94-Uk and Hsndancn and Entorlina (Ex. 94-49k bat* mssssrsd sir concentrations at ths exposure sits aad used fob histories of the study population to estimate exposure, la thasa cases ths doesresponse curve was calculated by aafiting total asbestos exposure (ia mppef-yoars or in fibor/cc-ytsis) according to tha time that an individual spent st a fob with a msasund exposure value. A conversion factor for converting from mpfxd to f/cc was smpioysd an a study by study basis depending upon the data available. Other apkiaminioycal stadias, for example those by Ssiihoff et tL (Ex. 9490k Ssidman st ak (Ex. 94-47). had auithar fob histartoa nor dlract Industrial 'hygten* moomiramontt for tho ttudiad worker populating For thasa studies. . exposure sstimatss wars darivad from industrial hygiana larvays of similar wofk operations and pnmim fot which industrial hygiene data wart avaifabla. Tha study by Ssidman at sL bnwaver, confined goof information mgntding duration of oxpesuro (which can often bo oxantinod aa a surrogata for doao la asubllthing tha shape of tho xpoauro-napooM relationship). Aa discussed in Section IV. OSHA has cnnthidsd that worker* exposed to ' S700 J5997 Federal Register / VoL 44. No. 213 / Friday. November 4, 1943 / Rule* and Regulations 51125 ' ST000.5998 *bestoa an likely to bo at on inersssed or in aotne case* statistical risk of gastrointestinal cancer. Though uncart*mtias associated with small a excess of Ct coieor bu oat boos number* Detailed derivation of each observed consistently to every study of range of uncertainty la dlacntaod in Ex. tboatoo worker* oaf while tho ratio of lostrotfitooitooi caacar to luag cuat The disdacl aetaroef mtafaif-mitUay varioa considersMy boot study to (tody, data (and hewoa. the estimates of Kt there sMeen to be sufficient evidence to roofUy estimate tba excess boa theee data) hero beao considered earlier. Then to eosM evidence that gastrointestinal caaoer risk to asbettoe> riake to the aaheetos odatotadOtog exposed populations, la ftsaral tba riak operoda-- an lower fata other ranfoo boa abort I to IK of tba excess Industrial operatiooa doe to differences lung caacar riak. (A detailed lobloof tba to fiber eta* The* to detemthdag the risk boa gsstrotoiesttoa] esneor best overall raise far Kt from thasievaa observed to tT stodtoi to given to Ex. 44- atadie* the date wan axaadaed both 392k la attempt to quantify tho riak of with aad without tha Kt caicuiatod Boa gastrointestinal cancar. OSHA eonaldara tfui upditi of nfrrtm tnflltin procMMt. that AnpU rtek noM is wfejch ibt ^rherais of individual vetoes for Kt lung cancar excem to multiplied by &1 ooron tun ardan af majiltwda Bua (10*1 to appropriate far aattowttag tho OdOM to axm. The arithmetic neat of risk boa gastrointestinal caacar. Tka tha eieron vehiee of Kt (uari riak per f-y/ MttoMUo of risk Bom gastrointestinal eel team. aadOOST when the Ki's cancar an also given to Tabtoo 10 and I Boa adalag aad adlllag an excluded. It. The gsoasPlc mesa of the date to HiW Cancar* at aria* otha tbaa tba luag, mesotbeiiuax aad gastrointestinal tract whan tha eednatoe of Kt Boa stilting*. milling operadans an exduded. the have booa shown to bo alovatad to aooa asbeato* exposure stadia* inriudlng laryngeal. kidney, pbarynaeal tad buccal catrity caacar. To OSHA. it appear* that tba excess riak far 'other geometricaeon af the Kt's is00113.The K|`a hero e median of 0B091 with tha pfOGBSNS nd 9 of OWi whan the mlatof-adBint cancers' Is about tba aaoa as far lastrointasttoal caacar* OSHA rwognieea many uacartaiattoa to quantifying this riak. to da* af tba tacoflAlAtcnctei it fipdtafi ismsi different epidemiologic atodia* (! itudiea bao faoad axcaaa riak fr other caacar* while other stadias ha** not) Tba aitsa shewing turn risk has* also varied among atodia* Tbatafaro. OSHA baa act ado mnaanral MttoMtaa at risks far tbase other caosaa at this -tto* Tba data indicating lastrotataattaai cancar excsss** an imager aad man coaststant tbaa tba data suggesting axcaaa at tbaa otha cancer aria* OSHA doe* not ftai compelled to quantify dda riak at this time. Tba high quality and arrik supported estimates af excen riak af mortality from hog eanoar. mesothelioma aad aabastaais alone provide sufficient bean epoa which to justify this Eitimatm ofCaacarUortaiirj Considering the Industrial prncaaaae other than mining and stiffing. OSHA baltoroa OBI to be a reasonable astouata of Kc ft to tba geometric mean and mediae of tho Kt'r derived tram studios of asbestos manufacturing and fasutottgn application proeases, Thu geometric moon ban the advantage of minuting the influence of outlying vuIum end a Kt of OBI to approximately within one order of magnitude of all tha estimates of Kt- la sum. the Kt of OBI to a beet eedaute which coniaina . appropriate recognition of studios with higher and lower rouses of 1^, It should bu noted bowavor. that tbs uncertainties artmod this atimato of 1^ an such that an appropriate aotimato of Kt could Ua between MM aad 0B3. Tha asUmataa of Km givea to Tabto 13. ate derived bua ttudiee with four at tha flro highest Kt value* That !* there to some bias to examining tha value of Ka Independent of the Kt in the seas studies because it to likely that these K, A best estimate at 1^, urea estailsted would tend to be slightly higher then for each of the eleven epidemiologic those derived boa other studio* das to studies end on estimate of Ka was the demonstrated high power of thaw calculated Boa four of these studies studios to detect riak Ilia arithmetic (see Table S) (Ex. 94-393). For sack mean of the Ka'e to 4J9x UT*. aad tbe study, the best eettouta far K(. end Ku to geometric mean of tha K's to ttlxltn. indie*tod along with a rent* of To account far somo of this bias whan uncertainty. The ranges Hatad an these an the remit of estimatae at exposure tttimatiag Ka. It la uaafal toaxamin* tba redo of Km to Kt- For tha four studies far uncertainties (usually a factor of Ik which Km was calculated, the range of methodological uncart*tatin that led to the ratios of Ka to Kt is only two-faid alternate evaluation* of riak or <*\ptun (Boa 071x18** to tJSx UTT- Both the arithmetic end geometric means of these ratios are 1X10**. Thu* t x 10'* la aa appropriate choice aa the best estimate of Km/Ki. (Mag this estimate of the ratio Ka/Kt sad the preferred estimate of Kt (OBI), the profarred estimate of K* nr*would be 1x10** (K*mlXW* x t x W*k A range of 4x ur* to I x for Km weald appropriately represent meet exposure situation*. Then to no evidence to (hi* analysis that would suggest that e special lung esacer potency to ascribebie to a specific type of fiber. Some of the highest and lowest values for Kt art obtained Bua pure chrysolite exposure*(far exempt* Kt calculated from data of Demon! at aL to OOti using data from Fata at eL gfros u Kt of 0B079V Exposures involving a mixture of flbors. iaditdhig smosita and creddollt* also spaa a large nags of values for Kf Wide differencm tiro occur to the results of separate epidemiological shuHo* rf wwl """illw. Soma sdanttots have suggested that some aabeetoe process** auch aa asbeato* textile maaufactwiiim may pose a pester heaatd than other pipcnii^ Foe CMB^plie milling appear* a pose e Imror cardnog*nlc bassrd tbaa manufacturing procoqq. OSHA csopurud the potency (actor* far hog cancar (KJ among different epidemiology stndi** of manufacturing procaua** bucaua* tha patency factors are baaed on risk per sail doe* No consistent patten of differential hmg cancer risk (La. higher H's) by process emetgod- One study of asbestos textile workers found e vary high risk while another found a much lower risk, and the same was tru* for tha two studios of Mbaatcs production workers and th* two studio* of asbestos camaat workers. Tbsrafora. th* choice of a midpoint unit risk far all industrial process** (KiwOBl) is * rtssonsbis snd justi(tod choic* Tba bast atiauto* of Kt and K. wsra utillrod to wtimatt tho mortality (ram sxposuras to varying concentration* of asbestos far dUhrsnt lima period* beginaing at different age* The ceteutotiene ate eg* Intensity and duration specific. Table* M aad 11 show tba excess asbestos rotated mortality rata* Bom lung cancer, mesothelioma, and gastrointestinal cancw (gastrointestinal caaear ucm it assumed to be 10 percent of the lung caacar axons), fat Amo calculation* Equation 1 aad .Equation 3 war* used with values of i*. equal to OBI and K* equal to txiO-- snd tha 1977 U.S. male background lung cancar mortality rates. Because of ago-aptdfic incresaes in lung cancer rets* to older men since 1977. 51126 Federal Register V Vol. 4R. No. 213 / Friday. November 4. 1963 / Rules and Regulations fthmates based on more recent background rates would be higher. Calculations were dune for each 5-ytar sge interval. and then summed to give a total lifetime risk. Tbs calculations performed to give the results in Tables !0 and 11 assumed that the relative risk increased following ten years after onset of exposure and continued lo rise until ten years aftar cessation of exposure. efter which it remeined constant. Table 10 gives estiautes of risk for one year of exposure to asbestos at vinous concentrations for worker* beginning exposure at ages 20 30 SO 30 and 00. It should be noted that employees exposed at earlier ages shew higher risk of all cancers dee to the loag period of time daring which It wig be possible for disease to develop. One year of exposers lo asbestos at 2 f/cc itsrting at age 20 may result in a total excess cancer risk of MS par 1on,000 workers. Table 11 gives the predicted exosas lifetime risk of cancer for exposures of one year. 20 years, sad 42 years assuming first exposure at ant 22. Several comments should os made regarding the results la Tables 10 and 11. Thoegh excuse relative risk is Unaar in dose, the excess mortality rataa given in Tables 10 and 11 are net strictly Unaar in doe*. Therefore, for example, the nsk el 2 f/cc la net exactly 4 times thr nsk l 0.3 f/cc though there it e cluse approximation. It should also be noted that the risks for longer periods of exposures do not appear to be a straight-forward multiplication of the risks of shorter duration, la the longer exposures categorise where exposure will effect older werksn. some ediustewnts have been made for competing risks wkich are likely to affect the death rate hem long cancor. la addition, when looking at the total cancer risks, it must be reawmbersd that these include the risk of mesothelioma, which is related lo Haw In aa exponential feshioai As can be aaaa (ram Table It. the predicted risk from awsethelloma ie approximately eqOal to the hmg cancar nek for one year of expnears and. about one-half the risk value for hmg caacar in the 20-year exposure peep. The steam risk of mesothelioma after a lifetime exposure (42 years) lo asbestos is ppraxieieteJy one-third the lifetime excess lung cancer risk. These predictions comport with observations in several populations, where mortality from mesothelioma ia observed to comprise approximately SO percent of the excess mortality from lug canear.- Using the equations given earlier, and based on the calculations ia Table u. OSHA predicts a lifatima excess risk of total cancar far a lifatima axposura (42 yeursl lo 2 f/cc as 8.411 sxcass deaths per 100400 workers, or approximately M per 1400. Recognizing that a 20 year exposure to asbestos may be another approximation of actual worksr experience of interest, the model* predict aa excam caacar mortality of 4J92 death* per 100400 workers. Reduction in the PB. from t f/cc to 0-S f/cc reduces the risk from lifetime exposure from 04 pur 1400 to IT per 1400. Similarly, for a 20 year exposure, the risk is reduced from 44 per 1400. to it per 1400. representing a m reduction in risk. The lifetime risk from on* year of exposure fellow* a similar course. The risk reduces from 290 per 100400 at 2 f/ cc to 74 per 100400 at 02 f/cc A* discussed above this implies that the lifetima sxcass risk from s sixmonth exposure to asbestos would be approximately >92 par 100400 at 2 f/cc and 31 par 100400 al 02 f/cc lastly. Table 11 contains the risks for levels higher than 2 f/cc because OSHA believe* seme industrial area* (such as construction) may bo at thee* higher levaic This population of workers would consequently experience e inch greater induction in risk by exposures to 02 f/cc or lees, xus earn smm on Cll Ol CO CO Federfi Rc-.Hler / V0|. 4a. \0. ;u / Frulny. November 4. 1983 / Rule* end Regulation* TtOle 9 Estimates of tlw Slop* Paraaeters for Lung Cancer and Hesotneliana (**1, by Process 51127 Study MNUFACTURlhfi KflJuO* Asbestos Products * Henderson i Enter) me (1979) 0.0047 (0.0026 - 0.0066) . Asbestos Cenent Products del 11 et al. (1979) 0.0033 (0.0016 - 0.0086) finkeistein (1983) Testlle Products 0.067 (0.033 -0.13) 12 (4-30) Peto (1980) Oenent et a). (l982) 0.0076 (0.0009 - 0.023) .042 (0.023 0.21) 0.7 (Q.3-2J Friction Products berry 6 Neuftouse (1983) 0.0006 (0 - 0.008) Insulation Products Seidnan et al. (1979) INSULATION APPLICATION 0.068 (0.0049 - 0.14) 5.7 (3-11) iellkoff et al. (1979) HININ6-HILLIN8 0.020 (0.008 - 6.030) 1.5 (0.5 - 2.5) * LlddeVl et al. (1977) Nicno)son et al. (1979) 0.0006S (0.0002 - 0.0011) 0.0023 (0.001 - 0.007) Rubins et' al. (1979) 0.0051 (0 - 0.009) 1 Values In parentheses represent cue range of uncertainty around tlw estimates of and Kfg. These are computed on a study by study basis and calculations for each study are discussed in the test. KH/Liii6l 1.79 0.92 0.84 .75 ST 0006000 51128 Federal Keeler / VuL 48. No. 215 / Friday. Novroilivr 4. ivoj / Kuli-s and Rrjjtiluiionii Table 10 Estiaattd asbestos related cancer aortal it/ from a on* year exposure to various fiotr concentrations' Asbestos fiboc concentration (f/D 0.1 0.2 O.S 2.0 Cancer aortal It* /lOOvOOO exposed Mesothe- Lung lioaa Gastrointestinal1 Total Age at first exposure: 20 7.2 9.5 14.3 . 18.9 35.8 47.3 142.8 186.7 .7 1.4 J.6 14.3 16.2 34.6 86.7 345.8 Age at first exposure: 30 0.1 7.3 4.9 ay 0.2 14.5 9.8 i.4 0.5 36.3 24.4 3.6 2.0 144.9 97.4 14.5 12.9 25.7 64.3 256.6 *9 * first exposure: 40 0.1 7.1 2.1 .7 9.9 0.2 14.) 4.3 1.4 19.6 0.5 35.3 10.7 3.S 49.5 2.0 140.9 42.6 .. 14.) .197.6 I 00SC00.1 .s 0.1 " 0.2 0.5 2.0 - 0.1 0.2 0.5 2.0 6.1' 12.2 30.4 121.7 Age at first exposure: 50 0.7 .6 i.S \*2 3.7 3.0 14.7 12.2 7.4 14.9 37.0 146.6 4.0 8.0 19.9 79.6 Age at first exposure : 60 0.2 0.3 . 0.9 3.4 .4 .8 2.0 6.0 4.6 9.1 22.8 91.0 ` 1 estimated u 10k of lung cancer risk rather than calculated using dose-response inforaation. Federal Renter / Vul, 4*. No. 215 t Friday. November 4. 1983 / Rule* and Regulations Table II Estimated Asbestos Related Cancer Mortality per 100,000 by bumper of Years Exposed ana Exposure Level! 1 51129 Asbestos fiber concentration lf/D 0.1 0.2 0.5 2.0 4.0 f .0 10.0 _ 0.1 0.2 0.5 2.0 4.0 5.0 10.0 0.1 0.2 0.5 2.0 4.0 5.0 10.0 Cancer aortalIty /100.000 exposed ------------- MesothV ----------------- Lung Home Gastrointestinal2 Total 7.2 14.4 36.1 144 286 360 715 139 278 692 2713 5278 6509 12177 231 460 1143 4416 8441 10318 18515 1 year exposure 6.9 13.8 34.6 138 275 344 684 0.7 1.4 3.6 14.4 ' 28.8 36.0 71.5 20 year exposure 73 146 362 1408 2706 3317 6024 13.9 27.8 69.2 271.3 527.8 650.9 1217.7 45 years exposure 82 164 407 1S54 2924 3547 6141 23.1 46.0 114.3 441.6 844.1 .031.8 1851.5 ' 14.8 29.6 74.3 296.4 591.8 740.0 1470.5 225.9 451.8 1123.2 4392.3 8511.8 10476.9 13996.7 336.1 670.0 1664.3 6411.6 122C9.1 14896.8 26507.5 ST000G002 1 Assumes exposure begins at age 25. Risks are calculated using u.S. ale lung cancer background rates for 1977. 2 Estimated as 10X of lung cancer risk rather than calculated using dose*response information. 51130 Federal Rcyivfor / Vul. 4H. No. 215 / Friday. November 4, 1W*3 / Rule* and Regulations y Quantifying the Exerts Hisk Emm A>0csto*iS Many nudies ha\-e found thr noamaiignant lung disease. attn-siueix .among asbestos-exposed worker*. In fact, early occupational health itandarda governing asbestos expuaoro primarily tough! to reduce the incidence of asbestosis. Aabeetoaia la a type of pulmonary fibrosis diagnoaed on the batit of a history of expoaure to aabettoa: it it characterised by radiologic change* to the lung, breathlessness. unpaired lung function, and other clinical Naturae of flbroaing lung disease. Aabeetoaia can be manifested in a range of degrees of seventy and can result in disability and death. An early response by the lung to asbestos expoaure is formation of plaques, which are opaque patches visible on chest X-rays. The pretence of plaques might indicate increased risk of future development of asbestoaiv but this i* not certain. Although the disease significance of pleural piequca it not dear, the presence of the plaques is not mhimL Berry et ai. (18TE Ex. 04-30) dcGnas "possible aabeetoaia" as a lung condition based upon signs of tarty asbestosis. Ha classifies 'possible asbestosis' on the Boding of basal rules or crepitation, radiological changes of varying degree, a falling gas transfer factor, and restrictive msnges in lung volume or ventilatory capacity. The definition of eabestosia varies among different investigators. Berry et aL's definition of potaiblo asbestosis. for example, is not sufficient for the victim lo qualify lor British Disablement FcnefiL Asbestosis can progress to a disabling condition where active work la no longer possible. Although no tingle definition ot disability exists. venous govsmments have adopted definitions of asbestos disability to administer their worker s compensation laws. Flaknisitin explains tha system uaad by tha Ontario Workmen s Compensation Board: AsN'xtusis has been known to I'rogrrss ur worsen after cassation of exposure. pruUalily duo to imverstble iniury and/or the retention of asbestos fillers io the lung. In addition to lung function impairment, aabasloeia contributes to increased atbestoe- reluted mortality. Increased resistance created by the lung obattuetton can lead to heart falhm. Becauat of tha many possible definitions of asbestosis given by different groups, the quantification of a single risk associated with asbestosis la difficult, ft it dear that material impairment from asbestosis occurs prior to tha onset of its disabling stags. Quantitative studies exist primarily for tho disabling forms of tha disaaac (pacifically, twe separate studies provide information to develop a doseresponse relationship between asbastoe exposure and incidence of asbostoeis .(Ex. 84-20 and 84-44). Two definition* will bo helpful in interpreting tha data concerning asbestosis. Incidence is tha rata at which new rssee of asbestosis davelop in a given parted of item. It is a direct measure of the risk of developing the discs**. On the other hand, prevalence measures tha nuafoer of cases athra in a population at a given period of dm*. Numerically. It oqanla tho sum of all the incidence caaas in the pact minus all tha deaths that haee oceanad in peapte who bed developed the disease. Prevalence can be reflective of existing risk for asbestosis in a population: prevalence however, can be hid* hr other reasons, such as Increased survival Moreover, incidence establishes a daw sequence wheraaa prevalence looks at both cause and siTeci simultaneously. Tbs best tstimalts of risk of asbestosis have been calculated from incidence dais of two studies. Berry and Lswinsohn (Ex 84-254) and Finkelstein (Ex. *4-44). OS! (A has alto examined prevalence rates to support a quantitative assessment ef risk (or asbestos, and theas data will be discussed first Bury at ai (1*7*. Ex. *4-20) studied a pbupefOT man who worked at an asbestos textile factory for at least 10 yean. Dust measurements wen available and wan correlated to each job performed for each year under study. Hsalth effects wen correlated to emulative exposure. Table 12 show* the observed prevalence of crepitations, 'possible asbestosis'. and certified asbestos for data from Barry at aL. as lakes from tho fitted curve In Figure 4 of their paper. Possible asbestosis was diagnosed by tha factory medical officer if he thought that a own was developing signs or symptoms of ttrly asbestosis: SO* of the men diagnosed with possible asbestosis received certification within the 1J years following this diagnosis. Tha results in Table 12 represent a group of workers ampioyea afiar 1880. who had a relatively abort duraboo of follow, op (maximum interval from first exposure was 23 yean). A higher percentage of asbestosis would most likely have been obeervad if tha follow up petted in tha study had bean extended Tha observations of Barry et aL pwaantad in Table 13 am probably underestimates of risk. Fine tha risk shown in Table 13 doss not givo the probability of daraioping disease after exposure has ended, but rather, toporu the diaeate found at one point in time. Second, the data includes soma workers who may oat have beee followed long tnough for asbestosis tn appear. TAitl 12 mwalcki or cmyitatioiis. rosjisu asmstosu aw cwimo Aucsrau rat amxjkTiu t-crosutts to asustos mob Workers subiainine deien la the Compctuelten Board ore oxaminsd by dw Ad.ieon CoteauttooL whir* recommends whether or sot o Disability hankie he vur tod. Then ore no strict erttene (nr the aw ird ns of o Disability Pensica lor ilesaiou. but eomo of the (acton cranidered indvdc o kMury of 'aikituatr" rxcooan. o history ef dytpooo. thr jn-stm of crvpiloitaoe sc chib'keg rad.uen.piue uf* of pulmonary fWiraata aod sboocotoi pulatoaar.' fuocitaa rnolts (Ex. *t t. p. itn| KNtl M *1. 05791 Percent vita canonise 1 i \i IS Cimutative sieosurt. ftsar/ct rears Crept tst tent Pttttai* Asesstosts 17 44 41 4 111 ^00 IJi Csrtiftsa Asbestosis U 100 110 148 r STOOOGOG3 Federal RcylUct / Vul No. m / Srirtuy. Now mber 4. l>XU / R,,lci jnii R.-.-J.a.c:-* 51131 ThM data of Derry el al. drmunstrutr severs! featuras of the nature uf the aibestosis rink. The dale show a continuum of clinical response over the range of doses: dial la. time clinical obsenrstiona support the existence of a doee roipowae reiattonship. Second, iheee obaorvsWons aba rapport the evidence of * low. or possibly no. threshold fur aibestosis. sine* there is increased risk at cureillative exposures as low as 37 fiber/cc-years. Derry and Lewinsohn (1971. Ex. *4- _j4) have reported die incidence of asbestosb in this same esbeetue textile factory. These data are presented la Table IX A duse*<eponse relationship is apparent for the incidcnre data, but n u nut quite as consistent for the prevalence data. Table 13 Incidence of Possible Asbestos is b/ Cuaailattve' Exposure Berry and lemnsonn emulative Exposure (flbor/cc-yeart) 0-49 S0-99 100-149 ISO-199 200-249 300-349 X Incidence First employment Before I9SI m 3 2-6 3.9 6.2 4.6 After IrsO 0.4 1 2 * o0 9C00 1 S FlnkaUteia (IMS. Ex. b *4| looked at the davelopraeot of mmpensable (carti/lad) asbaetoab among 301 worhees at an eihaitna remaat factory la Ontario. A doaa rasponae relationship t*a davelopad using eetunatad eunmlative exposures based on plant dust measurements and using medical Information bom die Ontario Workman s Compensation Board. Tibia IS shows the inddanes of certified ashestoeis casaa as a function of cumulative exposure from the Fbikelstein shidy. _ TABLE 14 IHClOEhCE OF CERTIFIED AS6EST0SIS AS A fUKTlOh OF CUMULATIVE EXPOSURE FIMCELSTEIN (1982) Cumulative exposare flber-years/ce X Incidence 0-49 50-99 100-149 190-199 200-249 o.s 3.4 6.S 7.9 14.3 Finkebtela'a (1MX) obacnralimminay because at aetopay. there wee hbtnlngtr evidence of riBcsob aa wafl as aabortosit Is many mta. Ftahelslelp states that "we have, neverthaksa. chosen to caD their disease 'usbestosis' xa we belleee that b the pathnlogtr proem of meet significance. Mast of the parenchymal radiographic almarmeUtbe were small Irregular opacities and the mortality pattern among the men was consistent with the tiixie rfTrctx of asbestos.' On the other hand. Plnheltieia's stady may have uodentatad aabastosu risk by aiamlnlng only certified disability froci asbestoaia. which is an advancad stage of aabestoeb. OSHA's estimates of risk were derived bom a simple linear regression of tki os Mi^poiau of tho cumubllre axprsure data of Barry and Lewiasoha (Tabb 13) and Flnkrbteta (Table U|. A linear relationship was assumed, st bust to the point estimation of OJ fibers/oc for 43 yean (or 22J Tiber years/cc). This aaaumption b coasisiem with the fact that early stages of diseases an obamved at low exposures. A similar conclusion b drawn la the report of the British Advisory Committee on Asbesioe (Ex. M-X16. volume 2. p. 3gy "The present authors come down in favor of a dose rasponse relationship without a threshold for chrysotilr within ihe rungs experienced In industry.- 51132 Federal Renter / Vol. 48. No. 215 / Friday. November 4. 1983 / Rulca and Regulaliona MM li (ST IMATT1 OF UHTtK ASMSTOSIS IkCtOtaUS lioeturt levs), fissr/cc O.S t t t 10 Slope * 1 lociatecs Ftotalttela i.24 2.4t 4.17 12.4] 24.14 O.OIS 0.171 lerry: first aeoiuyos: afore IMI after li 0.45 O.M O.M O.M 1.7* I.M 4.44 I.JI (.11 b.tl 0.020.Ml 0.015 .1*4 Tiie result* of 4ach of the r|r*sfiaa analyses and predictions of incidence for several dose coneentrations are liven in Table li. At this time OSHA makes no aitespt io extrapolate the data using this modal below the OJ fiber/oc leva! or above 10 flber/cc levaL The estimatae from the S cobortt differ by an approximate factor of X This may be indicative of soma of the methodological issues raised earlier. It is possible that the estimates made from Berry and Lewinsohn's data may be underestimates. The maximum duration of follow up in that study was a years, with an average follow-up of io years. Observations hem Flnkelatain's data (his Table 1) demonstrate that only 41* (22/M cases) of total Incidence was axpertoncod in the Bret a yean sinae Drat exposure. That Is. SO* of the ssbestosm incidence woe not expraiaad until at West a years from Bret exposure. Thus, it is likely that the low incidence rates in the Bony and Lewinsohn study (and therefore. the low estimate predicttd by OSHA) are reflective of the short follow-up punod for this (roup of workers. OSHA believes that the heat estiiaatas of the incidence of ssbestesia are those derived from tho Flnkeisteia data. They indicate that among warkan exposed for a lifetime exposure to 2 f/cc of asbestos, approximately S* will develop atbestosia. this level to OJ f/cc would reduce Inridence to 124*. It should bo aotad that those risk Mdmatao rapssssni incidence of disabling asoesraria. First signs of sdvone puhnonary effects ars isportod to occur at lower levels. C. Othtr Qucntitatirw Riti .4xwus<neita Since 1*7* several scientists and scientific csmmittaaa have estimated risk sssoaetsd with ssbaslos exposure. (Exa. M>1,04-1 04-210.00-25*1 The risk assessments are In approximate agraemeot. They all use rpidcmioUqrcal studies ronductrd io ihs occupational environment lo generate quantitative estimates. Animal studies an used to only support sad justify methodological procedures and assumptions quelltativsly. For lung cancer, scientists gtnemily accept the linear modal relating increased asbestos exposure to risk and generally accept the leek of o threshold. As stated by the British Advisory Committee on Asbestos: Tor lung cancer, the available date in man. all of which are derived from industry, show on increase in risk with increasing dose of duet end we And no evidence within the range of dost levels studied fora threshold of dose below which there Is no evidence of risk" (Ex. 84-21* p. IS). In general. all tho risk assessments use cumulative exposure as tho measure of oxpoeura for all cancer risk estimates (cumulative exposure equaling intensity timas duration of exposure). Qvdfc tha uncertainties Inherent tn qeaatitativs risk msssmant. at weJ as tha inevitable variaUoae in flndiaga among tho many epidemiologic studies. OSHA believes that tha different quantitative risk estimates agree relatively well. The strialions that do exist con bo explained by tho assumptions mode or by sinpie methodological differences. Some variations may be doe to differences in the work eoviroomeai used in the eeeemtnenta. For example. Cramp's assessment given aa testimony to the Ontario Royal Commission so Asbestos m August Ifltl. contains quantitative estimates of risk far several studies. Including smohlng-tpeciflc risk estimates. Cramp does not rive best estimate of risk or an overall risk estimate. His tstimates of nak are based upon io esrunpitoo that worker exposure that weald result from standard set at a 2 flber/cc limit Is actually orach lower than 2 flbers/cc. That 's. his risk rstimata under a 10 fib 'nice standird assumes that average worker exp mu would bo only 10 flbcn/cc (p. 4P). He reduces this level by a factor of two to account for difforencoo between personal end static sampling (e. go). Thus. Cramp's estimates far a < flber/cc standard will be four times lower than those estimates arado by OSHA Car average worker exposures of 2 flber/cc Sock differences In assumptions should bo kept in mind when comparing risk assessments by different authors (Cramp's qetimsts st 2 f/cc would be compared to OSHA'a rstimata at OJ f/cc). OSHA has presented the risk as if tha working population ware exposed to an average concentration of 2.1. OJ sod 0.1 fibers/ cc redacting OSHA's belief that a standard of 2 f/cc does not preclude worker exposure at that level; in fact exposures may ovea exceed 2 flbers/cc for short periods end still produce so 0hour TWA below 2 f/ce. Tho report of tho British Advisory Committee on Aabestoe contains one of tho flrat quantitative risk assessments performed for asbestos. This was updated in 1002 by Acheson and Gardner (Ex. 04-242). The report describes risks for lung cancer, mesothelioma, other asbestos related cancers end esbestoeis end it centime s rather thorough description of ths health bexerds associated with aabestoe exposure. The British report's risk tstimates for lung csaccr do not differ in a ma)or wsy from OSHA's satimsiss. For example, with regard to exposure to chryaotlio. tho Achaean and Gardner update states that "We concluded that, far example, an excess mortality from aabaatoe-related disease of 2 percent might be associated with any point m e range of from S fibers 'ml to *4 flbers/ml and that bearing in the mind the very considerable uncertainties a figure towards the lower end of tha errs) [0.4 f/od] bright represent in appropriate compromise." (Ex. M-243. p. 141 As a compartson from Table 11. OSHA's best estimate of risk la that an exposure to OJ flbers/cc (mi) would result tn e 12 percent increase in deeihs from lung . cancer (or 1143 excess deaths per 100000). VI Techsdcsl mi Tnoairarir Feasibility Baaed on an evaluation of evidence contained In the record. OSHA finds that the provisions required by ths ETC era technically and economically feasible. OSHA hoe examined the various Industries tad work operations impacted by the standard and their ability to comply with the provisions of tho ETC. Because the ETS requires prompt reduction of risk. OSHA c n n q f. n0 J S Federal Register / Vol. 4a. No. 21S / Friday. November 4. 1083 / Rule* and Rf$uUtiont 51133 ( a'tetted the industry's ability to ciinrenmtiOM. Furthermore, for bo understated. Furthermore. OSi IA Nm' implrmmt the requited cnniruls purposes of worst-case analysts. OSHA not included In the cost analysis s immediately. assumed that none of these industries consideration far lost worker The ET5 allow* considerable has any respirator program except far productivity doe to wearing respire too. flexibility in tchirring the PR. As a the shipbuilding and construction Costs may be understated by whatever result three option* are available to irgmsntr 08HA makes Air assumption omaont productivity fa reduced. Other lower the asbestos fiber eonoeeMdeas beesuse OSHA aetimetes that moat ntidpetod respiratorprogram drownt* to which workers ate exposed! (1) Engineering controls such * sutomntlc beg opening device*, tpecialiasd vacuum sqaipmont and Increased ventilation: (2) work practices. sock an w*t treatment of tho asbestos material and increased dean-up of the work place, sad 01 use of approved respirators. Due to the smetgsncy nature of this action which requires Immediate response to reduce worker expoeutu. OSHA stsumes that respiretor* wffl be. the initial method used to comply with the ETS A full discussion of die workers In Industries other duo topmuoa^ m wwiwcBw nv exposed In sight hour time-wrtthird averegos leas than 2 t/ee. end the OSHA standard leaned in Wl only mquine a reapirutor program whan engineering controls and usd practices ooanot bring exposures to 2 f/cc. Toths extern that soato firms do have an existing respirator program, the coats are ovcreetiiaaied. A. TtdutieolFtotlbiOtf The toBoertog table presents the required to detonator costs for the ETS to Bstod hdow. These dements are derived ftom tha axisttog prot fsions___ found to tha Asbestos Standard. 2P CFR maiOOt and tha standards far respiretors. 21 CPE 10KMM. AO of the required respirators and fitters are readily available end con be purchased through local distributors. Since the program relies mostly on dtopooaUo respirators. OSHA considers that there will be no supply constraints. As the worst-case (or high) estimate. technological and economic feasibility of tha alternative method* broach industry and for tha various PEL* under assumptions OSHA made rstardbig the reepifotor prograto alaatanto teqelfed by each industry to obtain a PEL of OJ f/cc. OSHA sesames that approximately 10000 workers will wear respirators because of the ETS who did not considersban far revising tha permanent The types of respirators Deeded far ssch previously wear respirator*. OSHA has standard wR accompany tha propooel industry sector were determined using concluded that tho aso of respiretars which will be published aaperaieqr. the respiretor selection table ia the ETS will bo sfTsctivs fa providing improved OSHA boliaves that consistent with with reference to tha estimated current worker protection during {he psnod of the estimates of current exposure levels. exposure conditions. OSHA assumed tha ETS. to addition to aoeooragtog tnginssnng controls are currently in that tha least costly approved respirator generally more widespread use of piece end work practices, in operation * would bo selected. For example. whato re*pinlory protective measures, tha ETS which, if applied consQsattouoiy. would induatriaa havs axposuras lass than ton wtU stimulate a heightened immediately result in coneoanloon at Umas the PEL. OSHA utfdpaud that understanding of the health hesards least ss law ss 02 In many industries dlspeaahla raapirauss would be bom asbestos exposure and will result tSs.tMttlx.H4ttb.M4ulfa purchased, bscauoo of their lower short- to more effective use programs end II Mil. For purposss of rusering the farm coats. Whan exposures exceeded strategies. Issue* Involving tha tarhnolngirsl and ocomtudu feasibility, ten times the PEL OSHA essuomd that appropriateness of respirator use at a however. OSHA inumed a worst-eaae somajlanta umald sifaer use sir Uae long torn sohitioo to controlling scenario ia which each taduatry segment raefKretora. or faB facepiece raspinterw asbestos exposures are raised m the would have to Implement a respirator depending upon tha operation. To tha ecttan 0(b) rulemaking proceeding (tee program to order to achieve immediate extant that Ifarna choose a higher cost Ex. 11 Till It lid. It n'. m iig)_ reduction la w rkar exposure levels respitetat to inaeaaa the protection below tha estimated current factor or durability, respirator coats may 90090001S j ( k H l 51134 Federal Ryler / Vol. 40. \'u. .ilS / Friday. NiHcmltcr 4. UMS3 / Rul<;* and Rcgul.iiinni TABLE 16 Anticipated Respirator Program Elements Required to heet PEL Industry Segment Anticipated Type of Respirators Used to Heet ttie PEL Otner Program Elements Primary Manufacturing A/c Pipe * Sheet Friction Materials 1 dlsposeble/workday/workcr 2 air-line/plant (for High concentration situations;4 Full admin, costs^ Fit Test* Training0 Asbestos Paper Sestets I disposed Ie/worker/day SOS admin, costs for portions exposeu at 0.7S Fit Test Training Floor T1 le (Nothing for PEL of O.S) Paints.. Coatings and Sealants i oisposable/worker/day for 75k of workers 75k admin, costs Fit Test Training Textiles wet Process 1 disposed le/worker/Cay Full admin, costs Fit Test Training Ory Process 1 disposable/worker/day Full aamin.'costs ( Fit Test Training Secondary Fabricators Cement Sheets. Paper Products, Packing and Gaskets 1 disposable/worker/day * 2 air-1ine/plant for high concentration situations It admin, costs Fit Test Training Textiles 1 disposable/worker/day Automotive Aftermarket 1 disposable/worker/day Heouitdmg ana nerecing I air-line/plant It admin, costs Fit Test Training It admin, costs Fit Test Training u ------- CS. Federal RrutilVf I Vul. it. No. 215 / Friday. Nmcmlirr 4. WM / Rule* *nd Regulations Respirator Program Requirements '(Coot.) 51135 industry Segment Anticipated Type of Respirators Used to Meet the PEL Other Program Clements Brake Repair Gasoline Stations ShipbuiIdino/Ropair Shipbuilding Ship Repair Nothing Nothing Nothing I dtsposable/vorfcer/day for 20* of totai Morkforce 20S of admin, costs Pit Test Training Construction Installation VC Pipe A/C Sheet I disposahle/orfcer/day 10S admin, costs Pit Test Training Roofing Pelts DemoIition/Renovatloo Nothing 1 HEPA full face for 2SS of the uorkforce Repair 4 Maintenance Nothing 25* admin, costs Fit Test Training ' ST0 006 008 *QSHA assumes that certain job* such as cleaning of vacuum equipment will produce exposure levels greater than 10 times the PEL. Consequently, OSHA assumes 2 air line respirators will be required per'plant except for small operations uhich lll require only one air-line respirator per plant. '`Administrative costs represent the salary of one full time professional at (30,000 per annum and one full time clerk at (IS.OOQ per annum. OSHA ties adjusted administrative costs to represent expected reasonable time spent administering a respirator program in each industry, la the secondary fabrication and automotive aftermarket sectors, forexample, OSHA anticipates that supervisors *111 spend IS minutes a day distributing and nonito. ing the use of disposaoie respirators. These sectors have far less of a management burden than large firms, and thus, administrative costs are calculated at 1 percent of the full administrative amount. OSHA believes that administrative costs have been overstated in eost segments in order to present a worst case scenario. c0SHA asnines that every employee mist be fit tested for respirator use at a cost of (21 per employee. 0ShA has allowed 3 hours for respirator' and asbestos training. OSHA considers that this is very liberal, especially in industry segments characterized by small plants and by the use of disposable respirators. Costs for this element are therefore overstates to present the uorst-case scenario. SUM Federal Raqhtof / Vol. 4*. No. 21$ / Friday. November 4. 1963 / Rulce and Rcg-jlutions CSHA al*o examined the feasibility of analytical methods for measuring asbestos sir concentrations at the 03 f/ cc limit established by the ETS. OSItA'e iittiim standard requires that all inesaursmewa of airbonm concentretictw of asbestos fibers be made by the membrane Alter method et 400-4M x (mafsiAcatlea) (4 mlUlaeter objective) with phase contrast Illumination (If CFX tnatOOI(s)). After reviewing the relevant evidence made available stnee the 1973 proposal OSHA finds that phase contrast microscopy is a feasible and effective method for measuring airborne asbestos libers is determine compliance with the permissible exposure levels set by the Emergency Temporary Standard. The most Important issue raised by comments to tha 1973 aotice is whether phase contrast microscopy soalysis is capable of reliably measuring airborne concentrations of OS Abers/ce and loss. OSHA acknowledges that asbestoe airborne steeaurement procedures using phase contrast microscopy, as with any industrial bygiant analytical procedure, inherently containe several error sources. These anon have been tatiaticsUy evaluated by Leidel et aL (Ex. 14-421. and. in 1370 by the Air Monitoring Committae of too Aabeatoa Information Aaeocistion/North America, referred to herein aa A1A {Ex. MB) both using round-robin sample exchange data. Outfield also examined this question IEx 84-419). In the Leidel et aL' sad tbo AIA evaluations. the oner, measured as a imfflriewt of vmrietien (CV). was found to be related to the number of perildee counted from the fiber. For 100 fibers counted leidel. at aL found a CV of 0.12. wbersea the AIA report found e CV of 0331 or errors Hssocuted with iatorieboraioeyintrsfiiter variability. Basoc upon those studies. taken et their face value, it appears that dm phase contrast microscope analysis fa capable of rtsionebir rshsbio measurements at U fiborslcc. As stated in the AIA report (Ex 8-000 p. AB-2L "The calculated results Indiceta that the w*w 4 tone CV he sis exatmeee asm So W* saaut* wtaeUi MS-* 1W *nWw aenMer i well aSacMi' n Sitffa 4 h OUs MJ> way U man f * r 0!%mnee er lamrrnumes Iran me iamwm w Sw seal and was not tia a maiidaWaMaWMV.Aaar.anMe .Iruy I runeOas me wipaiMeaiarid swatn sa n maan w riaaaiun Cut. warm a. .* nr S*l arurrM*. tarn aa Ur.im te 4.M Mr Ht confidence limit* on a measured *hoar TWA can be relatively constant with a wide, but usable, range down to ceacentratteas approaching OJ fibers/cc [less than) SU.* The AIA report shows s hightr smr then dogs the Lsidel at aL report. One possible reason for this difference may be that the AIA report ssssssed the variability in measurements as they era being made today by the many laboratories who era making the measurements. Far example, only V of the 40 Isboratorias participated in tbs PAT program and no counting guidelines were given, whereas, the Laidd et aL report included only e small number of laboratories operated by Johns Mensville Company, that probably uaod very similar procedures and conducted wi<ftp tntnte|i In lata 1002. Chatflsld prepared s raport ntitled "Mmursment of Asbestoe Flbrs Concentrations in Workpiece Atmospheres- for the Royal Commission on Motion of Health and Safety Arising from the Use of Asbestoe in Ontario (Ex. 34-413). Outfield analysed bun-end inler-Uboretory variability and strived at condusiooa somewhat almilar to these of AIA and LeideL Chatfield also recommended methods by which the accuracy end predsiaa if phase entrust microscopic analytical techniques oouid be liuprVari filguifiremly he nntsd *1a view of tbs number sad frequency of meosuremasts required. there U cunentiy no fully developed aUarnative owthod |to phase contrast microscopy) which could bo immediately implsmentsd.* OSHA notes tkelthe autharitlse died above baaieve that It may be poaeible to redan phase contrast microscopy errors If improved end standardised procedures are followed, perhtpa by adding requirements to tbs standard. It don not appear. however, that Improetaunts of this nature can be' quickly mode in the immediate format of this CTS. Therefore, based on the evtoeon before it tt the Urns of unsure of this smetgsncy standard. OSHAbeUevas that it is gsturally sot poasihte to measure asbestos concentrations below ILS 1/cc reliably end rcprodudbly using phase contrast microscopy under cutrsnl tabaruiery practices. OSHA finds that the phase contrast microscopy method nn be feasibly used to measure asbestra sir concentrations down to tLS (let. 8. Economic Ftottbility The industry nets based on the program elements described in Tsbls 13 era presented in Table 17. For the ETS. the coats of asbestos traimog are Included with respirator training. Costa for watnfcm signs are aot included, since, far no purposes of the ETS. then signs could be bend-nude at very lew coots. OSHA did not analyte costs associated with the alternate benefits scenario (See Table 4) since that ecaturie was constructed to show a lower range of benefits bn don net loprasent an estimate of current industry pritaties. Tbo nets ora evetststsd to the extent Out seme firms already have a currant reepiretor program and to the extent that careful epplintion of existing engineering contrail end work practice* would reduce concentraoaas to the PEL In some firms end thereby auke respirator use unnecessary. Furthermore, the nett assume that dust masks and filters will have to be replacad every 3-hoor day. Soma of this eoet (Le. the disposable respirators, filters sad administrative overhead) con be in feet spread oxer the period during which the ETS le in afleet Finally, the enu assigned to the ShipbuUdina/Repsu and ConstructionDemolition/Renovation tegmenta represent east which reflect increased i with current obligations (e.g I reepiretor use to meet the H standard n a result of the ETS training requirements) and sre -ot directly attributable tc the ETS. Wees. OSHA enttoptMe diet the ETS will par many tmptwym who prwmaiy were aorta mmpUsnne to esoend the sereesary raeoweee m order w came mto ounpiM-ica wUhtbaCTS. The total coot la ettimeled *i 88.333.402 far mouths. That translates Into aa average eoet per employee of 3704. Average 4 month costs per worker presented on an industry basis in Table 1? range hem 831 ic the automotive aftermarket segment to 3973 in the cunatractloa segment. These eotts are note large portion of industry ttuptranu aa presented in Table II. Moreover. Bnu in those indeatriea will be able to pass the coats forwent bscauso asbestos substitutes in most industries are not immediately available For all these raisons. OSHA finds that the ETS is economically feasible. ' s T 0 0 ; 5 C0 3 Fa^aial Ragislar / Vol. 40. No. 215 / Friday. November 4. 1M3 / Rule* end Regulation* Tatle i; Utiettw Cette ef flet*ireter Sreprw far (TS atte Hi of O.t letettry SeuHOt Teul Cesu ($; tee. eaerege rur eoatet Cett/eeploses fruey ewaftcturiae e.40t.M0 .IU.i * ttl l*coeery Fwrtcetert Aeteettiae Afteremet U.M7.U4 l,U0.l*7 I.U27.M4 Me Ui Shtytetletef/reteieCeestrvctiw Teul - tu.ue 3LMJ* M.SU.4U st.sa ie.tM.ije M.ses.tot SU Hi ;oe sur S T O O U H U IU Title It CIS Coephwci Com Coeperee to Stitt ty lneattry iipwt IAOaitry Vipet Cost/Stlet Srleery hwefecterief A/C Site t Sheet Srictle etterlilt Aeeeetw Steer Siieu, Gettings we Setlwts (utitt, SetIt we Stcstegt Teat lies * Sicweiry Fttrlutere Ceeeet Sheets Steer Sreeacu Sect left we Sweu Teitilet Aateeociae Afteretrtet total letaf we tefaclef Stlpteileiag/leetir CoMtreetlw .00) .001 .000 .001 .005 .001 .014 .011, .01) .Oil ..001104 . .0004 .0001 .0004 : Selet ettaes ere Ter 1177 we l7t. eeleet Ter Srtetry Nwefacteneg we Socooetry Fttricetert -ere uteo free 04-00); velvet for tee Aeteeettae AFterwrtet aere twee free U.S. >--tttrtel Petloot. IW1; M vtlaet for 9tetUi*i/*Mtr iM uettrwctiw aere utBnPree tee I1C/M Stitlttictl tettrect. Tee telet fer Ceetractlee att tejettee ty lutstrtctiaf tee eie fer Mtyeaey t Streets we lettowttil we teetm tee elae for Oeeolttlee/eract'at. ** 5H38 Federal Rcytie* / VoL 48. No. 213 / Friday. Novc.t.Iht 4. 19M / Rules end Regulations Vfl. CnvironmcnUl ImptcL RequireaeaU of Executive Order I2S8L and (be Regulatory FlarihiMly Ad The National Environmental Policy Act (NEPAI of teas (UXC 4331 et raq.). u implemented by the guidelines (40 CFR Port 1300) of the Cooed! on Environmental Quality (CEQL requires that federal agendas aeoaoe their reyilatary actions to determine if there is a potential for a significant impact oe the quality of the human environment and. if necessary, la prepare an environmental impact statement. In accordance with these requirements and DOL NEPA regulations (30 CFR Part tt |Subpart B. 11.10 (a) (4||) OSHA had determined that bacauae of the emergency nature of this standard, no oevironmontal impact (element will be parparad for the ETS. The courta have held that NEPA does not require advance preparation of oe environmental impact statement for en OSHA ETS \Dry Color Manufacturing \nocattoa v. US Oapatvnant atLabor toe FM ee. tar (M Or. ten)), osha will assess, however. the anvironasantal affacta of tho prepcaad parmanant regulation of asbestos. Tbs results of this study will bo available for review and comment prior to the hearings on tbs proposed permanent standard and will be an appropriate leave for discussion tt the public hearing. In the interim. OSHA welcomes any mmmania on any environmental effects that might occur as a result of promulgation of a rule on asbetoa. Pursuant to the authority of Section etaKH of Executive 'Vdar 123*1 OSHA has net prepared Regulatory Impact Analysis of this ETS. Preparation of uch ar. analysts was not practicebis for OSHA to perform in time to issue this UTS to respond to tho grave dangers faced by asbestos exposed workers. OSHA. however, is completing a Preliminary Regulatory Impact Aaelyrie of the proposal to revise die permanent standard which will bo mode public at the time the prepoeel io peMiahad. The Regulatory Flexibility Am requires an agency to prepare a Regulatory Flexibility Analysis oaty far those rules far which a noties uf proposed rulemaking la published. OSHA's iaauanca of art ETS therefore is not ooverad by the Regulatory Flexibility Aci bereue* the OSHA Act pros ides that ETS's be farmed without regard to ncttca. peblic commoei end other requirements in the Administrative Procedure Ad. The proposal to revise the permanent asbestos standard, however ia eublmd to the requtrmnenta uf tho Regulatory , Flexibility Ad and OSHA will evaluate tho proposal to ascertain whether employers must be abla to comply with analysis under the Regulatory Flexibility the standard in a ebon period of time. Ad ia required. OSHA has sot o level which is likely to Via Summary and Explanation of tho bo achieved immediately, using ETS equipment and control techniques that e currently available. Tho requiremenu of this emergency Second. OSHA believes, baaed on the ntiporoty standard or* sot out la s new paragraph. | tttaion(k). They art data generated by OSHA's contractor. Research Triangle Institute, that some limited to additional provisions to tho workplaces, especially ia the existing asbestos standard which OSHA manufacturing sector, may bo dost to cofttidm mifliiil u)4 ftnibli io achieving o Oil f/cc level through tho protact amployaaa from the grave more rigorous use of engineering danger reselling from ssbostoa exposure controls, work practices and until OSHA cen promulgate more housekeeping methods which are oew in romprahaaatva revisions ia accordance place. OSHA encourages employera to with taction (fb) of the Act Tho me)or continue their efforts to implament these changes in tho standard made by the methods ia order to assure that for the ETS era: (1) The new permissible long tank tho most comprehensive and txpoeaie level: (2) methods of compliance permitted to achieve the new level: and (3) a requirement far the MtablishaMot of training programs within 39 days. The following section discusses dm motor provisions of the ETS. tho necessity for including these peovtaianrta dm ETS and tome additional provisions to trigger certain requirements at tbs reduced permissible level of 03 f/oe. effective program of protection from sheatoe exposer* will bo provided. Third. OSHA believes that reliability of lbs currently required asbestos measurement methods to measure asbestos exposures loss than 0J f/ec should be open (or dlsmeshm during a rulemaking hearing, rather then imposed through an ETS. OSHA boo therefore oot adopted the OJ f/cc level petitioned by 1. Paragraph (kjflj Scopo. As part of the ETS. OSHA la adding a paragraph the unions but instead ia considering adding provisions to the asbestos on the scope qf the standard. The paragraph is intended in make dear that standard that may improve the reliability of both sampling end anelysie the emergency standard applies in all workplaces where employees asay be in the 3(b) rulemaking for the permanent standard and thus allow lower levels to exposed to asbestos In all Industries covered by the current asbestos bo reliably omaound. 1 Paragraph fkj(3) Mothad* of standard ** genarnl industry. aomptianca. The ETS adds a new coMtmcttoa aad amttiflM. paragraph (kR3). which permits 1. Paragraph (kX2J PtrauotibJa level \ tmpioyere to reduce tho permissible ofexposure As pert of the ETS. OSHA a exposure limit from the current 2 f/cc is adding paragraph (kX2) which seta a 1 ^imil to the <L3 f/oc limit by any feasible now PEL effective Imasedlately. of 04II combination of engineering controls, oe on on hour time weighted average work prectioaa and respiratory basis. This reduced tavei may be J protection. The currant requirement in echlesud by any feasible combination or paragraphs (cHl) and (e)(2) to first engineering controls, work practical and uttbaa engineering controls and work respiratory protecttoe in order to allow prectioaa toreduce exposure levels to employers to institute iffsctive 10 f/cc remains unaffected by this ETS. measure* to reduce employee exposures Flexibility in choosing compliance immediately. . strategies for the period of so ETS has OSHA chose ti f/cc ea the \ bean incorporated in moat other tibia exposure level primarily \ previously Issued emergency standard*. i it balievaa that reducing The policy reflects OSHA's i axposuroo to OJ f/cc in all detenumeHon to craft emergency t urta greatly reduce tho risk of standards that ora truly responsive to developing asbestos i romusney conditions and which afford primarily htq < imasodtotaiy available protection to affected workers. discussion an "grave danger' end 4. Paragraph fkXI) Baptoyoo Itenefits". the numberad lives OSHA information anti training. The ETS adds believna may be saved through an a paragraph in tha asbestos standard , immediate redaction of exposure to 03 requiring the snplo) ar to provide a ( f/cC is !-> training program within 10 days of OSHA also beUaves that the OS f/ce level is appropriate for rrverol other puhttcatieo of tho errrrgeney standard for ail amplovsee whose exposures art V reasons. First, bacauae an emergency reasonably expected to oxcood tha PEL i standard must bo feasible, snd of OJ f/cc without regard to tha use of I I 0 9 0 0 0 S .i j4xv*irvrwxr,|,<' Federal Renata* / Veil. 41k No. 215 / Frida)'. November 4. 1HM3 / Rule* and Regulation* 51139 respireIon. and to assure that all sudi muliiptrs of the reduced PH. of OtS f/cc. Authority and flyiatura ctnpioyees pertidpeln in ihe program und are informed of ipeeffied categoric* id information. OSHA conaldere tMa provision to bo ~n*caa*anr~ within the meaning at soctiaa g(c) of the Ad to reduce the grave danger faced by eabeetoa eapoead employees. 7W rather than multiples of tbo previous 2 U cc permiasibl* limit For example, .(proved air purifying respirators may be used only where asbestos oonceatrationrare not expected to \ exceed I t/ce (10 a the PRJ. Before the ' ETS. baceaae the PEL was 2 f/cc such / This document was prepared under the direction of Thom* C. Auchtar. Assistant Secretary of Lobor for Occupdtionai gaiety end Health. U-S. Dspsrtiaaot *flabor. W Oonstitulion Avsaoa. NW. Wsihlrtstim. PC 121ft PbrsoHtt tg Socttamfbhifc). I|cl sod abeenoe at a training program requirement fat the asbestos ttandard baa been pointed out a* one of the u-rtoua dcAdend** at the current respirator* could bo used where asbestos concentrations woald not have exceeded 20 f/cc (10 a the PEL of 2 f/ceL Similarly, powered air purifying g) of tbo Act 2* OR 1910.1001 la emended by adding a now paragraph (hi as set forth below. standard. OSHA believe* that respirator* may be used where asbestos (Ssca. *(H tie). i(c| sad sis). Pub. L tt- participation in an adequate training program i* taaantial for the protection of impkiytti btctnii not! promUtt provisions enlist tbo employee a* an active partldpaat For example many \ concentrations do aot exceed 100 times the PR. which at the new level of(Uf/ oc is SO f/cc. Previously, employers could have used such respirators at concentrations up to SB f/oc. _ D ' st Siat. tmism. use. tson a UXC ass. sit Sen mp. AO Lti-st.nsiai.se (so U.&C. 22* OR Part lttt; Secretary o< liber's Ordsr Na Ml (a F* OTW Sgnad *t WasMagtsa. OC. this 2nd duv of mpioyses handling asbestos depend on \ lHaBksJy that the main tanpact of tha effective worhprectioea. Withe* trainingin applying these worh ! reduced PR on respirator choice will ba I in operations and Industries when >0.1 ii Am. Asusttar Sseesaryoflobar. practicoo. taplojFaa protection would be ' sxposura levels an between 2 f/cc and inadequate. Wham the emplqyoe plays a 20 f/cc. Formerly, rmplsya-- exposed in mete passive role la his protection such j this range could use half-mash air sa whim* engineering controls are railed ' purifying raapMtora: now they must ba PART 1S10--(AMCNOCDI CO Section 1*10.1001 of Part WOofTUkj a of tha Code of Federal Regulation^!*, on. Mining is alee essential hscaasa protected by a powend air purifying hereby amandsd by adding a new the employee mast know tha sourcaa of raspMlor or a hill facepiece respirator, paragraph (k) reading as faDow* WQffcpiMS ClblllOl OOBtftflttfMtiML Attd the health haxardo of asbestos exposure, ia ardar la sissss Us own sxposura or tboy may aoo a supplied air respirator. 1 Paragraph fkjft). Wanting rtjgn* |i*mm imtmsn . -- * *1 * o, ^ situstion and to haip mcogniso whan inginaoring controls are not operating properly. Certainly shot hooookeopiog during the 75 The ETS raqaMa that logibie signs wanting of the naaltb hasmds of asbestos bo displayed at effoctivotSwimbor'Z'Sl--<1) Scoao. This orngney tempiw aty standard ia plays an important rain in oonueL instruction about bouaokaupiag methods, for exempts, frequent vacuuming. is aaaaatteL Perhaps moat iatportanly. where amployaa prataction depanda upon respirator use. OSI LAs experience shows that Mining \ ampioyooa in tha use. fitting and \ limitations of raapMtora ia critical to I the sflactivanasa of respirator 1 locattone where airborne conceaMtiooa of asbaotoo Oban exceed the reduced txpoeurt Limit of 0J f/cc. No specific legend is required rip** tat newly posted during tha EI5 OSHA wtaheeto mahb as practicable u poeelble the rapid pouting of sipm. eepadally in workpieces where than baa been previous aon-compUacos and in areas when asbaatee concerttr*Hons wars issued poraaanf a section Sfc) of (ho Act and applies is ail workplaces whora employees may be expseed to asbestos ia ail iadaetitea covered by tha Act. indeedng. general indeetty. construction sad maritime. Except to ths extent modified by this emergency temporary standard all provisions of 11*10.1001 remain ia effect * (2) Pttmmnihin Isvu/s oftxpotu protection. Accordingly this raquiramam foneeriy below the 2J0 f/ec PEL. applies where airborne concentrations The B-hoar time weighted average airborne coocenMtloa of asbestos are reasonably sxpactad to ncaad OS f/ fiber* to which any employee may ba j cc. ran if employees aaa raapMtora to rsduca breathing ___ lnlsTislad persons ara invited to tuboul writtan data, viewa and txpoaad (bail not exceed ons-half (o Rbar. longer than S micrometers, par A and thereby comply with tha IT1 arpumaata with rvspact to the revisions cable centimeter of sir. as determine At sot forth la to ihe asbestos standard made by tha by tha method prescribed ia paragraph .-mpioyvr mus ETS. These comments must ba (e| of Ibis notion the health effi postmarked on or before |anoary X1904 (1) Mnthodn ofeompiianet with tho the raialtonahig sad seat to tha Docket Officer. Docket rarerjancy isntporary ttandard. smohingtai No. W-8MC Occupational Safety a Notwithstanding any other requirements operations -- \ Health AdmhtisMHoo. US Department of tide section, compliance with tha protective 1 of Labor. SO Constitution Avenue. NW. reduced ixpoanra Barit of OS f/cc shall steps to /Room 4 ITil. Washington. DX. 20210. be achieved by any feasible , proper nan. fitting The data, views and argument* that combinettoa of engineering controls, limitations of respirator*, and the arr subouttsd wiH be mdsbb for work praetiBne. and personal protectivk. cuntanta of all the provisions of the public inspection and copying at the Asbestos Standard at 1*10.1001. above sddresa. All Mady written (4| Smpkfm information and 1 Paragraph Panpiratar* submissions will bo mod* a part of tbo nofairy--<0 Aa soon as possible, bui /refection during tha STS. The ETS record of tha i not latw than fitirty (30| days from the adds a new paragraph IhRSI which\ includes a table which ties respiratoA List af Subjects In 2* CFR Fart 1*1* effective dots of this emergency tempomiy standard, the employer shall *!-'-lection to the OS f/cc FR. I'ndaf t! KfS. the cancontratum cot-nib f*u Occupational safety and health. institute Muting program fnr *11 Aabuetoa. Health. Emergency tompurary impIcyies exposed to airborne various kinds of rrspMkm *rr standard. Cancer. uunuer.Mtioaa of asbestos in excess of SIN# Federal Resistor / Vol. 48. No. 215 / Friday. November 4. lOM/Rules and Regulations 04 f/ct without regard to the use of \ respirator* and she# assure their \ portldpotlon in the iwyia daring ihd effective period of this weimp J temporary standard. (U) The employer she# anon thet each such employee Is informed of the toBewiap [AJTbe health offsets aaaodatod with ssbestos wnoaeroc (#1 The rriatian^lp betweso aahaatoa and smoking io producing long mook (Q The nature of eperatieoa which could result ia expocuru to acbeotoe cad monnijf puHtftht ittpi io otatata typotufo tnchktoifr -- tppHcobU. Afiootrtaf coatrote. woni praotfOM* mplfliOfli IM jvotNlivi doffaiog CP) Too purpose. proper see. Biting instnjctkms and UaOlotkMO of respirators permitted by the standard (E) A rsriser of a# the proriaiono coatsload In 1*10.1001. (5) Rmniratorypromotion during dm ETS. Notwithstanding any other loquiromont of this section. whore \ rsspintors are aood to achieve the \ permiasibio axpoeere 11ait of 04 f/cc / they shall bo aelocaad ocoordii^ to Tablet. (0) Warning tipm during dm MTS. Io addition to the requirements of paragraph (jHl) of this section, legible signs warning of the health hasnrds of asbestos shell be provided and displayed at cedi location where airborne concentrations of Jibestoe fiber* owy exceed OJ f/oc. TA4U I Inspiratory Frotaction For Atroome Concentrations of Assestea , Airseme Csncontrsttan Of Asoostos iTMAI st to OSCOSS of I f/cc (10 I PtL> at in eacess of M f/cc v'oo i raj treater Wen U f/cc Aeouiroo Aosairatar1 AoussOlO or single use sir purifying respirator fell facopteca air purifying respirator, or a pmeraO air purifying res* pirater A typo *Cf cantteneus flan or pretsere ilsnine, teppltoo air respirator. * laspiratort spnctfled for sign concentrations nay so ease at loner concentrations of asoostos. (Sea. Obi Stel cl and Kg). Pub. L tl-SOt at Sul m isos, tm in a uxc ass. SOT: Sec IV. Pub. L tl-aa. 01 StaL SS lao UJ.G iniacntrtn len. Ssovury of Labor's Order Ne *-a |ri fit 1S7MU ; STOO 0 6013