Document 1nx5ZDpdxLaomDGqDdE1X29o

. j*... CAMBRIDGE .TO.: H. _A.-Eschenbach FROM: P. M. Cvnnor 'VEG 000644 Jft 21 m\ PLAINTIFF'S \* j EXHIBIT i :WRG^754:r:v' DATE: 31 January 1S83 r;ub.!LCi .\stesios Re?.u;juors: Cr.runcky' an tivnale CHRONOLOGY z-i-s-a. In 1967, the American Conference of Covsrnmental Industrial- Hygi ir.iits (ACGIH) proposed a TLV of 12 fiber? (ore?ter than -5 microns . in lencjli:) per cubic centimeter of a;r. "flic Walsjr-Hca'ey Public Contracts Act of 1969 and subsequently the 0"cnpai:f;n?:l Safety & Health Administration (OSHA) in 1971 adopted the ACCIH-preposed TLV as legal standards. ;i "i:. ---- ' . - In November """1971 , a an cSe-yer.cy.-tempore."v v;r'.!crd to control concentrations of asbesfdts~erA<st v.aS suL-.-.lttcd tc-ObHA b'. .*-e AFL-CIO. As a r<etuj*t I^hartp-'titi?i'i-^ an et .ergc.^cy -temporary- star.. '^*!:^X^5;^fibers _45^eatecithands' microns !o length) per c:bk...centimeter v.iy. - '* for* an 8-hour time-v.F;ightcd: average \% v A) was published 'on Jletember.A^ 1971. ' - ' 'r' ' In 1972/ NIOSH published an asbestos erheriev document .which recommended a'standard of 2.0 asbestos fibers .-per cubic centimeter cf air based on a count of fibers greater than 5 microns in length. This standard was recommended with the stated belief that it would prevent asbestosis and with the open recognition that it would not prevent asbestos-induced neoplasms. Furthermore, data were presented which supported the fact that technology was available to achieve that standard and that the criteria would be subject to review and revision as necessary. - On June 7, 1972 , OSHA promulgated a permanent standard for occupational exposure to asbestos containing an 8-hour TWA concentration exposure limit of 5 fibers longer than 5 m/cc of air, with a ceiling limitation against any exposure in excess of 10 such f/cc. The standard further provided that the 8-hour TWA was to be reduced to 2 f/cc on July 1, 1976. As the result of a court case, OSHA decided that to achieve the most feasible occupational health protection, a reexamination of the standard's general premises was necessary. To this end, on October 9, 1975 , OSHA announced a proposed rule-making to lower the exposure limit to an 8-hour TWA concentration of C.5 asbestos fibers longer than 5 m/cc of air with a ceiling concentration of 5 f/cc of air foi up l*-* IS minutes. On December 2, 1975, OSHA requested NIOSH to reevaluate the infi-rmi-ticn .available-on the health effects ..of occupational.expesur*. lr. a* hestos .fibc rs and to advise OSHA'on the results of this study, so fu the;' ru!r--mailing * may':be_expected'as-tia!e.'goes cn. " ' . OSHA invited comments on the above proposed rule-nit king, and on February *1. S7. some 65 representatives from companies and trade yss.-iitrJcm. met and overwhelmingly endorsed ..s, "7 fir-^r-' lave! has Lein Cr- can be attained by r.'plicatic; cf engineering t/chnology but the proposed '`0.5 Jlber" level is unn-.cessar y, impractical arid icrus medical just.ftailion.: r . r - . - .. On December 15, 1976, NiOSK released its Revised Recommended A r.hastes Standard which stated the', the GSM A st^Mdaro should be set at tTie lowest level detectable by available analytical techniques. Since pha^e contrast microscopy is the only generally available and practical anslyiic.al technique at the present time, this level is defined as 0.1 f/cc on cn P-hour TWA basis with peak concentrations net .exceeding'0.5 f/cc`based on/aJ1Vminute sample period. -1-.. In the - tali of 1979,".-NIOSH and CSHA established an asbestos working group'whose mandate was -to re view all he:;!lh -effects data' since the 1976 NIOSH-Sfudy and to determine whether any char-iges-to the earlier recommendatiorv^its 0.1 f/cg-'j^w.hrrented. Ir. April of- 1.2 ?Cv^thc greup^. found that: - ,K -x There;^iSrd6`:.s5^5 exposure limit for asbestos; ' 't<~ r **':- -4- 2. --' All commercial and several non-commercial forms .cf asbestos cause disease; 3. OSHA should promulgate a -new standard oivitl f/cc as a maximum workplace exposure limit. RATIONALE The setting of an asbestos occupational exposure standard by OSHA in 1971 relied primarily on assessments made by the British Occupational Hygiene Society (BOHS). While there were numerous studies in the United States establishing that asbestosis was a major cause of disability and death among workers exposed'to asbestos dust, the British data ( 1968) contained information on both exposure levels and adverse health effects. The BOHS, in evaluating the information given to it on the recorded exposures in the asbestos textile mill and the infrequency of disease among workers exposed to dust at levels between 9-15 fibers/ml, came to the conclusion that, by lowering the permitted level from the present level of 12 fibers/ml to 2 fibers/ml as a time-weighted average, employees could be permitted to work in such environments for a full working life-time (50 years) without substantial risk of developing asbestosis. It was calculated that workers exposed to TOO fiber years/ml, that is, 2 fibers/*I for 1C years, ** fibers/mi for 25 years, or 10 fibei s/m! for 10 ycais, would ha . c a 1% risk of developing early signs of asbestosis. The asbestos standard set by OSHA in 1572 (5 f/cc to be lowered to 2 f/**c in 1S76) was thus based on the numerous U.S. studios and tht risk assessment done by the British Occupational Hygiene Society. OSHA (also HIOSH and the BOHS), however, noted that the standard was developed to prelect workers from developing asbestosis and that it was net possible at that time to specify an air concentration that would he known t; be fre? of cancer risk. In October of 1975, OSHA stated that: "`'Since the'promufeatien cf the U.S. parr.innent ; r.btstcs .standard, considerable r.cw information nas oern forthcoming on the toxic effects of asbestos. This has been in two areas: In the widening spectrum of cancers associated with asbestos exposure, and in various manifestations of asbestos disease in individuals exposed to relatively low concentrations of dust." * OHSA maintained that new data (from 1970-1975) revealed that a reduction of asbestos exposure to levels sufficient to prevent asbestosis is net sufficient in some instances to prevent asbestos-conccr. On Ihe ether hand, OSHA stated, a reduction of asbestos exposure to an extent sufficient to prevent asbestos associated can: er will olro prevent asbestosis. The OSHA '(V^975'J^ro; osed rule-making document ciTecJ many studio*. showing excess .duo. neoplasms in asbestos exposed >'ock*-> s. .Included^if* Afiese -.studies ywas a .follow-up evaluation. of; to? .learj--;.' Mentioned British _ study which showed higher levels of --ashes tcs-relaled . disease than was previously found or predicted to be found. r-- The data that was cited and the fact-that none of these -studies had demonstrated that a "no effect" or safe level ejdsted- ted-OSHA to endeavor to lower the standard to a level as low as feasible. OSHA proposed a level of 0.5 fibers/cc for an 8-hour TWA. While OSHA maintaned that, since there is no assurance of a safe exposure to a known carcinogen and there should be no detectable concentrations, the Occupational Safety and Health Act requires that the Secretary establish standards to the extent feasible. The OSHA proposed "0.5 level" was never promulgated because its feasibility was not proven. Future NIOSH and OSHA communiques still called for a lowering of the asbestos exposure standard to the lowest detectable level. PMC/cs Paul M. Connor