Document DvJLrOgrrrmwp2nV0wNdadKmM

FILE NAME: WR Grace (WRG) DATE: March 24, 1983 DOC#: WRG335 DOCUMENT DESCRIPTION: 1983 Office of Toxic Substances submission to EPA from HA Eschenbach OFFICE OF TOXIC SUBSTANCES CODING FORM FOR GLOBAL INDEXING REV. 7/27f Microfiche No. (7) Doc I.D. [ 98 -- 2 Case No.(s) I OTS 0503695 7 7 No. of Pages Old Doc I.D. 3 EH(p - 0 3> - (jf ' Date Produced (6) | 6 Check One : Publication Pub/Journal Name Date Rec'd (6) 1 f3 2. S~ P 3. 7 Conf. Code N DInternally Generated_____ jjfExternally Genen Author(s) i Organ. Ne--.. ifj & 4- Dept/Diy ) P.O. Boxi _ MID No. (7) 1 13 Street No./NameI Q>Z ifi/r-ZrTBMoE f i^ Statel i^i p 16 Zij a , 17 Countryl 19 D & B NO. (11) 1 Contractor I Doc Type | /( X Doc Title 1 I fi L t .s H fi.fi C t: ^ G fi ..... ./ / * . Sot ^ M is s io n / O f d>fi r / } orJ Ve r m i c o l i t e A rJfi r r e m o l l r e /vxfs* l /fi>i/r To erf i s T fire ^ B A /r TSc S tficT Tft/ DATED 4>4S& 3 Chemical Name (300 per name)| o r Xfi/TEfiWo r f i reo a/ x ^ e W ITH EPA fiE&PbNSE 25 CAS No. (10)1 1fERM tcoLo r e ASESTDS 1TS3(c-C S- 6 I 1 02/14/1996 EPA TSCA DOCKET i GRACE March 24, 1983 W.R. Grace & Co. 62 W hittemore Avenue Cambridge, Mass. 02140 1617) 876-1400 cCoO EPA/0TS TSCA PUBLIC FILES Document Control Officer Chemical Information Division Office of Toxic Substances (WH-557) U.S. Environmental Protection Agency 401 M Street, S.W. Washington, D.C. 2C46C Dear Sir: ro en BY HAND f - Z2>4-m This information is being submitted to provide technical compliance with BPA's Statement of Interpretation for Section 8(e) of the Toxic Substances Control Act, even though the information does not, in our judgment, scientifi cally demonstrate that our products as currently manufactured and distributed in commerce create a substantial risk. The information contained herein reflects past workplace /conditions at our Libby, Montana mine and mill, conditions which do not exist in today's workplace environment and have not existed since at least 1976. W. R. Grace & Co. (Grace) mines and mi'Is vermiculite in Libby, Montana. Mining and milling at L U b y began in the 1930's. Grace purchased the operation in 1963. Presently, Grace employs 170 people at Libby. The Libby vermiculite deposit contains tremolite, an asbestiform materiou. as a contaminant. This fact has long been known to regulatory agencies and our employees. Our ore beneficiation process, which has been viewed by EPA representatives, is designed to significantly reduce this contaminant. Dust exposure levels at the Libby mine and mill were very high in the years prior to 1963. After the acquisition by Grace conditions gradually improved. In September 1974 a new wet milling facility was placed into operation followed by further major process and operational improvements in the mill, mine and other areas which improved working conditions significantly. Lack of technology applicable to vermiculite milling required time-consuming research to overcome unique technical problems in the design of this new mill. Since the 1974/1975 period, exposures have been dramatically lowered and at present average less than 0.2 fibers/cc (0.01-0.9 fibers/cc range). (The U.S. Bureau of Mines measured a range of 13-71 fibers/cc during a 1971 survey of the facility and it is likely that prior to 1970 fiber levels exceeded those amounts.) 000002 02/14/1996 EPA TSCA DOCKET Document Control Officer - 2- March 1983 A medical surveillance program has been evolving at Libby since 1959 when chest X-rays were first completed on all employees. Chest X-rays have been repeated annually since 1964. In the period 1974/1975, annual pulmonary function testing was .dded and in 1978 health status questionnaires became part of the program. Results of the testing are available to employees and/or to their physicians. The Libby employee popi "ation has a history of both a large number of smokers (about 75%) and relatively heavy individual smoking histories (most employees smoked a pack or more per. day.) Based upon the recognition that smoking and asbestos fiber exposure can increase the incidence of disease, Grace, in 1978, banned smoking at all Company facilities in Libby. Programs have been organized to help employees stop smoking, and the smoking population has been reduced to 25% of the staff. All new hires are required to be nonsmokers. The National Institute of Occupational Safety and Health (NIOSH), acting at the request of the Mine Safety and Health Administration (MSHA), began a study in March 1982 of the effects of tremolite exposure upon present and past employees at Libby. This is a cooperative effort and we have made our data available to NIOSH. Grace has also developed estimates of historical individual worker exposure 1-ofAntlv bequn compilina other emplovee data with these estimates of exposure WCSSti "is also developing their own exposure estimates so that each of us may use the other's estimates for cross-comparison purposes which, we hope, will provide a more precise final product. As a result of our data collection and evaluation we have developed some preliminary data relating to the effects of tremolite exposure at Libby. At this time we are unable to make any final judgment as to whether these data on the effects of tremolite exposure are consistent with reports in the scientific literature. We do believe, however, that it corroborates written scientific opinion on the effects of exposure to asbestiform material and that it is within the realm of expectation for a mining and milling population, having exposures at the levels which prevailed at Libby in the past. In some respects the data are similar to what has been reported in studies of talc mining and milling operations in which the talc contained tremolite and other forms of asbestos. 02/14/1996 EPA TSCA DOCKET 00000 Document Control Of icer - 3 - March 24, 1983 Despite the uncertainty as to the meaning of the data, we have nonetheless decided to submit this information because of (1) the expressed interest of EPA, NIOSH, OSHA and MSHA in determining whether the various asbestiform materials induce different medical effects, and (2) ongoing agency investigations as to whether current asbestos exposure standards are adequate. Our preliminary information indicates that of 109 known deaths of former Libby employees, the cause of death for 16 Mas listed in death certificates or insurance claim forms as lung cancer, and for two others the cause was listed as mesothelioma. At this time we do not have sufficient medical information or sufficient occupational and personal history data in these cases to make a judgment as to the cause of these illnesses. In addition, based upon our individual exposure estimates, it appears that certain of our employees whose work history predates the new mill and who have a cumulative exposure of less than 100 fiber years show signs of asbestos-related disease. All of these employees had exposure levels of more than 2.0 fibers per cc for varying periods of time p H or to the new mill. There are several methodological problems which have prevented us from making any preliminary judgments based on this data. The first is that the information involves past workplace conditions. These conditions do not exist in today's workplace environment. For instance, all of the employees who show signs of asbestos-related disease were employed prior to 1976 when fiber levels were significantly higher than they are today. In contrast, our preliir.inary data shows none of the current employees h 'red since 1975 have asbestos-related disease. Also, there are those who question the validity of using cumulative exposures (averaging periods of significantly high exposure with later low exposure periods) and the fiber year concept as a proper basis for evaluating the effects of asbestiform material exposure. In addition, as indicated above, the vetv high percentage of smokers and former smokers among our employees t-akes it difficult to draw conclusions. Decause of the difficulty in interpreting this informa tion, we have had a preliminary discussion with and plan to retain Drs. J. C. McDonald and A. D. McDonald of McGill University, Montreal, Canada to undertake a thorough analysis of the Libby data. We hope that this will enable us to reach a scientifically sound conclusion based upon our historical data. We will also continue to cooperate with NIOSH in their study. 000004 Document Control Officer - 4 - March 24, 1983 Finally, we wish to emphasise that we have no reason to believe there is any risk associated with the current uses of Libby vermiculite-containing products. Very truly yours, Director of Health, Safety and Toxicology HAE/MS cc: Robert Wheeler and Harlan Amandus, NIOSH 02/14/1996 EPA TSCA DOCKET 000005