Document 2RvD8x599ZR6M58gDrmwnv0La

FILE NAME: WR Grace (WRG) DATE: May 24, 1977 DOC#: WRG347 DOCUMENT DESCRIPTION: 1977 Memo from ES Wood regarding Tremolite in Vermiculite GRACE ConiHuctien Prsducti Division PERSONAL AND CONFIDENTIAL 0362966S To: C. E. Brookes C. N. Graf From: E. S. Wood Subj : Tremolite in Vermieulite cc: R. M. Vining B.'A. Blessington C , Duecker V, R. Hanlon W. F. McCord L. Rosenblatt B. R. William J. W. Wolter May 24, 1977 The purpose of this memorandum is to discuss in s o w detail the nature of the tremolite problem as it Impacts our veraicullte business, and also to outline our plans for dealing vlth the problem. Theae plans are based on extensive product testing, analysis of alternative confi gurations of the Zonollte business, and consultation with legal counsel, including the Corporate Legal Division. . THE PROBLEM . Tremolite is present as a tramp mineral in our vermlculite deposits, and while most of it is separated from the vermlculite in the milling process, small amounts are carried to expanding plants and ul timately into finished products. Tremolite Is classified as asbestos and regulated by the Environmental Protection Agency (EPA), the Occupa tional Safety and Health Administration (OSHA), the Mining Enforceswnt and 15101*06 004289 C. E. Brookas/C. H. Graf -2- May 24, 1977 03629669 Safety Administration (MESA), the Consisner Product Safety Act (CPSA), and the Toxic Substances Control Act (TSCA) as a carcinogen. Although we have been working since 1971 to reduce crcmolite in our product, in our expanding plants, and in our mills, we have felt until now that crcmolite was mis* classified by OSHA and others as a form of asbestos. This was based on our understanding of the difference in physical characteristics of tremolite compared to other fibrous forms of commercial asbestos, as well as outside studies such as the animal study sponsored by Johnson & Johnson on a tremolite talc which showed no carcinogenicity. Two recent developments have changed our views oh this subject. First, an in-house study of mortality races among ex-esploysss at Libby Indicates that their .rink of lung cancer is five times the national average. In this connection, we have experienced asbestosis in 41.51 of the workers (with over 10 years' service) in Libby, as well as in 281 of the workers (with over 10 years' service) exposed to Libby ore in the expanding plants. (The experience at Libby is confused because all of the- aforementioned workers were exposed to high dust count levels in the old dry mill. The present Libby dust environment with the new mill represents a major change in this respect. Fiber counts have dropped from a level of above 30 f/ml on the average to a level below 5 f/ml. Also, the expanding plant employees mentioned have also been exposed to commercial asbestos in the manufacture of IK for a number of years.) Secondly, with respect to national safety regulations, the prior distinctions between "commercial asbestos" and "non commercial asbestos" (traap contaminants) are being erased as the general nature of the hazard of exposure to fibrous materials is more thoroughly studied. 15101909 004290 C. E. Brooke*/C. N. Gref -3- May 24, 1977 03623670 A great deal of controversy exists over what constitutes a safe level of exposure to a carcinogen. Most people would agree that safe levels are very difficult to establish. One view, taken by most regulating agencies, Is that since no safe level can be unequivocally demonstrated, carcinogens must be eliminated where there are acceptable substitutes. Where the carcinogen cannot be eliminated by substitution, exposure must be con trolled at the lowest level which can be technically achieved and reliably monitored, the opposing group makes a strong ease that no unusual health risks have been rigorously documented for asbestos exposures below 5 f/ml (8-hour tine weighted average), much less the present standard of 2 f/ml, or proposed scandard of .5 f/ml. In the presence of such controversy it is difficult to determine what poatura la appropriate for ua la establishing limits of exposure for our employees and customers. A mors dstelled dis cussion of the health hazards associated with asbestos exposure is contained in Appendix 1. The exposure problems that we have seen to date are limited to the fibrous type of cremolite that occurs in the Libby deposits. The tremollte associated with our deposits in end around Enoree, South Caroline * ' is largely non^flbrous. Since we have no evidence of esbestosis or other exeese health risk associated with asbestos exposure among employees working in South Carolina, we do not believe that the levels of exposure to our employees or customers utilizing materiel from South Caroline creates a health hazard of any kind. In the case of materiel from Libby, ve believe that lower levels of exposure ere required to assure the safety end well being of our employees. Moreover, regulations already proposed, when put into effect, will mandate lower levels. 15101910 004251 C. Brook*s/C. N. Graf 6 May 24, 1977 03629672 Dallas (550,000); Portland (5107,000); Dearborn (5197,000); and Omaha (5315,000). Since che steps taken co reduce fiber counts' to 2 f/ml, with proper plant maintenance, can generally bring fiber counts below 1 f/ml with appropriate peripheral equipment, we expect co achieve a level of 1 f/ml at all expanding plants by mld-1978. An additional $93,000 of capital will be required for peripheral equipment co meet 1 f/ml at the following plants; Easthampton ($17,000); St. Louis ($26,000); Little Rock ($50,000). These changes vlll be handled through a series of individual plant RCA's or shop orders, with the exception of Omaha spending which has already been approved under RCA E76-317 ($247,000 approved by che President on November 26, 1976), and RCA E76-311 ($68,000 approved by che CPD President on September 27, 1976). Excluding Omaha, che expanding plant capital spending totals $721,000 versus budgeted 1977 and 1978 figures totaling $666,000. In part, these changes are being undertaken now since they re present relatively small capital increments (above what would be required to reach the present mandatory levels) that will yield substantially lower exposure levels to our employees. However, it is clear that the levels which w* propose meeting will eventually be embodied in stricter state and federal standards. Moreover, it Is clear that che Federal Government * policy for the long run will be directed to achieving the lowest level which is technically feasible and which does not have an adverse impact on the economy as a whole. 15101912 004293 C. E. Brookes/C. N. Graf -7 May 24. 1977 03629673 Standards as low as .1 f/ml have been proposed by che National Institute for Safety and Health (NIOSH). While this was a proposal that has been made without regard for its economic impact or technical feasi bility, it is indicative of the general philosophy behind control of substances defined as carcinogens. 2. Product Labeling Based on the advice of corporate general counsel, we have decided not to affix asbestos warning labels on any of our expanded products which, in their normally intended use, do rot expose customers to fiber levels above those permitted by OSHA. Thus, no products made from South Carolina ore will require labeling. Subject to the results of additional job-site tests, no present expanded products using Libby ore will require labeling, with the possible exception of industrial grades for which we may not be able to identify and test all end uses. This policy is consistent with che posture of Johns-Kanvllle, the largest supplier of asbestos products in che U.S. and a leader in the field of asbestos safecy and health precautions. Effective July 1, 1977, all new packaging purchased will Include a general dust warning label printed on the package. . Zn Che case of consumer products, we are operating under the presumption that the present controversy over regulation of materials con taining asbestos will be resolved by che Consusr Product Safety Coenisslon (CPSC) in favor of a complete ban on consumer products containing asbestos fibers unless they can be shown to be "bound". Recent action of the CPSC 15101913 004294 C. E. Brookes/ C. N. Craf -8- May 24, 1977 03629674 in proposing a ban on drywall joint compounds containing asbestos, arcifical fireplace logs using free asbestos fibers, and spackling compounds containing tremolieic talcs eends to support our presumption of an eventual ban on unbound asbestos-containing consumer products. Equipment is being installed at 14 key planes at a projected cost of $130,000 (average of $9,300 per plant) using individual, locally approved shop orders. This equipment will permie us to apply a binder for our two major consumer produces -- Attic Insulation and Horticultural Vermiculite. Simultaneously with the installation of the equipment, we are in the process of choosing an appropriate binder and level of treat ment with the objective of reducing the use exposure for these products to a level of 1 f/ml maximum exposure and .2 f/ml on an 8-hour time weighted average basia. These ere levels chosen because we think they are technically achievable end are close (within e factor of 2) to the level which NXOSH proclaims to be the lowest level which cen be reliably monitored. It should be emphasised that theae steps are being taken to comply with the extremely stringent projected regulations, and not because we feel that the use of these products creates e serious risk for consumers. * Considering the brief and irregular pattern of use, we do not believe that asbestos exposure from our products causes an increased risk of health problems. However, there is a fringe of expert opinion, moat prominently and articulately represented by a well-publicized expert from Mt. Sinai (Dr. Sellkoff) suggesting that even brief exposures, presumably at high levels, can later produce mesothelioma. Mesothelioma is a rare form J5l0l9j4 004295 C. E. Brookes/ C. N. Gref -9- May 24, 1977 03623675 of lung cancer linked to asbestos exposure. For this reason, and the cxpeered stiff regulation of asbestos-containing materials In consumer products, we feel that it is prudent to develop a treatment for our con sumer products, even though it Is anticipated this will Increase our cost of manufacture by up to 15Z. Even chough we will not be labeling most of our products, we intend co notify customers who inquire that small amounts of tremolite are present in our end products with the exception of our mixed products. In the case of mixed products (MONOKOTE and soil mixes), tremolite is detectable only through the use of internally developed analytical procedures which require elaborate techniques not commonly recognized or employed in the scientific community for detection of asbestos. For this reason, we are talcing the position with all but authorized government authorities that our mixed products are "non-asbestos" products. Obviously, in responding to government inquiries we intend to provide specific data, which we have, that identifies trace levels of tremolite even in mixed products. It is our belief, for purposes of the law,that the amount of fibrous tremolite present in our mixed products is de minimis. Requests for written statements concerning the presence of asbestos in our products from customers will be answered by indicating chat we have small amounts of tremolite present in the product and by referring them to the OSHA regulations covering asbestos-containing products. 15101915 004296 C. E. Brookes/C. N. Graf -10- May 24, 1977 ZONOLITE PROFITABILITY IMPACT 03629676 Comparative financial analyses have been completed for the present Zonolite business and several alternative configurations which could be forced by future regulatory activity and/or our ability to meet future fiber standards. The base case and alternative case assumptions and financial comparisons are presented in Appendix 111. The following table suassarites key financial statistics for: 1.) the Zonolite 1977 budget and forecast, prepared in October 1976; 2.) a 1977 re-estimate completed in January 1977 reflecting adjustments to sales and gross margins based on the economic outlook at that time (used as the "base case" in Appendix III); 3.) a "most likely" future case reflecting additional capital spending for' fiber control, additional costs for binder treatment in certain products, withdrawal of certain consumer products such as Attic Insulation in the U.S., and labeling of the remaining consumer products (Case B in Appendix III). ($000) Budget 1977 Base Case Case BU) Budget 1980 Base Case Case B Net Sales $65,719 $63,495 $57,303 $92,639 $92,281 $80,232 Operating Profit 5,201 4,183 3,033 8,278 8,512 6,065 Profit After Tax 2,779 2,556 2,018 5,305 5,373 3,758 Total Capital Employed 1 Return on TCE $31,573 $30,891 $29,937 9.01 8.51 7.01 $37,613 $37,215 $34,328 14.31 14.61 11.21 (1) Case B presented in 1977 is for comparative purposes only. The full-year impact of assumptions in Case B would not actually be experienced in 1977. 1510191b 004297 C. Brookes/C. N. Craf 11 May 24, 1977 03629C77 Our projections indicace that even with che loss of our con sumer business (assuming the Canadian Attic Insulation business continues) Zonolite continues to be a viable business albeit at lower than forecasted returns. More selective internal use of South Carolina ore in place of Libby ore can largely eliminate the 10-50Z reduction in sales volume that would result from a requirement to label our products as containing as bestos. The reduction in sales from labeling is primarily the result of our being the first labeled product on a construction job site which would force contractors to comply with impractical OSHA regulations. ALTERNATIVE APPROACHES Considering the large potential liability that results from the sale of products that contain even a small amount of contaminant defined by the government as a carcinogen, it is reasonable to question whether there are alternatives to the proposed action. Our exposure to law suits cannot be Ignored. In addition, we are forecasting a continued demand for no return capital to be Invested In che business in order to meet increasingly tighter standards for asbestos fiber exposure, independent of whether a proven risk exists or not. Two obvious alternatives would be to seek divest ment of the business or to close Libby and retrench to South Carolina where the health issues are minimal (but not eliminated). Divestment of Zonolite has been considered in che past and been judged impractical. It is felt that no buyer could be found, capable of continuing to operate the business (with adequate capital resources) to give us an acceptable price for the business as compared to other alternatives. 15101917 C0429S C. E. Brookes/C. N. Graf -12- May 24, 1977 0362967S Closing of Libby and retrenching to South Carolina would require a drastic change in the basis on which the business is run. It is likely that we would be operating a regional business in the East, Midwest, and Southeast, rather than the present national business for Zonolite products. This alternative, if required, would be expeceed to produce a high return but substantially lower after-tax profits. For example, our projection for I960 for a regional business, without Libby, shows after-tax profit of 2.6 million dollars giving a 15.2Z return on the 17.2 million dollar Total Capital Employed. (This case is presented as Case C In Appendix III.) Large asset write-offs and interim operating losses would be Incurred to convert to this regional business basis. Ue now believe the most likely case for 1980, retaining Libby, but recognizing Che possible loss of consumer businesses to be a 3.8 million dollar after-tax profit, generating an 11.21 return on 34.3 million dollars of Grace Capital Employed. Our forecast indicates chat continuing to operate Libby and con tinuing to conduct a national business is a preferred alternative unless large amounts of capital are required to meet drastically tightened asbestos fiber exposure levels. Our best estimate is that a 1 f/ml standard for Libby would require 3.6 million dollars of additional capital. A tightening of the OSHA regulations covering our expanding plants co a level of .1 f/ml would require 6 million dollars of additional capical. Based on our present assessment of what is technically required, a stove to the standards of .1 f/ml in the expanding plants and 1.0 f/ml in Libby would make it uneconomical co continue operating Libby. 15101918 004299 C. E. Brooke*/ C. H. Cra -13- May 24, 1977 03629679 In the absence of such extreme (and unlikely) tightening of standards, our projections indicate that the best course ia continued operation of Zonolite from two mine locations. RISKS There are seven specific risks associated with tremolice in our workplaces and products which we assess as follows: 1. Harm to customers. We do not feel that our products create a hazard for normal end uses. The highest level of exposure is for Attic Insulation and Masonry Insulation. The high concentrations of upwards of 15 f/ml (15 minute maximum) for Attic Insulation and 12 f/ml (15 minute maximum) for Masonry Insulation that were observed in simulated tests early in 1976 have not been confirmed by the results of more recant testing in actual field use. (The present OSKA ceiling limit is 10 f/ml for any 15 minute period.) The maximum concentration in the case of Masonry Insulation observed in recent testing was 3.65 f/ml (IS minute maximum) and in the case of Attic Insulation was 4.28 (15 minute maximum). However, we have observed very large variations in simulated test results such that further improvement in Attic Insulation, in particular, may be necessary to be assured that we reliably fall below 10 f/ml maximum exposure during use. Due to the products' short and irregular periods of use, it seems unlikely chat we would exceed the 2 f/ml, 8-hour time weighted average, OSKA standard with Attic Insulation or Masonry Insulation. *3101919 004300 C. E. Brooke*/C. N. Graf -14- May 24. 1977 03629680 All ocher produces appear to be well below permitted levels, in most instances by a good margin. (See Appendix IV for representative test results.) 2. Harm to employees. The present level of axpoeure for our Libby employees (up to 5 f/ml TWA), while materially better than the harmful exposures before the new wet mill, still represents concern to us. Therefore, we will be undertaking an employee education prpgram as well as further reduction in the fiber levels to 2.0 f/ml, in order to reduce the risk of harm to our Libby employees' health. The reduction to 1 f/ml in the expending plants, which we expect to accomplish by mid-1978, should give us a comfortable margin of safety in concluding that there Is very low risk to our employees in the expanding plant work environments. The risk to expanding plant employees using South Carolina ore, as well as to the mine/mlll employees in South Carolina, is negligible. 3. Product bans. There la a high rlak chat our products will be banned in several significant uaes. We forecast chat our vermlculite consumer products, namely Attic Insulation, Horticultural Vermiculite, and Pool Base, will eventually be banned by the Consumer Product Safety Commission, and this has been assumed in the 1980 financial projections (Appendix III), Wc place our chances at 50:50 of binding the tremolite such that we could effectively argue that no fibers will be released during use, 15101920 004301 C. E. Brookes/C. N. Cral 15 Key 24, 1977 03623681 There Is also a high risk (30X) during the next 18 months that MONOKOTE fireproofing will be considered to fall within the ban in selected states (California, New York, Minnesota, Massachusetts, and Illinois) of fireproofing products containing asbestos, although it would appear that this is an unintended ban. Legislators in Chose states simply failed to consider trace tramp minerals when wording the prohibition against a product containing any asbestos for sprayed applications. Ue are actively working on a vermicullte free fireproofing material for introduction in mid-1978. . 4. Label requirements. # ' We believe that a decision to affix asbestos-warning labels to our products would result in substantial sales losses. This view is shared by Johns-Manville in the ease of their labeled construction products. It is further supported by J - M's experience with their tremolite tales. Based upon advice from corporate counsel, our products do not require labels if the OSHA limits are not exceeded in their intended use. This is also J-M's position for their own products. We believe chat all of our products fall below the limits established by OSHA and that we will be able to continue to fall below more stringent standards being projected, thus avoiding the need to label our products. Secondly, any change in interpretation which would require a labeling of selected products, such as Masonry Insulation, can probably be avoided by redistribution of the cleaner South Carolina ore and with drawal from selected isolated territories. 15101921 004302 C. E. Irookes/C. N. Graf -16- May 21*, 1977 03623682 Continued programs aimed at cleaning up the product should allow us to meet the projected tighter limits that may be imposed by OSHA in 1978 and 1980. 5. Increasingly restrictive standards and higher capital requirements to eeet the more stringent future standards. We believe there is a very high risk that standards will be come more restrictive requiring additional capital for continued operation of Libby and of expanding plants using Libby ore. In addition to the 1.9 million dollars which we propose to spend between now and mid-1978 to comply with asbestos fiber safety standards, an additional one million dollars is expected to be needed by 1980 in order to meet a projected OSHA standard of .5 f/ml. There is a risk, which we place at less chan a 201 chance, that additional investment of up to 10 million dollars would be required in order to reach a level of 1 f/ml at Libby ($3.7 MM) and .1 f/ml at expanding plants using Libby ore ($6.3 MM). Such a development would probably result in a decision to close Libby and the retrenchment of our business to a regional basis supplied entirely out of South Carolina. (See Appendix III, Case C for details of the financial impact of a decision to close Libby.) Adverse publicity There is a risk chat Crace will attract adverse publicity from national media concerning Che presence of asbestos in vermiculite. This 1810 W Z 2 004303 C. . Brook*/C. N. Graf -17- May 24, 1977 03629683 informacin is already being circulated within government agencies, such as OSHA and has been reported on a local basis in connection with the Louisa Councy dispute over the mining of vermicullce ore. Future steps, such as the development of a case for continued sale of Attic Insulation to the Consumer Product Safety Commission, will increase the risk of widespread adverse publicity. 7. General liability to employees, customers, and the public. Liability to employees is limited by the Workmen's Compensation Laws. However, we should expect Increased Workmen's Compensation rates in Libby as the number of disabilities increase among employees who have been exposed in the past to the high fiber concentrations of the old dry mill. Liability among expanding plant employees and the South Carolina mine/mi11 employees appears minimal. The risk of liability to customers is heightened by the decision not to label our products. Under the strict Liability criteria, we may be liable to customers who can demonstrate they (1) were exposed to asbestos fibers and (2) sustained personal harm. Based on advlee of corporate counsel, this risk is categorized as moderate. Moreover, it seems unlikely that bona fide cases of personal harm could be well documented considering the pattern of use and exposure levels of our customers. General public liability, steaming from the sale of consumer products, is a low-level risk with very high potential liability if it develops. While we have no evidence of any adverse effect of our products on consumers, neither can we offer convincing evidence that they are ab- 15101923 004304 C. E. Brookes/C. N. Graf -18- May 24, 1977 036296S4 solutely safe. Making such a case is handicapped by the number of "experts" who claim that there is no safe level with the inference that any exposure is potentially hazardous. This leaves u$ open to liability without a good defense over a broad range of alleged hazards. A decision to label our consumer products would eliminate Che risk of future lia bility, while exacerbating the risk of claims (mostly not bona fide) from past use of the product. E. S. Wood ESW/CGR Attachments 15101924 004305 APPENDIX appendix i 03629G85 MEDICAL EVIDENCE ON THE EFFECT OF ASBESTOS EXPOSURE Exposure to high concentrations of asbestos fibers results In increased risk to health of three different types: AsbestosIs is a scarring of the lungs that is a chronic condi tion appearing first in chest x-rays, usually after 5 or sore years of exposure. It can be reliably diagnosed from x-rays and is specifically identified with exposure to asbestos fibers. Lung cancer (bronchogenic carcinoma) can develop as a result of exposure to asbestos fibers or to other causes (such as smoking). It is difficult to diagnose due to the long latency period between initial exposure to asbestos and development of symptoms. Furthermore, since there are a number of causes of lung cancer, it is more difficult to establish a cause-effect relationship between exposure to asbestos fibers and lung cancer. Nonetheless, a great deal of work has been done which convincingly Indicates a relationship between an excess risk of lung cancer and exposure to high concentrations of asbestos (above 5 f/ml). A combination of exposure to high concentrations of asbestos fibers and smoking is more damaging than either alone. One study among asbestos workers has shown that a mkers have eight times the risk of lung cancer than non-smokers have. Mesothellcuna is a rare fora of cancer which can occur either in the lungs or in the stomach. It can be specifically diagnosed only by taking a biopsy of the affected organ. It is specifically associated with asbestos exposure. Around 851 of cases diagnosed as mesothelioma occur in patients who have a history of exposure to asbestos. IDIOI^6 004306 appendix z -2- 03629686 Although Cher* is disagreement between experts on this point, Che determination of an increased risk of asbestosis may also be indica tive of an increased risk of lung cancer. For purposes of assessing the risk to our employees, the only practical indicator is the incidence of confirmed eases of asbestosis. This is due to the extreme difficulty of determining the cause of cancer in any group of people considering the long latency period and general lack of specificity between lung cancer and any tingle cause. The ex ception to this would be cases of mesothelioma. H ot-ever,, we have no reports of mesothelioma even at Libby. As a result of the particular philosophy employed by govern ment agencies to regulate carcinogens, as well as the experimental diffi culty of establishing safe levels, very little scientific work is available to help identify the health risk posed by exposure to low levels of asbestos fibers (under 5 f/ml). There are three sources of information outside CPD which purport to Indicate that asbastos fibara cause increased health risks even at low concentrations. The first is a study among hard rock miners In Idaho (Gillam et al.) which indleaees an increased risk of lung cancer in the presence of asbestos fiber exposures of around 0.24 f/ml. However, this study is confounded by the presence of ocher potentially carcinogenic materials, notably arsenic * containing compounds and radon daughters. A still unpublished study of a larger group of the same miners (McDonald et al.) has indicated no increased 15101926 004307 APPENDIX I 3 03629687 mortality risk from silicosis. This particular evidence of a hazard associated vith low level exposures would seen to be seriously impugned. A second purported indication of the hazard associated vith low exposure levels is an increased risk of lung cancer among relatives of asbestos miners. However, more recent measurements Indicate that fiber exposures in home environments of asbestos workers can be high and therefore this probably does not represent a low level exposure environment. The third collection of evidence is of mesothelioma (not other asbestos-related diseases) in individuals and in animals exposed to high concentrations for brief periods of time (as little as 8 hours). The cases in men are few in number typically involving one or two individuals with unknown but probably very high exposure concentrations. Due to the small number of cases, definite cause-effect relationships cannot be drawn. The cases among animals are at extremely high dosage levels in species which are especially sensitive and,therefore, extrapolation to the effects on man are not well-founded. In spite of the lack of hard evidence, there ir a respected group of professional researchers who express the opinion that exposure to levels as low as 2 f/ml (8-hour TWA) create an increased risk of cancer in men after 30 or more years of exposure. Kesults of our own in-house epidesdological studies indicate that conditions which existed in the old dry mill in Libby (34 f/ml TWA) end in unregulated expending plants using Libby ore (29 f/ml TWA) created e health hazard to our employees. Among present employees with 10 or more 15101927 004308 APPENDIX Z -4- 036296S8 years of service who would have been exposed to che conditions In che old Libby dry Bill, 41.5% exhibit asbestosis. Moreover, there is a five-fold Increased risk of lung cancer among retired and ex-employees who worked in Che Libby mine (as compared to the general population). We are encouraged by the absence of any new eases of asbestosis found at the last annual check-up at Libby. Among expanding plane employees, the high employee turnover and variety of past exposures make conclusions difficult. Among 9 employees with 10 or more years' service in planes which have not used Libby ore, there la no Incidence of asbestosis, even though several of these plants have previously used commercial asbestos in some products. Among 14 employees with ten or more years of service in expanding plants which have used Libby ore, 28% exhibit asbestosis. However, any cause-effect conclusions are confounded by the fact that all of these plants have used commercial asbestos in the past. Chest x-rays for the 77 employees at our Enoree mine/mill give no indication of adverse health effects from exposure to the lower level of tremollte fibers (0.8 f/ml) found in South Carolina. While there is Incidence of positive chest x-rays in 12 employees (16% of total), only one ease is consistent with exposure to asbestos. That particular employee worked for a great number of years exposed to commercial asbestos in another Zonollte location. Of the 12 positive chest x-rays, 5 stem from previous cotton spinning mill exposure which produces "brown lung" disease. There Is no indication of excess mortality due to lung cancer among the South 15101926 004309 APPENDIX I -5- 03629689 Carolina mine employees. Since the South Carolina mine has only operated for 29 years, there is still the possibility of extremely long latency periods before excess mortality would be observed. As very little published medical evidence exists for tremollte exposures, as opposed to the commercial forms of asbestos, we have sponsored animal studies on tremollte and a mixture of vermleullte and tremollte to determine whether tremollte la carcinogenic. The cast animals have concluded 400 days of treatment and are scheduled to terminate after 730 days. Uhile no definite conclusions can be drawn from the results to date, indications are that our tremollte creates less of a problem than eosaereial asbestos. As we have not yet completed the "critical" period of the animal studies,between 370 and 450 days, the lack of a significant difference in mortality between the test animals and the control group is not yet meaningful. Results of this study should be complete and available by October 1978. We have sought and obtained advice from several outside profes sionals with respect to what tremollte levels create a hazard. Dr. William E. Smith of Fairleigh Dickinson University has responded (Appendix V), indicating that notwithstanding the "new evidence" presented by OSHA and NX0SH there is no convincing evidence of aa excess risk to health from low level asbestos fiber exposures (below 5 f/ml). Dr. HacMahon, Professor of Epidemiology at Harvard University, has questioned the conclusions of a leading epidemiologist, Dr. Selikoff of Mt. Sinai, that exposures to low 'levels are potentially hazardous. More- 15101929 004310 APPENDIX I -6- 03629690 over, he indicates that an unpublished study of shipyard workers in the Pearl Harbor Navy Yard who have been tracked since 1943, indicates no excess risk of cancer mortality contradicting the evidence presented by Sellkoff. He derides Selikoff's statements with respect to low exposure level hazards as being unprofessional and not well-founded scientifically. Dr. Enterline of the University of Pittsburgh has proposed a mathematical model which closely fits the observed relationship between mortality race and time of exposure among the group of 17,000 shipyard workers studied by Selikoff. We are in the process of using this model to predict the effect of exposure levels of 1 or 2 f/ml. Even assuming that crcmolite fibers are as biologically active as commercial chrysotile asbestos (an unduly pessimistic assumption), preliminary indications are that the increased mortality risk from lung cancer as a result of a 50-year exposure to 2 f/ml is only 101 above chose not exposed to asbestos fibers. Discussions with Johns-Manvllle revealed chat two "modern" asbestos fabricating plants (one in Texas and one in California), built in 1956-57, show no cases of asbestos-related disease among their employees. Exposures at these plants have been consistently below 10 f/ml (8-hour TWA), probably in the 2-5 f/ml range, with exposures during Che 70's consistently below 2 f/ml. This suggests no excess health risk at concentrations up to 5 f/ml (8-hour TVA). Amidst such conflicting scientific opinion, any conclusions which we draw must necessarily contain large elements of personal judgment and at least some level of uncertainty. Nevertheless, we must establish levels of 15101930 004311 APPENDIX I -703629691 exposure calculated to protect both employees and customers from excess health hazards. Accordingly, we have concluded that in a regulated and monitored environment such as our plants, a reduction in exposure to 1 f/ml creates a worthwhile margin of safety over the present OSHA standard of 2 f/ml for our employees. A level of 1 f/ml is not expected to have an adverse health effect. A level of 2 f/ml, while probably not hazardous, does not have an acceptable margin of safety and will be reduced if economically feasible. No customers or employees will be exposed knowingly to concentrations above a level of 2 f/ml without adequate warning of the potential hazards involved. Johna-Menville also salects 2 f/ml as s limit balow which there la "no excass risk of asbestos-related disease" (compered to those who are mot exposed to asbestos). ' In unmonitored environments, involving dally use of our products, such at construction altas, a typical exposure from our products of .5 f/ml (TWA) is not eonsidtrad a hazard. With the exception of mixed horticultural products, exposure levels for users of our product are above background levels. It is not likely chat any improvement which we may make will reduce the exposure of users to levels as low as background. However, our long-range objective will be to reduce customer exposure levels to "the lowest limit at which asbestos fiber concentrations can be reliably monitored". According to NIOSH, this level It .1 f/ml on an 8-hour time weighted average basis and .5 f/ml for any 15-minute period. 15101931 004312