Document zzaN3YxR4GQvKVO8Gxd97J0QR

U Li Lj . i LJ ;J iJ th i INTERNAL. CORRESPONDENCE union carbide corporation Xk fNumsi Comport? lOcOftOfl Mr. J. A. Riddle Mining & Metals King City, California M. P. Ballmer F. J. Shortsleeve Oaf Originating Oap#r Answering lertv cfofa Subject 270 PARK AVENUE, NEW YORK. NEW YORK 10017 D!CT1!SUT!ON September 9, 1970 1 A R, '*,. . R. O. Medical Department F , RJ. :` 3l R. C. J..'.,. / A./;.. ; K. A. K. VVc-jf ' R. Rivsra Dr. Lane and I have discussed the question of using asbestosd. Sc.ve!! in rice paper for cigarettes and cigarette filters, and we view this D. Garcia use with a very considerable amount of concern. While it is possible that asbestos in a cigarette filter could be bonded with other materials so that none could escape into the air stream drawn through the cigarette, there would always be the possibility of some escaping and being drawn into the lungs where it might lead to the development of cancer to the lung. This possibility is made more serious by virtue of the-fact that it has been demonstrated that asbestos workers in the United States apparently do not develop cancer of the lung unless they also smoke cigarettes. So you have here a situation in which an individual is exposed to asbestos and cigarette smoke at the same time. The implications for developing cancer of the lung are obvious. As far as the question of asbestos in the cigarette paper is concerned we think it should be pointed out that the ash from such a cigarette would contribute to the atmospheric contamination of a room with asbestos dust. We are already concerned with the potential environmental contamination which would result from burning papers fabricated with asbestos in incinerators. This proposed use in cigarette papers brings this hazard even closer to people, and we do not believe it is an appropriate use for asbestos. Very truly yours. CUD: lk C. U. Dernehl, M. D. Associate Medical Director 4 7089 UCC 020764 >I ASBESTOS TOXICOLOGY REPORT It has been known for years that some persons working in asbestos production were prone to develop a disabling lung disease. In time, this condition became known as asbestosis and was relsted to exposure to high concentrations of asbestos dust. With further experience, it was found that men could work with asbestos without development of lung disease if dust ,- concentrations were kept below a certain level. 'V It has been generally accepted that a worker will not develop asbestosis if he Is exposed to no more than 5 million particles per cubic foot of sir, even if this exposure continues for his entire working lifetime. Although no cases of asbestosis are known to have occurred when exposures have been maintained at or below this level, the ACCIH (which sets the threshold limit value (TLV) in the U. S. A.) has Indicated they intend to lower the TLV for asbestos to 2 million particles per cubic foot in an effort to increase the safety factor incorporated in the limit. The U. S. Department of Labor has already issued a regulation under the Walsh-Healy Act placing the TLV for asbestos at 2 million particles per cubic foot for public contracts in which they have Jurisdiction. This concentration of dust is generally not visible in the average work area unless a beam of light causing a Tyndall effect is present. Usually the dust concentration must be from 8-10 million particles per cubic foot (MPPCF) before its presence is visible in average lighting conditions. * .. . Several years ago, it was reported that there was an Increase in the Incidence of cancerous tumors, especially of the lung, associated with asbestosis. Recently there have been reports of some cancers occurring in individuals exposed to asbestos dust, but who have not developed clinical asbestosis. It is believed by most authorities that these cases have been associated with exposures significantly exceeding the Threshold Limit Value. A type of cancer named mesothelioma has been noted to be associated with asbestos exposure in recent years. These tumors, while rather few in number to date, may occur in individuals with histories of only slight exposures, and that as much as twenty to forty years earlier. There is considerable evidence that crocidolite is most frequently associated with mesotheliomas. From the data available it appears that the TLV of 5 MPPCF may not be low enough to ^protect against mesothelioma. Research on the problem continues A UNION CARBIDE CORPORATION CHEMICALS AND PLASTICS 270 PARK AVENUE. N.Y..N.Y. 10017 UCC 020765 Control of asbestos dust exposure is therefore necessary. The control methods.are the standard ones applicable to a variety of dusty operations. They include closed flow systems, wet processes where possible, and adequate exhaust ventilation where openings n the system are necessary. Pelletizing is sometimes used to improve the handling characteristics of otherwise dusty materials. Where satisfactory containment to stay within the Threshold Limit Value la impractical or impossible, efficient and reliable respirators are available for the protection of the employee. A program of environmental monitoring is highly desirable to determine that Threshold Limit Values are not being exceeded. In manufacturing industries it would be desirable to know the dust concentrations where the asbestos is dumped from bags into the process. Concentrations should also be determined where dusting occurs in finishing products. While initiel dust determinations should be made at frequent Intervals, once the level has been established as satisfactory, the frequency may be extended to occasional tests to assure continuation of a ' satisfactory condition. Pre-employment and periodic physical examination of workers ere desirable. These should include chest X-rays to insure that the worker has. no chest condition prior to work with asbestos and to determine that no lung changes are resulting from work with asbestos. . It is believed that the addition of asbestos at the proposed levels during the manufacture of products would be harmless to the consuemr. Total dusting would have to be well in excess of any levels acceptable to the consumer for the asbestos concentrations to approach the Threshold Limit Value. In conclusion, while asbestos dust in excess of the Threshold Limit Value is potentially harmful, as are many other dusts encountered in Industry, it is as readily controlled as other such dusts and it can be used safely with appropriate precautions. 5/8/69 Industrial Medicine And Toxicology Department Union Carbide Corporation UCC 020766