Document RJxzrd60n7G8qEJzN2JomDN5n

UNION CARBIDE CORPORATION Nuclear Division New York, N. Y. MEMORANDUM To: Messrs. T. Dougherty R. A. Miller. R. Stobaeus T* R. van Fleet DISTRIBUTION W. T. Cohan Q J. A, Riddle E. W. Haskjfl! L f. Crow 0. C. firice . '6. Q HC. Wet f. Vessels .... ^LSShiftejs January ^1965 cc: Messrs. K. W. Lentz A. E. Pufahl G. S. Jordan H. F. Reichard N, J. Setter R. G. Woolery t/j. A. Riddle Dr. C. U. Dernehl Subject: ASBESTOS TOXICOLOGY REPORT Gentlemen: - i Recently several reports were given at technical meetings and summaries of them carried by the national wire services concerning possible carcinogenic properties of asbestos. Some of you may have received questions from your customers on this subject. In order to counteract any serious problems or worries before they get out of hand, we have asked Dr;- C. U. Dernehl, Director of Toxicology, Union Carbide Corporation, to formulate a statement for us. A copy of his statement is enclosed. Additional copies can be obtained from me or you may make your own copies if you wish to pass them on to interested customers. You will note that, in essence, the report states that good housekeeping - such as would be required in any dust-producing operation -- should be sufficient to prevent any problem with asbestosis. You will also note that he mentions use in a wet system -- which cercainly applies to the paper mill -- and a pellet form -- one of the strong points of our asbestos -- as additional means of minimizing any potential problem with the product. Further, other asbestos producers and those acquainted with the subject feel that the original data upon which the cancer-producing report was based aid not take into account any outside influences, such as smoking or corrosive atmospheres, which also might produce cancer. Here, it should be noted that much asbestos usage considered in the technical papers is in conjunction with tar and pitch compounds which are known to contain carcinogenic materials. -Ao?OOj UCC 020713 UNION CARBIDE CORPORATION CHEMICALS Si PLASTICS P. O. BOX `K* -- KING CITY, CA. SSSSO ASBESTOS TOXICOLOGY REPORT It has been known for many 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 related 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. It is now generally accepted that a man can work a 40-hour week for a lifetime without developing asbestosis if the asbestos dust particle count is kept at or below 5 million particles " per cubic foot of air. This dust concentration of 5 million particles per cubic foot of air is the Threshold Limit Value for asbestos, and no cases of asbestosis are known to have occurred when exposures have been maintained at or below this level, despite large-scale utilization (now approaching one million tons per year In the U.S.A.). 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 duBt concentration must be from 8-10 million particles per cubic foot 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. Re cently 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 major manufacturer of asbestos products who also mines asbestos has not been able to show an increase in cancerous growths in men working where dust concentrations were maintained at the Threshold Limit Value. 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 in the system are necessary. Pelletizing is sometimes used to improve the handling characteristics of otherwise dusty materials. Where satis factory containment to Btay within the Threshold Limit Value is 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 paper manu facturing, it would be desirable to know the dust concentrations where the asbestos is dumped from bags into the pulp slurry. Concentrations should also be determined where dusting occurs in finishing products. While initial dust determinations 407009 UCC 020714 should he 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 examinations for workers are 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 paper products would be harmless to the consumer. Total , dusting would have to be well in excess of any levels acceptable to the consumer for the asbestos concentration 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 appro priate precautions, ' Carl U, Dernehl, M.D. Director of Toxicology Union Carbide Corporation K. S. Lane, M.D. Assistant Director of Toxicology Union Carbide Corporation retyped JLM/cg 1/7/69 A UCC 020715 o ;* n -o ^ w - ii. -"it J i ^ 270 PARK AVENUE. NEW YORK, NEW YORK 1C017 ra i-.s'-.-fle; Messrs: jn ,,zp t io C. Benjamin T. F. Frangos B. E. Godard J. L. Myers J. A. Riddle N. J. Setter J. T, Sinclair J. R. Stickney W. S. Young D ail Originating Dept. Antwarlfljj loflar data Subjacf April 3, 1969 Medical Department Asbestos to ll.c.c. CH1H. St PLASTICS Gentlemen: Both because of changes in regulations and availability of " data developed after the issuance of our report in 1964, Dr, Dernehl and 1 have revised the asbestos memorandum, A copy of the revision is enclosed. The major changes are the decrease in the Threshold Limit Value from 5 million particles per cubic foot of air to 2 million particles per cubic foot of air. {There is also a provision for another method of counting but it does not appear applicable to our short fiber asbestos.) We briefly discuss mesotheliomas, but data is too scanty as yet for a definite policy to be established. It is worth mentioning that the American Conference of Governmental Industrial Hygienists considered in 1968 a requirement that airline respirators be required for all contact with crocidolite asbestos. The resolution did not pass, but may come up again in future meetings. Any questions or comments will be welcome. Very truly yours, KSL:lk Enclosure Ao?084 UCC 020716 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 as asbestosis and 'was related 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. 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 air, even if this exposure con tinues 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 ACG-IH ('which sets she 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 she 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 UCC 020717 2- - beam of- light causing a Tyndall effect is present. Usually the dust concentration must be from 8-10 million particles per cuibc foot (MPPCF) before its presence it 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 wish histories of only slight exposures, and char as much as twenty to forty years earlier. There is considerable evidence that crocidolite is most frequently 4 associated with mesotheliomas. From the data available it appears chat the TLV of 5 MPPCF is not low enough to protect against mesothelioma, and it is quite possible that 2 MPPCF is not, either. Research on she problem continues. 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. 4 UCC 020718 wet processes where possible, and adequate exhaust ventilation whore openings in 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 is 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 paper manufacturing, it would be desirable to know the dust con- . Generations where the asbestos is dumped from bags info the . . pulp slurry. Concentrations should also be determined where duscing occurs in finishing products. While initial dust decerminations should be made am frequent intervals, once the level has been established as satisfactory, the frequency may be extended zo occasional tesvs to assure continuation of a satisfactory condition. Pre-employment and periodic physical examination of 4. workers are 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 paper products would be harmless to the consumer. Total dusting would UCC 020719 07087 havs to bo well In excess of any levels acceptable to the cons-, wo for the asbestos concentrations to approach the Threshold Limit Value. In conclusion, while asbestos dust in excess of the .d Limit Value is potentially harmful. many other an.: s encountered in industry, it is as readily controlled as other such dusts and it can be used safely appropriate precautions, Industrial Medicine And Toxicology Department Union Carbide Corporation UCC 020720 4?o 88 2- You should have this statement available for any questions which might arise from your customers. If appropriate in your judgment, perhaps it should be discussed with certain customers who have not yet raised the subject. I do not feel we should make a big issue of it thereby drawing unnecessary attention to the subject since the conclusions are still questionable.' If you have any questions, please discuss them with me. T.J.Hall/dk enc. UCC 020721 A07Q04- UNION CARBIDE CORPORATION 270 PARK AVENUE, NEW YORK, N. Y, 100:7 ASBESTOS TOXICOLOGY REPORT It has been known for many years that some persons working in asbestos production wars prone to develop a disabling lung disease. In time, this condition became known as asbestosis and was related to ex posure 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. It is now generally accepted that a man can work a 40-hour week for a life time without developing asbectccic if the atl istoc each particle count is kept at or below 5 million particles per cubic foot of air. This dust concentration of 5 million particles per cubic foot of air is the Threshold Limit Value for asbestos, and no cases of asbestosis are known to have occurred when exposures have been maintained at or below this level, despite large-scale utilization (now approaching one million tons per year in the U.S.A.). 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 before its presence is visible in aver age lighting conditions. -, . Several years ago, it was reported that there was an increase in the incidence ox 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 major manufacturer of asbestos products who also mines asbestos has not been able to show an increase in cancerous growths in men working where dust concentrations were maintained at the Threshold Limit Value. 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 in the system are necessary. Pelletizing is sometimes used to improve the handling characteristics of otherwise dusty materials. Where satisfactory con tainment to stay within the Threshold Limit Value is 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 paper manufacturing, it would be desirable to know the dust concentrations where the asbestos is dumped from bags into the pulp slurry. Concentrations should also be determined where dusting occurs in UCC 020722 A0700b -2- finishing products. While initial 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 examinations of workers are 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 paper products would be harmless to the consumer. Total dusting would have to be well in excess of any levels acceptable to the consumer for the asbestos concentration 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. Carl U. Dernehl, M.D. Director of Toxicology K. S. Lane, M.D. Assistant Director of Toxicology UCC 020723 A07006 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 related 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. 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 air, 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 ACGIH (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 crocldolite 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. ^07 007 UNION CARBIDE CORPORATION CHEMICALS AND PLASTICS * 270 PARK AVENUE N Y N Y 10017 UCC 020724 ' ' ' ' 2- - 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 in 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 is 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 initial 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 are 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 consumer. Total dusting would have to be well in excess of any levels acceptably 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 020725 4 7008