Document 2jENzN4JMkvQbgz59oGe7Q9NN

DRAFT - HBR 4/11/75 Mr. Thomas F. Anderson Designed Products Department Dow Chemical, U.S.A. Freeport, TX 77541 Dear Mr. Anderson: This is the summary of our discussions with OSHA on medical examination requirements in accordance with your request to Mr. J. E. Walsh. As you may recall, at the SPI meeting in Washington we provided asbestos fiber count data taken during the sanding and grinding of various polyester-fiber glass objects containing small amounts of "Calidria" asbestos RG-244. The counts were made by the OSHA procedure with all particles longer than 5p with an L/D ratio greater than 3 that could possibly be asbestos included in the count. It was also stated that we felt that most, if not all, of the fibers included probably were not free asbestos but we knew of no generally accepted analytical technique to prove this. Although the dust counts reported were low, i.e., less than 0.4 fiber/cc, they were distinguishable from background. This left the question as to which employees in a shop that was fabricating objects from asbestos containing polyester resin would be required to have medical examinations under current OSHA regulations. It was agreed that Union Carbide would try to obtain a clarification on this matter from OSHA. Mr. Lewis Cox, Special Assistant to the Assistant Secretary, OSHA helped arrange meetings in Washington with Mr. A. Reis, Senior Representative from the Office of Standards Development and Mr. C. McClure, Chief Compliance Officer, OSHA. Mr. W. C. Thurber, Product Manager for "Calidria" Asbestos represented Union Carbide. Mr. Reis stated that they now expect to publish the proposed changes in the standard about mid-May. If public hearings are requested, as expected, this would move the promulgation of the final regulations to about the end of 2- - the year. He was very careful not to provide any specifics but did say that the medical examination ambiguity had been cleared up in a way that should be satisfactory. The original NIOSH Criteria Document recommended a cutoff exposure level below which examinations are not required of one half of the allowable levels. It is our impression that something like this will be proposed for the revised regulations. Mr. McClure stated that their definition of "exposure to asbestos" meant any exposure above the background level. On the advice of the Solicitor General's office, there is nothing they can do now to alter this. When the proposed new standards are published, he indicated he would consider putting out a guidance directive to their field people but made no firm commitment to do so. It is clear that OSHA is aware of the drafting problem in the regulations and is moving to correct it. Unfortunately, this will take to about the end of the year. This leaves us back at the basic question of whether the asbestos fiber level in the dust generated by grinding is really distinguishable from the background level. A reliable method to distinguish and count asbestos fibers in the presence of other fibers is obviously needed. Actually, such a method will be important even when a cutoff limit is instituted since "operator judgment" is not the best way to distinguish nonasbestos fibers. Union Carbide has done considerable work in this area and has found several promising techniques that will be described in the November 1975 issue of the ASTM Journal of Testing and Evaluation. In addition, one of our scientists, Dr. Kuldip S. Chopra is chairman of a joint task group set up recently by Subgroups 11 and 15 of ASTM Committee E4. Their objective is to study methods to characterize and count submicron particles and develop an appropriate ASTM procedures manual. Dr. Don Bauman of Dow is a member of this task group. -3- It appears that procedures to count asbestos fibers in resin dust may be part of a broader analytical problem of common interest. If so, it may be useful to look at the problem cooperatively. Such cooperation could take the form of a discussion of possible analytical techniques, collection of air samples at an appropriate location, and analysis of selected samples by both laboratories. Hopefully, in the next few months, we can come up with a much better definition of the true asbestos fiber counts for this operation. If this is of interest to you, please let us know. While on the subject of toxicology, there is another important matter that needs to be covered. Very recently, we have become aware of the attached letter that appears to be in use by the Derakane technical service people. Unfortunately, it appears that more has been read into Mr. Myers talk than was intended. As you are well aware, at this time asbestos related diseases are a very emotional and controversial subject. The attached paper. Asbestos and Health, published by the Asbestos Information Association/North America, gives a good, up-to-date summary of the concensus position of a large proportion of the scientific community working in this area. There is substantial evidence of graded toxicological effects among different types of asbestos in the order of crocidolite, amosite, chrysotile, anthophyllite. The British Regulations recognize this in setting an allowable limit for crocidolite that is lower by a factor of 10 than that of the other types of asbestos and requiring special permission to handle this material. Chrysotile, like many industrial raw materials does present hazards at certain exposure levels and cannot be classified with the commonly recognized nuisance dusts. It is true that any distinction as to asbestos type has generally been ignored by the public press when discussing the hazards of asbestos. Of equal importance, however, has been the tendency to extrapolate the effects of -4- high exposure in industrial and quasi-industrial situations that usually occurred many years ago to predict hazards to the general public today. The combination of these two factors has been an important cause of the present emotional publicity that asbestos has received. In summary, we feel that the letter of Octover 16, 1974 is incorrect and misleading and its use should be discontinued. In its place, we will be glad to supply, for distribution to your customers, copies of the Asbestos and Health publication and/or the more complete brochure, "'Calidria' Asbestos RG-244, Health and OSHA Information, February 1, 1975," which you received in Washington. As in the past, we will aTso be happy to discuss the toxicology question with any of your customers which you wish to refer to us. Very truly yours, H. B. Rhodes Technology Manager HBR:cjb