Document YD7JoDOVZ7DwJ9bpBmyOD1X6N

WM****'*-- WPHWW.B l-i,,--lf: i.-: aiatti Mil PLAINTIFF'S EXHIBIT DUP-686 Plastics Department Commercial Raima Division Experimental Station RECEIVED -v i966 HASKELL LABORATORY C 'GO dT/. cc: H. L. Catas, Jr. J. W. Clayton, Jr N.R. C. Doban B. Bpstaln E. H. Prlca E. H. Tan Eyck File: 33A 323 Haskell D Bldg. 323 323 WWL November 7, 1966 ye-. J. F. MOROAN finployee Ralatlons Department, Haikall Lab FROM: R. A. DARBY c TOXICITY OF ASBESTOS Wa eartalnly appraclatad your visit on November 3 to discuss health problams assoclatad with tha usa of asbastos. In accord with your recommendations, wa ara proceeding as follows: 1. Work with any typa asbastos has baan haltad until wa hava obtalnad approvad faca masks (racosnandad by tha Buraau of Minas) for flltarlnc asbastos dust. 2. Haskall Laboratory will ba lnvitad to obsarva our semiworks oparatlons wharaby asbastos will ba extrusion compounded At tha moment wa do not hava a firm data for this, partly bacauaa tha approvad masks ara not in hand. 3. In vlaw of your cosssants, wa will not purehasa or work with tha crooodollta form of asbastos pendlnc furthar classi fication of this matarlal. As I understand It, this form of asbastos contains maasurabla amounts of benzpyrene, a carcinogen, and tha lncidanca of cancar In South African alnar* has baan ralatad to axposura to crooodollta. Tha major fora of asbastos, t chrysotlla, apparently la much safer than croeodollta In this respect. Wa would appreciate your opinion of tha hazards of anthophylllte asbastos, which Is supplied by tha Blue Rock Mining Corporation. U. Haskell Laboratory will keep us Informed of future developments In thalr study of tha toxicology of asbestos. For example, tha Investigation of an Instrument(lmplnger) to measure dust concentration may ba a significant benefit to us and other groups working with such materials as asbastos or glass. I gatherad from your cosaents that dust levels below 5 MM partlcles/ft* DUF 09006S3 I DU 022080 uiaamJaagBimlla; nffiNH J. P. Morgan -2- November 7, 1966 are generally safe for chrysotlle asbestos, while concentrations of glass dust lass than 20 MM partleles/ft* are not harmful. (A reference value of 0.5 MM partieles/ft* for an office or similar * room may be helpful in appreciating the levels mentioned above.) In recalling our discussion, believe you mentioned that asbestosls, which is the formation of nodules around asbestos fibers accumulated in the lung, results frosi continuous exposure to asbestos dust for long periods of time, and is similar to sill* . coals. Asbestosls can lead to cancer in the lower lobes of the lung. Mesothelioma is the formation of malignant tumors in the layer of tissue called the mesothella, and usually occurs in the plural cavity, although tumors have been known to develop in the same stratum of tissue elsewhere in the body. Your guidance in the proper handling of asbestos, glass and relatad fillers for plastics will be greatly appreciated. This area of research haa considerable business potential and while ws do not want to inhibit ourselvea unnecessarily, we want to make sure that our operations are consistent with the latest medical knowledge. s do DUP 0900664