Document 853VRggw6w2oVaJ6RpXe6ywy5

The Saranac Laboratory F.r th. Study f Tub*rcul#i, Occupational Diaaaaa, and Induatriai Hygiana Founded by Eovau Livinustos Tatbtai' in 188S i Chuicm St., Sapanac u(, Ntw To** - V PLAINTIFFS EXHIBIT OH^.QQ p. o* a** msi July 27, 1956 Talaphanai Laboratory SIS Oirootor SH Mr. H.D. Burch Director of Personnel and Induatriai Relatione Owens-Corning Fibergla# Corporation 642 National Bank Gilding Toledo 1, Ohio PLAINTIFFS EXHIBIT b oom* Dear Mr. Burch: I believe I should point out to you that the articles which 1 recently on the biological action of glass fibers were based on experiment^ conducted at the Saranac laboratory during the period 1936 to 1967, all tiated by the late Dr. Leroy U. Gardner. Basically these experiments fell, into two categories, namely, injection studies and inhalation The injection studies were of an entirely artificial nature from*the' point of view of industrial medicine. They were conducted with a glass fiber J product which we had artificially reduced to a dust state. I can foresee no circumstances under which a commercial glass fiber product would, under normal industrial circumstances, he introduced into the human body in the form of this dust. Our interest in this product was purely academic. The inhalation phase of the research Work was conducted on a product fur nished by Owens Corning and, according to information furnished us, the glass fibers were reduced to particulate form for tne purposes of the experiment by a process of hammer milling at the Owens Corning plant prior to shipment to the Saranac Laooratory. It is also ay understanding that fibers such as these have no commercial use* The glass from which glass fibers are made, though it contains siUcfe, is not tcode because the silica is combined with the other ingredients o the glass. Glass is a silicate. In our various experiments in this laboratory silicates, with one exception, have been found to be relatively harmless com pared to minerals containing free silica. The exceptional fora is asbestos* Our interest, in the glass fiber arose out of the fact that it is fibrous aS we had previously shown in this laboratory that asbestos dust is harmful only>' ^-< if inhaled In a fibrous state. The results of the experiments with glass fibers are of interest In that they showed that length of fiber is;notvthm^^^%': only factor concerned in the causation of lung fibrosis, inasmuch as'asbei does cause fibrosis and glass fibers cause no such fibrosis. -:CV`rS>4- 'VlvvTV* * -- . : ir.*&*&&.* ' v-aradr. v~'-. The objectives of The Sarente Leboretory. a non-pfojit *t^maiMtincorp*Ttuf^m3ii At^4ueatum.L4i^ ` XcmwcR. C&thaian, Hr. M.D. Burch -2- July 27, 1956 I should point out, too, that our experiences with dusts of a great variety of kinds have emphasised the fact that only dust particles smaller than 10 microns in diameter can cause lung damage whereas particles greater than 200 microns cannot even be retained in the lungs. To the beet of my knowledge the glass fibers which are currently on the market are produced in a fllammted form exceeding a 200-eicroo length many fold. As you know, a fiber 200 microns long is so small that it is barely visible. Tours sincersly, CWKS:mem C.V.H. Schepere, K.D., D.Sc. Director