Document 3NvQbEdKLKwOwB5e03QzeRZd6

Inter-Company Correspondence COMPANY_______UjCiC.LOCATION------- Mellon Institute to location attimtion corx To Dr. T. W. 'Jale ;ew York Office Dr. S. R. Weidlein, Jr. Dr. A. W. Downes Y Dear Ton: You will recall that the current threshold Halt for vinyl chloride Is ?00 p.p.m., based largely on single guinea pig Inhalation studies by the Bureau of Mines about 22 years ago. An off-the-record phone call from V. K. Rowe gives ae incomplete data on their current repeated Inhalation study. Six months at 200, 200 and 100 p.p.a. has not found a no-effect level. Even 100 p.p.a. produced organ weight changes and grosa pathology, with aicropethology expected. Vinyl chloride monomer is more toxic has been believed. Rowe expects to get more Information before he decides whether or not this has any bearing on the safety of p*^vgine uses of vinyl resins. Dov has been disturbed at sales efforts saying chloroform is less toxic than carbon tet. They have completed six months Inhalation and find chloroform like carbon tet. This means its threshold limit win be lowered, as I have suggested for years. It was originally set by analogy with carbon tet, and never lowered when that for carbon tet was reduced. I suggest that these personal cocmunications not be quoted until Dow publishes. Henry F. Sayth, Jr amd THIN PUftM * IKTKH-4*4*lil'AP*Y ClMUKttfr"'N|IKTCK llMt.Y RECE.VEO 0V 2 7 1959 * ucc 004923