Document Bv54Z3rdyNZa0pQOQpVoEe3OL

CC: D p. Roman - N3B Monsanto MO NSANTO INDUSTRIAL CH CM ICALS CO. 8 0 0 N. Undbargh BouUvtrd St. Louit, W ltio g fl 53166 Phon: (314) 6 9 4 -1 0 0 0 September 3, 1981 Dr. C. E. Mendoza Task Force for Reassessment of Chemical Safety Dept, of Health and Velfare Health Protection Branch Ottawa Ontario Canada K1A0L2 Dear Dr. Mendoza: Santophenfl>-l (Monsanto o-benzyl-p-chlorophenol) has been analyzed for 2,3,7,8-tetrachlorodibenzodioxin by an analytical method capable of detecting 0.5x10" * gm TCDD/gra Santophen-1; none has been detected. Approximately twenty lots of material produced In 1979 end 1980 were examined. The analytical method used liquid chromatographic separation with U.V.' detection, and was essentially similar to that described by Nestrick, e.al., (Anal. Chem., 1979, 5 1 , 2272). This method is capable of conclusively indicating the absence of 2,3,7,8i TCDD (above the detection limit) but it does not resolve this compound from seven isomers. No lot of Santophen-1 produced by Monsanto's current manufacturing process examined to date has shown evidence for the presence of 2,3,7,8-tetrachlorodibenzodioxin. Very truly yours, JDW/bh ccW-Mr. Keith MacHUl^.. 100 Argyle Ave. Ottawa, Ontario fmes D. Wilson Manager, Research & Development unit at M o fliiM o C o rn e o *