Document ev9QZda6OXLbwqaRwk7pKp4em

CC: D. P. Roman - N3B Monsanto MONSANTO INDUSTW AL CHEM ICALS CO. 8 0 0 N. Lindbargh Boulevard St. Louis, M issouri 63166 Phon: (314) 6 9 4 -1 0 0 0 September 3, 1981 Or. C. E. Mendoza Task Force for Reassessment of Chemical Safety Dept, of Health and Welfare Health Protection Branch Ottawa, Ontario Canada K1A0L2 Dear Dr. Mendoza: Santophen-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/gm Santophen-1; none has been detected. Approximately twenty lots of material produced In 1979 and 1980 were examined. The analytical method used liquid chromatographic separation with U .V . detection, and was essentially similar to that described by Nestrlck, et.al., (Anal. Chem., 1979, 51, 2272). This method is capable of conclusively indicating the absence of 2,3,7,8* 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-tetrachlorodlbenzodloxln. Very truly yours. JDW/bh c c **-M r. K eith MacMlUaxx, 100 Argyle Ave. Ottawa, Ontario s D. Wilson lanager, Research & Development * unit of M o n i i n i s Com pany