Document Rppvx9XBGdQw5OJ0NeYj5D4jk

'Pk is p Monsanto bcc : P. J. A m a l i B3NJ r- . S. Metcalf N3A G. D. Stevens 1070 M O N SA N T O IN D U ST R IA L C H EM IC A LS CO. 800 N. Lindbtrgh Boulevard S t . L o u is . M is s o u r i 63166 Ph o n: G I4 ) 694-1000 March 17, 1981 Mr. Conrad Harwell Diamond Shamrock Tuscaloosa Works P.0. Box H Tuscaloosa, AL 35404 Dear Mr. Harwell: As part of Monsanto's continuing dedication to know as much as possible about our products, we have recently upgraded our abilities to analyze for trace contaminants. Applying these to our 93% 2,4-dichlorophenol produced in 1980 disclosed that one lot of thirteen examined contained between 5 and 15 x 10"^ gm/gm (ppb) of tetrachlorodibenzodioxins (TCDD). Several of the other lots may have contained TCDD's below the 5 ppb analysis limit. The predominant isomer appeared to be that expected from self-reaction of 2,4,6-trichlorophenol; i.e., 1,3,6,8-tetrachlorodibenzodioxin. Monsanto believes that 93% DCP with these levels of TCDD impurities does not pose a hazard to your workers or the public any greater than that posed by DCP itself. We are informing you of these findings in consistency with Monsanto's policy of sharing with customers information about Monsanto's products that may be of utility in the conduct of your business. Very truly yours, cc: Mr. Jerry R. Lucietta Registration & Regulation Diamond Shamrock 1100 Superior Avenue Cleveland, OH 44114 Manager, R&D, Product Acceptability and Environmental Affairs