Document 62ZOLN8wx6zMjGD460kkJ4Z1

Sndutiual BIO-TEST JlaJMcrffrueA*, 9nc. 1810 FRONTAGE ROAD NORTHBROOK, ILLINOIS 60062 ADEA CODE 313 TELEPHONE 272-10)0 July 21, 1969 M 24 1353 Dr. Emmet Kelly Monsanto Company 800 N. Lindbergh Boulevard St. Louis, Missouri 63166 Dear Emmet: Our current price quotations for two-year feeding studies are as follows: Dog study at three dose levels and controls using 4/4 animals per group $36,000 Rat study at three dose levels and controls using 35/35 animals per group $25,000 In case a three-generation reproduction study should also be required, the cost would be $15,000. Since there appears to be some effect in the 90-day rat study at a dose level of 1,000 ppm, it is my opinion that the highest level for the twoyear study should be about 300 ppm with the lower levels at 100 and 30 ppm. If one is operating on a one-half log spread of dose levels, as we were in the 90-day study, it is common practice to back-off one level below an effect level in going from a 90-day to a two-year study. Another approach to defining dose levels would be to determine from extraction studies and application of proper safety margins the level which it would be necessary to clear and to scale up from that level at one-half log increments to define the two higher levels. It is common practice to require establishment of a 100 fold margin of safety based on two-year feeding studies. MONS 090338 Dr* Emmet Kelly -2- July 21, 1969 I do not feel that it would be advisable to use the animals on the Aroclor studies which are in progress as the controls for a new study. With best regards. Sincerely yours, OEFipsh Otis E. Fancher, Ph.D. Director HONS 090339