Document pBw1Gmez73BxY7VXxVqGKD3bE

v Monsanto Uontmte Ca<wiflv too N. St INII. Mmqiiii 83198 'kom: QU: 884-1000 July 18, 1975 Dr. J.C. Calandra Industrial BIO-TEST Laboratories 1310 Frontage Rd. Northbrook, 111. 60062 re: AROCLOR 2-year Rat Feeding Studies Dear Joe: The attached table summarizes a comparison of the 3 revised AROCLOR reports (12^2, 125^, 1250). In 2 instances, the previous conclusion of "slightly tumorigenic" was changed to "does not appear to be carcinogenic". The latter phrase is preferable. May we request that the AROCLOR 125^ report be amended to say "does net appear to be carcinogenic'. The number of hepatomas reported for AROCLORS 1260 and 12^2 have been interchanged. This appears to have arisen from con fusion regarding the numbering of the animals. The original reports show tumors in animals with numbers in the 100-300 range for AROCLOR 1260 and in the 500 to 800 range for AROCLOR 12^2. This leads me to conclude that the numbering scheme shown in the second set of reports is correct. With AROCLOR 125^ confusion is compounded. The original report showed tumors in animals with numbers in the units to teens, but the revised report shews animal numbers ranging from Uo to 1000. Can this be straightened out? I was unable to reconcile the differences in the animal numbers between the first supplemental report and the original reports, I had inquired as to the changes in the numbers. As I recall, I was told that the sections had been renumoered when the new slides were made and that a key relating to the sets of numbers STLCOPCB4030889 c Dr. J.C. Calandra July 18, 1975 Page - 2 - " would be supplied. This has not been done. It may not be necessary for AROCLORS 1260 and 12^2, but AROCLOR 125^ remains unresolved. Insofar as I can see, the remainder of the reports appear acceptable. Kindest personal regards. Sincerely, George J. Levlnskas, PhD Mgr., Environmental Assessment and Toxicology /bkp att. cc: Dr. George Roush, Jr., M.D. STLCOPCB4030890 F T%. I t 1 %)i Product Supplemental Report #1 (mailed) AROCLOR 1260 conclusion slightly tuaorigenic hepatomas range of P* 9 p. 10 P- 11 P 12 P. 8 P- test animal nos: . 600 to -800 1000 series 70 to 100 500 to 600 600 to 700 700 series Supplemental Report #2 (JCC delivered does not appear carcinogenic 7 100 to 300 8c 0 to 900 10 to 0 80 to 200 200 to 300 200 to 300 AR0CL0R 125^ conclusion hepatomas slightly tumorigenic slightly tumorigenic AR0CL0R 12^2 conclusion slightly tumorigenic does not appear carcinogenic hepatomas range of test animal nos. 3 as in report #2 as in report #1 for AROCLOR 1260 AROCLOR 1260 STLCOPCB4030891