Document NNkDddqyXv6gR9LR4wJqn7oM8

Monsanto U9MIM C"Y 00 N LiMM'g* loul*ir St M.iu*n 3103 Pasas: 314: 4.I000 July 18, 1975 Dr. J.C. Calandra Industrial BIO-TEST Laboratories 1310 Frontage Rd. Northbrook, 111. 60062 Dear Joe: re: AROCLOR 2-year Rat Feeding Studies 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 not 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 1242. This leads me to conclude that the numbering scheme shown in the second set of reports is correct. With AROCLOR 1254 confusion is compounded. The original report showed tumors in animals with numbers in the units to teens, but the revised report shows animal noabers ranging from 4o 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 V.noiWl receives JUL 2 1 STLCOPCB4028036  Dr. J.C. C&landra July 18, 1975 Page -2-7 c - would be supplied. This has not been done. It may not be necessary for APOCLORS 1260 and 1242, but AROCLOR 1254 remains unresolved. Insofar as I can see, the remainder of the reports appear acceptable. Kindest personal regards, Sincerely, George J. Levinskas, PhD Mgr., Environmental Assessment and Toxicology /bkp att. cc: Dr. George Roush, Jr., M.D. MM?.'/2 ioo; STLCOPCB4028037 ff t Product Supplemental Report #1 (mailed) AROCLOR 1260 conclusion slightly tumorigenic hepatomas 3 range of P. 9 p. 10 p. 11 p. 12 P- 13 p. 14 test animal nos: 600 to 800 1000 series 70 to 100 500 to 600 600 to 700 700 series Supplemental Report $2 (JCC deltve^-ori does not appear carcinogenic 7 100 to 300 800 to <500 10 to 4o 80 to 200 200 to 300 200 to 300 AROCLOR 1254 conclusion hepatomas slightly tumorigenic 6 slightly tumorigenic 6 AROCLOR 1242 conclusion slightly tumorigenic does not appear carcinogenic hepatomas 7 3 range of test animal nos. as in report #2 as in report #1 for AROCLOR 1260 AROCLOR 1260 Foni 273 1007 3 3 STLCOPCB4028038