Document wg8NEJGggQw7pwKQyONjko62B

Sa&uAtAjud 11 0 . T E s T 1810 PRONTAGS ROAD NORTHBROOK.ILLINOIS 60062 Ska. REPORT TO ' MONSANTO COMPANY TWO - YEAR CHRONIC ORAL TOXICITY STUDY WITH ' AROCLOR 1260 IN ALBINO RATS HISTOPATHOLOGICAL EVALUATION OF ADDITIONAL LIVER SECTIONS MARCH 24, 1975 IBT NO. 641 - 06672 TH OSH 036626 HARTOLDMONO015610 9ndjuL&AMit BIO - TEST Jh/w^yueS, Snc. 1810 fHONTAGS OAO NORTHJHOOK, ILLINOIS 60062 March 24, 1975 George J. Levinskas, Ph.D. Monsanto Company 300 N. Lindbergh 31vd. St. Louis, Missouri 63 166 Dear Dr. Levdnskas: He; I3T Ns. 641 -06672 - Histspatholog:cal Evaluation of Additional Liver Sections From Rats of a Two - Year Chronic Oral Tonic'-' S cudv of A roc lor 1260,____________ We are submitting herewith our laboratory report dated March 2 4, 1975; prepared is connection, with the above study. Very truly yours, c^>vr/._<--, J. C. Calandra Pre sideat 0SM Q3bo2 7 HARTOLDMON0015611 ZmUiW B I O - T E S T 2a**~dvdU. 2*0. REPORT TO MONSANTO COMPANY TWO - YEAR CHRONIC ORAL TOXICITY STUDY WITH AROCLOR 1260 IN ALBINO RATS HISTOPATHOLCGICAL EVALUATION OF ADDITIONAL LIVER SECTIONS MARCH 24, 1975 13T NO. 641 - 06672 I. Introduction _ At the request of Dr. Levinslca* of the Monsanto Company, additional sections of liver from a two - year chronic oral toxicity study of Aroclor 1260 in rats (IB7 No. 622 -07298) were processed Into H it E stained sections and evaluated by light microscopy. The following report presents the results of this study. OSW 036623 HARTOLDMON0015612 sJudtJai a i O - T S T Jcdmatmdiii. 3ms. II. Surrx-.ary In most instances, the treatment-re la ted histopathological findings in the liver from this re -evaluation did not differ significantly from that previously reported in our original report dated November 12, 1971. However, there were three benign liver tumors detected among three of the animals at the highest treatment level (100 ppm) of the 24-Month Sacrifice which were cot previously reported. The other treatment - re la ted lesions reported are regarded as de generative or hyperplastic in nature and they are morphologic man if e stations of an adaptive response of the liver associated with bio transformation of the test material. In general, the latter findings were confined primarily to test animals of the final sacrifice and they were dose - related in incidence and severity. In conclusion, Aroclor 1260 appears to be slightly tumorigenic at levels of 100 ppm when fed continously In the diet for two years. Respectfully submitted, INDUSTRIAL BIO-TEST LABORATORIES, INC. Report Prepared and Reviewed by: Section Head, Pathology Report Approved by: Manager, Toxicology OSH Q3oo29 HARTOLDMON0015613