Document 10RV0zpOYXoKX8rX274mrqzVE

Interoffice Communication to Distribution From J J . Hal 1 Date October 21, 1980 Subject CARCINOGENESIS BIOASSAY OF DOP conoco /id1 The National Cancer Institute has released a long-awaited prepublication draft of their now famous carcinogenesis bioassay on dl(2-ethylhexyl) phthalate. This draft has been made available for the purpose of scientific peer-review. The final report is scheduled to be published in three to six months. Attached is a copy of the summary. I will keep you advised as to the significance of jKis study as information develops. If you have questions please call. Distribution Houston: J.J. Doyle N.C. Frost D.A. Kuhn B.E.A. Larsen R.E. Lehmkuhl V.A. Moore M.S. Reynolds C.L. Sanderson Ponca City: W.D. Broddle R.L. Huddleston F. Kennedy A.J. Lundeen R.M. Owens H. Washecheck Aberdeen: C.L. Miller A.H. Sather UEU-243S12 DRAFT CARCINOGENESIS 8IQASSAY / Of DI(2-ETHYLHEXYL]PHTHALATE (CAS No. 117-31-7) 15 October 1980 NTP-80-37 OHHS Publication Number (NIH) 31-1773 Carcinogenesis Testing Program NATIONAL TOXICOLOGY PROGRAM P. 0. Box 12233 Research Triangle Park North Carolina 27709 NOTICE This Is not a final report. Until this DRAFT is reviewed and approved by the Technical Reports Review Subcommittee of the NTP Board of Scientific Counselors, this DRAFT does not represent the official position of the National Toxicology Program. Public Health Service DeparGnent of Health and Human Services VBJ-243813 3I0ASSA? 0? DX (2-XTHTL2EXnJ PETHALATX FOR P0SSI3L2 CAHCIROCdlCIT? 4 Carcinogenesis Testing Program Rational Cancer Inscicuca/Rational Toxicology Program SORSSORD This report presents the results of the bioassay of diCX-ethylhexyl)- phthalata conducted for she Carcinogenesis Testing Program, Rational Cancer Institute (NCI)/Rational Toxicology Program CRT?)* This is one of a series of experiments designed to determine whether selected chesieels hare the capacity to produce cancer in animals, A negative result, in which the test animals do soe hare a greater incidence of cancer than control animals, does not necessarily maan that a cast ehsmical is not a carcinogen, inasmuch as tha experiments are conducted under a limited sac of circuastancas. k posi tive result demonstrates that a test chemical is carcinogenic for animals under the conditions of the test and indicates that exposure to the chemical is a potential risk Co man# Tha actual determination of tha risk to from chemicals found to be eareinogenic in animals requires a wider analysis which extends beyond the purview of this study. STASIAS? A bioassay of di(2~chylhexyl)phchalate, the most coasaonly used plasti ciser for polyvinylchloride polymers, for possible carcinogenicity was con ducted by feeding diets containing 5,000 or 12,000 ppm of the test chemical to groups of 50 aale or female F34A rats and 3,000 or 6,000 ppm to groups of 50 male or female 36C3F1 sice for 103 weeks. Matched controls chnsiseed of 50 vatreated rats and 50 untreated sice of either sex. Mean body weights of dosed rats and sice were lover chan chose of the corresponding controls throughout the study. Hepatocellular carcinomas or neoplastic nodules in high--dose rats of either sex and in low-dose females and hapacoeellular carcinomas or adenomas in lav-- and high-dose mice of either sex occurred at incidences significantly higher than chose in the matched controls. Degeneration of the seminiferous tubules and atrophy of tha testes and hypertropy of cells in the anterior pituitary were also found at increased incidences in high-dose aale raes. Cndar the conditions of this bioassay, di^-etthylhexyDphthalate was carcinogenic for 7344 rats and 36C3FI mice of either sex, causing increased incidences of hepatocellular carcinomas or neoplaseie nodules in rats and hepatocellular carcinomas or adencmas in mice. MEV-2438H James J. Hall To /4^h. PI*# Cconoco) Date Employee General Medical History and Industrial History - General Medical History enables the examining physician to determine the employee's present state of health* as well as to discover any past health problems, - Industrial History (See page Three) I i TtlYkOli) HCOtCATIOH VUAMlHS `Vcu^e'!^^ MT,ENT sr*m TMT E ' A tttOO) FKCSLUR6 CHECK A CHEil X-RAY