NATIONAL TOXICOLOGY PROGRAM Technical Report Series No. 432 TOXICOLOGY AND CARCINOGENESIS STUDIES OF BARIUM CHLORIDE DIHYDRATE (CAS NO. 10326-27-9) IN F344/N RATS AND B6C3Fl MICE (DRINKING WATER STUDIES) U.S. DEPARTMENT OF HEALTE AND HUMAN SERVICES Public Health Service National Institutes of Health FOREWORD The National Toxicology Program (NTP) is made up of four charter agencies of the U.S. Department of Health and Human Services (DHHS): the National Cancer Institute (NCI), National Institutes of Health; the National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health; the National Center for Toxicological Research (NCTR), Food and Drug Administration; and the National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control. In July 1981, the Carcinogenesis Bioassay Testing Program, NCI, was transferred to the NIEHS. The NTP coordinates the relevant programs, staff, and resources from these Public Health Service agencies relating to basic and applied research and to biological assay development and validation. The NTP develops, evaluates, and disseminates scientific information about potentially toxic and hazardous chemicals. This knowledge is used for protecting the health of the American people and for the primary prevention of disease. The studies described in this Technical Report were performed under the direction of the NIEHS and were conducted in compliance with NTP laboratory health and safety requirements and must meet or exceed all applicable federal, state, and local health and safety regulations. Animal care and use were in accordance with the Public Health Service Policy on Humane Care and Useof Animals. The prechronic and chronic studies were conducted in compliancewith Food and Drug Administration(FDA) Good Laboratory Practice Regulations, and all aspects of the chronic studies were subjectedto retrospective quality assurance audits before being presented for public review. These studies are designed and conducted to characterize and evaluate the toxicologic potential, including carcinogenic activity, of selected chemicals in laboratory animals (usually two species, rats and mice). Chemicals selected for NTP toxicology and carcinogenesis studies are chosen primarily on the bases of human exposure, level of production, and chemical structure. Selection per se is not an indicator of a chemical's carcinogenic potential. These NTP Technical Reports areavailable for sale from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161 (703-487-4650). Single copies of this Technical Report are available without charge while supplies last from the NTP Central Data Management, NIEHS, P.O. Box 12233, MD AO-01, Research Triangle Park, NC 27709 (919-541-1371). NTP TECHNICAL REPORT ON THE TOXICOLOGY AND CARCINOGENESIS STUDIES OF BARIUM CHLORIDE DIHYDRATE (CASNO. 10326-27-9) IN F344/N RATS AND B6C3F, MICE (DRINKING WATER STUDIES) NATIONAL TOXICOLOGY PROGRAM P.O. Box 12233 Research Triangle Park, NC 27709 January 1994 NTP TR 432 NIH Publication No. 94-3163 U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service National Institutes of Health 2 Barium Chloride Dihydrate, NTP TR 432 CONTRIBUTORS National Toxicology Program NTP Pathology Working Group EvaIuared and mterpmed results and report @&gs Evaluated slides, prepared pa&bgv report on rats (19 June 1991) KM. Abdo, Ph.D. P.K. Hildebrandt, D.V.M., Chair C.J. Alden, Ph.D. PATHCO, Inc. G.A. Boorman, D.V.M., Ph.D. J.R. Hailey, D.V.M. D.A. Bridge, B.S. National Toxicology Program J.R. Bucher, Ph.D. B.F. Hamilton, D.V.M., Ph.D. S.L. Eustis, D.V.M., Ph.D. Experimental Pathology Laboratories, Inc. T.J. Goehl, Ph.D. M. Heinrichs, D.M.V. (observer) J.R. Hailey, D.V.M. Boehringer lngelheim KG J.K. Haseman, Ph.D. M.P. Jokinen, D.V.M. G.N. Rao, D.V.M., PbD. National Toxicology Program J.H. Roycroft, Ph.D. M.M. McDonald, D.V.M., Ph.D. B.A. Schwetz, D.V.M., Ph.D. National Toxicology Program C.C. Shackelford, D.V.M., MS., Ph.D. C.C. Shackelford, D.V.M., MS., Ph.D. National Toxicology Program D.B. Walters, Ph.D. KL.Witt, M.S., Oak Ridge Associated Universities Evaluated slides, prepared pathology report on mice (2 August 1991) SRI International W. Hall, V.M.D., Ph.D., Chair Conducted IS-& and 13-week smdies, evaluated Pathology Associates, Inc. pathology findings J.M. Cullen, V.M.D., Ph.D. North Carolina State University W.E. Davis, PrincipalInvestigator S.L. Eustis, D.V.M., Ph.D. E.F. Meierhenry National Toxicology Program J.R. Hailey, D.V.M. EG&G Mason Research Institute National Toxicology Program Conducted 2-year smdiq evaluated pathology findng B.F. Hamilton, D.V.M., Ph.D. Experimental Pathology Laboratories, Inc. AG. Braun, Sc.D., PrincipalInvestigator R.A. Herbert, D.V.M., Ph.D. (observer) L.E. Sendelbach, Ph.D. National Toxicology Program F. Voelker, D.V.M. M.M. McDonald, D.V.M., Ph.D. National Toxicology Program Experimental Pathology Laboratories, Inc S. Qureshi, B.V.Sc., Ph.D. Sandoz, Ltd. Provided pathology quality assurance J.F. Hardisty, D.V.M., PrincipalInvestigator Biotechnical Services, Inc. B.F. Hamilton, D.V.M., Ph.D. hepared Technical Report D.D. Lambright, Ph.D., PrincipalInvestigator Dynamac Corporation J.R. Beverly, B.A. Prepared quality assurance audits P. Chaffin, MS. G.F. Corley, D.V.M. S. Brecher, Ph.D., PrincipalInvestigator P.A. Fink Martin, D.A. AB. James-Stewart, B.S. E.S. Rathman, M.S. 3 CONTENTS ABSTRACT ................................................................... 5 EXPLANATION OF LEVELS OF EVIDENCE OF CARCINOGENIC ACTIVITY ............... 9 TECHNICAL REPORTS REVIEW SUBCOMMITTEE ................................... 10 SUMMARY OF TECHNICAL REPORTS REVIEW SUBCOMMITTEE COMMENTS ........... 11 INTRODUCTION .............................................................. 13 MATERIALSANDMETHODS .................................................... 19 RESULTS .................................................................... 29 DISCUSSION AND CONCLUSIONS ................................................ 51 REFERENCES ................................................................ 55 APPENDIXA Summary of Lesions in Male Rats in the 2-Year Drinking Water Study of Barium Chloride Dihydrate ......................................... 61 APPENDIX B Summary of Lesions in Female Rats in the 2-Year Drinking Water Study of Barium Chloride Dihydrate ......................................... 103 APPENDIX C Summary of Lesionsin Male Mice in the 2-Year Drinking Water Study of Barium Chloride Dihydrate ......................................... 145 APPENDIX D Summary of LesionsinFemaleMicein the 2-Year Drinking Water Study of Barium Chloride Dihydrate ......................................... 179 APPENDIXE Genetic Toxicology ................................................. 217 APPENDIXF Organ Weights and Organ-Weight-to-Bodyweight Ratios .................... 231 APPENDIXG Neurobehavioral and Cardiovascular Analyses ............................ 243 APPENDIX H Hematology and Clinical Chemistry Results .............................. 255 APPENDIXI Plasma Barium Levels and BoneAnalyses ............................... 265 APPENDIXJ Chemical Characterization and Dose Formulation Studies ................... 269 APPENDIXK Water and Compound Consumption .................................... 277 APPENDIX L Ingredients. Nutrient Composition. andContaminant Levels in NIH-07 Rat and Mouse Ration ...................................... 283 APPENDIX M Sentinel Animal Program ............................................ 289 ABSTRACT BARIUM CHLORIDE DIHYDRATE CAS NO.10326-27-9 Chemical Formula: BaCI,.2H20 MolecularWeight: 244.28 Barium chloride dihydrate, a whitecrystalline granule SDAYSTUDY IN MICE or powder, is used in pigments, aluminum refining, Groups of five males and five females received leathertanningand coloring, the manufacture of barium chloride dihydrate in the drinking water at magnesium metal, ceramics, glass, andpaperpro- concentrations of 0,40,80,173,346, or 692 ppm for ducts, as a pesticide, and in medicine, as a cardiac 15days, corresponding to average daily doses of 5,10, stimulant. Toxicology and carcinogenicity studies 20,40, or 70mg bariumkg body weight to males and wereconducted by administeringbariumchloride 5, 10, 15, 40, or 85 mg bariumkg body weight to dihydrate (99% pure)indrinkingwater to M44/N females. No chemical-relateddeaths, differences in ratsand B6C3Fl micefor 15 days, 13 weeks, and mean body' weights of inwaterconsumption, or 2 years. Genetic toxicology studies were conductedin clinical findings of toxicity were observed in mice. Salmonella typhimurium, culturedChinesehamster The relative liver weight of males receiving 692 ppm ovary cells, and mouse lymphoma cells. was significantly greater thanthat of the controls. The absolute andrelative liver weights of females that received 692 ppm weresignificantly greater than 15-DAY STUDY IN RATS those of the controls. No histopathologic evidence of Groups of five males and five females received toxicity was observed in mice. barium chloride dihydrate in the drinking water at concentrations of 0, 125, 250, 500, l,OOO, or 2,OOO ppm for 15 days, corresponding to average daily ISWEEK STUDY IN RATS doses of 10,15, 35, 60, or 110 mg bariumkg body Groups of 10 males and 10 females received barium weight to males and females. No chemical-related chloride dihydrate in the drinking water at concen- deaths, differences in final mean body weights, or trations of 0, 125,500,l,OOO, 2,OOO, or 4,OOO