NTP TECHNICAL REPORT ON THE TOXICOLOGY AND CARCINOGENESIS STUDIES OF STODDARD SOLVENT IIC (CAS NO. 64742-88-7) IN F344/N RATS AND B6C3F1 MICE (INHALATION STUDIES) NATIONAL TOXICOLOGY PROGRAM P.O. Box 12233 Research Triangle Park, NC 27709 September 2004 NTP TR 519 NIH Publication No. 04-4453 U.S. DEPARTMENT OF HEALTH 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 and Prevention. 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 Use of Animals. The prechronic and chronic studies were conducted in compliance with Food and Drug Administration (FDA) Good Laboratory Practice Regulations, and all aspects of the chronic studies were subjected to 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. The interpretive conclusions presented in this Technical Report are based only on the results of these NTP studies. Extrapolation of these results to other species and quantitative risk analyses for humans require wider analyses beyond the purview of these studies. Selection per se is not an indicator of a chemical’s carcinogenic potential. Details about ongoing and completed NTP studies are available at the NTP’s World Wide Web site: http://ntp-server.niehs.nih.gov. Abstracts of all NTP Technical Reports and full versions of the most recent reports and other publications are available from the NIEHS’ Environmental Health Perspectives (EHP) http://ehp.niehs.nih.gov (866-541-3841 or 919-653-2590). In addition, printed copies of these reports are available from EHP as supplies last. A listing of all the NTP Technical Reports printed since 1982 appears on the inside back cover. NTP TECHNICAL REPORT ON THE TOXICOLOGY AND CARCINOGENESIS STUDIES OF STODDARD SOLVENT IIC (CAS NO. 64742-88-7) IN F344/N RATS AND B6C3F1 MICE (INHALATION STUDIES) NATIONAL TOXICOLOGY PROGRAM P.O. Box 12233 Research Triangle Park, NC 27709 September 2004 NTP TR 519 NIH Publication No. 04-4453 U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service National Institutes of Health 2 CONTRIBUTORS National Toxicology Program NTP Pathology Working Group Evaluated and interpreted results and reported findings Evaluated slides and prepared pathology report on rats (August 15 and October 8, 2002) R.S. Chhabra, Ph.D., Study Scientist A. Suttie, B.V.Sc., Ph.D., Chairperson D.E. Malarkey, D.V.M., Ph.D., Study Pathologist ILS, Inc. D.W. Bristol, Ph.D. K.J. Cimon, D.V.M., M.S. J.R. Bucher, Ph.D. Experimental Pathology Laboratories, Inc. J.R. Hailey, D.V.M. J.R. Hailey, D.V.M. J.K. Haseman, Ph.D. National Toxicology Program R.A. Herbert, D.V.M., Ph.D. M.A. Hanes, D.V.M. R.R. Maronpot, D.V.M. Duke University J.C. Peckham, D.V.M., M.S., Ph.D. R.A. Herbert, D.V.M., Ph.D. J.H. Roycroft, Ph.D. National Toxicology Program C.S. Smith, Ph.D. G.D. Hill, D.V.M., Ph.D. National Toxicology Program G.S. Travlos, D.V.M. A. Nyska, D.V.M. K.L. Witt, M.S., ILS, Inc. National Toxicology Program J.C. Peckham, D.V.M., M.S., Ph.D. Battelle Northwest Operations Experimental Pathology Laboratories, Inc. Conducted studies and evaluated pathology findings H.G. Wall, D.V.M., Ph.D. GlaxoSmithKline B.J. Chou, D.V.M., Ph.D., Principal Investigator (2-week G. Willson, B.V.M. & S. and 3-month studies) Experimental Pathology Laboratories, Inc. J.A. Dill, Ph.D., Principal Investigator (2-year studies) S.L. Grumbein, D.V.M., Ph.D. Evaluated slides and prepared pathology report on mice (June 13, 2002) B.K. Hayden R.A. Miller, D.V.M., Ph.D. A. Suttie, B.V.Sc., Ph.D., Chairperson R.A. Renne, D.V.M. ILS, Inc. R.B. Westerberg, Ph.D. N. Allison, D.V.M. Experimental Pathology Laboratories, Inc. Experimental Pathology Laboratories, Inc. S.V. Ching, D.V.M., Ph.D. SVC Associates, Inc. Provided pathology review K.J. Cimon, D.V.M., M.S. J.F. Hardisty, D.V.M., Principal Investigator Experimental Pathology Laboratories, Inc. N. Allison, D.V.M. J.R. Hailey, D.V.M. National Toxicology Program J.C. Peckham, D.V.M., M.S., Ph.D. M.A. Hanes, D.V.M. K.J. Cimon, D.V.M., M.S. Duke University G. Willson, B.V.M. & S. R.A. Herbert, D.V.M., Ph.D. National Toxicology Program Dynamac Corporation G.D. Hill, D.V.M., Ph.D. Prepared quality assurance audits National Toxicology Program A. Nyska, D.V.M. S. Brecher, Ph.D., Principal Investigator National Toxicology Program Stoddard Solvent IIC, NTP TR 519 3 Analytical Sciences, Inc. Biotechnical Services, Inc. Provided statistical analyses Prepared Technical Report P.W. Crockett, Ph.D., Principal Investigator S.R. Gunnels, M.A., Principal Investigator L.J. Betz, M.S. P.A. Gideon, B.A. K.P. McGowan, M.B.A. L.M. Harper, B.S. J.T. Scott, M.S. E.S. Paal, M.S.J. D.C. Serbus, Ph.D. R.A. Willis, B.A., B.S. 4 CONTENTS ABSTRACT . 7 EXPLANATION OF LEVELS OF EVIDENCE OF CARCINOGENIC ACTIVITY . 11 TECHNICAL REPORTS REVIEW SUBCOMMITTEE . 12 SUMMARY OF TECHNICAL REPORTS REVIEW SUBCOMMITTEE COMMENTS . 13 INTRODUCTION . 15 MATERIALS AND METHODS . 27 RESULTS . 39 DISCUSSION AND CONCLUSIONS . 63 REFERENCES . 67 APPENDIX A Summary of Lesions in Male Rats in the 2-Year Inhalation Study of Stoddard Solvent IIC . 77 APPENDIX B Summary of Lesions in Female Rats in the 2-Year Inhalation Study of Stoddard Solvent IIC . 117 APPENDIX C Summary of Lesions in Male Mice in the 2-Year Inhalation Study of Stoddard Solvent IIC . 151 APPENDIX D Summary of Lesions in Female Mice in the 2-Year Inhalation Study of Stoddard Solvent IIC . 189 APPENDIX E Genetic Toxicology . 229 APPENDIX F Clinical Pathology Results . 235 APPENDIX G Renal Toxicity Results . 243 APPENDIX H Organ Weights and Organ-Weight-to-Body-Weight Ratios . 245 APPENDIX I Reproductive Tissue Evaluations and Estrous Cycle Characterization . 251 APPENDIX J Chemical Characterization and Generation of Chamber Concentrations . 255 APPENDIX K Ingredients, Nutrient Composition, and Contaminant Levels in NTP-2000 Rat and Mouse Ration . 267 APPENDIX L Sentinel Animal Program . 271 Stoddard Solvent IIC, NTP TR 519 5 6 Stoddard Solvent IIC, NTP TR 519 SUMMARY Background White spirit (also called mineral spirit) is a complex mixture of solvents derived from oil. The most widely used white spirit in the paint industry is called Stoddard solvent, and it is also used as a dry cleaning agent and as a solvent for cleaning and degreasing. We studied Stoddard solvent IIC to determine if it caused cancer in rats or mice. Methods We exposed groups of 50 male and female rats and mice to air containing Stoddard solvent six hours per day for two years. Male rats were exposed to 138, 550, or 1,100 milligrams of Stoddard solvent per cubic meter of air; female rats and male and female mice were exposed to 550, 1,100, or 2,200 mg/m3. Similar groups of 50 animals were exposed to clean air in the same inhalation chambers 6 hours per day as the untreated control groups. Tissues from more than 40 sites were examined for every animal. Results There were more deaths in male and female rats exposed to the highest concentration of Stoddard solvent than in other animal groups. There were no differences in survival of mice exposed to the solvent. Male rats exposed to Stoddard solvent IIC had higher rates of tumors of the adrenal gland, and female mice exposed to Stoddard solvent IIC had slightly increased rates of liver adenomas. Conclusions We conclude that Stoddard solvent IIC caused cancer of the adrenal gland in male rats. An increase in liver tumors in female mice may have been related to exposure to Stoddard solvent IIC. There was no evidence that Stoddard solvent increased tumor rates in female rats or male mice. 7 ABSTRACT Stoddard Solvent IIC CAS No. 64742-88-7 Synonyms: Medium aliphatic solvent naphtha (petroleum); white spirit Stoddard solvent (white spirit/mineral spirit) is the most of 0, 138, 275, 550, 1,100, or 2,200 mg/m3, 6 hours per widely used solvent in the paint industry.