Author information Indiana University School of Medicine, Division of Toxicology, Department of Pharmacology and Toxicology, 635 Barnhill Drive, MS 1021, Indianapolis, Indiana 46202, USA. Abstract Indium phosphide (IP), widely used in the microelectronics industry, was tested for potential carcinogenicity. Sixty male and 60 female Fischer 344 rats were exposed by aerosol for 6 h/day, 5 days/week, for 21 weeks (0.1 or 0.3 mg/m(3); stop exposure groups) or 105 weeks (0 or 0.03