The in-life portion of a two generation reproduction inhalation study using Normal Propyl Bromide in Sprague Dawley rats, sponsored by the Brominated Solvents Committee, was initiated at Huntingdon Life Sciences laboratories, East Millstone, New Jersey, in April, 1999. The study was terminated July 5, 1999, when the first generation control animal group (which was not exposed to the test chemical) failed to produce the 20 litters of offspring required for a valid study the the methodology used. Reasons for the low fertility in this group are not known. Similar numbers of litters were seen in all but the highest exposure group, which failed to produce offspring. Other effects seen in the treatment groups were decreased weight gains in the two highest groups of females over the majority of the study.