CARCINOGENIC ACTIVITY OF THE FLAME-RETARDANT, 2,2-BIS(BROMOMETHYL)-1,3-PROPANEDIOL IN RODENTS, AND COMPARISON WITH THE CARCINOGENICITY OF OTHER NTP BROMINATED CHEMICALS

Several brominated chemicals have been shown to be multisite-multispec ies carcinogens in laboratory animals, and in this paper we report tha t the flame retardant, 2,2-bis(bromomethyl)-1,3-propanediol (BMP) is a lso a multisite carcinogen in both sexes of Fischer 344 rats and B6C3F (1) mice. BMP was administered continuously in the diet for up to 2 yr to rats at doses of 0, 2,500, 5,000, or 10,000 ppm and to mice at dos es of 0, 312, 625, or 1,250 ppm. Interim groups of rats were examined at 15 mo. An additional recovery group of male rats received the chemi cal for 3 mo at 20,000 ppm in the feed, and then the control diet for the remainder of the study. Chemical exposure caused neoplasms of the skin, subcutaneous tissue, mammary gland, Zymbal's gland, oral cavity, esophagus, forestomach, small intestine, large intestine, mesothelium , kidney, urinary bladder, lung, thyroid gland, seminal vesicle, hemat opoietic system, and pancreas in the male rat; mammary gland, oral cav ity, esophagus, and thyroid gland in the female rat; lung, kidney, and Harderian gland in male mice; and subcutaneous tissue, lung, and Hard erian gland in the female mouse. The recovery group of male rats prese nted with the same spectrum of treatment-related neoplasms as in the c ore study. In this recovery group, BMP (at 20,000 ppm) caused irrevers ible effects at numerous sites after 90 days of exposure that was not detectable by histologic examination, but without further exposure res ulted in carcinogenic responses at 2 yr. BMP is mutagenic in the salmo nella test, but it was not determined if the BMP-induced effects that eventually lead to development of neoplasms at multiple sites are the same in both species and in all organ systems affected.