The distribution and excretion of hexabromobenzene after a single administration in rat.

The aim of this study was to investigate the disposition of [1-14C]-hexabromobenzene (HBB) in rats. The experiments were performed on 76 female Outbred IMP: Wist rats with body weight of 200 g +/- 20%. The compound was given orally in a single dose of 600 mg/kg and 4500 mg/kg. 14C radioactivity was traced in selected tissues, blood, urine and faeces, 0-72 hours following the administration. Maximum concentration of the 14C in blood was observed during the 2nd hour after the compound administration. The accretion of 14C in plasma proceeded with kinetic constant of 1.35/hour, whereas 14C-decline was biphasic. Half-lives for phase I and II were 1.2- and 440 hours, respectively. No substantial differences were noted in relation to the HBB dose. In tissues the highest radioactivity was observed in the fat tissue, adrenals and sciatic nerve. About 16 to 24% of the administered radioactivity was still retained in the rat body, 72 hours after administration of the compound. Faeces turned out to be the main route of excretion (about 75% of the given dose); only 1% was excreted in urine. Following on the literature data and our total balance of 14C elimination with faeces, we concluded, that almost 70% of 14C found in the faeces were composed of other metabolites than HBB and its lower-brominated derivatives. The above data indicate that HBB, especially in the case of chronic exposure, might accumulate in the body.