In Vivo and In Vitro Evaluation of the Acute Toxicity, the Genotoxicity, and the Irritation Potency of Two Hexachloroethane-based Pyrotechnic Smokes

The two hexachloroethane (HC)-based smoke formulations studied consisted of HC/Zn/2,4,6-trinitrotoluene (TNT) and HC/Zn. In the in vitro tests, human bronchial epithelial cells were exposed to the smokes at various concentrations. The responses studied were acute toxicity (viability of cells, trypan blue exclusion method) and genotoxicity (DNA single-strand breaks, COMET assay). The tests were conducted in a laboratory-scale chamber (V = 150 L) and in a container (V = 55 m3). Both smoke formulations appeared to be acutely toxic and genotoxic. For the 0.5- and 1-g burning experiments the responses were more pronounced with HC/Zn/TNT than with HC/Zn smoke. To study the irritation potency of the smokes, the mouse bioassay according to ASTM E 981-84 was applied. The respiratory parameters measured were tidal volume (VT), airflow during expiration at 0.5 VT (VD), time of pause after expiration (TP), time of breaking after inspiration (TB), and the respiratory frequency (BPM; breaths per minute). In the single-...