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

Abstract

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-exposure experiments, HC/Zn/TNT smoke induced concentration-dependent sensory irritation in mice and the occupational exposure limit (TLV) was estimated to be 4 mg/m3. In the repeated-exposure experiments, HC/Zn/TNT smoke induced sensory irritation at the beginning of the exposure. Pulmonary irritation tended to dominate when the exposures were repeated. With HC/Zn smoke we were unable to generate sufficient high exposure concentrations. In the repeated-exposure experiments, indications of sensory and pulmonary irritation were seen at concentrations used. No evidence of apoptotic cell death was found in caspase-3-like protease activity assay.

Toxicity of acute or repeated exposures to particles from pyrotechnic smokes in normal human bronchial epithelial (NHBE) cells 3D culture

“…24 h of exposure to RSS and HC-OS particles did not affect cell viability, which is in line with our previous study in SAEC(Martin de Lagarde et al, 2022). Other studies on total aerosol generated by red smokes and HC based smokes reported to cause decrease in cell viability of BEAS-2B and A549 cell lines, 24 h and 48 h after exposure(Hemmilä et al, 2010(Hemmilä et al, , 2013Hemmilä, Hihkiö, Kasanen, et al, 2007;van Hulst et al, 2017). Our tested concentrations appeared to be noncytotoxic.…”

Study on anti-infrared performance of organohalogen polymer smoke agent

“…HC (halogenated organic compound) smoke agent is a class of anti-visible-infrared composite smoke agents that contains organic halides and generates metal halides and carbon particles through combustion [1]. In the early stage, this type of smoke agent used hexachloroethane as the organic halide [2], so it was called HC smoking agent.…”