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A method to empirically determine the gaseous emissions produced from a pyrotechnic flare composition through the combination of gas chromatography and mass spectrometry is described. In this approach, milligram quantities of a model yellow signal flare composition and its individual polymeric constituents were subjected to pyrolysis at conditions that were guided via thermal analysis. Many volatile organic compounds and polycyclic aromatic hydrocarbons were identified as emission products even though thermochemical calculations fail to anticipate such products. Thus, these data may complement characterization of emission products predicted in silico. Pyrolysis of this pyrotechnic composition also demonstrated unique products formed via donation of nitrogen to aromatic fragments originating from resinous portions of the formulation. These products included EPA priority pollutants that were not formed by decomposition from staple ingredients. This work demonstrates that a variety of EPA priority pollutants were formed during the simulated combustion of what would otherwise be considered an environmentally friendly pyrotechnic. These pollutants originated from commonly used polymeric ingredients indicating the true environmental impact of many polymer-based energetics may need to be revisited.

Smoke dyes are complex molecular systems that have the potential to form many molecular derivatives and fragments when deployed. The chemical analysis of smoke samples is challenging due to the adiabatic temperature of the pyrotechnic combustion and the molecular complexity of the physically dispersed reaction products. Presented here is the characterization of the reaction byproducts of a simulant Mk124 smoke signal on a multigram scale, which contain the dye disperse red 9 (1-(methylamino)anthraquinone), by ambient ionization mass spectrometry. Our previous work has examined the thermal decomposition of a simplified smoke system consisting of disperse red 9, potassium chlorate, and sucrose by anaerobic pyrolysis gas chromatography mass spectrometry performed at the laboratory milligram scale. The results from the lab scale test were compared with a fully functioned Mk124 in the field. To achieve this, Mk124 smokes were functioned in the presence of sampling swabs that collected byproduct residues from the smoke plume in the ambient environment. These swabs were then analyzed using ambient ionization mass spectrometry to identify the expended pyrotechnic residues, with particular interest in halogenated species. Previous work determined the toxicity of unforeseen byproducts identified on the laboratory scale, which were also detected in the field demonstrating the correlation of the laboratory testing to the fielded systems. By understanding the chemical composition of smokes and their reaction products, potential toxicity effects can be easily assessed, leading to safer formulations with improved performance. These results can help assess how smoke byproducts may impact Warfighter performance, personnel health, and the environment.