Atmospheric chemistry of halogenated OVOCs: a review of rate coefficients, dielectric strength, and environmental impact

Abstract

Anthropogenic activities have increased atmospheric emissions of halogenated compounds. Some of these are potent greenhouse gases; however, their current atmospheric concentrations are low. We assessed the potential risks and hazards of novel chemical substances before their introduction into the environment. Evaluation systems consider both the direct impacts of exposure to new compounds and the indirect effects associated with their deposition in soil and surface waters when evaluating atmospheric hazards and risks. Therefore, in this study, we reviewed previously published rate coefficient values for oxidants such as OH radicals and Cl atoms and the lifetime values of 94 oxygenated halogenated compounds, including halogenated esters, hydrofluoroalcohols, halogenated aldehydes, halogenated carboxylic acids, halogenated ketones, and diketones. We also reviewed previously calculated radiative efficiencies (REs) and global warming potentials (GWPs) for halogenated compounds over 20-, 100-, and 500-year time horizons. We also calculated instantaneous and lifetime-corrected REs and GWPs for 45 halogenated compounds that have not been previously mentioned in the literature. This study also includes global temperature change potential (GTP) values for more than 94 halogenated compounds over 20-, 50-, and 100-year time horizons. Among these, we report GTPs, including instantaneous and lifetime-corrected values, for 59 halogenated compounds for the first time in this study. We also calculated ozone-depleting potential (ODP) values for 14 chlorine-containing halogenated compounds. The calculated ODP values for these 14 halogenated compounds were low. In this study, we also considered the photochemical ozone creation potential (POCP) and acidification potential (AP) of halogenated oxygenated volatile organic compounds (XOVOCs). This review also provides a thorough investigation of the possible replacement of SF₆, a gas frequently used in electric insulation because of its high dielectric strength (DS). To identify an alternative, the DS values of all the compounds were determined and are provided in this review.