Atmospheric Chemistry of Halogenated OVOCs: A Review of Rate Coefficients, Dielectric Strength, and Environmental Impact.

Abstract

Anthropogenic activities have increased the atmospheric emissions of halogenated compounds. Some of these are potent greenhouse gases, but their present-day 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 of their deposition in soil and surface water while 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 their lifetime values for 94 oxygenated halogenated compounds, including halogenated esters (FESs), hydrofluoroalcohols (HFAs), halogenated aldehydes (FAs), halogenated carboxylic acids (FCAs), halogenated ketones (FKs), and diketones (FDKs). We reviewed previously calculated radiative efficiencies (REs) and global warming potentials (GWPs) of halogenated compounds over 20, 100, and 500-year time horizons, which are summarised in this study. We also calculated the instantaneous and lifetime-corrected REs and GWPs of 45 halogenated compounds that have not been mentioned previously in the literature. This study also includes global temperature change potential (GTP) values for over 94 halogenated compounds across 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. We also calculated the ozone-depleting potential (ODP) values of chlorine-containing 14 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. This review also provides a thorough investigation of the possible replacement of SF6, a gas frequently used in electric insulation owing to its high dielectric strength (DS). To find an alternative replacement, the DS values of all compounds were determined and are provided in this review.