Contribution of Hydrofluorocarbons (HFCs) and Hydrofluoro-Olefins (HFOs) Atmospheric Breakdown Products to Acidification (“Acid Rain”) in the EU at Present and in the Future

Abstract

While hydrogen fluoride (HF) and hydrogen chloride (HCl) are not considered main air-pollutants in the EU, they have the potential to contribute to acidification. Hydrofluorocarbons (HFCs), hydrofluoro-olefins (HFOs) and hydrochlorofluoro-olefins (HCFOs) are used as refrigerants and for other applications. They break down in the atmosphere to produce HF and HCl (for HCFOs) and some of these fluorocarbons also break down to produce triflu-oroacetic acid (TFA). For the emissions of these fluorocarbons in the EU, a worst-case scenario estimates their theoretical potential contribution to acidi-fication and compares it to the acidification potential for the main air pollutants contributing to acidification, which are nitrous oxides (NO x), sulphur oxides (mainly SO 2), and ammonia (NH 3). The Acidification Potential from these fluorocarbons in 2016 is estimated at <0.5% of the total due to SO 2 , NO x , NH 3 , and it can be concluded that this is insignificant in the context of the main acidification air-pollutants. Assuming that the EU targets for emissions of SO 2 , NO x and NH 3 by 2030 are achieved, the Acidification Potential from HFCs, HFOs and HCFOs in 2030 is also estimated at <0.5% of the total due to SO 2 , NO x , NH 3 and will remain insignificant.