Environmental Benefits of Substituting Coatings from Solvent-Borne to Water-Borne Coatings Revealed by Total OH Reactivity Measurements

This is the authors' abstract. We don't add key points for this paper.

As an important category of volatile chemical products, coatings contribute significantly to the emissions of reactive organic compounds. While environmental policies have accelerated the replacement of solvent-borne coatings with water-borne alternatives, the secondary formation potential induced by this substitution remains poorly constrained. In this study, we investigate the total reactive organic compound emissions of solvent- and water-borne coatings in terms of total OH reactivity (OHR). The emission factors of the OHR for solvent-borne coatings are 128 times higher than those for water-borne coatings. The huge difference dominantly stems from solvent contents by a factor of 80, with the remaining difference attributed to the average OH reactivity for unit mass of emissions (a factor of 60%). We show that substitutions of solvent-borne coatings with water-borne coatings avoided coating-sector OHR emissions by 64% for the year of 2022. However, solvent-borne coatings still dominate daily OHR emissions (99%). Our future projection indicates that continuous substitution of solvent-borne coatings is still the most effective policy measure for reducing environmental impacts of coating sector emissions, which will gradually decline over the next two decades.