Modeling the formation and growth of organic films on indoor surfaces

Emission, transport, and fate of semi‐volatile organic compounds (SVOCs), which include plasticizers, flame retardants, pesticides, biocides, and oxidation products of volatile organic compounds, are influenced in part by their tendency to sorb to indoor surfaces. A thin organic film enhances this effect, because it acts as both an SVOC sink and a source, thus potentially prolonging human exposure. Unfortunately, our ability to describe the initial formation and subsequent growth of organic films on indoor surfaces is limited. To overcome this gap, we propose a mass transfer model accounting for adsorption, condensation, and absorption of multiple gas‐phase SVOCs on impervious, vertical indoor surfaces. Further model development and experimental research are needed including more realistic scenarios accounting for surface heterogeneity, non‐ideal organic mixtures, and particle deposition.