VOC Sink Behaviour on Building Materials – Model Evaluation

Abstract

The event of 11 September 2001 underscored the need to study the vulnerability of buildings to weapons of mass destruction, including chemical, biological, physical and radiological agents. Should these agents be released inside a building, they would interact with interior surfaces, building materials and furnishings, and could remain for a long period in an indoor environment. This study provides insights into the sink effect and absorption mechanisms of volatile organic compounds (VOCs) in indoor environments. In this study, the sink effect was investigated with building materials (e.g. painted gypsum wallboard, vinyl flooring, carpet and mortar) and VOCs, ethylbenzene, 1-butanol, decane and dodecane, which were used as surrogates of toxic chemicals. Vinyl flooring has the strongest sink for ethylbenzene and dodecane. The sink experimental data were employed to evaluate the Langmuir-isotherm and diffusion sink models. Test data were also compared to a no-sink model. The sorption and desorption rate constants for the Langmuir-isotherm model were obtained. Mass balance was analysed. There were strong correlations between equilibrium partition coefficients from the Langmuir-isotherm model and equilibrium partition coefficients and the effective diffusion coefficients from the sink diffusion model.