VOC sorption and diffusion behavior of building materials

In this study 25 different building materials often used in timber constructions (wood based panels, gypsum boards, vapor barriers, adhesive tapes, insulation materials and sealants) were investigated with regard to their adsorption, desorption and diffusion behaviour towards volatile organic compounds (VOC). The materials were exposed to four, respectively five selected VOCs typically found in indoor air: hexanal, butyl acetate, p-xylene, nonane and alpha-pinene. Adsorption and desorption properties were investigated under static conditions, whereas the diffusion behavior was examined in a 0.225 m(3) emission chamber with an air exchange rate of 1 h(-1). The results of the experiments indicate that some building products have a high potential to reduce VOCs in indoor air. Apart from the vapor barriers, two insulating materials and one plasterboard, all tested materials represented an adsorption efficiency of about 50 % or higher related to the injected VOC standards. Materials with high adsorption capacity bound substances strongly and desorbed them less, whereas less adsorbing materials acted inversely. The obtained results indicate that material properties and processing play a considerable role in diffusion behavior of building materials.