Polymer materials and their additives are today ever present in our daily surroundings. These materials have been found to emit a number of different volatile organic compounds (VOCs) into the ambient air, thus affecting the quality of the indoor air VOCs with detectable concentrations are exchanged between the different materials and indoor air. Materials present in the system act as sorbents as well as sources of emission, depending on the concentration of the VOCs in the air at a specific time. This work demonstrates a method of studying the phenomena of absorption/re‐emission. A hypothetical room that resembles a furnished office has been studied. A PVC flooring material was used as a primary emission source in a system where materials such as wood, paint, cloth, chipboard, and cellulose were present. Mass transfer in the solid materials was assumed to be by diffusion. The results show that the mechanism of absorption/re‐emission of volatiles may extend the time of residence in an indoor system considerably. A person working in this environment could risk longer exposure to toxic volatiles than if there were no absorption/re‐emission effects.

In this paper the use of a thin adsorbent sheet composed of activated carbon particles to purify indoor air is modelled. A loose sheet with high porosity appears more effective than a dense one. The carbon sheet can be replaced by a fresh sheet after a certain period of use, thus keepilzg the volatile organic compound (VOC) level low in the remaining years. The model has been used to predict the optimal replacement time. Binary VOCs are modelled. The results turn out to be close to those from single component calculations, which suggests that the efficiency of the carbon sheet to one VOC is negligibly affeaed by the presence of other VOCs at ppb levels.