The relation between emission-rates of organic gases etc from building materials and their concentrations in the indoor environment

Individual mathematical models for formaldehyde concentrations in each of 3 normal rooms in a single family house is used to estimate ventilation rates needed to maintain formaldehyde concentration below the recommended Danish indoor standard (0.15 mg/m3). In an initial period after the house was finished a ventilation rate more than 10x the recommended Scandinavian maximum value (0.5 ach) was needed to keep the concentration below the indoor standard. It is proposed that ventilation standards are set not for the initial period but for the following period where emissions are in a more steady state. New houses should be constructed with extra permanent or temporary ventilation facilities to control preliminary formaldehyde concentrations.