Ventilation rates in relation to emission of gases and vapours from building materials.

Uses mathematical models for formaldehyde concentrations in 3 normal rooms in a single family house to estimate ventilation rates needed to maintain the formaldehyde concentration below the Danish recommended indoor standard (0.15 mg/m*3). It appears that in an initial period after the house is finished, a ventilation rate more than 10 times the recommended Scandinavian value (0.5air changes/hr) is needed to keep the concentration below the indoor standard. In consequence it is proposed that ventilation standards are set for theinitial period and also the following period when emissions are in a more steady state. In the initial period occupants should be advised to ventilate as much and as often as they feel necessary and new houses should be constructed with extra permanent or temporary ventilation facilities.