Concentrations of Formaldehyde in new Danish Residential Buildings in Relation to WHO Recommendations and CEN Requirements

Abstract

It is uncertain if current Danish legislation regarding emission of formaldehyde from wood-based panels could assure that concentrations of formaldehyde in the indoor air of buildings containing the material would meet the World Health Organization (WHO) guideline. This is of particular concern since the recent recognition by International Agency for Research on Cancer that formaldehyde is carcinogenic to humans. Therefore, the purpose of this study was to determine whether residents of newly built Danish residential houses could be exposed to safe levels of formaldehyde. Geometric mean concentration of formaldehyde measured in 20 residential buildings was 0.04 mg m⁻³. Formaldehyde concentrations in two buildings (10%) exceeded the WHO guideline value. In order to explain the relatively high concentrations, a second phase was performed. The aim was to identify the significant formaldehyde sources and to discuss the source strength in relation to field measurements and WHO guidelines. The results showed wide differences between the materials tested, but all steady-state concentrations were below the European standard requirement for class E1. These measurements formed the basis for model calculations of possible resulting concentrations in residential rooms, suggesting that indoor concentrations above the WHO maximum limit could occur. The calculations applied a worst case scenario with all surfaces covered with materials emitting the maximum permissible amount of formaldehyde show indoor concentrations as high as 0.6 mg m⁻³.