VOCs and aldehydes source identification in European office buildings - The OFFICAIR study

Indoor air quality (IAQ) measurements were carried out in two field campaigns (summer and winter) in European office buildings (approximately 140 office rooms) in eight countries, as part of the EU-funded OFFICAIR project. A source identification study was performed with principal component analysis (varimax rotation) on a database containing volatile organic compound (VOC) and aldehyde concentration data during summer and winter monitoring campaigns. The common indoor and outdoor sources of VOCs and aldehydes were identified through a critical evaluation based on checklist data and knowledge of material and product emissions from the literature. The dominant source of variance, accounting for 29% and 26% of the explained variance in the summer and winter campaigns, respectively, was attributed to the ingress of outdoor air into indoor environments. The other most relevant sources for variance were directly or indirectly associated with building materials, such as flooring materials (in particular carpets), wood-based products and various types of paint. Ozone-initiated indoor air chemistry played a key role only during summer, in which a specific source linked to ozone-initiated reactions was clearly identified. Other indoor sources explained less than 10% of the variance, such as printer emissions in both campaigns and cleaning products in winter. •VOCs and aldehydes were sampled in European offices to identify emission sources.•The major VOC sources are of outdoor origin in both seasonal campaigns.•The other important sources derive from building material emissions.•Ozone-initiated reactions were clearly identified only in summer.•Less prominent sources are linked to cleaning products and office equipment.