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

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.