Data on formaldehyde sources, formaldehyde concentrations and air exchange rates in European housings

Formaldehyde has been discussed as a typical indoor pollutant for decades. To evaluate the current state-of-the-art in formaldehyde research and to identify the plethora of regulated and unregulated formaldehyde sources in indoor and outdoor spaces, an extensive literature search was carried out. The acquired data were analyzed with the aid of Monte-Carlo methods to calculate realistic formaldehyde concentration profiles and exposure scenarios under consideration of aging, source/sink behavior and diffusion effects. Average concentrations of formaldehyde are within 20–30 µg/m³ for European households under residential-typical conditions. The assumption of an average air exchange rate of 0.5 h(−1) is also plausible. Formaldehyde emission rates of materials and products for indoor use are widely spread and range from non-detectable to > 1000 µg/h. However, processes like combustion, cleaning activities, operation of air purifiers and indoor chemistry were identified as temporary but relevant formaldehyde sources, which might cause high peak concentrations.