Formaldehyde, which is recognized as a harmful indoor air pollutant for human health, is emitted from urea-formaldehyde resin in wood products. Chamber tests are used to evaluate formaldehyde emission rates from these products. However, there is no available formaldehyde standard reference emission source to assess the overall performance of chamber testing systems. In this paper, a LIFE (liquid-inner tube diffusion-film-emission) formaldehyde reference is described. The formaldehyde source consists of a polytetrafluoroethene (PTFE) tube that holds a 16 % (by volume) formaldehyde-water solution, with a thin polydimethylsiloxane (PDMS) film cover. Formaldehyde emission parameters for the PDMS film (diffusion coefficient and partition coefficient) were determined experimentally, thereby enabling the prediction of the emissions in a chamber for use as a reference value. Chamber tests were conducted in a 51 L stainless steel ventilated chamber. The impacts of temperature and relative humidity on the emissions were also investigated. Results show the LIFE's chamber testing results match those predicted by a mass transfer model. As a result, this formaldehyde source may be used to generate a reference concentration in product emission testing chambers, thereby providing a powerful tool to evaluate the performance of the chamber testing systems.
Citation: Environmental Science & Technology
Pub Type: Journals
chamber testing, emissions, formaldehyde, indoor air quality, materials, reference material, source