Formaldehyde Emissions from Urea-Formaldehyde- and No-Added-Formaldehyde-Bonded Particleboard as Influenced by Temperature and Relative Humidity

It is well documented that temperature and humidity can influence formaldehyde emissions from composite panels that are produced using urea-formaldehyde (UF)-type adhesives. This work investigates the effect of temperature and humidity on newer commercial California Air Resources Board (CARB) phase II-compliant particleboard produced with UF-type adhesives. These results were compared with laboratory particleboards prepared with the no-added-formaldehyde (NAF) Soyad adhesive technology. A modified version of EN 717-3 ("Formaldehyde Release by the Flask Method," ONORM 1996) was used to collect formaldehyde emissions that were quantified using the acetylacetone method. The formaldehyde emissions from the commercial particleboard panel bonded with a UF-type resin increased greatly when panels were exposed to higher heat and humidity than in normal testing protocols. Furthermore, the rate of emission for these UF-bonded panels increased with longer exposure at 100 percent relative humidity. In contrast, formaldehyde emissions from particleboard bonded with the NAP adhesive were relatively stable and significantly lower compared with those bonded with UF at all temperature and relative humidity conditions. This work highlights the potential for increased long-term formaldehyde emissions even from the new UF CARB phase II-compliant adhesive systems.