Method development for measuring volatile organic compound (VOC) emission rates from spray foam insulation (SPF) and their interrelationship with indoor air quality (IAQ), human health and ventilation strategies

The polyurethane foam industry is projected to reach a worldwide value of up to $74bn by 2022 and with airtightness of new and retrofitted properties continually increasing, an important question arises: what is the impact of these materials on the indoor air quality (IAQ), occupants’ health and indoor environment? As the foams are made in-situ through an exothermic reaction between two chemical mixtures (side A and side B), volatile organic compounds (VOCs) are emitted during their application and curing process. Current research, commercial practices and governmental advice suggests that emissions decrease over time and 8-24 h after application are usually sufficient for residents to return safely to their properties. However, there is still a lack of case studies and a fundamental absence of robust analysis on how ventilation strategies affect long term off-gassing rates and chemical emission quantities. The emission rates from SPF materials could have a direct impact on IAQ if they exceed the occupational exposure rates recommended by NIOSH, or other professional associations. But the difficulty in recording these emission rates is evident as there is still a lack of an international standard for their quantification. To address this issue, we have developed an analytical methodology for measuring some of the composition materials of the foams and residual products associated with their application. The experiment consisted of two stages- active air sampling of spray foam emissions and spiking desorption tubes with a standard solution in order to develop calibration curves. The solution included SPF compounds, or by-products from their application, associated with possible acute impact on health: 1,4 dioxane, chlorobenzene, dibutyltin dilaurate, triethyl phosphate and bis(2-dimethylaminoethyl)ether. We managed to detect five of the chemicals of interest through air sampling and produce calibration curves for 1,4 dioxane, chlorobenzene and triethyl phosphate, which would allow us to quantify the emission rates at the next stage of research. The results of the experiments successfully demonstrated proof of concept quantitative methodology for the compounds of interest. With further research and experiments, this technique has the capacity to be developed into an international standard for measuring VOCs from spray foam emissions and other buildings products. This would provide scientists and industry professionals with the tools to further develop retrofit and ventilation strategies in order to provide healthier buildings.