Evaluation of Micro-Scale Chambers for Measuring Chemical Emissions from Spray Polyurethane Foam Insulation

摘要

Consensus standards are being developed at ASTM International to identify potential emissions from spray polyurethane foam (SPF) insulation products and to evaluate their impact on indoor air quality after installation. A method is currently being developed to measure emissions of SPF insulation using micro-scale chambers. In order to evaluate emission decay rates and the effects of temperature, generic SPF formulations (closed-cell and open-cell) were tested for emissions in micro-scale chambers (0.114 L) at ambient (23°C) and two elevated temperatures (40 and 65°C) for 20 days. Small-scale chamber (36-L) tests were conducted simultaneously to correlate the emission factors that were measured with the micro-scale chambers. Thermal desorption gas chromatography-mass spectrometry was used to capture and quantitate target volatile organic compounds (blowing agents, amine catalysts, etc.) and the flame retardant used in both formulations. Aldehydes were captured onto silica gel sorbent tubes with dinitrophenylhydrazine and analyzed with high-performance liquid chromatography. After the application of open-cell SPF, the outer skin layer of the foam may be trimmed to align the surface with wall studs or other structural elements. In this case, it may be necessary to mimic this practice when preparing samples for analyses to measure emissions. In order to investigate the impact of emissions on trimmed SPF samples, micro-scale chamber studies were conducted on both trimmed and untrimmed generic open-cell SPF material for comparison. The data from this study demonstrate that micro-scale chambers can be used to identify and quantitate potential emissions from SPF insulation. The findings from this research will be used to support the development of consensus standards in ASTM Committee D22 on Air Quality, Subcommittee D22.05 on Indoor Air.