Toluenediamine in polyurethane foams Hazard or artefact?

Abstract

The aim of this study was to investigate the formation of the suspected carcinogen toluenediamine (TDA) as a degradation product of polyurethane. For this purpose, a series of model systems was prepared, including linear polyurethanes and foams. The starting materials were fully characterised using melting point and refractive index determination, end group analysis, infrared spectroscopy, nuclear magnetic resonance spectroscopy and coupled gas chromatography–mass spectrometry (GC–MS). A model commercial polyurethane foam was also prepared. Three different solvent extraction protocols were applied and the extracts analysed by coupled GC–MS and high performance liquid chromatography–mass spectrometry. No detectable amounts of TDA could be found in extracts of both linear polyurethane and foam incubated using either toluene or 1% acetic acid solution. By contrast, TDA was found in extracts from both linear polyurethane and foam that had been exposed to alkaline conditions during the extraction procedure. These findings confirm that the formation of TDA in extraction and GC–MS analysis of polyurethane samples results from hydrolytic degradation processes of polyurethane and that alkaline conditions should be avoided during extraction and analysis.