An Investigation into Claims that Toluene Diamine (TDA) is Present in Polyurethane Flexible Foams

Claims have been made in Scandinavia that polyurethane flexible foams can be a health hazard because they contain, or on ageing can form, traces of the carcinogenic substance 2,4-toluene diamine (TDA). A working group was set up to investigate these claims and some of their findings are reported here. Analytical protocols have been refined for the determination of TDA extractable into aqueous based media. Extensive testing has been carried out on many different kinds of polyurethane foam without any evidence being found for the presence of free TDA. These negative results apply to both fresh cured foam and foam treated to simulate heat ageing, autoclaving and use in humid conditions. The reason for the erroneous reporting of TDA in foams undoubtedly lies in the use of the wrong pretreatment of the extract or the use of inappropriate sample injection techniques. This could range from not filtering the extract, increasing the pH of the extract prior to either gc/ms or lc/ms detection, or using hot on-column injection gc techniques. The false reporting of TDA is demonstrated here.