Isocyanatemissionen bei der Verarbeitung von Polyurethanklebstoffen

Emissions of monomeric diisocyanates were evaluated by measuring the specific emission rate (area) (SERa in µg/m2h) in a 2.2 l emission chamber. Therefore the SERa presents a material specific value. The influence of temperature on the emission rate could be shown to follow thermodynamic laws i.e. that is an exponential increase of emission with temperature. Evaluation of emission rate for different commercially available PUR-adhesives showed highest emission for systems which were applied at high temperatures. Also volatile isocyanate by-products could be detected from some room temperature curing systems. For upscaling of emission experiments in a 1-m3 emission chamber it was found that the strong and irreversible adsorption of isocyanates should be taken into account when modelling real concentrations in air. Field studies at four different work sites confirm tendencies found for the emission rates.