Conclusions
Isocyanate emissions are at hazardous concentrations near the stack when spraying is occurring. However, isocyanate spray time is relatively short (2-15% of day)
Ground level (perimeter) concentrations are very low
There appears to be adequate plume dispersion – the plume is seen to rise and disperse
Solvent vapour concentrations at the stack are at marginally-hazardous levels
Solvent vapours at ground level are very low, but there may be an odour depending on wind direction
Work outside the booth may generate nuisance levels of solvent vapour
The lowest concentration of isocyanates and solvents were found for a booth with a charcoal filter