On-line monitoring of solvent emission rates using an open path FTIR analyser

Solvent mixture concentrations in paint and resin manufacture were on-line monitored using a portable open path Fourier transform infrared (OP-FTIR) analyser in order to determine solvent emission rates into workspaces. The mean solvent emission rate was 0.46 kg/h in paint production and 0.35 kg/h in resin manufacture. Expressed as emission factor, i.e. evaporated portion of the total solvent mass used, the corresponding values were 0.01% for paint production and 0.1% for resin manufacture. The OP-FTIR instrument together with advanced spectra analysis software facilitated a rapid identification of solvent mixtures and on-line concentration monitoring with good temporal resolution. The analyser seems to be particularly useful in industrial hygiene applications where spatial average concentrations are needed. The further benefit of the open path instrument is that no sampling lines, pumps or sample cells are needed.