Quantitative determination of phosgene doses by reflectometric badge readout

Commercial phosgene dosimeter badges are lacking precise and sensitive analysis when used only by visual comparison to a color reference. To meet the discussed occupational standard set to 54 ppm min, objective quantification by reflectance measurement is proposed. At 573 nm, the pink dye ("Koeniǵs salt") formed at the membrane surface by reaction of phosgene, and aromatic amine shows a strict linear relationship in reflectance between doses of 10 and 300 ppm min. The detection limit is calculated to 29 ppm min.