Hexahydrophthalic acid in urine as an index of exposure to hexahydrophthalic anhydride
Post-shift and next-morning urine was sampled from workers exposed to hexahydrophtalic anhydride (HHPA), an epoxy hardener, sensitising at low exposure levels. Exposure levels of HHPA in air (gas chromatography, GC) in the range of 30-270 micrograms/m3 corresponded to urinary concentrations of 0.9-2.8 mumol hexahydrophthalic acid (HHP acid; GC-mass spectrometry)/mmol creatinine. In the morning sam