Exposure to hydrophthalic acid anhydrides during work with epoxy resins in electrical engineering

In electrical engineering, casting resins containing epoxy resin are used among other things in the production of capacitors, coils and transformers. Hydrophthalic acid anhydrides are mainly used as the hardeners, These substances may trigger sensitization of the respiratory organs. To determine the extent of the risk, the BG ETEM (BG for energy, textiles, electrical engineering and media products) conducted controlled measurements of hydrophthalic acid anhydrides in the air at workplaces from 2004 to 2009 (sampling XAD-2, analysis GC/FID). For the four investigated hydrophthalic acid anhydrides, concentrations ranging from 0.01 to 0.60 mg/m(3) were found. Limit values are not currently available for these subjects, although there is evidence in the literature that concentrations exceeding 0.050 mg/m(3) have given rise to elevated sensitization rates among employees. If this value is referred to for an assessment of exposure, work areas can be identified in which this concentration is exceeded. Measures should be taken to protect employees. These are described in detail.