Occupational dermatitis from soldering flux

The aim of this study was to determine the specific agent responsible for eczema on the forearms of 2 electronic assemblers who cleaned out a flux-spraying unit once a week. Soldering flux can be a source of skin irritation as well as allergy. Patch test with dried flux residue (as is) and rosin in dilution series of 20%, 10%, and 1% in olive oil was performed. Readings were taken on day 2 and day 3. The rosin in dilution series was negative; however, the flux residue gave a + reaction on day 2, and by day 3 the reaction had weakened (+?). Similar results were obtained in 2 unexposed controls. Patch tests results in our cases indicate that the flux used in the soldering process caused irritant contact dermatitis.