OBJECTIVES: We report an outbreak of skin disorder in semiconductor packing workers. Through an evaluation of the degree of work-relatedness in this case, we aim to develop a method to overcome such health problems in the workplace. METHODS: A questionnaire investigating the job characteristics and skin symptoms was administered to 51 packing workers working in a semiconductor production factory and 49 questionnaires returned. The 16 subjects in the exposure group and 12 in the non-exposure group underwent doctor's examination and patch test. Two of 28 subjects were excluded in patch test. We investigated the work environment and carbon fiber level which was the potential causative agent. RESULTS: Forty-five (91.8%) of 49 packing workers complained of itching and stinging. Three of 14(21.4%) in the exposure group and 3 of 11 (27.3%) in the non-exposure group were positive at 48hr reading of patch test for carbon fiber and carbon fiber paper. None was positive at 96hr reading of patch test. Prominent carbon fibers were microscopically observed on the surface of the packing box and the fiber diameter, measured up to 6.0~7.5 micrometer, was likely to induce skin irritation to skin. To avoid worker's direct contact with to carbon fiber, carbon fiber paper box was substituted by a wax coated carbon fiber paper box was substituted for the original carbon fiber paper box, which caused and the workers' symptoms to of workers disappeared. CONCLUSION: The probably cause of this outbreak of skin disorder was mild irritant contact dermatitis for carbon fiber. To prevent outbreaks of such occupational skin disorder like this, workers should avoid direct contact with carbon fiber.