case of a chronic lymphatic leukemia (CLL) of a chemicals worker, who was exposed to ethylene oxide (EO) at the workplace for several years, is presented. From the occupational health point of view, it must be assessed whether CLL, according to the new classification of Non-Hodgin lymphoma, fulfils the preconditions of an occupational disease. The decisive factors for the causality assessment are the current findings on the human carcinogenicity of ethylene oxide, the estimation of the quantitative risk after occupational exposure to EO and the assessment of temporal processes between exposure and disease.
