We surveyed training, the use of protective devices, personal and environmental exposure levels and self-reported short-term health complaints amongst 165 health care workers (response = 76 per cent) using ethylene oxide (EtO) sterilizers in 27 hospitals in the province of Alberta, Canada. Data were collected via self-administered questionnaires. Personal and environmental sampling was carried out during site visits to 18 hospitals. Although no detectable levels of EtO were found in environmental samples, over half of the respondents stated they could smell EtO at work. While sampling results never revealed concentrations above the provincial 15 min time weighted average short-term exposure limit (STEL; = 50 p.p.m.), personal exposure concentrations and the use of portable sterilizers were positively associated with short-term symptoms such as irritations of the mucous membranes and skins (P less than 0.05).