ETHYLENE OXIDE: HAZARD CHARACTERIZATION AND EXPOSURE–RESPONSE ANALYSIS

Ethylene oxide has been assessed as a Priority Substance under the Canadian Environmental Protection Act. Based on studies in animals, cancer is considered the critical endpoint for effects of ethylene oxide on human health. In inhalation studies, ethylene oxide has induced a wide range of tumours, with a strong likelihood that the mode of action involves direct interaction with genetic material. Tumorigenic Concentration05s (i.e., concentrations associated with a 5% increase in tumour incidence above background), derived from a study in animals with optimal characterization of exposure–response, ranged from 2.2 to 31.0 mg/m3.