Abstract Background Hazardous substances at the workplace can cause a wide variety of occupational incidents. This study aimed to investigate the nature and circumstances of acute occupational intoxications reported to the Dutch Poisons Information Center. Methods During a one-year prospective study, data on the circumstances and causes of the incident, the exposure(s) and clinical course, were collected by a telephone survey with victims of an acute occupational intoxication. Results We interviewed 310 patients. Most incidents occurred in industry (25%), building and installation industry (14%) and agriculture (10%). Patients were often exposed via multiple routes. Inhalation was the most common route of exposure (62%), followed by ocular (40%) and dermal contact (33%). Acids and alkalis were often involved. Exposure often occurred during cleaning activities (33%). The main root causes of these accidents were: technical factors such as damaged packaging (24%) and defective apparatus (10%), organizational ...