The hazards and good work practices needed when health care workers are exposed to ethylene oxide (75218) (EtO) were discussed. The use of EtO as a sterilizing agent in health care facilities has been widespread and acute exposure to EtO have been shown to cause eye, nose and throat irritation, skin burns and allergic sensitization. OSHA has set the permissible exposure limit at was 1 part per million (ppm) as a time weighed average over the 8 hour workday. NIOSH has recommended a time weighed average of 0.1ppm and that exposure to 5ppm EtO be limited to 10 minutes. Most hospitals using automatic general purpose gas sterilizers have been using EtO concentrations of 600 to 1100milligrams/liter. With proper humidity, sterilization takes less than 2.5 hours at 130 degrees-F and over 5 hours at 100 degrees-F. A 12 hour aeration period is generally needed after sterilization. Significant EtO exposure has been caused by small amounts of EtO found in the sterilizers. The best way to reduce the potential for exposure is to use sterilizers with in chamber aeration. If this is not possible, multiple poststerilization EtO reduction cycles should be run. In pressurized sterilizers, an antisiphon air gap is enclosed and ventilated between the discharge of the vacuum pump and the sewer piped drain. In single cartridge sterilizers, frequent leak checks of the discharge line should be made. Care should be taken in the placement of EtO exhaust ducts to prevent the intake of exhausted gas into the building ventilation system. Finally, the author suggests that a proper emergency response plan is needed in case of accidental EtO release.