Standards for exposure to ethylene oxide are currently being reevaluated with the possibility of more stringent standards being permanently retained. Monitoring techniques are described; both the portable infrared analyzer and the infrared monitor with microprocessor are mentioned. Contamination occurs when there are leaks on the lines carrying the gas to the sterilizer, when the sterilizer is opened, and from outgassing of the material that has been sterilized. -- AATA