Ethylene Oxide (EtO) is known to exhibit a number of biological effects which include irritation, organ damage, mutagenicity and carcinogenicity in human and animals, and reproductive effects in animals. When determining the suitability of ethylene oxide for sterilization of medical devices, it is important to ensure that the levels of residual EtO, ethylene chlorohydrin (ECH) and ethylene glycol (EG) pose a minimal risk to the patient in normal product use.