An Ethylene Oxide (EtO also known as dimethylene oxide oxirane oxacyclopropane) Monitor is a device used to monitor the Ethylene Oxide output on serilizing equipment. The purpose is to help employers understand how to monitor the quality of the air in workplaces where ethylene oxide (EtO) is processed, used, or handled. Air monitoring is an important activity that can help alert employers when unsafe levels of EtO are present in the air so that they can take steps to reduce employee exposure. EtO can be used more safely if appropriate precautions are taken and if equipment is adequately designed and maintained. All of the required actions presented in this document are based on OSHA's EtO standard (29 CFR 1910.1047).