Field Evaluation of Direct-Reading Continuous Ethylene Oxide Monitors

The Wilford Hall USAF Medical Center Central Processing Section WHMCSGLP uses ethylene oxide EtO as a primary sterilizing agent. Because of their concern about the health effects of EtO, SGLP has searched for a continuous monitoring EtO system. In their search, they found two units AMSCOs Envirogard III and Baseline Industries, Inc.s Model 5500 Gas Analyzer. The objective of this evaluation was to conduct a field study to compare the performances of the two direct-reading continuous EtO monitors against the Occupational Safety and Health Administrations OSHA acceptable charcoal tube sampling method. In addition, the 3M EtO passive monitor sampling method was compared with the charcoal tube method and direct-reading instrumental method as well. Neither the Baseline Industries, Inc. nor the AMSCO continuous monitors corresponded to OSHA acceptable charcoal tube method of air sampling. Both instruments reported EtO concentrations much higher than those detected by the charcoal tubes. There is no way of knowing which method, the direct-reading continuous monitor or the charcoal tubepassive monitor, is more correct. However, the OSHA standard for EtO is based on measuring EtO by the charcoal tube method. Keywords Air pollution, Industrial medicine.