Laboratory Intercomparison of Multiple Ethylene Oxide Measurement Methods Under Simulated Near-Source Monitoring Conditions

Ethylene oxide (EtO) is a widely used industrial chemical that poses potential health risks due to its carcinogenic and mutagenic properties. Accurate and reliable measurement of EtO concentrations is crucial for assessing public health risks and regulatory compliance. However, the lack of a standard reference method for EtO measurement poses significant challenges for researchers and analysts. In this study, we compared various EtO measurement methods under simulated, atmospherically relevant, laboratory conditions by investigating the impact of water vapor, potentially interfering gases (including carbon monoxide, methane, ethane, ethylene, propane, propylene, propylene oxide, and formaldehyde), ammonium sulfate aerosol, and photochemical reactions on measurement accuracy and reliability of real-time and time-integrated measurement techniques. Our findings revealed that the choice of the EtO analytical approach significantly impacts the measurement accuracy and reliability, particularly when testing conditions deviate from ideal laboratory settings. Selecting an appropriate EtO measurement method requires considering these limitations and their impact on accuracy and reliability. This study generated instrument performance data to guide researchers and analysts in making informed decisions about EtO measurement techniques and to facilitate the development of standardized methods for EtO measurement in a variety of environmental settings.