In December 2016, the U.S. Environmental Protection Agency (EPA) finalized its evaluation of the inhalation carcinogenicity from long-term inhalation exposure to ethylene oxide (EO). The results were published via the Agency’s Integrated Risk Information System and indicated an increased carcinogenic potential for exposure to airborne EO. This resulted in increased public scrutiny of industrial facilities operating with EO and subsequently led to a need for the industry to better characterize and control EO emissions and leaks.
Accurately characterizing EO emissions requires techniques that are capable of measuring EO at concentrations ranging from parts-per-trillion (ppt) in ambient air to parts-per-million (ppm) in process streams. The choice of measurement technology that best suits the task at hand depends on expected EO concentrations, existing sample gas conditions, the presence of potential measurement interferants, and the ultimate project objectives. Cavity Ring-Down Spectroscopy (CRDS) is capable of generating rapid and precise measurements of EO at ultra-low and ppm-level concentrations, which is a prerequisite for its use in industrial applications.
This paper discusses the use of CRDS as part of a Continuous Emissions Monitoring System (CEMS) at affected facilities, for process measurements before and after air pollution control equipment, and as a tool to complement ongoing leak detection and repair (LDAR) programs.
