Comment Submissions - Updated No Significant Risk Level for Ethylene Oxide

Monitoring Ethylene Oxide Emissions Dear OEHHA, On behalf of our community of ethylene oxide (EtO) sterilization facilities, I write to advocate for the broader adoption of the Cavity Ring-Down Spectroscopy (CRDS) system and Other Test Method 47 (OTM-47) in place of incumbent technologies, for the continuous monitoring of EtO emissions as per the regulations of 40 CFR 63, Subpart O. Given the recent advancements in CRDS technology, it offers significant improvements in sensitivity, precision, and reduced operational costs over the Fourier Transform Infrared Spectroscopy (FTIR) and gas chromatography (GC) systems. Our observation of various commercial sterilizers employing the Picarro CRDS systems have demonstrated a consistent efficiency in the analysis of sample matrices with profoundly improved specificity over other technologies. The CRDS-based Continuous Emissions Monitoring Systems (CEMS) deliver a level of detection (LOD) of