Comment-21105-anonymous

Subject: Support for Cavity Ring-Down Spectroscopy (CRDS) in Compliance with Revised Workplace Exposure Levels

Dear California Office of Environmental Health Hazard Assessment (OEHHA),

I write in support of industry, the Ethylene Oxide Sterilization Association, Inc. (EOSA), their comments regarding the proposed revision to Section 25705, but also in support of altering the No Significant Risk Level (NSRL) for ethylene oxide (EtO) aimed at protecting workers. As monitoring technology expert and service provider, I am aware of many different technologies for monitoring EtO and other gases in stacks, workplaces, fence lines, and process applications - there are significant technology advancements I would like the State of California and the EPA to consider.

Organizations like EOSA and medical device companies have aptly expressed the significance of EtO in the sterilization industry, especially in maintaining the safety standards for healthcare products and spices. While the intention of reducing the NSRL for EtO is well-understood and appreciated from a public health perspective, it is crucial that these changes are not only supported by robust and unbiased scientific evidence but also a thoughtful consideration to the available monitoring technologies on the market today.

This brings me to an important suggestion - the adoption of Cavity Ring-Down Spectroscopy (CRDS) as a monitoring system for EtO exposure, fenceline, and stack monitoring. CRDS offers several advantages over other detection methods such as Gas Chromatography (GC) and Fourier Transform Infrared Spectroscopy (FTIR). There are also CRDS based test methods already available and developed specifically for EtO including the recent release of EPA Other Test Method 47 (OTM-47) and Performance Specification-19, which has proven CRDS to show far superior performance over unreliable technologies such as optically enhanced FTIR's (MAX Starboost), mass spectrometers, and gas chromatography, and passive techniques (canisters) both in specificity and ease of use. Other performance parameters evaluated by third party testing companies and industrial facilities are widely noted and include the following:

Sensitivity and Accuracy: CRDS, due to its long optical path length, provides high sensitivity and precision. This high resolution will assist in monitoring even the minor fluctuations in EtO exposure that can be crucial, given the new proposed stringent NSRL.

Real-Time Monitoring: CRDS offers continuous and real-time monitoring capabilities. This can provide immediate feedback and can help industries quickly adapt their operations to ensure they are within safe levels while providing the necessary time-averaging and resolution needed to provide consistent and reliable data.

Unbiased Measurement: Unlike GC and FTIR, CRDS doesn't depend on the chemical properties of the target molecules for detection, reducing the possibility of bias and providing a more accurate representation of actual exposure levels. CRDS has also proven to be a direct and specific measure of EtO while simultaneously measuring all other compounds in the matrix in real-time. On the other hand, optically enhanced FTIRs have shown be susceptible to low levels of water vapor and various interfering hydrocarbons which cause false spikes in the EtO measurement.

Low Maintenance: CRDS systems are known for their robustness and require minimal upkeep. This makes the technology both economical and reliable for long-term monitoring purposes.

Revising the NSRL for EtO is a significant move towards protecting public health. However, to ensure that the new standards are met, while not hindering the vital sterilization work carried out by medical device manufacturers, I urge you to consider guiding sterilization facilities to use CRDS-based methods which are already approved for use in CEMS and workplaces while also pushing for the development of new methods for real-time CRDS fenceline compliance monitoring.

Thank you for your attention to this matter. We appreciate the ongoing commitment of OEHHA to ensure the safety of the public while supporting industries that are crucial to healthcare and food safety.