Ensuring PS-19 Compliance: Advanced CEMS Solution for Commercial Sterilizers

This article outlines the regulatory framework behind the recent changes in the Commercial Sterilizer NESHAP (40 CFR 63 Subpart O). It will discuss how the US EPA came to a decision on the continuous emissions monitoring requirements, as well as what those requirements are.

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Throughout the sterilization industry, many are concerned when it comes to meeting these requirements, as previous technologies have struggled to demonstrate the response necessary to demonstrate compliance. This article will delve into the Performance Specification 19 (PS-19), which outlines an approved framework that a facility can follow to certify its Continuous Emissions Monitoring System (CEMS).

Following on from this, the processes that occur after certification will be discussed, as well as how a facility can maintain continual compliance if it is subject to 40 CFR 63 Subpart O.

After navigating the required components of CEMS compliance, Picarro Inc. introduces how it can help when it comes to ensuring federal regulatory compliance.

The Regulatory Landscape

The Clean Air Act (CAA) is the primary federal air quality law in the US. It is extensive and includes a variety of topics related to air quality.

The US EPA was in charge of coming up with the legal mandates and has established several regulatory programs to do this, two of which are relevant to Performance Specification 19 (PS-19); National Emission Standards for Hazardous Pollutants (NESHAP) [40 CFR Part 63] and New Source Performance Standards (NSPS) [40 CFR Part 60].

It is interesting to note that the NSPS laid the foundation for emissions monitoring and is most known for its regulations on criteria pollutants, whereas NESHAP tends to focus more on hazardous air pollutants – such as ethylene oxide (EtO).

Across most of the US, the administrative responsibilities derived from CAA tend to be delegated to the respective state and tribal authorities. Despite this, the EPA is still responsible for completing research and offering technical guidance to the States.

While the overarching requirements apply to the entire country, there can be differences in how states choose to administrate. This leads to a variety of jurisdiction-dependent experiences for the regulated community.

PS-19 is included in Appendix B to Part 60 and explains the processes that are required when installing and certifying a CEMS. In addition, Part 60, Appendix F contains Quality Assurance Procedure 7, outlining the structure for maintaining CEMS compliance following certification.

PS-19 – What is it?

PS-19 can be found in Appendix B of Part 60 and is regarded as the most quality assurance-focused and detailed performance specification to date. The specification is made up of six main tests, as well as a stipulation on the use of a time-shared system.

PS-19 starts off using similar requirements to most CEMS – it demands the use of certified reference gases, meeting the “EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards.” However, as PS-19 also deals with extremely low-concentration gases, protocol gases can be diluted using EPA Method 205 to meet the required values.

To ensure that the CEMS measurement point is free from stratification and delivers accurate readings, the CEMS must be installed at least two equivalent duct diameters downstream from any control device or flow disturbance and at least half an equivalent duct diameter away from any exhaust or control device.

PS-19 also mandates the measurement of volumetric flow rate and, if EtO measurements need to be adjusted for moisture content, the measurement of this moisture. The flow monitor should be positioned in compliance with these conditions but must also not exceed half a duct diameter from the CEMS probe.

If moisture measurement is required, the system must either include a continuous moisture sensor and an oxygen analyzer capable of measuring oxygen levels on both wet and dry bases or use an optical measurement system approved by EPA Method 301.

The CEMS must be capable of providing at least one valid measurement at each measurement point every 15 minutes. This specification permits the use of a time-sharing system, which involves monitoring multiple points with a single analyzer.

If these requirements are met and the system is properly installed, set up, and calibrated, the facility can proceed with the Performance Specification Test Procedures.

Those Tests are Briefly Summarized Below:

Source: Picarro 

1. An interference test is also considered successful if the total of the interference responses does not exceed 2.5 % of the calibration span or ±3.0 % of the equivalent EtO concentration used.
2. If the average RM emission level is below 50 % of the EtO concentration or emission standard, the emission standard may be used in the denominator of the RA calculation, with results required to be ≤15 %.
3. OTM-47 is used for the initial RATA testing.

Maintaining CEMS Compliance

After completing the necessary quality assurance tests, facilities must submit the results to the relevant administrator for certification approval of their CEMS. Subsequently, facilities are required to perform regular preventative maintenance on their CEMS in accordance with 40 CFR 60, Appendix F Quality Assurance Procedure 7.

Navigating the complexities of CEMS maintenance and understanding these requirements can be challenging, especially for facilities without prior experience with these sophisticated systems. CEMS components include consumables as well as critical parts that may fail unless regularly inspected and/or replaced. Consequently, 40 CFR Part 63, Subpart A mandates that facilities maintain an inventory of spare parts and a spare parts list to facilitate timely repairs.

Moreover, each facility must develop a quality assurance plan that outlines the procedures necessary for maintaining an operational CEMS. This task can be daunting, and even facilities experienced in power generation often rely on specialized consulting firms to develop or update these plans.

Recognizing this widespread need, Picarro offers each client a tailored quality assurance plan that includes all necessary components and additional details with their purchase.

Additionally, commercial sterilizers are federally required to submit semi-annual compliance reports and quality assurance test reports through the EPA’s Electronic Reporting Tool (ERT).

Procedure 7 Details

Procedure 7 stipulates essential requirements for maintaining a compliant CEMS, which include conducting daily calibration drift assessments, quarterly audits, and annual RATA.

Daily calibration drift assessments must be able to demonstrate that the results meet a set performance specification, otherwise the CEMS system will be out-of-control (OOC), resulting in invalid data and potential penalties if this is not remedied. Quarterly audits and annual RATAs also have their own specifications that, if not met, would result in the system being classed as OOC.

For quarterly audits, regulations require that these be spaced no less than 60 days apart and not be conducted for more than three consecutive quarters without a subsequent RATA to ensure compliance. The types of quarterly audits that can be conducted to fulfill this requirement include:

Cylinder Gas Audit (CGA)

• A CGA requires testing the entire CEMS system by introducing a zero gas and two upscale gas concentrations, each in triplicate succession. According to Section 5.1.3 of Procedure 7, the upscale gases used must include a mid-range gas, typically between 50-60 % of the calibration span, and a high-range gas, which should be between 80-100 % of the span.
• Average results of each triplicate injection must be ≤10 % of the span.

Dynamic Spiking Audit (DSA)

• The DSA is similar to the CGA but involves spiking the gas stream with known standards. In most cases, specialty equipment is required.
• To pass a DSA, the results need to be either less than 5 % of the span value at zero, mid, and high audit points or ≤ 20 % of applicable emission standard.

Relative Accuracy Audit (RAA)

• An RAA involves a stack testing firm visiting the site to perform an abbreviated version of the RATA. This audit requires at least three runs to be completed with the RA calculated similarly to the RATA testing described above.
• To successfully complete an RAA, the RA must be ≤ 20 % of Reference Method in the denominator.

In the past, a facility would be required to pay an additional contractor to complete these audits and provide quarterly reports.

Procedure 7 further mandates that each facility adhere to Above Span Calibration requirements. Specifically, if two consecutive hours yield average concentrations at a level 200 % or higher than the instrument's span, the facility must perform an above span calibration within 24 hours.

This necessitates ongoing monitoring of alarm thresholds and concentration averages, requiring facilities to have personnel trained to conduct these calibrations at any time, including weekends and holidays.

The RATA must be conducted annually. Facilities are required to notify the applicable administrator prior to conducting the test. It is also recommended that facilities with consistently low-level EtO concentrations seek alternative approval for using OTM-47 during the RATA to ensure a more accurate evaluation.

How Picarro Simplifies PS-19 Compliance

Commercial sterilizers play a key part in the US healthcare system by ensuring that lifesaving medical devices are safe for use by doctors and patients.

Picarro supports sterilizers by allowing them to concentrate on their core task—sterilization. Leveraging decades of experience, Picarro offers tools and managed services that simplify compliance with new CEMS regulations.

Picarro’s EtO systems are designed for seamless integration into any facility. Additionally, its Environmental Systems (ESYS) team is committed to providing support every step of the way. With thousands of systems successfully installed across all continents, Picarro is recognized for delivering the most accurate and reliable systems globally.

These systems feature a robust Data Acquisition System, expertly configured for straightforward reporting to the Electronic Reporting Tool (ERT). These systems are housed in a durable, portable cabinet that comes factory-equipped with automated Above Span Calibration checks, remote Cylinder Gas Audits, and remote access capabilities for specialized CEMS support.

Picarro’s environmental experts create all Quality Assurance documents to ensure compliance with federal regulations and operating permits while also assisting clients with their reporting requirements. Its team of trained field technicians provides all preventative maintenance and emergency support. Additionally, Picarro coordinates annual RATAs and engages with your Administrator to explain why OTM-47 is the optimal method for conducting your RATA.

The benefits of a Picarro system are vast, but the top three are:

1. Speedy response times. This allows for timeshare systems, saving overall costs as one analyzer can provide up to three measurement points.
2. Picarro solutions boast the lowest-in-class detection limit, eliminating the need to overreport emissions. Unlike other systems that may require up to 15 minutes to generate a low response, Picarro's results are generated on 2-second averages. This means that users receive the best data quickly and efficiently.
3. Picarro provides comprehensive end-to-end emissions monitoring solutions. Its team handles everything from start to finish, allowing clients to focus on what they do best— sterilization.

Acknowledgments

Produced from material originally authored by Sean Cronin, Project Manager at Picarro.

This information has been sourced, reviewed and adapted from materials provided by Picarro.

For more information on this source, please visit Picarro.