QTS Scientists Sopheak Srun and Molly Swanson Discuss Sterilization Strategies with MPO Magazine

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Cretex Medical | QTS Scientists discuss the state of EO and gamma ray sterilization, and how medical device companies can find solutions that manage costs while ensuring patient safety.

May 21, 2025

Cretex Medical | QTS team members Sopheak Srun and Molly Swanson were interviewed for Medical Product Outsourcing (MPO) Magazine’s Medtech Makers Q&A series.

In this Q&A, Sopheak Srun, Principal Sterilization Scientist, and Molly Swanson, Senior Sterilization Scientist at Cretex Medical | QTS, discuss ethylene oxide (EO) sterilization and gamma ray sterilization technologies, as well as how QTS partners with companies to find the right solution for their needs.

What’s driving the discussion over medical device sterilization? Why are companies considering alternative methods? 

Sopheak Srun: Ongoing capacity constraints are the biggest issue in medical device sterilization. This is primarily driven by two factors: increased scrutiny of EO sterilization (which comprises approximately 50% of the sterilization market), and supply issues with the cobalt-60 (Co-60) used for gamma sterilization (which comprises ~40% of the sterilization market).

EO is highly effective for destroying microorganisms, but those properties also make excessive, inadequately controlled emissions from EO facilities carcinogenic. This has led to public protests, and the resulting pressure has caused a number of EO facilities to be shut down. This has put a strain on capacity.

Meanwhile, the processing capacity of gamma sterilization facilities has been limited. Those companies rely on Co-60, which can only be produced by a limited number of providers. Those organizations, in turn, do not have the capacity to accommodate the projected growth in the medical device industry.

The pressures on these two modalities, which perform ~90% of all medical device sterilization, are driving more and more companies to explore sterilization alternatives.

When determining the best sterilization method for a device, what are the most important factors a company must consider? What are the most relevant variables?  

Molly Swanson: At Cretex Medical | QTS, our team of on-site certified microbiologists and sterilization specialists work closely with customers to evaluate their sterilization needs to help them find solutions that manage costs while ensuring patient safety. There are several factors we consider. That includes material composition and its compatibility with each sterilization modality. The size and geometry of devices, if particularly large or complex, can limit the modalities used for sterilization. Additionally, there are other variables including time constraints, packaging considerations, available sterilization capacity given the anticipated production volumes, and logistical considerations. Which variables most impact decision making can vary by the unique needs of each device and customer. That’s why having a trusted partner with industry-leading expertise is vital for medical device manufacturers considering their sterilization options.

Given capacity, technology, cost, etc., how are you advising customers on their choice of sterilization? 

Srun: One option we’ve found to be very helpful for our customers is QSTERILE®—our proprietary pre-validated EO cycle. While the traditional half-cycle overkill approach has historically often been used with a high concentration EO cycle and has been popular due to its high validation success rate, the high volume of EO used can be problematic with regard to emissions. QSTERILE, on the other hand, reduces EO emissions by using the cycle calculation approach combined with a low concentration EO cycle. That also helps to minimize cycle times, meaning less stress on EO facility capacity, all while ensuring a safe and sterilized product.

With QSTERILE, a performance qualification runs using representative dunnage in accordance with ISO 11135, meaning you only need to conduct product-specific testing to integrate your items into the cycle. This proprietary service can save you both time and money by eliminating the need for a full EO sterilization validation on your end.

Finding the Right Sterilization Solution for You 

With capacity strain rising, cost and sustainability concerns, and emerging sterilization methods, finding the right validation solution can be daunting. QTS is here to help develop a sterilization strategy that best meets your needs. We’ll help you find a solution that creates the most efficiencies while best supporting patient outcomes.

To read the full article, visit ODT Magazine.

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