Lisa, we’ve got something new with ISO 11137-1. Let’s dive straight in. What are the main updates in the 2025 revision compared to the previous version?
The 2025 version introduces several changes but to me the most important one seems to be the updated normative references. ISO 11137-1 now references ISO 13004 and ISO/ASTM 52628, which is a big leap towards harmonisation, and here’s why I like it. First of all, the terminology has been updated to ASTM standards, which makes it a lot easier for manufacturers to understand the requirements. The updated terminology brings clarity, especially for manufacturers already familiar with ASTM-based standards. This should reduce interpretation issues and support a more consistent understanding of requirements across the industry.
Furthermore, ISO 13004 introduces 2.5 kGy increments for VDmax methods. Previously, only VDmax 15 and 25 were recognised. This update allows for more precise dose setting — and in specific cases, enables the use of lower radiation doses. The benefits? Improved material compatibility, greater process efficiency, and lower operational costs.
Last but not least, the limits for potential induced radioactivity assessment have been raised to 11 MeV for electrons and 7.5 MeV for X-rays. This is a welcome update, as higher beam energies mean better depth of penetration and enhanced throughput — again, improving process efficiency and product range.
That sounds like a considerable shift. What does this mean for small and medium-sized manufacturers?
Actually, I think this update works in their favour. Most of the changes are practical improvements that increase process efficiency and flexibility, simplify process design and compliance, and — in the long run — reduce overall product costs.
Rather than introducing more burdens, the revision seems to support smarter, leaner sterilisation strategies.
You were mentioning material compatibility and product range. Are there specific materials or products that require special caution during radiation sterilisation?
Yes, certain materials are particularly sensitive to radiation. Polymers like PTFE and some types of polyurethanes, as well as delicate electronic components, can degrade or lose functionality when exposed to high doses. These changes can affect not only the performance of the product but also its safety and shelf life.
In addition, products with thick or dense packaging, or those containing trapped air or moisture, may experience uneven dose distribution, which can compromise the effectiveness of the sterilisation process.
With the updated ISO 11137-1 now allowing a broader range of doses, there’s increased flexibility. This means a wider variety of products — even more sensitive or complex ones — can now be considered for radiation sterilisation, provided the dose is carefully selected and validated.
What about manufacturers considering a switch in their sterilisation process – for example, from ethylene oxide to radiation sterilisation? What should they keep in mind?
That’s a great question, because more and more manufacturers are indeed looking for alternatives to ethylene oxide — whether due to regulatory pressure, safety concerns, or sustainability goals.
Radiation sterilisation can be a very attractive option, but there are a few things to keep in mind. As mentioned earlier, not all materials respond well to radiation. You need to assess how each individual component reacts to the applied dose. Some materials may degrade, discolour, or lose their functional properties, which can impact product performance or safety.
Packaging plays a double role. On one hand, it acts as a physical barrier and can increase the dose needed to ensure sterility. On the other hand, packaging materials themselves may be sensitive to radiation, which can affect seal strength and/or sterile barrier integrity. Both sides need to be evaluated carefully.
Last but not least, some materials can produce toxic degradation products when exposed to radiation. This risk needs to be addressed as part of your biological risk assessment — especially if you’re using polymers or additives that are less well-characterised under irradiation.
Finally, are there any immediate actions that manufacturers should take in order to adapt to the 2025 version?
I think simplifying radiation sterilisation is really important, especially as the industry is gradually moving away from ethylene oxide. The updates in ISO 11137-1 are a step in the right direction — they make radiation sterilisation more accessible, flexible, and efficient.
That said, I believe these changes will have the biggest impact on new products and sterilisation setups. For existing, well-established processes, there might not be a strong need to make immediate changes — unless there’s a reason to optimise or revalidate. In that sense, the revision is more about opening up new possibilities rather than forcing companies to redo what already works.
Want to know more on this topic? Get in touch with Lisa via lisa.kamber@eumediq.eu!