Article by Medilink Member Chorley Consulting
Overview of the ISO 10993-1:2025 Revision
A revised version of ISO 10993-1 was published in November 2025 and replaces the 2018 version.
Here we hope to give some flavour of the changes introduced in the new version and our thoughts on what the impact may be for device manufacturers.
Key Changes in ISO 10993-1:2025
The main changes are listed in the document as follows:
- this document has been completely reorganised and the title has been aligned with the risk management framework described in ISO 14971;
- content has been added to provide guidance and clarification of calculation of exposure duration;
- content has been added to provide guidance on characterisation of the device and identification of biological hazards;
- the identification of biological effects (previously referred to as biological end points) has been modified;
- the term “externally communicating” has been replaced by language which reflects the specific tissue contact of device components;
- the term “effects after implantation” has been changed to “local effects after tissue contact” as some non-implanted devices also will need this type of assessment;
- Annex A has been revised to move most of the content to the main text and the remaining text in Annex A is now confined to the provision of guidance on materials characterisation;
- Annex B has been added to explain the rationale for the changes to biological effects listed in Table 1 to Table 4.
What the 2025 Changes Mean for Medical Device Manufacturers
The vast majority of the changes are editorial to better align with other standards and clarify some requirements. There are also some welcome changes which may nudge the science in the right direction, including strengthening the wording around minimising in vivo (animal) testing. It is now a clear requirement that the approach taken to reduce / replace / refine animal testing shall be justified and documented and that animal testing shall not be carried out under certain defined circumstances. We look forward to the authorities robustly applying these requirements.
Transition Timeline and Gap Analysis Considerations
No official transition period for implementation has been announced, but within the EU a 2-year transition timeline has been proposed. However, there is a responsibility of manufacturers to demonstrate they have the most scientifically appropriate and state-of-the-art risk assessment. The standard states that it “shall not be used to mandate re-testing of medical devices that are already on the market and have established and acceptable safety profiles” and gives guidance on devices evaluated using previous versions of the standard. It suggests a gap analysis process to establish if/what additional evaluation may be required.
This process can be summarised in the following flow chart:
The key thing about this kind of gap analysis is that it should be documented and the rationale for your decision making clearly laid out.
US FDA Recognition of ISO 10993-1:2025
Moving across the pond, the US FDA has recently announced a partial recognition of the standard. There are just two elements which are not recognised:
• Clause 6.9 (Biological risk estimation) is not recognised because it conflicts with clauses 5.5, 6, and 7 of the currently recognised ISO 14971:2019 risk management standard.
• The phrase “consumer products or” in Clause 6.5.11.3 is excluded because it conflicts with existing published FDA final guidance regarding low-risk intact skin contacting devices.
These have minimal impact on application of the standard, but you will need to make sure your evaluation captures the subtleties of the wording. The announcement acknowledges that technical reports to provide guidance on some of the more contentious elements of the new standard are still in development and, therefore, encourage manufacturers to contact them directly to discuss implementation of the standard before beginning biological evaluation. Additionally, US FDA have announced a transition period and that they will accept declarations of conformity to the 2018 edition until July 1, 2029. Because of this degree of uncertainty, if you know you will have a submission date to FDA before July 2029, then it would seem prudent to continue working with the 2018 version (in conjunction with the 2023 FDA guidance document[i]) but if you don’t have a clear submission timeline, then it would be advisable to start planning for 2025 version compliance.
Reasonably Foreseeable Misuse and Biological Risk Assessment
There has been much talk around the inclusion of consideration of “reasonably foreseeable misuse”. This does not mean that your biological evaluation needs to consider every possible misuse of the device. You only need to consider if there may be additional biological risks introduced if there is an established history of misuse of your device or similar types of device. The standard says (bold added to emphasise the relevant caveat) “Categorization of the medical device shall also consider the potential impact of reasonably foreseeable misuse in accordance with ISO 14971, where there is information available (e.g. post-market surveillance data, clinical literature) to suggest that the device can be used outside of its intended use, and this misuse is identified as being systematic”. When considering if this may impact your device, you should think about not only the data you hold on your specific device (e.g. PMS data) but also published clinical data on similar types of device in market. Conversely, it may be reasonable to utilise your own data to justify why reported examples of misuse of a similar device are not relevant to your device; e.g. because a certain design feature means your device could not be used in that way.
Final Thoughts on ISO 10993-1:2025 Compliance
In summary, whilst ISO 10993-1:2025 introduces some welcome changes and clarifies some points, it is not the seismic shift in thinking about the biological evaluation of medical devices that has been pushed about on social media. If you have been thoroughly evaluating your device and applying the previous version of the standard how it was intended to be applied, then you won’t be a mile away from complying with the new standard.
Stay calm, read and understand the standard, and then if you still have any concerns or questions, drop us an email:
[i] Use of International Standard ISO 10993-1, “Biological evaluation of medical devices – Part 1: Evaluation and testing within a risk management process” Guidance for Industry and Food and Drug Administration Staff September 2023.
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