6 Medical Device Reprocessing Validation Mistakes to Avoid in 2026

Introduction

Reusable medical devices sit right on the fault line between great engineering and messy reality. On paper, you have a product that can be cleaned, disinfected, sterilised, and reused safely. In the real world, you have blood, proteins, drying time, human behaviour, hospital variability, tight turnaround, and devices getting older with every cycle. 

That gap is exactly why regulators have tightened expectations. Under the EU MDR, the Instructions for Use (IFU) for a reusable device must describe the processes that allow safe reuse, including cleaning, disinfection, packaging, and (where appropriate) a validated method of re-sterilisation, and it must also tell users when the device should no longer be reused, for example due to material degradation or a maximum number of reuses. The FDA similarly expects manufacturers to provide scientifically validated reprocessing instructions and includes detailed expectations for what is reviewed in premarket submissions.  

What follows are the main technical and regulatory challenges that repeatedly cause delays, nonconformities, and avoidable cost. 

1. MDR Raised the Bar: “Reusable” Now Means “Proven Reusable”

The MDR doesn’t just want a credible story. It wants evidence that the IFU actually works in practice, across a realistic range of users, facilities, and worst-case device conditions. 

Two implications often catch teams out: 

• The IFU becomes a testable claim. If you state a method (manual brushing here, rinse for X seconds, disinfect for Y minutes, sterilise by Z cycle), you need validation that demonstrates it is effective and repeatable.  

• End-of-life is part of compliance. MDR explicitly expects you to define when the device must stop being reused (e.g., visible degradation, functional failure, or a stated maximum number of reuses).  

The practical challenge: many technical files still contain excellent design and risk documentation, but weak, fragmented reprocessing evidence, especially when cleaning is manual, the device has lumens/hinges, or the service life claim is ambitious. 

2. Cleaning Validation: The Hardest Step is the One Everyone Underestimates

Medical device cleaning is the foundation. If you don’t reliably remove soil, disinfection and sterilisation validations become far less meaningful, because they’re no longer being assessed on a realistically soiled device. 

Key challenges manufacturers run into: 

• Choosing the right “worst case” 

Cleaning validation lives and dies on worst-case selection: device geometry, materials, hardest-to-clean locations, and worst-case contamination and drying conditions. Standards and guidance emphasise robust development and validation of cleaning processes (including acceptance criteria and rationale).  

• Test soil and residues: proving “clean enough” 

Demonstrating cleaning efficacy isn’t simply “it looks clean”. Current approaches rely on measurable residues (e.g., protein, haemoglobin, carbohydrates, TOC, depending on method and device), and structured methods for demonstrating cleaning efficacy exist in standards used across the industry.  

• Manual cleaning variability 

Manual medical device cleaning is often the real bottleneck: user-to-user variation, brush selection, access limitations, and human factors. Even when the method is technically sound, it can be operationally unrealistic in a hospital setting, creating a mismatch between “validated” and “doable” (this is one reason manual cleaning IFUs are under increasing scrutiny).  

Bottom line: cleaning validation is not a formality. It is usually the most failure-prone part of the reprocessing chain, and it needs a disciplined rationale for soils, endpoints, and worst-case device selection.

3. Disinfection Validation: Efficacy is Only Half the Story

Disinfection validation sounds straightforward, apply disinfectant, achieve microbial reduction, but reusable device reality makes it complex. 

The hidden dependency: cleaning effectiveness 

Disinfection assumes a device is already clean enough for the disinfectant to contact surfaces effectively. Residual soil can shield microorganisms and reduce disinfection performance. That’s why FDA guidance treats reprocessing validation as an end-to-end scientific demonstration, not isolated steps.  

Internal surfaces, lumens, joints, porous interfaces 

Devices with lumens, textured surfaces, hinges, or multi-part assemblies introduce the classic disinfection problem: contact. It’s not enough for a disinfectant to be potent; it must reliably reach the hardest-to-access areas in real-world use. 

Material compatibility and repeated exposure 

Disinfectants can degrade plastics, adhesives, seals, coatings, and markings over time, especially when combined with heat, water quality variation, and repeated cycles. Disinfection validation therefore often overlaps with service-life and compatibility work (covered below). 

4. Sterilisation Validation: Selecting a Method is Easy – Defending it is Not

Medical device sterilisation validation is well-established, but reusable device programmes still fail for predictable reasons. 

Matching the sterilisation method to the device and the IFU 

Steam, ethylene oxide (EO), and radiation each have distinct requirements and constraints, and the relevant ISO standards set expectations for development, validation, and routine control.  

The challenge is rarely “how to sterilise”. It’s proving that: 

• the chosen method is compatible with the device materials and function, 
• the packaging and configuration are correct, 
• the worst-case load and presentation have been considered, and 
• the sterilisation instruction in the IFU is realistic for the intended user environment. 

“Validated method of re-sterilisation” is explicitly expected in MDR IFU content 

Under MDR, if the device is reusable, the IFU must include the appropriate processes for reuse and, where appropriate, the validated method of re-sterilisation.  

So, if the IFU says “steam sterilise at X”, you need a validation approach that makes that statement defensible. 

5. Service Life Validation and Material Compatibility: Proving the Device Survives its Own IFU

Service life is where many reusable devices stumble, because it forces you to test the device as it is actually used, not as it looked when it came off the production line. 

Reprocessing is accelerated ageing (whether you like it or not) 

Repeated cycles mean repeated exposure to detergents, disinfectants, heat, moisture, mechanical action, and handling. Over time, that can drive: 

• corrosion, stress cracking, embrittlement, 
• seal degradation and leakage, 
• joint loosening, loss of cutting performance, 
• coating wear, delamination, and changes in surface energy. 

A very practical MDR signal here is UDI durability expectations: for reusable devices that require cleaning/disinfection/sterilisation between uses, the UDI carrier must remain permanent and readable after each process throughout the intended lifetime (unless direct marking is not feasible or would interfere with safety/performance).  

Linking service life to “stop-use” criteria 

MDR expects IFU content that identifies when the device should no longer be reused, either by maximum cycles or signs of degradation.  

That means a service life claim is not just a marketing statement; it becomes a validated boundary of safe performance. And if your service life is “100 cycles”, you should expect to demonstrate that critical performance and safety characteristics still hold after simulated 100-cycle reprocessing.

6. Biocompatibility After Service Life: Yesterday’s Biological Evaluation May Not Reflect Today’s Device

A biological evaluation that only considers the “new” device can be a weak spot for reusable devices, because reprocessing can change the surface and the residual chemical profile. 

Biological evaluation is risk-based, and increasingly scrutinised 

ISO 10993-1 sets a risk-based framework for biological evaluation within a broader risk management process (linked to ISO 14971 principles), and regulators use this logic to challenge weak assumptions. The FDA also provides current guidance on the use of ISO 10993-1 in biocompatibility assessment.  

Sample preparation and extraction matter more after reprocessing 

ISO 10993-12 provides guidance on sample preparation and reference materials, critical when deciding what “representative” means for an aged, reprocessed device. 

The core challenge: you will need to justify that your biocompatibility assessment still holds after repeated cleaning/disinfection/sterilisation, because residues, surface chemistry, microcracking, and material changes can alter biological response. 

What Strong Reusable Validation Programmes Do Differently

Across MDR and FDA expectations, the best programmes tend to share the same discipline: 

1. Start with an IFU-first validation plan. Write (or stress-test) the medical device reprocessing instructions early, then validate what you actually intend to publish.  
2. Build a worst-case matrix. Hardest-to-clean features, most sensitive materials, maximum cycle count, and worst-case soil/drying. 
3. Treat cleaning + disinfection + sterilisation as a chain. Validate end-to-end performance, not isolated successes.  
4. Link service life to objective stop-use criteria. Maximum cycles, inspection points, and functional thresholds that can be taught and followed in the field.  
5. Revisit biological safety using an “aged device” mindset. Risk-based justification, representative samples, and defensible rationale for what changed (or didn’t) after reprocessing. 

Reusable devices are absolutely a sustainability and cost win, when reuse is real. The challenge today is that regulators are no longer willing to accept “reusable by design”. They want “reusable by evidence”.