End of Life Exams Consistency throughout the entire reprocessing cycle

Single-step validations only confirm that each process step is effective for one cycle . In real-world applications, however, a medical device often undergoes dozens or even hundreds of reprocessing cycles. During these cycles, mechanical stress, thermal stress, chemicals, humidity, pressure fluctuations, and packaging processes cumulatively affect the product. Over time, this combination can lead to surface changes, material fatigue, loss of function, or reduced cleanability. End-of-life testing simulates this repeated exposure and answers the crucial question: "Will the product remain safe to use throughout its intended lifespan?"

The number of cycles is usually determined by the manufacturer's specifications, risk analyses, the intended use, and the expected reprocessing intervals. Some products are designed for 50 cycles, others for 150 or more. HygCen Germany does not assess how many cycles are appropriate but only tests the number specified by the manufacturer or operator. If no cycle count has been defined, we recommend consulting external regulatory advisors; as a testing laboratory, we do not establish service life strategies.

In practice, these are primarily:

• Corrosion or pitting
• Cracks or delaminations (e.g. in coatings)
• Material discoloration or embrittlement
• loose or blocking mechanisms
• increasing particle levels (AAMI TIR42)
• elevated TOC or residual protein levels after purification
• Reduced vapor penetration due to material deformation
• reduced barrier effect of packaging

HygCen Germany documents such findings neutrally and without interpretation regarding product lifespan or marketability. Assessments of risk or product design are carried out by external experts.

ASTM F1980 describes methods for accelerated aging based on thermal and humidity-related stresses. This method allows for a quick assessment of how materials will behave over extended storage periods. Combined with reprocessing cycles according to ISO 17665-1 and ISO 15883, this provides a comprehensive picture of thermal aging and cyclic stress. HygCen Germany conducts these aging processes neutrally and combines them with subsequent functional and cleanliness tests.

Yes, indirectly. End-of-life tests not only examine the product itself, but also demonstrate whether the underlying cleaning and sterilization processes remain reproducible over many cycles. If a product suddenly becomes harder to clean after many cycles, or exhibits unusual soiling or particle patterns, this does not necessarily indicate a material defect—it could be due to altered surfaces or functional characteristics. HygCen Germany only evaluates the test data; process analyses are conducted externally.

End-of-life exams form the bridge between:

• RDG validation (ISO 15883)
• Cleanliness validation (TOC/Protein/Hb/ISO19227)
• Sterilization validation (ISO 17665-1/13060/285)
• Packaging validation (ISO 11607-2)

They assess whether the product's function changes in the long term as a result of these repeated processes. Therefore, end-of-life is an essential element of technical documentation, risk analysis, and usability assessment.