The transition from ISO 10993-1:2018 to the 2025 revision represents a fundamental shift in how biological safety is defined, assessed, and justified for medical devices. While both versions position biological evaluation within a risk management process, the 2025 revision significantly deepens this integration and changes how manufacturers are expected to think about biological risks. From a regulatory perspective, this update signals a move away from checklist-driven compliance toward structured, defensible biological risk reasoning ‑ a fundamental evolution rather than a routine update.

Structural alignment with ISO 14971 sets the foundation

To understand the impact, it is helpful to start with the overall structure of the standard. ISO 10993-1:2018 is organized around device categorization and a matrix of biological endpoints that guides test selection. Although risk management is referenced, the structure still supports a linear, test-oriented workflow. In contrast, the 2025 revision is fully reorganized to align with ISO 14971. Biological evaluation is no longer a parallel activity but is embedded directly into the medical device risk management framework. This structural change establishes the foundation for all subsequent differences and signals higher expectations for traceability and justification.

Therefore, manufacturers who continue to manage biocompatibility as a standalone compliance activity, rather than as an extension of ISO 14971 risk management, are likely to face increasing challenges during conformity assessments under the revised standard.

Terminology shifts reinforce a hazard-based mindset

Building on this structural shift, the terminology used in the standard has also evolved. The 2018 version consistently refers to “biological endpoints,” a term closely associated with testing outcomes. The 2025 revision replaces this language with “biological effects,” which emphasizes potential harms rather than predefined tests. This change reinforces the idea that biological evaluation is about identifying and managing hazards, not merely performing tests. As a result, manufacturers must demonstrate that all relevant biological effects have been considered, even when testing is not performed.

In practice, notified bodies and regulators will be less interested in which tests were selected and increasingly focused on whether all relevant biological hazards were systematically identified and consciously addressed.

Device contact categorization becomes more precise

In parallel with the terminology changes, the approach to device contact categorization has been refined. The 2018 edition relies on broad categories such as surface-contacting, externally communicating, and implantable devices. The 2025 revision moves away from these rigid labels and instead focuses on the specific tissues and fluids contacted by the device or its components. For example, the term “externally communicating” is replaced by descriptions that reflect actual tissue contact, and “effects after implantation” is reframed as “local effects after tissue contact.” This change encourages more accurate hazard identification and discourages reliance on legacy classifications.

Exposure duration is to be calculated, not assumed

Closely connected to contact characterization is the treatment of exposure duration. In the 2018 version, exposure duration is grouped into general bands, with limited guidance on how to handle repeated or intermittent contact. The 2025 revision introduces explicit methods for calculating exposure duration, including cumulative exposure for daily or intermittent use. This change closes a long-standing gap and requires manufacturers to document how exposure duration is determined rather than relying on assumptions. Exposure duration will henceforth rapidly become a common point of regulatory scrutiny, particularly for reusable and intermittently used devices where legacy assumptions are often undocumented or scientifically weak.

Product characterization moves to the center of the evaluation

As exposure assessment becomes more rigorous, the importance of product characterization increases accordingly. In ISO 10993-1:2018, material and product characterization are required but largely supported through informative annexes. In the 2025 revision, these elements are integrated directly into the normative text. Material composition, manufacturing processes, and surface characteristics are treated as essential inputs to biological risk analysis. This shift reflects regulatory expectations that biological safety conclusions must be grounded in a deep understanding of the product itself.

Biological effects tables that support reasoning

The reworked biological effects tables further illustrate this evolution. The 2018 edition uses a single consolidated matrix in Annex A, which has often been applied as a checklist. The 2025 revision replaces this with four separate tables based on specific contact contexts, such as intact skin, mucosal membranes, damaged tissues, and circulating blood. This change encourages more targeted reasoning and reduces the risk of inappropriate or excessive testing, provided the manufacturer can justify the selected biological effects.

Legacy devices are explicitly brought into scope

The revised standard also addresses how existing devices should be handled. While the 2018 version introduces the concept of gap analysis, it provides limited guidance for legacy products. The 2025 revision explicitly discusses devices assessed under previous versions and clarifies that continued compliance must be justified through documented gap analysis. This ensures continuity while acknowledging that prior evaluations may not fully meet current expectations, emphasizing proactive lifecycle management rather than reliance on historical approvals.

Biological equivalence is formalized and scrutinized

In addition, the concept of biological equivalence is more clearly defined in the 2025 revision. What was previously an implicit and loosely applied concept is now supported by a dedicated section, diagrams, and clearer links to chemical characterization and exposure assessment.

This provides manufacturers with a clearer framework for equivalence arguments but also increases the level of evidence and justification expected by regulators and notified bodies.

Reporting expectations reflect a risk-based narrative

All of these changes converge in the expectations for documentation. Under ISO 10993-1:2018, biological evaluation reports often focused on test results and high-level conclusions. The 2025 revision places greater emphasis on documenting decision-making, hazard identification, uncertainty management, and risk acceptability. From a regulatory standpoint, biological evaluation reports are expected to read as coherent risk-based narratives rather than collections of test summaries. Biological evaluation reports that read as test catalogues rather than reasoned risk assessments will therefore become increasingly difficult to defend, even when the underlying test data are technically sound.

Strategic takeaway for manufacturers

In summary, ISO 10993-1:2025 transforms biological evaluation from a test-selection exercise into a structured biological risk management activity. Manufacturers who integrate biological evaluation into their ISO 14971 processes, strengthen material knowledge, and clearly document their reasoning will be best positioned to meet regulatory expectations. Those who continue to treat biocompatibility as a checklist exercise are likely to face increasing scrutiny under the revised standard.

If you are currently assessing how the ISO 10993-1:2025 revision affects your existing biological evaluations, we support targeted gap analyses and are happy to offer an initial 30-minute consultation to discuss your specific situation.

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Last updated 2026-01-30