ISO 10993 Contact Duration Matrix and Biological Endpoint Selection Explained
Affiliate Disclosure: Some links in this article are affiliate links. If you purchase through them, The Standards Navigator may earn a commission at no additional cost to you.
The Matrix Changed. If Your Biological Evaluation Plan Still Reads Like 2018, You Have a Gap
Table A.1 is gone. For seven years, biological evaluation plans were built around a single grid in Annex A of ISO 10993-1:2018 — cross-reference device category and contact duration, check the boxes, done. That table has been retired. ISO 10993-1:2025, published November 18, 2025, split it into four separate tables and rebuilt the exposure-duration logic underneath them.
ISO 10993-1:2025 is the international standard that guides biocompatibility and biological evaluation of medical devices using a risk-based framework, replacing the prescriptive checklist approach of the 2018 edition.
If your BEP still cites the 2018 ISO 10993 contact duration matrix, or if you categorized a reusable device’s contact duration based on a single use rather than total exposure period, you may already be carrying a documentation gap — one that surfaces exactly when a reviewer or notified body opens your file.
Regulatory affairs teams are asking a narrower question than “what is ISO 10993”: which biological endpoints does this specific device trigger under the current framework, and why. That’s what this guide walks through.
I’ve sat across the table from an auditor reviewing a biological evaluation plan where the contact duration category didn’t match the device’s actual use pattern — a reusable component that looked like “limited” contact on paper but was accumulating well past 24 hours across a single patient’s treatment course. The documentation existed. The categorization logic behind it didn’t hold up. That’s the gap this guide is built to close before it becomes a finding.
👉 Before you finalize your next biological evaluation plan, run it against a structured QMS gap check first. Get the free ISO 13485 Gap Assessment Checklist and confirm your documentation controls support the categorization decisions your BEP depends on.
In This Guide
- What changed in the ISO 10993-1:2025 evaluation matrix and why Table A.1 was retired
- The current contact duration categories and how “total exposure period” is calculated
- How to categorize daily contact, intermittent contact, and reusable devices correctly
- Which biological endpoints apply to each contact duration and body-contact combination
- What FDA’s partial recognition of ISO 10993-1:2025 means for your submission
- Common categorization mistakes that trigger additional testing requirements
- Where to buy the current standard and where to get ISO 13485-aligned training
Table of Contents
👉 Start Here (Top Resources)
- ISO 10993-1:2025 — ANSI Webstore — the current edition, direct from the accredited source. Use code CC2026 for 5% off. (Eric: insert the exact ANSI product link for ISO 10993-1:2025 here.)
- If you’re weighing whether to buy standards individually or as a set, the ANSI bundle option is worth checking before you purchase the 10993 series piece by piece.
- ISO 13485 Training — BSI Group — for teams building biological evaluation competency into a certified QMS.
- ISO Training Courses — ISOQAR — a second accredited training option worth comparing against BSI on schedule and price.
Why the Evaluation Matrix Was Restructured
Under ISO 10993-1:2018, Annex A Table A.1 organized devices by body contact category — surface, external communicating, implant — crossed with three contact duration bands, and listed an “X” for every biological endpoint a reviewer might expect to see addressed. Industry insiders came to call it the “Table A.1 mentality”: manufacturers treated the X’s as a mandatory checklist rather than a starting point for risk-based justification. Tests got run because they appeared in a cell, not because a documented risk assessment called for them.
ISO 10993-1:2025 splits that single table into four separate tables, each tied to a specific evaluation context, and embeds the framework more tightly into the ISO 14971 risk management process. The standard now expects a Biological Evaluation Plan built on the device’s actual risk profile — chemical characterization, materials history, intended use, contact pattern — with the tables used to check completeness, not generate a test order.
Most common finding: biological evaluation plans that cite “Table A.1” by name, or that list endpoints without a documented rationale tied to the device’s specific exposure profile. Under the current standard, that’s a gap a reviewer will flag.
If you are still building your first BEP for a device entering the medical device space, start with what the supplier controls requirements under ISO 13485 expect from your materials documentation — biological evaluation depends heavily on having reliable supplier and materials data before you ever get to a test matrix.
Contact Duration Categories, Defined
The three contact duration categories are unchanged in name but recalculated in practice:
| Category | Cumulative Contact | Typical Devices |
|---|---|---|
| Limited | Up to 24 hours total | Diagnostic swabs, single-use syringes, short procedural instruments |
| Prolonged | More than 24 hours, up to 30 days total | Wound dressings changed over several weeks, indwelling catheters (short-term), orthodontic devices |
| Long-term / Permanent | More than 30 days total | Implants, permanent orthopedic hardware, long-term catheters |
The category itself hasn’t moved. What changed is how you calculate “total contact” for a device that isn’t used in one continuous stretch — and that recalculation is where most categorization errors happen.
If you are evaluating a device used in short, repeated sessions → don’t categorize based on a single session length. The standard expects you to sum all contact time across the device’s full use pattern before assigning a category.
Daily Contact vs. Intermittent Contact
ISO 10993-1:2025 formalizes two exposure patterns that the 2018 edition handled inconsistently:
- Daily contact — the device touches the body every day, for any portion of a day, across a defined treatment course. Total exposure is counted as calendar days from first use to last use (or replacement) on a single patient.
- Intermittent contact — use with at least 24 hours between consecutive contacts. This is treated as repeated use of the same device, or a replacement device, under evaluation.
A wound contact layer changed daily over three weeks is the textbook example: under the 2018 edition, each dressing change might have been assessed as its own “limited” exposure. Under the current standard, the 21 cumulative contact days push the device into prolonged territory — and that shift can add endpoints your original evaluation never considered.
If you are re-evaluating a device that was cleared under the 2018 categorization logic → don’t assume your existing category still holds. Run the total exposure period calculation against the current definitions before you finalize anything for a new submission.
Reusable Devices and Total Exposure Period
Reusable devices are now categorized based on cumulative contact time for a single patient across the device’s full use pattern — not the duration of any one use, and not a multi-patient device service-life total. A reusable surgical instrument sterilized and reused across a procedure series looks brief per individual contact, but the relevant figure is how many total contact days that one patient accumulates across their treatment course, including reasonably foreseeable misuse such as use beyond the labeled reprocessing cycle count.
Bioaccumulation is a related but less settled consideration. FDA’s Supplementary Information Sheet for ISO 10993-1:2025 (Recognition No. 2-313) notes that ISO/TC 194 Working Group 1 is still developing technical reports specifically addressing bioaccumulation, intermittent contact, and reasonably foreseeable misuse. In practice: if chemical characterization data — extractables and leachables — raises a bioaccumulation concern, that finding should inform your risk assessment and may support escalating the device’s category, but document it as a risk-based judgment rather than treating it as a fixed clause requirement until the supporting technical reports are finalized.
For teams managing this inside a certified QMS, it’s a judgment call that needs to trace back to a documented decision — not a verbal risk call made in a meeting. Clause 9 of ISO 10993-1:2025 requires that biological evaluations be planned, conducted, and reported by competent personnel, with the evaluation report documenting the rationale behind risk decisions like this one. The CAPA requirements under ISO 13485 apply just as much to a categorization correction as to a nonconformance on the shop floor.
Mapping Contact Category to Biological Endpoints
The biological effects under consideration haven’t fundamentally changed — cytotoxicity, sensitization, irritation, systemic toxicity, genotoxicity, implantation effects, and hemocompatibility remain the backbone, and ISO 10993-1 remains a risk-based framework, not a mandatory testing checklist. What changed is the scope of consideration required, particularly for genotoxicity:
| Contact Duration | Body Contact | Genotoxicity Consideration |
|---|---|---|
| Limited | Any | Case-by-case, per risk assessment |
| Prolonged | All tissues except intact skin | Generally expected to be addressed per Tables 2–4 and Clause 6.5.7 |
| Long-term / Permanent | All tissues except intact skin | Generally expected to be addressed per Tables 2–4 and Clause 6.5.7 |
Under the 2018 edition, genotoxicity was consistently expected for implants and long-term tissue contact, but inconsistently applied to prolonged-contact devices touching mucosal membranes or breached surfaces. ISO 10993-1:2025 narrows that inconsistency: per Tables 2–4 and Clause 6.5.7, any device requiring systemic toxicity evaluation due to prolonged or long-term contact is now generally expected to address genotoxicity as well, intact skin excepted — though this remains a risk assessment expectation to be justified within your Biological Evaluation Plan, not an automatic in vivo test order. Where existing data (toxicological risk assessment under ISO 10993-17, chemical characterization, or literature) already addresses the risk adequately, testing may not be necessary. Carcinogenicity consideration was similarly extended for long-term contact with intact mucosal membranes.
Worth flagging directly: FDA’s Supplementary Information Sheet for ISO 10993-1:2025 (Recognition No. 2-313) identifies a genuine discrepancy here. ISO 10993-1:2025 lists genotoxicity as an endpoint for consideration across all prolonged-contact device categories, while FDA’s own Table A.1 (Attachment A of its 2023 Biocompatibility Guidance) limits the genotoxicity endpoint to implanted devices, externally communicating devices with tissue/bone/dentin contact, and externally communicating devices with circulating blood contact. For a U.S. submission, don’t assume the broader ISO scope automatically controls — confirm which framework your reviewer expects you to follow.
Most common finding: biological evaluation plans for prolonged-contact mucosal devices that address systemic toxicity but don’t document a genotoxicity rationale one way or the other — an omission that was easier to overlook under the 2018 matrix and is more likely to draw a question under the current one.
If your device’s evaluation also touches sterilization residuals, review our sterilization standards overview — ethylene oxide and other sterilization residues are a recurring driver of chemical characterization findings that reshape a biological evaluation.
FDA’s Partial Recognition — What’s Excluded
FDA recognized ISO 10993-1:2025 on May 25, 2026 (Recognition No. 2-313 in FDA’s Recognized Consensus Standards database), but the recognition is partial, not full. Two carve-outs from the Supplementary Information Sheet matter for submission strategy:
- The phrase “consumer products or” in Clause 6.5.11.3 (Low Risk Intact Skin Contacting Medical Devices) is not recognized — FDA states it conflicts with Attachment G of its 2023 biocompatibility guidance, which limits which historical-use materials qualify for reduced testing on skin-contacting devices.
- Clause 6.9, Biological risk estimation, is not recognized — FDA holds it conflicts with the risk estimation approach already established under ISO 14971:2019, which FDA separately recognizes.
If you are preparing a 510(k), PMA, or De Novo submission → you cannot submit a full Declaration of Conformity without addressing these two exclusions directly, and the genotoxicity discrepancy above is a separate, related point worth raising with your reviewer proactively. Cite the standard, but demonstrate compliance for the excluded clauses through FDA’s existing biocompatibility guidance rather than assuming automatic alignment. FDA’s recognized standard entry and Supplementary Information Sheet have already been updated since publication — verify the current version directly against FDA’s Recognized Consensus Standards database before finalizing any submission.
For the broader shift this represents in medical device documentation expectations, see our breakdown of validation and verification requirements under ISO 13485 and the FDA QMSR.
Common Categorization Mistakes
⚠️ Categorizing by single-use duration instead of cumulative single-patient exposure. The single most common error on reusable and repeat-use devices — it understates the contact category more often than it overstates it.
⚠️ Citing “Table A.1” in a current BEP. A reference to the old table structure is a documentation red flag on its own, independent of whether the underlying science holds up.
⚠️ Assuming genotoxicity doesn’t need to be addressed for prolonged mucosal contact. Teams working from older templates default to a 2018-era endpoint list and skip documenting a rationale either way — under the current tables, that gap is more likely to draw a question.
⚠️ Assuming FDA recognition is full, or that ISO and FDA genotoxicity scope match. Building a submission strategy around blanket alignment, without addressing the excluded clauses and the genotoxicity scope discrepancy, invites an avoidable deficiency letter.
If you are unsure whether existing biological evaluation plans need revisiting → they don’t automatically require retesting, but ISO 10993-1:2025 does expect a documented review confirming prior categorization and endpoint rationale still hold under current definitions.
Quick Audit Checklist
✅ Contact duration category calculated from cumulative single-patient exposure, not single-use duration
✅ Reusable/repeat-use devices assessed for total contact days for one patient across their treatment course
✅ Genotoxicity rationale documented for prolonged/long-term contact except intact skin, per Tables 2–4 and Clause 6.5.7
✅ Biological Evaluation Plan references current ISO 10993-1:2025 structure, not legacy Table A.1
✅ FDA submission strategy accounts for the two partially-recognized clauses and the genotoxicity scope discrepancy
✅ Bioaccumulation signals from chemical characterization data reviewed and documented as a risk judgment, not assumed to require automatic escalation ✅ Existing (pre-2025) biological evaluations documented as reviewed against current definitions
FAQ
Does ISO 10993-1:2025 require me to retest devices already on the market?
No. The standard doesn’t mandate automatic retesting for devices with an acceptable safety history. It does expect a documented review confirming prior categorization and evaluation still hold, and an update if a Clause 10 production change triggers a re-review.
Is ISO 10993-1:2018 still valid to use?
FDA’s recognized standards database is the authority for U.S. submissions — verify current recognition status before relying on either edition. For new evaluation plans, aligning with the 2025 edition is the safer long-term position.
What’s the difference between “prolonged” and “long-term” contact?
Prolonged contact covers cumulative contact exceeding 24 hours but not exceeding 30 days. Long-term (permanent) contact covers cumulative contact exceeding 30 days, driven by total exposure period rather than packaging or labeling.
Does the 2025 edition apply to devices regulated under the EU MDR?
It’s generally treated as state of the art for MDR purposes, but grace periods and notified body expectations vary — confirm directly with your notified body.
Is genotoxicity testing now mandatory for every prolonged-contact device?
Not automatically. Per Tables 2–4 and Clause 6.5.7, genotoxicity is generally expected to be addressed through risk assessment for prolonged and long-term contact with all tissues except intact skin — but “addressed” can mean justified through existing toxicological or chemical characterization data, not necessarily new in vivo testing. Note also that FDA’s own Table A.1 applies genotoxicity more narrowly than ISO does, so confirm which framework governs your specific submission.
Do I need a new Biological Evaluation Plan for every device?
No blanket requirement to start over. Most manufacturers can update an existing BEP to reflect current categorization logic and endpoint scope, provided the underlying risk assessment and chemical characterization data are still valid.
How does ISO 14971 relate to my biological evaluation?
ISO 10993-1:2025 is now more tightly embedded in the ISO 14971 risk management process. See our guide on risk management in medical devices under ISO 14971 for how that framework applies.
Where do I buy the current edition of ISO 10993-1?
Through an authorized reseller such as the ANSI Webstore, which also serves international buyers and offers standards in multiple languages. ISO 10993-1:2025 — ANSI Webstore — Coupon code CC2026 applies through December 31, 2026.
📥 Free Resources
- ISO 9001 Roadmap — step-by-step implementation guide for manufacturers building or improving a quality management system
- Manufacturing Compliance Checklist — practical compliance reference covering key ISO, OSHA, and quality requirements for production environments
- Supplier Quality Checklist — evaluation tool for assessing supplier quality controls and flow-down compliance before audits or new contracts
- ISO 13485 Gap Assessment Checklist — free checklist for medical device manufacturers assessing their QMS against ISO 13485 requirements
Not Sure What to Do Next?
🔹 Still researching how the current standard applies to your device? Read our Biocompatibility Standards Overview for the full picture before you build a test matrix.
🔹 Ready to build or update your Biological Evaluation Plan? Download the ISO 13485 Gap Assessment Checklist and confirm your documentation controls support the categorization decisions you’re about to make.
🔹 Need to purchase the current standard? ISO 10993-1:2025 — ANSI Webstore — code CC2026 takes 5% off, and international buyers can access the standard in multiple languages through the same source.
The Standard Changed. Your Categorization Logic Should Too.
Table A.1 was a shortcut, and shortcuts age out. ISO 10993-1:2025 asks for a defensible, risk-based answer instead of a checked box — and that’s a better position to defend in front of a reviewer regardless of which edition your notified body is citing this quarter. The Standards Navigator will keep tracking how FDA recognition and international adoption evolve as this transition plays out.
Don’t Let a Reviewer Find the Gap First
Most biological evaluation gaps don’t get caught in your own review — they get caught by a notified body auditor or an FDA reviewer, months after the plan was finalized. Manufacturers who treat contact duration categorization as a one-time exercise tend to carry that risk forward through every product change. Manufacturers who build a documented, repeatable categorization process into their QMS catch the drift before it becomes a submission delay.
The Standards Navigator tracks ISO 10993, ISO 13485, and the broader medical device compliance landscape as it evolves — including regulatory recognition changes like FDA’s partial recognition of ISO 10993-1:2025.
👉 Get updates on medical device biocompatibility and QMS requirements
👉 Be first to access new gap assessment tools and implementation resources
Subscribe below to stay ahead.
The Standards Navigator — Industrial Compliance. Clearly Explained.
