--- title: "When Do You Need New Biocompatibility Testing for a Medical Device?" description: "Learn when ISO 10993 biocompatibility testing is needed after a medical device change and when a risk-based justification is sufficient." featured_image: "https://patientguard.com/wp-content/uploads/2026/07/When-Do-You-Actually-Need-New-Biocompatibility-Testing.webp" url: "https://patientguard.com/when-do-you-need-biocompatibility-testing/" date_modified: "2026-08-02T15:16:16+00:00" --- **Published:** 27th July 2026 **Reviewed by:** David Small BSc (Hons), MSc, MTOPRA (Founder and CEO) ## When Do You Need New Biocompatibility Testing for a Medical Device? Manufacturers frequently modify their medical devices throughout the product lifecycle. A supplier may change a raw material, production may transfer to a different manufacturing site, a sterilisation method may be updated, or a design improvement may introduce new components. One of the first questions that follows these changes is whether new ISO 10993 biocompatibility testing is required. The answer is not always. A common misconception is that every material or manufacturing change automatically requires a complete programme of biological testing. In reality, ISO 10993-1 promotes a risk-based biological evaluation process in which existing evidence is reviewed before deciding whether additional testing is necessary. In many cases, manufacturers can demonstrate continued biological safety through documented scientific evidence, chemical characterisation, toxicological risk assessment and a robust Biological Evaluation Report ([BER](https://patientguard.com/services/regulatory-affairs/regulatory-glossary/)), avoiding unnecessary laboratory testing while remaining fully compliant with regulatory requirements. Understanding when existing biological evidence remains valid—and when new testing becomes essential—is critical for maintaining compliance with Regulation (EU) 2017/745 ([EU MDR](https://patientguard.com/services/regulatory-affairs/regulatory-glossary/)), UK MDR 2002 and [FDA](https://patientguard.com/services/regulatory-affairs/regulatory-glossary/) expectations. An inappropriate decision can result in unnecessary costs and project delays, while insufficient justification may lead to major non-conformities during a Notified Body audit or regulatory submission. This article explains how manufacturers should assess device changes, update their Biological Evaluation Plan ([BEP](https://patientguard.com/services/regulatory-affairs/regulatory-glossary/)), determine whether existing evidence can be leveraged, and identify the situations where additional ISO 10993 biocompatibility testing is genuinely required. [DISCUSS WITH THE EXPERTS](https://patientguard.com/contact-us/) 📘 ##### New to Medical Device Biological Evaluation? If you're looking for a complete introduction to biological evaluation under ISO 10993 and the EU MDR, including Biological Evaluation Plans (BEPs), Biological Evaluation Reports (BERs), chemical characterisation, toxicological risk assessment, biocompatibility testing and regulatory expectations, explore our [Complete Guide to Medical Device Biological Evaluation](https://patientguard.com/biological-evaluation-medical-devices/). --- ## Why Every Device Change Requires a Biological Evaluation Review Not every design or manufacturing change affects the biological safety of a medical device, but every change should trigger a documented review of the existing biological evaluation. ISO 10993-1 requires manufacturers to consider how modifications may influence the device’s interaction with the human body. Even relatively minor changes can alter the chemical composition of the finished device, introduce new manufacturing residues or affect the release of extractable and leachable substances. Conversely, many changes have no impact on patient exposure and can be justified without performing additional laboratory testing. Examples of changes that should initiate a biological evaluation review include: - Changes to raw material suppliers. - Material substitutions or formulation updates. - New coatings, adhesives or colourants. - Manufacturing process changes. - Manufacturing site transfers. - Changes to sterilisation methods. - New cleaning agents or processing chemicals. - Packaging or shelf-life changes that could affect the finished device. - Design modifications that alter patient contact. The purpose of the review is not to decide whether testing should automatically be repeated. Instead, it is to determine whether the existing biological evidence continues to demonstrate that the device remains biologically safe for its intended purpose. Many manufacturers mistakenly assume that repeating historical testing is always the safest regulatory option. However, both European and international standards increasingly encourage the use of scientific justification and existing evidence wherever appropriate. Repeating unnecessary testing can increase development costs, delay product launches and, in some cases, generate conflicting data that complicates regulatory submissions. The decision should therefore always be driven by risk, supported by documented scientific evidence, and recorded within the Biological Evaluation Plan before any testing strategy is finalised. --- ## The Biological Evaluation Plan Is the Starting Point Before deciding whether additional biocompatibility testing is required, manufacturers should update or create a Biological Evaluation Plan (BEP). Under ISO 10993-1, the BEP defines the strategy for assessing the biological safety of a medical device and provides the documented rationale for how compliance will be demonstrated. Rather than immediately sending samples for laboratory testing, the BEP establishes a structured approach for evaluating the impact of a device change. It considers the device’s intended purpose, the nature and duration of patient contact, the materials used, previous biological evidence, manufacturing processes and any new hazards introduced by the modification. A well-prepared BEP allows manufacturers to identify whether existing evidence remains applicable or whether additional information is required. In many cases, the review concludes that existing data is sufficient to demonstrate continued biological safety, eliminating the need for unnecessary testing. Typical questions addressed within a Biological Evaluation Plan include: - Has the intended purpose of the device changed? - Has the nature or duration of patient contact changed? - Have any new materials, additives, coatings or colourants been introduced? - Has the manufacturing process introduced new chemical residues or contaminants? - Has the sterilisation method changed? - Can existing biological, clinical or post-market evidence still be relied upon? - Is additional chemical characterisation or toxicological assessment required? - Does any remaining uncertainty justify further biological testing? Answering these questions provides the foundation for a risk-based biological evaluation strategy and ensures that any decision to perform—or not perform—additional testing is scientifically justified and fully documented. 📘 ##### Understanding ISO 10993-1:2025 This article explains when new biocompatibility testing may be required following a medical device change. For a detailed overview of the latest changes introduced in ISO 10993-1:2025, including updated biological evaluation principles, stronger alignment with ISO 14971, enhanced expectations for Biological Evaluation Plans (BEPs) and Reports (BERs), and the increasing emphasis on risk-based decision making, read our [Guide to ISO 10993-1:2025](https://patientguard.com/iso-10993-12025-whats-new-in-biological-evaluation-3/). --- ## ISO 10993-1 Promotes a Risk-Based Approach One of the most common misconceptions surrounding ISO 10993 is that every biological endpoint listed within the standard must be physically tested. In reality, ISO 10993-1 does not prescribe a fixed testing programme. Instead, it requires manufacturers to evaluate biological risks using a weight-of-evidence approach. This means that all relevant sources of information should be considered before deciding whether laboratory testing is necessary. Existing test reports, published scientific literature, chemical characterisation data, toxicological assessments, clinical experience and post-market surveillance can all contribute to demonstrating biological safety. The objective is not to perform the greatest number of tests, but to demonstrate that sufficient evidence exists to conclude that the device is safe for its intended clinical use. Where existing evidence fully addresses the biological risks associated with a device change, additional testing may provide little regulatory value. Conversely, where uncertainty remains or new hazards have been introduced, further laboratory testing may be the most appropriate method of reducing risk. By following this risk-based approach, manufacturers can focus resources on generating meaningful evidence rather than repeating testing that has already been adequately addressed through existing data. --- ![Infographic illustrating the ISO 10993-1 risk-based decision-making process for determining whether new biocompatibility testing is required following a medical device change. The workflow includes reviewing the Biological Evaluation Plan (BEP), assessing patient contact, evaluating materials and manufacturing changes, performing chemical characterisation and toxicological risk assessment, reviewing existing biological evidence, determining whether additional testing is required, and updating the Biological Evaluation Report (BER).](https://patientguard.com/wp-content/uploads/2026/07/ChatGPT-Image-Jul-23-2026-01_16_06-PM.png) --- ## When Can Existing Biological Evidence Be Leveraged? One of the key principles of ISO 10993-1 is that manufacturers should make full use of existing biological evidence before considering additional laboratory testing. If a device change does not introduce new biological hazards, existing evidence may continue to demonstrate that the device remains biologically safe. The decision should always be based on scientific justification rather than assumptions. Manufacturers must be able to demonstrate that the change has not altered the device’s biological risk profile and that any existing evidence remains applicable to the modified device. The following situations commonly allow manufacturers to leverage existing evidence instead of repeating biocompatibility testing. ### Material Equivalence Can Eliminate the Need for Repeat Testing Changing the supplier of a raw material does not automatically require new biological testing. If the replacement material is chemically equivalent to the original, manufacturers may be able to demonstrate that the biological safety profile remains unchanged. Chemical characterisation performed in accordance with ISO 10993-18 can compare the composition of the original and replacement materials, identifying any differences in additives, impurities or extractable substances. Where the materials are shown to be equivalent and no new toxicological concerns are identified, existing biological evidence may remain valid. However, supplier declarations alone are rarely sufficient. Manufacturers should support claims of equivalence with objective scientific evidence and document the assessment within the Biological Evaluation Report. ### Changes That Do Not Affect Patient Contact Many engineering changes have no impact on the surfaces or materials that come into contact with the patient. Examples include: - Updating internal electronic components. - Modifying software or firmware. - Changing enclosed mechanical parts. - Relocating components that remain isolated from patient contact. - Altering external packaging where the sterile barrier and device remain unaffected. Provided these changes cannot reasonably affect patient exposure to biological hazards, additional biocompatibility testing is unlikely to be necessary. Instead, manufacturers should document why the modification does not influence the biological evaluation and retain this justification within the technical documentation. ### Existing Clinical and Post-Market Evidence Supports Continued Safety Historical clinical use can provide valuable evidence that a device remains biologically safe following certain modifications. Where a device has an established history of safe clinical use, supported by post-market surveillance (PMS), complaint data and vigilance reporting, manufacturers may be able to rely on this information alongside chemical characterisation and toxicological assessment. For example, a manufacturing process improvement may not require repeat biological testing if it can be demonstrated that: - the finished device remains chemically equivalent; - no new manufacturing residues have been introduced; - patient exposure has not changed; and - existing clinical and post-market evidence continues to demonstrate an acceptable safety profile. Using multiple sources of evidence in this way reflects the weight-of-evidence approach promoted throughout ISO 10993-1 and helps manufacturers avoid unnecessary testing while maintaining regulatory compliance. 🧪 ##### Understanding Extractables & Leachables Testing Chemical characterisation plays a central role in determining whether new biocompatibility testing is required following a medical device change. To learn how extractables and leachables are identified, assessed and used to support biological evaluations under ISO 10993-18, read our [Guide to Extractables & Leachables Testing for Medical Devices](https://patientguard.com/extractables-and-leachables-testing-for-medical-devices-in-iso-10993/). --- ## When Is New Biocompatibility Testing Required? Although many device changes can be justified using existing biological evidence, there are situations where additional biocompatibility testing is likely to be necessary. The deciding factor is whether the change introduces new biological hazards or increases uncertainty regarding patient safety. If a modification has the potential to alter patient exposure, introduce new chemicals or affect the biological characteristics of the finished device, manufacturers should assume that further assessment will be required. Depending on the nature of the change, this may involve additional chemical characterisation, toxicological assessment, in vitro testing or, where scientifically justified, further biological studies. The table below outlines common examples. | Device Change | Is New Testing Likely? | Why? | | --- | --- | --- | | Introduction of a new polymer or material | High | New materials may introduce different chemical constituents, impurities or degradation products that require biological assessment. | | New coating, colourant or surface treatment | High | Surface modifications directly affect patient contact and may alter biological interactions. | | Change in patient contact type or duration | High | Increased or different patient exposure changes the biological endpoints that must be evaluated under ISO 10993-1. | | New sterilisation method | Moderate to High | Sterilisation can alter material properties and generate new extractable or degradation products. | | New manufacturing chemicals or cleaning agents | Moderate to High | Residual processing chemicals may introduce cytotoxicity or systemic toxicity risks if not adequately controlled. | | Manufacturing transfer with validated equivalent processes | Low to Moderate | Testing may not be required if manufacturing equivalence and product consistency can be demonstrated. | | Change of material supplier with demonstrated chemical equivalence | Low | Existing evidence may remain applicable when equivalence has been scientifically demonstrated. | | Software-only update | Very Low | Software changes generally have no impact on biological safety unless they alter patient-contacting components or device function affecting biological exposure. | It is important to remember that these examples are intended as general guidance rather than fixed regulatory rules. Every device should be assessed individually, taking into account its intended purpose, patient contact, constituent materials, manufacturing processes and available biological evidence. Ultimately, the decision to perform additional testing should always be supported by a documented scientific rationale within the Biological Evaluation Plan (BEP) and reflected in the updated Biological Evaluation Report (BER). --- ## A Risk-Based Decision-Making Process Determining whether new biocompatibility testing is required should follow a structured, evidence-based process rather than relying on assumptions or previous practice. ISO 10993-1 encourages manufacturers to assess each device change systematically, considering the potential impact on biological safety before deciding whether additional testing is necessary. In most cases, the assessment follows a series of logical steps that build upon one another. If sufficient evidence exists at any stage to demonstrate continued biological safety, further laboratory testing may not be required. Where uncertainty remains, additional investigations should be performed to address the remaining risks. A typical risk-based decision-making process includes: 1. **Identify the proposed change.** Clearly define the modification, including any changes to materials, manufacturing processes, sterilisation, suppliers, design or intended use. 2. **Review the existing Biological Evaluation Plan (BEP).** Determine whether the current evaluation strategy remains appropriate or whether it requires updating to reflect the proposed change. 3. **Assess patient contact.** Confirm whether the nature, duration or location of patient contact has changed, as this may alter the biological endpoints that require evaluation. 4. **Review materials and manufacturing processes.** Identify any new materials, additives, coatings, processing chemicals or manufacturing residues that could affect biological safety. 5. **Perform chemical characterisation where appropriate.** Compare the chemical composition of the modified device with the existing version in accordance with ISO 10993-18 to identify any new or increased chemical constituents. 6. **Complete a toxicological risk assessment.** Evaluate whether any identified chemicals present an unacceptable risk to patients using the principles described in ISO 10993-17. 7. **Review existing evidence.** Consider previous biological testing, clinical data, published literature, complaint history and post-market surveillance to determine whether sufficient evidence already exists. 8. **Determine whether uncertainty remains.** If the available evidence fully addresses the biological risks introduced by the change, additional testing may not be necessary. Where significant uncertainty remains, further laboratory testing should be planned. 9. **Update the Biological Evaluation Report (BER).** Record the assessment, supporting evidence, conclusions and justification so that the rationale is fully documented within the technical documentation. Following this structured approach helps ensure that biological evaluations remain scientifically robust, proportionate to the level of risk and aligned with current regulatory expectations. It also provides clear traceability for Notified Bodies, regulatory authorities and internal quality management processes, demonstrating that decisions regarding biocompatibility testing have been made using objective scientific evidence rather than assumptions. --- ## The Three Pillars of an Evidence-Based Biological Evaluation Where additional laboratory testing is not considered necessary, manufacturers must still demonstrate that the modified device remains biologically safe. This conclusion should never be based on opinion or previous experience alone. Instead, it should be supported by a structured evaluation of scientific evidence. An evidence-based biological evaluation combines chemical, toxicological and biological information to demonstrate that any changes made to the device do not introduce unacceptable risks to patients or users. The strongest justifications are built upon three complementary assessments. | Evaluation Pillar | Relevant Standard | Purpose | | --- | --- | --- | | Chemical Characterisation | ISO 10993-18 | Identifies and characterises the chemical constituents of the finished device, including extractables, leachables and potential degradation products, to determine whether the modified device remains chemically equivalent or introduces new substances of concern. | | Toxicological Risk Assessment | ISO 10993-17 | Evaluates any identified chemicals to determine whether patient exposure remains within acceptable safety limits and whether any toxicological risks require additional investigation or testing. | | Biological Evaluation Report (BER) | ISO 10993-1 | Brings together all available biological evidence, including chemical characterisation, toxicological assessment, historical testing, clinical data and post-market evidence, to determine whether the device continues to meet its biological safety requirements. | ************************ Each of these assessments contributes a different piece of the overall biological safety evaluation. Chemical characterisation identifies what substances may be present, toxicological assessment determines whether those substances present an acceptable level of risk, and the Biological Evaluation Report integrates all available evidence into a documented regulatory conclusion. By following this structured approach, manufacturers can demonstrate that decisions regarding biocompatibility testing are based on objective scientific evidence rather than assumptions. Where the available evidence adequately addresses all identified biological risks, additional laboratory testing may provide little regulatory benefit. Conversely, if uncertainty remains after these evaluations have been completed, further biological testing may be the most appropriate means of demonstrating device safety. This evidence-based methodology reflects the principles established within ISO 10993-1 and supports a proportionate, risk-based approach to biological evaluation throughout the medical device lifecycle. 🧫 ##### Understanding Cytotoxicity Testing Where additional biological testing is required, cytotoxicity testing is often one of the first biological endpoints assessed under ISO 10993-5. Learn how cytotoxicity testing evaluates the potential of medical device materials to damage or kill cells, when it is required, and how the results support a robust Biological Evaluation Report (BER) by reading our [Guide to Cytotoxicity Testing in Medical Device Biological Evaluation](https://patientguard.com/cytotoxicity-testing-in-medical-device-biological-evaluation/). --- ![Infographic illustrating the three pillars of an evidence-based biological evaluation for medical devices in accordance with ISO 10993-1. The diagram shows how chemical characterisation under ISO 10993-18, toxicological risk assessment under ISO 10993-17 and the Biological Evaluation Report (BER) work together to determine whether existing biological evidence is sufficient or whether additional biocompatibility testing is required following a medical device change.](https://patientguard.com/wp-content/uploads/2026/07/ChatGPT-Image-Jul-23-2026-01_19_14-PM.png) --- ## Common Mistakes When Assessing Device Changes One of the biggest challenges in biological evaluation is not performing the assessment itself, but knowing how much evidence is required following a device change. Manufacturers often fall into one of two extremes: either repeating unnecessary testing that increases costs and delays product launches, or assuming that no further assessment is required without sufficient scientific justification. Avoiding the following common mistakes can help ensure that your biological evaluation remains compliant with ISO 10993 and meets the expectations of Notified Bodies and regulatory authorities. ### Assuming Every Change Requires Repeat Testing Perhaps the most common misconception is that every material, supplier or manufacturing change automatically triggers a full programme of new biocompatibility testing. ISO 10993-1 does not require manufacturers to repeat testing simply because a change has occurred. Instead, it requires a documented assessment of whether the existing biological evidence remains applicable. Where sufficient scientific evidence already exists, additional laboratory testing may provide little value and unnecessarily increase development costs and timelines. ### Failing to Assess the Impact of Material Changes Not all material changes are equal. A minor formulation adjustment, a new colourant or a different processing aid may introduce new chemical constituents that affect biological safety, even if the primary material appears unchanged. Manufacturers should assess every material change using appropriate chemical characterisation and toxicological evaluation rather than relying solely on supplier declarations or material specifications. ISO 10993-1 does not require manufacturers to repeat testing simply because a change has occurred. Instead, it requires a documented assessment of whether the existing biological evidence remains applicable. Where sufficient scientific evidence already exists, additional laboratory testing may provide little value and unnecessarily increase development costs and timelines. ### Overlooking Manufacturing Residues Changes to manufacturing processes can introduce new cleaning agents, lubricants, mould-release agents or other processing chemicals that remain on the finished device. Even where the device design itself has not changed, these residual substances may alter the biological risk profile and should be considered as part of the biological evaluation. Appropriate process validation and chemical characterisation can help demonstrate that residual levels remain within acceptable limits. ### Ignoring the Impact of Sterilisation Changes Changing from one sterilisation method to another can significantly affect the chemistry of a medical device. Processes such as ethylene oxide (EtO), gamma irradiation, electron beam and steam sterilisation may alter polymer structures, generate degradation products or influence the release of extractable and leachable substances. These changes should always be assessed as part of the updated Biological Evaluation Plan. Even where the device design itself has not changed, these residual substances may alter the biological risk profile and should be considered as part of the biological evaluation. Appropriate process validation and chemical characterisation can help demonstrate that residual levels remain within acceptable limits. ### Failing to Update the Biological Evaluation Documentation A common finding during regulatory audits is that manufacturers implement design or manufacturing changes but fail to update the associated Biological Evaluation Plan (BEP) and Biological Evaluation Report (BER). Even if additional testing is not required, the rationale for that decision should be fully documented. Regulators expect to see clear evidence that each change has been assessed, the available scientific evidence reviewed and an appropriate conclusion reached using a risk-based approach. Maintaining complete and up-to-date biological evaluation documentation not only supports regulatory compliance but also demonstrates that biological safety continues to be actively managed throughout the entire medical device lifecycle. 🩹 ##### Understanding In Vitro Skin Irritation Testing If your biological evaluation identifies skin irritation as a relevant biological endpoint, manufacturers may need to perform testing in accordance with ISO 10993-23. Learn how reconstructed human epidermis (RHE) models are used to assess irritation potential, when testing is required, and how the results support a compliant Biological Evaluation Report (BER) in our [Guide to In Vitro Skin Irritation Testing](https://patientguard.com/in-vitro-skin-irritation-testing-iso-10993-23-standard/). ⚠️ ##### Biological Evaluation Starts with Risk Management Every biological evaluation should be driven by a robust risk management process. Learn how ISO 14971 helps manufacturers identify biological hazards, assess patient risks, implement effective risk controls and maintain compliance throughout the medical device lifecycle by reading our [Guide to ISO 14971 Risk Management](https://patientguard.com/understanding-iso-14971-ensuring-medical-device-safety-and-compliance-with-patient-guard/). --- ## How Patient Guard Can Help Determining whether new biocompatibility testing is required is rarely straightforward. A single material substitution, manufacturing change or supplier update can have significant implications for a device’s biological evaluation, yet unnecessary testing can add considerable cost, delay product launches and consume valuable development resources. At Patient Guard, we help medical device manufacturers make scientifically justified, risk-based decisions that align with ISO 10993, the EU MDR, UK MDR and FDA expectations. Our biological evaluation specialists review proposed device changes, assess existing biological evidence and identify whether additional laboratory testing is genuinely required or whether compliance can be demonstrated through existing data. Our biological evaluation services include: - Preparation and review of Biological Evaluation Plans (BEPs). - Biological Evaluation Reports (BERs) in accordance with ISO 10993-1. - Chemical characterisation strategies under ISO 10993-18. - Toxicological risk assessments in accordance with ISO 10993-17. - Gap assessments of existing biological evaluation documentation. - Biological evaluation support for design changes and manufacturing transfers. - Regulatory support for EU MDR, UK MDR and FDA submissions. - Ongoing biological evaluation updates throughout the product lifecycle. Whether you are introducing a new material, changing suppliers, transferring production or responding to Notified Body questions, our consultants can help you determine the most appropriate biological evaluation strategy while ensuring your technical documentation remains compliant and audit ready. --- ## Ready to Review Your Device Changes? If you are unsure whether a proposed change requires new biocompatibility testing, our biological evaluation specialists can help. We will assess your device, review the available evidence and recommend the most appropriate regulatory strategy, helping you avoid unnecessary testing while maintaining compliance with ISO 10993 and applicable regulatory requirements. [Contact Patient Guard today to discuss your Biological Evaluation Plan (BEP), Biological Evaluation Report (BER) or wider ISO 10993 compliance requirements.](https://patientguard.com/contact-us/) --- [Video](https://youtu.be/GlQQ2i1tCh0) --- ## Frequently Asked Questions About Biological Evaluation Do all medical device changes require new biocompatibility testing? No. Not every design, material or manufacturing change requires additional biocompatibility testing. ISO 10993-1 promotes a risk-based approach, requiring manufacturers to assess whether a change affects the device's biological safety. If existing evidence remains applicable and no new biological risks are introduced, additional testing may not be necessary. Can I change a material supplier without repeating ISO 10993 testing? Potentially, yes. A supplier change does not automatically require repeat testing if you can demonstrate that the replacement material is chemically equivalent to the original. Manufacturers should support this conclusion with appropriate chemical characterisation, toxicological assessment and documented justification within the Biological Evaluation Report (BER). What is a Biological Evaluation Plan (BEP)? A Biological Evaluation Plan (BEP) is the document that defines how the biological safety of a medical device will be assessed. It identifies the relevant biological endpoints, reviews existing evidence, considers device changes and establishes whether additional testing or assessments are required in accordance with ISO 10993-1. What is a Biological Evaluation Report (BER)? A Biological Evaluation Report (BER) documents the outcome of the biological evaluation process. It reviews all available biological evidence, including previous testing, chemical characterisation, toxicological risk assessments, clinical data and post-market information, before concluding whether the device remains biologically safe for its intended purpose. When is chemical characterisation used instead of biological testing? Chemical characterisation, performed in accordance with ISO 10993-18, is often used to evaluate material changes before considering additional biological testing. If the chemical profile demonstrates equivalence and no new toxicological concerns are identified, it may provide sufficient evidence to support the biological evaluation without repeating laboratory tests. Does changing the sterilisation method affect the biological evaluation? Yes. A change in sterilisation method can alter material properties, generate degradation products or influence the release of extractable and leachable substances. Manufacturers should assess the biological impact of any sterilisation change as part of the updated Biological Evaluation Plan and determine whether additional testing is required. Can post-market surveillance data support a biological evaluation? Yes. Complaint data, vigilance reports, published clinical evidence and post-market surveillance (PMS) information can all contribute to the weight of evidence supporting a biological evaluation. When combined with other scientific evidence, these data may help demonstrate that a device continues to meet its biological safety requirements. What happens if a Notified Body disagrees with my biological evaluation? If a Notified Body concludes that the available evidence does not adequately demonstrate biological safety, it may request additional justification or require further testing before conformity assessment can continue. A well-documented Biological Evaluation Plan, supported by chemical characterisation and toxicological assessment, can significantly reduce the likelihood of these findings. How often should a Biological Evaluation Report be updated? A Biological Evaluation Report should be reviewed whenever significant changes are made to the device, its materials, manufacturing processes or intended use. It should also be updated when new biological evidence, post-market surveillance data or relevant scientific information becomes available that could affect the device's biological safety. How can Patient Guard help with biological evaluations? Patient Guard supports manufacturers throughout the biological evaluation process by preparing and reviewing Biological Evaluation Plans (BEPs), Biological Evaluation Reports (BERs), chemical characterisation strategies and toxicological risk assessments. We help manufacturers determine whether additional testing is required and ensure biological evaluation documentation complies with ISO 10993, the EU MDR, UK MDR and FDA expectations. --- ## References This guide is based on the following legislation, international standards and official regulatory guidance relating to biological evaluation and biocompatibility testing of medical devices. | Organisation | Reference | Why it's relevant | | --- | --- | --- | | European Union | Regulation (EU) 2017/745 on Medical Devices (MDR) | Requires manufacturers to demonstrate that medical devices are safe and biologically compatible through compliance with the General Safety and Performance Requirements, including the identification, evaluation and control of biological risks throughout the device lifecycle. | | International Organization for Standardization (ISO) | ISO 10993-1:2025 – Biological Evaluation of Medical Devices – Part 1: Requirements and General Principles for the Evaluation of Biological Safety Within a Risk Management Process | Defines the internationally recognised framework for biological evaluation, helping manufacturers determine whether biocompatibility testing is required based on the nature, duration and type of body contact together with a documented biological risk assessment. The sixth edition introduces updated guidance on biological hazards, exposure duration, materials characterisation and alignment with ISO 14971. | | International Organization for Standardization (ISO) | ISO 14971:2019 – Medical Devices – Application of Risk Management to Medical Devices | Provides the internationally recognised risk management framework that underpins biological evaluation and supports decisions on whether existing evidence is sufficient or additional biocompatibility testing is required. | | U.S. Food and Drug Administration (FDA) | Basics of Biocompatibility: Information Needed for Assessment by the FDA | Explains the FDA's risk-based approach to biocompatibility assessment, including how intended use, materials, manufacturing processes, contact type and contact duration influence the need for biological evaluation and testing. | | U.S. Food and Drug Administration (FDA) | Biocompatibility Evaluation Endpoints by Device Category | Provides biological evaluation endpoint tables based on device category, body contact type and contact duration, illustrating how biological endpoints are selected using the principles of ISO 10993-1. | | International Organization for Standardization (ISO) | ISO 13485:2016 – Medical Devices – Quality Management Systems – Requirements for Regulatory Purposes | Defines the Quality Management System requirements that support biological evaluation through design controls, supplier management, material traceability, change control and post-market surveillance. | [](https://eur-lex.europa.eu/eli/reg/2017/745/oj)[](https://www.iso.org/standard/10993-1)[](https://www.iso.org/standard/72704.html)[](https://www.fda.gov/medical-devices/biocompatibility-assessment-resource-center/basics-biocompatibility-information-needed-assessment-fda)[](https://www.fda.gov/medical-devices/biocompatibility-assessment-resource-center/biocompatibility-evaluation-endpoints-device-category)[](https://www.iso.org/standard/59752.html) *Biological evaluation should always be based on a documented risk management process rather than automatically performing every biocompatibility test. Manufacturers should consult the latest published legislation, recognised standards and official regulatory guidance when determining the biological evidence required to demonstrate the safety of their medical devices.* --- David Small BSc (Hons), MSc, MTOPRA Reviewed byDavid Small, BSc (Hons), MSc, MTOPRAFounder & CEO |20+ years in medical device regulatory affairs,  MDR/IVDR compliance and quality systems. --- --- ## Patient Guards Recent Posts --- Cosmetic Product Safety Report (CPSR): A Complete Guide to UK Cosmetic Compliance August 31, 2026 No Comments Before a cosmetic product can legally be placed on the UK market, manufacturers and Responsible Persons must demonstrate that it is safe for human use under normal or reasonably foreseeable conditions. The Cosmetic Product Safety Report (CPSR) is one of the most important regulatory documents required under the UK Cosmetics Regulation. 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I highly recommend Patient Guard to any healthcare or MedTech organization looking for experienced regulatory and quality system partners for MHRA, ISO 13485, and broader medical device compliance initiatives. Thank you again to the entire Patient Guard team for being such reliable partners. Posted on Google Peter Reeve 80 days ago Trustindex verifies that the original source of the review is Google. STEPPER design, manufacture & distribute eyewear across the globe. With the increasingly complex landscape concerning the placing of Mecial Devices onto the market, we realised we needed professional guidance. We found Patient Guard via a simple internet search and are delighted we did! They provide a pragmatic solution to our needs, are totally reliable & always available to answer our (often simplistic) questions. They are highly efficient & responsive to what is a changing picture in our world and nothing is too much trouble. We have a much better understanding of regulatory affairs and our responsibilities as manufacturers & distributors and they support us in navigating the requirements in different territories. Updating our Declaration of Conformity, ensuring our labelling is compliant and acting as our PRRC are the key areas of their service for us. Posted on Google Derek Timm 80 days ago Trustindex verifies that the original source of the review is Google. For those companıes lookıng to comply to ISO standards and ın partıcular ISO13485 whıch to be honest ıs a nıghtmare I would strongly suggest goıng to the professıonals as ındeed we dıd by joınıng forces wıth Patıent Guard Ltd The staff are fantastıc nothıng ıs too much trouble and as a medıcal supply company we sımply cannot lıve wıthout them Thanks ın partıcular to Alex and Steve for all the hard work and our best regards from Dan Medıca South Lımıted Posted on Google BMSCriticalCare 117 days ago Trustindex verifies that the original source of the review is Google. Great service, very helpful and always willing to answer any questions we have, Posted on Google Thomson Software 788 days ago Trustindex verifies that the original source of the review is Google. Alex Lewis of PatientGuard guided us through the ISO13485 process in a thorough, systematic and efficient manner. He was friendly, patient and willing to go the extra mile. Excellent service. 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