ISO 10993: What Does Adhesive Biocompatibility Really Mean?

Key takeaways

• ISO 10993 addresses the biological evaluation of medical devices. It does not provide universal certification that an adhesive is safe for every form of human contact.
• The biological evaluation strategy depends on the device's intended purpose, the nature and duration of body contact, and the biological hazards identified.
• ISO 10993-1:2025 sets out requirements and general principles for biological safety evaluation within a risk management process aligned with ISO 14971.
• The corresponding Polish national adoption is PN-EN ISO 10993-1:2026-06.
• Testing an adhesive or an individual component does not automatically establish the biological safety of the finished medical device.
• Adhesive selection requires a review of the available test evidence, the material condition tested, curing conditions, manufacturing processes and the intended nature of body contact.
• An adhesive used to assemble medical device components is not automatically a tissue adhesive intended for wound closure.

What is ISO 10993, and what does adhesive biocompatibility mean?

ISO 10993 is a series of international standards addressing the biological evaluation of medical devices. It provides a framework for identifying and assessing potential biological risks arising from the interaction between a medical device, its constituent materials and the human body.

In this context, biocompatibility concerns the biological response to a material or device under defined conditions of use. It cannot be meaningfully assessed without considering how, where and for how long that material will be used.

For example, the same material may be considered for a component contacting intact skin or for a device with blood or internal tissue contact. The route and duration of exposure can change the biological safety questions that need to be addressed.

Why is the term "biocompatible" not sufficient on its own?

Suppose an adhesive manufacturer provides a cytotoxicity test report referring to ISO 10993-5. This is relevant technical evidence, but the result does not automatically answer questions about sensitisation, irritation or other biological hazards that may be associated with the intended medical device.

Neither does it establish that the adhesive is suitable for unlimited contact duration or for every type of medical device construction.

ISO 10993-1:2025: What changed in the latest edition?

The sixth edition of ISO 10993-1:2025 was published in November 2025 under the title "Biological evaluation of medical devices – Part 1: Requirements and general principles for the evaluation of biological safety within a risk management process".

The revised standard establishes requirements and general principles for evaluating biological safety as part of a risk management process aligned with ISO 14971.

According to the information published by ISO, the revision includes a reorganisation of the document, further clarification of exposure duration, greater emphasis on material characterisation and the identification of biological hazards, and updated terminology.

What does this mean for design and process engineers?

The key question is no longer simply whether a material has undergone certain tests. Engineers also need to determine whether the available evidence adequately addresses the biological risks arising from its use in a particular device.

This requires a clear understanding of material composition, processing conditions, potential exposure and manufacturing residues. Available data should then be reviewed to establish whether they are sufficient or whether additional evaluation is justified.

The publication of a revised standard does not automatically mean that every previously qualified material must undergo a complete new testing programme. The need for further assessment must be determined in the context of existing evidence, changes to the device, applicable requirements and the documented risk evaluation.

ISO, EN ISO and PN-EN ISO: How should these designations be interpreted?

Technical specifications and supplier documentation may refer to the same standard using different national or regional designations. The distinctions are important:

The Polish Committee for Standardization (PKN) identifies PN-EN ISO 10993-1:2026-06 as replacing PN-EN ISO 10993-1:2021-06 in the Polish standards catalogue.

Is ISO 10993-1:2025 harmonised under the EU Medical Device Regulation?

The reference to EN ISO 10993-1:2025 was published in the Official Journal of the European Union through Commission Implementing Decision (EU) 2026/1231 of 11 June 2026.

Under Article 8 of Regulation (EU) 2017/745, commonly known as the Medical Device Regulation (MDR), conformity with the relevant harmonised standards whose references have been published in the Official Journal can provide a presumption of conformity with the requirements covered by those standards or their relevant parts.

This does not automatically authorise an adhesive or a finished medical device to be placed on the market. The medical device manufacturer remains responsible for meeting all applicable regulatory requirements and demonstrating the conformity of the finished device.

Which parts of ISO 10993 may be relevant when selecting an adhesive?

The ISO 10993 series covers a range of subjects involved in biological safety evaluation. These include biological testing, chemical characterisation and toxicological risk assessment.

There is no single test package that automatically applies to every adhesive. The appropriate evaluation strategy depends on the finished device, its intended use and the biological hazards identified through risk assessment.

Important: the table highlights selected parts of the ISO 10993 series. It is not a mandatory testing checklist for every adhesive. The need for particular tests, or the justification for relying on existing evidence, should follow from the biological risk assessment of the specific device.

Why does adhesive biocompatibility testing not replace evaluation of the finished medical device?

An adhesive is one element of a manufacturing process. In the finished device, it may be present in a different condition from the material originally dispensed, including a fully or partially cured state, and may interact with other components.

The final characteristics of the device can also be influenced by surface preparation, cleaning, curing and sterilisation, where applicable.

Consequently, a biological test result obtained for a particular adhesive sample cannot automatically be treated as evidence of the biological safety of every finished device containing that adhesive.

US Food and Drug Administration (FDA) guidance on biocompatibility emphasises evaluation of devices in their final finished form, taking account of manufacturing processes, sterilisation and potential residues. This is useful technical guidance, although the regulatory requirements for placing medical devices on the EU market are determined by the relevant European legislation.

Which changes may affect the biological safety assessment?

• Changes to the adhesive formulation or constituent materials may alter chemical composition and the profile of potential hazards.
• Changes to curing conditions may affect residual substances and the characteristics of the cured adhesive.
• Changes in the nature of body contact may require a different biological evaluation.
• Changes in exposure duration may alter the nature of the biological risk being assessed.
• Changes to cleaning or sterilisation processes may affect the final characteristics of the device.

Not every change necessarily requires the complete testing programme to be repeated. However, its potential impact should be evaluated and appropriately documented within the risk management process.

How to select an adhesive for medical device component manufacturing

Adhesive selection should begin with the design, materials and manufacturing requirements of the medical device, rather than a general "medical grade" claim in a product catalogue.

Before making a selection, design engineers and process specialists should consider the following:

1. Intended purpose of the finished device. What function will the device perform, under what operating conditions, and which regulatory requirements apply to the project?
2. Nature of body contact. Will contact be direct or indirect? Which tissues or body fluids may be involved, and for how long?
3. Materials to be bonded. Which metals, polymers, glass or other substrates are involved? How will the bonding surfaces be prepared?
4. Dispensing and curing process. Is light curing required? Does the joint geometry allow the required curing conditions and process control?
5. Downstream processing. Will the assembly undergo cleaning, elevated temperatures, chemical exposure or sterilisation?
6. Manufacturer documentation. Which parts of ISO 10993 are covered by available studies? Which exact adhesive grade was tested, and in what condition?
7. Quality assurance. How will bond quality, process repeatability and compliance with the design requirements be verified?
8. Final device evaluation. How will supplier data be incorporated into the biological safety evaluation and technical documentation of the finished device?

Practical examples: LOCTITE AA 3922 and tesa 4965

Biological evaluation data may be available for different adhesive technologies. Such data are not limited to cyanoacrylate-based products.

LOCTITE AA 3922 – light-curing adhesive for medical device assembly

LOCTITE AA 3922 is an acrylic adhesive cured by ultraviolet or visible light. Henkel identifies applications including the bonding of stainless steel cannulae into assemblies used for needles, syringes and lancets.

The manufacturer positions the product for selected medical device assembly applications and provides information about biocompatibility testing in accordance with ISO 10993 within a defined scope.

This information should not be interpreted as unrestricted approval for wound closure or every form of body contact. The current manufacturer documentation and the requirements of the specific device must be reviewed.

An important distinction: LOCTITE AA 3922 is not a cyanoacrylate adhesive. It is a light-curing acrylic adhesive, illustrating that biological evaluation data may be relevant to several different bonding technologies.

tesa 4965 – an industrial mounting tape with documented skin-contact testing

tesa 4965 Original Next Gen is a double-sided industrial adhesive tape with a PET carrier and an acrylic adhesive system. The manufacturer provides information relating to skin-contact testing with reference to ISO 10993-5 and ISO 10993-10.

Such evidence may be relevant when assessing materials for a defined application. It does not make the tape a wound dressing, a tissue adhesive or a product intended to close wounds.

The scope of testing and the applicability of the supporting documents must be checked for the exact product version and intended use. Evidence relating to one formulation or product generation should not automatically be applied to every other variant.

tesa 4965 – selected variants available from Melkib

Medical device assembly adhesives versus tissue adhesives: What is the difference?

The expression "medical adhesive" can refer to products serving very different functions. Some are used to assemble device components, while others are finished medical devices specifically intended for contact with biological tissues.

The deciding factors are the intended purpose of the individual product and the evidence supporting its evaluation.

Why are industrial and medical cyanoacrylates not interchangeable?

Cyanoacrylates are a family of fast-curing adhesives widely used in technical assembly. Polymerisation of many cyanoacrylate formulations is initiated, among other factors, by moisture present on the bonding surfaces.

Depending on their chemical structure, cyanoacrylates include:

• MCA – methyl cyanoacrylates,
• ECA – ethyl cyanoacrylates,
• BCA – butyl cyanoacrylates,
• OCA – octyl cyanoacrylates.

Differences in molecular structure can affect material properties, polymerisation behaviour and biological interactions.

MCA and ECA – established industrial adhesive chemistries

Methyl and ethyl cyanoacrylates are well known in technical bonding applications. However, the use of these chemistries in industry does not make a conventional instant adhesive suitable for direct wound contact.

A comparative study published by Toriumi and colleagues in 1990 reported differences in tissue responses to selected cyanoacrylate formulations. Those findings should not be generalised to every modern adhesive within the same chemical family.

BCA and OCA – chemistries used in specialised tissue adhesives

Specific butyl and octyl cyanoacrylate formulations have been developed for use in specialised medical tissue adhesives. Clinical studies have included products based on 2-octylcyanoacrylate.

However, a product described as "butyl cyanoacrylate" or "octyl cyanoacrylate" should not automatically be considered suitable for wound closure. The formulation, manufacturing process, purity, application method, testing evidence and specified medical purpose all matter.

The Vietnam War and cyanoacrylates: A remarkable chapter in medical adhesive history

The medical use of cyanoacrylate adhesives has a history that extends well beyond today's wound closure products. Research and clinical use during the Vietnam War formed an important part of that development.

In battlefield medicine, controlling severe bleeding rapidly was a major challenge. Researchers investigated whether certain cyanoacrylate formulations could assist haemostasis – the process of stopping bleeding.

In 1969, Collins and colleagues published an account of the clinical use of cyanoacrylate adhesives as topical haemostatic aids in seven combat casualties. In 1970, Heisterkamp and colleagues described emergency use of N-butyl cyanoacrylate in cases involving injuries to solid organs in Vietnam.

These historical medical publications are among the sources behind the widely repeated story of cyanoacrylate adhesives being used in battlefield treatment.

Were soldiers' wounds really closed with "Super Glue"?

That popular description oversimplifies the evidence. Published reports concerned particular medical applications of cyanoacrylates, including assistance with bleeding control. They do not establish that conventional instant adhesives available today are suitable for closing wounds.

Historical and experimental medical uses also must not be confused with current product indications or compliance with modern regulatory requirements.

What did these early experiences teach researchers?

The development of tissue adhesives demonstrated that similar chemical compositions do not necessarily produce the same biological response. Tissue reactions, curing behaviour and the properties of the complete formulation are all relevant.

Further research contributed to specialised medical devices that should be clearly distinguished from industrial instant adhesives.

For modern design engineers, the lesson remains relevant: a bonding technology may offer significant potential, but responsible implementation depends on evaluating the specific material and its intended application.

How can ISO 10993 information support an informed purchasing decision?

When sourcing adhesives or tapes for medical device manufacturing, it is worth defining technical and documentation requirements before comparing products.

Three distinct levels of evidence should be considered:

1. Product-level information: adhesive properties, curing technology, substrate compatibility, processing requirements and available manufacturer documentation.
2. Biological testing information: tests performed, samples evaluated, test conditions and limitations of the findings.
3. Finished-device evaluation: risk management, process validation, technical documentation and compliance with applicable regulatory requirements.

This approach helps prevent a product from being selected solely because of a marketing claim that does not adequately address the needs of the actual project.

At Melkib, we support the selection of adhesives, tapes and dispensing technologies according to specific substrates and manufacturing conditions. Where appropriate, we can help compare solutions and plan application trials. This support does not replace the formal conformity assessment or biological safety evaluation of the finished medical device, which remains the responsibility of its manufacturer.

FAQ – ISO 10993 and adhesive biocompatibility

Does ISO 10993 mean an adhesive is medically certified?

No. ISO 10993 is a series of standards addressing the biological evaluation of medical devices. Testing in accordance with selected parts of the series does not amount to universal certification or approval for every medical application.

Is material testing sufficient to demonstrate the biocompatibility of a finished device?

Not necessarily. The evaluation must consider the finished device, including its design, manufacturing process and conditions of use. Material-level evidence can be important, but it may not be sufficient on its own.

Does every adhesive used in medical device manufacturing need to undergo all ISO 10993 tests?

No. The biological evaluation strategy is determined by the device's characteristics and the biological hazards identified. The need for specific testing should be justified through a documented risk assessment.

Can changing an adhesive curing process affect biological safety?

Yes. Changes to the curing process may affect the properties of the cured material and the levels of residual substances. Their significance must be evaluated in the context of the specific device and manufacturing process.

Does ISO 10993-1:2025 automatically invalidate test reports produced under earlier editions?

No automatic conclusion should be drawn. The scope and relevance of existing data, changes in requirements, device characteristics and the risk evaluation all need to be reviewed. A new edition does not necessarily mean that every previous test result must be discarded.

Can an adhesive used to manufacture syringes also be used for wound closure?

Not on the basis of its assembly application or biocompatibility testing alone. Wound closure must fall within the specified intended purpose and supporting documentation of the individual medical device.

What information should I provide when asking a supplier to recommend an adhesive?

Specify the materials to be bonded, dispensing and curing conditions, mechanical and process requirements, anticipated contact between the finished device and the body, and the documentation required for the project.

Conclusion: ISO 10993 supports biological risk assessment, not automatic adhesive approval

Biocompatibility is not a universal safety label. Biological evaluation must take account of the specific medical device, its materials, manufacturing processes and conditions of contact with the body.

ISO 10993-1:2025 reinforces a structured approach to biological safety evaluation within risk management. For engineers, this means interpreting supplier data carefully and assessing whether the evidence addresses the requirements of the finished device.

Effective adhesive selection starts with understanding the application, not with finding a particular standard number in a catalogue.

Designing or manufacturing medical device components?

If you need an adhesive, technical tape or dispensing system for a specific assembly process, Melkib can help you evaluate suitable solutions in terms of substrate compatibility, processing conditions and available manufacturer documentation.

When submitting an enquiry, describe the intended application, materials to be joined, assembly process and documentation requirements.

Contact Melkib to discuss your application

We do not recommend products for self-treatment or the closure of wounds.

References and technical documentation

This article draws on official standards information, manufacturer documentation and published scientific research. Detailed requirements should always be checked against the complete, current editions of the relevant standards.

• ISO 10993-1:2025 – Biological evaluation of medical devices, Part 1
• Polish Committee for Standardization – PN-EN ISO 10993-1:2026-06
• Commission Implementing Decision (EU) 2026/1231
• Regulation (EU) 2017/745 – Medical Device Regulation
• FDA – Use of International Standard ISO 10993-1
• Henkel – LOCTITE AA 3922
• tesa – 4965 Original Next Gen
• Collins et al. – Cyanoacrylate adhesives as topical haemostatic aids, 1969
• Heisterkamp et al. – Emergency haemostasis using cyanoacrylate adhesive, 1970
• Toriumi et al. – Histotoxicity of cyanoacrylate tissue adhesives, 1990
• Singer et al. – Clinical trial of 2-octylcyanoacrylate, 1998