Engineers designing devices with internal fluid pathways — blood analyzers, infusion pumps, dialysis machines, ventilator flow manifolds, and point-of-care diagnostic cartridges — frequently encounter the question of whether their adhesive bonding material requires special regulatory approval before use in a fluid-contact component. The answer is nuanced: no regulatory authority specifically approves adhesives for medical device use, but the regulations governing medical device safety create requirements for the device manufacturer to demonstrate that the materials in fluid-contact components do not cause patient harm. Understanding what that demonstration actually requires — and what it does not require — prevents both the misconception that any listed or tested adhesive is automatically approved, and the opposite misconception that fluid-contact adhesive use requires separate regulatory authorization.
No Adhesive Is “Approved” for Medical Use
The U.S. FDA, European MDR, and equivalent regulatory frameworks do not maintain a list of approved medical-grade adhesives that device manufacturers can use freely. What exists instead is a framework of standards and guidance documents that describes how device manufacturers must evaluate materials for patient safety, and what evidence they must generate and maintain to demonstrate that their specific device is safe for patient use.
This means that the phrase “FDA-approved adhesive” or “FDA-cleared adhesive” — sometimes used loosely in the industry — has no regulatory meaning. FDA clears or approves devices, not materials. A material that has been used in a cleared or approved device is part of that specific device’s data package; it does not carry approval that can be generically applied to any other device.
What a device manufacturer can do is use an adhesive that has been characterized for biocompatibility through ISO 10993 testing, reference that data in the device biological evaluation report, and demonstrate that the material use in the specific device is within the bounds of the tested conditions. If the adhesive supplier has conducted this testing, the manufacturer leverages existing data. If not, the manufacturer must generate it.
The Extractables and Leachables Framework
For fluid-contact applications, the relevant regulatory pathway runs through extractables and leachables (E&L) assessment — a process defined primarily in ISO 10993-17 (toxicological risk assessment) and ISO 10993-12 (sample preparation and reference materials).
Extractables are chemical entities that can be removed from a material under aggressive laboratory conditions — typically solvent extraction at elevated temperature using both polar and nonpolar solvents. They represent the universe of chemical compounds present in the material that could potentially reach the patient.
Leachables are the subset of extractables that actually migrate from the material into the clinical fluid under normal use conditions. The patient is exposed to leachables, not to extractables in general — but extractables testing is performed first as a conservative screening step.
The toxicological risk assessment applies compound-specific permitted daily exposure (PDE) values — derived from available toxicology data — to the identified leachable quantities to determine whether the patient’s daily exposure is below thresholds for harm. For leachables with established PDEs well above the measured exposure, the risk assessment is straightforward. For leachables without established PDEs, a compound-specific assessment using risk-based approaches must be developed.
For extractables characterization and toxicological risk assessment support for fluid-contact epoxy applications, Email Us — Incure can provide extraction data for specific formulations to support the E&L assessment.
What Must Be Evaluated vs What Is Determined by Testing
The regulatory requirement for fluid-contact adhesive materials is not that specific tests must be run in all cases — it is that the device manufacturer must have evidence supporting a conclusion of safety for the specific use. This evidence can come from:
Existing supplier-conducted testing: If the adhesive supplier has conducted ISO 10993-5, -10, and extractables testing on the specific formulation, the device manufacturer can reference this data in the biological evaluation report, document how the device’s use conditions compare to the test conditions, and conclude that the existing data supports safety for the specific application. This is the preferred path because it avoids redundant testing.
Existing published literature or industry data: If the adhesive chemistry is identical to that of materials previously characterized in peer-reviewed literature or standardized reference material databases, this information can be used to support the risk assessment.
New testing: If no adequate existing data exists, the device manufacturer must commission testing on the adhesive at the device-relevant cure conditions and use environment. This is the most resource-intensive path but is required when neither of the above is available.
The choice between these paths is a risk-based judgment, not a fixed rule. The FDA guidance on use of international standards (2007) and the MDR’s reference to ISO 10993 establish the framework but do not mandate a specific testing path for every material in every device.
Practical Compliance for Fluid-Contact Bonding
For a device manufacturer developing a diagnostic cartridge with epoxy-bonded flow cell components, the practical compliance path is:
Select a medical-grade epoxy formulated for low extractables in aqueous conditions. Obtain from the supplier the existing ISO 10993 test data and any extractables data available for the product at the production cure schedule. Document in the device biological evaluation plan how the existing data addresses the device’s use conditions. If gaps exist — if the fluid contact conditions in the device are more aggressive than the test conditions, or if extractables above the analytical evaluation threshold are present — conduct targeted additional testing to address those gaps. Summarize in the biological evaluation report.
This process — drawing on supplier data, identifying gaps, addressing gaps with additional data where needed — is more efficient than commissioning a full new battery of biocompatibility tests for an adhesive that already has a substantial data package from the supplier.
Regulatory submissions should include the biological evaluation report with the underlying test reports cited. Reviewers will examine whether the test conditions match the device use conditions; discrepancies between how the adhesive was tested and how it is used in the device are the most common deficiency in material evaluation submissions.
Contact Our Team to discuss fluid-contact epoxy selection, extractables data packages, and biological evaluation documentation support for diagnostic and fluid-handling medical device applications.
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