In a modern hospital in Munich, clean air is as crucial as precise surgical procedures and effective medications. The high-efficiency particulate air (HEPA /ULPA ) filters that safeguard this cleanliness are far more than ordinary industrial consumables. When defined as “medical” or part of a medical device, they must undergo a stringent approval process forged by regulations, standards, and bioethics to obtain a “legal identity” for clinical use.
Challenges Facing Medical Filters:
- Direct and Indirect Risks: They may function as filters in anesthesia breathing circuits, directly intervening in patient gas exchange and intercepting pathogens; they may also be used in operating room laminar flow ceilings, biosafety cabinets, or medical vacuum systems. Their failure could indirectly lead to large-scale infections or cross-contamination.
- Regulatory Logic:Therefore, global regulatory agencies (such as the US FDA and EU notified bodies) manage them under the categories of “medical devices” or “in vitro diagnostic medical devices.” This means that manufacturers must demonstrate not only filtration efficiency, but also its safety, effectiveness, and consistent performance throughout its intended lifespan.
Medical Filter Performance and Standards
Any medical product must be built upon recognized technical standards. For HEPA filters, the core performance benchmarks are:
- EN 1822 and ISO 29463 : These two standards (currently being merged) are the globally accepted language for filter classification and performance testing. They not only specify filtration efficiency for the most penetrating particle size (MPPS ) (e.g., H13 grade ≥99.95% efficiency for 0.3μm particles, H14 grade ≥99.995%), but more importantly, require that no localized leaks be detected at the filter media and seals using a scanning leak test. A test report conforming to EN 1822-1:2019 is the starting point for technical feasibility.
- Product-Specific Standards: More detailed standards exist for specific medical applications. For example, the ISO 23328 series specifically specifies the filtration performance (salt test method) and non-filtration aspects (such as resistance and dead space) requirements for filters used in anesthesia and respiratory systems.
Market Access Standards for Medical Filters
Passing performance tests is merely obtaining the “entrance ticket.” To gain market access, the core philosophy of “risk management” must be implemented, with its systematic practice aligning with the ISO 14971 standard.
- 1. Risk Analysis and Assessment: Manufacturers must systematically identify the risks of filters under all reasonably foreseeable scenarios, such as: infection due to filter failure, toxicity due to material shedding, leakage due to aging seals, and misuse due to labeling errors.
- 2. Risk Control and Validation: For each risk, control measures must be implemented (such as using higher-efficiency filter media, conducting rigorous sealing process validation, selecting biocompatible materials, and performing aging tests), and the effectiveness of these measures must be proven through validation testing.
- 3. Production and Post-Market Surveillance: Ensure that every product leaving the factory is consistent with the submitted sample, establishing a traceability system. After market launch, feedback must be collected, adverse events monitored, and a closed-loop management system established.
Mainstream Regulatory Standards for Medical Filters
- US FDA: 510(k) or PMA
The US FDA classifies medical devices into Class I, II, and III based on risk. Most medical filters, classified as medium-risk (Class II) devices, are typically approved through the “510(k)” route.
Evidence Submission: The submitted materials are extensive and must include performance test data (often referencing standards such as IEST-RP-CC034), biocompatibility reports (e.g., ISO 10993), sterilization validation, software validation (if applicable), labeling, and a complete risk analysis report.
Unique Device Identifier (UDI): After market approval, the product must have a UDI, whose information will be entered into the publicly available GUDID database for hospitals and regulatory agencies to trace.
- EU CE Certification Pathway: MDR/IVDR
In the EU, filters, as medical devices, must comply with the Medical Devices Regulation (MDR).
Notified Body Review: Companies must choose an EU-designated notified body and submit comprehensive technical documentation.
Conformity Assessment: The notified body reviews the technical documentation (including all design validation, risk management, and clinical evaluation evidence) and audits the production quality system.
Signing of Declaration of Conformity: After passing the audit, the company signs a Declaration of Conformity and affixes the CE marking to the product before it can enter the EU market.
The approval process for medical-grade HEPA/ULPA filters is a rigorous process that integrates physical efficiency, materials safety, engineering reliability, and regulatory rigor. Trenntech believes that it tests not only the performance of the filter but also the manufacturer’s respect for life safety and its ability to implement systematic quality management. Trenntech will continue its relentless pursuit of the ultimate ideal of “zero infection risk.”