ISO-certified cleanrooms provide the controlled conditions required to convert and/or assemble medical devices that meet stringent regulatory and safety standards. By maintaining extremely low levels of airborne particles and microbial contaminants, cleanrooms enable manufacturers to safeguard product quality throughout each stage of production.
At BDK, we understand compatibility with ISO cleanroom requirements is essential for ensuring product integrity and regulatory compliance. Here are the key components of certified ISO cleanrooms and how we comply.
ISO Cleanroom Classifications
ISO classification is governed primarily by ISO 14644-1 which specifies airborne particulate concentrations within different cleanroom classes. Ranging from ISO Class 1 to Class 9, each level defines thresholds for particle counts based on size and volume. View the table detailing the number and size of particles permitted per volume of air here.
Medical device manufacturers typically operate in classes between ISO 5 and ISO 8, depending on device complexity and sterility requirements. Maintaining these classifications depends on several variables:
- Particle concentration limits measured in particles per cubic metre
- Airflow design that either directs or dilutes airborne contaminants
- Pressure differentials to ensure controlled directional flow between clean and less-clean zones
These factors together ensure a stable, contamination-controlled environment during device manufacturing, prototyping, assembly, packaging, and testing.
Air Handling & Filtration Systems
Air handling systems are designed to remove particles and maintain air quality at the specified ISO level. Two filtration types are commonly used in cleanroom applications, but applications are dependent on the test method and metric:
HEPA Filters
High Efficiency Particulate Air (HEPA) filters are commonly rated at 99.97% efficiency at the most penetrating particle size/MPPS under standard test methods, making them suitable for ISO 5–8 environments.
ULPA Filters
Ultra-Low Penetration Air (ULPA) filters are specified to higher efficiencies of 99.999% under EN1822 test conditions for smaller particle sizes and are used when more stringent control is required.
Airflow design also plays a critical role:
- Laminar (unidirectional) flow pushes clean air in parallel streams, minimising turbulence and reducing particle resuspension, and is typically used for small, high-risk work zones.
- Turbulent flow uses a dilution model to maintain cleanliness over larger, less sensitive areas where absolute particle control is less critical.
Environmental parameters such as temperature, humidity, and pressure must also be precisely controlled. Even minor fluctuations can affect adhesive curing, material stability, and device performance.
Contamination Control Measures
People, materials, and equipment are the primary sources of contamination in controlled environments. Effective cleanroom design incorporates robust contamination control measures, including personnel protocols, surface and structural materials, tools and equipment maintenance.
Personnel Protocols
Trained personnel are essential within medical manufacturing, however human activity can release thousands of particles per minute, even in full gowning. This is why there is usually controlled entry procedures, specialised gowning sequences, restricted movement and behaviour and strict hygiene requirements.
Design & Operational Best Practices
Optimising cleanroom performance demands careful planning and ongoing operational discipline. The design of the cleanroom is crucial in maintaining a stable, contamination-controlled environment. Best practices include:
- Layout optimisation to streamline workflow and minimise contamination risks
- Use surface and structural materials designed for low particle generation and easy sanitisation such as seamless flooring, non-shedding wall panels, stainless steel or coated furniture and smooth surfaces
- Scheduled maintenance for filtration equipment, HVAC systems, and environmental monitoring devices
- Regular cleaning protocols aligned with ISO and GMP standards
- Comprehensive training programmes to maintain personnel competency and ensure procedural consistency
Ensuring these practices are consistently applied helps maintain cleanroom stability and quality throughout the device lifecycle.
Tools & Equipment Maintenance
All equipment must be meticulously sterilised and maintained to reduce particulate or microbial emission. Even routine operations, such as adhesive dispensing or substrate handling, must be controlled to prevent contamination.
Materials & Adhesive Considerations in Cleanrooms
Adhesives used in medical device assembly must be formulated for compatibility with controlled environments. Key considerations include:
Low Outgassing (VOC Control)
Outgassing can compromise cleanroom air quality and risk device contamination. Low-VOC, low-particulate adhesives are preferred to maintain compliance and protect sensitive components.
Biocompatibility
Adhesives used in medical devices must meet biocompatibility standards to ensure they do not introduce harmful substances or degrade device performance.
Pre-Approved Cleanroom-Compatible Materials
Using materials that meet ISO and GMP standards streamlines validation processes and reduces the risk of contamination incidents.
Companies like BDK develop adhesive solutions engineered specifically for the controlled conditions found in ISO-certified cleanrooms. Our products are designed to support reliable bonding performance without compromising environmental compliance or introducing unwanted particulates.
Environmental Monitoring Systems
Continuous environmental monitoring is also essential to ensure a cleanroom consistently performs at its designated ISO class. Monitoring typically includes:
Particle Counting: Automated systems detect and record airborne particulate concentrations at regular intervals.
Airborne Microbial Testing: Active and passive sampling devices set microbial limits and monitor expectations based on standards such as ISO 14698 for biocontamination and regulatory guidance e.g., GMP Annex 1 for sterile products
*Particulate and microbial monitoring are complementary but different.
Environmental Parameter Monitoring: Systems measure temperature, humidity and pressure differentials. All monitoring results must be documented for regulatory review, quality audits, and traceability.
In many facilities, system upgrades or procedural changes are made to meet stricter monitoring standards. Moving from Level 4 to Level 3 monitoring, for example, requires more frequent checks and tighter control limits demonstrating a higher commitment to environmental assurance which BDK have recently implemented.
Regulatory & Compliance Considerations
Cleanrooms supporting medical device production must align with both ISO 14644 and Good Manufacturing Practice (GMP) requirements.
Key compliance elements include integration with a facility’s Quality Management System (QMS). This means documented validation of cleanroom processes and performance, as well as supplier qualification for materials used within the controlled environment.
Strong alignment between cleanroom operations, material selection, and QMS processes is essential for meeting regulatory expectations too. Routine audits and recertification cycles ensure consistent product quality and compliance.
ISO-certified cleanrooms are fundamental to the safe and compliant manufacture of medical devices. Achieving and maintaining these controlled environments relies on careful integration of air handling systems, contamination control, material selection, and environmental monitoring.
By working with adhesive specialists such as BDK, manufacturers can ensure their adhesives and bonding processes support both device integrity and cleanroom compliance strengthening performance, reliability, and regulatory compliance across the development cycle. Contact us today to get your project started.