Cleanroom Classification in Pharmaceutical Manufacturing: ISO 14644 and EU GMP Grades Explained
Cleanroom classification is a critical aspect of pharmaceutical manufacturing, ensuring that sterile products are produced in a controlled environment with minimal contamination risk. Cleanrooms are specially designed and monitored environments where the concentration of airborne particles is controlled to meet specific cleanliness standards. These standards are defined by ISO 14644 and EU GMP (Good Manufacturing Practice) guidelines.
🏭 What Is a Cleanroom?
A cleanroom is a controlled environment designed to minimize contamination from particles, microorganisms, and other impurities. In pharmaceutical aseptic manufacturing, cleanrooms are used to produce sterile drug products such as injectables, eye drops, and infusions. The primary objective is to protect the product, personnel, and environment from cross-contamination.
Cleanrooms maintain control over factors such as:
- Airborne particulate and microbial contamination
- Temperature and humidity
- Air pressure differentials
- Air change rates (ACH – Air Changes per Hour)
- Personnel movement and gowning
- Material flow and equipment layout
📘 Importance of Cleanroom Classification
Cleanroom classification ensures that each area within a pharmaceutical facility meets the required level of cleanliness for its intended operations. It defines the allowable number of airborne particles per cubic meter of air and guides environmental monitoring, cleaning frequency, and HVAC system validation.
Accurate classification is essential for:
- Compliance with regulatory standards (ISO 14644, EU GMP, WHO, US FDA)
- Maintaining product sterility
- Supporting process validation and environmental monitoring
- Reducing the risk of microbial contamination
🧩 ISO 14644 Cleanroom Classification
The ISO 14644-1 standard (International Organization for Standardization) defines cleanroom classification based on the number of airborne particles of different sizes per cubic meter of air. The classes range from ISO Class 1 (cleanest) to ISO Class 9 (least clean).
🧩 ISO 14644-1 Cleanroom Classification (2015)
The ISO 14644-1:2015 standard defines cleanroom classes based on the maximum allowable concentration of airborne particles per cubic meter of air. Classes range from ISO Class 1 (cleanest) to ISO Class 9 (least clean). Compliance with these standards ensures controlled environments for sterile manufacturing, pharmaceuticals, and sensitive electronics.
| ISO Class | ≥ 0.1 µm | ≥ 0.2 µm | ≥ 0.3 µm | ≥ 0.5 µm | ≥ 1 µm | ≥ 5 µm |
|---|---|---|---|---|---|---|
| ISO 1 | 10 | 2 | 0 | 0 | 0 | 0 |
| ISO 2 | 100 | 24 | 10 | 4 | 0 | 0 |
| ISO 3 | 1,000 | 237 | 102 | 35 | 8 | 0 |
| ISO 4 | 10,000 | 2,370 | 1,020 | 352 | 83 | 0 |
| ISO 5 | 100,000 | 23,700 | 10,200 | 3,520 | 832 | — |
| ISO 6 | 1,000,000 | 237,000 | 102,000 | 35,200 | 8,320 | 293 |
| ISO 7 | — | — | — | 352,000 | 83,200 | 2,930 |
| ISO 8 | — | — | — | 3,520,000 | 832,000 | 29,300 |
| ISO 9 | — | — | — | 35,200,000 | 8,320,000 | 293,000 |
Notes:
- “—” indicates that ISO 14644-1 does not define limits for that particle size in the class.
- Lower ISO class number = stricter cleanliness requirement.
- ISO 5–8 are most relevant for pharmaceutical aseptic operations (ISO 5 = Grade A, ISO 6–8 = Grades B–D).
💡 Key Points for Pharmaceutical Cleanrooms
- ISO 5 cleanrooms are required for critical zones like filling and sterile compounding.
- ISO 6–8 are used as background areas for support operations and material preparation.
- Environmental monitoring and validation must be conducted according to ISO 14644-2 for operational performance.
- HEPA filters, airflow rates, and gowning procedures are essential to maintain ISO class compliance.
The higher the ISO class number, the less stringent the cleanliness requirements. ISO 5 and ISO 7 are most relevant for sterile pharmaceutical operations.
💊 EU GMP Cleanroom Classification (Grades A–D)
The European Union Good Manufacturing Practice (EU GMP) Annex 1 divides cleanrooms into four grades (A to D) based on their use and air cleanliness level during both at rest and in operation states.
| Grade | Cleanliness Level | Typical Use | Airborne Particles (≥0.5 µm) per m³ |
|---|---|---|---|
| Grade A | ISO 5 equivalent | Critical aseptic filling, open product handling | 3,520 particles (at rest and in operation) |
| Grade B | ISO 6 equivalent | Background area for Grade A operations | 35,200 (at rest), 352,000 (in operation) |
| Grade C | ISO 7 equivalent | Preparation of sterile components, filtration areas | 352,000 (at rest), 3,520,000 (in operation) |
| Grade D | ISO 8 equivalent | Component washing, support areas | 3,520,000 (at rest), not defined (in operation) |
The combination of air changes per hour (ACH), HEPA filtration efficiency, and pressure differentials maintains these classifications. Grade A typically uses laminar air flow systems providing 0.45 m/s airflow with HEPA filters.
🧠 Relationship Between ISO Classes and EU GMP Grades
The following table shows an approximate correlation between ISO and GMP cleanroom classifications:
| EU GMP Grade | Equivalent ISO Class | Typical Use |
|---|---|---|
| Grade A | ISO 5 | Aseptic core area (filling, open product) |
| Grade B | ISO 6 | Background to Grade A zone |
| Grade C | ISO 7 | Less critical processing stages |
| Grade D | ISO 8 | Support and preparation areas |
💨 HVAC and Airflow Requirements
HVAC systems play a vital role in maintaining cleanroom integrity. The key design principles include:
- Unidirectional airflow in Grade A zones with laminar flow velocity of 0.36–0.54 m/s.
- HEPA filters of ≥99.97% efficiency for ≥0.3 µm particles.
- Pressure differentials of 10–15 Pa between adjacent areas of different grades.
- Temperature: 18–25°C, Humidity: 45–55% RH.
- Air change rate: 240–600 ACH for Grade A, 60–120 ACH for Grade B.
🧫 Environmental Monitoring and Classification Testing
Environmental monitoring verifies the ongoing compliance of cleanrooms. It includes:
- Non-viable particle counting using calibrated particle counters.
- Microbial monitoring with settle plates, contact plates, and active air samplers.
- Monitoring during both at rest and in operation conditions.
- Periodic requalification as per ISO 14644-2 guidelines.
- Trend analysis and CAPA for deviations or excursions.
🔍 Cleanroom Qualification Phases
The cleanroom qualification typically involves the following stages:
- Design Qualification (DQ): Verification that design meets GMP and ISO standards.
- Installation Qualification (IQ): Ensures all components are installed as per specifications.
- Operational Qualification (OQ): Verifies HVAC, HEPA, and pressure differentials function correctly.
- Performance Qualification (PQ): Demonstrates the cleanroom performs consistently under working conditions.
📘 Conclusion
Cleanroom classification forms the foundation of sterile pharmaceutical manufacturing. Understanding ISO and EU GMP standards helps ensure product sterility, regulatory compliance, and patient safety. Maintaining cleanroom conditions through validated HVAC systems, proper gowning, and environmental monitoring ensures continuous control over contamination risks.
With the implementation of ISO 14644-1 and EU GMP Annex 1 guidelines, pharmaceutical manufacturers can achieve consistent cleanroom performance and maintain the highest levels of product quality and sterility assurance.
💬 About the Author
Siva Sankar is a Pharmaceutical Microbiology Consultant and Auditor with extensive experience in sterility testing, validation, and GMP compliance. He provides consultancy, training, and documentation services for pharmaceutical microbiology and cleanroom practices.
📧 Contact: siva17092@gmail.com
📱 Mobile: 09505626106
Comments
Post a Comment
💬 Share your thoughts or questions about this topic below.
I personally reply to every comment — your ideas make this blog better!