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What is an ISO 7 Cleanroom?
An ISO 7 cleanroom (Class 10,000) is a controlled environment defined by the ISO 14644-1 standard where the concentration of airborne particles ≥0.5 µm is maintained at or below 352,000 particles per cubic meter (10,000 per cubic foot). It serves as a critical intermediate-level clean zone for manufacturing and scientific processes that require stringent contamination control but not the extreme purity of higher-grade cleanrooms.
Airborne Particle Limits
The iso 14644-1 standard sets strict particle count limits to define an ISO 7 cleanroom's classification. These limits are verified through certified particle counters at specified intervals, ensuring the environment consistently meets its required cleanliness level during operational states.
- ≥0.5 µm: 352,000 particles/m³ | 10,000 particles/ft³
- ≥1.0 µm: 83,200 particles/m³
- ≥5.0 µm: 2,930 particles/m³
Air Changes Per Hour (ACH)
Air Changes Per Hour (ACH) is a fundamental engineering parameter that dictates how effectively a cleanroom can dilute and remove airborne contaminants. For an ISO 7 cleanroom, a high ACH rate is necessary to overwhelm the particle generation from equipment, processes, and personnel.
While the ISO standard is performance-based (it specifies the particle count outcome, not the method), industry best practices from organizations like the IEST recommend a typical range of 30 to 40 ACH for an ISO 7 environment. Specialists at Deiiang™ perform precise calculations based on room size, process load, and personnel count to determine the exact ACH needed for stable, compliant performance.
Airflow
Effective contamination control is impossible without proper airflow design. The goal is to sweep particles away from critical zones and toward returns.
1. Unidirectional Flow
Often used over key production lines, this airflow moves in a single, uniform direction (e.g., ceiling to floor) with minimal turbulence. It creates a "sweeping" effect that protects products from particulate contamination.
2. FFU (Fan Filter Unit)
These are self-contained modules, each with a fan and a HEPA filter, mounted in the ceiling grid. They are a flexible and efficient solution for creating the necessary unidirectional or mixed airflow patterns in an ISO 7 cleanroom.
3. HVAC & AHU
The central Air Handling Unit (AHU) is the heart of the cleanroom's HVAC system. It conditions the air (temperature and humidity control) and provides sufficient pressure to push it through a final HEPA filtration stage, which is mandatory for achieving ISO 7 classification.
Gowning
Personnel are the largest source of contamination in any cleanroom. Therefore, a strict gowning procedure is a non-negotiable requirement for entering an ISO 7 environment. The protocol is designed to contain particles and microcontaminants shed from skin, hair, and street clothing.
Typical attire for an ISO 7 cleanroom includes a hood, coverall, boot covers, gloves, and a face mask. This process always occurs in a series of airlocks or gowning rooms, which are maintained at a higher pressure than the adjacent corridor but a lower pressure than the main cleanroom to prevent ingress of unclean air. Deiiang Jason.peng emphasizes that proper gowning is the most cost-effective contamination control measure.
Applications
ISO 7 Cleanrooms are versatile workhorses, providing the essential clean environment for a wide array of advanced industries where product quality is paramount.
Medical Device Assembly
(e.g., implants, surgical tools)
Pharmaceutical Manufacturing
(non-sterile dosage forms)
Biotechnology and Vaccine Production
Aerospace
(component manufacturing)
Advanced Electronics and Optics
Plastics Manufacturing
Which is better, ISO 7 or ISO 8?
"Better" is entirely dependent on the specific application and its contamination control requirements. An ISO 7 cleanroom is classified to allow ten times fewer particles ≥0.5 µm than an ISO 8 (Class 100,000) cleanroom. Therefore, for processes that are more sensitive to particulate contamination or are a precursor to sterile operations, an ISO 7 is objectively better and necessary.
Conversely, if a process only requires a moderately clean environment for basic protection, an ISO 8 Cleanroom may be perfectly sufficient and more cost-effective to build and operate. The choice is a calculated decision based on risk assessment, regulatory guidelines, and process needs.
| Feature | ISO 7 Cleanroom (Class 10,000) | ISO 8 Cleanroom (Class 100,000) |
|---|---|---|
| Max Particles (≥0.5µm / ft³) | 10,000 | 100,000 |
| Air Changes Per Hour (ACH) | 60-90 | 20-40 |
| Typical Airflow | Unidirectional over critical zones | Mixed, non-unidirectional |
| Filtration | HEPA filters mandatory | HEPA filters typically used |
| Application Sensitivity | Medium-High | Low-Medium |
| Operational Cost | Higher | Lower |
ISO 7 Cleanroom Standards and Requirements
Adherence to recognized standards is what separates a compliant cleanroom from a mere clean space. These standards provide the framework for every aspect of design, construction, and operation.
Standards:
- ISO 14644-1: Classification of Air Cleanliness (defines particle counts).
- iso 14644-2: Monitoring to prove continued compliance.
- ISO 14644-4: Design, construction, and start-up.
- iso 14644-5: Operations (procedures for cleaning, gowning, etc.).
Requirements:
A comprehensive ISO 7 cleanroom solution from a provider like Deiiang™ integrates all these elements.
| Category | Key Requirements |
|---|---|
| Architectural | Smooth, non-shedding, cleanable surfaces (e.g., vinyl walls, epoxy floors). Airlocks and pressure cascades. |
| HVAC & Filtration | HEPA filtration coverage (ceiling). Capable of maintaining 60-90 ACH. Positive pressure relative to less clean areas. |
| Monitoring & Control | Continuous particle counting. Pressure differential monitoring. Temperature and humidity control (±2°F, ±5% RH typical). |
| Operational Procedures | Strict gowning protocols. Validated cleaning regimens. Material transfer procedures. Personnel training. |
Conclusion
An ISO 7 cleanroom is a precisely engineered and meticulously maintained environment that is fundamental to modern high-tech manufacturing and research. Its value lies in its ability to reliably control particulate contamination to a defined, intermediate level, balancing operational requirements with cost-effectiveness. Success hinges on a holistic approach that integrates rigorous international standards, robust architectural and mechanical design from experts like Deiiang™, and unwavering adherence to disciplined operational procedures. Ultimately, implementing an ISO 7 cleanroom is an investment in product quality, consumer safety, and manufacturing excellence.
© 2023 Cleanroom Standards Guide. All rights reserved.
Designed with expertise from Deiiang™ cleanroom specialists
