What Is an ISO Class 7 Cleanroom?
An ISO Class 7 cleanroom is a cleanroom or clean zone classified according to ISO 14644-1 based on airborne particle concentration. Maintaining that classification typically requires a broader system of filtration, airflow, pressure control, cleaning, gowning, monitoring, and periodic testing. The specific controls depend on the process, occupancy, contamination risks, and applicable industry requirements. For a detailed comparison of ISO Classes 1 through 9, see the ISO Cleanroom Classifications Chart & Guide.
For ISO Class 7 classification and ongoing control, key considerations include:
- Particle Concentration: ISO Class 7 permits no more than 352,000 particles ≥0.5 µm and 2,930 particles ≥5 µm per cubic meter of air. Classification testing is performed at the agreed occupancy state, for example, as-built, at-rest, or operational, using the sampling locations and procedures established by ISO 14644-1.
- Filtration and Airflow: Cleanrooms commonly use HEPA-filtered supply air and sufficient airflow to dilute and remove particles generated by personnel, equipment, and processes. The appropriate airflow pattern and air change rate are established through design and performance qualification; ISO 14644-1 does not assign one universal air change rate to ISO Class 7.
- Temperature and Humidity: Facilities establish temperature and relative-humidity ranges based on process needs, personnel comfort, material stability, and applicable requirements. Stable conditions can also support consistent room and equipment performance.
- Personnel Practices: Because personnel are a major contamination source, facilities establish gowning, entry, material-transfer, and behavior procedures appropriate to the process risk. Garments may include hair and beard covers, low-shedding apparel, gloves, masks, and shoe covers, but the required garbing is not determined by ISO Class 7 alone.
- Cleanroom Design: Cleanroom finishes and components are generally selected to minimize particle generation, resist deterioration, and support effective cleaning. Layout, return/exhaust-air placement, equipment, personnel flow, and material flow should align with the facility's contamination-control strategy.
- Pressure Control: Positive pressure is commonly used to protect cleaner spaces from adjacent areas. Negative pressure may instead be appropriate when hazardous materials or processes must be contained. The pressure relationship should support the intended contamination-control objective and applicable requirements.
ISO Class 7 environments are used in pharmaceutical, biotechnology, medical-device, electronics, aerospace, healthcare, and research applications. The appropriate classification and supporting controls should be selected from the actual sensitivity and contamination risk of the product or process.
How TSS Supports ISO Class 7 Classification and Performance Testing
Technical Safety Services provides cleanroom testing and certification services for controlled environments across a range of industries.
Depending on the facility's requirements and testing scope, TSS testing may include:
- Accurately assessing your facility’s airflow volume
- Testing the integrity of your HEPA filter system
- Measuring non-viable airborne particulate levels
- Calculating room air exchange rate
- Measuring room differential pressure
- Measuring temperature and relative humidity
- Conducting viable environmental monitoring
To learn more about Technical Safety Services’ approach to cleanroom air monitoring services, or to get started on a new project, please contact us today to schedule a consultation or receive a quote.
