Introduction to ISO Class 5 Cleanrooms
ISO Class 5 cleanrooms represent a critical environment for industries requiring exceptionally high cleanliness and contamination control levels. These specialized facilities maintain strict particle count limitations and environmental parameters to ensure product integrity, research accuracy, and compliance with international standards.
Whether you’re in pharmaceuticals, microelectronics, or biotechnology, understanding ISO Class 5 requirements is essential for successful implementation and operation.
Understanding Cleanroom Classifications
The ISO 14644-1 Standard
The International Organization for Standardization (ISO) established the ISO 14644-1 standard to classify cleanrooms based on airborne particulate cleanliness. This globally recognized framework replaced the Federal Standard 209E (FS209E) system.
Though some industries still reference the older US FED STD 209E Class 100 designation when discussing ISO Class 5 environments.
ISO Classification System Overview
ISO cleanroom classifications range from ISO Class 1 (most stringent) to ISO Class 9 (least stringent). Each class specifies the maximum allowable concentration of particles per cubic meter of air at specified particle sizes. The classification is determined by the number of particles ≥0.5μm per cubic foot of air.
ISO Class 5 Specific Requirements
Particle Concentration Limits
ISO Class 5 cleanrooms must maintain particle counts below the following thresholds:
These strict limitations require continuous monitoring and control systems to maintain compliance.
Air Change Rates
ISO Class 5 cleanrooms typically require 240-480 air changes per hour (ACPH), significantly higher than lower-classified cleanrooms.
This high air turnover rate helps maintain particle concentration within acceptable limits by continuously filtering the room’s air volume.
Air Flow Patterns
Class 5 environments implement unidirectional (laminar) airflow systems that move air in a single direction through HEPA or ULPA filters at a uniform velocity of 0.2-0.5 m/s.
This carefully controlled airflow pattern minimizes turbulence and prevents particle accumulation.
Design and Construction Specifications
Structural Requirements
- Wall and Ceiling Systems: Non-shedding, non-porous materials with minimal seams and ledges.
- Flooring: Seamless, anti-static, and chemical-resistant surfaces.
