What Is ISO 14644-1?

ISO 14644-1:2015 is the international standard that defines cleanroom cleanliness by airborne particle concentration. It classifies cleanrooms into nine ISO classes (ISO 1 through ISO 9) based on the maximum permitted concentration of particles per cubic meter of air, measured at specified particle sizes.

For semiconductor, pharmaceutical, medical device, and precision manufacturing industries, maintaining the correct ISO cleanroom class is not optional — it's a regulatory and customer requirement. A single particle excursion can scrap an entire production batch worth hundreds of thousands of yuan.

ISO Cleanroom Classification Table

The standard defines maximum particle concentrations for each ISO class. Here are the most common classes used in manufacturing:

  • ISO Class 1: The cleanest — maximum 10 particles/m³ at ≥0.1μm. Used in advanced semiconductor lithography.
  • ISO Class 3: Maximum 1,000 particles/m³ at ≥0.1μm. Common in wafer fabrication clean bays.
  • ISO Class 5: Maximum 100,000 particles/m³ at ≥0.1μm (equivalent to old FS209E Class 100). Standard for semiconductor packaging and pharmaceutical aseptic filling.
  • ISO Class 7: Maximum 10,000,000 particles/m³ at ≥0.1μm (equivalent to FS209E Class 10,000). Common in medical device assembly and precision machining.
  • ISO Class 8: Maximum 100,000,000 particles/m³ at ≥0.1μm (equivalent to FS209E Class 100,000). Typical for general clean manufacturing.

Key Monitoring Requirements

ISO 14644-1:2015 specifies how cleanroom classification should be verified:

  • Sampling locations: Determined by the cleanroom area. The standard provides a formula: NL = √A (where NL is the minimum number of sampling locations and A is the cleanroom area in m²).
  • Sample volume: Must be sufficient to detect at least 20 particles at the target particle size for the target ISO class.
  • Sampling time: Minimum 1 minute per location for classification purposes.
  • Particle sizes: For ISO Class 5 and cleaner, at least two particle size thresholds must be measured. For ISO Class 6 and above, one threshold (typically 0.5μm or 5.0μm) may be sufficient.

ISO 14644-2: Monitoring Frequency

ISO 14644-2 defines the ongoing monitoring requirements after initial classification. The monitoring frequency depends on the ISO class and risk assessment:

  • ISO Class 5 and cleaner: Continuous monitoring recommended for critical areas; minimum every 6 months for classification re-verification.
  • ISO Class 6–7: Every 6–12 months for classification re-verification, with continuous or periodic monitoring of key parameters.
  • ISO Class 8: Annual classification re-verification typically sufficient, with periodic particle monitoring at key locations.

The Compliance Challenge — And the Solution

Traditionally, cleanroom compliance has been a manual, labor-intensive process: technicians walking the floor with handheld particle counters, recording numbers on clipboards, compiling reports in spreadsheets. This approach has several critical weaknesses:

  • Point-in-time snapshots: You know the cleanroom was compliant at 10:00 AM on Tuesday. What about 2:00 AM on Sunday?
  • Delayed response: An excursion is discovered days later, after affected product has already shipped.
  • Audit burden: Compiling 6–12 months of compliance data for a customer audit takes days of engineering time.

Automated cleanroom monitoring solves all three problems:

  • Continuous monitoring: Fixed particle counters and environmental sensors provide 24/7 coverage. You have a complete record, not periodic snapshots.
  • Real-time alerts: When particle counts exceed classification limits, the system notifies the responsible personnel within seconds. Investigation begins immediately — not at the next scheduled check.
  • One-click compliance reports: Automated ISO 14644-1 classification calculation, trend analysis, and excursion logs. Generate audit-ready PDF reports in under a minute.

GLORITEC's cleanroom monitoring solution integrates particle counters from leading manufacturers (PMS, Lighthouse, TSI) into a unified IoT platform with SPC control charts and automated ISO 14644-1 compliance reporting. Cleanroom managers can view real-time particle data, temperature, humidity, and pressure differentials on a single dashboard — on desktop, tablet, or phone.