ISO 14644-12:2018

Overview

ISO 14644-12:2018 specifies methods and requirements for monitoring air cleanliness in cleanrooms and associated controlled environments by nanoscale particle concentration. The standard covers airborne particles with a lower size limit of 0.1 µm (100 nm) or less - defined as “nanoscale” - and is intended primarily for use in the operational state of a cleanroom, when process equipment and personnel are active. Health and safety considerations are explicitly excluded.

Key topics and technical requirements

• Scope of measurement: Focus on particle number concentration of nanoscale particles (≈1–100 nm), using an equivalent diameter metric.
• Reference detection method: Condensation Particle Counter (CPC) is the preferred detector; Annex A provides the CPC reference method.
• Counting performance: Counting efficiency and particle size cutoff (D50 - the particle size at 50% counting efficiency) are addressed (see Annex B).
• Monitoring plan elements: Establishes that monitoring should be based on a risk assessment and include:
  • nanoscale particle size range to measure
  • sampling time-dependence and sample volume
  • sampling locations and number of samples
  • criticality of process/product and clean zone layout
• Calibration and traceability: Tests must be performed with calibrated instruments and documented calibration status.
• Test reporting: Required report content includes test location coordinates, occupancy state, instrumentation and calibration details, lower particle size limit reported, CPC zero count rate, and a summary assessing trends and alert/action limits.

Applications and who uses this standard

ISO 14644-12 is applicable where nanoscale contamination monitoring supports process control and product quality. Typical users include:

• Cleanroom operators and facility managers in microelectronics, nanotechnology, aerospace, pharmaceuticals, medical device and healthcare manufacturing
• Process engineers designing contamination control and monitoring programs
• Third‑party testing organizations reporting cleanroom performance in operational states
• Quality and compliance teams creating risk-based monitoring plans for products sensitive to nanoscale particles

This standard is especially relevant when process-related nanoscale particles are expected (e.g., from equipment, chemical reactions or manufacturing processes), since measurements are intended to reflect operational conditions.

Related standards

• ISO 14644 series (classification, test methods, monitoring plans) - notably ISO 14644-1 and ISO 14644-2 referenced for classification and monitoring plan requirements
• ISO 14644-3 (historical related material on ultrafine particles)
• ISO/TS 80004-2 (nanotechnologies terminology)
• ISO 15900 (aerosol terminology)

Keywords: ISO 14644-12, nanoscale particle concentration, cleanrooms, monitoring air cleanliness, CPC, condensation particle counter, nanoparticle monitoring, clean zone.