ISO 14644-1:2015

Overview

ISO 14644-1:2015 - "Cleanrooms and associated controlled environments - Part 1: Classification of air cleanliness by particle concentration" defines how to classify cleanrooms, clean zones and separative devices according to the concentration of airborne particles. The standard covers particle-size thresholds from 0.1 µm to 5 µm, uses light scattering (discrete) airborne particle counters (LSAPC) as the basis for measurement, and retains an M descriptor (Annex C) to quantify macroparticles (>5 µm). ISO 14644-1:2015 specifies the classification method, the reference testing approach (Annex A) and requirements for sampling locations and reporting - but it does not characterize particle chemistry, viability or ultrafine (nano-scale) particles (<0.1 µm).

Key technical topics and requirements

• Particle size range: Classification applies to cumulative particle thresholds between 0.1 µm and 5 µm. Nano-scale particles are outside this part and handled separately.
• Measurement method: Use of LSAPC instruments for counting particles ≥ specified sizes (see Annex F for instrument guidance).
• ISO Classes: Defines integer and intermediate decimal cleanliness classes (tables provide maximum particle concentrations for each class and size).
• Sampling strategy: Statistical approach based on an adapted hypergeometric sampling model; minimum sampling locations referenced in Table A.1. The model provides at least 95% confidence that 90% of the area will meet class limits.
• Designation and reporting: Rules for class number, particle sizes, occupancy states and required test reporting (see Clause 5 and Annex A).
• Macroparticles: Annex C describes counting/sizing of particles >5 µm and use of an M descriptor for regulatory adaptation (e.g., sterile product guidance).

Practical applications

ISO 14644-1:2015 is essential for organizations that design, validate, operate or regulate contamination-controlled environments, including:

• Pharmaceuticals and sterile manufacturing (cleanroom classification and sterile product annex adaptations)
• Medical devices and healthcare facilities
• Microelectronics and semiconductor fabrication
• Aerospace and precision engineering
• Food processing where particulate control is required It is used to establish an ISO Class target, select monitoring and test protocols, validate HVAC and filtration performance, and produce compliance test reports for audits and regulatory inspections.

Who should use this standard

• Cleanroom designers and engineers
• Validation and quality assurance specialists
• Facilities and operations managers
• Test laboratories and auditors
• Regulatory and compliance personnel

Related standards

• ISO 14644‑2 (monitoring to provide evidence of performance)
• ISO 14644‑3 (test methods)
• ISO 14644‑7 (separative devices: hoods, gloveboxes, isolators)
• Other parts of ISO 14644 (Parts 4, 5, 8–10) and ISO 14698 (biocontamination control)

Keywords: ISO 14644-1:2015, cleanrooms, air cleanliness, particle concentration, LSAPC, ISO class, sampling locations, macroparticles, clean zones.