ISO 29463-2:2011

Overview - ISO 29463-2:2011 (Aerosol production & particle-counting)

ISO 29463-2:2011 is the Part 2 document of the ISO 29463 series for high-efficiency filters and filter media. It specifies requirements for aerosol production, the measuring equipment used to test HEPA/ULPA filters and filter media, and the statistical basis for particle counting when only a small number of events are counted. This part is intended for use with ISO 29463‑1, ‑3, ‑4 and ‑5 and is derived from EN 1822 approaches.

Key topics and technical requirements

• Aerosol generation methods
  • Preferred liquid test aerosols and suitable substances (examples: DEHS, PAO, low‑viscosity paraffin oil).
  • Mono‑disperse production by condensation (heterogeneous and homogeneous condensation).
  • Example generators described: Rapaport–Weinstock (heterogeneous) and free‑jet condensation (homogeneous).
  • Requirements to control mean particle diameter (adjust to MPPS) and maintain stable concentration/size distribution during tests.
• Measuring equipment
  • Guidance on instruments commonly used in filter testing: optical particle counters (OPCs), condensation particle counters (CPCs), differential mobility analyzers (DMAs), aerosol photometers, dilution systems, and environmental sensors (pressure, temperature, humidity).
  • Recommendations for instrument performance, calibration, maintenance and sources of measurement error.
• Particle‑counting statistics
  • Statistical methods for counting when downstream event counts are low-critical for high‑efficiency and ultra‑low penetration air filters.
  • Concepts such as counting efficiency and handling of low-count uncertainties.
• Operational and safety guidance
  • Handling and exhaust requirements for test aerosols; maintenance and inspection intervals for equipment.

Practical applications and users

• Used to design, validate and execute standardized filter efficiency tests for HEPA/ULPA media and elements.
• Typical users:
  • Filter and media manufacturers (quality control and R&D)
  • Independent test and certification laboratories
  • Cleanroom and HVAC engineers (acceptance testing)
  • Pharmaceutical, semiconductor, healthcare, nuclear air‑cleaning and other regulated industries needing validated filter performance data
• Enables reproducible testing at the most penetrating particle size (MPPS) (for micro‑glass media typically ~0.12–0.25 µm), assuring reliable classification and certification.

Related standards

• ISO 29463 series: Part 1 (classification), Part 3 (flat sheet media testing), Part 4 (element leakage - scan method), Part 5 (filter elements)
• ISO 29464 (terminology)
• Note: ISO 29463 is derived from EN 1822; consult both where applicable.

Keywords: ISO 29463-2, aerosol production, particle-counting statistics, HEPA testing, ULPA, aerosol generators, optical particle counter, differential mobility analyzer, filter testing.