ISO 13138:2012 PDF

Overview - ISO 13138:2012 (Air quality, airborne particle deposition)

ISO 13138:2012 specifies sampling conventions to define idealized samplers for estimating where inhaled airborne particles deposit in the human respiratory system. It applies to non-volatile, non-hygroscopic, non-fibrous aerosols and defines deposition fractions for five loci of the respiratory tract:

• anterior nasal passages,
• posterior nasal passages (larynx and pharynx),
• ciliated tracheobronchial region,
• non‑ciliated tracheobronchial (bronchioles/terminal bronchioles), and
• alveolar (gas-exchange) region.

The standard separates deposition behavior into diffusion-dominated (thermodynamic diameter for sub‑micrometre particles) and inertia/gravity/interception‑dominated processes (aerodynamic diameter for particles > 0.1 μm). Each conventional deposition curve is averaged over 12 breathing conditions (sitting → heavy exercise, male/female, mouth vs nasal breathing).

Key topics and technical requirements

• Particle property scope: Non-volatile, non-hygroscopic, non-fibrous aerosols only.
• Size metrics:
  • Thermodynamic diameter for Brownian (diffusive) motion of sub‑micrometre particles.
  • Aerodynamic diameter for impaction, interception and settling processes (>0.1 μm).
• Deposition efficiencies: Three efficiencies expressed in thermodynamic diameter and four in aerodynamic diameter to represent deposition in the five loci.
• Breathing-condition averaging: Curves derived as averages of 12 breathing scenarios (tidal volume, breathing rate, inspiratory flow variations).
• Assumptions and modelling: Deposition computed using models (ICRP referenced); the standard documents assumptions, approximations, and uncertainty considerations.
• Intended outputs: Idealized sampler definitions and conventional curves to estimate deposited fractions and to support dose estimation in specific lung regions.

Applications and practical value

• Health-effects research: Improves estimation of deposited dose (mass or number) in target lung regions to study exposure–response relationships.
• Occupational and environmental hygiene: Guides development and evaluation of samplers and monitoring strategies that better represent deposited dose rather than mere inhaled fractions.
• Instrument design and performance testing: Manufacturer and testing labs can use the conventions to design samplers and verify performance against target deposition curves.
• Regulatory and standards evolution: Supports potential revision of exposure limits and compliance criteria if deposited‑dose metrics prove more predictive of health outcomes.

Who should use ISO 13138:2012

• Occupational hygienists and environmental health professionals
• Aerosol scientists and exposure modelers
• Air sampling instrument designers and test laboratories
• Regulators and researchers conducting inhalation toxicology or epidemiology studies

Related standards

• ISO 7708 - Particle size fraction definitions for health-related sampling
• EN 481 - Size fraction definitions for airborne particle measurement
• EN 13205 - Performance assessment of instruments for airborne particle measurement
• ISO/IEC Guide 98-3 (GUM) - Uncertainty of measurement
• ICRP deposition models (referenced for computational basis)

Keywords: ISO 13138:2012, air quality, airborne particle deposition, respiratory system, sampling conventions, aerosols, aerodynamic diameter, thermodynamic diameter, occupational hygiene, health-effects research.