Overview
EN ISO 13138:2012 (ISO 13138:2012) - "Air quality - Sampling conventions for airborne particle deposition in the human respiratory system" defines idealized sampling conventions to estimate where inhaled aerosol particles deposit in the human respiratory tract. The standard applies to non-volatile, non-hygroscopic, non-fibrous aerosols and provides size-selective deposition curves for five specific loci: the anterior and posterior nasal passages, ciliated and non-ciliated tracheobronchial regions, and the alveolar (gas exchange) region.
Key topics
- Sampling conventions: Defines idealized samplers (conventional curves) that represent deposition fractions rather than merely penetration or inhalability.
- Five anatomical loci: Separate conventions for anterior/posterior extrathoracic regions, two tracheobronchial parts, and alveolar region.
- Size metrics:
- Thermodynamic diameter for sub-micrometre, diffusion-dominated deposition (Brownian motion).
- Aerodynamic diameter (>0.1 µm) for impaction, interception and settling processes.
- Efficiency curves: Three efficiencies in terms of thermodynamic diameter and four efficiencies in terms of aerodynamic diameter. Curves are averaged from 12 deposition scenarios (varying breathing modes, activity from sitting to heavy exercise, and male/female differences).
- Model basis: Deposition calculations use the ICRP (International Commission on Radiological Protection) deposition model cited in the standard.
- Scope limits: Intended for non-volatile/non-hygroscopic/non-fibrous particles; applicability to other particle types may be limited.
Applications
EN ISO 13138 is practical for:
- Occupational hygienists and environmental monitoring teams assessing dose-relevant exposure to airborne particles.
- Sampler and instrument designers developing size-selective samplers and monitors that emulate deposition behavior.
- Researchers in inhalation toxicology and epidemiology seeking exposure metrics tied to actual deposition (e.g., alveolar vs tracheobronchial).
- Regulators and standards bodies evaluating or updating exposure assessment methods and compliance testing (research-first adoption is expected before regulatory use).
Practical uses include sampler performance specification, exposure assessment modeling, health-effect research, and instrument calibration against deposition-oriented criteria.
Related standards
- ISO 7708 - Particle size fraction definitions for health-related sampling
- EN 481 - Workplace atmospheres - Size fraction definitions
- EN 13205 - Performance assessment of instruments for airborne particle measurement
- ISO/IEC Guide 98-3 (GUM) - Uncertainty of measurement
Keywords: EN ISO 13138:2012, ISO 13138, air quality, sampling conventions, airborne particle deposition, respiratory tract, aerodynamic diameter, thermodynamic diameter, particle deposition sampling, occupational exposure, environmental monitoring.