EN ISO 28439:2011 PDF

Overview

EN ISO 28439:2011 (ISO 28439:2011) - Workplace atmospheres - Characterization of ultrafine aerosols/nanoaerosols - Determination of the size distribution and number concentration using differential electrical mobility analysing systems (DMAS)

This standard gives guidelines for measuring the number concentration and size distribution of ultrafine aerosols and nanoaerosols in workplace atmospheres using mobility particle sizers (also called differential mobility analysers or DMAS). It focuses on the particle fraction of aerosols and on exposure metrics relevant to nanoscale particles (number and surface area concentrations). The document covers instrument principles, workplace sampling issues, calibration, maintenance, measurement uncertainty and the reporting of results, and describes potential limitations relevant to compliance and limit-setting.

Key topics and technical requirements

• Principle & equipment: operation of differential electrical mobility analysing systems (DMAS), including sampling line, pre-separator, particle charge conditioner, differential electrical mobility classifier (DEMC) and aerosol particle detector.
• Measurement strategy & procedure: recommended preparation, sampling approaches and data evaluation for workplace measurements of ultrafine/nanoaerosols.
• Calibration & performance checks: procedures to verify particle classification and number-counting efficiency of the DMAS; routine checks to ensure reliable operation.
• Uncertainty & errors: identification and treatment of key error sources - CPC/CNC counting efficiency, multiply charged particles, sampling losses, overloading, fibre sampling, humidity effects and maintenance-related issues.
• Reporting: standardized reporting of size-distribution and number-concentration results, and associated uncertainties.
• Limitations: guidance on potential problems that must be considered when defining exposure limits or carrying out compliance measurements.

Practical applications and users

• Primary users: occupational hygienists, industrial hygiene laboratories, exposure scientists and researchers assessing workplace exposure to ultrafine and nanoscale aerosols.
• Typical applications:
  • Characterizing ultrafine particle emissions from processes and equipment.
  • Establishing workplace area-monitoring strategies for nanoparticles.
  • Supporting exposure assessments used in risk evaluation, control selection and regulatory compliance.
• Important note: DMAS systems described in the standard are generally not suitable for personal (wearable) exposure monitoring; they are intended for area and task-based measurements.

Related standards

• ISO/TR 27628 - Ultrafine, nanoparticle and nano-structured aerosols - inhalation exposure characterization and assessment (normative reference cited in ISO 28439).
• ISO 15900 (referenced for terminology related to particle charge equilibrium).

Keywords: EN ISO 28439:2011, ISO 28439:2011, workplace atmospheres, ultrafine aerosols, nanoaerosols, DMAS, differential mobility analyser, size distribution, number concentration, mobility particle sizers, occupational hygiene, measurement uncertainty, calibration.