Overview
ISO 23861:2022 - Workplace air - Chemical agent present as a mixture of airborne particles and vapour - Requirements for evaluation of measuring procedures using samplers - defines a consistent framework for evaluating measuring procedures that determine a chemical agent present in the workplace atmosphere as a mixture of airborne particles and vapour. The standard applies to sampling trains and laboratory analysis carried out in separate stages and provides requirements for reporting the combined concentration (mass per unit volume) of particle‑ and vapour‑phase fractions.
Key technical topics and requirements
- Scope and purpose: Validation framework for procedures that measure the sum of airborne particles and vapour (not phase‑separated results). Applicable to single substances (e.g., toluene diisocyanate, diethanolamine, ethylene glycol, tributylphosphate) and complex mixtures (metalworking fluids, bitumen fumes).
- Sampler classification:
- Type A - vapour collected on a sorbent bed.
- Type B - vapour collected on an impregnated filter.
- Other options (denuders, impingers) are discussed in Annex B.
- Sampler and pump requirements:
- Samplers must meet general performance criteria (referenced to EN 13205‑1 and ISO 22065).
- Airflow stability: flow must be measured over the whole sampling period and may not deviate by more than 5% (ISO 13137).
- Back pressure must not exceed pump test limits unless validated for the sampling period.
- Connecting parts must be inert and minimize internal volume to avoid adsorption or reaction.
- Pumps shall conform to ISO 13137.
- Measuring procedure elements:
- Sampling must target the inhalable particle fraction (ISO 7708).
- Methods must include detailed sampling procedure, analytical procedure, storage/handling, expanded uncertainty, and known interferences.
- Extraction modes: joint extraction (all substrates extracted together) or separate extraction (substrates extracted separately and summed).
- Test methods and validation:
- Spiking and recovery tests, storage stability, transfer behaviour and uncertainty estimation are specified (see Clauses 8–9 and Annex C).
- Annex A explains the physical behaviour of mixed‑phase aerosols; Annex B gives sampling approach examples.
Practical applications
- Validating and demonstrating performance of mixed‑phase samplers and laboratory methods for workplace exposure monitoring.
- Measurement of hazards where a chemical exists in both particle and vapour phases (e.g., isocyanates, amines, semi‑volatile organics, metalworking fluids).
- Use in occupational hygiene programs, exposure assessment, compliance testing, and method development.
Who should use this standard
- Occupational hygienists and industrial safety professionals
- Sampler and pump manufacturers
- Analytical laboratories validating sampling/analysis procedures
- Method developers, regulators and accreditation bodies
Related standards (key references)
- ISO 20581 (general requirements for measurement procedures)
- ISO 13137 (pumps for personal sampling)
- ISO 7708 (particle size fraction definitions)
- ISO 22065 (pumped samplers - gases and vapours)
- EN 13205‑1 (sampler performance for airborne particles)
Keywords: ISO 23861:2022, workplace air, mixed‑phase sampler, airborne particles and vapour, measuring procedures, sampler evaluation, occupational hygiene.