Why and How to Perform a Standardized Air Sampling

Detailed Background and Methods

Why conduct air sampling?

Air sampling in workplaces is essential to assess atmospheric contaminants, protect worker health, ensure regulatory compliance (keeping pollutants below occupational exposure limits), and guide preventive actions or controls.

Pollutant Types & Sampling Strategies:

• Dust & Fibers: Typically active sampling using filters and devices like cyclones or impactors, to collect inhalable or respirable fractions. For example, asbestos is sampled using a 25 mm cassette with a flow around 8 L/min.

• Gases, Vapors & VOCs:

  • Active: Pumping air through adsorbent tubes or impingers (e.g. charcoal for solvents, DNPH for aldehydes). Flow rates vary (from ~50 mL/min to 1 L/min).

  • Passive: Diffusive badges with sorbents (e.g. activated charcoal, DNPH) worn by workers. Ideal for long-duration exposure, though less sensitive for short-term peaks.

• Bioaerosols:

  • Impactors on agar: Air is aspirated onto a petri dish to grow colonies (measuring viable counts).

  • Impingers (liquid): Trap airborne organisms in a liquid for culture or molecular analysis.

  • Filters: Collect bioaerosols on gelatin or polycarbonate filters for microscopy or DNA analysis.

  • Spore traps: Airborne particles adhere to a slide for microscopic analysis.

Choice depends on whether viability or total presence (incl. non-viable) needs quantification.

Choosing Equipment: Criteria & Standards

Key considerations:

• Target contaminant type → determines the sampling medium and device (filter, sorbent tube, impinger, badge, etc.)

• Flow rate requirements → must match device specs for size fractioning and detection sensitivity

• Sampling duration → sufficient for quantifiable samples without saturating the medium

• Sampling media → filters (PVC, quartz, etc.), tubes with adsorbents, impregnated filters, liquid impingers, badges

• Standards and regulations → follow national (e.g., NF X, INRS) or international methods (ISO, NIOSH, OSHA, EN 689)

• Ergonomics & field constraints → equipment should be compact, quiet, compliant with environments (e.g. ATEX zones)

In short: select the right tool for the contaminant, respecting flow, duration, media, and standards to obtain reliable and representative results.

Field Procedure: Preparation, Sampling & Post-Analysis

Preparation:

• Plan logistics (what, where, how long, who)

• Gather materials (pumps, media, calibration tools, labels, etc.)

• Prepare blanks for contamination control

• Calibrate pumps under conditions simulating real sampling

In the field:

• Attach collector to worker at breathing zone or set up ambient sample

• Start and monitor sampling; note start time

• Record environmental conditions and worker's tasks; note end time

• Perform a final calibration check; label and seal samples

• Transport samples properly (some must be refrigerated or kept dark) with correct documentation for chain-of-custody

Laboratory analysis & interpretation:

• Samples analyzed by appropriate methods

• Concentrations calculated and compared to occupational limits (e.g. VLEP‑8h or short-term limits)

• If limits are exceeded, corrective actions must be taken

• Apply uncertainty considerations; near-limit results require cautious interpretation

• For substances without limits, use guidance values or ALARA principle

Integration into HSE/QHSE Management

• Initial risk assessment: Sampling data feed into risk documentation and help classify exposure levels

• Ongoing monitoring: Regulations often require annual sampling; internal schedules may include quarterly or semi-annual checks

• Continuous improvement: Use results to improve controls and verify their effectiveness

• Traceability: Archive data internally and submit to national databases (e.g. SCOL in France); useful for audits, health claims, ISO 45001 compliance

• HSE performance tracking: Sampling indicators (e.g. % compliant workstations) support quality and safety goals; they also play a role in contamination control, especially in cleanroom environments

• Training and culture: Teaching staff proper use and handling of sampling tools reinforces a prevention culture

SKC Equipment Compatibility (Examples)

SKC offers a comprehensive range tailored to these sampling needs:

• Pumps: AirChek® series (AirChek 52, AirChek TOUCH, Sidekick – ATEX)

• Filters & cassettes: 25 mm and 37 mm, pre-loaded and compliant with standards

• Cyclones, impactors: For respirable/inhalable fraction, multi-stage impactors

• Sorbent tubes & cartridges: Charcoal, silica, Tenax, DNPH, OVS—provided with equivalent method info

• Impingers & badges: Liquid impingers, passive badges like UMEx 100 and others

• Bioaerosol samplers: BioSampler®, BioStage, VersaTrap, Air‑O‑Cell, Button Sampler for endotoxin

• Accessories: Flow calibrators, tripods, data tracking tools, etc.

These components are designed for compatibility and reliability in multi-contaminant sampling setups.