ISO 17091:2013

Overview - ISO 17091:2013 (Workplace air, hydroxides, ion chromatography)

ISO 17091:2013 defines a validated analytical method for workplace air monitoring of lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH) and calcium dihydroxide [Ca(OH)2]. The procedure collects particulate hydroxides on a filter (personal or static sampling) and determines the corresponding cations (Li+, Na+, K+, Ca2+) by suppressed ion chromatography. The method is applicable to the inhalable fraction of aerosols (as defined in ISO 7708) and provides time‑weighted average mass concentrations for occupational exposure assessment.

Key topics and technical requirements

• Sampling approach: personal sampling of the inhalable fraction and static (area) sampling using filter collection. Guidance on sampling position, preparation, transport and sampler wall deposits is included.
• Analytical principle: measurement of corresponding cations by suppressed ion chromatography after filter extraction; results reported as equivalent hydroxide mass concentrations.
• Performance and ranges:
  • Mass per sample: Li: 0.005 mg to ≥2.5 mg; Na, K, Ca: 0.01 mg to ≥5 mg.
  • Working concentration range (1 m3 air sample): approximately 0.002 mg·m−3 to ≥20 mg·m−3 for each hydroxide.
  • For small samples (30 L), the lower working limit is about 0.1 mg·m−3.
• Limitations: the method does not distinguish between hydroxides and their corresponding salts if both are present. When cations are present only as hydroxides, results are specific for the basic compounds; otherwise reported values represent the maximum possible hydroxide concentration.
• Quality control & method performance: procedures for detection/quantification limits, bias, precision, measurement uncertainty, interferences, and storage stability are specified. Annexes cover filter materials, sampler wall deposits, and temperature/pressure corrections.

Practical applications & who uses ISO 17091

• Industrial hygienists and occupational health professionals assessing worker inhalation exposure to hydroxide aerosols.
• Analytical laboratories performing workplace air monitoring using ion chromatography.
• Employers and safety managers in industries handling LiOH, NaOH, KOH or Ca(OH)2 (battery manufacture, chemical processing, metal treatment).
• Regulatory and certification bodies verifying compliance with occupational exposure limits and control measures.

Related standards

• ISO 7708 - Particle size fraction definitions for health‑related sampling (inhalable fraction)
• ISO 1042 - Laboratory glassware (volumetric flasks)
• ISO 13137 (workplace pumps for personal sampling) and EN 13205‑1 (particle instrument performance) are referenced for sampling equipment and performance assessment.

Keywords: ISO 17091, workplace air monitoring, lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium dihydroxide, suppressed ion chromatography, inhalable fraction, occupational exposure, air sampling, analytical method.