Overview
ISO 11174:2023 - Workplace air: Determination of particulate cadmium and cadmium compounds - Flame and electrothermal atomic absorption spectrometric method - specifies a validated analytical procedure for measuring the mass concentration of particulate cadmium and cadmium compounds in workplace air. The standard covers sample collection (personal or stationary) for inhalable or respirable fractions (as defined in ISO 7708), sample digestion, and analysis by either flame atomic absorption spectrometry (FAAS) or electrothermal atomic absorption spectrometry (ETAAS).
Key practical points:
- Sample substrates: typical filter or foam samplers for inhalable/respirable fractions.
- Sample digestion: nitric acid procedure (diluted 1+1 then concentrated by heating) validated for a range of cadmium compounds, pigments and glass enamels.
- Analysis: FAAS at 228.8 nm or ETAAS with background correction; hollow cathode or electrodeless discharge lamps are used.
- Validated mass ranges: ETAAS - 10 ng to 600 ng Cd per sample; FAAS - 0.15 µg to 96 µg Cd per sample.
- Warning: cadmium is toxic and a suspected human carcinogen; appropriate PPE and controls are required.
Key Topics and Requirements
- Sampling methodology: Personal or stationary sampling; collection characteristics, flow rate, sampling period, and handling of sampler wall deposits are addressed. Sampling targets either inhalable or respirable fractions (ISO 7708).
- Sample preparation: Defined sample dissolution/digestion (see clause 10.2.2) using nitric acid and controlled evaporation and dilution to produce the test solution.
- Instrumental analysis: Procedures for calibration, preparation of calibration solutions, and measurement by FAAS or ETAAS (including use of matrix modifiers and graphite tube atomization for ETAAS).
- Performance parameters: Instrumental detection limits, working range, method detection limits and validated mass ranges for both techniques.
- Quality and reporting: Requirements reference ISO/IEC 17025 competence, documentation of test report content, and method performance evaluation (precision, detection limits).
- Safety: Explicit warning about cadmium toxicity and requirement for protective measures.
Applications and Users
ISO 11174:2023 is designed for:
- Industrial hygienists and occupational health professionals monitoring worker exposures.
- Analytical laboratories performing workplace air analyses and reporting results in compliance with regulatory or corporate exposure limits.
- Regulatory agencies and safety program managers assessing control measures in industries such as battery manufacturing, metal processing, electronics, pigments, glass enamels, mining, and construction.
- Employers and consultants implementing exposure assessment, compliance monitoring and control validation.
Practical benefits include standardized sampling/analysis, traceable results within validated ranges, and guidance to support exposure assessment and risk management.
Related Standards
- ISO 7708 - Particle size fraction definitions for health-related sampling
- ISO/IEC 17025 - Laboratory competence
- ISO 18158 - Workplace air terminology
- ISO 20581 / ISO 21832 - Workplace air measurement requirements and evaluation of measuring procedures
Keywords: ISO 11174:2023, workplace air, cadmium, cadmium compounds, atomic absorption spectrometry, flame AAS, electrothermal AAS, inhalable respirable sampling, occupational exposure monitoring.
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