ISO 8518:2022

Overview

ISO 8518:2022 specifies validated laboratory procedures for measuring particulate lead and lead compounds in workplace air using flame and electrothermal atomic absorption spectrometric (AAS) methods. The standard covers sampling (personal and static/area), sample dissolution (hot-plate digestion, microwave-assisted digestion, or ultrasonic extraction), instrumental analysis, detection capability ranges, and quality control for time-weighted average (TWA) mass concentrations of inhalable particles (per ISO 7708) and other health-related fractions as needed.

Key topics and requirements

• Scope and purpose: Determination of TWA mass concentration of particulate lead and lead compounds in workplace atmospheres for occupational exposure assessment.
• Sampling types: Personal sampling of the inhalable fraction and static (area) sampling; guidance on sampler selection, sampling position, flow rate, blanks, transport and storage.
• Sample dissolution options:
  • Hot-plate digestion
  • Microwave-assisted digestion
  • Ultrasonic extraction (validated for laboratory-generated lead-fume filter samples at approx. 20 µg to 100 µg lead per sample)
  • Use a more vigorous dissolution if target lead compounds are insoluble with the listed procedures.
• Analytical methods:
  • Flame AAS - suitable for approximately 1 µg to 200 µg lead per sample (without dilution).
  • Electrothermal AAS - suitable for approximately 0.01 µg to 0.5 µg lead per sample (without dilution).
• Measurement strategy: Guidance on assessment strategy, selection of measurement conditions (screening, worst-case, periodic measurements), and how sampling choice affects applicable air concentration range.
• Quality assurance: Reagent/media blanks, spiked samples and duplicates, certified reference materials, external quality assessment, and determination of instrumental/method detection and quantification limits.
• Special considerations: Treatment of sampler wall deposits (informative Annex B), temperature/pressure corrections, and reporting requirements.

Applications and users

ISO 8518:2022 is intended for:

• Industrial hygienists and occupational health professionals conducting workplace air monitoring for lead exposure.
• Analytical laboratories performing trace metal analysis of air filter samples.
• Regulatory and enforcement agencies assessing compliance with occupational exposure limits.
• Employers in industries with potential lead exposure (mining, metal refining, battery manufacture, construction) to verify control measures.

Practical benefits include standardized workflows for sample preparation and AAS analysis, defined detection ranges for method selection, and QA practices that improve comparability and legal defensibility of exposure data.

Related standards

• ISO 7708 - Definition of particle size fractions (inhalable fraction) used in sampling guidance referenced by ISO 8518.