SIST ISO 16702:2012 PDF

Overview

ISO 16702:2007 - "Workplace air quality - Determination of total organic isocyanate groups in air using 1-(2-methoxyphenyl)piperazine and liquid chromatography" - provides a standardized method for sampling and analysing airborne organic isocyanates (NCO groups) in workplace atmospheres. The method uses 1-(2‑methoxyphenyl)piperazine (MP) to derivatize isocyanates into stable urea derivatives, which are quantified by liquid chromatography (HPLC) with electrochemical (EC) and ultraviolet/visible (UV/vis) detection. ISO 16702:2007 covers mono‑ and di‑isocyanates as well as oligomeric/polymeric isocyanates (polyisocyanates) and is suitable for personal monitoring and fixed-location sampling.

Key Topics and Requirements

• Scope: Measurement of total isocyanate groups (monomers, oligomers, prepolymers) in workplace air; suitable for MDI, TDI, HDI and other common isocyanates (e.g., IPDI, HMDI, NDI).
• Derivatization reagent: MP (1-(2‑methoxyphenyl)piperazine) reacts with NCO to form stable urea derivatives for HPLC analysis.
• Detection:
  • UV/vis for isocyanates where analytical standards exist (monomer quantification).
  • Electrochemical (EC) detection for polymeric isocyanates (oxidises the common methoxy group on MP), enabling quantification when polymer standards are unavailable.
• Sampling methods:
  • Filters recommended for vapour-phase isocyanates.
  • Impinger + filter combination recommended for aerosols.
  • Designed primarily for personal (breathing zone) sampling; adaptable for fixed-location monitoring.
• Performance and range:
  • Sampling periods: ~0.5 min to 8 h.
  • Typical measurement range: ~0.1 µg/m3 to 140 µg/m3 for a 15 L sample volume.
  • Typical qualitative/quantitative detection limits (EC): ~0.07 µg/m3 and ~0.3 µg/m3 (for a 15 L sample).
• Quality elements: Calibration, field blanks, sampling efficiency, uncertainty assessment and stability checks are defined; method references ISO 5725‑2 and approaches from ISO/IEC Guide 98:1995.

Applications and Who Uses It

• Occupational hygiene and exposure assessment: Determining time‑weighted average isocyanate exposure to evaluate compliance with occupational exposure limits and to manage respiratory sensitiser risks.
• Industries: Polyurethane production, paints and coatings, adhesives, foam manufacture, and processes producing thermal degradation products (e.g., laser cutting, flame bonding).
• Users: Industrial hygienists, analytical laboratories, employers’ health & safety teams, regulatory bodies, and researchers conducting workplace air monitoring.

Related Standards (if applicable)

• ISO 5725‑2 - Accuracy (trueness and precision) of measurement methods and results.
• ISO/IEC Guide 98:1995 - Uncertainty of measurement (referenced approaches).
• MDHS 25/3 - UK method on which this ISO method is based (informative reference).

Keywords: ISO 16702:2007, workplace air quality, isocyanate monitoring, MP derivatization, HPLC, electrochemical detection, UV detection, personal air sampling, polyisocyanates, occupational hygiene.