ISO 17734-1:2013

ISO 17734-1:2013 - Overview

ISO 17734-1:2013 specifies a validated analytical approach for the sampling and analysis of airborne isocyanates in workplace air using derivatization with di-n‑butylamine (DBA) and detection by liquid chromatography–mass spectrometry (LC‑MS). The standard covers both gas‑phase and particle‑bound isocyanates, including monofunctional isocyanates (ICA, MIC, EIC, PIC, BIC, PhI), common diisocyanates (HDI, TDI, MDI, NDI, IPDI, HMDI) and multifunctional/oligomeric forms (polymeric MDI adducts, biuret, isocyanurate, allophanate, prepolymers).

Key technical topics and requirements

• Sampling principle: Air is drawn through a midget impinger containing DBA in toluene followed by a glass-fibre filter; solvent‑free sampling using DBA‑impregnated filters is an alternative for long sampling times.
• Derivatization: Isocyanates are converted to stable DBA derivatives during sampling to prevent secondary reactions and losses.
• Instrumentation: Analysis is performed by LC‑MS / LC‑MS/MS for selective identification and quantification. A nitrogen‑sensitive detector (LC‑CLND) is referenced for preparing reference solutions.
• Standards and reagents: Use of deuterium‑labelled isocyanate‑DBA internal standards is recommended for accurate quantification and to control recovery.
• Performance characteristics: Instrumental detection limits ≈ 5 nmol/sample for aliphatic isocyanates and 0.2 nmol/sample for aromatic isocyanates. For a 15 L air sample this equals about 0.6 ng·m‑3 (HDI) and 0.02 ng·m‑3 (TDI). Useful range for TDI (5 L sample) is about 0.001 µg·m‑3 to 200 mg·m‑3.
• Data handling: Guidance on identification, calibration curves, quantification, interferences and uncertainty assessment is included.

Practical applications and who uses this standard

ISO 17734-1 is intended for:

• Industrial hygienists and occupational health laboratories monitoring worker exposure to isocyanates.
• Environmental and analytical laboratories performing air monitoring in manufacturing, spray‑coating, foam production and polyurethane (PUR) processing.
• Regulatory bodies and consultants assessing compliance with occupational exposure limits (OELs) and investigating incidents (e.g., thermal degradation of PUR).
• Manufacturers concerned with emissions profiling and process control.

The method is especially valuable where very low detection levels, speciation of multiple isocyanates, or identification of degradation products are required.

Related standards

• ISO 17734-2: Complementary method for amines and aminoisocyanates (DBA + ethyl chloroformate).
• ISO 5725-2: Accuracy (trueness and precision) of measurement methods.
• ISO 16200-1: Sampling and analysis of volatile organic compounds (pumped sampling).

Keywords: ISO 17734-1:2013, isocyanates, dibutylamine (DBA), LC‑MS, workplace air monitoring, sampling and analysis, TDI, HDI, polyurethane.