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Total Reactive Isocyanate Group (TRIG) Measurement: A Commentary
Glen McConnachie1, Paul Johnson1
1Health and Safety Executive Science and Research Centre, Harpur Hill, Buxton, Derbyshire SK17 9JN, UK.
Annals of Work Exposures and Health
|March 3, 2023
Summary
Occupational asthma caused by airborne isocyanates is preventable. Measuring total reactive isocyanate groups (TRIG) offers a more comprehensive assessment of exposure than individual compounds.
Area of Science:
- Occupational health
- Industrial hygiene
- Toxicology
Background:
- Airborne isocyanates are a primary cause of occupational asthma, a preventable allergic respiratory disease.
- Isocyanates act as respiratory sensitizers, leading to persistent symptoms even after exposure ceases.
- Occupational exposure limits (OELs) for isocyanates are often based on total reactive isocyanate groups (TRIG).
Purpose of the Study:
- To review and compare methods for measuring TRIG in workplace air.
- To highlight the advantages of TRIG measurement over individual isocyanate analysis.
- To discuss limitations and potential future developments in TRIG measurement techniques.
Main Methods:
- Review of existing standardized methods (e.g., ISO) for isocyanate detection.
- Analysis of methods applicable to TRIG determination, including modifications of individual compound methods.
- Consideration of techniques for quantifying complex isocyanate mixtures.
Main Results:
- TRIG measurement simplifies exposure calculations and data comparison.
- TRIG analysis reduces the risk of underestimating exposure to diverse isocyanate forms (monomers, prepolymers, oligomers).
- Existing methods vary in their direct applicability to TRIG determination, often requiring adaptation.
Conclusions:
- Measuring TRIG is advantageous for assessing occupational exposure to isocyanates, especially in complex mixtures.
- Standardized methods exist, but modifications may be needed for accurate TRIG quantification.
- Further developments in TRIG measurement techniques are needed to address evolving workplace exposures.
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