title: Comparison between the ASSET EZ4 NCO and Impinger Sampling Devices for Aerosol Sampling of 4,4'-Methylene Diphenyl Diisocyanate in Spray Foam Application.
abstract: 4,4'-methylene diphenyl diisocyanate (MDI) aerosol exposure evaluation in spray foam insulation application is known to be a challenge. Current available techniques are either not user-friendly or are inaccurate or are not validated for this application. A new sampler has recently been developed to address the user-friendliness issues with other samplers: the ASSET EZ4-NCO, but the use of this sampler in spray foam insulation applications has not been demonstrated or validated. Because of this, the current work was undertaken to provide a comparison of the ASSET sampler with an impinger method, considered to be the best available method in the context of spray foam insulation, and hence the pertinence of comparing this sampler to an impinger method, considered to be the best available method for measuring MDI monomer and oligomers for this particular application. Liquid chromatography coupled with tandem mass spectrometry method for MDI monomer and oligomer analysis was implemented based on the Supelco literature. It allows the analysis of MDI-dibutylamine (DBA) and MDI 3-ring-DBA with a minimum reported value of 5ng ml(-1), a dynamic range of 5-140ng ml(-1), precision <15% and accuracy >80%. This method was used to quantify MDI aerosols collected with the ASSET sampler in an MDI spray foam environment in parallel with the toluene/MOPIP impinger reference method. The ASSET sampler significantly underestimated the levels of MDI monomer and oligomers when compared to the reference method. The estimated bias was 72% (95% confidence interval [CI] 54-89%) for the monomer and 96% (95% CI 76-115%) for the oligomers. These results demonstrate the importance of evaluating each new sampler for each isocyanate application prior to a formal worker exposure evaluation.
authors: 1.Institut de recherche Robert-Sauvé en santé et en sécurité du travail, 505 boul, De Maisonneuve Ouest, Montréal, Québec, Canada H3A 3C2 2.Chemistry Department, Université du Québec à Montréal, 2101 rue Jeanne-Mance, Montréal, Québec, Canada H3C 3P8.
authors: Silvia
authors: S
authors: Puscasu
authors: 1.Institut de recherche Robert-Sauvé en santé et en sécurité du travail, 505 boul, De Maisonneuve Ouest, Montréal, Québec, Canada H3A 3C2.
authors: Simon
authors: S
authors: Aubin
authors: 1.Institut de recherche Robert-Sauvé en santé et en sécurité du travail, 505 boul, De Maisonneuve Ouest, Montréal, Québec, Canada H3A 3C2.
authors: Yves
authors: Y
authors: Cloutier
authors: 1.Institut de recherche Robert-Sauvé en santé et en sécurité du travail, 505 boul, De Maisonneuve Ouest, Montréal, Québec, Canada H3A 3C2.
authors: Philippe
authors: P
authors: Sarazin
authors: 2.Chemistry Department, Université du Québec à Montréal, 2101 rue Jeanne-Mance, Montréal, Québec, Canada H3C 3P8.
authors: Huu
authors: H
authors: Van Tra
authors: 1.Institut de recherche Robert-Sauvé en santé et en sécurité du travail, 505 boul, De Maisonneuve Ouest, Montréal, Québec, Canada H3A 3C2 sebastien.gagne@irsst.qc.ca.
authors: Sébastien
authors: S
authors: Gagné
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000395:Air Pollutants, Occupational / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods; D004784:Environmental Monitoring / Q000295:instrumentation*; D006801:Humans; D017953:Isocyanates / Q000032:analysis*; D016273:Occupational Exposure; D053719:Tandem Mass Spectrometry / Q000379:methods; D001559:Benzhydryl Compounds
chemical_list: D000336:Aerosols; D000395:Air Pollutants, Occupational; D017953:Isocyanates; C005969:4,4'-diphenylmethane diisocyanate; D001559:Benzhydryl Compounds
keywords: ASSET EZ4-NCO sampler; MDI; denuder; impinger; isocyanate