Abstract

Diisocyanates are occupational contaminants and known sensitizers causing irritation (skin and respiratory tract) as well as occupational asthma. Because of their physicochemical properties (semi-volatile and high reactivity) and low occupational limits, diisocyanate exposure evaluation is still a challenge nowadays for industrial hygienists and laboratories. The objective of this study was to compare the methylene diphenyl diisocyanate (MDI) concentrations measured by five methods using different collection or derivatization approaches in an oriented-strand board (OSB) factory. The methods used were: OSHA 47 (filter, 1-(2-pyridyl)piperazine) (OSHA), Asset EZ4-NCO (denuder and filter, dibutylamine) (Asset), Iso-Chek (double-filter, 9-(N-methylaminomethyl) anthracene and 1,2-methoxyphenylpiperazine), DAN (filter, 1,8-diaminonaphthalene), and CIP10 (centrifugation, 1,2-methoxyphenylpiperazine). Real-time monitoring of particle concentration and size distribution was performed to explain the potential bias between methods. The comparison study was performed over 3 consecutive days, generating at least 18 replicates for each of the 5 methods. The results of each methods were compared using linear mixed effect modeling. Compared to Asset, which yielded the highest concentrations overall, the OSHA method provided the smallest bias with −18% (95% CI [-61;24]) (not significant) for MDI monomer and the DAN method provided the smallest bias with −30 (95% CI [–70;9]) (not significant) for Total Reactive Isocyanate Group (TRIG). The CIP10 and Iso-Chek methods provided the largest biases for MDI monomer (–83% (95% CI [–115;–51]) and −78% (95% CI [–110;–46]), respectively) as well as for TRIG (–87% (95% CI [–120;–55]) and −75% (95% CI [–107;–44]), respectively). The underestimations of the CIP10 and Iso-Chek were explained by its inefficient sampling principle for fines particles and the use of a non-impregnated filter to collect aerosol MDI, respectively. This study confirms that impregnated filter, including denuding device such as the Asset EZ4-NCO sampler, collects the MDI-coated wood particles and MDI vapor with similar efficiency. It also demonstrates for the first time in this type of MDI emission a significant agreement for TRIG concentration between the DAN method in the impregnated filter configuration and an international standard one such as Asset.

摘要

二异氰酸酯是职业污染物，是引起刺激（皮肤和呼吸道）以及职业性哮喘的已知敏化剂。由于其理化特性（半挥发性和高反应性）和较低的职业限制，对当今的工业卫生学家和实验室而言，二异氰酸酯的暴露评估仍然是一个挑战。这项研究的目的是比较定向链板（OSB）工厂中使用不同收集或衍生化方法通过五种方法测得的亚甲基二苯基二异氰酸酯（MDI）浓度。使用的方法是：OSHA 47（过滤器，1-（2-吡啶基）哌嗪）（OSHA），Asset EZ4-NCO（去核剂和过滤器，二丁胺）（资产），Iso-Chek（双过滤器，9-（N -甲基氨基甲基）蒽和1,2-甲氧基苯基哌嗪），DAN（过滤器，1,8-二氨基萘），CIP10（离心分离，1,2-甲氧基苯基哌嗪）。进行了颗粒浓度和粒度分布的实时监控，以解释方法之间的潜在偏差。连续3天进行了比较研究，这5种方法中的每一种均至少产生18次重复。使用线性混合效应模型比较了每种方法的结果。与资产总浓度最高的资产相比，OSHA方法为MDI单体提供的最小偏差为−18％（95％CI [-61; 24]）（不显着），而DAN方法提供的最小偏差为-总反应性异氰酸酯基（TRIG）为30（95％CI [–70; 9]）（不重要）。CIP10和Iso-Chek方法为MDI单体提供了最大偏差（–83％（95％CI [–115; –51]）和−78％（95％CI [–110; –46]），以及TRIG（分别为–87％（95％CI [–120; –55]）和−75％（95％CI [–107; –44]））。CIP10和Iso-Chek的低估是由于它们对微粒的采样原理效率低下以及使用非浸渍过滤器收集气溶胶MDI所致。这项研究证实了浸渍过滤器，包括诸如Asset EZ4-NCO采样器之类的剥皮装置，可以以类似的效率收集涂覆MDI的木屑颗粒和MDI蒸气。它还首次证明了在这种类型的MDI排放中，浸渍过滤器配置中的DAN方法与国际标准（例如Asset）之间的TRIG浓度具有显着的一致性。CIP10和Iso-Chek的低估是由于它们对微粒的采样原理效率低下以及使用非浸渍过滤器收集气溶胶MDI所致。这项研究证实了浸渍过滤器，包括诸如Asset EZ4-NCO采样器之类的剥皮装置，可以以类似的效率收集涂覆MDI的木屑颗粒和MDI蒸气。它还首次证明了在这种类型的MDI排放中，浸渍过滤器配置中的DAN方法与国际标准（例如Asset）之间的TRIG浓度具有显着的一致性。CIP10和Iso-Chek的低估是由于它们对微粒的采样原理效率低下以及使用非浸渍过滤器收集气溶胶MDI所致。这项研究证实了浸渍过滤器，包括诸如Asset EZ4-NCO采样器之类的剥皮装置，可以以类似的效率收集涂覆MDI的木屑颗粒和MDI蒸气。它还首次证明了在这种类型的MDI排放中，浸渍过滤器配置中的DAN方法与国际标准（例如Asset）之间的TRIG浓度具有显着的一致性。以相似的效率收集涂覆有MDI的木屑颗粒和MDI蒸气。它还首次证明了在这种类型的MDI排放中，浸渍过滤器配置中的DAN方法与国际标准（例如Asset）之间的TRIG浓度具有显着的一致性。以相似的效率收集涂覆有MDI的木屑颗粒和MDI蒸气。它还首次证明了在这种类型的MDI排放中，浸渍过滤器配置中的DAN方法与国际标准（例如Asset）之间的TRIG浓度具有显着的一致性。