Because of the semi-volatile nature of diisocyanates (being airborne in both physical vapor and particulate phases), their high reactivity and low occupational exposure limits, diisocyanate exposure evaluation has been challenging for industrial hygienists and laboratories. The objective of this study was to compare the toluene diisocyanate (2,4 and 2,6 isomers, TDI) concentration measured by five methods in a flexible polyurethane foam factory using different collection or derivatization approaches. The methods used were: OSHA 42 modified (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). Particle real-time monitoring for concentration and size distribution was performed in parallel to improve the understanding of the potential bias between methods. The comparison study was performed over 3 days, providing 18 replicates for each of the 5 methods. Isocyanate concentrations collected for each sampling method were compared using linear mixed effect modeling. Compared to OSHA, which yielded the highest concentrations overall, the Asset and DAN methods provided the smallest biases (-29% (95% CI [-52;-6]) and -45% (95% CI [-67;-23]), respectively), while the CIP10 and Iso-Chek methods provided the largest biases (-82% (95% CI [-105;-66]) and -96% (95% CI [-118;-75]), respectively). The substantial bias of Iso-Chek and CIP10 seemed to be explained by the predominance of TDI in the form of sub-micron particles that were inadequately captured by these two methods due to their sampling principle, which are particle filtration without derivatizing agent and centrifugation respectively. Asset and DAN performance seemed to decrease as the sampling time increased. While DAN's bias could be related to a reagent deficiency on the filter, the disparities between OSHA and Asset, both considered as reference methods, highlight the fact that the mechanisms of collection, derivation and extraction do not seem to be completely controlled. Finally, an upward trend has been observed between concentrations of particles below 300 nm in size and concentration levels of TDI. It has also been observed that TDI levels increased with the TDI foam index produced at the facility.

中文翻译：

---

在聚氨酯泡沫塑料厂现场比较OSHA 42，Asset EZ4-NCO，Iso-Chek，DAN和CIP10方法测量甲苯二异氰酸酯（TDI）的方法。

由于二异氰酸酯的半挥发性质（在空气中以物理气相和颗粒相两种形式传播），它们的高反应活性和低职业暴露极限，因此对工业卫生学家和实验室而言，二异氰酸酯的暴露评估一直是一项挑战。这项研究的目的是比较使用不同收集或衍生化方法在柔性聚氨酯泡沫塑料厂中通过五种方法测量的甲苯二异氰酸酯（2,4和2,6异构体，TDI）浓度。使用的方法是：经OSHA 42修饰的（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）和CIP10（离心分离，1,2-甲氧基苯基哌嗪）。并行执行浓度和尺寸分布的粒子实时监控，以增进对方法之间潜在偏差的了解。对比研究进行了3天，为5种方法中的每一种提供18个重复样品。使用线性混合效应模型比较每种采样方法收集的异氰酸酯浓度。与OSHA（总浓度最高）相比，Asset和DAN方法提供的偏差最小（-29％（95％CI [-52; -6]）和-45％（95％CI [-67; -23] ]）），而CIP10和Iso-Chek方法提供的偏差最大（-82％（95％CI [-105; -66]）和-96％（95％CI [-118; -75]） ， 分别）。Iso-Chek和CIP10的显着偏差似乎是由于TDI的优势在于亚微米颗粒的形式，由于它们的采样原理，这两种方法未能充分捕获亚微米颗粒，它们分别是没有衍生剂的颗粒过滤和离心分离。资产和DAN的性能似乎随着采样时间的增加而降低。尽管DAN的偏见可能与过滤器上的试剂不足有关，但OSHA和Asset之间的差异（均被视为参考方法）突显了一个事实，即似乎并未完全控制收集，衍生和提取的机制。最后，在尺寸小于300 nm的颗粒浓度与TDI浓度水平之间观察到上升趋势。