Federal Institute for Occupational Safety and Health (BAuA), Division 4 - Hazardous Substances and Biological Agents, Unit 4.1 - Exposure Scenarios, Friedrich-Henkel-Weg 1, Dortmund, Germany.
Ann Work Expo Health. 2021 Oct 9;65(8):893-907. doi: 10.1093/annweh/wxab021.
Diisocyanates are a chemical group that are widely used at workplaces in many sectors. They are also potent skin- and respiratory sensitizers. Exposure to diisocyanates is a main cause of occupational asthma in the European Union. To reduce occupational exposure to diisocyanates and consequently the cases of diisocyanate-induced asthma, a restriction on diisocyanates was recently adopted under the REACH Regulation in the European Union.
A comprehensive evaluation of the data on occupational exposure to the most important diisocyanates at workplaces was made and is reported here. The diisocyanates considered are methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI), accounting for more than 95% of the market volume in the EU. The exposure assessment is based on data from Chemical Safety Reports (CSRs) of REACH Registration Dossiers, workplace air monitoring data from Germany, from the UK Health and Safety Executive (HSE), and literature data relevant for the EU, and the USA.
Occupational exposure to diisocyanates is particularly relevant in: (i) C.A.S.E. applications (Coatings, Adhesives, Sealants, Elastomers), (ii) production of polyurethanes (PUs) (e.g. slab-stock foam), (iii) handling of partly uncured PU products (e.g. cutting, demoulding, spray application of foam), and (iv) when diisocyanates/PUs are heated (e.g. hot lamination, foundry applications/casting forms). Ranking of the reported data on inhalation to diisocyanate exposure at workplaces (maximum values) leads to following order: (i) HDI and its oligomers in coatings, (ii) MDI in spray foam applications, (iii) TDI in manufacture of foam, (iv) TDI in manufacture of PUs and PU composite materials, (v) TDI in adhesives, (vi) MDI in adhesives, (vii) MDI in manufacture of PUs and PU composite materials, (viii) TDI in coatings, (ix) MDI in manufacture of foam, and (x) HDI in adhesives.
二异氰酸酯是一类在许多行业的工作场所广泛使用的化学物质，同时也是强力的皮肤和呼吸道致敏物。在欧盟，接触二异氰酸酯是职业性哮喘的主要原因。为了减少职业性接触二异氰酸酯并由此引发的二异氰酸酯诱导性哮喘，最近根据《欧盟 REACH 法规》对二异氰酸酯实施了限制。
对工作场所最重要的二异氰酸酯的职业接触数据进行了全面评估，并在此报告。所考虑的二异氰酸酯为亚甲基二苯基二异氰酸酯（MDI）、甲苯二异氰酸酯（TDI）和六亚甲基二异氰酸酯（HDI），占欧盟市场总量的 95%以上。暴露评估基于 REACH 注册卷宗中的化学安全报告（CSR）、德国的工作场所空气监测数据、英国健康与安全执行局（HSE）的数据以及与欧盟和美国相关的文献数据。
二异氰酸酯的职业接触尤其与以下方面相关：（i）CASE 应用（涂料、胶粘剂、密封剂、弹性体），（ii）生产聚氨酯（PU）（例如块状泡沫），（iii）处理未完全固化的 PU 产品（例如切割、脱模、泡沫喷涂应用），以及（iv）当二异氰酸酯/PU 被加热时（例如热层压、铸造应用/铸造模具）。对工作场所二异氰酸酯吸入暴露的报告数据（最大值）进行排序，结果如下：（i）涂料中二异氰酸酯及其低聚物，（ii）喷涂泡沫应用中的 MDI，（iii）泡沫生产中的 TDI，（iv）PU 及 PU 复合材料生产中的 TDI，（v）胶粘剂中的 TDI，（vi）胶粘剂中的 MDI，（vii）PU 及 PU 复合材料生产中的 MDI，（viii）涂料中的 TDI，（ix）泡沫生产中的 MDI，以及（x）胶粘剂中的 HDI。
