Abstract We evaluated the occupational exposure of cellulose nanofibers (CNFs) at a production facility during 1) the collection of CNF powder produced by drying CNF slurry and 2) the transfer of CNF powder from a large bag to small bags. Airborne CNFs in the work environment were quantified by carbon analysis and pyrolysis-gas chromatography–mass spectrometry (Py-GC–MS), both of which are methods for measuring thermal decomposition products of CNFs. In addition, aerosol particles were measured by the commonly used methods such as real-time aerosol monitoring, gravimetric analysis, and electron microscopy. The release of CNF powder was found during both processes and they were effectively removed by a ventilation system or a fume hood without spreading to the operator's work area. All the measured concentrations were lower than the occupational exposure limits (OELs) for bulk cellulose. Moreover, the CNF concentrations close to the operator's work area measured by Py-GC–MS were less than 2 μg/m3, which is comparable to or lower than the OELs for nanomaterials such as carbon nanotubes and titanium dioxide nanoparticles. This study demonstrated that Py-GC–MS can measure lower concentrations of CNFs than through gravimetric analysis or carbon analysis and is an effective method for quantitatively measuring CNFs in the work environment.

中文翻译：

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生产设施中纤维素纳米纤维排放和潜在暴露的测量

摘要 我们评估了纤维素纳米纤维 (CNF) 在生产设施中的职业暴露情况：1) 收集通过干燥 CNF 浆料产生的 CNF 粉末和 2) 将 CNF 粉末从大袋转移到小袋。通过碳分析和热解-气相色谱-质谱法 (Py-GC-MS) 对工作环境中的空气中 CNF 进行量化，这两种方法都是测量 CNF 热分解产物的方法。此外，通过实时气溶胶监测、重量分析和电子显微镜等常用方法测量气溶胶颗粒。在这两个过程中都发现了 CNF 粉末的释放，它们被通风系统或通风橱有效地去除，而没有扩散到操作员的工作区域。所有测量的浓度都低于散装纤维素的职业接触限值 (OEL)。此外，通过 Py-GC-MS 测量的靠近操作员工作区域的 CNF 浓度小于 2 μg/m3，这与纳米材料（如碳纳米管和二氧化钛纳米粒子）的 OEL 相当或更低。该研究表明，与重量分析或碳分析相比，Py-GC-MS 可以测量更低浓度的 CNF，并且是定量测量工作环境中 CNF 的有效方法。