Measurements of cellulose nanofiber emissions and potential exposures at a production facility

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. [Display omitted] •The release of cellulose nanofibers was quantified at a production facility.•The released cellulose nanofibers were effectively removed by ventilation systems.•Pyrolysis-gas chromatography–mass spectrometry can detect cellulose nanofibers.