Cellulose nanomaterials (CNs) are emerging advanced materials with many unique properties and growing commercial significance. A life-cycle risk assessment and environmental health and safety roadmap identified potential risks from inhalation of powdered CNs in the workplace as a key gap in our understanding of safety and recommended addressing this data gap to advance the safe and successful commercialization of these materials. Here, we (i) summarize the currently available published literature for its contribution to our current understanding of CN inhalation hazard and (ii) evaluate the quality of the studies for risk assessment purposes using published study evaluation tools for nanomaterials to assess the weight of evidence provided. Our analysis found that the quality of the available studies is generally inadequate for risk assessment purposes but is improving over time. There have been some advances in knowledge about the effects of short-term inhalation exposures of CN. The most recent in vivo studies suggest that short-term exposure to CNs results in transient inflammation, similarly to other poorly soluble, low toxicity dusts such as conventional cellulose, but is markedly different from fibers with known toxicity such as certain types of multiwalled carbon nanotubes or asbestos. However, several data gaps remain, and there is still a lack of understanding of the effects from long-term, low-dose exposures that represent realistic workplace conditions, essential for a quantitative assessment of potential health risk. Therefore, taking precautions when handling dry forms of CNs to avoid dust inhalation exposure is warranted.

Commercialization of cellulose nanomaterials (CNs) is rapidly advancing, to the benefit of many end-use product sectors, and providing information about the safe manufacturing and handling for CNs is a priority. Safety Data Sheets (SDS) are required for industrially produced materials to communicate information on their potential health, fire, reactivity, and environmental hazards, and to provide recommendations on how to safely work with these materials. Cellulose and cellulose pulp, which have widespread commercial end uses, can create nuisance dusts when dried and are required to have SDS. We therefore expect that nanoscale forms of cellulose will also require SDS. This study identifies the currently available SDS information for CNs and highlights existing gaps in our knowledge. With U.S. and international adoption of the Globally Harmonized System (GHS) for Hazard Communication, producers are required to report SDS known data and data gaps. Given the novelty of all nanomaterials, it is preferable to fill these gaps in SDS as a demonstration of our commitment to the safe production and use of these materials. To evaluate the availability of SDS information and prepare for commercialization of CNs, we assessed available safety information for CNs to identify available GHS SDS data, data gaps, and what data need to yet be developed to fully classify CNs according to the GHS. Specifically, we report on the available data and gaps regarding the toxicological profile, environmental characteristics, physical and chemical properties, exposure controls, and personal protection for cellulose nanomaterials, to encourage the development of missing data and advance safe commercialization.