Environmental, health & safety (EHS) aspects of cellulose nanofibrils (CNF) and CNF-based products

Increased interest has been expressed towards bio-based nanomaterials, including cellulose nanofibrils (CNF), during the last decade. CNFs have many unique properties, such as high specific surface area and aspect ratio, making them potential for many applications in several industrial sectors, ranging from papermaking and packaging to food, cosmetics and pharmaceuticals. CNFs are of especial interest in paper- and boardmaking as well as in packaging applications, as they can be applied for example as reinforcement agents in the paper/board structure, as rheology modifiers in coating applications and barrier films for packaging purposes. As materials originating from cellulose, the most abundant organic polymer on earth, CNFs can also be considered natural and renewable as well as biodegradable and biocompatible. However, it must be remembered that the nano-specific properties of CNFs, which make them excellent materials for improving the performance of diverse applications, might also have implications on their safety. Generally, the interactions of nanomaterials with living organism and the environment are not well understood. Despite the number of publications on cellulose nanomaterials has reached thousands, less attention has been paid to the research on their environmental, health and safety (EHS) aspects. The results published so far on the safety of cellulose nanofibrils have shown that they are not generally toxic to humans or to the environment. However, the materials are not inert either and may cause inflammatory effects when inhaled. In addition, some indications of cytotoxicity have been found in vitro test, the cause of which still remaining unclear. Given this, it is clear that more research is needed on the EHS aspects of CNFs and CNF-based products. The material and technology development around cellulose nanofibrils has been fast, leaving the legislation and standardization activities lacking behind. There are currently no specific regulations for nanomaterials, but authorities all over the world are actively evaluating the existing legislation and its suitability for nanomaterials. Some guidance documents have already been published, for example by Organisation for Economic Co-operation and Development (OECD), European Chemicals Agency (ECHA) and the US Food and Drug Administration (FDA). In this presentation, the current status of EHS aspects on cellulose nanofibrils will be reviewed, focusing on the published literature in the field, as well as on the progress in legislation and standardization. In addition, results on the safety assessments of CNFs performed at VTT will be summarized and discussed. Recommendations on the next steps will be given based on these findings, addressing scholars, authorities as well as industry and paying special attention on the use of CNFs in paper applications.