Risk assessment of polymer composites containing cellulose nanofibrils (CNF)

Cellulose nanofibrils (CNFs) have shown potential as strengthening agents in polymer composites. In addition, as bio-based nanomaterials originating from abundant raw material source, they offer sustainable alternative for manufacturing of light-weight composites with reduced carbon footprint. In general, CNFs have been found to pose no immediate threat to human health or to the environment. However, exposure to CNFs during production, use or end-of-life may lead, for example, to inflammatory effects of employees or unwanted adverse effects in the environment. In this presentation, risk assessment performed to polymer nanocomposites containing CNF will be reported. Exposure assessment will take into account occupational and consumer exposure as well as exposure to environment. Occupational exposure is considered by reviewing the manufacturing step-by step and is focused on the closed system approach and possible machine-tooling methods applied. Potential migration of CNF and exposure through wear and tear is taken into account when considering the consumer exposure. Exposure to environment is considered both during production by identifying the steps in which the exposure to environment is possible and also during end-of-life, i.e. waste management. In addition, hazard assessment is performed taking into account the properties of CNFs in question. In the final risk assessment, the results from exposure and hazard assessment will be combined. Based on the assessment, recommendations can be given on risk management procedures based on the closed system approach for the manufacturing, use and disposal of CNF-polymer composites.