Occupational Risk Assessment During Carbon Fibre Sizing Using Engineered Nanomaterials

Carbon fibre-reinforced polymers (CFRPs) are a lightweight alternative solution for various applications due to their mechanical and structural properties. However, debonding at the fibre–matrix interface is an important failure mechanism in composite materials. Proposed solutions include using nano-scale reinforcements to strengthen and toughen structural composites. This study covers a comprehensive approach for evaluating occupational hazards during the sizing of 6k carbon fibres using multi-walled functionalized carbon nanotubes (MWCNTs) and few-layer graphene (FLG) at a pilot scale. Material hazard and exposure banding showed elevated risks of exposure to nanomaterials during the sizing process, while a ‘what-if’ process hazard analysis allowed for the evaluation of hazard control options against the hypothetical process failure scenarios of human error and utilities malfunctioning. On-site measurements of airborne particles highlighted that using MWCNTs or FLG as a sizing agent had negligible effects on the overall exposure potential, and higher micro-size particle concentrations were observed at the beginning of the process, while particle size distribution showcased high concentrations of particles below 50 nm. This analysis provides a thorough investigation of the risks and potential exposure to airborne hazardous substances during CF sizing while providing insights for the effective implementation of a safe-by-design strategy for designing targeted hazard control systems.