Assessment of biological effects and harm to Japanese medaka due to carbonized carbon fibers generated by a pyrolysis carbon fiber recycling process

Abstract

Carbon-fiber-reinforced plastics (CFRPs) are used as structural materials in the aircraft and automotive industries owing to their lightweight and high strength. With increasing global demand for CRFPs, their application as an alternative to metals is expected to expand to several other fields. Consequently, carbon fiber (CF) products, such as CFRPs, have been attracting attention, and are used worldwide. However, there is little scientific evidence on the safety of CFs. In addition, problems similar to those caused by microplastics will ultimately arise if milled CFs or CF dust are released into the aquatic environment. Therefore, on the basis of existing microplastics studies, we conducted a CF ecotoxicity experiment using Japanese medaka and confirmed that the medaka were harmed by fine CF particles in an aquatic environment under static conditions, such as stagnant water, although the CFs themselves did not exhibit notable toxicity. It is possible that the rate of infection by microorganisms increased as a result.