2,5-Dimethylfuran (DMF) is being considered as a potential green transportation biofuel, but there is limited information about its toxicity and safety. We examined DMF toxicity in the bone marrow using a murine in vitro erythropoietic micronucleus assay and found that exposure to DMF (0.1 mM, 1 hr) induced an increase in micronuclei frequency compared with controls. These data suggest that DMF may be genotoxic to hematopoietic cells and that more thorough toxicological studies on DMF should be conducted to ensure public and occupational safety before it is considered a viable biofuel and produced in mass quantities. As well as specific data on DMF, our study further validates an in vitro cell culture system that captures the essential features of the in vivo mammalian micronucleus genotoxicity assay, enabling increased throughput and controlled studies on hematopoietic DNA damage response, while reducing animal sacrifice. In vitro assays, such as the in vitro micronucleus assay, will be essential as international chemical policy is increasingly utilizing green chemistry principles that require more toxicological testing. Environ. Mol. Mutagen. 2012. © 2012 Wiley Periodicals, Inc.