This article applies Gieryn’s two concepts of boundary-work, ‘expansion’ and ‘exclusion’, to observing ‘Environmental Justice’ (EJ) research. The application of boundary-work in the field of EJ science shows that similar phenomena noted in Gieryn’s case studies can also be found in EJ research. EJ scientists continue to shape and reshape the meaning of EJ. Meanwhile, activists also use rhetoric boundaries to discredit the legitimacy of EJ’s opponents. We suggest that the EJ movement is still dependent on scientists to provide a scientific way to foster equal distribution of environmental risks. However, to achieve a just distribution, science along is not enough. Public participation in the field of both EJ science and the political movement is necessary.