Measures of corporate environmental justice performance can be a valuable tool in efforts to promote corporate social responsibility and to document systematic patterns of environmental injustice. This paper develops such a measure based on the extent to which toxic air emissions from industrial facilities disproportionately impact racial and ethnic minorities and low-income people. Applying the measure to 100 corporate air polluters in the United States, we find wide variation in the extent of disproportional exposures. In 54 cases, minorities, who represent 31.8 percent of the U.S. population, bear excess burden; in 15 of these cases, the minority share exceeds half of the human health impacts from the firm's industrial air polution. In 66 cases, poor people, who represent 12.8 percent of the U.S. population, bear excess burden.