Xenobiotic chemicals (for example, PCBs, BPA and methylmercury) play a central role in the new field of ‘environmental epigenetics’, which identifies factors that regulate the expression of genes, thereby suggesting the fundamental plasticity of biology. This article examines the role of race in the emerging ‘epigenetic biopolitics’ of environmental chemicals. Analysis of the paradigmatic case of methylmercury contamination in fish reveals a new racial formation in which race is important precisely because biology is plastic. Because methylmercury affects fetal neurodevelopment, US regulatory agencies aim to control fetal exposures by issuing fish consumption advisories to women of childbearing age. Owing to racial disparities in fish consumption, not only do the advisories have greater impact on women of color, but they change the problem from contamination itself to the abnormal diets of these women. Then, to the extent that these women fail to make the right choice, this leads to bodily differences between people of purportedly different races. In this epigenetic biopolitics, in which the aim is to affect cellular processes of the developing fetus, it is the reproductive woman who is racialized and who, through her actions, produces embodied race.