South Africa was the third largest exporter of asbestos in the world for more than a century. As a consequence of particularly exploitative social conditions, former workers and residents of mining regions suffered--and continue to suffer--from a serious yet still largely undocumented burden of asbestos-related disease. This epidemic has been invisible both internationally and inside South Africa. We examined the work environment, labor policies, and occupational-health framework of the asbestos industry in South Africa during the 20th century. In a changing local context where the majority of workers were increasingly disenfranchised, unorganized, excluded from skilled work, and predominantly rural, mining operations of the asbestos industry not only exposed workers to high levels of asbestos but also contaminated the environment extensively.