The Democratic Republic of the Congo produces nearly three-quarters of the world’s cobalt, an essential component in rechargeable batteries powering laptops, smartphones and electric vehicles. But those who dig up the valuable mineral often work in horrific and dangerous conditions, says Siddharth Kara, an international expert on modern-day slavery and author of Cobalt Red: How the Blood of the Congo Powers Our Lives. In an in-depth interview, he says the major technology companies that rely on this cobalt from DRC to make their products are turning a blind eye to the human toll and falsely claiming their supply chains are free from abuse, including widespread child labor. “The public health catastrophe on top of the human rights violence on top of the environmental destruction is unlike anything we’ve ever seen in the modern context,” says Kara. “The fact that it is linked to companies worth trillions and that our lives depend on this enormous violence has to be dealt with.”