A new law giving border authorities greater powers to block or seize goods made using forced labor in China comes into effect Tuesday. The Uyghur Forced Labor Prevention Act (UFLPA) means the fashion industry will have to end its reliance on cotton from the Xinjiang region in northwest China, as the new law assumes any product made wholly or even partially in Xinjiang is linked to the area’s forced labor camps. Since 2017, as many as two million Uyghurs and other Muslim minorities have been held in the camps and subjected to brutal treatment—the U.S. State Department has called Beijing’s oppression of the groups “genocide.” Around a fifth of the world’s cotton originates in China, with an estimated 84 percent of that coming from Xinjiang.