Since October 2019, some 2000 members of the United Steelworkers union have been engaged in ongoing strikes over stagnant wages and alleged unfair labour practices at five copper facilities in Arizona and Texas owned by ASARCO - a subsidiary of international mining firm Grupo México. Workers voted to strike after receiving ASARCO's latest contract offer, which includes no wage increase for nearly two-thirds of workers, no pension increases for workers hired before July 2011 and more than doubles the out-of-pocket contribution individual workers already pay for healthcare. Workers have not had a wage increase for 10 years. According to the union, ASARCO has failed to bargain in good faith and has threatened to hire, and has hired, permanent replacements to replace employees engaged in the strike.

In May 2020, Business & Human Rights Resource Centre invited ASARCO and Grupo México to respond to allegations made by the striking workers of unfair labour practices – including failure to bargain in good faith, stagnant wages and cuts to benefits. Both companies did not respond.