Children are working dangerous jobs at JBS meat processing plants in Minnesota and Nebraska, hired illegally for overnight shifts and tasks that left a 13-year-old with caustic chemical burns, federal officials say.An investigation launched in August found that PSSI hired at least 31 children — ranging in age from 13 to 17 — to fulfill the company's sanitation contracts at JBS plants in Grand Island, Nebraska, and Worthington, Minnesota, and at Turkey Valley Farms in Marshall, Minnesota, Labor Department officials said.The jobs performed by kids allegedly included cleaning dangerous powered equipment with corrosive cleaners during overnight shifts, and cleaning floors where animals are slaughtered.If true, they would violate the company's ethical policies, according to Michael Koenig, chief ethics and compliance officer at JBS USA, a unit of Brazilian meat giant JBS.The biggest producer of beef in the U.S., JBS USA is the nation's second-biggest producer of pork and poultry, employing more than 66,000 people at 55 facilities across the U.S."We are immediately launching an independent, third-party audit at all of our facilities to thoroughly evaluate this situation."