Many major U.S. companies — including some of the country’s biggest consumer brands — say they are taking steps to eliminate child labor in their domestic supply chains amid revelations that children are working throughout American manufacturing and food production...

Now, McDonald’s says it is requiring private inspectors to review overnight shifts at slaughterhouses that provide some of its meat, where children as young as 13 were cleaning heavy machinery. Suppliers for Ford Motor Company must now scrutinize the faces of employees when they arrive for work. Costco is commissioning more audits with Spanish-speaking inspectors...

Along with McDonald’s and Costco, Starbucks, Whole Foods and PepsiCo are revising the kinds of audits they require at their suppliers. The changes include enhancing reviews of night shifts and shifts run by outside contractors, such as cleaning companies, and moving away from announcing audits in advance...

“We have been actively evolving our focus on the risk of migrant child labor domestically,” Whole Foods said in a statement.

Spanish-speaking auditors said recruiters were courting them as firms raced to staff up...

Auditors expect child labor to be a major focus of corporations this year. In January, Amazon convened companies including Target, Disney and PepsiCo to discuss ways to eliminate underage workers in American supply chains. Another summit, this one sponsored by Walmart and focusing on improving social audits, is planned for March.

The nonprofit groups Verité and AIM-Progress, which promote responsible labor practices, are retraining 600 American suppliers and staffing agencies. The initiative is funded by 12 corporations, including some companies that The Times found had benefited from migrant child labor: McDonald’s; General Mills; the snack food giant Mondelez, which owns Oreo and dozens of other products; Cheez-It’s owner, Kellanova; and Unilever, the company behind Ben & Jerry’s. The new guidance directs suppliers to ensure that any children found working are given social services, and not simply fired.

“They should also be looking at what they’re paying people,” said Verité’s chief executive, Shawn MacDonald, “and why they’re having trouble finding people beyond children who are willing to take this work.”