Cans used for food require tin-coated, ultrathin sheet steel made from molten iron. The Trump administration’s new 50% duty on imported steel could increase store prices for items in steel cans by 9% to 15%, according to the Consumer Brands Association, a trade group whose members include Campbell’s Hormel Foods and Del Monte Foods. At that rate, the price of a can of vegetables costing $2 could increase by 18 cents to 30 cents.