Pizza Boxes Put in Garbage Cart Used pizza boxes cannot be recycled because they are soiled by food residue and grease. Did You Know? The Cost of Recycling the Pizza Box Greasy pizza boxes contaminate clean recycling and are expensive for the recycling industry: it’s estimated that contamination costs recyclers $700 million per year, because of damaged machinery, the cost of disposing of non-recyclable materials and wasted time. What Came Before Pizza Boxes? Around two-thirds of all pizzas are delivered in pizza boxes. Pizzas first came in wax-lined paper bags just like pies. Between World War I and World War II, they started coming in boxes made from corrugated cardboard.