Slice of Sustainability: What to do with Pizza Boxes?

If you’re like me, you may eat pizza on a weekly (if not daily) basis. I think it’s one of the greatest foods in the world, and it often requires the least amount of meal prep and clean-up.

So what do you do with that giant cardboard pizza box?

Many people assume that pizza boxes are recyclable. In fact, most boxes are recyclable, since they’re made from corrugated cardboard.

What makes pizza boxes NON-recyclable is the hot, tasty treat that comes inside them – specifically, the grease and cheese from the pizza that soils the cardboard.

So there you have it – pizza boxes that are tarnished with food, or any paper product that is stained with grease or food, are not recyclable – unless you remove the tainted portions.

Why is this, you ask?

When paper products like cardboard are recycled, they are mixed with water and turned into a “slurry.” Grease from pizza boxes causes oil to form at the top of the slurry, and paper fibers cannot separate from oils during the pulping process. Essentially, this contaminant can ruin an entire batch of recycling. (Gasp!)

Food is one of the worst contaminants in the paper recycling process. The easiest remedy for this problem is to cut or tear out the soiled portions of your pizza boxes and trash them. For example, you can tear the top of the box off, recycle that and throw away the bottom part containing the grease. If the entire box is grease-free, the whole box can be recycled with a guilt-free conscience.

Think of food products that often stick to their container, such as yogurt, hummus tubs and cream cheese containers. These containers are typically made from plastic #5 – or polypropylene. However, be sure to rinse these food products off the plastics as well. These containers are melted down and mixed together to be shipped overseas. While tubs don’t have to be scrubbed clean, it’s good to err on the side of rinsing or cleaning out larger amounts of food, particularly in single-stream recycling, so that a high-quality material can be used in a new product.

An alternative to recycling cardboard is to compost it! The amount of grease on the pizza box is not going to cause any problems in your compost pile. At the most, it could attract unfriendly pests who will smell the pizza-ey goodness and want to investigate. If you’re concerned about this, just bury the greasy part of the box about a foot deep in your compost pile and you shouldn’t have a problem. Tear or cut the box into smaller pieces first so they’ll break down faster.

Sources: Earth911, OrganicGardening.About