Why can’t I recycle pizza boxes?

Why am I not supposed to recycle paper products with food still on them, like food-stained pizza boxes? Isn’t it still better than just throwing them away?

— Concerned (but hungry) in Vermont

Very glad you asked.

Turns out the self-proclaimed environmental-know-it-all has been contaminating the recycling stream.

My city — like many by now — has adopted a “single stream” collection system, meaning that recyclables need no longer be sorted into separate bins (glass, paper, plastic). It all gets dumped together in the collection truck and sorted out on site. So, I figured, better to err on the side of green and put everything in the bin rather than throw away something potentially recyclable. It’ll all get sorted anyway, right? Oops.

Food, it turns out, is one of the worst contaminants in the paper recycling process. Paper to be recycled likely sits around for a while, and remnants will begin to biodegrade the paper. OK if it’s in your compost, but not for the recycling market. Whole batches of otherwise recyclable paper end up in the landfill because of spoilage due to food. Other relatively small intruders — wet paper, adhesives, wax or plastic coated paper — can also land big batches of paper in the landfill. Phoenix spends nearly $1 million a year dealing with these offending materials (no, no, not those offending materials. Those can be recycled). Adhesives alone cost the paper recycling industry an estimated $700 million per year. Damn.

So better to leave the food covered paper out of the bin; you’ll be allowing more to be recycled in the long run.

Keep your recycling questions coming. I’m curious to know how else I’ve been amiss!

Keep it green,


Recycling help

Not sure what can be recycled or where? Go to and enter your ZIP code along with whatever you want to recycle. You’ll find all the what and where of recycling in your area. Very handy for those hazardous or hard-to-recycle items. But wait, there’s more!

nYou can always tear out the oily, cheesy parts of the pizza box and recycle the rest of the box. Don’t stop there: Even the oily, cheesy part of your pizza box need not fill the landfill.

nCompost it. If you compost at home, throw it in the pile (smaller, torn pieces, will decompose faster). If not, add it into the “yard trimmings” bin, and it will be composted at the municipal level.

nThat goes for paper towels and napkins, too. And toilet paper rolls. And tissue. And food scraps.

Good to know

nPaper can be recycled up to seven times, and is easier and cheaper to make pulp out of than wood.

nBecause they will separate easily enough in processing, don’t sweat over things like paper clips, small plastic envelope windows, staples and metal envelope latches.

nPeel and stick adhesives can ruin an entire roll of recycled paper. Get those “complimentary” address labels and other stickers out before you toss the junk mail. Same goes for sticky-notes.

nDon’t shred paper unless you really need to. Most recyclers won’t accept shredded paper.