A greasy pizza box can be hard to recycle since the grease stains can contaminate the load of recyclable cardboard. So here's one thing you can ask for the next time you order pizza: Ask them to place a sheet of aluminum foil on the bottom of the box, then place the pizza on top. This helps keep the grease from seeping into the cardboard, plus it keeps the pizza hotter. And don't forget: If the aluminum foil is clean enough, just crumple it up and toss it into the recycling bin. It's recyclable!