Diligent recyclers know that food-contaminated paper is an item non grata in your curbside bin. There are a few reasons for this. For one thing, it means increased costs at the sorting facility. Baled paper can sit for weeks before it gets pulped—plenty of time for any food particles to spoil and rot, making life highly unpleasant for the mill workers. Finally, greases and oils can be tough to remove completely. Whether or not that's going to be a problem depends on what the mill is making—a bit of grease won't be a big deal if the end product is brown grocery bags or tissue paper, but it could easily ruin a batch of white office paper.
Pizza boxes may not be the worst offenders in this regard, because they're big enough to be identified and removed at the sorting facility. Plus, the cheesy residue is likely to stay contained within the box. Recyclers have more trouble with things like salad dressing—oily foodstuffs that might drip onto other items in a bale.
What should I do with old books—can they be recycled?
Yes, but probably not through your curbside program. Some communities, like New York City, do accept paperbacks and phone books, but they won't take hardcovers, which contain problematic binding glues and coatings on the covers. If your library can't be donated or swapped, search the database at Earth911.com for a book recycler in your area. Failing that, you can slice out the pages using scissors or an X-Acto blade and put them in with your regular paper recycling.
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