Paper products and containers made of glass and aluminum are usually accepted. Plastic is more confusing, but if you stick to bottles, tubs, jars, and jugs, it’s hard to go wrong, says Bailey. Containers need to be empty. “With things like peanut butter, you don't really need to scrub it all out, it doesn't need to be pristine,” says Bailey. “[But] we appreciate if you can give it quick rinse.” Food residue attracts pests like rats, racoons, and wasps to facilities. In paper products, food can actually ruin the material, making it unrecyclable. “If you have a really greasy, cheesy pizza box, for example, we ask people to compost it instead of recycling it,” says Bailey.