Dear Recyclebank: What can I do with the caps on plastic bottles? I’ve heard that they need to be removed before the bottle is recycled, but I hate throwing them away. –Bethie
Dear Bethie: Whether or not you can recycle bottle caps and whether they belong on or off plastic bottles depends on where you live. In Fort Worth, TX, caps must be taken off the bottle but can then be recycled. Meanwhile, Philadelphia asks its residents to leave caps on plastic bottles, but remove them from glass bottles.
In an interview with NPR’s Mike Pesca, Sierra Magazine’s Lifestyle Editor, Josie Garthwaite, explained that municipalities often limit the materials they accept for recycling because of the cost associated with sorting the various materials; perhaps the biggest reason bottle cap disposal procedures vary so much from place to place is that bottle caps are hard for MRFs to sort efficiently. Bottle caps are usually made from a different type of plastic than the bottles they seal shut. While most plastic water bottles are made of polyethylene terephthalate (#1 PET plastic), most bottle caps are made from polypropylene (#5 PP plastic). PET has a melting point of almost 500° Fahrenheit, whereas PP will melt at only 320° Fahrenheit; this difference in melting points means that the two materials must be separated from one another prior to being melted down for reuse. But removing the caps from their bottles before you put them in the recycling bin isn’t a surefire solve: Because they’re so small, they’re likely to fall off conveyor belts during the sorting process and end up in the garbage, possibly representing a loss to the recycling company as a result.
If your curbside recycling program accepts both #1 and #5 plastics, you may not have to throw your bottle caps out — you may even be able to leave them on the bottle. Still, your best choice is to just call your hauler to find out what they specifically want, as procedures vary from town to town, and even by neighborhood in some cases.
If your hauler says they won’t accept plastic bottle caps in any form, look for local recycling centers to accept your plastic bottle caps. If you don’t have any recycling centers nearby, repurpose them! Turn them into cute magnets for your fridge with just a few supplies from your local hardware store, or collect them and once you’ve amassed a large quantity make them into a mosaic.