The Verdict Is In: Keep the Bottle Caps On

One of the unwritten rules of many curbside recycling programs may be on its way out.

For years, consumers have been told to remove container caps prior to recycling. But a statement released this week by the Association of Postconsumer Plastic Recyclers (APR) claims that plastic recyclers support including the bottle caps.

“We want to assure recycling coordinators, MRF operators and other collectors of recyclables that plastics recyclers will process these bottles and recover the caps for recycling purposes,” said APR Chairman Scott Saunders. He added that APR members report growing demand for the caps themselves.

To sum up that statement, you can leave the caps ON your plastic bottles when recycling.

One primary issue has been that most plastic bottles are manufactured with polyethylene terephthalate (PET, or plastic #1 based on resin codes) or high density polyethylene (HDPE, plastic #2), while the cap is typically made of polypropylene (PP, plastic #5).

In plastics recycling, resins must be separated before they can be processed because they have different melting points, so caps and rings are removed.

Other factors often cited for not including bottle caps include safety issues because if the caps are left on, they can shoot off at high speeds when bottles are crushed for transport. If caps are left on and bottles aren’t crushed, it will mean fewer bottles can be transported since space will be taken up by “air weight.”

To get around this, the APR recommends that consumers crush bottles prior to putting the cap back on. The organization also says that bottles should be free of liquid, but rinsing is not necessary for recycling.

Keep in mind that even though plastic recyclers support including caps and are able to process the material, you should always follow the instructions of your local recycling program*. This also does not affect glass bottle recycling, as many recyclers request that those metal lids are removed prior to recycling.

*Republic Services: Recycling plastic and bottles

This APR statement is more of a clarification on the recyclability of caps, and APR says the ideal situation would be for manufacturers to use the same resin for bottles and caps.

Earth911.com: How to recycle plastic caps & lids

Watch the video below of the separation process for plastic bottles, caps and labels