Living in colonies on the Midway Atoll in the Pacific Ocean, adult Laysan Albatross skim the water to catch fish which they regurgitate to feed their young.  Floating on the surface, small items like bottle caps are scooped up and fed to fledgling albatross – who cannot live with plastic trapped in their stomachs.  An estimated five tons of plastic are fed to young albatross annually. The Midway Atoll is located nearly 1,500 miles northwest of Hawaii; 3,400 miles from California; and 4,700 miles from Asia.  These albatross are feasting on bottle caps originating thousands of miles away.

Often I pause over the recycling bin with a bottle in one hand and a cap in the other: Are the caps recycled on or off the bottles?  We are making better choices with limiting plastics we consume and with recycling those that make their way into our home, but how can I keep caps from ending up on the Midway Atoll?

According to Hiltz Hauling & Recycling, the curbside hauler in Marblehead, MA, bottle caps can be recycled on or off the bottles.  Hiltz delivers recycled items to Casella Recycling in Boston and plastics are sorted by type using computerized optical sorters: cameras, lights, and air jets.

When the plastics are transferred to mills, where they will become new products, they are further sorted.  In a relatively new process, plastic is finely shredded, cleaned, and placed in float tanks where the materials are separated based on whether they sink or float.  Specifically, the cap material, polypropylene (PP), floats and  bottle material, polyethylene terephthalate (PET), sinks.

With this advanced sorting float/sink process, the Association of Postconsumer Plastic Recyclers (APR) has set guidelines for recycling caps: twist them back onto the bottles.  However, the APR points out that this process is relatively new and that it may take a while for all communities to adapt to the “cap-on” guideline.

From earth’s perspective, if caps can’t be screwed onto bottles, then they shouldn't go into our recycling bins but rather in the trash.  Since the caps are so small, they are apt to become litter during transport.  And possibly breakfast for an albatross.

Source websites:

Earth 911, May 1, 2015

Smithsonian, National Museum of Natural History, May 1, 2015

Marblehead Recycling Guidelines, May 1, 2015

Hiltz Single Stream Recycling Guide, May 1, 2015

The Association of Post Consumer Plastic Recyclers, May 1, 2015