In partnership with the National Geographic Society. This story is part of Planet or Plastic?—our multiyear effort to raise awareness about the global plastic waste crisis. Learn what you can do to reduce your own single-use plastics, and take your pledge.

Much like the plastic straw, six-pack rings are often seen as enemies of the ocean. Though straws and six-pack rings account for only a tiny fraction of all the plastic trash in the ocean, images of hapless marine animals like sea turtles with plastic straws jammed into their noses or plastic six-pack rings encircling their bodies have sparked public backlash against the common items.

Now, some beer companies are trying to create new, innovative ways to hold their cans together without trapping marine animals in any resulting refuse.

Unlike plastic straws, however, viable alternatives aren't always readily available. When the straw was first commercially produced, it was made of paper, making the move away from plastic simply a return to the straws of yore.

The History of Six Packs

Plastic rings have been available for four decades, and they are now more heavily regulated than they were when first produced.

In 1987, the Associated Press reported that as many as one million seabirds and 100,000 marine mammals were killed every year by six-pack rings. That figure is widely cited and still used today, but can't easily be traced to its origin. In 1984, the New York Times reported from a conference of the Washington-based Entanglement Network that 100,000 marine mammals die after encountering plastic every year.

In one beach clean-up on the Oregon coast organized in 1988, volunteers picked up 1,500 six-pack rings in the course of a few hours.

Manufacturing company Illinois Tool Works claims “the beverage packaging industry was transformed” when an operating unit within that company called HiCone invented six-pack rings in the 1960s. Today, that same unit manufacturers a variety of plastic six-pack rings on machines it says can package 2,400 cans per minute.

Since 1994, the EPA has mandated that all ring carriers sold in the U.S. must be degradable. Many manufacturers meet this standard by making their rings photodegradable, which means they break down in light.

HiCone uses the technique and says at most it takes three to four months for the rings to break down in cloudy, winter-like conditions. While this regulation makes it less likely animals will be entangled by the rings, it still leaves the possibility that they might consume the smaller byproducts formed as the plastic breaks down. EPA regulations say the resulting plastic fragments can range from particles too small to see with the naked eye to pieces several centimeters across.

Almost 700 species are now known to have been harmed by ocean plastic, and every year, around 18 billion pounds of plastic flows into the ocean. Forty percent of that is single-use plastic—plastic that is used once and then thrown away. Marine animals from birds to mammals are impacted, not just from the entanglement risk before the rings degrade, but from ingesting micro-sized plastic particles that can eventually cause them to starve (by plugging up their digestive systems).

Scientists have described microplastics as a kind of “plastic soup,” and studies say that anywhere from 15 to 50 trillion pieces of microplastic are in the ocean.

Producing plastic rings also requires using petroleum—around eight percent of global oil production is to make plastic.

Alternatives to Plastic Rings

To cut down on microplastics and carbon emissions, some companies are turning away from plastic rings altogether.

In 2016, the beer company Salt Water Brewery announced all their six-packs of Screamin' Reels IPA would be packaged with a compostable holder termed E6PR (Eco Six Pack Ring). The container is designed to be completely compostable when thrown away and edible if it enters marine animal habitats. It's made with some of the byproducts produced from brewing beer, like spent wheat and barley.

A Brief History of How Plastic Has Changed Our World

“I can't speak to the nutrition of barley to sea turtles, but it does seem a lot more benign if ingested than traditional six-pack plastics,” Nick Mallos, director of the Ocean Conservancy's Trash Free Seas program, told National Geographic in 2016.

In June, Danish beer company Carlsberg Breweries announced they would be using a newly engineered type of glue to hold their six packs together.

It took three years and 4,000 iterations to make an adhesive that was strong enough to keep the cans together but not so strong that consumers couldn't easily pick one off, says Carlsberg sustainability director Simon Boas Hoffmeyer.

Hoffmeyer declined to disclose specifics about what made their glue unique or how much it cost, but noted it's not unlike other adhesives already on the market.

“It's the same type of glues or adhesives found in other products, but the exact composition is different. The way we use the glue is different,” he added. “We have done tests that show there is no impact on the recyclability. We recommend to leave the glue on the cans so we ensure it doesn't end up in the wrong places.”

Each six pack will still contain a “handle” made of a thin strip of plastic affixed to the two middle beer cans. Still, the beer company says it will help them avoid using 1,322 tons of plastic every year.

While manufacturers hope it will make a dent in the amount of plastic pollution that enters the ocean every year, plastic rings are no where near the largest portion of plastic refuse found at sea. The Ocean Conservancy stages beach cleanups every year where volunteers collect trash. In 2017, cigarette butts were the biggest source of plastic pollution—1,863,838 were collected.