It’s a problem that highlights some of the drawbacks of our recycling system.

Tim Nelson
Updated: March 27, 2019

If you’ve ever desperately wanted to impress people at some point in your life, you’ve probably crushed a soda (or beer) can with your hand. Or stomped on it. Or slammed it against your forehead because that’s what true alphas do. It probably looked rad. As it turns out, though, crushed cans can be awful for recycling systems.

In essence, crushing cans makes it harder to sort the compressed aluminum and ensure it’s dealt with properly. While plastic bottles can do just fine when they’re crushed and condensed a bit before reaching a sorting facility, aluminum cans are much easier to misclassify in those situations. It’s often the case that flattened aluminum cans end up being sorted as paper and gumming up the works. In addition to improper sorting, the compact size of a crushed aluminum can can quite literally slip through the cracks at sorting facilities, making it difficult to even account for them properly.

It’s worth noting that this issue tends to only plague single stream recycling systems, which encourage residents to co-mingle their recyclables before collection. Multi-stream recycling, which forces consumers to make the distinction between paper and plastics/metals on their own, isn’t faced with the crushed aluminum can issue given that recycling facilities aren’t tasked with figuring out what it is on their own.

The problem is that roughly 80% of Americans used single-stream systems as of 2014. It’s easy to understand why: the convenience factor of “drag it to the curb and let someone else sort it out” encourages participation. Trucks that pick up recycling also don’t have to use separate compartments, meaning they can make more trips to processing centers faster.

But as more and more cities are realizing, the crushed aluminum can issue is just one of the many increasingly apparent costs of easy recycling. We tend to employ wishful thinking when it comes to recycling, putting waste items in our recycling bins that end up “contaminating” the supply. That’s a huge problem for the people tasked with doing the actual recycling.

“When we collect the material, it has as much as 25 percent contamination, but by the time we sell it it needs to have less than one percent,” Waste Management senior director of sustainability and policy Susan Robinson told Popular Science. “It increases our costs, it causes safety problems, and it increases the environmental burden.”

Crushed aluminum certainly contributes to that contamination. Susan Collins of the nonprofit Container Recycling Institute told 538 that as many as one out of three cans end up getting sorted and shipped out wrong because they’re misidentified.

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Even worse, sometimes the way trucks in single-stream systems treat their materials means that even the cans that are handled with care can end up in the wrong place. “The trucks are constantly compacting, smashing the materials together,” Collins told 538. “The glass breaks and shards get into the plastic and the paper. Aluminum cans and plastic bottles that get smashed have the same profile as the paper does.”

So if you want to be a better recycler, make sure to handle your aluminum cans with care and be thoughtful about what you actually toss in the recycling bin. Then, accept that even those efforts might not be enough. If you really want to make a difference, petition for multi-stream recycling in your municipality and hope for the best.