First, the good news: despite what you might hear, recycling is not broken and it does work. According to the Environmental Protection Agency, the American recycling rate climbed from 6.4 percent in 1960 to 32.1 percent in 2018. Woohoo! Pat yourself on the back everyone.

　　But wait, there’s bad news too. As I’ve written about before, this dramatic uptick means we frequently toss items into our recycling bins that don’t belong there. Sometimes this is due to wishcycling—hoping the thing gets recycled—and oftentimes it’s just carelessness or laziness. But the presence of un-recyclable junk like chip bags, bubble mailers, and food-covered cans causes big problems at your local materials recovery facility (otherwise known as MRFs, pronounced “murphs”). MRFs are a critical step in the recycling process, where workers and machines must sort materials and remove these bad apples before they can harm equipment or spoil a batch of recyclable materials.

　　Which of these misfits creates the biggest headaches for MRF employees? I posed this question to a panel of recycling experts to get some insight. And since it’s March—and many of you will soon be filling out brackets for the NCAA basketball tournaments—I’ve created a bracket of my own. This one ranks the worst items that folks like you and me commonly toss in our recycling bins.

　　Meet Our Panel of Recycling Experts Maia Corbitt, president, Texas for Clean Water Caroline DeLoach, director of sustainability, Atlantic Packaging Janice Pare, municipal recycling expert, Massachusetts Department of Environmental Protection Heidi Sanborn, executive director, National Stewardship Action Council Justin Stockdale, Eco-Cycle Meet Our Contenders Some college basketball fans may loathe Duke or Syracuse or Villanova. This pales in comparison to the hate that recycling experts reserve for the stuff below. Our panel helped me compile a Not-So Sweet 16 list of items commonly thrown in the recycling bin that cause big problems for your MRF.

　　Plastic cutlery (which is made from fossil fuels) gets stuck in equipment and catwalk grating, sometimes flying off conveyor belts, and has no chance of being recycled, says Corbitt. Shredded or small bits of paper don’t play well with the sorting machinery at the MRFs. “They get blown all over and stick to other materials, which can render them less valuable due to contamination,” says Pare. Chip bags are made of a mix of foil, plastic, and/or paper laminated together. Since these layers cannot be easily separated, chip bags are virtually non-recyclable. I say virtually, because a company called Terracycle claims they can technically break them down and recycle them, but you either need to find a business that accepts drop- offs or pay expensive fees to do it yourself. Vape pens, which are showing up at recycling facilities at surprising rates, contain lots of bad stuff: nicotine or cannabis, which are considered hazardous waste, lithium-ion batteries, and plastic. “They are designed to be e-waste,” says Sanborn. “They should never have been allowed to be sold without a take-back program being in place!”

　　Pots and pans can tear up equipment on the sorting line at MRFs. They need to be taken to a scrap metal collection site, says Pare. Or, if they are not Teflon-coated, donate them to Goodwill! Bubble mailers confound both consumers and MRF sorting equipment, where they contaminate batches of recycling. All-plastic mailers can be recycled with plastic bags at the grocery store, but those with mixed materials (like paper exteriors) should go in the trash. Batteries, specifically lithium-ion ones, pose a serious—and growing— threat to MRFs and their workers due to fire hazard, says Stockdale. And alkalines leach toxic chemicals in landfills. Both types of batteries are recyclable, though. Just drop them off at a collection point. Staples accepts lithium-ions and you can find info about alkalines here.

　　Plastic straws fall through the sorting equipment and are just not recyclable. Refuse them every chance you get. Dirty peanut butter jars (and other food-encrusted containers) are a hazard because they can attract rats, bugs, and other nasties to the facility. But, says Stockdale, “a little peanut butter will not diminish the recyclability of a plastic or glass jar.” Styrofoam, also known as expanded polystyrene (or EPS), “is definitely not going to make its way into a valuable bale of recyclables at a MRF,” says DeLoach. “Instead, itll probably just be punctured and broken apart, leaving little Styrofoam bits (microplastics) everywhere.” Ropes and hoses are known as “tanglers” and they are a menace to MRFs. “Whoever is out there legitimately thinking it’s OK to put hoses in recycling bins, STOP IT!” says Corbitt. “Imagine throwing that rope or hose into the engine of your car! A MRF is a machine.”

　　“Solo cups are trash,” says Pare. “They’re made of polystyrene, and there is no end market for it.” Avoid buying them, but if you must, they go in the trash. “Solo cups come from fossil fuels, made disposable cool, and did a lot of damage to social norms,” says Sanborn. Old clothing and fabric messes up machinery just like hoses, says Corbitt. “Plus, textiles can be reused and/or recycled–just not in your curbside bin. Take that stuff to Goodwill!” Compostable take-out containers often look like recyclable plastics, so people think they are one and the same and try to recycle them, says DeLoach. “But these plastics cannot be recycled and when they wind up in bales with recyclable plastics, they decrease the price of the bale and make the recycling operators job harder. Compostable does not mean recyclable!” Milk and juice cartons (as well as frozen food and ice cream containers) are made from paper with a plastic waterproof coating which means they can be challenging to recycle. That said, some municipalities accept them. “Our country’s technology to repulp and recycle those paper cartons has improved a lot over the last few years,” says DeLoach. “But its far from perfect.” Check your local rules to determine whether to trash or recycle them. Plastic bags along with other “soft film” and stuff inside bags (like trash and otherwise good recyclables) make up about 40 percent of the contamination at MRFs in Massachusetts, says Pare. “They’re a huge problem because they wrap around equipment and have to be cut loose with box cutters, which is risky business for MRF workers. They have no value at the MRF.” Instead, bring them to a grocer who collects them for recycling.

　　A Tournament of Losers Prior to voting, I singled out a handful of favorites—top seeds, you might say—and expected them to make it all the way to the finals. Atop my list were bubble mailers, Styrofoam, and batteries. These things are so ubiquitous in consumer culture and also so annoying, and I assumed Id see a battle in the finals between one of the three. My prediction came true with batteries, but otherwise, my recycling competition surprised me.

　　Just like the real March Madness, my bracket produced immediate upsets. I thought everyone knew not to dump their old clothes into the recycling bin, but apparently its a huge problem. I had also viewed ropes/hoses as a lightweight, but it defeated two heavy hitters: Solo cups and Styrofoam. But ropes and hoses, my judges tell me, are quite prevalent in MRFs and when they get jammed up in the machinery, they can cause the whole process to shut down while workers perform the dangerous task of detangling them.

　　Another spoiler was vape pens, which I hadnt even considered adding to my bracket. But they surged past chip bags and plastic utensils, and nearly defeated eventual champ batteries. Why? More than 22 million vape pens were sold in the U.S. in the month of December 2022 alone! Since they contain both harmful controlled substances (toxic) and lithium-ion batteries (fire hazard) and there is no national take-back program in place, its an increasingly urgent problem for the MRFs.

　　My bracket finals featured an all-star battle between two extremely annoying foes, and in the end my panel unanimously voted for batteries as the worst offender. Why? “Right now, the biggest problem at the MRF are fires,” says Pare. “They cause financial damage and are obviously extremely dangerous for workers. The cause of those fires is more often than not, lithium-ion batteries.”

　　So, whats the takeaway of this fun exercise? Its a good idea to mentally add all of these 16 items to your no-fly list when recycling. If you ever see any of our Final Four sitting in a bin, do the right thing and yank them out.

　　Does Recycling Work? “Recycling is not broken, but it’s imperfect,” says DeLoach. “It’s definitely part of the equation, but it can’t be the entire solution.”

　　Pare wants consumers to better understand the limits of recycling without giving up on it all together. “Knowing what can and cannot be recycled is the first step toward a system that works,” she says. “The second step is buying products made from post-consumer recycled materials. Just as important is designing products to be easily recycled, using recycled feedstock. Recycling is happening despite what people have read, but theres always room for improvement.”

　　The government also has an important role to play.“We need better public policy that provides the financial incentives (and disincentives) that have worked in other arenas, like deposit systems or disposal fees, to build a better system,” says Corbitt.

　　So please, let’s not give up on recycling! Instead, let’s do it better while also remembering that recycling comes after refuse, reduce, and reuse in the waste hierarchy.

　　Doing right by the planet can make you happier, healthier, and—yes—wealthier. Outside’s head of sustainability, Kristin Hostetter, explores small lifestyle tweaks that can make a big impact. Write to her at [email protected].