Cleaning my recyclable containers just feels right, but does it matter?

I’m a peanut butter fiend. I add it to my smoothies and my granola, top it with some dark chocolate chips for a “healthy” dessert — let me lie to myself, please — and often eat it straight from the jar. But every time I finish a last spoonful, I face a dilemma: how do I recycle the container?

As someone who tries to do what I can for the environment, I resort to the extreme. I run my kitchen sink until the water is burning hot (more on that later), let the container fill up and leave it overnight. The next morning, I scrub it clean and toss it in the recycling bin. It certainly takes some elbow grease to remove all of the leftover peanut butter.

Most people I know have similar habits, preparing their recyclables to the extreme to be as eco-friendly as possible. But a few others in my life go in the other direction, having read claims on social media that recyclables just get sent to landfill. And so they have come to think the extra effort of cleaning them is pointless.

So, which is it — should I be scrubbing my Skippy’s jar, or not? 

Garbage puts a massive burden on the environment. Plastic waste, for example, is dumped into waterways by the tens of millions of tons every year, which has devastating effects on aquatic animals like whales and seabirds. Solid waste in the 2,639 landfills across the United States produces methane, carbon dioxide and water vapor, all of which contribute to climate change. And we aren’t slowing our consumption any time soon, with American plastic waste expected to about double by 2060.

As a New Yorker, I produce more than four pounds of trash a day, so it’s crucial that I — and also you, dear reader — understand how to minimize the associated negative impact by recycling properly.

It turns out that neither group of people in my life is right. There’s no need to make your recyclables spotless, but if they’re mostly empty, they will often stay out of landfill and be put back into the materials economy.

Most objects “don’t have to be sterilized, they don’t have to be washed, they just need to be empty,” explained Mitch Hedlund, who leads the nonprofit Recycle Across America. That’s especially true in New York City, according to Sophia Huda, a sustainability lecturer at Columbia University and Fordham University. The city’s Sunset Park Material Recovery Facility is considered one of the most advanced recycling facilities in North America, she said. Its advanced technology and massive capacity mean that there is even less pressure on local consumers to make their recyclables spick and span and sort them correctly.

And while some stuff you put in your recycling bin goes to landfill because of contamination, most doesn’t. In New York City, 28% of metal, glass and plastic recycling and 15% of paper recycling get sent to landfills because of contamination. That means that most of what we opt to recycle actually gets recycled. Nationally, about 25% of what gets put into recycling bins ends up at landfills, according to the National Waste & Recycling Association.

Recycling metal and paper is relatively painless, explained John Atkinson, an environmental engineer at the University at Buffalo. Recovery facilities use magnets and other tools to easily separate steel and aluminum, for example, which are high-value materials and are very likely to be turned into another consumer product. Paper and cardboard are similarly straightforward, he said.

The materials that cause the most trouble in the recycling process are glass and plastic, so they’re generally responsible for most of what gets sent to landfill. Glass often breaks into small pieces during transportation and becomes abrasive and sharp, which makes it hard to isolate from a mountain of commingled material. 

Even when glass does get recycled, the resulting color makes it difficult to sell after processing. “You have a clear Corona bottle, a green Heineken bottle and a brown Bud Light bottle. You mix all that together and you’ve got sharp, heavy, and abrasive gray glass,” for which glass buyers have limited use, Atkinson said. The color can be altered, but it’s usually not worth the cost to do so.

“Plastic is its own beast,” he continued. Think of the different numbers you see on the bottom of takeout containers and packaging — plastic is not a single material, but many materials grouped together, which makes it hard to sort cost-effectively. Most plastics are cheap to produce from scratch, which further lessens the market’s incentive to recycle them. Yet again, sorting and economic factors lead to recyclable materials ending up in landfill.

Everyone I talked to — academics and advocates alike — agreed that prepping recyclables does more good than harm. But it has some downsides, like using energy to heat the water that cleans the peanut butter jar, for example. If you live somewhere that has a drought, you might want to think twice, said Josh Rottman, a psychologist at Franklin & Marshall College who studies the ethics of recycling.

That said, the upsides to cleaning are overwhelming. There are obvious benefits, like keeping recyclables from being contaminated, which in turn prevents some of them from being sent to landfill and having harmful effects on the environment and climate. Allowing plastics to sit in dumps is also thought to affect human health, said Janet Yang, who studies environmental communication at the University at Buffalo. “It’s not just the environment that we’re contaminating,” she said. “It’s going to be in all of our bodies.”

Caring for recyclables also encourages people to get excited about environmentally friendly acts. Atkinson compared it to the way people are enthusiastic about reusable shopping bags. He noted the excitement people have when they tell their cashiers that they brought a bag from home, and the joy they get from other shoppers overhearing the conversation. “It’s that enthusiasm and attitude, and that willingness to talk about it” that spawns more environmental action, he said.

During conversations with these experts, I asked how the recycling system could be made more effective. They all agreed that education about proper recycling — encouraging people to learn more about how local recycling systems work —  is the biggest challenge. Many suggested that everyone should research their local municipality’s rules and regulations. (You can find a handy-dandy search tool for individual materials here.)  “So much of this is just not obvious or intuitive,” Rottman said. 

“If you pull a random person off the street and you say, ‘What happens to your trash or recycling?’,” Atkinson said, they will tell you that the process is easy and simple, “as though it’s a magic trick.” For the average person, our waste is mostly out of sight and out of mind, so we don’t need to know much about how it’s produced or what happens to it after we say goodbye. A survey by Yang and her collaborators suggests that assumptions about recycling, not facts, drive people’s choices. Some may not recycle containers with hints of food still attached, for example, because they assume that any debris renders the container non-recyclable. 

More robust education would allow people to better understand recycling labels. Even when a piece of plastic has a number on it, for example, “the public doesn’t know what the various numbers in the chasing arrows are for. They just see the recycling symbol and think all plastic containers are recyclable, even if they aren’t. It’s misleading,” Hedlund said. Just seeing a number encourages people to recycle an object, even if that type of plastic isn’t recyclable locally. It can ultimately contaminate the recycling bin, Hedlund said.

Education would also help consumers make more eco-friendly choices. Since metal is more likely to be recycled than glass, “I’ve made sure that most of my adult beverages are in aluminum cans and not in glass bottles,” said Robert Klee, the former commissioner of Connecticut’s Department of Energy and Environmental Protection. He suggested choosing metal containers over glass bottles when possible.

Most people I talked to pointed out that the most impactful action an individual can take — even more so than recycling correctly — is reducing consumption.

On a legislative level, these experts seemed unhappy with the American recycling system. “A lot of places elsewhere in the world have figured this out, so we’re behind,” Klee said. 

Atkinson, Klee and Yang proposed methods for perfecting the sorting process. Atkinson and Klee were enthusiastic about an expanded bottle deposit system to remove contamination and get cleaner end products. Atkinson recommended adding wine bottles to the program, noting how problematic glass is in sorting facilities. Klee suggested making deposit programs more convenient, using Oregon as an example. There, places to return bottles are common and one can get deposit redemptions on a gift card, he said. Yang offered that Americans should imitate the thoughtfulness with which many Europeans sort their recyclables at home, though she acknowledged the improbability of this change.

Klee went further with his recommendations. He explained that some regions, like British Columbia, optimize their recycling systems by combining resources across subregions and using a more centralized approach. States, in our case, could share recycling facilities, and in doing so increase sorting efficiency and strengthen public messaging.

I wasn’t able to find a clear consensus on what future improvements to legislation should be. Each suggestion seemed promising but had its major hurdles. While the field deliberates, though, I can do my part for the environment — and you, yours — by recycling attentively. 

TL;DR: I will keep cleaning my peanut butter jars, but maybe with a little less vigor.