Are Mushrooms the Answer to the Global Plastic Crisis?

Happy Monday! Welcome to another edition of The Drop In, DoubleBlind’s newsletter delivering independent journalism about psychedelics straight to your inbox.

Today’s lead story is about the fabled plastic-eating mushrooms. We’ve searched high and low for experts to talk to us about practical applications of these mushrooms and how they can be scaled or brought to the public in ways that make an impact. It’s taken us a long time to find people putting money where the mycelium is. But after some bumbling around on the internet, we finally came upon someone. You’ll have to read more below to find out what’s up!

If you keep scrolling, you’ll find stories about the Huatla mushroom, a breakdown on Ayahuasca art, the Vikings’ relationship to Amanitas, and so much more.

Happy fall 🍂,
Mary Carreón
Editor-in-Chief

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Can Fungi Help Tackle Our Massive Diaper Waste Problem?

We’ve heard of plastic-eating mushrooms, but what about diaper-eating ones? One company says it’s using fungi to tackle the world’s diaper waste problem, and, in turn, the global plastic crisis.

We’ve all heard of the fabled plastic-eating mushroom and the wild fungi thriving in Chernobyl’s radioactive soil, hinting at how mushrooms might one day help heal toxic soil. But now, there’s a company using mycelium to decompose used diapers. It’s called HIRO, and it’s a brilliant, sustainability-focused startup co-founded by mushroom entrepreneur Tero Isokauppila, who founded Four Sigmatic, and Miki Agrawal, the co-founder of THINX period-proof underwear. HIRO aims to use fungi to break down soiled disposable diapers, which are a major source of global plastic waste. The idea sounds almost mythical, but it is grounded in science and could mark a new frontier for mycoremediation and tackling the plastic crisis.

For Tero, this venture is a natural evolution of his life’s work. He has spent much of his life and career thinking about mushrooms, and comes from a long lineage of farmers. “I studied chemistry and nutrition, and that inspired me to get into the [functional mushroom and mycology] worlds through health wellness, and then later, psychedelics,” Tero told DoubleBlind over the phone. He even advises the first legal psilocybin retreat center in the Netherlands.

But functional, or non-psychedelic, mushrooms were just the beginning for Tero. He has since become increasingly drawn to the potential of fungi for environmental remediation.

“Along the way, I obviously was also exposed to the environmental potential of mushrooms and mycoremediation,” he said. (Full disclosure: Tero has since stepped back from HIRO but remains one of the largest shareholders.) “And what I know is that certain fungal species [are] able to break down the plastic polymers of diapers.”

Miki originally came up with the idea of creating a business around diapers that decompose by mycelial force. “She came to me in 2020 and said that she’s been working on this for a couple of years with other people. She said she thinks it will be huge,” Tero said.

But he was skeptical at first — that is, until his wife gave birth to their first son in 2021. Suddenly, he was changing nearly 14 diapers a day. “I didn’t realize how massive this [waste] problem is. Diapers are the number one household plastic waste item. At that point, I told [Miki], ‘Okay, I’m in. Let’s do it. The world needs this, right?’”

According to the Environmental Protection Agency (EPA), infant and adult disposable diapers generated 4.1 million tons of solid waste in the United States in 2018. And that’s just weight! And seven years ago! Other studies estimate that 27 billion soiled disposable diapers end up in U.S. landfills each year.

“Every disposable diaper ever created is still sitting in a landfill today,” Tero said. “By solving the diaper problem, we can also solve most consumer plastic issues in the future. So it was like an Archimedes lever. If we can do the diaper, we can do almost any [type of waste].”

HIRO’s research draws from over a decade of scientific inquiry into plastic-eating fungi, beginning with a discovery by Yale undergraduates that revealed 34 mushroom species capable of breaking down plastic polymers. “We tested 34 [mycelium] species, and along the way, we’ve added a couple more dozen. So we’ve tested dozens and dozens of types [of fungi]. When we started commercializing, we took the top five that we’ve now been working with the most” that show the most efficacy. This mycelial concoction is what he calls a “superhero fungal blend.” We asked Tero which mushrooms were in the blend, but he said it was proprietary.

The public, however, has been skeptical of the concept of plastic-eating mushrooms. “Outside of academia, there was a popular TED Talk where it was mentioned that [the] oyster mushroom would break down diesel,” Tero said. The talk, popularized by a famous mycologist, drew headlines but was based on inconclusive research. “People who actually read the study were disappointed.”

Yet, subsequent studies from top universities have repeatedly demonstrated fungi’s capacity to degrade plastics. “I think anybody denying it [at this] point is kind of like a flat-earth person, because the data is so abundant and broad.”

Still, the real challenge lies in scaling a concept like this, Tero said. “The problem that has not been solved yet is, how do you commercialize these things? How do you bring them into the world effectively and scale them?” 

The company’s diapers launched this past April, with a $119-per-month subscription or a one-time cost of $136, which includes six packs of unbleached diapers (or one month’s worth), a month’s supply of HIRO fungi pouches, and four packs of water-based wipes. This is a steep price tag for many parents, especially when diapers at Costco can cost roughly $60 and wipes $30 for a month’s supply. A $29 price difference is significant to many families in the U.S. today. But when you consider sustainability factors — such as unbleached diapers, fewer chemicals in water-based wipes, and mycelium that decomposes stubborn plastics — $119 (or $136) doesn’t sound so bad.

Plus, the company's big vision extends far beyond baby care: Eventually, they hope the mycelium will be able to digest other common plastics in landfills, not only eliminating diapers but also entire mounds of plastic waste. In other words, the mycelium used in the diapers will ideally continue colonizing in landfills even after a diaper has decomposed.

Normal diapers take 450 to 500 years to decompose, according to the journal Science of the Total Environment, but Tero believes HIRO’s fungal blend will break them down much more quickly, potentially within several months to a couple of years, rather than centuries. The science, he stresses, takes time to replicate across different climates and conditions, however. But the momentum is undeniable.

“We cannot yet make a compostability claim around how fast the diapers will decompose because even though we have studies to show sub one year degradation, we need to be able to replicate that in all conditions within one standard deviation,” Tero told Doubleblind. “So we’re not ready to give a timeframe, but we are very, very confident that it will be at least 10 times better [and faster] than the current solutions.”

The implications here are undeniably huge. HIRO’s vision shows how nature’s smallest organisms could help redefine how we manage waste and restore meaning to the word “sustainability,” a term that’s been rendered meaningless by greenwashing. At a time when environmental progress can feel stagnant, projects like HIRO offer a rare glimpse of hope for the future.

Sneak Peek

Reckoning With the Reality of Mushroom Dispensary Robberies

Across Canada’s biggest city, a rash of shootings, arsons, and hit-and-runs has turned Toronto’s gray-market mushroom dispensaries into crime scenes. Behind the shattered glass and singed storefronts lies a murky underworld of anonymous owners, cash-only empires, and escalating turf wars. As psychedelic reform stalls, a trip meant to dissolve egos is instead igniting them. Journalist Mattha Busby has the latest.

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DoubleBlind Digs

• Looking to attend a psychedelic event? Head to PhilaDelic 2025, a one-day symposium at the Perelman School of Medicine exploring how psychedelic therapies can address addiction and mental illness. Learn more here.

• Join Zach Leary on October 30 at 6 p.m. CT for Addiction: From Dark to Light, a live Zoom talk exploring how psychedelics might help treat addiction, followed by a Q&A. Scroll to the bottom and subscribe to his email list to get the Zoom link.

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