A San Diego startup says it's made the world's first 100% biodegradable sneaker — and that most of the competition is greenwashing. But what does it mean to be "biodegradable"? And are biodegradable plastics really better for the planet? We tested six brands' claims and explore why it's so hard to make an environmentally friendly shoe.
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00:00Making a modern shoe that's fully biodegradable has been nearly impossible, even for major corporations.
00:07Big brands like Adidas have used stuff like ocean plastic to make their sneakers better for the environment.
00:13But those, like the 24 billion other pairs we make each year, are really difficult to recycle and will likely end up in a landfill.
00:21After six years of trying, this San Diego startup says they've made a shoe that actually completely breaks down.
00:28It biodegrades in soil, it biodegrades in compost, it biodegrades in the ocean.
00:33And the founders say most competitors who claim to have done the same are greenwashing.
00:37We get lots of products that people say biodegrade. We test them in here and it turns out they don't.
00:43So why is it so hard to make a biodegradable shoe? And can these products solve plastic pollution or will they make it worse?
00:51If an item is truly biodegradable, bacteria and fungi will want to chow down on it until only natural material, water and carbon dioxide are left.
01:00But they don't exactly have tiny mouths to chew it up. Instead, they release enzymes, which break it apart at the molecular level,
01:07into simpler elements that the microorganisms can absorb and digest.
01:11Conventional plastics, made from fossil fuels, take centuries to biodegrade because they're just too new.
01:17Most microorganisms haven't yet evolved to break down their long chains of strong bonds.
01:23But it is possible to make biodegradable plastics from fossil fuels by engineering the molecules to be easier to break apart.
01:30The main challenge for scientists has been making biodegradable plastics that microbes can digest once they're thrown out,
01:37but that stay strong and durable while humans are using them.
01:40Steve Mayfield and his team of researchers have been putting supposedly biodegradable products to the test for more than four years.
01:49Here's one of our little leather samples. So this is from a very famous fashion house in Italy.
01:54Oh, we have biodegradable leather. Five months later, it looked like this. It has clearly not biodegraded.
02:01In 2020, Steve and his team invented biodegradable foam made with algae, which they turned into flip-flops.
02:08But producing a full sneaker requires a lot more than just foam.
02:12If you look at a shoe, it's actually a surprisingly complex object, right?
02:17In fact, your typical sneaker can contain dozens of different materials.
02:21It might have a mesh upper made of polyester, faux leather detailing, hard plastic eyelets,
02:26an insole made of neoprene, a foam midsole, and a cushy rubber-like outsole made of ethyl vinyl acetate.
02:32In other words, many different types of plastic.
02:36Making the BlueView shoe meant reinventing sneakers from the sole up down to the smallest detail.
02:42The end of the little ties, quite often those are made with plastic.
02:47Now, their shoes are made at commercial scale in Indonesia, in a factory that makes shoes for brands around the globe.
02:54The owner, Anthony Saleem, has been in the shoe business for 15 years.
02:58But he'd never made anything biodegradable before partnering with BlueView.
03:02This has been the most innovative and daring project that we have ever been with.
03:08The first challenge was making fabric strong enough to support the top of the shoe without using conventional plastics like nylon.
03:16You want a shoe that looks like this. You don't want a shoe that looks like that, all collapsed.
03:22So we had to buy our own knitting machines and then learn how to program them in such a way that the material itself would stand up on its own, right?
03:31And that actually took six months, I hate to say it, but that took a lot of time and a lot of work.
03:37Now they weave together fabric made from hemp and tensile, which is a partially synthetic fabric made from wood pulp.
03:44The hardest part of the design is the knitting process. The style is particularly unique and it's never done before.
03:52To provide more stability, they also add a heel counter made of biodegradable polyurethane, a versatile form of plastic found in all kinds of products like kitchen sponges and the shiny coating on cars.
04:03On the stitching line, workers sew the upper to a board made of jute, a plant whose golden fibers are commonly woven into sacks across South Asia.
04:12Elsewhere in the plant, workers mix the ingredients to make the foam that will become the sole.
04:21That's the trickiest part to make biodegradable because it's specially engineered to be comfortable and durable.
04:27Most shoes use polyurethane foam made by mixing together two types of chemicals, both of which are typically derived from fossil fuels.
04:35Steve and his team figured out how to replace one of them with plant oils like jatropha or castor oil.
04:41The team does a quick test pour to check how much the foam rises and how fast it solidifies.
04:47Then they prep the molds and begin pouring.
04:54To complete the layered sole, they pour white foam on top of the blue treads.
05:04Finally, it's time to glue the two parts together.
05:08The glue is imported from Germany and was also tested in San Diego to make sure it biodegrades.
05:14It's heat activated, so a lamp warms it up before the two parts are pressed together.
05:19The final touch is a decorative strap made of cotton canvas.
05:22It's cut, stitched with cotton thread, checked under a light, and tied to the shoe using short laces.
05:28The final product uses materials imported from seven different countries.
05:35Blueview says it knows its product is biodegradable because the team tests it regularly.
05:40So here's our shoe at day zero, right?
05:43Here it is at one month.
05:45Here it is at three months.
05:46And here you can see that the upper degrades faster than our polyurethane bottom.
05:52We asked Steve and his team to put their shoes to test on camera alongside six competitor shoes marketed as sustainable.
06:01At the lab, they started by taking a before photo of each shoe.
06:06We're going to go ahead and take four images per shoe so we can get as many of these surfaces as possible.
06:15The team fills a container with moist compost.
06:17This is plant waste from farms which has already been digested by microorganisms.
06:22There's nothing gross going on in here, just a bunch of happy microbes living in their little lives.
06:29It's packed with natural bacteria, which give all the samples a better chance of breaking down.
06:34The team fills up each shoe and buries it with the mixture, plus more water.
06:38We'll take our water and we'll go ahead and we'll simulate a little rain shower for this compost pile,
06:43just so that way everything is nice and hydrated.
06:48This cabinet keeps it all at about 113 degrees Fahrenheit.
06:52And this incubator will keep the temperature consistent with what your average home compost pile would be like.
07:00They check on these samples every week.
07:03I started reporting on this story in 2023.
07:06BlueView and I waited more than a year to see how much the samples degraded in compost.
07:10Here's how the results measured up against the brand's claims.
07:13Besides BlueView, we tested Allbirds, Orba, Native, Rackle Shoes, Johnny Footwear, and Unless Collective.
07:20Three of them claim or heavily imply on their sites that their shoes are fully biodegradable.
07:26Two others made more nuanced claims about partial biodegradation of the foam soles only in specific conditions.
07:32And the others say the shoes are plant-based but don't mention biodegradability.
07:37After this test, only three of the seven shoes had clear signs of biodegradation.
07:42Here they are at 29 weeks and 59 weeks.
07:45BlueView's shoe was by far the most degraded,
07:48but it wasn't completely gone.
07:50Steve estimates it would take a few more months for that to happen.
07:53And prior testing from an outside lab found the foam used for the soles was 90% biodegraded in 219 days.
08:01Four of the seven shoes stayed almost completely intact.
08:05Including one by Johnny Footwear, a $150 sneaker the brand claims is biodegradable.
08:10The website also says it comes with an apple seed that would supposedly grow into a tree,
08:15encouraging buyers to bury their used shoes in the ground.
08:19This is the area where the apple seed should be.
08:22And if you look inside the shoe, there is a little flap and there is no seed in that little flap.
08:29It's important to note, for this biodegradation comparison, BlueView was testing its own competitors.
08:35Some of the brands claimed their shoes take three to five years to break down,
08:38and we weren't able to run a test that long.
08:40So this isn't perfect science.
08:42But the results are still revealing in terms of what can happen to shoes marketed as environmentally friendly at the end of their life cycles.
08:48Most of them will stick around for a long time.
08:51I reached out to all the brands tested for comment on these results.
08:54Two got back to me.
08:55Allbirds said it prioritizes carbon reduction and that it doesn't claim its shoes are fully biodegradable.
09:00Orba said optimizing biodegradation of its shoe requires it to be shredded and put in soil without any toxins.
09:06In addition to biodegradation, the shoes were also tested for biocontent.
09:10That's the amount made of biological materials.
09:13So that's plants, animals, fungi, as opposed to fossil fuels.
09:16Every shoe tested was marketed as bio or plant-based,
09:19mentioning materials like flax, coconut, sugarcane, algae, and other plants.
09:23But this is one of the trickiest types of green labeling.
09:26Just because something is plant-based doesn't mean it's 100% made of plants,
09:30but not every consumer knows that.
09:32And it's easy to mix up bio-based and biodegradable.
09:37Something bio-based is made of natural material like plants,
09:40but you can start with natural material and make something that's not biodegradable.
09:44Just look at leather.
09:45It's animal skin, but it's typically not biodegradable because of the chemicals that are not biodegradable.
09:48Likewise, you can turn fossil fuels into something that is not biodegradable,
09:53that's basically all conventional plastics,
09:55but you can also turn fossil fuels into biodegradable plastic.
09:59So something bio-based is not necessarily biodegradable,
10:02and something biodegradable is not necessarily biobased.
10:05Confusing, right?
10:06That's why it was important to test for biocontent separately.
10:09The Blueview team cut off samples of the seven shoes' soles,
10:14the most difficult part to make without fossil fuels,
10:16and sent them off to Beta Analytic.
10:19It's a third-party lab with no business ties to any of the shoe brands.
10:23And the results were all over the map.
10:25At the low end, the sole from Johnny Footwear had a biocontent of 0%,
10:30meaning it was entirely made of fossil fuels.
10:32Rackle's shoes had 1% biocontent, and Natives had 15%.
10:37Allbirds and Blueview were somewhere in the middle, with 32% and 49% respectively.
10:42And in the top two slots, Orba with 96%,
10:45and Unless Collective with 100% biocontent.
10:49The foam sole on Blueview's shoe is about half made of plants,
10:53and the rest fossil fuels.
10:55In 2023, Blueview's parent company got a $5 million grant from the Department of Energy
11:00to figure out how to make its foam formula 100% plant-based.
11:03Steve says his team's already done that, but they're not making it at a commercial scale yet.
11:08Even if Blueview manages to scale, there's still the problem of consumer confusion.
11:12Biodegradability is a term which I call it used and abused a lot.
11:20It's easy to abuse the biodegradable label for two reasons.
11:23One, it's not that well-regulated.
11:25And two, just about everything will biodegrade eventually,
11:28if you're willing to wait thousands of years.
11:30It all will biodegrade.
11:32It's a question of how fast, how slow, and what should be our way of handling it.
11:38If a product is marketed as biodegradable, but doesn't specify at what temperature or how long it will take,
11:44that's a red flag for consumers.
11:46To make things even more confusing, biodegradable and compostable mean different things.
11:54Biodegradable is a relatively broad term,
11:59while compostable is narrower and has specific legal definitions that vary around the world.
12:03In California, the home of Blueview, compostable means that the product totally biodegrades in under 180 days,
12:09or about six months, in a home compost bin.
12:12In a similar environment, Steve says a Blueview shoe will break down in about 14 months.
12:16All this confusion is part of why some experts don't want brands to market products as biodegradable at all,
12:22regardless of whether it's true.
12:24They also worry that if consumers think something is biodegradable, they might think it's okay to litter.
12:28Some say brands selling biodegradable items should have take-back programs to make sure they're properly composted.
12:35If you cannot ensure the shoes to be completely biodegraded in an industrial composting system,
12:45then you have not really achieved much.
12:48Biodegradable products don't just disappear instantly.
12:51So if they end up in nature, they can still cause problems as they break down.
12:55So fishes can eat it.
12:57Marine life can interact with it.
13:00Good, bad, we don't know.
13:02But it will interact.
13:03All that said, truly biodegradable products still have some environmental advantages.
13:08Even before you toss them out,
13:10plastic shoes leave behind a trail of microplastics as the soles wear down.
13:14Studies published in 2022 found these fragments can leach toxic chemicals into water
13:19and hinder plant growth in soil.
13:22Other research has found microplastics basically everywhere.
13:25In nature, in food, and in our bodies.
13:28In 2024, the Blueview team published a peer-reviewed paper showing its product does not create persistent microplastics
13:34as it breaks apart and biodegrades.
13:37Steve founded Blueview along with Tom Cook, who's worked in the shoe industry for more than two decades.
13:43We've got to stop the production of these toxic materials.
13:48We have to turn off the tap on forever plastics.
13:52Blueview is working on licensing its formula to other plastic heavy industries too.
13:57But we're quickly going to expand into apparel and accessories with coated fabrics.
14:02Our primary focus at this point is on selling the materials to other brands.
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