Here's what happens to old shoes and how mass production deals with waste
How many pairs of shoes do you own? Do you only buy new ones when your old ones are falling apart?
It turns out that the production and disposal of shoes globally is not the most environmentally-friendly practice. Far from it, with cheaper shoes being some of the worst culprits.
But, what, if anything, can be done? Is it really a problem? After all, most of us need shoes, don't we?
What are modern shoes made of?
Most modern shoes are mass-produced in specialist factories in various countries around the world. Most of the larger brands, like Nike, for example, outsource their production to countries in Asia like China, Vietnam, Indonesia, Malaysia, Pakistan, India, and Thailand.
The process and materials involved do vary depending on the brand and shoe and will require equally variable machines and equipment. Some shoes, especially those with more complex designs, can require over 400 steps or more to complete from start to finish.
That being said, most shoes will consist of a series of basic components like a sole, insole, outsole, midsole, heel, and upper. Depending upon specific designs, shoes may also contain a lining, tongue, quarter, welt, or backstay.
Each of these components will usually require a specialist machine to fabricate and assemble, as well as pair up shoes to make a pair prior to boxing and shipping. Despite the number of steps and materials involved, a pair of shoes can be manufactured much more quickly in a factory than by hand.
In addition to the use of energy, water, and other resources, some types of shoes, such as sneakers, also tend to use materials made of harmful chemicals that can, and often are, released into the environment in areas with less-than-perfect environmental governance.
Modern shoe-making facilities will usually divide up the different steps into separate departments within the facility and may also outsource some parts of the process too, like sourcing insoles from specialist manufacturers instead of making them in situ.
Each department will typically bear a designation that reflects the specific tasks they perform, such as designing, cutting, machining, sewing, assembling, and finishing. While many different machines perform specialized tasks, many workers are also essential to making the process run smoothly.
Modern shoes can consist of a surprisingly large array of materials too. Leather, plastic, cloth, and rubber are some of the most common. However, many shoes will also incorporate some more advanced materials like ethylene vinyl acetate, polyurethane foam, and gel or liquid silicone.
Most of these materials are excellent at doing their job in terms of the use the shoe is put to, but are all too often incredibly difficult to recover or reuse once the shoe has reached the end of its life, especially since recycling often involves separating out the various materials.
How long does a typical pair of shoes last?
While quality is very important in a shoe, especially for high-performance athletics shoes, for most types of shoes today, quantity tends to win out, especially from a business perspective.
This is primarily due to the wonders of mass production. While this has enabled prices for shoes to fall considerably over time, it has also led to a noticeable decrease in the longevity of a pair of shoes.
Traditionally, shoes were made by hand by skilled craftsmen and were made of relatively robust and long-lasting materials like leather. In fact, some of the oldest surviving footwear in the world can actually be dated back to ancient Egypt around 1500BC.
While technically a pair of overshoes, one pair of such shoes in the British Victoria and Albert Museum were made from woven reeds and are still probably useable today. Though, of course, no one would ever dare try them out.
Of course, such examples are very much the exception to the rule, as the vast majority of older footwear was made from natural materials that will rot and decay over time. However, that being said, a well-made pair of leather shoes or boots can, and often will, last a lifetime if properly cared for and maintained.
It is a rather sad fact that modern shoes tend to be made of synthetic materials that should last much longer than they do, but they are not designed to be repaired and their relative cheapness and style of craftsmanship often mean that they can be more expensive to throw them away and buy a new pair than to have them repaired.
We won't get into a tempestuous discussion on esoteric concepts like consumerism, but needless to say that it's obvious shoes aren't made like they used to be.
Modern footwear, according to some sources, typically only lasts between 8 and 12 months for most people, or around 500 to 700 kilometers, give or take. Of course, shoes used by professional athletes and children's shoes are often changed more frequently, but this is obviously more of a product of tremendous wear and tear and of growing little feet.
Of course, the lifespan of most shoes can be improved considerably if they are well looked after, for example, if they are treated with water repellent when required. If people take the time and investment to look after their shoes, a pair of non-athletic shoes should be able to last at least 5, perhaps even 15 years.
But, once again, the relatively low cost of most modern footwear offers little incentive to do so. But, this really is a shame because constantly replacing a pair of shoes every 8 to 12 months is often a false economy.
If you spend more money on a good-quality pair of shoes, they can, and will, last you much longer than several pairs of cheaper ones. Often this will also save you a pretty penny over the long term.
They may not be in fashion all that time, but good footwear is never a bad investment. And some styles are relatively timeless. Unless, of course, you actually enjoy walking around barefoot.
On that subject, and please forgive us for the momentary diversion, there might actually be some important benefits to walking barefoot as much as you can. Since this is the natural state of our body (after all, shoes are a relatively new invention), walking barefoot may greatly improve body flexibility and agility.
It may also have some important benefits for ligament and muscle strength and function, improves your posture, and can even reduce your likelihood of getting foot and lower leg injuries. Of course, humans also did not evolve to be walking on concrete, so barefoot may be better only when on a natural surface.
And were are back.
While cheaper shoes often need replacing more often, there will also be a time when even the best quality pair of shoes needs to be replaced. So, this leaves the question about what actually happens to those shoes we throw away?
Where do shoes go when they die?
For the vast majority of shoes, like most waste, you won't be surprised to hear that they are simply tossed away and eventually buried in landfills. And the problem is huge.
According to some sources, in the United States alone, 300 million pairs of shoes, give or take, are thrown away each year. That is a lot, but what is even more shocking, is that there are around a similar number of children around the world who have never owned a pair of shoes in their lives.
The materials used to make shoes can take a long time to decompose, staying in the ground without breaking down for between 30 and 40 years!
And this is not just a problem for synthetic materials. Even natural ones like leather can take around 50 years, or so, to rot away completely.
Some components could even hang around underground for the better part of a millennium. Other shoe waste management strategies involve simply burning old shoes in order to dispose of them.
This practice is obviously not the best for the environment and tends to lead to the release of many toxic chemicals into the atmosphere.
For the vast majority of old shoes, these are the most common final destinations, but we are starting to see an explosion in methods for recycling or reusing old shoes, too - as you are about to find out.
How can we make shoes more environmentally friendly?
As we've seen, modern shoe production and waste management are desperately wasteful and potentially pretty harmful to the environment. Like many other products made, there are a few options that tend to range from reducing their production (not realistic), reusing existing shoes, finding more sustainable raw materials to make them from, or, of course, partially or completely recycling them.
So, what, if anything, are private and public organizations doing about it? Let's find out.
1. Adidas is on a mission to make their shoes from recycled materials
One major corporation attempting to help reduce their reliance on so-called "virgin polyester" and waste associated with shoes is Adidas. "Virgin polyester" is a term used to describe newly created plastic from raw materials.
Their "Primegreen" range, for example, is made from a series of high-performance recycled materials that, according to Adidas, "represents our commitment to phase out all virgin polyester by 2024 to help end plastic waste." It is a new fabric that also contains no virgin (or newly created) plastic. It is an integral part of the revamp of the legendary Stan Smith sneaker, replacing the sneaker’s virgin polyester material. A premium polyurethane coating sourced from Japan mimics the original tennis shoe’s leather feeling, while outsoles are made from recycled rubber, and laces are crafted from recycled fabric.
This series of products includes trainers, of course, but also a range of other sports and fashion clothing like tights, shorts, T-shirts, etc.
Adidas also has another range called "PrimeBlue" that uses high-performance yarn made from 50% ocean plastic sourced from the Parley Global Cleanup Network. This is mainly from upcycled plastic waste intercepted or collected on or near shorelines, coastal areas, etc, to help reduce plastic waste pollution.
Adidas is really pushing hard in this direction, with about 17 million pairs of shoes made from recycled materials.
2. This company specializes in recycling old shoes
A UK-based charity called Traid is helping do their part to divert old shoes away from simply being chucked into a landfill. A specialist garment recycling company, they collect discarded clothes and shoes in the UK from a variety of global suppliers.
According to Traid, shoes are now becoming increasingly harder to recycle as shoe consumption continues to rocket year on year.
“Shoes used to be 11% of all the stock we collected, 270–280 tonnes a year,” a Traid representative told the Guardian in an interview. “Now this has dropped to 6%. The quality has got worse, so people just throw them in the bin.”
Once discarded shoes are received by the company, they are sorted by color, style, climate, so-called "cultural suitability", and quality. With this complete, collected shoes are packaged up and shipped out across Europe, Africa, and Asia.
In the receiving countries, the shoes are then sold wholesale to warehouses that then sell them to local sellers. The exact shoes in each package are something of a lottery, but they are very popular in some parts of the world, like in Uganda.
While this business sounds pretty risk-free, after all their "raw" materials are often donated by the public, they do suffer from periodic raiding by organized gangs. At times, Traid says, they have had months where several tonnes of donated clothing and shoes are actually stolen from their warehouses.
3. Old shoes can be turned into new ones too
Adidas is not the only organization looking into turning old shoes into new. Shahin Rahimifard, professor of sustainable engineering at Loughborough University, for example, has spent the last 15 years or so looking into ways to do exactly the same thing.
Unlike Adidas, however, Professor Rahimifard has developed a method of simply "doing-up" old pairs of shoes with replacement parts and offering them for resale. The rationale is that if the old shoe, or shoes, only defect is a damaged or worn upper or sole, why not just replace those parts to create a "new" pair of shoes?
However, the new "upscaled," or rather refurbished, shoes haven't yet proved popular. A combination of fashion consciousness and/or worries about quality or contamination from bacteria, etc., has drastically reduced the potential number of buyers for such shoes.
This didn't put Rahimifard off, though. He developed another method that he has termed fragmentation. This is the systematic dismantling of an old shoe into its component parts and then splitting the components even further into their constituent materials.
These parts can then be turned into other new products like rubber chips bonded with resin. These materials, it turns out, are pretty good as an underlay for things like basketball courts or resurfacing athletic tracks.
4. This company turns old chewing gum into new shoes and wellies
One organization, called Gumdrop limited, has developed an innovative process to kill two birds with one stone. The first issue is to help clean up the streets of old chewing gum.
The second, and most important to this article, is what they can make from that gum; shoes!
Chewing gum litter is not only unsightly on the streets, seats, and parks around the world but is also a massive wasted potential. The material the gum is made from, resin, wax, and elastomer, can be repurposed as a raw material for making new things.
Spotting this opportunity, Gumdrop Limited was founded by Anna Bullus in 2009 "to tackle the global problem of chewing gum litter."
They are, according to their website, "the first company in the world to recycle and process chewing gum into a range of new compounds that can be used in the rubber and plastics industry. Make way for Gum-tec®."
Their process uses a closed-loop recycling process to make their products, which starts with their collection receptacles for used gum placed around cities. Called "Gumdrops", these bins are bright pink in color and provide a fun, colorful replacement for the common eyesore of the white splodge.
Whenever one of these bins is full, the whole Gumdrop bin, along with its contents of waste gum, is recycled and processed to manufacture new Gumdrops, and the cycle starts again.
Once collected, the company works with manufacturers and companies globally in order to offer innovative products made from recycled and processed chewing gum.
"With Gumdrop’s help, recycled and processed chewing gum can become a vast number of things from wellington boots to mobile phone covers, stationery, packaging, and much more. As well as being used as a more sustainable choice to virgin plastics," explains GumDrop Limited.
Now that is what we call a noble endeavor.
5. Nike is producing biodegradable shoes
Since we gave Nike some criticism earlier, it is only fair we highlight their initiative to create biodegradable sneakers. They are working on some new sneakers that will be both less polluting to the environment and completely biodegradable.
The shoes are being developed in conjunction with the biotech company Newlight, which has developed a process of converting carbon into a plastic or leather alternative. If successful, this could prove revolutionary for the sneaker industry.
Called AirCarbon, Newslight's innovative material is even technically carbon-negative (or it absorbs more carbon in its production than released).
"AirCarbon offers an opportunity to further reduce our impact on the planet," said Nike's Chief Sustainability Officer Noel Kinder, in a press release. "Materials account for 70 percent of Nike's total carbon footprint, and we're accelerating our efforts and exploring new opportunities in this space because, in the race against climate change, we can't wait for solutions, we have to work together and create them."
To manufacture its AirCarbon, Newlight extracts microorganisms from the oceans. These ingest oxygen and carbon and transform them inside their bodies into polyhydroxybutyrate, also known as PHB. The company then dries the PHB and turns it into a fine white powder that can then be melted to produce several useful forms, like sheets, fibers, and even solid shapes.
For now, research is continuing into how exactly to use AirCarbon in Nike shoes, but there are other products already on the market made from the stuff. One of them, Covalent, uses Newlight's AirCarbon to produce wallets, handbags, sunglasses, and tech accessories, while one company, Restore, manufactures AirCarbon cutlery and straws.
6. Self-repairing shoes might be the ticket?
One of the most common points of failure for any pair of shoes is the sole. Typically made from rubber, this material eventually wears out or is easily punctured over time, often meaning the shoes either need to be resoled or, in most cases, are simply thrown out, and a new pair is bought to replace them.
Interestingly, researchers at the University of Southern California Viterbi School of Engineering reported a few years ago that they may have developed a new kind of rubber that can actually self-repair. The material can be 3D-printed too.
This means that, if ever made commercially available, it could be made relatively cheaply and last much longer than more traditional rubber.
The secret behind the material is a process known as photopolymerization. This process uses light, either visible or ultraviolet, to solidify a liquid resin through a reaction with a chemical group called thiols. If you add an oxidizer to the equation, the thiols transform into disulfides, a chemical group that is able to self-repair.
All that remained was for the right ratio to be found to give the rubber its seemingly-magical properties.
"When we gradually increase the oxidant, the self-healing behavior becomes stronger, but the photopolymerization behavior becomes weaker," explained Assistant Professor Qiming Wang. "There is competition between these two behaviors. And eventually, we found the ratio that can enable both high self-healing and relatively rapid photopolymerization."
While still very much in its research and development phase, this self-healing rubber could prove revolutionary for the shoe industry.
7. These shoes are actually made from coffee beans
Another interesting strategy to help make shoes less harmful to the environment comes from a company called Rens. Like others mentioned above, Rens integrate recycled materials as much as possible within their products, like plastic, but they have also found a way to incorporate coffee waste, too.
This mixture of plastic and coffee is used to make their shoe uppers, but they also recycle other materials like polyester for their sock liners. The soles of the shoes are made from all-natural rubber too.
According to the manufacturer, each pair of their shoes is made from six recycled plastic bottles and around 150 grams of coffee waste. The latter is an excellent incentive, as somewhere in the region, 6,000,000 tons of coffee waste are usually just dumped into landfills every year.
This is not only wasteful but also leads to the release of the incredibly potent greenhouse gas methane. By finding a way to redirect coffee waste from landfills to make new shoes, Rens are really making a difference.
But, how do they use old coffee waste for shoes? Well, Rens have developed a process that turns used coffee grounds into a special thread that is both great at trapping odors and also happens to be naturally antibacterial.
"On top of smelling fresh," Rens explain, "our coffee yarn dries 200% faster than traditional athletic apparel, keeping your shoes dry inside and out."
8. Perhaps modular shoes are the way to go?
Since one of the major issues with keeping or reusing old shoes is the ebb and flow of fashion, then perhaps a good way to reduce each individual's purchase of shoes over their lifetime is to make them modular? By switching out parts of the shoe as they wear out, or fashion changes, then it might be possible for one pair of shoes, in theory at least, to last someone a lifetime.
And that is exactly what one company has managed to produce.
The modular shoes, called Shooz, successfully completed a round of crowdfunding back in 2016 for their line of customizable shoes. Each shoe works by maintaining the same sole and base structure, but outer skins can then be zipped on to change the footwear for any occasion.
"Shooz is made of a 'Skin' and a 'Sole' which is detachable and interchangeable and allow you to create a style that’s perfect for you and perfect for any occasion," explain the designers on their Kickstarter bid.
"Whether you’re traveling, biking, running, working, or just going out for a night on the town, you can carry around your flat-packed skins and customize Shooz to fit any occasion."
While it is clear this concept has not taken the shoe market by storm just yet, it is initiatives like this that, once popularized, could greatly help reduce waste within the shoe industry.
9. These sneakers are made from discarded fruit and veg
Another company, MoEA, has developed a process of turning fruit and vegetable waste into footwear. Advertised as "low-carbon" and "vegan-friendly", these sneakers come in a range of colors and sources, including apples, grapes, pineapple, cactus, and even corn.
The sneakers are a pan-European affair, including design and fabrication teams from France, Italy, and Portugal.
According to the company's Kickstarter page, they "pioneer and use bio-materials to replace leather and plastic that are planet killers. Science brings you the next generation of sneakers: sneakers made entirely from plants and recycled materials. MoEas are sustainable, PETA-approved vegan, and recyclable. Science meets Fashion."
The raw materials for their sneakers come from a range of sources including the wine industry in Italy where grape waste is turned into a "grape leather" ready for use in their footwear products. "Apple leather" is made from the waste products of the fruit juice industry in Italy, and American non-edible corn products are used to make their "Corn Leather".
Their "Cactus Leather" is sourced from Mexico, and the raw materials for their "Pineapple Leather" come from the Philippines.
To make their leather, MoEa takes the plant waste, then colors and mixes the biomass with stabilizers like organic cotton, bio-PU, or recycled plastic, depending on the plant. Discarded fruit and veg biomass typically make up around 49% of the total final product.
According to the company, MoEa sneakers have also been extensively tested and have been found to be robust and durable as leather:
- Abrasion resistance tests on bio-materials have shown their robustness: MoEa abrasion resistance > 50.000 cycles - like leathers.
- The soles are made from recycled and natural rubber, the most durable soles material.
- MoEa soles are sewn to the upper, so they never tear off.
10. These shoes are made from woven bamboo
Hot on the heels, so to speak, of other biomass-based shoes comes another made partially from woven bamboo. Developed in collaboration between ASICS and Kengo Kuma, woven bamboo shoes look great and are incredibly sustainable.
Bamboo, the largest of the grass family of plants, is one of the world's fastest-growing plants. Some species are even able to add 36 inches (910mm) to their height in less than 24 hours!
This makes them an excellent choice as a building material, or in this case, a raw material for consumer goods like shoes.
Called The "Metaride AMU," the woven bamboo shoes consist of several main parts. The sole is split into two parts. A tan midsole that is made of an ecologically-conscious wood-derived textile and a clean white outsole. A shock-absorbing material gel placed on the heel compliments a two-part OrthoLite and cork insole to enhance cushioning when landing.
Recycled polyester is used for the knitting that forms the base layer, and a cork insole is both complementary to the "Sahara Desert treatment" and a more sustainable alternative to typical materials.
11. You can also recycle/upcycle/repurpose your old shoes at home
So far, we've seen some options that various public and commercial organizations are using to make old footwear less harmful to the environment. But, there are also some options that you can try at home.
Rather than throwing them away, or donating them, there are many ideas that can be used to put those old shoes to use long after they've exhausted their utility as footwear. The limit to this is only really your imagination.
For example, old shoes can be used as plant pots, jewelry racks, works of art, etc. Depending on the material they are made of, you could even dismantle them and turn them into new items like bags, etc.
You can even turn old boots into birdhouses - just make sure you clean them first. You don't want to scare off birds because of smelly feet!
Old high-heeled shoes can make excellent planters, bookends, lamps, etc. Old flip flops are also pretty useful for making toys, gaskets, fly curtains, etc.
We are confident you can come up with some equally innovative uses for your old shoes too.
And with that dear readers, is your lot for today.
As you can see, the mass production of shoes has made them more affordable than ever, but at the potential cost of the environment. May are made from a combination of synthetic materials that are economically unviable to recover, or technically difficult to do so (usually both).
That being said, many companies are now working on ways to make their products more sustainable by using more natural products or using old shoes as raw materials (to a greater or lesser extent). This is encouraging, and so long as consumers find such products appealing, we are confident the future of shoe production and end-of-life management will only get more efficient and innovative in the years to come.