Curriculum · Animals & Fashion

Leather & Fur: The Hidden Cost

Your school shoes, that belt in your wardrobe, maybe the seats in your family's car — leather is everywhere, and so is the chemistry that made it. Today we're following a hide from the farm to the tannery to find out what the journey really costs. 🧪

The Chemistry Hiding in Your Leather Jacket

Raw animal hide has a problem: it's skin, and skin rots. Tanning is the ancient fix — a chemical process that permanently changes the proteins in a hide so it becomes durable, flexible leather instead of something decomposing in your wardrobe.

For thousands of years, humans tanned hides slowly using tannins — bitter plant compounds found in tree bark, leaves, and pods. Then, in the 1800s, chemists discovered that chromium salts could do the same job dramatically faster. Today, an estimated 85-90% of the world's leather is chrome-tanned. A hide that would take weeks or months in a pit of oak bark can be chrome-tanned in about a day, and the result is soft, stretchy, and water-resistant.

Here's the catch. Chrome tanning uses chromium(III), which is fairly harmless on its own. But under the wrong conditions — heat, the wrong acidity — it can convert into chromium(VI), a proven carcinogen. Well-run tanneries manage this carefully and treat their wastewater. Badly run ones don't.

Vegetable tanning still exists, making up roughly 10% of leather. It's slower and pricier, and it's prized for quality belts and bags — but its waste is far less toxic.

Hazaribagh and Kanpur: When It Goes Wrong

For decades, the Hazaribagh district of Dhaka, Bangladesh, packed around 150 tanneries into one crowded neighbourhood. A 2012 Human Rights Watch report called 'Toxic Tanneries' documented workers — including children — handling chromium and acids without gloves or masks, and suffering skin diseases and breathing problems. The tanneries pumped roughly 21,000 cubic metres of untreated wastewater into the Buriganga River every single day. In 2013, the Blacksmith Institute (an environmental group now called Pure Earth) ranked Hazaribagh among the most polluted places on Earth.

Bangladesh finally relocated the tanneries to a new industrial zone at Savar in 2017 — though journalists have reported that the new site's water treatment has struggled too.

Kanpur, in India, tells a similar story. Hundreds of tanneries there sit along the Ganges, a river sacred to over a billion people. Studies have found chromium in the local groundwater at levels far above safety limits, and farmland irrigated with tannery wastewater.

None of this means leather is evil. It means the price tag on a cheap leather item sometimes doesn't include the full bill — and someone living downstream is paying the rest.

Fur Falls — and the Vegan Leather Puzzle

Fur has had one of the fastest falls from grace in fashion history. Most fur doesn't come from the wild; it comes from farms where mink and foxes live in small wire cages. That reality, made visible by decades of campaigning, gradually turned the public — and then the law.

The UK passed a ban on fur farming in 2000, and the last farms closed by early 2003. Since then, roughly 20 European countries have banned it or begun phasing it out. In 2020, Denmark — then the world's biggest mink producer — culled its entire farmed mink population, estimated at 15-17 million animals, after COVID-19 spread through the farms. In 2021, Israel became the first country to ban fur sales altogether.

Fashion followed: Gucci went fur-free in 2017, Chanel dropped fur and exotic skins in 2018, Prada in 2019.

So should leather go the same way? Honestly — it's complicated. Most 'vegan leather' is polyurethane, a fossil-fuel plastic that never biodegrades. Real leather is mostly a co-product of the meat industry, though cattle ranching is a leading driver of Amazon deforestation. Newer plant-based materials made from cactus, pineapple, or mushrooms are promising, but often still contain plastic binders. There's no perfect option — only trade-offs.

What a Thoughtful Shopper Can Actually Do

You don't need to fix tannery chemistry from your bedroom. But you have more power here than you might think.

First: second-hand leather is arguably the most sustainable leather there is. The animal impact and tanning pollution happened years ago — buying used doesn't fund more of it, and leather is one of the few materials that genuinely improves with age. WRAP, a UK waste research group, has estimated that keeping clothes in use just nine months longer cuts their carbon, water, and waste footprints by around 20-30%.

Second: if you're buying new, check the claims. 'Vegetable-tanned' and 'chrome-free' actually mean something, and the Leather Working Group audits tanneries on their environmental practices. If you're using the Rewoven app, the Animal Welfare and Environmental grades do some of that digging for you when you scan a label.

Third: care for what you own. Keep leather dry, condition it occasionally, and get shoes resoled instead of binned — a good leather jacket can outlast your phone by twenty years. And a local twist: the UAE makes leather too. Abu Dhabi is home to a tannery that specialises in camel hides.

Key takeaways

  • Around 85-90% of the world's leather is chrome-tanned because it's fast and cheap — but poorly run tanneries can release toxic chromium into rivers and groundwater.
  • Hazaribagh in Dhaka and the Kanpur tanneries on the Ganges are documented cases of tannery pollution harming workers and whole communities.
  • Fur farming is collapsing: roughly 20 European countries have banned it, and houses like Gucci, Chanel, and Prada have gone fur-free.
  • 'Vegan leather' is usually polyurethane plastic, so it isn't automatically the greener choice — every material comes with trade-offs.
  • The most sustainable leather is usually second-hand leather that's cared for well enough to last decades.

Try this

The Home Leather Census

Walk through your home and count every leather item you can find — shoes, belts, bags, wallets, maybe a sofa. Note roughly how old each one is and what condition it's in. You'll probably notice the oldest items are holding up surprisingly well for their age. That durability is leather's superpower, and it's central to this whole debate.

The Oldest Item Interview

Ask a parent or grandparent to show you the oldest leather item they own and tell you its story — where they got it, what it's survived, whether it's ever been repaired. Then ask what they think about fur, and whether their opinion has changed over their lifetime. Compare their answers with your own views and see where you land differently.

Vegan Leather Detective

Pick any online clothing store and find a product labelled 'vegan leather.' Dig through the description and materials list to work out what it's actually made of — polyurethane, PVC, or a plant-based blend. Then find a real-leather product and check whether it says anything at all about how it was tanned. Notice how hard honest information is to find.

End-of-lesson question

Most 'vegan leather' sold today is actually made of what?

The vast majority of vegan leather on the market is polyurethane (PU) or sometimes PVC — plastics made from fossil fuels that don't biodegrade and often wear out faster than real leather. Plant-based options made from pineapple leaves, cactus, or mushroom mycelium do exist and are genuinely exciting, but they're still rare and usually contain plastic binders too.