Fashioning a circular future for traditional and alternative leather

The practice of turning animal skins into wearable goods dates back thousands of years. But until recently this global fashion industry largely followed a linear “take-make-waste” production model, with unsustainable tanning through finishing processes dependent on chromium salts and other polluting toxins, and requiring massive amounts of water.

Today, as the industry edges slowly toward circular principles, traditional leather products are being forced to compete with all manner of synthetics (some fossil fuel-derived), and others biobased (derived from sources as diverse as cacti and bananas, but often requiring plastic additives to achieve traditional leather’s durability).

No matter: leather in all its forms remains a growth industry. In 2023, it was valued at $460 billion globally, and expected to hit $700 billion in worth by 2030 as demand surges and the range of synthetic alternatives expands.

Against this booming backdrop, critics argue that using skins provided by the global livestock industry is responsible for a litany of environmental supply chain problems, starting on ranches, moving through tanneries, and extending to leather’s end of life.

Still, experts hold out hope that innovative circular solutions could create a far more sustainable traditional leather industry. Meanwhile, all manner of alternatives could lessen environmental harm, though these substitutes could come with their own cost, scaling, technical and environmental conundrums.

The limits of traditional leather’s circularity claims

Leather advocates contend that products derived from livestock skins are inherently circular, turning meat industry “waste” into a valuable fashion commodity. Industry representatives even point to tanning as one of the oldest examples of “upcycling,” or creative reuse, a pillar of the circular economy. Without leather production, they argue, many thousands of unutilized tons of hide would end up in landfills or incinerated.

“The majority of life-cycle assessment studies on leather production and use assume positive impact mainly because you are finding a reuse for a material that is often a byproduct of animal breeding,” notes Shahin Rahimifard, an industrial engineer and professor at the U.K.’s Loughborough University. “This assumption has swayed [views of] the overall environmental performance of leather because you are basically saying ‘if I didn’t use it, it goes into landfill.’”

Others argue that the meat and leather industries are inherently linked at the hip, that leather should be seen as a “co-product” of the meat industry — sharing in the mutual responsibility for environmental harm.

Aynur Mammadova, a researcher at Italy’s University of Padova, points out that the narrative portraying the leather industry as circular and sustainable ignores its links to environmental harm all along the fashion supply chain. This includes potential deforestation in cattle-ranching hotspots such as the Amazon, methane release during cattle rearing, heavy resource use and high levels of waste, serious pollution of water and air, along with animal welfare concerns. In her view, “every company that uses leather should understand the supply chain, where it comes from, and mitigate the risks.”

“The leather industry is as toxic to the planet as it is cruel to animals,” according to Yvonne Taylor, vice president of corporate projects at PETA, the animal rights NGO. Shaping skins into leather relies on the use of harmful chemicals, toxic mineral salts, and other harmful substances, she adds. “Tannery runoff contains large quantities of pollutants such as lime sludge, sulfides and acids.”

“Leather is not a ‘byproduct’ or ‘leftover’ of the meat industry, but a $100-billion industry in itself; it exists because of demand, not due to [meat industry] waste [reuse] concerns,” Taylor says.

Others believe the industry as a whole gets a hard rap and emphasize how it is changing. “Like many other industries, leather is an input-intensive industry. It does require a lot of chemicals, water, and energy,” says Fernando Bellese, WWF’s senior director of beef and leather supply chains. “If you’re not managing those things well it can lead to water pollution, air pollution, and so on.”

But he adds that not all producers follow polluting practices, and progress is being made in reducing impacts across some company supply chains. “If you look at the leading companies nowadays, they are very modern. They have high technology in terms of wastewater treatment, in terms of chemical management,” says Bellese.

There are “gradients of maturity” within the industry,” agrees Kim Sena, with Leather Naturally, an industry group. He points out that leather is far more durable than other fashion materials, slowing down textile consumption and disposal rates, if used wisely.

“But we have to think about other issues,” he agrees, such as animal welfare, cattle impacts, and leather-processing pollution.

Leather’s circular solutions

Implementing circular practices during production can reduce leather’s environmental burden, according to experts. Recovering, reusing and reducing waste is a first step, says Marika Gargano, a researcher at Italy’s University of Naples Federico II, whose work focuses on finding natural and biobased solutions within leather production.

A next step is “returning to original tanning methods,” using vegetable tanning instead of chrome-based tanning. A recent study, notes that while both techniques have impacts, circular-based vegetable tanning (also dubbed green tanning), achieves “substantial impact reductions” of toxins and released CO2, while saving water.

When it comes to post-tanning — the processing phase that gives leather its final color and texture — the current predominant chemical use can amount to a “bomb” for the environment, Gargano says, if released via wastewater. “We need to replace all these reactants with natural ones,” she says, which means “introducing enzymatic reactions, natural dyes, [and] proteins instead of [using] resins.”

However, significant barriers, especially involving cost, are impeding implementation of these sustainable solutions globally. Traditional leather is primarily produced in China, Brazil, Russia, India, Italy, South Korea, Argentina, and the U.S., all with varying levels of industrial sophistication, financial access, and environmental regulatory standards.

“The leather industry may [currently] lack the resources and support to establish a [circular economy] model,” says Sanjoy Paul, a researcher at Australia’s University of Technology Sydney.

Likewise, “The concept of reusing, repairing, refurbishing and recycling leather products [to extend their life cycles] has not been well-established in developing countries.”

In Paul’s view, a range of industry actions will be required globally to address its large environmental footprint. Alongside needed circular solutions, these include treating wastewater efficiently, minimizing toxic chemical use, and developing “error-proof” management systems. Other experts emphasize a need for transparency and traceability to cattle ranches to address possible deforestation.

“The overall system should be monitored and audited as per local and international environmental regulations,” Paul wrote in an email. And that “is not a one-time [task]. The industry should work endlessly to protect the environment.”

Leading by example

The Scottish Leather Group is one company aiming to clean up leather’s environmental image through its own example. The firm claims that its products have the lowest carbon footprint of any leather manufactured anywhere, achieved through a suite of circular production solutions developed over recent decades.

The company started with a desire to minimize waste, and to utilize all of the leather it sourced in a variety of final products, says Warren Bowden, head of innovation and sustainability at the company. “Historically,” he says leather production has used “a linear approach … with roughly 90% of the hide weight never end[ing] up as leather.”

The Scottish Leather Group aims at using everything — not only making leather, but also recovering unused raw material to be sold as biofuels or other products, rather than sending it as waste to a landfill. Anything that’s not “recoverable saleable commodities” the firm uses as fuel in its leather factory, displacing fossil fuels, says Bowden. “That’s a massive piece in terms of reducing the carbon intensity of the product.”

The company has also engineered an innovative waste recovery system, taking back leather seats it has sold to airlines, for example, then shredding and burning them to “create the energy for the next set of [manufactured] leather seats,” he explains. Though this energy recovery scheme is still relatively small scale, Bowden says the company ultimately plans to recover used leather to be refashioned into other materials. “All that leather must go somewhere. And for me, there’s a massive opportunity to recover it, take it back and do something more interesting with it. That’s where … the future is.”

Such solutions have so far enabled the company to slash its landfilled waste by nearly 80%. The goal, notes Bowden, is to reduce that to zero by 2025. Similarly, water use in manufacturing is down thanks to a treatment system that cycles used water back into production. That has slashed the need for water drawn from a private Scottish loch. “We found that by treating [water] to the point you could recycle it, you could significantly reduce the amount you’re actually drawing,” he says.

Leather alternatives and the trouble with plastics

While some long-established leather companies aim to reduce impacts and go circular, other firms and researchers are innovating to produce alternative fashion materials.

Jinali Mody, founder of the startup Banofi, for example, sees a sustainable alternative to leather in the millions of tons of banana waste produced in India each year. Her company purchases banana waste directly from smallholder farmers and fashions it into leather-like materials.

“We source our waste directly from the farmers and we provide them with additional income for their waste,” she says. “These farmers typically would dump [the banana waste] or burn it.”

Currently, Banofi’s products consist of around 60% banana crop waste, 20% other “natural components,” and around 20% synthetic additives, including recycled plastics.

“We’re extending the life of waste,” Mody says, noting that at the laboratory scale, the firm’s product has proven to be 100% circular because after its initial use, it can be reworked into harder materials, such as book covers.

According to Mody, her firm’s banana leather outperforms both bovine and “vegan” leathers derived entirely from plastics such as PVC. In addition, Banofi requires vastly less water, and achieves roughly a 90% carbon reduction compared to animal and plastic-derived leather, while emitting no toxic waste during production, according to the company.

Banofi is just one innovative example of newly launched companies manufacturing alternative leather products in an expanding market predicted to be worth $45 billion by 2025. Apples, pineapples, cacti, tea waste, fungi, and lab-grown leather products are all in the works. And even as a range of “biobased” products are produced, a strong market for “vegan” or alternative leather already exists.

But many of these new products suffer from a serious drawback: their heavy reliance on plastics to increase durability.

Adrian Lopez Velarde, director and co-founder of Desserto, a Mexico-based firm that produces a leather alternative sourced from cacti, says that even though its products are not “100% plastic-free,” they outperform traditional leather and polyurethane products from a sustainability perspective. Looking across the entire leather life cycle, he states that circular farming solutions reduce water use and cut out harmful chemicals.

Achieving completely plastic-free biobased products is an ambition of alternative manufacturers, but remains a technical challenge yet to be overcome.

“If you have a 100% plant-based alternative to leather, it’s not going to last,” Velarde explains. As a result, some synthetic additives are necessary to “not only make a material perform, but also make it desirable for designers.”

“The vegan market right now for leather is dominated by plastics. That is true for both purely plastic material, but also plastics that have been mixed in with biomass,” explains Griffin Christiansen, a regenerative strategist at Natural Fiber Welding. His company hopes to displace plastics entirely by basing its source material on ingredients such as rubber and cotton, and by implementing circular solutions throughout production.

“I think the only true alternatives are products that will break down in nature or are not using plastic,” Christiansen says.

The future of leather

Steeped in history, the leather industry is changing fast, say analysts. But it’s future is advancing in several directions at once, as some manufacturers bet that synthetic materials or plastic-free biobased materials will come to the fore, while others see big opportunities for a cleaner, nonpolluting and toxic-free hide-based leather industry.

In the end, all this diversity may triumph. “I do think we need many materials, we don’t only need leather,” to achieve sustainability says WWF’s Bellese. “What doesn’t make sense to me is to discuss not using leather while we are [still] raising cattle.”

In his view, innovating with new materials is necessary. At the same time, the traditional leather industry needs to focus on raising cattle responsibly, replacing and reducing chemical use, limiting water utilization, introducing more renewables, and ensuring effective wastewater treatment. “There are solutions [already available] for all those things,” he adds.

Some experts are cautious about exclusively backing leather alternatives because in the attempt to avoid traditional leather production environmental pitfalls, makers may exacerbate other problems. “I have a positive opinion about these [alternative leather] developments, as long as they are not fossil-fuel based,” says researcher Mammadova. “Material origin is important, but so are the processes and the chemicals we use [in producing leather], and thinking about end of life is essential if we’re aiming for circularity.”

Banner image: A woman is laying leather out to dry in Bangladesh. Image by United Nations/UN Women/Rashid Probal via Flickr (CC BY-NC-ND 2.0).

Citations:

Moktadir, M. A., Dwivedi, A., Khan, N. S., Paul, S. K., Khan, S. A., Ahmed, S., & Sultana, R. (2021). Analysis of risk factors in sustainable supply chain management in an emerging economy of leather industry. Journal of Cleaner Production, 283, 124641. doi:10.1016/j.jclepro.2020.124641

Moktadir, M. A., Ahmadi, H. B., Sultana, R., Liou, J. J., & Rezaei, J. (2020). Circular economy practices in the leather industry: A practical step towards sustainable development. Journal of Cleaner Production, 251, 119737. doi:10.1016/j.jclepro.2019.119737

Oliveira, M., Zucaro, A., Passaro, R., & Ulgiati, S. (2023). Life cycle assessment of leather treatment at various scales: Comparison between chrome and vegetable processes. The International Journal of Life Cycle Assessment, 29(2), 153-173. doi:10.1007/s11367-023-02232-3

Mammadova, A., Behagel, J., & Masiero, M. (2020). Making deforestation risk visible. Discourses on bovine leather supply chain in Brazil. Geoforum, 112, 85-95. doi:10.1016/j.geoforum.2020.03.008

Mammadova, A., Behagel, J., Masiero, M., & Pettenella, D. (2022). Deforestation as a systemic risk: The case of Brazilian bovine leather. Forests, 13(2), 233. doi:10.3390/f13020233

Wrzesińska-Jędrusiak, E., Czarnecki, M., Kazimierski, P., Bandrów, P., & Szufa, S. (2023). The circular economy in the management of waste from leather processing. Energies, 16(1), 564. doi:10.3390/en16010564

Gargano, M., Bacardit, A., Sannia, G., & Lettera, V. (2023). From leather wastes back to leather manufacturing: The development of new bio-based finishing systems. Coatings, 13(4), 775. doi:10.3390/coatings13040775

Islam, M. R., Islam, M. S., Akter, J., & Sultana, T. (2023). The studies of environmental load and consequences of leather industrial effluents in Bangladesh. Journal of Environmental Impact and Management Policy, 3(1), 1-14. doi:10.55529/jeimp.31.1.14

Pringle, T., Barwood, M., & Rahimifard, S. (2016). The challenges in achieving a circular economy within leather recycling. Procedia CIRP, 48, 544-549. doi:10.1016/j.procir.2016.04.112

Fernandez-Zamudio, M., Barco, H., & Schneider, F. (2020). Direct measurement of mass and economic harvest and post-harvest losses in Spanish persimmon primary production. Agriculture, 10(12), 581. doi:10.3390/agriculture10120581