FASH 666 | grace lundquist

Leather: Does it stand the test of time?

Grace Lundquist

If we were to take one look into our closet, our shoe rack, or any contemporary clothing store, we'd likely find at least one item made of leather, or it's faux alternatives. It’s a timeless material that has been traced back to thousands of years ago where the animal byproduct began being used as such; to make clothing, footwear, and tents. In modern day, we see leather used beyond apparel- in our cars, our furniture, sports equipment, etc. As consumers, its seemingly unavoidable. Leather’s durability and luxuriousness make it attractive, as its products often last decades. It’s also functional, even vital, for particular applications. There is a recognized need and demand for this material. Yet, as the demand and production of this material has increased, due to globalization and growth in consumerism, the environmental impact and concerns of it has, too.

Traceability has become an increasingly imperative word in the apparel industry over the course of the past decade. As consumers, we've become more aware of the ethics, or lack thereof, in the making and selling of our clothes. Globalization has impacted how accessible information regarding our clothing is- the supply chain is spread across the world and operates faster than it ever has, in greater volumes than it ever has. For apparel companies and brands, their integrity is on the line with the demand of social responsibility and sustainability improvements.

When it comes to leather, the production and sourcing process has been clouded as the industry expands worldwide. As we know, leather is everywhere; it endlessly exists in our products. So, it begs us to question how ethical and sustainable the esteemed material really is. Does it stand the test of time?

The Basics

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Leather making and usage dates to thousands of years ago across all corners of the world. The process itself is an ancient art form that began quite simply: with no more than the drying of skins in the sun, pounding of excess animal fats, and finally its preservation through salt and smoking techniques (Britannica, 2020). Archaeologists have even found indications of tanning methods used by Neanderthals roughly 100,000 years ago after discovering organic scraps left on tools containing high levels of tannin from oak (Black, R. 2021). In the Americas, indigenous peoples relied on leather for several uses, both cultural wear and practicality. Anorak jackets, originally worn by people in the Artic, were constructed using available animal skins like deer and seal to achieve greater insulation and protection from harsh weather (Campagna, 2021). The use of leather continued to spread and, as with the manufacturing of any good, the Industrial Revolution in the nineteenth century began to change the way and the rate that leather was being produced.

The modernized leather manufacturing process can be divided into 6 key stages from livestock farming to final finishings.

It begins with 1) livestock farming which is typically cattle and other animals reared exclusively for meat and/or dairy consumption and are the source of 99% of the world’s leather (exotic animal skins are an entirely different conversation regarding farming and ethics). Following this, 2) raw material is collected during the slaughtering process in which skin and hides are separated from the meat and remaining parts of carcass.

Moving on to preparation stages, the skins arrive at the 3) beamhouse where they undergo extensive preservation and prepping treatments. This stage requires several processes to be completed to ensure materials are prepared for tanning.

Soaking/Curing: Rawhides are soaked in water in order to rid of any dirt or dust. Dried skins use a similar process, curing, where chemicals are added to the water in order to restore water content and allow them to return to their softness.
Liming: Hides are then soaked again, but this time in liming drums containing lime and sulphur. This step removes or loosens hair from the hides, as well as loosens skin fibers for easier tanning.
Fleshing: The removal of excess flesh on hides.
Splitting: The division of skin layers, resulting in a 'top layer' (smooth grain) and 'bottom layer' (suede/split grain).
Pickling: A chemical process to increase acidity of the hides and preparation for tanning.

With hides prepped, they then move on to the 4) tanning process. During this stage, tannins, chemical compounds used to preserve collagen fibers, are absorbed to transform the hides into what we know as 'leather.' Today, this is typically performed using chromium based tanning agents; likely alkaline sulfate (Chrome III) and a combination of other acids and chemicals.

Chrome tanning is preferred in the industry as its quick- it can be completed in just a day due to its chemical compounds- and it produces lighter-weight hides compared to other tanning agents, making it popular in clothing and accessories. However, vegetable tannins have recently been growing in demand.

Vegetable tanned leather is often viewed as the more environmentally preferred option for consumers and manufacturers as its easier to breakdown after use due to its organic composition. Some vegetable tanning substances include tree bark, leaves, and root. However, many still avoid this process as its extremely time consuming and therefore comes at a higher price.

Post tannery, hides are just about ready for export. In the 5) wet-end, hides go through dyeing, fatliqouring (regressing), and retanning to aide the hide in improving desired properties. Hides are then dried and softened before reaching finishings.

6) Finishings for leather hides consists or various treatments depending on the intended function. These include protective coatings, glossing, embossings, and pigmentation.

Ultimately, these hides and skins used for leather are a direct byproduct of the meat industry. During the slaughtering process, skin and hides that are not reserved for leather making, are discarded and often landfilled. For this reason, some may view leather as a regenerative material. Others, who may be familiar with the process, say that couldn't be further from reality.

Leather vs. The Environment

The largest concern for the leather industry is the direct impact it has on the environment and both the people making and consuming these goods. The manufacturing process is hazardous and emits pollutants throughout all stages, especially with the direct link to the cattle industry, the single largest driver for the deforestation of the Amazon and other rainforests globally. Many consumers are opting out of cattle linked products as that industry alone, in the Amazon, accounts for about 2% of annual global CO2 emissions (World Resources Institute, 2016.)

The tanning process also remains a primary concern due to the volumes of waste generated during this stage. The waste exists in two forms: solid waste and wastewater. With the absence of proper management of the waste, toxic chemicals are finding their way into parts of our environment in which they don't belong.

Deforestation

Consumers are finding it difficult to justify supporting the leather industry as its connected to the very real harm caused by excessive cattle farming that generates alarming forest loss. And while leather isn't directly fueling the farming, it is lucrative to the countries where farming takes place. In Brazil, its estimated about $1.1 billion in revenue was generated from the leather industry alone in 2020 (Stand Research Group, 2022.)

This is where the concern for traceable and socially responsible sourcing comes in. The complexity of global supply chains makes it difficult to determine where all parts of a product are coming from and with leather, consumers have a valid concern with their products being connected to deforestation. Stand Research Group found that over 100 brands are connected to the largest cattle producer in Brazil, JBS, suggesting that many of our favorite brands are at risk for driving deforestation further. These range from fast fashion brands to luxury fashion houses. And while some companies do have policies in place to not source leather from Brazil, like VF Corp, public information and acknowledgment on the effectiveness of their suppliers to uphold these policies are unclear.

Solid Waste

As skins and hides are processed throughout the stages of the leather making process, scraps are discarded and landfilled. This is a combination of skin trimmings, shavings, fleshings, hair, and chemically treated material. Much of this waste contains proteinaceous fibers of keratin and collagen, and if not properly discarded or regenerated, can and will cause substaintial environmental harm, especially at the volumes of which the supply chain demands. Environmental damage includes the release of large levels of methane and carbon dioxide.

Wastewater

Although vegetable tannins have become increasingly popular over recent years, chromium-based leather tanning continues to be the most common method of leather tanning. It’s estimated that roughly 90% of leather that is produced uses chromium in its process (Sundar, Rao, & Muralidharan, 2002), leading to various environmental and health concerns. In tanneries, wastewater is generated through the harsh chemicals penetrating the hides. Ideally the hides would absorb all chemicals during treatment, but that is not the case. The excess water used for tanning, usually 30-40%, is left with toxic and carcinogenic chemicals that are known to be associated with respiratory cancer (Sharabaty, R., & Sarsour, S). And, too frequently, this water is improperly disposed of and released into sewer systems, ground water, and soil.

In Palestine, home to many tanneries who contribute greatly to the nation’s economy, wastewater containing high levels of chromium are drained in the public sewers leaving residents at risk (Sarabaty, R., & Sarsour, S).

In even closer and higher concentrated proximity to these hazardous chemicals are the tannery workers themselves. Not far from Palestine, in India, a study was conducted on tannery workers to evaluate how exposure to tanning chemicals, such as chromium, effects human health. It found that morbidity more than doubled (40.1%) in tanners than the control group (19.6%)- industry workers who were never exposed to tanning chemicals (Rastogi, S. K., Pandey, A., & Tripathi, S.). Tanners who were exposed experienced chronic bronchitis, occupational asthma, allergic bronchitis, sinusitis, and pulmonary tuberculosis.

Leather and The Environment

I think it's safe to say that there's valid concerns for the leather industry and it's environmental implications. This isn't news and for years inter-sectionalists of the fashion industry and sustainability have been advocating for improvements. Efforts for change come in various forms but the key issues being reiterated by consumers and brands are environmental concerns (i.e. waste management) and ethical practices.

Waste Management & By-Products of Leather Manufacturing

Waste is heavily generated throughout the leather manufacturing process, as we know. But, just as leather is the byproduct of the meat/dairy industry, many other industries have their stakes in the leather industry, as well. Taking advantage of these other by-products is one way the industry can manage the solid waste issue at hand.

Through the extraction of protein fibers found in the solid waste, like collagen and keratin, an extensive amount of byproducts are generated for commercial use. These applications include: fire extinguishers, wound dressings, prostheses, drug capsules, sausage casings, meat substitutes, biodiesel, pet food snacks, animal feed, fertilizers, ceramics, detergents, and cosmetics (Sundar, J., Gnanamani, A., Muralidharan, C., Chandrababu, N. K., & Mandal, A. B. 2011). The possible applications are all dependent on how the fibers are extracted and at what stage during the manufacturuing process this takes place.

Other waste management efforts occur when the hides and skins have already reached the landfill. Leftover leather from the abattoir and tannery stages are typically 'composted', though depending on what chemicals they've been exposed to, they don't easily break down and they actually release those toxic elements into the environment. Instead, there have been efforts to incorporate vermicomposting which is a process that uses earthworms to convert the organic waste into a desired nutrient-rich product, thus termed 'vermicompost' (Patel, K., Munir, D., & Santos, R. M, 2022). The earthworms actually have the capability to reduce chromium content in the leather waste making it a natural waste management tool. Due to the worms' ability to stabilize the organic content, it generates a by-product of a waste-derived substitute for agriculture inputs (manure).

Ethical Tanneries

Others in the industry have focused their energy directly into managing the ethics of the tanneries. Green Hides an American based company who is tied to a local Italian tannery located in northern Italy that is dedicated to ensuring leather is sourced and produced ethically. Living up to their name, Green Hides exclusively uses solar power and goes to great lengths to incorporate recycled materials into their production process/facilities. Their mission is to use closed loop, low emission tanning practices while complying and EU environmental regulations. A key focus is to eliminate usage of conflict minerals which is why they maintain 3TG conflict-free and ensure their leather is never sourced from deforestation regions.

While being but one company, Green Hides is a leading example of how intentional business practices can create a domino affect in the supply chain by setting expectations.

Alternatives to Leather?

Mirum

Mirum is one of a kind. The product, from Natural Fiber Welding, was initially launched in 2019 and in just four years ago has already made massive strides. It has marketed itself as the first biodegradable, plastic-free leather alternative in the market. Its contains zero synthetics but has comparative performance to genuine leather. There really is nothing else like it.

For being such an innovative product, the process is actually quite simple.

A key part of the process is the first stage: 1) sourcing the materials. The ingredients that make Mirum what it is varies greatly on what type of 'leather' is the desired outcome, though they are all bio-based. Examples of these include agri-waste (cork, coconut, rice hulls), natural rubber (sap from hevea brasiliensis tree), and earth elements (salt, silt, clay, & minerals).

When all materials are sourced, they are 2) mixed and 'sheeted' at NFW's home factory in Peoria, IL. This step is simply blending all necessary materials together and dispersing them in a flat spread to prepare for the final step.

To finish, 3) material is pressed onto a fabric backing for stability. Due to the chemical properties of the natural ingredients, NFW has developed the backing process to be free of any adhesives which is typically toxic on other leather alternatives. This step also includes embossing, if needed, to give MIRUM a leather-like look.

At the end of Mirum's lifecycle, there are a couple of options customers can make as it is both 100% recyclable and 100% circular in nature. Customers can return the material back to NFW and it can be remade into a new 'leather' sheet, or, due to its 100% bio-based composition, it can be return to Earth through composting and zero harm done to the planet.

Traditional Leather Making Production Process (1).png

With many consumers opting out of traditional leather, whether that be due to ethical motivation in terms of animal byproducts or environmental concerns, the leather alternatives market has massively developed over the last decade. These materials are often referred to as ‘vegan leather’, ‘faux leather’, or ‘synthetic leather’, but it wasn’t until just this last year in 2022 when Textile Exchange formally adopted an official definition for ‘leather’ as, “a hide or skin with its original fibrous structure more or less intact and tanned so it does not rot.” Many, both stakeholders and oppositions to the leather industry, applaud this effort for transparency and labeling (LCHA, 2022). With ‘leather’ being detached from non-leather materials, consumers, designers, and manufacturers alike are able to consciously choose materials for their standards.

PU & PVC

Within the leather alternatives market there are what seems like endless options. The most common are PU and PVC. PU, or polyurethane, which is composed of 100% synthetic thermoplastic polymer. Many consumers opt for clothing and accessories made from this material as its generally affordable and widely available. As it is synthetic, this is also a popular option among consumers looking to avoid animal byproducts. Yet, PU is not made to last like its originator, and it is not the most environmentally friendly option on the market: it generates fossil fuels during production and due to its synthetic properties, it doesn’t decompose.

For consumers looking for a 'greener' way to incorporate this material into their wardrobe, many brands have began offering PU composed of recycled materials such as plastic ocean waste or discarded plastic water bottles which are ground up and melted to form a 'leather-like' material.

Similarly, PVC, or polyvinyl chloride, which is often referred to as 'vinyl', is a plastic alternative to traditional leather. PVC is a flexible, resin material that consists of a blend of chemicals, fillers, and additives to achieve the leather-like look. It, too, is a concern as this material isn't a closed loop product- it doesn't biodegrade and the harsh chemicals and fossil fuel generation during manufacturing poses a threat environmentally.

Plant Based Alternatives

Pineapple 'Leather' - Piñatex

Developed by Dr Carmen Hijosa and her observation of unethical leather manufacturing processes, Piñatex is an alternative derived from fibers extracted from pineapple leaves. The process begins when scraped leaves left over after harvesting, which are typically burned or left behind, are collected for extraction. Then fibers then go through a washing and drying process and blended with polylactic acid (PLA - a cornstarch based plastic) before moving to the finishing stages. To complete, the Piñatex is finished with a synthetic PU coating to secure performance capabilities.

Piñatex is an innovative by-product process in which benefits small, developing farm communities while minimizing the carbon footprint of the 'leather' process. There is a clear cultivation of community and the environment. However, Piñatex has not yet reached a fully closed loop system where its products are 100% biodegradable, as 80% of the material is plant based and 20% remains synthetic.

Mushroom 'Leather' - Mylo

This plant based alternative is derived from mycelium, the root structure substance of mushrooms. By now, multiple bio-tech manufacturing companies have refined their own processes to create this leather-like material. Bolt Threads, of Berkley, CA, have developed a process through a vertical farming system. In their 100% renewable energy powered facility, mycelium cells are grown and harvested alongside organic material until they are dense enough to be processed into 'foam-like mats'. This whole process is quick- in a matter of weeks or even just days before- its ready for finishing. During the final stage, Mylo is tanned in partnership with a Leather Working Group (LWG) gold rated tannery. It is unclear what specific tanning processes take place, though gold-rated is the highest in terms of environmental performance.

While Mylo is petroleum free, at this point it fails to be plastic free in refusal to compromise quality and performance most similar to genuine leather or PU/PVC alternatives, though there are continuous efforts to minimize synthetic ingredients. Additionally, there are no current options for recycling or repurposing this material.

Mango 'Leather'

A relatively fresh development in the plant based category is this leather alternative derived of discarded mangoes. Fruitleather Rotterdam is a producer of this material based in the Netherlands giving new life to this fruit that is left over from farms as they don't meet standards. After breaking down the flesh of the fruit(s), the manufacturing process requires non-specified natural additives in order to create a leather-like texture. Following this, the paste-like substance is placed on baking trays to dry and prepare for finishings. The sheets are then covered in, again non-specified, protective coating before being pressed onto their backings, and finally embossed.

The process offers lesser fossil fuel emissions while combatting food waste generated from farming and remaining free from animal products or byproducts. The material as yet to reach fully bio-based status and it remains unclear water recycling is a possibility at the end of the product's lifecycle.

Cork 'Leather'

Products derived from cork oaks are nothing new. The trees are native to the Mediterranean and have been used for consumable products for (at least) 5,000 years (Mahi Leather, 2021). Even traditional leather making using the vegetable tanning process opts to incorporate cork by using it as the tanning agent. The 'harvesting' of cork is completely harmless as it just requires the removable off the bark from tree trunks, and it's even said this removal process is beneficial to the trees' lives. After this, the bark is dried for roughly 6 months before it moves to the final processing stage. Here, it will be boiled, flattened, and backed with adhesive.

The biodegradability of the cork alternative is dependent on the finishing coatings which can vary depending on the performance expectations. That being said, cork performance is still far from what genuine leather is able to offer and the product isn't built to last. Yet it remains a top performer as far as leather alternatives go.

Answer: Yes and No

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The future of leather is widely unknown. Just as many issues involving ethics, it remains in a very grey area with differing opinions and ideas on tackling the issues that have unfolded over recent years. And as a product within the global supply chain, these issues become severely complex without a simple answer or solution.

From my findings, I'm inclined to believe there is a definite purpose and space for genuine leather to exist within our products. The durability and performance of leather is, so far, unmatched. Ethically and morally, I share the concerns with many industry professionals and consumers like myself. Just as there is a need for this material, there is a need, and a shown desire, for innovative practices to protect the sanctity of the planet and its inhabiters. There are pros and cons, as I've outlined, and there have been, and will continue to be, efforts to slowly eliminate the cons to make space and to justify a byproduct from other over-produced and over-consumed industries.

However, numbers show there continues to be a growing interest and commitment amongst consumers to opt for products that align with their belief systems. WGSN reports for A/W 2023/2024 that genuine leather usage and desirability will decline amongst consumers as sustainability concerns rise. With the growth of consumers' desire to purchase 'purpose-driven materials,' so does the growth of leather alternatives (Palmer, H & Cortesi, E, 2022).

Mirum, a leather alternative discussed previously, continues to stand out as the highest performer in terms of leather-like quality with zero usage of synthetics. The science behind this material is a remarkable example of circular product life cycles and the possibility and existence of fully regenerative materials in the apparel/accessories industry. Mirum has precisely found a way to eliminate the 'cons.'

As consumers, we have stakes in the apparel industry which can feel heavy with the overwhelming amount of information we now consume. We can easily feel a sense of guilt after learning about the harsh realities and complexities of the global supply chain(s). Sometimes there is no, "Yes," or, "No," to the questions we are confronted with, but we can continue to exist in the grey and learn as we go.

Refrences

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Stand Research Group. (2022, November 21). Nowhere to hide: How the fashion industry is linked to Amazon Rainforest Destruction. Stand.earth. Retrieved March 23, 2023, from https://stand.earth/resources/nowhere-to-hide-how-the-fashion-industry-is-linked-to-amazon-rainforest-destruction/

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