IntroductionThis report addresses the current sustainability issues of leather production in the fashion industry. The main issues being the “toxic chemicals used in tanning and production” (Piñatex, 2018). In order to do this, the different stages involved in processing leather, from the sourcing of the hide to the end finishing processes applied, need to be considered. Research has been carried out into new developments that claim to be “a new kind of leather” (Mycoworks, 2018) and, at first glance, appear to be more sustainable. Alternative developments that have been researched into further include different types of fruit and mushroom materials, produced by companies such as Piñatex, Happy Genie and Bolt Threads. When comparing synthetic alternatives, such as PVC, and alternative “leather” materials, the qualities of genuine leather have to be considered. It is important to understand why leather has been so successful within the fashion market and why some manufacturers may be unwilling to adapt to these new developments.Leather and its QualitiesLeather has had a huge impact on many different areas of industry over the years such as furniture, musical instruments, book binding, transport and fashion, to name a few (Pringle, 2017). Throughout the twentieth century, leather has been a part of many different fashion trends and eras; from punks to world wars. It has been described as a ‘second skin’ that stays with someone for life and is then passed down to future generations (Indie Bio, 2016). Surely a material as iconic as this can’t ever be replaced?Leather has numerous appealing qualities and is an incredibly versatile material. Many leather workers and artists believe that leather has much more to offer than has currently been explored (Meilach, 1972). Some have dedicated their careers to working solely with leather due to its unique and fascinating qualities, specifically its “flexibility and variety of textures” (Meilach, 1972). As leather is a natural material, every skin creates a varying surface texture and as a result responds differently to cutting and shaping methods. One notable quality is that leather reacts differently when its wet to when its dry. Leather can be made incredibly soft or almost completely solid depending on which method of tanning has been used. Under the right conditions it can “retain a given form almost indefinitely” (Meilach, 1972). Many factors influence the characteristics of a hide including age, breed, gender and diet (Quilleriet, 2003).In terms of comparability to other fabrics, leather has great tensile strength which makes it resistant to temperature changes that would ordinarily weaken textile materials. It also boasts a porous structure, making it suitable for many types of clothing to be worn in different climates. Arguably the most impressive quality of leather is its texture, which can be improved through polishing and treatments applied. Normally leather has a lustrous surface and it can be dyed to produce rich colours that would be much harder to reproduce in other materials (Meilach, 1972).Why is leather production unsustainable?We can no longer keep up with demands for the industry, making production unsustainable; Resources are being consumed much faster than they can be replaced. The tanning process requires approximately 250 chemicals in order to stop the hide from decomposing, all of which are damaging to the environment and the people in it (Piñatex, 2018). The processing of leather demands considerable amounts of energy and water, as well as a large number of hazardous chemicals. When responsibly produced, leather can be an incredibly sustainable material (Stahl.com, 2018), the problem being that most practices that are currently used are not responsible or environmentally friendly in any way.As a natural material, skin has to be treated with a preservative to stop it from decomposing, this process of converting a raw hide into leather is known as tanning (Ashoka Paris, 2018). This stage stabilises the protein fibres to stop biodegradation (PETA, 2018). This often involves the use of Chromium which is known to be a carcinogen (Ashoka Paris, 2018) and considered hazardous by the EPA (PETA, 2018). This is particularly dangerous for developing countries who don’t have the right tools to manage this. A lot of tanned leather comes from India and China whose lack of regulation means that contaminated waste and chemicals are left in the soil and groundwater, polluting water for nearby communities (Ashoka Paris, 2018). Those who work in or close to tanneries are exposed to these waste chemicals and develop illness because of it. It’s thought that in Bangladesh “90% of workers in this industry will never exceed 50 years old” (Ashoka Paris, 2018).There are a few different methods of tanning leather – the most widely used being chrome and vegetable tanning. Most leather today is chrome tanned because it has a relatively quick turnaround and produces a leather with qualities suitable for a wide range of commercial products (Meilach, 1972). Vegetable tanning is sometimes used afterwards to produce extra qualities such as water-resistance and a lightweight quality. Leather is hard to dye consistently due to the unique nature of the material. Some fibre variations that affect colouring cannot be removed by any process, but it is often these inconsistent qualities that people appreciate (Meilach, 1972).Hides also have to be dried in order to be turned into leather. This involves conditions of low temperatures, a well-ventilated space and no direct sunlight that could make the hide stiff. If left untreated, bacteria would deteriorate the material. Once dried, oils must be added to restore the material’s flexibility. This preservation stage must be done almost immediately after removal from the animal, therefore is done near to where the animal is slaughtered. This protects the hides until they can reach the tannery. Other stages of preservation include hair removal, defleshing and machine processing (Meilach, 1972). Only small hides are dried in Europe (Quilleriet, 2003) meaning that larger hides and different kinds of leather must be imported, adding to leather’s overall carbon footprint. An ideal environmental solution would be for the material to be produced in the country that it will be used in. Although, this has all sorts of other issues to consider relating to trade and economy.The largest environmental impact of leather production is thought to be among less developed areas of the world. The process which hides undergo in order to be cleaned to be turned into leather uses 650 million kilos of CO2. It’s estimated that in one year more than a billion animals will be slaughtered for their skins to be turned into leather (PETA, 2018). Globally, the meat and leather industry CO2 emissions have increased by half in the last 20 years. Other dangerous chemicals used in this industry include cyanide-based dyes and formaldehyde. 16,000 litres of water are required to produce just 1 kilo of leather (Fruitleather Rotterdam, 2018). Before leather can be produced, animals have to be reared which involves a lot of resources in itself (PETA, 2018).Leather is a by-product of the meat industry and many share the view that they ‘love the qualities of leather, but it’s a resource-intensive product that is tied to the livestock industry’ (MycoWorks, 2018). Leather’s lifecycle is unsustainable and waste products are produced at nearly every stage. These waste products are difficult to dispose of; Recycling options for leather aren’t effective enough and often create leather that is of a much lesser quality than the original (Pringle, 2017).Other environmental issues are emerging from over-farming. It’s estimated that in the amazon rainforest, livestock are accountable for 80% of deforestation – this is 14% of deforestation throughout the whole world (Ashoka Paris, 2018). Deforestation on this level causes habitat loss for millions of species which has a knock-on effect around the world. It also reduces the World’s tree canopy, fuelling climate change (PETA, 2018). Another large issue is eutrophication – This is when water contains an extreme amount of nutrients, usually from run-off waste, which causes plant life to overgrow. Excessive plants in water systems means that oxygen levels deplete, making it difficult for animals in this ecosystem to survive (PETA, 2018). Food and Agriculture Organisation of the United Nations (FAO) have discovered that the meat and leather industry “is responsible for 18% of greenhouse gases” which is more than the entire transport industry altogether (Ashoka Paris, 2018).What are the issues with synthetic alternatives to leather?Producing synthetic materials has an environmental impact 20 times less than producing approximately 1kg of leather (Ashoka Paris, 2018). PETA suggests that PU leather has an environmental impact three times lower than that of leather (PETA, 2018). When treated and preserved, leather can survive better than many alternative materials (Stahl.com, 2018), however, this needs to be balanced with the initial environmental cost of production.Synthetic materials are also required to receive chemical and finishing processing for manufacture, therefore both aren’t able to biodegrade quickly (BLC Leather Sustainability, 2018). During the time it takes for PVC to biodegrade, the material releases toxic chemicals into the Earth (Piñatex, 2018). Leather has a greater capability to biodegrade as it’s from a natural resource but the way in which it’s produced makes it unsustainable. According to Greenpeace, PVC is the “single most environmentally damaging type of plastic” (BLC Leather Sustainability, 2018).There is yet to be developed a synthetic material that is able to “usurp leather’s prominent place” (Quilleriet, 2003). Leather is a material that everyone has grown to love over many years, replacement of this “chameleon-like material” within industry will be incredibly challenging (Quilleriet, 2003).What new developments exist and do these have the potential to replace leather?There are a number of companies who have already developed alternative materials imitating some of leather’s qualities. These are currently trying to immigrate into the market to allow for cheaper production costs – without the need for the material in the market there is no point in companies producing these alternative materials. Almost all these alternative materials stem from a natural resource, often from waste biomass that would otherwise not be used.One such material is a leather-like material made from part of a mushroom organism known as mycelium. A mushroom as we know it is actually the reproductive structure of mycelium (Stamets, 2005). Many of us don’t realise the extent to which mycelium is vital to ecosystems. It’s been thought that plants and trees wouldn’t be able to reach maturity without their symbiotic relationship with mycelium. They are said to be “the grand recyclers of our planet” (Stamets, 2005). Mycelium is a fungal network of membranes underneath the ground that respond to the ecosystem growing above. They can react and respond to the environment around them, unlocking nutrients stored in plants and helping to build up soil. Some who study mycelium believe that they are “Earth’s natural internet”, sending constant chemical data through their network and altering its behaviour and growth as a result (Stone, 2018). However, a lot of scientists who study mycelium still don’t realise its full potential for avoiding our environmental destruction (Stamets, 2005).So, what’s this got to do with producing an alternative material to leather? Well, Stamets believes that we can train mycelium to decompose waste. A field expedition to the Ecuadorian Amazon in 2011 discovered that a certain type of rainforest fungus had evolved to breakdown polyurethane, which is a plastic polymer found in many common household items. It was suggested that by cultivating this fungus for use in our landfills we could potentially breakdown plastic much faster (Stone, 2018).When the environmental conditions are right in terms of temperature, light, moisture, as you would expect with any growing organism, mushroom spores germinate into threads of cells which in turn produce a matted material that builds with the more nutrients you supply it with, often in the form of waste biomass. When using the correct substrate and conditions for growth its thought that mycelium can make any shape or density (Stone, 2018). Mycelium can be given a head start with this decomposition process by supplying it with hydrogen peroxide which is readily available, inexpensive and fairly harmless, especially in comparison to the numerous chemicals used in leather production (Stamets, 2005).One of the companies producing this mushroom material is Mycoworks, who claim to have created a material that is “sustainable”, “versatile” and “performs like leather” (Stone, 2018). They use various plant waste to create this material such as pistachio shells, corn husks and sawdust which otherwise serve little purpose to us (Stone, 2018). Mushrooms grow at an incredible rate, much faster than leather can be produced – the size of a cowhide can be grown in just two weeks. It can be grown to any size or shape (Indie Bio, 2016) allowing the manufacturer to adapt the production process. Ever-changing consumer habits will most likely require manufacturing systems to be much more adaptable in the future. For this to happen resources will need to be recycled through a close-loop system (Pringle, 2017).The question isn’t how fast the material grows, its whether we can actually keep up with the organism’s growth rate (SciFri, 2016). Mycoworks claim to be able to create patterns in the material to simulate leather and create different colours that aren’t possible with cow hides. They also state that they can grow different qualities into the material depending on the end purpose. From current tests they have found that their material is as strong as deer leather, meaning it’s stronger than sheep and synthetic leathers. It is naturally water-wicking and antibiotic without the addition of chemicals (Indie Bio, 2016). Another interesting point worth mentioning is that they believe this method of production has the potential to grow fasteners into the actual material, making the need for glue unnecessary, and therefore reducing the environmental impact of the material further. As this material is organic, it is biodegradable and is produced using a closed-loop process which requires low water and energy (Indie Bio, 2016).Another company also producing a new material from mushrooms is Bolt Threads, known widely for creating “Microsilk” which mimicked spider silk. “Mylo” is produced in a similar way to MycoWorks. Their material, Mylo, has already been seen on the market in Stella McCartney’s handbag which was on display at the V&A in London last year (Anzilotti, 2018). Whilst Mycoworks are still developing the perfect sustainable solution to the issue at hand, Bolt Threads seem to be more focused on getting the material on to the market as fast as possible, regardless of whether having to separate the material from its handbag parts at the end of use makes the material less sustainable for its intended purpose in the fashion industry.A German company, ZVNDER, is also creating a mushroom material out of tinder fungus which is found on weak or dead trees for a number of years. They produce this leather for the purpose of making products such as wallets and watch straps. They claim that this tinder fungus “leather” is “only visually similar to animal leather” but contains the qualities that they need to produce an effective alternative for their company’s intended purpose; high-absorption, lightweight, antibacterial. The material’s unique qualities are kept in mind and adapted to meet the product’s requirements. An example of this would be their shoe insoles which have successfully helped to prevent athletes’ foot due to the antibacterial nature of the material (Preuss, 2018). Perhaps this is where other companies are failing; by trying to recreate leather in its entirety rather than creating a material fit for purpose.They source their tinder fungus from Romania in a dense forest region where the fungus can be found growing. This is somewhat more sustainable than, for example, a company in the UK sourcing this fungus as it hasn’t as far to travel therefore will have less of a carbon footprint. However, they state that they collect this fungus by hand and that it is a local family business, so this particular material would perhaps not be suitable for large-scale production or for eventually having any prominent place in the fashion industry. However, the industry is becoming more conscious of small-business owners and the shift to buying more quality, handmade products is noticeable.It’s not just mushroom leather that is being looked into, there are many other companies developing alternative materials from other substrates such as fruit, pineapple leaves, tea, soy, coconut water and teak leaf (PETA, 2018). Dr Carmen Hijosa has developed ‘Piñatex’ – a natural textile material made from pineapple leaf fibres left over from harvest in the Phillipines. This material was developed from Hijosa’s personal experience working within the leather industry and witnessing first-hand it’s damaging impact (Rozas, 2018). This is why Piñatex focuses on the material’s social impact and incorporates a Cradle to Cradle approach (Piñatex, 2018). This guides manufacturers through an improvement process, focusing on areas such as material health, renewable energy and carbon health (C2ccertified.org, 2018).Fibres are extracted through a process called “decortication” which is carried out at the plantation (Rozas, 2018). By keeping part of the production of the material at the site of harvest, Piñatex are ensuring the livelihood of workers. Waste biomass is also used by local farming communities as fertiliser, therefore the collection of the fibre is a closed loop process. Piñatex undergoes industrial processes to make it into a textile material within which no toxic chemicals are used, unlike traditional leather (Ananas Anam, 2017). The material is currently not bio-degradable due to the coating that is applied, however they are working on developing a bio-based coating. Similarly, Piñatex is water-resistant and not waterproof, suggesting there is still a need for improvement if this material is to replace leather (Piñatex, 2018).It’s suggested that Hijosa saw a place for this type of material in the market and responded accordingly. (Rozas, 2018). Piñatex is suitable for a range of fashion applications due to qualities such as flexibility, breathability, strength and softness, in a similar way to mushroom leathers. It has already been used within industry for brands covering footwear, clothing and interiors. A dress made from Piñatex was worn to the Met Gala by eco-activist, Livia Firth (Rozas, 2018). This company is aware that the next stage is to stabilise its supply in order to reach demand levels but “does not compromise its mission and fundamental values” (Rozas, 2018). They aim to work with other pineapple-growing countries to create a commercial industry (Piñatex, 2018), sharing their knowledge and building the material’s integrity.Another alternative leather material being developed is made from apples. In a similar way to Piñatex, this material has the possibility to solve multiple issues across different fields, not just within the fashion industry (Michaud, 2017). It’s found that 30% of the food we produce gets thrown away (Michaud, 2017). If this could be used to produce a new material for fashion instead we would be able to save on waste and resources. This material made by The Apple Girl uses only 1 litre of water to produce 1m of fabric (Michaud, 2017) compared to 40-45L water/kg used by leather tanneries (Sundar et al., 2001).What potential issues may arise if we do replace leather with these new materials, if any?It’s easy to think that these alternative materials at first glance are the solution to all our environmental problems surrounding leather. If this is the case, then why hasn’t leather already been replaced? All of these different alternative materials boast different qualities that leather have but so far none have provided a perfect alternative. It may be that there is never an exact alternative to leather and that high-end luxury items will always choose leather over any other material, whether this be because leather is truly more fit for purpose or because of consumers long attachment and nostalgia with the material. These alternatives have the potential to at least replace cheaper products on the market but for this to happen consumers need to change the way they view these materials; “The biggest hurdle to the widespread adoption of fungal materials may, in fact, be us” (Stone, 2018).“If we can use plants to make a bio-based material that replaces something like leather, that has all sorts of environmental and social concerns surrounding it” (American Chemical Society, 2013). One such issue is that leather production is a huge industry that provides jobs for many workers (Meilach, 1972). The production of these alternative materials would need to be integrated into society in such a way that allows workers to maintain or transfer their jobs into the production of these new materials. Even if the movement to a more sustainable material does result in job loss, a lot of these workers are currently heavily suffering in terms of health issues, so this change may be worse in the short-term but better in the long-term for the majority if we ultimately wish to survive on Earth.ConclusionThe ideal alternative to leather would solve more than just the environmental issues with leather production, one that has the potential to improve the lives of farmers and support communities, such as Piñatex, would be a bonus. It’s clear that we are producing an extortionate amount of waste every year; From pineapple agriculture alone, this is 13 million tonnes (Piñatex, 2018). Putting this waste to use to develop alternative materials appears to have the potential to be a viable solution. However, different companies across the world are trying to re-create an existing material as opposed to developing a completely new one.The solution could lie in developing alternative materials to leather, but dependent on what their end use will be. Many of the companies this report has looked into have been solely trying to imitate leather in its entirety – it’s look, its feel, its qualities, however this may be irrelevant. If we can create a sustainable material that is suitable for its intended purpose, whether it be handbags, clothes or shoes then surely that should be enough. If we can in fact ‘design leather much better than an animal can” – Richard Wool (American Chemical Society, 2013) then why are we still trying to imitate leather and causing ourselves more hassle trying to overcome the environmental concerns involved with certain stages of production, just to imitate the surface quality of an existing material, for example? It is undeniable that materials such as mushroom ‘leather’ hold great potential for us in the fight for sustainability and in the fashion industry, however their integration must be carefully managed to ensure that sustainability remains the sole focus.ReferencesBooks Meilach, D. (1972) Contemporary leather. Chicago: RegneryQuilleriet, A. (2003) The Leather Book. 1st ed. USA: AssoulineStamets, P. (2005). Mycelium running. Berkeley: Ten Speed PressJournalsPringle, T. (2017) Establishing a Circular Economy Approach for the Leather Industry [online] Available at: https://dspace.lboro.ac.uk/2134/33499 [Accessed 16 Dec. 2018]Sundar, V., Ramesh, R., Rao, P., Saravanan, P., Sridharnath, B. and Muralidharan, C. (2001) Water Management in Leather Industry. Journal of Scientific and Industrial Research, 60, p.443WebsitesAmerican Chemical Society (2013) Green eco-leather could revolutionize fashion industry – American Chemical Society. [online] Available at: https://www.acs.org/content/acs/en/pressroom/newsreleases/2013/june/green-eco-leather-could-revolutionize-fashion-industry.html [Accessed 16 Dec. 2018]Anzilotti, E. (2018) This Very Realistic Fake Leather Is Made From Mushrooms, Not Cows. [online] Fast Company. Available at: https://www.fastcompany.com/40562633/this-leather-is-made-from-mushrooms-not-cows [Accessed 16 Dec. 2018]Ashoka Paris. (2018) ASHOKA Paris – une marque 100% végane [online] Available at: https://www.ashokaparis.com/pages/pourquoi-vegane [Accessed 16 Dec. 2018]BLC Leather Sustainability (2018) Is Synthetic Leather More Sustainable than Real Leather? [online] Available at: https://www.leathersustainability.com/are-synthetic-materials-more-sustainable-than-real-leather/ [Accessed 16 Dec. 2018]C2ccertified.org (2018) C2C Product Certification Overview – Get Certified – Cradle to Cradle Products Innovation Institute [online] Available at: https://www.c2ccertified.org/get-certified/product-certification [Accessed 22 Dec. 2018]Fruitleather Rotterdam (2018) The Project. [online] Available at: http://fruitleather.nl/home/project/ [Accessed 16 Dec. 2018]MycoWorks (2018) MycoWorks. [online] Available at: http://www.mycoworks.com/ [Accessed 16 Dec. 2018]PETA. (2018) Environmental Hazards of Leather PETA [online] Available at: https://www.peta.org/issues/animals-used-for-clothing/leather-industry/leather-environmental-hazards/ [Accessed 16 Dec. 2018]PETA. (2018) See the Ingenious Ways People Are Making Vegan Leather PETA [online] Available at: https://www.peta.org/living/personal-care-fashion/vegan-leather-chic-sustainable-and-fruity/ [Accessed 16 Dec. 2018]Piñatex (2018) Piñatex [online] Available at: https://www.ananas-anam.com/ [Accessed 22 Dec. 2018]Piñatex, R. (2018) Responsibility – Piñatex. [online] Piñatex. Available at: https://www.ananas-anam.com/responsibility/ [Accessed 16 Dec. 2018]Preuss, S. (2018) Sustainable textile innovations: mushroom leather. [online] Fashionunited.com. Available at: https://fashionunited.com/news/business/sustainable-textile-innovations-mushroom-leather/2018051421156 [Accessed 16 Dec. 2018]Rozas, A (2018) Sustainable Textile Innovations: Piñatex, the vegan alternative to leather [online] Fashionunited.uk Available at: https://fashionunited.uk/news/fashion/sustainable-textile-innovations-pinatex-the-vegan-alternative-to-leather/2017062925005 [Accessed 22 Dec. 2018]Stahl.com. (2018) Is leather sustainable? [online] Available at: https://www.stahl.com/en/is-leather-sustainable.htm [Accessed 16 Dec. 2018]Stone, M (2018) [online] Available at: https://gizmodo.com/the-technology-that-will-build-our-future-may-be-found-1693612047 [Accessed 16 Dec. 2018]VideosAnanas Anam (2017) This is Piñatex® [Online Video] 21 Nov 2017. Available at: https://www.youtube.com/watch?v=gCNuFqH4VCc [Accessed 22 Dec. 2018]?         Indie Bio (2016) Indie Bio – Demo Day #3 – MycoWorks [Online Video] 21 July 2016. Available at: https://www.youtube.com/watch?v=gZQGeQp4v-4 [Accessed 16 December 2018]Michaud, H (2017) the apple girl video pitch [Online Video] 26 Mar 2017. Available at: https://www.youtube.com/watch?v=29vGM7EghtA&feature=youtu.be [Accessed 22 Dec. 2018]?         SciFri (2016) The Fungi in Your Future [Online Video] 16 November 2016. Available at: https://www.youtube.com/watch?v=jBXGFOk5_Rs [Accessed: 16 December 2018]