Sven

Material Selection

Sven
Material Selection

Material selection is the obvious stage at which to address sustainability. Whatever materials are chosen have a knock-on effect on the other stages in a shoe's lifecycle. This section aims to highlight the most commonly used materials in the footwear industry and provide information on the negative impact that they have on people and the environment. In contrast, we've listed some better alternatives that try to avoid these problems.

 
 

Common Materials

The following tables list commonly used materials for a shoe's upper, sole, heel and joining methods. These are materials chosen for their low cost combined with their ability for an easy and speedy manufacture. We've described why each material is used, how it's harmful to us and our environment, the size of it's impact and suggestions for better alternatives.

 

   UPPERS

MaterialDescriptionUseEffect on humansEffect on environmentSize of impactBetter Materials

Chrome-Tanned Leather

Chromium is a heavy metal used as a leather tanning agent.Chromium is a cheap, fast method of tanning leather. This leather is more likely to be soft, pliable and stable in water compared to other methods. [1] [2]Tannery workers exposed to Chromium are at risk of damage to gastrointestinal, respiratory and reproductive systems. Chromium is also carcinogenic. [1]Tannery waste contaminates water sources through negligence, e.g. dumping hides onto riverbanks. Contamination can accumulate in food sources e.g. local fish supplies. [2]16 million people are at risk of Chromium exposure globally according to the Blacksmith Institute. [1]
Formaldehye is a chemical compound (CH2O) used in tanning leather.Formaldehyde is used in a number of ways throughout the leather tanning process e.g. as an adhesive or as a tanning agent. The result is pale in colour so hides are referred to as "wet-white".Inhaled formaldehyde (at concentrations above 0.1ppm in air) can potentially result in watery eyes, headache, a burning sensation in the throat, and difficulty breathing. Formaldehyde is also classified as a carcinogen. [3]Exposure to formaldehyde can make animals sick, affect their ability to breed, and reduce their lifespan. Formaldehyde is highly toxic to aquatic life - the fish, shellfish and other creatures in our rivers, lakes and oceans.Formaldehyde tanning is nowhere near as common as Chrome tanning, but the health effects as a result of exposure in tanneries are known and it's being phased out.
Conventional (Non-Organic) CottonChemicals, referred to as pesticides, are used in cotton production to kill, repel or stop the growth of organisms, by impairing biological processes essential for living. The most commonly used pesticides are insecticides that go by the names of Malathion, Aldicarb and Parathion. [4]Pesticides are used to obtain a higher cotton yield.Pesticides also impact human health, not just the intended pest. The effects from poisoning range from headaches, vomiting and difficulty breathing to impaired memory, disorientation and severe depression. [4]After applying pesticides, rain often washes it away - this happens to 1 million tonnes every year due to excessive application. Major cotton producing countries, like the USA and India, have detected pesticides in their water resources. [4]The EJ Foundation says that "cotton is the world’s most important non-food agricultural commodity" [4], but cotton production means that there are 7 million people at risk to pesticide exposure. [2]
Basic (Cationic) DyesDyeing is a method of applying colour to a textile. This can happen at any stage in the manufacture process; dyes can be applied to fibres, yarn, fabric or a completed article of clothing.Basic dyes dye acrylic fibres.Dyes are made from a variety of chemicals and compounds e.g. sulfuric acid, chromium, copper and other metallic elements. "The World Bank estimates that textile dyeing and treatment contribute up to 17-20% of total industrial water pollution." [5] This pollution can enter the water supplies of local communities and wildlife. "Conventional textile dyeing is extremely water and chemical-intensive: for every two pounds of textiles dyed, 25-40 gallons of water is used." [6]
Acid DyesAcid dyes dye protein fibres (e.g. wool, silk) and nylon.
Disperse DyesDisperse dyes dye polyester yarn.
Vat DyesVat and direct dyes dye cotton yarn.
Direct (Substantive) Dyes
Durable Water Repellent (DWR) treated fabricsThe Greenpeace 'Detox Outdoor' campaign describes PFCs as "a family of man-made, fluorine-containing chemicals".The purpose of using PFCs is to make clothing and accessories waterproof.PFCs can accumulate in the human body - they've been detected in blood and breast milk around the world. [7] "Research has shown that some PFCs cause harm to reproduction, promote the growth of tumors and affect the hormone system.” [8]PFCs are resistant to breakdown and have the potential to remain in the environment for hundreads of years. Research on animals has shown PFCs cause tumors, cancer and reproductive problems. [8]"Several scientific studies have already shown that PFCs can be found around the globe, including in remote areas." [8] “Even if production were to end today, PFC pollution would remain the environment for many years to come.” [7]
PVC (polyvinyl chloride)
See Sole - PVC (polyvinyl chloride)
 

   Soles

MaterialDescriptionUseEffect on humansEffect on environmentSize of impactBetter Materials
Chrome-Tanned LeatherChromium is a heavy metal used as a leather tanning agent. Leather is commonly used as an outsole.
See Upper - Chromium
Vegetable-Tanned Leather

PVC (polyvinyl chloride)

A versatile plastic that accounts for 20% of all plastics manufactured worldwide. [9]In footwear, PVC is often found in outsoles as well as synthetic leathers and coated fabrics for a shoe's upper.Directly (from oil extraction e.g. rashes, chronic headaches, vomiting for those living near oil extraction sites with severe long term effects like lung disease, liver and kidney damage and miscarriages) [10] and indirectly affected (through environmental damage i.e. you eat what your fish supply eats).Crude oil extraction causes problems like deforestation, oil spills, pollution of toxic chemicals. [10] [11] From the 100 million tonnes of plastic produced each year, 10 million tonnes ends up in the sea. Plastic doesn't break down like natural materials - there's an area of floating plastic the size of Turkey in the North Pacific. [12]Oil spills are difficult to clean up and described as impossible, in the case of Artic oil reserves. [1]Bioplastics
PUA rigid type of polyurethane plastic.Used in outsoles because of it's flexibility, resistance to abrasion, strength and durability. [13]
TPU (thermoplastic polyurethane)An elastic, flexible type of polyurethane plastic.Used in outsoles because of it's elasticity, flexbility and resistance to abrasion, impact and weather.
EVA Foam (ethylene vinyl acetate)A low-density elastomeric copolymer of ethylene and vinyl acetate. To provide a level of flexibility, bounce and comfort in shoe's insoles and midsoles.
Petroleum-based RubberA tough, elastic polymer.Used in outsoles.Rashes, chronic headaches, vomiting for those living near oil extraction sites with severe long term effects of exposure like lung disease, liver and kidney damage and miscarriages. [10]Crude oil extraction causes the problems like deforestation, oil spills, pollution of toxic chemicals. [10] [11]To put synthetic rubber production into context, aproximately 70% of all rubber used is synthetic. [14] When oil spills occurs, they're difficult to clean up and described as impossible in the case of Artic oil reserves. [11]
Illegally Logged Wood""Illegal logging and related trade occurs when timber is harvested, transported, processed, bought or sold in violation of national or sub-national laws." [15]Used in midsoles for wedges and platforms.Illegal logging aids deforestation, the loss of biodiversity and climate change. "This creates social conflict with indigenous and local populations and leads to violence, crime and human rights abuses." [16]Illegal logging aids deforestation, the loss of biodiversity and climate change. [16]In 2015, illegal imports accounted for nearly 10% of total trade. [17] "It is estimated that some 1.6 billion people worldwide depend on forests for their livelihood and 60 million indigenous peoples depend on forests for their subsistence." [16]FSC-Certified Wood
 

   Heels

MaterialDescriptionUseEffect on humansEffect on environmentSize of impactBetter Materials
ABS (Acrylonitrile Butadiene Styrene)ABS is one of the plastics used to make heels. It's a low cost, easy to machine plastic with good impact resistance, strength and stiffness.ABS is moulded to create high heels and is reinforced with an internal tube of metal.Directly (from oil extraction e.g. rashes, chronic headaches, vomiting for those living near oil extraction sites with severe long term effects like lung disease, liver and kidney damage and miscarriages) [10] and indirectly affected (through environmental damage i.e. you eat what your fish supply eats).Crude oil extraction causes problems like deforestation, oil spills, pollution of toxic chemicals. [10] [11] From the 100 million tonnes of plastic produced each year, 10 million tonnes ends up in the sea. Plastic doesn't break down like natural materials - there's an area of floating plastic the size of Turkey in the North Pacific. [12]Oil spills are difficult to clean up and described as impossible, in the case of Artic oil reserves. [11]
 

   JOINING METHODS

MaterialDescriptionUseEffect on humansEffect on environmentSize of impactBetter Materials
Solvent-Based AdhesivesHazardous chemical subsances used in the manufacturing of adhesives e.g. Benzene and Toulene. [18]Adhesives used in shoe construction, and more often that not, in cheap, poor quality shoe construction.Chinese shoemakers were reported to have high levels of exposures to benzene, toluene and other toxic solvents. [18] The solvents in Benzene are reported to cause harm to the respiratory system and brain, and is classified as a carcinogen.Organic solvents react in the atmosphere in sunlight, producing an air pollutant known as 'ground-level ozone'. Solvents are slow to break down in water and soil, posing a threat to groundwater aquifers and ecosystems and can remain in the environment for decades.UnknownWater-based adhesives
 
 

Better Materials

Looking for sustainable footwear materials? Having put together a list of commonly used materials, it's only right for us to suggest some better alternatives for a shoe's upper, sole, heel and joining methods. Most are commercially available and have already been put to good use by other brands, whilst others are still in development and offer promising solutions.

 

   UPPERS

Alternative forMaterialDescriptionAvailabilitySustainable qualitiesOther benefitsDisadvantagesExamples of use

Leather

Uppeal™

 Formally know as Appleskin; a vegan alternative to leather developed by Frumat and produced by Mabel (both Italian based). Made from the fibrous waste recovered from the apple juice industry. Commercially available Made by repurposing waste from the Italian apple juice industry. 50% bio-based. The waste fibre is dried and crushed into a fine powder which is mixed with pigments and a binder, then spread over a canvas until it solidifies into a skin-like material. Wide selection of colours Contains PU coating - not breathable Humans Are Vain, Good Guys, Sylven, Womsh
BeLeaf™ A vegan leather alternative developed by a Brazilian company Nova Kaeru, derived from the large tropical plant leaves (called ‘Elephant Ear’) and tanned with an organic process. Commercially available The tropical plant leaves are not monoculture, commercial crops – they are renewable resources that grow freely on the banks of forests and rivers. Nova Kaeru has developed its own organic, environmentally safe, chrome-free tanning technology based on a blend of biodegradable acrylic resins, polymers, glutaraldehyde, synthetic & vegetable tannins. Comes in a confined leaf shape and its natural distinctive texture The Shoe Surgeon
BioVeg Developed by Italian producer Coronet. Made with recycled polyester from plastic bottles and bio polyols, obtained from non-food and GMO-free corn crops Commercially available Vegan with up to 81% biomass Wide selection of finishes and colours Contains plastic - not breathable Yatay
Biocouture A bacterial cellulose fabric, grown from fermented tea, bacteria, yeast and other microorganisms. Biofabrication technology has been adapted by a number of start-ups in recent years, see below examples: Modern Medow, Fine Mycelium and Mylo This leather alternative is a non-animal-based material that could be made from waste streams e.g. food processing plant. It's also biodegradable. Substantially reduces carbon footprint compared with animal-based leathers. Emerging game-changing technology that should become more accessible in the near future Liz Ciokajlo
Cellulosic Fiber
Desserto® (Cactus Leather) Vegan alternative to leather produced by Mexico-based company Adriano di Marti. Nopal cactus is the basis for this material. Commercially available The cactus plantation is fully organic with no herbicides and pesticides used, and no harm to biodiversity. A renewable resource as the cactus re-grows after harvesting. It grows from rainwater alone. PETA certified Not entirely bio-based but according to Desserto the Polyester content is recycled rather than virgin Clae, Saye, Carmona, MoEa, Onitsuka Tiger
Celium™ Developed by Spanish biotch firm Polybion, Celium is a vegan alternative to leather, made from cultivated cellulose which is grown by feeding bacteria with agroindustrial fruit waste. In a pilot phase Growing Celium’s cell-based membrane by feeding bacteria with agro-industrial fruit waste. Converting waste into nutrients that initiate new growth. Ganni
Forager™ Mycilium based ulternative to leather officially launched in 2022 by US-based mycelium tech company Ecovative following years of R&D. Commercially produced “Grown in only nine days, Forager™ pure mycelium hides are 100% vegan." "with naturally high tensile strength, tear resistance, durability, and other traits that are equal to animal leathers.” Ecco, Pangaia, Reformation, Vivobarefoot, Wolverine

Cork Sheeting

 Made from the bark of the cork oak tree, often laminated with an ultra thin clear film to provide better flexibility and durability Commercially available "It is a 100% natural raw material, that is 100% reusable and 100% recyclable, extracted from cork oaks without harming the normal development of the species and without damaging the tree." [19] Cork is a soft, lightweight, compressible and hypoallergenic material. It can be scratched or dented when under pressure. Not breathable. Nae, Nike

Reishi™

 Biofabricated leather substitute engineered by MycoWorks that is grown from mycelium and agricultural byproducts. In development MycoWorks' material is manufactured in a closed-loop process using "abundant, natural fibers to create 100% biodegradable materials, making this an infinitely renewable technology". [43] The material is also animal-free. The MycoWorks material can compete with conventional leathers due to it's strength, flexibility and durability. This is a cost competitive leather substitute because it "takes a fraction of the time and resources to grow" [43] in comparison to making leather from raw hides Seem to be exclusive to one brand at this stage Hermès

Bio-Tex™

 Leather alternative developed by US-based company Modern Meadow. Derived from upcycled material (of which 64% are bio-based), and married with bio polymer Bio-Alloy™. In a pilot phase Produced with 83% less water consumption and 91% less GHG emissions - compared with chrome-tanned leather. Tory Burch, Everlane
Fruitleather Also known as Mango leather, made from discarded mangos by Rotterdam based start-up. Commercially available A vegan material derived from leftover mangoes sourced from fruit markets that would otherwise be thrown away. The mangos are mashed and boiled and include other “natural additives”, then spread out in sheets to dry. The textile backing is made from GOTS certified organic cotton. Comes in 40cm x 60cm sheets with limited capacity - currently produce about 50-70 square meters a month Saye
GrapeSkin® / Vegea™ Vegan alternative to leather made from a byproducts of the Italian wine industry by Milanese company Vegea, founded by architect Gianpiero Tessitore in 2016. Commercially available Made by repurposing waste from the Italian wine industry (discarded grape skins, stalks and seeds) "Free from toxic solvents, heavy metals and harmful substances" Unknown / await further information from Vegea Le Coq Sportif, Pangaia, Mr Porter, H&M
Mirum® Made by US-based company Natural Fiber Welding, Mirum is a high-performance plant-based material with 100% natural inputs and zero use of plastic Commercially available 100% plant-based material made with natural rubber, minerals, and other natural plant-sourced materials such as waste cork power and coconut coir fibre. Plastic-free, Requires no water during manufacturing and dyeing Due to the high demand, there is a waiting list for new brands Allbirds, BMW, Baabuk, Camper, Pangaia, Nooch, Ralph Lauren, Unless
Oval A plastic-free collagen skin substrate. Created from surplus collagen and enriched with natural oils, developed by UK-based start-up Pact In development A natural byproduct of freshwater fish farming, made with 100% transparency. "Soft, smooth handfeel, reminiscent of leather, with supreme suppleness, drape, recovery, strength and performance" Not vegan
Pinatex™A non-woven textile made from pineapple leaf fibres.Commercially available“Piñatex fibres are the by-product of the pineapple harvest. No extra land, water, fertilizers or pesticides are required to produce them.” [21]Piñatex™ is a strong, breathable, soft, light and flexible textile. Various thicknesses and finishes are available, and the extraction of pineapple leaf fibres creates additional revenue for the farmers. Pinatex Original is 95% bio-based, whereas their Performance line is less than 50% bio-based Paul Smith, Nike
Treekind®100% bio-based, vegan flexible leather-like material, developed by UK-based start up Biophilica.In a pilot phaseEntirely plastic-free, made from urban plant waste like leaves and twigs which are locally sourced from parks and gardens, combined with lignocellulosic feedstock with a natural binder.Treekind can be home composted as verified in the ISO 14855-1 test. It uses less than 0.1% of the water in leather production. Bestseller, Vyn
Chrome-tanned leather (a.k.a. wet blue)Vegetable-tanned leatherVegetable tanning uses tannins that occur naturally in the leaves and bark of certain plants.Commercially availableAvoids the use of toxic chemicals like Chrome, instead using naturally occuring tannins.UnknownVegetable-tanned leather isn't as soft and pliable as Chome-tanned leather. Vegetable tanning is also a more time-intensive process. CYDWOQ, Guat Shoes, Trippen
Rhubarb leather®A form of vegetable tanning but using tannins extracted from rhubarb roots.Commercially availableAvoids the use of toxic chemicals like Chromium, instead using naturally occuring tannins. Also, Rhubarb leather® is fully produced in Germany. "Even the rawhides come from regional resources with short transport distances" [22]Rhubarb leather® is suitable for allergy sufferers because no chromium salts or heavy metals are used.Whilst it offers a safer alternative to traditional Chromium tanning, it is still a method of tanning leather - a material that is ethically challenging.Deepmello
wet-green®An environmentally friendly tanning agent to provide an alternative, sustainable method of tanning leather. wet-green® is an example of biomimicry, using the same substance that the leaves if the olive tree uses to ward of predators.Commercially availableCompletely harmless across the entire value chain through eliminatinating the use of substances like acids or salts. Also, "No tree is felled, no plant sacrificed and no fields cultivated which would otherwise be used to produce food". [23]It produces a similar quality to Chrome-tanned Leather with a softness, lightness and durability. wet-green® also has a pleasant fragrance in contrast to foul smell of Chrome-Tanned Leather. [23]Whilst it offers a safer alternative to traditional Chrome of Formaldehyde tanning, it is still a method of tanning leather - a material that is largely, not ethical.BMW

Suede/ Nubuck

 Ultrasuede®A man-made suede / nubuck alternative, derived from recycled polyester.Commercially available"Recycling polyester means reducing energy consumption and CO2 emissions into the atmosphere by 80% compared to the traditional virgin polyester production process."Ultrasuede® is machine washable and resistant to stains and discolouration.Unknown
Dinamica®Made-in-Italy water-based microfibre produced in part by using recycled polyester (the recycled content varies according to the product line and application), and without the use of solvents.Commercially available"Dinamica® is designed for easy disposal, and is 100% recyclable at the end of its useful life."Certifide Vegan by PetaUnknownBeyond Skin

Conventional Cotton

Bast Fibres Bast fibres are a group of natural fibres that are extracted from the stem of certain plants e.g. flax (linen), hemp, jute and stinging nettles.Commercially availableBast fibres can be grown with fewer imputs, like without pesticides and smaller areas of land. They can also be grown in European climates, providing alternatives as oil prices and transportation costs rise.Bast fibres are durable and flame retardant.However, bast fibres are not as soft as cotton.
Bananatex® Plant based technical fabric made entirely from the Abacá banana plants.Commercially availableCultivated in the Philippine highlands within a natural ecosystem of sustainable mixed agriculture and forestry, the plant is self-sufficient, requires no pesticides, fertilizer or extra water.Abacá plant has several stalks that can be harvested once a year, and regenerate fully within one year. Cradle to Cradle Certified.
Polyester-Based FabricsBiosteelAn artificial silk fibre created using the same proteins that spiders use to make their silk.Commercially available100% biodegradable once placed in water with the digestion enzyme called proteinase within 36 hours. [42]Biosteel is 15% lighter [42] than traditional polymer shoes and offers controlled moisture management - ideal for atheletes. The fibre is also non-allergenic, vegan.UnknownAdidas
ClimatexA biodegradable fabric primarily used to upholster office furniture.Commercially available100% biodegradable, "safe enough to eat" [25], scraps are sold on to farmers as mulch, improved the local water supply, high quality water treatment.Climatex is a forward thinker - sharing the recipe for their fabric free of charge. "It’s not really green thinking if we just hold that information secret." Bonnie Sonnenschein [25]UnknownPo-Zu
Thread InternationalA range of recycled PET fabric.Commercially availableMade from "100% post-consumer recycled content responsibly sourced from Haiti or Honduras" [26]. Thread International provides "Ground to Good™ traceability at all levels of the supply chain from bottle collection to fabric production." [26]A variety of options are available e.g. jersey, canvas and denim.UnknownTimberland

Conventional Dyes

Low-Impact Reactive DyesReactive dyes are a class of coloured organic substances that tint fabrics through chemical bonding between the fibre and molecule of the dye. [27]Commercially available"Generally, low impact dyes do not contain toxic chemicals or mordants (which fix the dye to the fabric), require less rinsing and have a high absorption rate in the fabric (~70%). High absorption rates and a decreased use of rinse water create less waste water." [28]"Reactive dyes were originally used for cellulose fibers only but now their various types are used for wool, silk, nylon, acrylics and their blends as well." [29]Reactive dyes are made from synthetic petrochemicals like environmentally damaging dyes, the method requires a high concentration of salt, and it's an expensive process in comparison to conventional dye methods. [28]Unknown
DyeCooDyeCoo is a method of dyeing fabric that uses "uses reclaimed CO₂ as the dyeing medium in a closed loop process" instead of water. [30]Commercially available"No process chemicals, no water, no waste water and therefore no waste water treatment is necessary." [30]"Short batch cycles, efficient dye use, no waste water treatment all contribute to significantly reduced operating costs." [30]DyeCoo's technology can only be applied to polyester fabrics.Nike

PFC-free membranes

SympatexA PFC-free membrane that "absorbs the water vapour and removes it through the clothing to the outside. This keeps the body warm and dry even in extreme situations.” [31]Commercially availableIt contains no PTFE (Polytetra-fluoroethylene) whose manufacture, disposal and incineration can release harmful substances. Sympatex can also be recycled using existing methods, e.g. PET bottles.Sympatex is machine washable, wind proof and has elastic properties.UnknownVaude
PFC finishes

Bionic-Finish®EcoA water, oil and soil repellent finish for textiles.Commercially available“No perfluorinated compounds are used for manufacturing BIONIC-FINISH® ECO products." [32]There is no impact on breathability.Unknown
  • H&M
  • Po-Zu
    • NikwaxA water-based wax finish that waterproofs products.Commercially availableNikwax is a non-toxic way to waterproof gear without the use of fluorocarbons or propellant gases. It's also not animal tested.Machine washableAn extra step of prewashing (using a Nikwax product) is recommended, which removes any existing dirt. Reapplication is suggested, every 4-6 washes or once a year.
     

       Soles

    Alternative forMaterialDescriptionAvailabilitySustainable qualitiesOther benefitsDisadvantagesExamples of use

    Petroleum-based Rubber

    		 Pliant™ Developed and produced by US-based firm Natural Fiber Welding (NFW), PLIANT™ outsoles are the world’s first naturally cured performance outsoles, made with sustainably sourced natural rubber and NFW’s patented plant-based curative. Commercially available. 100% bio-based / plastic-free. Made with the sap of the Hevea brasiliensis trees from certified responsibly managed forests. PLIANT™ is both naturally circular and mechanically recyclable. The compound can be used with exsisting rubber sole moulds through NFW's sole manufacturers' partners.
    BioCir®flex Developed by material science company Balena, BioCir®flex is an advanced, flexible, and fully compostable thermoplastic elastomer. Commercially available. Reach its end-of-life through complete decomposition and biodegradation in industrial compost facilities. Can be processed in various ways: injection molding, extrusion and a Filament for 3D printing.
    • Forever
    • Vivobarefoot
    Gum-Tec® UK-based company Gumdrop source post consumer chewing gum waste from their distinctive bright pink recycling bins. They recycle waste gum to create a range of alternative rubber and plastic compounds. Commercially available. Innovative solution of waste management. Only contains 20% recycled gum.
    • Adidas
    Kuori Backed by the EU's Horizon Programme, Kuori is a Swiss cleantech start-up that leverage food byproducts - such as olive pits, banana peels, and walnut shells - to produce elastic materials that are bio-based and biodegradable. In development. Safely break down in industrial composting, meeting EN 13432 standards.

    PU or EVA Foam

    		 Cork Cork is a natural material harvested from the bark of the Cork Oak tree. It has many benefits owing to its layered cell like structure which offers great elasticity and ensures it can be compressed easily without losing flexibility. Commercially available It has a natural resistance to moisture and liquid penetration. Together with its natural ability to absorb vibrations, it is a perfect choice for shoes, providing bounce and flexibility underfoot It’s also lightweight and biodegradable. Less cushiony than EVA. Limits in sole shape due to relatively large granules when moulded. Prone to breakage if moulded too thinly and this is perhaps the reason why it’s used more in casual sandal's mid-soles. Birkenstock, Giesswein
    Bloom Algae Rise by Bloom is an algae-blended resin containing a significant fraction of algae biomass and bio-based additives, suitable for sheet foam, injection foaming, and compression moulding Commercially available Renewable content of at least 45% Algae is one of the fastest growing plants on Earth which is also abundant Majority of content is non-bio/ non-renewable Vivobarefoot, Hylo, Saola, Puma, Reebok
    Sugarcane Also known as SweetFoam™ - an an open-source technology developed by Allbirds in partnership with Brazilian producer Braskem. A bio-based EVA resin, derived from Sugarcane. Commercially available Fast growing crop, and carbon-neutral production. Bio-based content is at least 60% Excellent technical properties such as lightness, resistance and cushioning Source from Brazil only Allbirds, Adidas, Dansko, Veja
    XpreSole Developed by Taiwan based brand Ccillu, using recycled used coffee grounds Commercially available Vegan, contains 30% recycled used coffee grounds / 70% petroleum-based Provides an "Odour-Control" property. The brand recently developed an innersole and upper material from the same compund. Bio-based content is a relatively small proportion Ccilu
    Cleancloud® A colaboration between the athletic shoe brand On with LanzaTech, and Borealis. An EVA foam made from captured carbon emissions In development Captured carbon monoxide (emitted from industrial sources like steel mills before being released into the atmosphere) is fermented with the aid of bacteria and is converted to liquid ethanol. The ethanol is dehydrated to create ethylene, then polymerized to become EVA On

    Petroleum-Based Plastics

    		BioplasticsAccording to European Bioplastics, if a plastic material is either biobased or biodegradable, it can be called a bioplastic. [35]Commercially availableSome bioplastics are made from natural, renewable materials, some biodegrade after use and some can do both. "Some biopolymers, such as PLAs and PHAs, have shown early promise as more sustainable alternatives." [36]Some bioplastics mimic tradition petroleum-based plastics in their appearence and performance.There's a lot of variation within the bioplastic family: "Some have trouble standing up to even moderately high temperatures. Some become brittle at even moderately low temperatures. Some are simply too expensive to be manufactured as plastics on a large scale." [36]One Moment

    TPU

    		EcoTPUA bioplastic alternative for TPU.Commercially availableEcoTPU is made with 60% of the material from renewable plant origins.EcoTPU holds the same properties as oil derived TPU.Unknown
     

       Heels

    Alternative forMaterialDescriptionAvailabilitySustainable qualitiesOther benefitsDisadvantagesExamples of use

    Illegally Logged Wood

    		FSC-Certified WoodFSC (Forest Stewardship Council) "is an international, non-governmental organisation dedicated to promoting responsible management of the world‘s forests." [37] They have developed a certification for responsibily sourced wood, paper etc.Commercially availableFSC certified operations increase the size and number of protected forest areas, retain wildlife habitats and retain carbon longer. [38]FSC certification has social and economic benefits like helping to resolve conflict with local communities and preventing unauthorised activities e.g. harvesting. [42]It's possible for companies holding FSC certification to potentially trade in illegal products. "A company can hold FSC certificates, but that does not mean that all of its products are necessarily FSC certified." [39]
    Petroleum-Based PlasticsBioplastics
    See Sole - Bioplastics
     

       JOINING METHODS

    Alternative forMaterialDescriptionAvailabilitySustainable qualitiesOther benefitsDisadvantagesExamples of use

    Solvent-based glues

    		 Renia Aquilim 315A water-based glue.Commercially availableFree from solvents.Provides safer working conditions, especially in poor ventilated areas.Renia Aquilim 315 is water resistant, but it's best used for applications where it won't constantly be exposed to water.Lisa Sorrell
    Irutex™ FI 4006 1K Po-Zu
    Ecostick ® 1820 1K Carréducker
     

    Looking to continue your materials research? Try the following:

    References