Tannery production is circular by nature
The pillars forming the foundations of leather circularity are:
Be a raw material recovered from food industry waste
More than 99% of the raw hides used by tanneries come from cattle, sheep and goats raised exclusively for milk and meat production.
Such hides are therefore a waste product of the food industry, and are technically considered ABPs, or Animal By-Products, as defined in EC Reg. No. 1069/2009. The tanning process recovers these ABPs and transforms them, enhancing them into a final product, the finished leather, which has multiple applications in the market.
Therefore, leather is the result of one of the oldest re/up-cycling processes.
Every year, tanneries worldwide recover a total of around 1,700 sq km of raw hides and skins (equivalent to 8 million tonnes), the disposal of which as waste would produce 5 million tonnes of greenhouse gases (estimates based on UNIDO data).
Enable recovery of waste and other ABPs, water treatment and purification, reuse of chemicals (or chemical products)
The structure of the tanning sector in Italy has allowed the development of a highly interconnected cross-company ecosystem for the exchange of waste, effluents and services that are particularly relevant from an environmental point of view.
In fact, tanning waste recovery processes are an interesting application case history of circular bioeconomy; for example, the agricultural use of recovered tanning biomass, prevalent to date, exemplifies the ideal closing of the circle of natural materials.
In Italian tanneries, the main processing waste is recovered to produce:
Be a bio-based material
Given its origin, leather is for all intents and purposes a bio-based material derived from renewable sources: an important feature in the fight to reduce greenhouse gas emissions.
Click here to learn more about the bio-based nature of leather
Have unique technical characteristics
High durability and usability, high repairability, and a high level of biodegradability and compostability
The tanning process converts an organic waste into a stabilised, durable, high-performance production material with different end uses which is in most cases biodegradable.
Leather encapsulates several principles defined in the European Union’s Ecodesign Regulation stating that the performance and value of products, materials and other resources should be maintained for as long as possible to avoid the generation of waste, which, in any case, should have a minimal impact on ecosystems.
Durability/Usability and Biodegradability/Compostability are two of the hottest topics in the global debate on the sustainability of manufacturing materials.
Durability/Usability/Reparability
Leather can age while retaining its unique characteristics, thus conferring high durability in terms of both aesthetics and functionality, to the items it contributes to making.
In these terms, we can also speak of usability. In fact, in addition to remaining intact over time, leather also ensures that a product can maintain its basic characteristics despite frequent use.
As a result, these features also allow for a high degree of reusability and reparability, which further extends the life cycle of end products.
It can be said that leather items age with their owners, acquiring a vintage appeal over time. Therefore, when we speak of leather, we refer to the sustainable design approach that considers emotional durability, a factor that reduces the consumption and waste of natural resources by increasing the resilience of the relationships established between consumers and products.
Biodegradability/Compostability
First of all, from a technical-scientific point of view, it makes more sense to discuss compostability than biodegradability, since compostability, which is also more specifically regulated, measures the ability of a material to transform into compost (a mixture of substances obtained from biodegradable plant/animal residues through the action of bacteria and fungi) in a controlled period of time and under certain conditions, while the term biodegradability is more abstract and colloquial in that, in practice, it indicates the tendency of a material to be converted into CO2 thanks to microorganisms.
Biodegradability or biodegradation, which is not always a positive feature of sustainability, as it is important to make sure that what is produced can be made available again in the environment, without harming it, is a slow process carried out by nature, while composting is a fast process carried out by man.
When shredded and placed in appropriate humidity and temperature conditions in the presence of microorganisms, the leather goes through a process of biodegradation.
But it is important to remember that leather is still a composite material, composed of a polymer (collagen), which is itself biodegradable before it is tanned, and substances added to improve chemical and mechanical properties, the degree of biodegradability of which can vary even considerably.
The biodegradability of leather can be assessed through ISO 20136.
This is a topic that is receiving increasing attention in an analyses, both at the level of supply chain relations and at the regulatory level, and consequently increasing scientific studies are devoted to it. Some of them are highlighted below:
Is the biodegradability of leather in opposition to its durability?
The durability of a material is assessed by whether it can be used for a period under normal and reasonably predictable conditions, meaning temperature, humidity of the environment, atmospheric pressure. Under such conditions, leather is a durable material.
Monitor for Circular Fashion – SDA Bocconi
Among the various initiatives to promote circularity in the sector, UNIC and ICEC have joined the “Monitor for Circular Fashion” project, promoted by the SDA Bocconi Sustainability Lab with the participation of the European Commission (DG GROW), UNECE (United Nations Economic Commission for Europe), some fashion brands (including Kering, Ferragamo, Tod’s, Vivienne Westwood) and their suppliers.
The Monitor for Circular Fashion is a multi-stakeholder project, which aims to identify performance indicators (KPIs) of circularity in the fashion industry, highlight and disseminate good business practices in this regard, and enhance technical, managerial and scientific skills toward sustainable business models.
In the 2023 edition, UNIC and ICEC took part in the working group (KPIs Committee) that defined circularity KPIs for the leather supply chain, with the aim of emphasizing and clarifying their technical elements of recognition, evaluation and measurement, with a view to eco-design and according to principles of durability of the consumer good, biodegradability of the material and production efficiency.
UNIC and ICEC also contributed to the proper identification of leather sustainability claims as partners in the Monitor’s two pilot projects carried out by TOD’s project Re-Gen H, with leathers from Sciarada Industria Conciaria S.p.a and Ferragamo project Traced Leather Varina ballet flat, with leathers from BCN Concerie S.p.a.
In 2024, Gruppo Mastrotto S.p.a also joined the Monitor for Circular Fashion community while UNIC and ICEC renewed their collaboration and are still involved in two other new pilot projects concerning leather.