{"id":58782,"date":"2026-02-26T16:00:39","date_gmt":"2026-02-26T15:00:39","guid":{"rendered":"https:\/\/www.swedishtanners.se\/?p=58782"},"modified":"2026-03-12T13:34:23","modified_gmt":"2026-03-12T12:34:23","slug":"cotance-news-1-2026-january-february-2026","status":"publish","type":"post","link":"https:\/\/www.swedishtanners.se\/en\/2026\/02\/26\/cotance-news-1-2026-january-february-2026\/","title":{"rendered":"COTANCE News 1\/2026 – January-February 2026"},"content":{"rendered":"

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Durability & Biodegradability: <\/strong><\/h1>\n

Is There a Contradiction?<\/strong><\/h1>\n

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Leather is known for its durability and performance<\/strong>. At the same time, it is being increasingly discussed in the context of biodegradability, circularity, and the bioeconomy.<\/p>\n

At first glance, this may seem contradictory. How can a material designed to last also be biodegradable?<\/p>\n

In this edition, developed together with Elisabetta Scaglia<\/a>, Head of Environmental Services at UNIC<\/strong> \u2013 Concerie Italiane<\/a> & Dietrich Tegtmeyer<\/a>, Freelancer for Leather – we clarify common misconceptions and explain \u2014 in clear, evidence-based terms \u2014 how durability and biodegradability can coexist in leather.<\/p>\n

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\u00a0Understanding the Basics<\/strong><\/h3>\n

When it comes to leather – durability and biodegradability are not opposites<\/strong>. They operate on different timeframes<\/strong> and under different conditions<\/strong>.<\/p>\n

Leather is produced from animal hides and skins, which are rich in collagen \u2014 a natural, bio-based protein structure. Through tanning, this collagen structure is cleaned from impurities and stabilised to ensure that bacteria can no longer use it as a food source, effectively stopping the rotting (putrefaction) process.<\/p>\n

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\u201cTanning is a process that converts a putrescible organic material into a stable material that resists decomposition caused by microorganisms, thereby increasing its durability<\/em>\u201d<\/p>\n

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Elisabetta Scaglia<\/strong>
\nHead of Environmental Services and Specifications, UNIC – Concerie Italiane.<\/p>\n

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This stabilisation does not remove leather\u2019s natural origin<\/strong> \u2014 it changes however, the chemical nature of the fibrous collagen structure so that it remains stable, flexible, and durable. Its use in consumer products allows them to be used for many years, reducing waste and avoiding premature disposal.<\/p>\n

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Tanning Chemistry vs Biodegradability:
\nClearing the Confusion<\/strong><\/h3>\n

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One of the most widespread misconceptions is that tanning relies on so many chemicals that leather must then be \u201csealed\u201d with a heavily plasticised finish \u2014 effectively turning leather into plastic<\/em>. This is incorrect<\/strong>.<\/p>\n

What Tanning Does:<\/strong>
\n\u25cf\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0crosslinks collagen fibres by means of vegetable, mineral or synthetic tannins depending on the end-use (shoes, bags, gloves, furniture…)
\n\u25cf\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0improves resistance to heat, moisture, and mechanical stress thanks to selected performance chemicals
\n\u25cf\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0by definition when a surface coating or surface layer is applied to protect “leather” it cannot be thicker than 0,15mm, otherwise it has to be called “coated leather” and even in such a case the coating cannot be thicker than 1\/3 of the total thickness of the material.<\/p>\n

What Tanning Does NOT Do:
\n<\/strong>\u25cf\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0it does not convert leather into a synthetic material
\n\u25cf\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0it does not eliminate its natural, protein-based structure<\/p>\n

It is true that after tanning, the surface of leather has to be protected to allow for longtime usage, and in many cases this is done with a synthetic layer. But this layer is very thin (< 150 \u00b5m). Therefore, normally < 5% of the leather<\/strong> in use is based on plastic.<\/p>\n

As a result, despite the use of chemicals and protective layers, a sustainable leather today contains >90% natural based materials, allowing for far better biodegradability performance compared tomany other so-called biobased alternatives.<\/strong><\/p>\n

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Biodegradability in Practice<\/strong><\/h3>\n

Biodegradable materials are substances capable of being broken down by microorganisms (bacteria, fungi, algae) and natural elements (sun, water, oxygen) into non-toxic, natural components like water, carbon dioxide, and biomass. \u00a0<\/em>As Elisabetta Scaglia<\/strong> explains:<\/p>\n

\u201cBiodegradation is the metabolic conversion of an organic material into simpler natural elements through the action of microorganisms under suitable environmental conditions.\u201d<\/strong><\/em><\/p>\n

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A material with a higher proportion of bio-based chemistry may have a greater propensity for biodegradation but the two terms cannot be used interchangeably. More broadly, all leather is biodegradable in principle<\/strong>. However, for leather to biodegrade – like other natural materials (e.g. wood) – it needs the right conditions, which do not normally occur during use. The rate of biodegradation depends heavily on the environmental conditions and the presence of appropriate microorganisms.<\/p>\n

What varies is the speed of degradation, depending on the tanning and finishing chemistry that is used.<\/p>\n

Biodegradation does not occur while leather is being used, because the necessary conditions \u2014 sustained moisture, microbial activity, temperature, and oxygen \u2014 are typically absent. At the end of life, however, these conditions can enable biological breakdown. If leather as waste ends up in the environment, the degradation process starts for all its bio-based components.<\/p>\n

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Why This Matters for Sustainability and Circularity<\/strong><\/h3>\n

Durability and biodegradability position leather as:<\/p>\n