
With the contribution of the LIFE programme of the European Union.
Currently, over 85% of the leather produced worldwide is tanned with Cr(III) salts due to its low cost, versatility of use and high quality of finished products. However, Cr(III) can oxidise into toxic and carcinogenic Cr(VI), both in finished leather and in wastewater.
The remaining hides are tanned without chrome salts, using synthetic tannins and aldehydes, that confer to finished leathers inferior physical and mechanical characteristics compared to chrome tanned leathers.
Also in this case, there are some health and environmental issues due to the hazardous substances used or released during the making of the leather and its entire life cycle. Moreover, some of these substances are being classified as more harmful.
Although extremely eco-friendly, natural tannins are suitable for a reduced number of applications and generate high chemical load in wastewater in terms of Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD), due to the presence of non-tanning Low Molecular Weight Substances (LMWS).
Chrome Tanning Process (CTP)
Good physical and mechanical properties
Heavy metals;
Risks of toxicity and carcinogenicity by Cr(VI).
Syntans / aldehyde Tanning Process (STP)
Chrome-free white leathers
Concern in raw materials;
New hazard classifications.
Natural tannins Tanning Process (NTP)
Bio-based
COD / BOD impact on waste waters by non-tanning substances
LIFE I’M TAN project aims to validate, on a semi-industrial scale (TRL8), the use of innovative, sustainable Chemically Modified Natural Tannins (CMNT) to produce eco-friendly, high-quality leathers for a wide range of articles, such as footwear, handbags, and leather goods. The project involves a 3 year period, with effective start date on 01/09/2021 and closure scheduled on 31/08/2024.”
The leather tanning processes using these CMNT will have lower chemical hazards, sustainable costs, reduced waste and improved circularity (recycle/re-use of waste) compared to the conventional processes from based on chrome, synthetic tannins, and aldehydes thanks to:
The results of the I’M-TAN project will be measured according to different parameters linked to circular economy and sustainability principles. This is what we aim to reach:
With the contribution of the LIFE programme of the European Union.