Tanning is an essential process for transforming hides into durable and resilient leather. However, the use of metal-based tanning, commonly employed in traditional mineral tanning, has raised concerns for both the environment and human health. In response to these issues, alternative solutions have emerged, with the most comprehensive and advanced being the metal-free technology, which is revolutionizing the tanning sector.

What is Metal-Free Tanning?

The Metal-Free tanning process, as indicated in point of the UNI EN 15987:2023 standard (Leather – Terminology – Key Definitions for the Leather Trade), stipulates that the sum of concentrations of all tanning metals (Aluminum, Chromium, Iron, Titanium, and Zirconium) detected in the tanned leather must be less than or equal to 0.1% (or 1,000 ppm), expressed as the total weight of metals to the total weight of dry leather.


Below are the advantages of metal-free tanning:

  • Reduced Environmental Impact: It represents a more ecological option compared to traditional tanning as it does not require the use of tanning metals, which can be harmful to the environment if not handled properly. This helps reduce the risk of water and soil pollution. Additionally, leather tanned without metals tends to have better biodegradability compared to chrome-tanned leather. This is important for reducing the environmental impact of leather products at the end of their lifecycle.
  • Health Safety: Metal-free tanning is safer for human health as it reduces the risk of exposure to tanning metals, which can be harmful to tannery workers and those using tanned leather products. Metal-free tanned leather is often considered more suitable for producing products in direct contact with human skin, such as shoes, bags, and clothing, as it reduces the risk of potential allergic reactions caused by metal residues in tanned leather.

Product Quality

Technological advancements have led to the development of new chemicals and processes that enable the production of high-quality leather with characteristics similar to, and in some cases superior to, traditional leather. This aspect is contributing to the increased acceptance of metal-free tanning in the industry.

Challenges and Opportunities

Despite numerous advantages, the adoption of metal-free tanning still presents some challenges. The main challenge involves upgrading current tanning infrastructures to support this technology. Investment in new equipment and training of personnel for the effective implementation of the new tanning process is essential. However, this transition also offers exciting opportunities. The metal-free tanning industry can meet the growing demand from environmentally conscious consumers. This opens up new market perspectives and can lead to a competitive advantage for companies embracing this cutting-edge technology. Wide-scale adoption requires collaborative efforts among manufacturers, institutions, and consumers to ensure a smooth transition toward a more sustainable tanning future. For more information, please contact our laboratory directly at, or one of our sales consultants at