Metal or metal-free? Let us avoid any misunderstandings: chrome tanning is still the cheapest, safest and efficient processing system in the world, but the market’s drive towards alternative systems is unstoppable and deserves to be followed carefully. The discussion is taking place also because there are no magical solutions, every system currently available has advantages and disadvantages. “It is true, chrome has an efficiency of its own, unparalleled up to now, but a part of the market is moving in a different direction and we tanners must not be afraid of exploring new avenues”, says Roberto Mariano Mecenero, AICC president and a partner of the Dani tannery; for years involved in sustainability themes, also promoting important research projects such as the Green Life project. “At Dani – says Mecenero – we have a tannery dedicated to the production of metal-free leathers destined for the automotive market, because there are some brands that accept only metal-free leather for the interiors of their cars”. But, as is already known, it is not only the automotive industry to push towards metal-free leather. Fashion brands too have for a long time been urging their suppliers to change their production processes, although, for the record, we must say that we found out that a famous brand has recently taken a step backwards with regard to its previous statements and is waiting for more certain information on the real sustainability of the production processes replacing chrome. The need to develop metal-free tanning systems is becoming more and more of a necessity not only from the environmental point of view, but also from the economic point of view.
As concepts such as green economy and circular economy spread, those products guaranteeing to the final consumer a low environmental impact through all the phases of the life cycle are becoming more and more attractive. Recently, there has been an increase on the market in the dissemination of leathers tanned with alternative systems, which are marketed with different names such as wet-white, chrome-free, metal-free, and which have sometimes given a hard time to the local purification systems based on chrome processing methods. Even though we know that the demand for metal-free leather is sometimes due only to marketing laws, it is worth asking ourselves a few questions.
Nowadays, which is the tanning system with the least environmental impact, which one produces less waste, which one consumes fewer resources?
Experts have no doubts. The decision to switch to metal-free leather “does not create any advantages, neither for the final consumer nor for the workers involved in the production process”, says professor Maurizio Masi, director of the Department of Chemistry, Materials and Chemical Engineering “Giulio Natta” at the Polytechnic of Milan. “Trivalent chrome tanning makes it possible to obtain an excellent product in terms of quality, from all points of view, from the tactile feel to mechanical properties, from resistance to allergometric compatibility. Possible alternatives could cause more problems than advantages”, says professor Masi.
UNIC – Italian Tanneries Association sees things the same way: “It is necessary to shed light on the misunderstandings caused by the terminology and by marketing, and to tell a different story. If today 85% of the leather produced worldwide is chrome-tanned, it is due to the fact that extremely high levels of performance have been reached both environmentally and economically – according to Fulvia Bacchi, the general director of the tanners’ association, as she stated in a recent editorial published in the magazine of the Stazione Sperimentale Pelli-SSIP (Italian Research Leather Institute) – Purification plants are able to dispose of the residue contained in waste waters and, if anything, problems increase with the use of products that are an alternative to chrome, since they are more difficult to be disposed of”.
But the sector needs proven scientific truths in order to counter the market’s pressures. For these reasons, UNIC itself has launched a project in order to compare the impact of chrome and chrome-free tanning. A project promoted in collaboration with SSIP, purification companies, tanneries, chemists and universities, among which The Polytechnic of Milan and the Bocconi University. It is an extensive study with the purpose of understanding which tanning system is the most sustainable (we also talk about this in the following interview with Elisabetta Scaglia of UNIC).
Some studies have already been carried out. Biagio Naviglio, in charge of R&S at the SSIP-Stazione Sperimentale Pelli, the sector’s main research institute in Italy, says that several studies have been carried out that have compared three different tanning systems: wet-white, chrome and vegetable: “Currently chrome tanning is still the most advantageous system from all standpoints. Apart from vegetable tanning, the other processes still have many uncertainties both in terms of purification and in terms of the possibility of re-using waste; these uncertainties must be analyzed better”, says Naviglio.
Therefore, as we were saying, currently chrome tanning remains the best option, but the push towards a more and more sustainable economy imposes continuing to study new possibilities and alternative solutions daily, in order to replace the traditional methods. That is why chemical companies and tanneries are at work on a daily basis in order to explore new avenues. The search for organic tanning agents and systems with a lower and lower impact is fully going on.