The attention of the market today is focused on the search for alternative solutions to traditional tanning processes such as chrome tanning, other mineral concepts and vegetable tanning. But I would like to say a few words about the tanning processes that today cover almost 100% of the global production: It can be said that vegetable tanning has a history of millennia and can be considered the first metal-free tanning process. The chrome tanning is more recent but in little more than one century it has had the success and the diffusion that we all know, due to product features and the high versatility of the articles, properties that still today are not achievable with alternative metal free tanning systems.
Furthermore, considering a process based LCA, the impacts of chrome and vegetable tanning processes on the environment and on humans are now known, while there is little information and experience on the environmental impact related to the application of new tanning molecules, proposed in the last years by the market, for which no studies of toxicity and environmental impact are available and therefore no information regarding the possible repercussions on humans in the long term.
With regards to the alternatives of these two tanning processes, the tanning companies that have developed industrial processes for the production of wet white articles, through the use of glutaraldehyde and synthetic tannins, have been on the market for over 30 years and represent a small slice of the world leather market. This implied the impossibility of being able to conduct a reliable environmental assessment, since the wastewater impact of these companies during the depuration phase has a considerable dilution effect considering the quantity of wastewater coming from tanning companies that carry out chrome and/or vegetable tanning.
It was only a few months ago that news of the increase in wet white production put the purification process in difficulty, with significant repercussions on the environment and productivity. Perhaps it is not clear to everyone that the tanning process begins with the purchase of hides and skins and ends with water purification and sludge disposal. In 2020 it is incomprehensible to me how one can think exclusively of the finished product without taking into consideration the consequences that you may have in the purification phase.
With regard to the new synthetic tanning products, we must be very careful about what is proposed to avoid short-term repercussions both from an environmental point of view and from that of safety and safeguarding human health. In this regard, I would like to give an example of a current problem, namely perfluorinated compounds (PFOS, PFOA, etc.). These molecules were discovered in the early 1900s and within a few years had a wide-ranging industrial application (non-stick products, leather, fabrics, papers, detergents, etc.) without taking into consideration any environmental and toxicological impacts. Today they are in the spotlight and the eyes of all the damage they have caused and still are causing to the environment, with probable repercussions also on mankind.
These molecules, which are difficult to destroy and degrade, are persistent pollutants, which accumulate in water, in soils, and do therefore easily enter the food chain with consequent repercussions on human health. I reported this example to say that if we want to consider ourselves environmentalists and attentive to the health of human beings, we must not repeat the mistakes of the past, introducing molecules that do not have a well-established scientific literature behind them and above all information that can allow a feasibility assessment both from a technological, environmental and toxicological point of view.
Historical data and research tell us that chrome and/or vegetable tanned leather can be managed from the cradle to the grave, that is we know the problems that can arise on the finished product very well so that wastewater management processes allowing the recovery, enhancement and reuse of chrome and sludge have been developed. Today, research has shown that it is possible to recover the proteinaceous substance and chromium even from discarded chrome-finished leather, so that in the near future it is possible to close the circle linked to the production of the leather in a circular economy perspective.
Having said this, I believe it is right to look for alternative tanning products. Innovation and progress are fundamental for all industries, however the research in this sector must always be directed towards a path that leads to the right compromise between products and environmental and toxicological impact. The spasmodic search for metal-free products without a proper evaluation of the process is extremely dangerous for mankind and the environment and one cannot hide behind the slogan “we want to protect the environment”, which then turns out to occur only for advertising purposes to win potential customers especially in the most youthful segments.
I conclude by saying that today, leaving out vegetable tanning, there is no valid alternative to the chrome tanning process, both from a product and environmental and toxicological point of view. We avoid confusion and above all we treasure past experiences so as not to always make the same mistakes.