Whatever type or technology—vegetable, mineral, chrome-free, metal-free—tanning involves a significant use of chemicals, water and energy, and therefore needs to be closely assessed.
Fundamental: environmental management
Environmental management is key to a sustainable approach in leather.
The amount of water used, the active chemicals entailed in the process, the wastewater treatment, the type and consumption of energy, waste management, ISO 14001, LWG and ICEC certifications are all elements that can help analyze performance. They provide a solid basis for developing a roadmap for continuous improvement.
In Europe, REACH, Persistent Organic Pollutants, Biocides and the Water-Framework Directive already provide a basic framework for chemical substances.
The circular route
New tanning technologies offer solutions with reduced impact, while retaining the robustness of older-generation methods, and result in convincing handles and aesthetics.
In a circular approach, tannins can derive from plant co-products, such as olive leaves, rhubarb roots, grape must or beer brewing residues, as is the case at Olivenleder, Deepmello and Ictyos. In these instances, the leather industry is drawing on its life-cycle approach to recycling, exploiting not just the skins but also plant-based active ingredients from other industries. Also being particularly examined are formulations that can attain handles, color ranges and resistance matching that of chrome.
To continue to broaden the circularity of inputs, Sciarada, through Evolo, has developed a process recycling production waste from chrome-tanning, transformed into a liquid solution. This technology is even more unique as its processes have been totally revised to reduce the number of required steps, to minimize impacts across the entire value chain.
New generation tanning agents
Formulations free of chromium and glutaraldehyde have a head start on the threshold revisions required by Reach, expected to come into effect in the next few years. These formulations are already free of these potentially risky components.
Aluminum, silica and oxygen make up Nera Tanning’s Zeology® tanning process, which is ZDHC (Zero Discharge of Hazardous Chemicals) compliant and Cradle to Cradle Platinum certified, offering a compelling alternative to chrome.
Silvateam’s Ecotan® mixed tanning, also Cradle to Cradle certified and developed using vegetal tannins and biopolymers, gives leather a unique suppleness and a color intensity previously difficult to obtain using plant-based products. An additional advantage is that both the leather obtained and its production waste can be recovered and used as a biological fertilizer, through partnerships with tanneries and dedicated recycling and recovery units.