Environmental footprint

Fact versus Fiction: Exploring the Real Impact of Leather

Why is leather’s carbon footprint considered so high? What role does livestock farming play in this equation? Here are the key takeaways to better understand where leather stands in the pursuit of ecological design.

Calculating the environmental footprint of consumer goods is now a must to evaluate the impact of production and product usage on the environment, notably with regards to global warming (evidenced by the carbon footprint)—and to prepare for the upcoming European regulations currently being drafted to decarbonize value chains and impose the disclosure of product impact to consumers. In this calculation, we tend to set finished products against each other. Leather, despite its inherently high-spec mechanical property value and processability, is sometimes condemned for having a higher carbon footprint than other pliable materials positioning themselves as competitors (when scaled per equivalent surface area). Because ruminant livestock farming generates significant greenhouse gas emissions, leather has been penalized for being intrinsically linked to agriculture. The current legislation for carbon footprint allocations certifies that only a fraction of these emissions comes from hides and leather: about 3.5% for cattle and 1.6% for sheep and goats. Consequently, it is livestock farming which contributes 70–80% of the carbon footprint for 1 m² of leather.

Keep in mind, animals are primarily raised for the food industry (meat and milk), not for their hides, so the skins are in fact a by-product of this core activity, of which only a small fraction is repurposed by tanners into a versatile material, ready for use across numerous applications and product categories. Which is what current impact assessment models do not consider. In this equation, animal hides remain a subject of debate: should they be considered a co-product with a specific carbon emission quota, or a repurposed by-product of food industry waste, that should therefore not carry the environmental burden of livestock farming? The latter hypothesis, being the position currently defended by industry representatives, including the Confederation of National Associations of Tanners and Dressers of the European Community (COTANCE). Don’t forget leather’s intrinsic qualities, its renewable nature (regenerates over a short time scale) and bio-based origins (made from biomass), these inherent characteristics are not factored into current models and therefore are not calculated in ecological footprint coefficients.

In this mad rush to compare products, the functional unit, i.e., the measure of the intended service or function of a product (duration of use) that should serve as the basis for product comparison is often neglected. It is essential to take both product use and functional unit into account to compare environmental impacts accurately. For example, a pair of shoes used for two years has half the environmental impact of a pair used for only one year. Therefore, the environmental impact of 1 m² of leather carries no weight until it is clear what it will be used for. Provided that a product is solid and well-designed for its intended use, the physical durability of a leather item can be a significant factor in reducing its carbon footprint. The Federation of French Tanners is working hand-in-hand with the CTC to develop testing strategies to quantify this physical durability as objectively as possible in relation to its actual use. Emotional durability is another factor influencing product lifespan, as a user’s attachment to a product can significantly delay its replacement and disposal. Research is underway to find concrete ways to measure this durability factor.

High-Quality Manufacturing in the name of consumer protection and safety.

Tanning, dyes, European norms… French tanneries continue to pioneer new measures while fully complying with the strictest regulatory standards to guarantee that products are safe, durable, and ethically made.

Leather is a versatile material used across many consumer goods categories, including leather goods, footwear, apparel, and furniture. Its unique properties: durability, its inherent beauty, and exquisite feel are achieved through chemical operations that employ tanning agents, fatliquoring treatments, and dyes. To ensure chemical safety for both consumer and the Planet, French tanneries rigorously adhere to the strictest European and international chemical safety regulations for consumer goods.

Compliance with European and International Regulatory Requirements.

REACh, is the main EU law to protect human health and the environment from the risks that can be posed by chemicals. All French tanneries are subjected to REACh regulations, which set out conditions to manufacturers of raw material and fast-moving consumer goods, in which certain substances, when deemed hazardous or unsafe — can be restricted or entirely banned in the manufacture, sale, or use of chemicals, mixtures or finished articles. REACh is currently one of the most comprehensive and stringent chemical safety regulations in the world. French tanneries strictly adhere to its guidelines by adapting manufacturing processes as required and collaborating with chemical suppliers to ensure only compliant formulations are used. Accredited laboratory testing is a key part of compliance, and French tanneries carry out scientific testing regularly to certify that their leather meets all standards.
Furthermore, as leather products are exported worldwide, French tanneries must also comply with specific regulations from their export markets and client portfolios throughout China, Japan, and the United States. French tanners are backed by the CTC, which provides access to accredited labs for testing, inspection, certification services and regulatory monitoring. In addition, at the Federation’s request, a comprehensive database (ICARE) has been developed to track controlled substances across different countries, and is regularly updated.

The Voice of Innovation in the name of Leather Chemical Safety.

In response to stricter regulations and evolving consumer expectations for more virtuous and sustainable products, French tanners continue to innovate their manufacturing playbooks, developing new alternatives to more traditional chemicals( especially in tanning and retanning procedures), Ongoing projects conducted in collaboration with the CTC aim to develop new processes that replace certain more toxic substances with safer alternatives, without compromising the performance or exquisite quality of leather.

Water management plays a key role in leather production.

Driven by both voluntary initiatives and mandatory regulations, tanneries reduce their effluence and optimize their overall water consumption.

In France, the regulatory framework applicable to tanneries is the ICPE (Facilities Classified for Environmental Protection). The monitoring guidelines are defined in the company's official authorization documents issued by the Prefecture, based on the requirements of the French ministerial decree of 2 February 1998 and are therefore regularly inspected by local government authorities. The initial stages of transforming raw hides into leather consist simply of cleaning the hides, removing the non-recoverable organic materials, such as hair, wool, sometimes scales, fat, and flesh residue that were not eliminated during hide prep. These washing procedures generate aqueous effluents loaded with organic matter, to which are added highly chemical aqueous effluents from the products used during the tanning process to preserve, tan, dye, and nourish the hides.

These pollutant-loaded effluents are systematically treated either via on-site tannery wastewater treatment plants or in municipal treatment plants, in partnership with local authorities. Treatment involves several standard steps, including screening, de-oiling, and other physical, chemical and biological processes, ultimately to achieve the discharged water quality required under ICPE regulations. As a result, all extracted water is fully discharged into nature post treatment. Regarding water management, many French tanneries have also set up voluntary environmental management guidelines, powered by international standards (such as ISO 14001) or by recognized sector-specific labels (such as the LWG certification), demonstrating efficient water management throughout operational procedures, including end-of-line treatments.

Up against climate change challenges, French tanneries, like other water-dependent industries, are sometimes exposed to the risk of water shortage or even to usage restrictions imposed by public authorities during severe droughts. For this reason, French tanneries are pulling out all the stops to reduce water consumption via more water-friendly processing operations, or by using more high-performance industrial equipment, and by treating and internally recycling certain effluents, allowing water to be reused before being released into the environment.

Prevention and monitoring to ensure workplace safety and compliance with regulations on the use of chemical agents.

A highly rigid French and European framework protects both workshop teams and the end consumer.

The tannery, the leather processing actor which transforms and purifies raw hides into finished leather, requires the use of specific chemical products to clean, de-grease, tan, dye, and nourish the hides. Product selection criteria follow a strict protocol and necessitate preventive measures to eliminate or minimize worker exposure to chemical agents in accordance with French labor laws. French tanneries that comply with these regulations have set up risk prevention strategies, including strict collective protective measures (rules for product storage and use, containment conditions in case of leaks, local exhaust ventilation, gas detectors, etc.) but also personal protective equipment for workers, guaranteeing safety on the job in high-risk zones.

European regulations governing the use of chemical substances, notably the CLP Regulation on chemical classification, packaging and labeling and the REACh Regulation banning the use of certain substances in European industrial processes, provide tanners with a clear framework on which chemicals can be used, their characteristics, and safe operating procedure methods. This framework allows tanneries to implement the required protection measures for their employees. This framework is reinforced by the DREAL (the prefecture’s department responsible for classified facilities under environmental protection regulations) and by labor inspection authority visits, ensuring both environmental and occupational compliance in all tanneries.

Additionally, open-access guidelines and tools developed by the CTC (upon request of the Federation), are available to tanners to centralize safety data protocols and facilitate the assessment and prevention of chemical risks on their sites. Lastly, ongoing and recurring employee training on best practices and chemical risks is a crucial preventative measure. The Federation is fully committed to this goal by including safety and risk prevention in its professional qualification certificates, while the CTC proposes targeted online training modules around health and safety.

Leather, a Renewable/Bio-Based Material

Derived as a food industry co-product, leather remains a fully traceable, naturally bio-based material. Its intrinsic qualities go way beyond emerging materials, which are frequently promoted as more durable, efficient, or eco-friendly.

Choosing the right material is a foundational step in product design, it determines the performance and efficiency of the final good and influences the consumer decision-making process. The recent boom of so-called emerging “alternative” materials on the market, that are often billed as being more high performance, more durable, and more environmentally friendly than traditional materials like leather (the term ‘leather’ is protected by French Legislation Decree No 2010-29), and which also claim to equal leather’s exceptional qualities of comfort, durability, and exquisite feel.

One must never forget leather’s natural characteristics, which unlike fossil-fuel derived materials, is a renewable and natural material made from the raw material of animal hide, which is able to regenerate within a relatively short timeframe as part of a natural life cycle. Unlike non-renewable materials, renewable materials come from living resources (plant or animal) that can be reproduced or cultivated sustainably. Furthermore, the animal hide used to make leather is a co-product of the food industry, since animals are primarily bred for milk and meat production. Leather manufacturing is by its very nature, a millennia old industry rooted in the valorization and repurposing of a co-product.
Genuine leather has another major quality: it is bio-sourced, once again testifying to its renewable nature. Backed by science, a look at the bio-sourced content data on leather establishes this scientifically: results show that leather contains between 65% to 100% of bio-based carbon content, depending on the specific processing method.

At the request of upstream French leather sector players, (including French tanners), a one-of-a-kind skin and hide traceability system has been developed. Through embedded digital laser markings, the origin of calfskins can be tracked from the animal’s birth to the tanned hide stage. Beyond monitoring the environmental impact of the supply chain, this traceability allows for the continuous upgrade of leather skin quality by taking animal welfare into account and securing the processing and preservation of the hide. This traceability guarantees that these leathers meet the requirements of the new European regulation on imported deforestation (EUDR: European Union Deforestation Regulation).

In accordance with the Washington Convention on International Trade in Endangered Species of Wild Fauna and Flora, exotic hides (another French point of distinction) have been traceable for some time now, right up to the commercialization of the finished product. By adhering to this convention, the leather sector has contributed to increasing crocodilian populations; a win-win for both biodiversity and the leather industry.

Valorization of tannery waste

Only the dermis from animal hides is processed into leather by the tanner. All other tissue layers and eliminated matter during the process are considered manufacturing by-products, each offering a varying potential for valorization. This refers to:

• Waste from “River” operations (wet work): hair, wool, sometimes scales, fat, portions of flesh and skin not removed by the slaughterhouse, and which have no intrinsic value for the tanner. This organic waste constitutes the largest volume of debris generated by the tannery.
• Post-tanning leather waste: scraps and leather dust resulting from operations such as splitting and shaving to achieve desired thickness, post-tanning leather sampling and sanding.
• Wastewater treatment sludge: consecutive residues from the treatment of aqueous effluents, primarily consisting of organic and moist mineral matter.

Some “wet work” waste already has tried-and-tested valorization options, much like in the food industry. Animal fats are used as raw material for tallow production, which is then used in oleo chemistry or converted into biofuels. Untanned hide waste can be used as a base for technical gelatin production. Wool or hair are sometimes composted to increase the nitrogen content of compost used in agriculture.

The valorization of leather waste depends on the tanning method used. Tanned leather waste (vegetable tannins) can be used as a base for reconstituted materials, such as recycled bonded leather, or for energy recovery, as leather has a relatively high calorific value. Leather tanned with mineral-based agents (chrome, aluminum, titanium, etc.) is more difficult to valorize due to the presence of metals. However, in Europe, there are industrial facilities that can recover such waste to repurpose into organic fertilizer or to produce retanning agents. Some of this waste is still destined for incineration or disposal in landfills.

According to its composition, sludge from tannery wastewater treatment plants can be sent to a composting facility, to an anaerobic digestion plant, or applied directly to agricultural land. Such land application must be carried out according to a spreading plan, with strict monitoring of sludge composition.

Additionally, to optimize leather waste recovery and valorization, particularly for mineral-tanned leather—the Federation has asked the CTC to find “de-tanning” leather solutions and strategies to remove proteins from tanning agents, which pave the way for highly promising future outcomes

The CTC, in collaboration with the Federation, is also exploring new “metal-free” tanning processes, which could open the door to an easier recovery and valorization of leather waste. CTC, in partnership with the University of Montpellier, has filed for a tanning patent using a silica-based agent and has established an industrial chair to commercialize this technology.

Many other innovative initiatives are now underway.