Every stage in the leather supply chain presents a substantial sustainability challenge. Air, water and soil pollution; deforestation; and a wide variety of health and safety risks pose obstacles that the industry is working to overcome. Fortunately, the past few years have proved that the methodology, technology and, increasingly, the willpower exist to ensure a more sustainable future.

Much of the credit for this must go to companies such as Stahl, which was promoting sustainability long before it was fashionable. The Netherlands-based chemicals specialist has long been noteworthy for its work on cleaning up the supply chain by ensuring its commercial partners meet strict sustainability criteria, and hammering home the fact that environmentally friendly, transparent operations offered significant competitive advantages.

The company has also played a leading role in the research and development of innovative technology through the creation of Stahl Centres of Excellence, such as its automotive-focused laboratory in Waalwijk, which opened in September 2015, and through the acquisition of smaller, innovative chemical companies in need of support from a global player.

Products developed in recent years include Stahl EasyWhite Tan, a chrome-free tanning system that can reduce water consumption and chemical usage in processes.

A new way of looking at things

In February this year, Stahl agreed a partnership that could deliver its most significant sustainability breakthrough yet. After nearly 16 months of testing and negotiation, the company became the sole distributer of Probiotics for Leather, a totally biodegradable, all-natural probiotic formulation made by Proviera Biotech. The Kansas-based life sciences company’s products are aimed at the beamhouse phase, in which chemicals are used to clean dirt, blood and fat from the hides, and include degreasing, soaking and wetting agents.

Formulations based on Proviera have been shown to be effective alternatives to the traditional chemical surfactants, enzymes, salts and amines currently used in the beamhouse step of the process, and are based on metabolites derived from a controlled fermentation process that uses probiotic cultures and completely natural raw ingredients.

The metabolites contain carboxyl and hydroxyl groups, which confer high polarity and solubility upon the molecules in the hide. They also contain active radicals that bond with other organic molecules.

Sustainability means different things to different people, but there’s definite movement towards consensus.

The use of probiotics effectively produces a cleaner beamhouse phase, reducing the amount of water and chemicals needed to clean hides, and reducing the demand for chemical and biological oxygen in water treatment plants.

“The challenge is no longer just making leather,” says Marcus Breulmann, Stahl’s technical manager wet-end chemicals. “The question is how to make something that will harm the environment less and be more sustainable.

“Proviera is one piece that fits very well in Stahl’s overall strategy. It fits perfectly into the context of minimising environmental impact in terms of things like the amount and quality of the waste water that is produced.”

Stahl has begun to market the products for the beamhouse phase of the production process; Breulmann is sure that probiotics could also play a significant role in the wet-end and finishing stages of the supply chain, though he is understandably reluctant to commit to a time-frame while research is ongoing.

“I always step far away if someone asks about timelines for development work, as you never know when the work will be ready,” he says. “There are some trials running. I don’t want to go into detail, but it looks very promising. Probiotics lead to completely different views, opening doors to new and different technology.”

One piece of the jigsaw

Proviera Probiotics could have a profound effect on the leather industry. As well as being cleaner than existing options, they carry no significant cost premium, suggesting potential in emerging, as well as developed, markets. Stahl’s Centres of Excellence tailor their research to best suit their locations: fashion in Florence, and automotive in Mexico and Waalwijk, with more to come next year. In all, the company employs more than 1,800 employees at 11 manufacturing sites and 38 application labs in 23 countries.

“Even if we only speak about automotives or upholstery, everyone has slightly different demands and specifications,” says Breulmann. “Some auxiliaries might be allowed in Australia and New Zealand, while others, which may be approved in the US, are not. You have to be close to the market; the Centres of Excellence have very good horizontal communication, so if something comes up that isn’t locally appropriate, it will get moved to wherever the demand exists.”

Stahl’s sustainability effort also brings practical benefits. The firm is part of the UN Global Compact, has formed partnerships with the United Nations Industrial Development Organization (UNIDO), Solidaridad, and, most recently, with industrial development-focused, non-governmental organisation PUM, which is financed by the Dutch Ministry of Foreign Affairs. The partnership works by combining Stahl experts with PUM staff members on the ground in various parts of the developing world for short-term missions. The shared knowledge should lead to improvements in the way companies do business.

“We are working with them on very specific topics in certain regions in which Stahl can offer expertise and help improve the overall environmental situation in specific regions,” says Michael Costello, Stahl’s director of sustainability. “The cooperation with PUM is just one of the many we are working on outside the everyday business of selling chemicals.”

Costello is keen to point out, however, that it’s not just emerging markets that need the help. Many in the industry still fear that adopting sustainable practices could result in decreased competitiveness, but he believes a tipping point has been reached. The pressure to change is now coming from the top of the chain, and eventually companies will have to comply, or fail.

This may well have been helped by initiatives run by groups such as the Zero Discharge of Hazardous Chemicals (ZDHC) Foundation. In December 2015, it published a list of restricted chemicals that it believed should be eliminated from leather and synthetics production in an effort to create an industry standard for hazardous substances.

Stahl is working closely with the foundation, as well as clothing and accessories brands at the top of the chain, to encourage these changes.

“There’s some way to go,” Costello says. “What’s important is that the brands are driving this, and it has an impact on all regions, not just those that are developed, or undeveloped. The good news is that the pressure is really coming.”

Plotting the right course

In order to move in the right direction, the industry must first plot the right course. This will require regular, unhindered dialogue between chemicals companies, tanneries, brands and OEMs on what sustainable practices should look like, and who should take responsibility for what.

Twenty or 30 years ago, this simply never happened, but things have changed for the better. Organisations such as the Leather Working Group, which meets a couple of times a year and counts on members from across the supply chain, aims to “develop and maintain a protocol that assesses the environmental compliance and performance capabilities of tanners”, and promote “sustainable and appropriate environmental business practices”.

This type of initiative, combined with the persistence of companies like Stahl, has set the scene for a uniform approach.

“I see a strong effort from everyone in the industry to start to develop some standards, in particular with regard to the use of restricted substances in the supply chain,” Costello says. “Sustainability means different things to different people, but there’s definite movement towards consensus.”

In Breulmann’s view, the increased cooperation in establishing sustainability goals is indicative of the gradual, widespread acceptance of the new state of play in the leather industry.

Hide is natural waste from meat consumption. Do it right, and you’ll have an excellent product made from waste in a very clean way.

Once it was all about buying the hides, selling the leather and pocketing the money, but now products come with a story that must sit well with increasingly environmentally aware customers.

“Today, it’s not enough if leather just looks nice,” he expands. “Everything must be transparent and state-of-the-art, otherwise you’ll lose business.”

Positive outcome

While the technology is getting better and better, there is always room for improvement. Costello believes that the biggest improvements we are likely to see over the next few years will be in reducing the amount or increasing the quality of water effluent, something that Stahl’s laboratories are looking into.

Breulmann is keen to accentuate the positive, the fact that, if made properly, leather is the right material for a low-waste future.“Leather hides are natural waste from meat consumption. Do it right, and you’ll have an excellent product made from waste in a very clean way.

“This is often forgotten when leather is compared with other materials. We are going the right way. If you see the complete picture, what has happened in the last 15 years is absolutely fantastic.”