The eco leather story
In the strict verbal sense of the definition, the term “eco leather” has no formal meaning. However, there is significant interest in leathers that imply improved environmental performance. So how do we interpret the current situation and understand the issues surrounding the interest in “eco leathers”?
The manufacture of leather does have an environmental impact, in as much as in the manufacturing process not all the inputs end up in the leather. Also when leather is disposed of the product becomes a waste material. What seems to have happened is that the gauge of a leather’s “eco-ness” is measured by the absence of certain restricted chemicals, such as banned azo dyes, PCP, chrome VI, formaldehyde and an increasing list specified by brands; or the method of tannage rather than any consideration of the real environmental impact. This push originated from the automotive sector (where the recycling of automotive parts is regulated in Germany) but more recently by environmental pressure groups, eco labels, high street retailers or those seeking to gain competitive advantage through product positioning.
It is important to judge the relevant importance of all the different aspects so that products can be selected knowledgeably and relevant issues can be explained to customers.
Tackling the issue of tannage first, it can determined from life cycle analysis carried out by Ecobilan S.A (Ref BLC Report 002) that the three main tannages (chrome, vegetable, aldehyde) have very similar environmental impacts as the following extract highlights:
Key findings of the study:
“None of the three tanning technologies under study offers a full environmental advantage over the others when considering all the key criteria that characterise the impact on the environment of these technologies”.
Many people assume that vegetable tanned leather should have a preferred environmental profile, but the evidence does not support this. It should be noted that the whole purpose of tanning is to cross-link the collagen matrix to prevent putrefaction and hence decomposition.
On the other hand, chrome tanned leathers are often assumed to be less desirable because of their mineral content, or wrongly believed to be tanned with the toxic chrome VI salt. Leather today is tanned with inert chrome III and chrome III is essential for normal glucose, protein and fat metabolism and is thus an essential dietary element. This is not to say that chrome tanned leathers do not have end-of-life issues potentially greater than comparative tannages.
The aldehyde tanned leathers meet the needs of the automotive sector and appear to fit a niche within children’s products that need to comply with EN71/3, but they can have handling, effluent treatment and higher energy consumption issues.
If we assume that the different tannage types discussed above have similar impacts we must consider the way the leather is made. Our belief, based on extensive research and industry knowledge, is that environmentally preferred leather can be defined by two key parameters:
A. How the leather is manufactured
B. What inputs are used to manufacture it
Dedicated research has shown that a significant part of the environmental impact of leather is in the manufacturing processes, taking it from a hide to finished leather. In this respect it is the environmental stewardship practice of tanners coupled with chemical selection that should determine how eco friendly a leather is. If we take the model adopted by some of the world’s leading brands that have been working on these issues for the past two years, we can determine the following areas of leather manufacture that have the most significant potential impact:
- Management of restricted substances
- Energy consumption
- Air emissions
- Waste management (hazardous and non hazardous)
- Environmental management systems
- Water consumption
- Control of manufacturing processes
- Effluent treatment
- Chrome management
- Traceability of material
In terms of the selection of inputs for the manufacturing process it is necessary to consider the use of certain materials that could give an improved eco profile to leather. These are elements such as:
- Biodegradable wetting agents for soaking
- Reduced sulphide processing
- Non synthetic or polymeric re-tannage systems
- Natural dyestuffs
- Vegetable oil based fatliquors
- Optimised finishing systems to reduce waste such HVLP or roller coating
- Biodegradable in 12 months or less
In summary, although there is no current definition, these are the key elements we believe should determine an eco leather;
a. Control of leather manufacturing processes
b. Clean technology chemical selection in the process
c. Effective management of restricted substances within the leather
d. A measure of the end of life impact
BLC eco leather rating
BLC operates an eco rating system for leather. Retailers, brands or tanners who are able to meet the requirements of this standard are eligible to use the EcoSure mark.
This mark is operated in conjunction with the Leather Working Group (LWG). To be eligible to use this mark tanneries must have achieved at least a Bronze award in the LWG Tannery Environment Auditing Protocol carried out by BLC and the finished leather on which the mark is to be used must meet the requirements of the audit and testing regime.
The objective of this multi-stakeholder group is to develop and maintain a protocol that assesses the compliance and environmental performance of tanners and promotes sustainable and appropriate environmental business practices within the footwear leather industry.
The group seeks to improve the tanning industry by creating alignment on environmental priorities, bringing visibility to best practices and providing suggested guidelines for continual improvement.
It is the group’s objective to work transparently, involving suppliers, brands, retailers, leading technical experts within the leather industry, NGOs, academic institutions and other stakeholder organisations