Measuring and reducing the leather footprint

Measuring and reducing the leather footprint

There has been a long and complicated debate on how to measure the environmental impact of leather production. Even in recent articles, where leather is compared to other materials, the topic of its resourcing comes up as a divisive aspect. Finding a way to define, measure accurately and analyze the environmental impact of leather has been a significant challenge, but the approval of the Product Environmental Footprint Category Rules (PEFCR) by the EU’s Environmental Footprint Steering Committee is a defining step forward.

It’s important to note that up to 16 impact categories make up the environmental footprint of a product. The impact on climate change, or carbon footprint of leather, is just one of them. This is often overlooked in public perception. Improving thus a tannery’s environmental performance means also reducing water consumption and optimizing chemical use, implementing efficient waste and emission management and some other aspects. Major advancements have been made in all these areas. Today, the PEFCR for leather finally offers a comprehensive method of measuring its impact.

Animal rearing, leather, and product impact

The big question about the footprint of leather has always been about the inclusion or exclusion of animal rearing, as it significantly affects the calculation. The major part of the environmental footprint of leather, if included, would be in animal rearing. This would hide the actual impact of leather-making, which is what makes the difference between one or the other tanner. This is why, the system boundaries, acknowledged by the PCR - CEN Standard EN 16887, set the start of the lifecycle of leather at the slaughterhouse, where the hide or skin is actually obtained. The reason is that skins and hides are a non-determining by-product from the food industry. This means that no animal will be slaughtered for its hide or skin and that the amount of available leather will always be determined by meat consumption (hence non-determining). This doesn’t change the fact that the footprint of animal rearing is an important factor, as it will continue to affect public perception and hence the availability of leather.

This is an important question, and the PEFCR’s close-to-zero-allocation of impact on skins and hides provides already a reasonable basis for assessing the environmental footprint of leather. Leather manufacturing may depend on the food industry, but the other way around this is not so. In other words, the prime reason for cattle rearing in the agricultural sector is food, not leather. This form of ascribing process impact to the main product is not a novelty but based on consequential LCA methodologies, which distinguish between products and co-products on the one hand, and by-products and waste, on the other hand. If the process intends to realize product A, the impact cannot be ascribed to a by-product B, which is an unavoidable residue (or wastes).

Life cycle assessment: towards a methodology for impact assessment

The PEFCR opens the way for methodically assessing the impact of leather on the environment, with regard to global warming, acidification, ozone depletion, resource depletion, eutrophication, etc. The PEF method is based on a so-called attributional Life Cycle Assessment (LCA) methodology, where consequential aspects are not yet recognized. This slows down the attribution of 0-allocation for hides and skins. The current allocation rules are, however, not immutable and there are chances for correcting the EU tool to measure the impact of leather and identify opportunities for improvement.

Leather_product_carbon_footprint

The real footprint

To understand why LCA is essential, it's important to realize it's not only a measuring tool. It offers a fact-based and scientific approach towards environmental impact. The PEFCR for leather enables tanners to look at the entire process and how it affects various ecological categories, which are often simplified by talking about the carbon footprint alone. It necessitates a qualitative collection of data on chemicals, water and energy, but also air, waste, and the end of product life itself.

Next steps taken by implementing PEF

Already, a lot of research has been conducted to find key process steps that can be improved in leather production. The dehairing of animal hides, which is one of the first steps a skin or hide undergoes, was traditionally done using chemicals that significantly impacted the eco-toxicity of freshwater and marine waters when disposed of. The beamhouse phase, as this step is called, could use up to 70% of all the water used in the leather making process and could be a source of water eutrophication if not controlled.

After identification of this issue, alternatives have been introduced, such as enzymes for the cleaning of the hides. The hair-save method has been in use as the best available technology for at least 20 years. Measurement of the impact of enzymes compared to chemicals through an LCA method shows conclusively that the enzymes have a reduced impact. Particularly, when the waste material is also composted. The PEFCR helps to identify key points of improvement in the process that will help reduce the footprint even further in the future.

Towards an Environmental Product Declaration

For automotive producers, the PEF opens new possibilities in consumer transparency. The only downside, for now, is that this methodology doesn’t allow for a direct comparison between different products (e.g., leather versus plastics). Apart from the obvious benefit of having data on various interior options, it also enables communicating to consumers and business partners with clarity on the leather’s environmental impact. In the future, this is likely to become a legal obligation. Such a development would enable green initiatives to be captured in results and data, instead of mere greenwashing statements.

[Article updated with kind corrections from COTANCE in May 2020]