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 various aspects make up the environmental impact of leather. One of the focus points of the PEFCR is the carbon footprint of leather, which excludes some other elements that are often overlooked, both by this method and in public perception. Reducing the tannery footprint, by reducing water and chemical use, efficient waste and emission management are all critical focus areas for tanners, and in which major advancements have been made. Yet, PEFCR finally offers a quantitative method of measuring impact.
Animal rearing, leather, and product impact
The big question about the CO2 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. However, the system boundaries, acknowledged by the PCR - CEN Standard EN 16887, set the start of measurement to start at the slaughterhouse. The reason is that skins and hides are a non-determining co-product from the food industry. This means no animal will be slaughtered for the acquisition of leather as the amount of available leather will always be determined by meat consumption (hence non-determining). This doesn’t change the fact that the carbon footprint of animal rearing will continue to affect public perception where it concerns leather.
This is an important distinction, as the close-to-zero-allocation of impact on skins and hides provides a basis for assessment. 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 previous standards for co-products. If the process intends to realize product A, the impact cannot wholly be ascribed to product B (or wastes).
Life cycle assessment: towards a methodology for impact assessment
The PEFCR opens the way for methodologically assessing the impact of leather on environmental issues. Examples of these are global warming, acidification, ozone depletion, resource depletion, and eutrophication. This method is called Life Cycle Assessment (LCA), which is a cradle to gate approach that helps to quantify leather production data and report on the environmental impact of the processes. LCA is widely used as an industry standard, but now also offers leather manufacturers a tool to measure product impact and identify opportunities for improvement.
The real footprint
To understand why LCA is essential, it's important to realize it's not only a measuring tool. It harmonizes the way the leather industry sets its standards. It offers a fact-based and scientific approach towards environmental impact and not just based on the carbon footprint. LCA 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 hides, chemicals, water and energy, but also air, waste, and the end of product life itself.
Next steps taken by implementing LCA
Already, a lot of research has been conducted where an LCA inventory is used to look closely at leather production to find key process steps that can be improved. The dehairing of animal hides, which is one of the first steps a skin or hide undergoes, was traditionally done using chemicals that significantly impact the eco-toxicity of freshwater and marine waters when disposed. 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 LCA shows conclusively that the enzymes have a more reduced impact. Particularly, when the waste material is also composted. LCA 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 LCA 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 the creation of an Environmental Product Declaration (EPD). Currently, EPD is a voluntary form of providing consumers and business partners with clarity on the product’s environmental impact, yet in the future, this is likely to become a standard. This development would enable green initiatives to be captured in results and data, instead of mere greenwashing statements.