Leather and the environment

We are currently in Hong Kong attending a few conferences and trade shows on which we will report in the coming days, so stay tuned. Last Tuesday we kicked off our trip with the "Leather and the Environment" seminar organized by the BLC Leather Technology Center from Northhampton (UK).

Calculating the costs of natural services

One of the highlights for us was the lecture by Reiner Hengstmann, Global Director of the PUMA.Safe program through which Puma aims to reduce its own carbon footprint and raise work and production standards globally. He presented the company's first Environ-mental Profit and Loss Account (E P&L) for the year 2010.
An E P&L is a profit and loss account that measures the immense value of ecosystem services - such as fresh water, clean air, healthy biodiversity and productive land - to a business, revealing the true costs of a business’s impacts on nature. It showed that if Puma would have had to pay for the ecosystem services their entire supply chain used in 2010, they would have had to report a loss of 145 million euros!
Unfortunately nature does not have a bank account to help replenish its resources, yet Puma made the E P&L to help anyone involved in their supply chain understand the magnitude and importance of their impacts on the environment, so strategic decisions can be made to reduce them most effectively.

 

As you can see in the diagrams the major part of the environmental costs are generated by Puma's footwear division. This is due to a large extent by the amount of leather used. Cattle farming and leather tanning and finishing are the most energy intensive process and some of the most water intensive processes of all the processes in the supply chain. In addition, cattle farming is the most land extensive material used in Puma's products. Hengstmann stated that livestock takes up 30% of all available land and is a major force of deforestation. 

Chrome tanning as the most sustainable alternative

This particular conference was - perhaps obviously - not the place to discuss leather alternatives, yet facts such as these made talking about leather and sustainability feel rather awkward sometimes. However, with leather still being the main material for footwear, improving its sustainability as much as possible is essential and regarding this the conference offered a few surprises to us. 

For instance, a couple of the experts stated that when used in the right way, chrome tanning (with the strict exclusion of the carcinogenic chrome VI) is in fact the most sustainable alternative, even though most people in footwear assume that vegetable tanning is most eco friendly. 

Dr Dietrich Tegtmeyer, leather chemist and vice president of product development and application technologies at Lanxess, explained that chrome can be recycled continually and that chrome tanning requires less retanning substances (leather is usually retanned before it is finished) and fixes the retanning agents very well. Later in the afternoon BLC's Technical Director Dr Victoria Addy mentioned that chrome tanned leather biodegrades quicker than naturally tanned leather.

Her presentation about the necessary 'End of Life' considerations for footwear showed that currently 95% of all footwear waste in the UK - as in most other countries - ends up in a landfill; only 5% is recycled! Yet within the next decade we are running out of landfill space. Usually, leather shoes biodegrade within 25-40 years, but since most landfills are closed off from air and water - to prevent leaching of toxic substances - that process could take decades longer. 

This is why BLC has been researching leather composting: accelerating biodegradation using air, bacteria and/or enzymes and heat. This showed that the process of biodegradation can be sped up to only a few months. However, composting does create CO2 and ammonia and BLC states that the compost still needs to be analyzed for nutrient values and chrome content. 

Chamois and chrome free leather biodegrade most quickly and ironically vegetable tanned leather is in fact the hardest to biodegrade! This is because the tannins in vegetable leather are weakly bound, so they remain active and are capable of interacting with enzymes, reducing their effect and making vegetable leather more resistant to biological degradation. Even though there is still lots of work to be done, research like this could help tanneries develop tannages that make leather easier to biodegrade, especially when composted in a controlled environment. 

For more info about the Leather and the Environment conference, please contact BLC.

You can find Puma's full Environmental Profit and Loss Account for the year 2010 here.