Leather is one of humanity’s earliest and most useful inventions. Leather is still used widely today to make clothing and accessories as well as furniture and tools.
Is leather biodegradable and is our use of this material harming the environment? We find out in this article.
What is Leather?
Leather is a material that is made from the skins or hides of animals. The most common hide used to create leather products is sourced from cows, although kangaroo and goatskin leather as well as snakeskin are also options.
These hides are removed from animals and then processed using chemicals to make the leather products we’re familiar with.
Is Leather Biodegradable?
Yes, leather is biodegradable.
Just how easy it is for leather to biodegrade depends on the processes and chemicals used to make it. The problem is that leather is designed to be as durable as possible, and its this durability and strength that increases the time it takes leather to break down.
Any type of leather can also be composted, but the speed of degradation and the environmental impact depends on the tanning chemistry used.
A natural and unprocessed hide is the most biodegradable type of ‘leather’, but hides in this raw state aren’t suitable for consumer goods.
The process used to turn animal hides into leather is known as the tanning process. This tanning process changes the chemistry of leather fibers to make it harder for the enzymes from bacteria and fungi to break them down. This change in composition changes the biodegradability of the material.
How Long Does Leather Take to Biodegrade?
The more processing leather products undergo, the longer it will take them to decompose in the natural environment.
Most leather goods such as handbags, belts and shoes will take around 50 years to completely biodegrade under optimal conditions.
Like all materials, there are three stages of leather biodegradation:
During the first two stages, leather breaks down into smaller components. In the third stage, these components are assimilated as nutrients by microorganisms. Materials that remain at the 1st or 2nd stage are not ultimately biodegradable and persist in the environment, typically as small pieces or scraps.
Compostability is a type of biodegradability. Compostability is the ability of a material to be biodegraded into compost and is relevant to the first two stages of biodegradation. It requires specific environmental conditions where ecological toxicity criteria are applicable.
When a material passes through all three stages of biodegradation it is fully taken up as new biomass which closes the materials’ life cycle.
The Importance of Biodegradable Leather
Ocean plastic pollution or “plastic soup” as we sometimes call it has shown us just how important it is that materials can biodegrade back into the natural environment.
This is a topic that leather manufacturers are becoming more interested in because consumers are increasingly demanding vegan or eco-friendly leather. The leather industry is driving innovation to increase sustainability in the leather production chain, and biodegradability is an important part of this solution.
The end-of-life (bio)degradation of materials depends on the environmental conditions: wet or humid, with or without air and hot or cold. This is important because leather and the products made from it can be found in environments such as landfills, effluent treatment plants, composting units or littered in nature.
Is Leather Eco Friendly?
Most animal hides are obtained as a by-product of the meat industry. This means that the cattle we eat is a valuable resource and one we waste as little as possible of.
Livestock farming is resource intensive and is also a significant contributor to global emissions, so making the process efficient with minimal waste is important.
The other negative environmental factor are the chemicals used to process leather. These chemicals are strong and need to be disposed of carefully which has a further environmental impact.
Leather production isn’t good for the environment, but new technology and processes are continually being introduced to make this industry as sustainable as possible.
A scientific whitepaper found that the tanning process can have a big impact on biodegradability without comprising performance.
Zeolite tanned leather was compared with conventional tanned leather. It was found that Zeo White leather will rapidly biodisintegrate into small pieces if placed into the natural environment. The biodisintegration of Zeo White under industrial composting conditions was shown to form a proper compost within 15 days.
The test demonstrates that the tannage stabilises the leather for use, but in the biosphere, microbes can easily access and use enzymes to disassemble the collagen protein structure.
Leather is biodegradable and compostable to a certain extent. In practical terms, most leather products will remain in the environment for many years after disposal.
There are several new innovations which are addressing this issue which will contribute to improve the sustainability of leather.
Leather is designed to last, so consider selling old leather goods rather than throwing them away. You can look into a local leather recycling programs that are available in your area.