Human beings had been using leather since the dawn of civilization. Historical references of leather tanning date back to 5000 (B.C.). Throughout time actual leather tanning process used vegetable tanning. Until the end of the 19th Century, when the use of chromium (III) to tan leather was discovered. Though carcinogenic, unlike eco leather, chrome tanning reduced the time to tan a cowhide into 1 day. Thus, this process became very popular for the mass production of leather. Throughout the next century until this era.
That is till this 21st century. People are now more socially and environmentally conscious. Started caring for not just the product but also wanted to make sure they were not harming any human or animal. Neither harming their natural habitat while making it. This led to a realization, that is \”the old ways were the gold ways”. The ancient vegetable tanning process posed less threat to health and the environment. Thus, came the concept of Eco-Leather.
But one issue still left unaddressed. The tanning agent used in vegetable tanning is cedar oil, alum and (the most popular) tannin. These agents are extracts from tree barks and leaves. Pine, cypress, chestnut, oak, redoul, tanoak, hemlock, quebracho, mangrove, wattle, cherry plum tree. All have these extracts. This sounds like a lot of tree-cutting, doesn\’t it? Hence to save humanity, the animal kingdom and plant kingdom all at the same time. I introduce to you the most eco-friendliest genuine leather that there can be: ECOLOGICAL LEATHER.
But before I go in details about ecological leather. You need to be very clear about 2 things before you decide if you want eco-leather in your leather accessories or not.
- What eco-leather really is?
- Why the traditional tanning processes are not very eco-friendly?
Understanding Eco Leather
Eco-Leather is actually a way of thinking, not just a product. Eco-leather is a green answer to the important need to protect the planet, its resources and inhabitants. It is the mindset to recycle, reuse, reduce waste or detoxicating the value chain of leather. For example,
- Recycled leather from old jackets, car seats or sofas. That would otherwise end up in a landfill. So these are eco-leather.
- Leather that comes from organically raised cattle or sustainable fishing is eco-leather. Killing animal solely for its skin, the leather from that skin would not be eco-leather.
- Leather is a natural resource in itself. As long as the rate of consumption is equal to the rate of replenishment, it is an Eco Leather.
And finally, the leather that did not give out toxic chemicals in the process of its making and distribution. That is also eco-leather.
So remember to repair your leather boots next time it gets damaged. Henceforth, you will be an eco-leather user.
Impacts of traditional tanning
Tanning is a mandatory procedure to make leather usable. Without tanning, leather will decay before use. Please note that there is no 100% eco-friendly way to tan leather in this era. Maybe the closest way could be to tan leather with urine and dog faeces. Which is actually an ancient way of tanning leather. But in that case, you will have to isolate a group of people from the rest of the world. There won’t be enough shoes for everyone. Let alone jackets and luxury handbags. No one wants that. There is no natural process to stop natural decomposition. Until we find the fountain of life. And I doubt if we will be using that liquid to tan leather!! The traditional tanning process and its effects are as follows.
1. Chrome tanning
This is the most widely used tanning process in the world currently. Chrome salt like chromium sulfate is used to stop hide decay. Chromium (III) is harmless and found in nature. It is a necessary nutrient for the human body and plants as well. But in the tanning process, the Chromium (III) gets oxidized into Chromium (VI). Due to high level of pH.
Chromium (VI) ion is carcinogenic. It’s accused to be one of the main reasons for the carcinogenic impact on workers of the tanneries. Again Chromium-tanned leather contains 4-5% of chromium for the treatment process. This hexavalent chromium produces allergic reactions and causes dry, cracked and scaly skin. It creates “chrome-hole”, that does not go away.
The bi-product of this tanning process also contain chromium ion and metal ions (from metal salts used in the process). If released in the environment untreated, it contaminates water bodies and vegetation. Eventually affects other life forms including human beings.
2. Vegetable tanning
Vegetable tanning (also a type of eco leather) is the actual tanning process. This is what people had been practicing from ancient times. With the rise of chrome tanning, vegetable tanning lost its significance. Vegetable tanning is a time-consuming process. Significant efficiency loss in mass manufacturing. Near impossible to meet the rising demand for leather goods.
In vegetable tanning hides are immersed in liquor made from an infusion of ground tree bark, twigs, leaves and water. Use of tannin (a class of polyphenol astringent chemicals) is more common these days. This suspension is then tumbled in big drums till tanning is complete. Most widely used tanning materials are the barks of oak, hemlock, mangrove, mallet (a kind of eucalyptus), birch, larch and pine. And extracts from chestnut wood, mimosa, quebracho (a South American tree), myrobalans (the fruit of an Indian tree), valonia (the acorn-cup of Levantine oak) and sumach leaves and twigs. The choice of tanning material determines the colour, density, flexibility and cuttability. It also determines how long will it take for the tanning.
Many basic operations involved in vegetable tanning and chrome tanning are similar. Sequences might be different from chrome tanning. And there are some finishing operations in the vegetable tanning process. But this process does not incur any hazardous health issues like chrome. The only setback is for mass production of vegetable leather we end up chopping down a lot of trees. Either when using the tree barks directly or due to bulk production of the chemicals extracts from the trees.
3. Aldehyde Tanning
Aldehyde tanning produces what we call “chrome-free” leather, also known as \”wet white\”. Common uses of this leather are in automobile, upholstery, garments, and shoe upper. It is often used in baby shoes as well. Formaldehyde is one of the chemicals in the aldehyde group. This is the chemical in this process which stops leather decay.
Formaldehyde is highly toxic to all animals. Ingestion of as little as 30 mL (1 oz.) with 37% formaldehyde can cause death. And it can also cause cancer (like chromium). Leather for general use should not contain any more than 200ppm of formaldehyde. That is according to BLC Leather Technology Center, UK. In case you need to know \”ppm\” is same as \”mg/L\”. If the item is in direct skin contact this should be 75ppm, and 20ppm for items used by babies (<36 months).
Some tanners may use glutaraldehyde instead of formaldehyde. It is a less toxic aldehyde. Glutaraldehyde does not contain formaldehyde. Nor does it release formaldehyde, even after prolonged storage under adverse conditions. Exposure to formaldehyde can cause allergic contact dermatitis. Nothing of sort occurs on glutaraldehyde exposure.
What is the different between Ecological Leather and any other eco leather?
Ecological leather tanning has brought about a revolution in the tanning process. This is the latest tanning process to manufacture high-quality leather. It is very eco-friendly and has very little impact on health and the environment. Ecological leather is processed in tanneries with their on ETP (Effluent Treatment Plant). Or which falls under the CETP (Central Effluent Treatment Plant) of Bangladesh. This treats liquid bi-product from various unwanted chemicals. Acids, dyes and colour, all neutralized before releasing to the environment.
The process uses very eco-friendly chemicals from sustainable suppliers. Some would be LanXess, Pulcra Chemicals, Schill+Seilacher, Stahl and Vismon. There is no use of metal salts. The use of aldehyde is very low. Modified aldehydes used to reduce harmful effects. A very low quantity of formic acid used and neutralized afterwards. The ecological leather produces is also free from alkylphenol ethoxylates and nonylphenol ethoxylates.
The mother component of the ecological leather tanning process is Syntan. This synthetic tanning agent is made through the condensation of formaldehyde with the sulphonic acids of phenol and naphthalene. Syntan has the same capability to convert animal protein hide to a permanent substance as other tanning materials i.e. it stops decay. If you don\’t want your brain to burst open due to chemical reaction from too much chemistry. Then move to the last section.
Features
Ecological leather does not cause itching. It is also preferred to use in the products of babies and diabetic patients. Ecological leather is softer than usual leather due to the use of polyurethane. Using waterproof fat and lecithin fat can soften it further. And phosphoric ester to make it even softer. Touching leather goods from Ecological leather feels very smooth. You will feel comfort, to the max. These are also very easy to clean and wash as the leather has a very fine surface. Ecological leather gives a unique non-uniform colouring and beautiful surface texture.
Sustainability
Ecological leather tanning is more sustainable than any other tanning process. The traditional tanning process causes a huge amount of leather wastes. This new process has brought about a change in reducing the amount of leather waste. Ecological leather tanning requires less water than a conventional tanning process. The Ecological tanned leather is completely non-toxic due to the use of syntans. Also, it is way easier to remove synthetic particles from water than other ions and salts. Hence 95% of the water used can be purified or recycled.
Drawbacks
The cost of production exceeds the price of raw hides and skin used in ecological leather tanning. The chemicals used, like syntans, are more expensive than chrome slats. The price remains high whether low graded or high graded hide used. Hence only high graded raw hides are used for ecological tanning. To capture the niche luxury market. Capturing the mass market is not feasible yet.
The process required close monitoring. So engineers are constantly engaged. The damp atmosphere and wet conditions produce the wrong output. Hence tanneries need to be well maintained to produce ecological leather. The time of processing is shorter than conventional tanning. But the leather needs to be hanged for a longer period than usual. For these reasons, the price and delivery time of ecological leather is pretty high.
Conclusion
Demand for eco leather is rising globally. Ecological leather is already very popular in countries like Japan and Italy. Other developed counties are going to follow through the adoption. A safe and environment-friendly leather that needs to reach the mass. And eventually, it will.
The core concept of sustainability is very simple. \”Meeting the needs of this generation without compromising the needs of future generations\”. Working for the future is so much easier when present is ensured. Not the same when your present is in crisis. People giving sustainable effort in a developed country and an underdeveloped country is not the same. A group of consumers or companies from the developed country can easily boycott a factory. Because it is damaging the environment of Bangladesh. But for that factory, the economic implication to make that change is same as going out of business. This is true for many small and medium factories. And many SMEs in Bangladesh did go out of business in this way. With it, thousands of workers went jobless and homeless.
The will to save the environment is no doubt a noble intent. But we should not forget that sustainability is not all about saving the environment. Sustainable development encompasses social and economic development too. So it is also your moral obligation that when you buy, you buy from those in need. And help them in the process. The leather industry of this economically deprived country (Bangladesh) needs your support. Please overlook some of our shortcomings and help us grow. Manufacture your ecological leather or any other type of leather & leather goods, that you are working on, from Bangladesh
