| Leather is a long contested material - hated by | | | | attracted to the speed and efficiency of mineral |
| vegetarians and vegans as an animal byproduct but | | | | tanning - usually discarded without regard to the |
| revered by many as a durable and luxurious material | | | | environment, but the amount of water and power |
| for clothing, furniture, books and more. No matter | | | | used to complete leather tanning are also |
| where you stand on the leather debate, it is certainly | | | | environmentally damaging. |
| true that the tanning industry leaves a lot to be | | | | In September of 2008, Hands On completed a study |
| desired on the environmental front. The main reason | | | | of the tanning industry in Pakistan, one of the largest |
| for this is the tanning process used industry wide. | | | | epicenters of leather tanning in the world. The |
| Although there is now an expanding demand for | | | | environmental challenges included some of the |
| naturally tanned leather, and those products are | | | | following:o Inefficient Water Use - in some cases |
| making their way onto the market, it's worth it to | | | | over three times the estimated amount of water |
| explore the most common tanning processes and | | | | actually needed for the process of rinsing and |
| their environmental impact. | | | | soaking the hides throughout the process.o Polluted |
| Tanning is the process by which animal skin is actually | | | | Waste Water - not only are many factories using |
| turned into leather. In modern tanning, this takes | | | | too much of this valuable resource, but the waste |
| place in multiple stages: | | | | water is merely dumped back into the local |
| 1. Basic Preparation - Preparation begins with treating | | | | environment with little or no treatment to remove |
| the hide with salt, or curing, which removes collagen, | | | | chemical waste.o Solid Waste - Untanned and tanned |
| bacteria and water from the hide to prevent rotting. | | | | solids are also thrown away and fed back into local |
| There are several methods of curing hides including | | | | markets for waste materials. This can be as much |
| brine curing and wet-salting - all techniques occur at a | | | | 12,000 lbs per day from a tannery processing 22,000 |
| low temperature to further reduce chance of | | | | lbs of hide for tanning per day. Many of these waste |
| bacteria. The hides are then rinsed and rehydrated | | | | materials are exposed to chromium which means |
| for the next process. | | | | potential chemical leeching into the local environment |
| 2. Un-hairing - At this point the leather is treated to | | | | and some waste materials are used by industries like |
| remove the hair. Various chemicals can be used in this | | | | glue manufacturers and poultry feed processors - but |
| process, the idea being to break down the hair while | | | | again chromium has been used and can pollute |
| leaving the skin of the hide itself intact. Ultimately a | | | | chicken feed and the chickens sold by those |
| machine is used to remove the hair from the hide. | | | | companies.o Air Emissions - in most tanneries, any |
| 3. The hides are then treated with a combination of | | | | chemicals that are used can cause air pollution - like |
| salt and sulphuric acid to soften it again for | | | | ammonia and hydrogen sulphide, and these tanneries |
| processing. | | | | often use diesel engines and generators to power |
| 4. The tanning itself occurs - and can be | | | | plants and boilers which create CO2 emissions. |
| accomplished in two ways:a. Vegetable Tanning - This | | | | The good news is that new eco-friendly tanneries |
| method involves the use of tannin - from which | | | | are being built - in fact, one is opening up in 2009. |
| Tanning gets its name. Using the barks of various | | | | Understanding the environmental impact of materials |
| trees from which tannin can be extracted, the hide is | | | | that are so often used and sold in the US, like |
| stretched and then soaked in a tannin concentrated | | | | leather, is an important step towards becoming more |
| bath for several weeks. Different concentrations of | | | | environmentally aware, and in choosing companies |
| tannin produce different tanning results.b. Mineral | | | | that support eco-friendly business practices and |
| Tanning - This method uses chemicals and minerals, | | | | materials. |
| primarily chromium sulfate to tan the material in a | | | | For example, there are several shoe companies who |
| similar method to that of the vegetable tanning. This | | | | are using sustainable leather, or who are planning to |
| method is much faster but produces more effluent | | | | purchase leather from environmentally conscious |
| chemical waste. | | | | providers. In fact, New Balance sneakers, Timberland |
| 5. Finally, the hide may be oiled, waxed, dyed, rolled | | | | shoes, Simple Shoes and Keen shoes all plan to |
| or shaved depending on the desired outcome. | | | | purchase leather from the new eco-friendly tannery |
| The problems with this process are many. Not only | | | | in Vietnam opening next year. Support companies |
| are many chemicals used in the standard process - | | | | that support sustainable leather manufacturing and |
| because obviously modern tanneries are more | | | | understand the impact of you fashionable style! |