Are your shoes, handbags, watch straps and possibly your coat or jacket made from leather? If so has the tanning process used to treat the leather been done safely? What tanning process was used? Are your leather handbags toxic?
Before being made into fashion products, animal skins are processed in factories called tanneries. Tanning is the process of treating animal skins or hides, and turning them into leather. Tanning makes animal skins workable, more durable and makes them less likely to breakdown. The customary procedures of tanning use an acidic chemical known as tannin, from which the tanning process acquired its name. Tannin is actually the German word for oak or fir trees from where tannin was first isolated. Tanning includes a process which permanently changes the protein structure of animal skin, converting hide into leather.
Tanning techniques have developed considerably since the ancient times and today tanning can be performed using either vegetable or mineral methods such as the use of chrome, alum, zirconium, titanium, iron salts and other minerals.
The word rawhide relates to a worked hide which is untanned. Rawhide is treated by first getting rid of the flesh, fat and hair, and then by cleaning and treating it with chemicals:
- Either a solution of lime, a process known as liming, or
- Wood ash (lye), a process known as bucking.
After the chemical treatment the hide is scraped over a beam with a fairly blunt knife, then the treated hide is dried.
Sometimes this same process is used as a preparation step prior to the tanning process. It cleans the fiber network of the animal skin allowing the tanning agent to penetrate easily. An alternative method to de-hair, de-grease and de-salt the animal skins prior to tanning, is to soak them in water over a period of 6 hours to 2 days. To stop damage to the skin by bacterial contamination during the soaking period, bio-cides and fungicides are added.
Dyes are added during the tanning process. Leathers can be dyed to achieve a range of beautiful colors. During a recent trip to Morocco I visited the Moroccan Leather Tanning Vats located on the outskirts of the old city of Fez. The multitudes of colored vats and the smell were most notable. These vats have been there for centuries. In ancient times, tanning was considered to be a highly noxious and really smelly trade. Because of this the tanning vats were usually found on the outskirts of a town. This bad smells were due to a combination of urine, animal feces and decaying flesh. In fact, tanning by these old traditional techniques produces such rotten odors, that even today, tanneries using old methods are still located in out-of-the-way places. The ancient craft of leather tanning and coloring is passed down from father to son and the craft is kept within the family.
In order to enhance tanning techniques, some tanneries have implemented the use of some toxic chemicals. These include
- Mercury based biocides (Banned since 1980)
- Pentachlorophenol (PCP’S) (Banned since 1980)
- Chromium Salts
Chrome tanning is a nineteenth-century invention, developed as an efficient, quick and inexpensive way of treating animal skins. The ease and cheapness of this process has made it very attractive to the mega-brands. A large percentage of luxury goods companies, high street as well as contemporary brands have opted to use this method in the production of the leather for their leather goods.
So why is chrome-tanning an issue? The fact is, chrome tanning is a terribly high price to pay when you take into account environmental impact.
Chromium III sulfate is used in the chrome tanning procedure. Chromium III is recognized to be the most efficient and effective tanning agent. Chrome tanning is significantly quicker than vegetable tanning and it produces a really stretchable leather which is great for producing handbags and other leather goods.
Chromium III compounds used in tanning are significantly less toxic than Chromium VI. However chromium III easily changes to chromium VI by boiling and sun-drying. Chromium VI is a heavy metal and is very toxic, carcinogenic and environmentally harmful. Regrettably chromium VI is a common carcinogenic waste product from leather manufacturing. It has been detected in the food chains and water supplies of both developing and developed countries. If chromium VI runoff leaches into the soil it may be taken up by vegetation and/or ingested by animals. Approximately 25% of chickens in Bangladesh were contaminated by risky levels of chromium VI which causes a significant national health issue. If you or your baby suck on a chrome-tanned leather purse the mouth may go numb. Toxic chromium salts in this bags may be toxic to your health.
Luxury brands and others still use chrome-tanned leather to produce their leather goods without understanding or caring about the environmental impact of the method, nor the well-being of its customers. But as long as the consumer continues to purchase chrome-tanned leather goods, there is little motivation for luxury brands to shift to vegetable tanning, a process which takes longer, is more costly, and does not as effectively cover up low quality skins.
Vegetable tanning is a slower and more costly procedure, but it is considerably safer. Safer for the environment and safer for you! This is the tanning method you must expect and demand from the manufacturers of leather goods. Vegetable tanning is the process used by COT one of my suppliers. They manufacture exquisite Italian leather handbags which are really great.
Vegetable tanning uses the traditional tannin technique. Tannin is isolated naturally from the bark and leaves of many plants such as chestnut, oak and other trees. Tannins bind to the collagen proteins in the skin and coats them. This results in the hides becoming less water soluble, and more resistant to bacterial overgrowth. The vegetable tanning process also causes the hide to become more flexible. Hides are stretched on frames and immersed for several weeks in vats of increasing concentrations of tannin. Vegetable tanned hides are flexible and is used for the manufacture of handbags, luggage as well as furniture
Vegetable Tannning in Fez, Morocco
Tanning Using Other Minerals
Other forms of mineral tanning utilize chemicals such as alum, zirconium, titanium, iron salts lead to skins known as wet white and is much more eco-friendly. Chrome tanning produces a “wet blue”.
Tanned Leather Goods Last a Lifetime
Leather goods, even if constantly used, can last for a lifetime. If a leather bag is properly tanned and finished correctly, it will be decades before it needs repair. However, many luxury brands now manufacture leather goods to a much lower standard. All in the name of profit.
Some luxury handbags which cost over a $1500, will last only last for a few years before they need to be repaired. Others will simply fall apart. Cost-cutting tricks in the manufacturing process include:
- Makers compromise on the quality of leather and the tanning process
- Mega-brands use chrome-tanning rather than more eco-friendly approaches
- The edges of handbags are finished with acrylic varnish which cause the material to crack within a couple of years. Techniques such as turned edges or burnishing which are more time-consuming should be employed because they result in a product that last for decades
- Manufacturers use poor quality hardware on their products, such as white metal rather than solid brass or plated steel
- Modern stitching techniques are poor quality. They no longer tend to use traditional saddle making techniques which are stronger and more robust
These cost cutting measures have undermined the quality of the expensive brands. A leather good such as a handbag cannot be called a luxury article if the brand has compromised on materials and manufacturing processes to such an extent that the product will last only a few years, rather than decades. Price on its own does not determine if a product is luxury or not. Several brands, including some of the most celebrated names in the luxury industry, have damaged their good name by putting volume production and overall profits before quality. And they don’t only damage their name, they damage the environment and endanger public health as well.
It is far better practice for the mega-brands, at least, to produce leather goods utilising techniques and procedures that mean the goods will stand the test of time. It is also better for the environment and boosts the brand’s status and popularity. The accountability of changing to better processes lies in the hands of the fashion houses and luxury brands who need to be driven by a concern for the environment rather than financial outcomes.
It would be a smart move to record the leather tanning method on the label so that the consumer can vote with their feet, or their pockets as it would turn out. Consumers could chose eco-friendly brands. Don’t let your leather goods affect your health.