What Is Chrome Tanned Leather?
Chrome tanned leather is made using a mixture of chemicals, salts, acids and dyes they are in baths containing acidic salts, soaking up the solution, once that step is carried out, they are ready for the chrome tanning process, the bath includes chromium tanning agents, the baths acidity is reduced as the tanning process goes through its cycle and the hides begin to soak the chromium agents.
There are many methods of tanning skins, but chrome tanning is by far the most common and the fastest way to tan a hide. Vegetable tanning is one of the safest as it uses natural tanning materials like bark extract and items from sumac bushes to naturally tan the hides with natural chemicals that are not harmful.
Chrome Tanned leather causes a multitude of hazards for workers and the environment, therefore FOC leather is becoming more widely used and preferred by some manufacturers today, FOC is free of chrome.
Depending on the type of chromium used, this will determine the issues this can have on your skin, as chromium in high amounts with skin contact can cause dermatitis, brief and occasional contact will not pose an issue. But this depends on the tannery the leather has been made in and the processes they use for tanning leather skins.
Leathers that have been produced in countries that are not that developed which can leave in excess amount of chromium causing skin rashes and in severe cases dermatitis.
A lot of tanneries today use what is called a wet blue to colour and finish off the tanning process, this is what’s made after the skins have been through the chrome tanning process. From here the skins can be finished off and coloured then sealed ready for sale to a leather merchants.
Around 75% of leather today is made using chromium iii tanning process, this process compared to older chrome tanning methods is much safer, in fact chromium is used in daily life like in vitamin pills etc.
Due to strict industry guidelines set by leather councils chromium iii chemicals are used predominately today in the tanning process, hexavalent chrome of chrome vi is not used in tanning leather as some report this causes miss information about the leather trade and causes global issues for companies working to strict guidelines and process within the law set down.
Some automotive manufacturers are opting for FOC leather today, which can be known as aldehyde tanning, this is the most common type of chrome free tanning. This uses glutaraldehyde, this process will require the use of more chemicals after tanning to help improve the leather properties.
FOM is a term given to leathers that are tanned without using metal during the tanning process, like iron, aluminium etc.
Then there are even newer types of FOC tanning called zeolite tanning, this process is even safer than chromium iii which is ultra-safe to begin with, zeology leather is chrome free, heavy metal free and aldehyde free. Making it extremely safe for users while leathers are being tanned and when used on leather goods.
Leathers tanned using the zeolite chemicals are given a different appearance to the traditional wet blues, they are now known as wet whites as they have this very white natural look to them, due to its bright white finish this enables leathers to be finished using even brighter colours than ever before, allowing for an even whiter white finished leather.
Zeology leather where it’s been tanned with zeolite produces leathers that are far superior in light fastness, grain tightness and heat resistance making it a far more stable leather skin.
Leather skins or as they are known prior to tanning as pelts are tanned to preserve the skins making them usable and this process changes molecule structures to protect and enhance the collagen fibre network.
Skins go through a strict process in the beamhouse operation, they are cleaned, dirt is removed, blood removed, hairs removed, salt removed, the collagen fibres are opened up and they are fleshed, once these chemical processes are completed they are then split into grain, splits for furniture or automotive uses.
Once the beamhouse operations are completed the next stages of tanning is protecting the collagen fibres form microorganisms, it’s during this stage that the collagen fibres are changed to leather.
Using chromium iii tanning chemicals is actually very safe, but people do sell this as chromium free, free of pollutants making out the tanning of hides are dangerous, when in fact they are far from dangerous.
The family of chromium is rather large, chromates are used in chrome plating to reserve metals from corrosion, also used in pigments for paints.