Since ancient times, leather has been used to create a wide variety of things, from shoes and bags to furniture and car interiors. It is a flexible, long-lasting, and highly sought-after material. But first, leather must be tanned, which turns raw hides into a durable, useable material that can withstand wear and tear and resist deterioration.
The benefits of tanning are numerous. First of all, it gets rid of the natural oils, proteins, and fats that are present in animal skins and can eventually cause the material to rot and deteriorate. By substituting tannins, which are water-soluble chemicals present in some plant species, for these components, tanning produces a material that is more resistant to deterioration and has a long lifespan.
Second, tanning can also alter the appearance and feel of leather, making it softer, smoother, and more consistent in tone. The hides are soaked in a tanning solution—which can be prepared from a number of materials, such as fruit, tree bark, and leaves—to achieve this. To create a stable, homogenous material that can be further treated and finished to produce various types of leather, the tannins penetrate the hides and interact with the proteins.
Finally, tanning can provide leather additional qualities like flexibility, resilience to heat and chemicals, and water resistance. This makes it perfect for a range of uses, including outdoor gear, footwear, upholstery, and clothes.
Although tanning is a necessary step in the production of leather, it may also result in a potent odor that is frequently connected to tanneries. The chemicals and organic material used in the tanning process, which can release volatile organic compounds (VOCs) into the air, are to blame for this odor.
Depending on the type of leather being produced and the tanning technique employed, several chemicals may be used throughout the tanning process. For instance, chrome tanning, a common technique for creating soft, supple leather, requires chemicals like chromium salts that can emit fumes and aromas.
The organic material included in animal hides, in addition to the chemicals employed in tanning, can also add to the scent of tanneries. Before tanning, the hides must be cleansed and soaked, which can release germs and other microbes into the air and produce an offensive stench.
Numerous tanneries have implemented a variety of strategies to reduce the smell of their facilities, including the use of closed systems to control odors, the installation of air filtration systems to remove volatile organic compounds from the air, and the use of more ecologically friendly tanning techniques that produce less scents. To lessen the impact on local populations, some tanneries have also placed their operations far from habitations.