Leather
Leather is a strong, flexible and durable material obtained from the tanning, or chemical treatment, of animal skins and hides to prevent decay.
[1][2] Leather can be used to make a variety of items, including clothing, footwear, handbags, furniture, tools and sports equipment, and lasts for decades.
[1][2][3] Critics of tanneries claim that they engage in unsustainable practices that pose health hazards to the people and the environment near them.
The typical process sees tanners load the hides into a drum and immerse them in a tank that contains the tanning "liquor".
This currying process after tanning supplements the natural oils remaining in the leather itself, which can be washed out through repeated exposure to water.
Reptilian skins, such as alligator, crocodile, and snake, are noted for their distinct patterns that reflect the scales of their species.
[23] Kangaroo leather is also used for falconry jesses, soccer footwear,[24] (e.g. Adidas Copa Mundial[25]) and boxing speed bags.
The leather is often dyed black and covered with tiny round bumps in the natural pattern of the back ridge of an animal.
[32] Tanning is especially polluting in countries where environmental regulations are lax, such as in India, the world's third-largest producer and exporter of leather.
A review of the total pollution load decrease achievable according to the United Nations Industrial Development Organization[33] posts precise data on the abatement achievable through industrially proven low-waste advanced methods, while noting, "even though the chrome pollution load can be decreased by 94% on introducing advanced technologies, the minimum residual load 0.15 kg/t raw hide can still cause difficulties when using landfills and composting sludge from wastewater treatment on account of the regulations currently in force in some countries."
[34] In 2003 for instance, the main tanneries' effluent disposal unit was dumping 22 tonnes of chromium-laden solid waste per day in the open.
[36] After approximately 15 years of ignoring high court rulings, the government shut down more than 100 tanneries the weekend of 8 April 2017 in the neighborhood.
For instance, in Croatia in 2001, proper pollution abatement cost US$70–100 per ton of raw hides processed against $43/t for irresponsible behavior.
[38] In November 2009, one of Uganda's main leather making companies was caught directly dumping waste water into a wetland adjacent to Lake Victoria.
[39] Enzymes like proteases, lipases, and amylases have an important role in the soaking, dehairing, degreasing, and bating operations of leather manufacturing.
Although it is chemically irreversible, treatments can add handling strength and prevent disintegration of red rotted leather.
Subsequently, many sports use equipment made with leather, such as baseball gloves and the ball used in cricket and gridiron football.
In countries with significant populations of individuals observing religions which place restrictions on material choices, vendors typically clarify the source of leather in their products.
Such labeling helps facilitate religious observance, so, for example, a Muslim will not accidentally purchase pigskin or a Hindu can avoid cattleskin.
Judaism forbids the comfort of wearing leather shoes on Yom Kippur, Tisha B'Av, and during mourning.
Many forms of artificial leather have been developed, usually involving polyurethane or vinyl coatings applied to a cloth backing.
[45] Another alternative is cultured leather which is lab-grown using cell-culture methods,[46][47][48] mushroom-based materials and gelatin-based textile made by upcycling meat industry waste.
