’Reverse’ tanning process could revolutionize leather industry

A new ’greener’ and cleaner chemical process* could revolutionize the leather-tanning industry, according to a report in the Feb. 15 issue of the American Chemical Society’s journal Environmental Science & Technology. ‘Reverse’ leather tanning, which essentially works backward from the point where conventional tanning ends, saves time, money and energy while drastically slashing water use and pollution, say researchers at the Central Leather Research Institute in Adyar, India.

From pre-tanning to finishing, conventional leather tanning requires about 15 steps, which produce enormous amounts of wastewater and pollutants, including sulfides, chlorides, sulfates and other compounds. The new approach flips the process around and eliminates some of the steps, which results in multiple and substantial production efficiencies, the researchers say.

In the new process, for instance, prior to tanning, the skins are treated with chemicals normally used after tanning is completed. According to the researchers, the reverse process produces leather that is comparable to conventional tanning, but requires 42 percent less time, 54 percent fewer chemicals, 42 percent less energy, 65 percent less water and cuts emissions of key pollutants by up to 79 percent. The results were achieved without changing chemicals or using new ones, the researchers note.

In addition to costing less and being “greener” than conventional tanning, the reverse process is “easy-to-adopt” and could help the global industry overcome emerging environmental and economic concerns, the researchers conclude.

*Green chemistry is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances.