Conventionally skins/hides are tanned with metal-ions and vegetable tannins. Environmental constraints on the discharge of toxic metal-ions and poor biodegradable vegetable tannins in the wastewater have become a serious issue. In this invention, the pelts are tanned using eco-benign bio-molecules other than vegetable tannins to reduce the pollution loads. Performance of the leathers is on par with conventionally processed leathers.