With Cleantan®, all the chrome used in the tanning process ends up in the leather and not in wastewater. Therefore this revolutionary tanning technique requires far less chrome.
There are various methods of calculating chrome use in conventional tanning, leading to different amounts of potential chrome saving with Cleantan®. These discrepancies are illustrated in the table showing some numbers from different sources: a chemical supplier’s brochure, a professional tanner’s recipe and a report by unido (United Nations Industrial Development Organization).
While the differences in dry weight, chrome content and chrome-III-salt availability are relatively small, the differences in chrome content of the wastewater are enormous: per ton of skin, a professional tanner claims 16 to 25 kg of waste chrome, while unido reports an amount of 32 to 44 kg.