Lifecycle Assessment Of Leather (LCA)
The question, ‘what is the cleanest, greenest or environmentally sustainable tannage type?’ is one that is often asked. Without enough understanding, it is repeatedly assumed that leather tanned with vegetable extracts must always be better, but the reality can be quite different.
“Tanning is just one of around twenty major processes that a hide goes through to be converted from raw pelt, to a tanned and finished piece of leather”
Tanning is just one of around twenty major processes that a hide goes through to be converted from raw pelt, to a tanned and finished piece of leather. All the other elements are largely the same whether it be chrome, vegetable or aldehyde (chrome free) leather. The residual hair, fats, proteins, pigments and interfibrillary matter still have to be removed using sulphides, limes, acids, alkalis, emulsifiers, enzymes etc. are all part of the tanning process, regardless of what the tannage type is. Then the leather is generally dyed, fatliquored, re-tanned, dried and finished.
To focus on just the “tanning” aspect of the leather making is over simplistic. To better understand the impacts of the different tannage types, a detailed life cycle analysis of three tanning systems; vegetable, chrome and aldehyde (wet white) using the ISO14040 standard as a basis has been done.