Tanning is one of the oldest human technologies. There are many different tanning processes. Some have been perfected over the centuries and are still being used today, others are no longer considered to be state of the art. The most widely used methods of tanning around the world are chrome tanning, the so-called Wet White tanning using synthetic tanning agents and vegetable tanning using vegetable tanning agents (e.g. leaves, bark, wood or fruit). More than 80 percent of the tanning done worldwide uses the chrome tanning process – and so do we at the Heinen leather factory.

No tanning process has (yet) been developed that is 100 per cent ecological and which can be used on an industrial scale. Every tanning process has certain advantages and disadvantages. Of all the tanning processes, various studies have shown that the chrome tanning process is the most ecological. The wastewater produced by chrome tanning is the least environmentally harmful as is shown in a study don by LGR and FILK (Research Institute of Leather and Plastic Sheeting).

Comparison of standard tanning processes

Comments:

The COD value (COD: chemical oxygen demand) of wastewater indicates how much oxygen and thereby how much energy is needed to purify the wastewater.

The AOX value (AOX: adsorbable organohalogen compounds) is a summation parameter in wastewater analysis that measures the amount of non-biodegradable or very poorly biodegradable, poisonous substances in the wastewater.

The G L20 value is a measure of how poisonous the wastewater is for fish.