The use of oxidative chemicals for the removal of hair from cattle hides in the beamhouse

Conventional dehairing employs salts of sulfide for the reductive degradation and removal of hair from hides. Although sulfide salts are very efficient and effective in the removal of hair; their use is environmentally costly because they contribute to biological and chemical oxygen demand. In addition, the salts could react with acid to produce toxic hydrogen sulfide gas. In our ongoing study of the use of alkaline oxidative chemicals as replacements for sulfides in the beamhouse, we have developed three different dehairing protocols -- alkaline sodium perborate and alkaline hydrogen peroxide amended with either potassium cyanate or urea. Alkaline hydrogen peroxide/urea was very effective in removing hair, but it also led to extensive damage to the hide. Alkaline sodium perborate effectively removed the hair from cattle hides without any sign of grain damage. Leather produced from hides that had been dehaired using the sulfide-free dehairing had at least as good physical properties as leather produced from hides dehaired using sulfide. In addition, the uptake of the dyes used to make crust leather was better for the hides that had been oxidatively dehaired relative to those that had been sulfide-dehaired.