The leather industry is one of the most resource-intensive and environmentally impactful sectors in global manufacturing, generating significant volumes of liquid effluents, solid waste, and chemical pollutants. Adopting Best Available Techniques (BAT) is essential not only for regulatory compliance but also for reducing operational costs and improving environmental performance.
The authoritative reference document for the leather sector is the EU Best Available Techniques Reference Document (BREF) for the Tanning of Hides and Skins, published by the European IPPC Bureau. Additionally, the UNIDO Leather Panel provides guidance for developing countries on cleaner leather production.
Water Management BAT
- Install water flow meters at all supply points and maintain monthly water consumption records
- Switch from continuous “running water washes” to batch washes to dramatically reduce consumption
- Reuse water from hide washing (before main soaking) in the Pre-Soaking process
- Collect and reuse liming process water in the next liming batch after filtration — reducing sulfide [S2⁻] loads by up to 70% and lime [Ca(OH)2] by up to 93%, cutting overall BOD by 7% and COD by 26%
- Reuse deliming wash water in Post Liming; Post Deliming & Bating wash water in Pre-Soaking
- Collect and reuse Wetback water and wash water in successive lots
- Reuse pickling and tanning floats in successive cycles
- Collect Rechroming water for reuse or redirect to in-house chrome recovery plant
- Reuse Post Neutralisation Washing Water as Neutralisation Water for the next lot
- Recycle cooling water from vacuum presses, sammying machines, pumps, and compressors
Raw Material & Chemical Management BAT
- Recover and reuse curing salt from raw hides — approximately 50 kg of salt can be recovered per 1,000 kg of raw stock
- Reduce salt use in hide preservation by adding environmentally acceptable antiseptics (boric acid, acetic acid, sodium sulphide) or commercial bactericides; reduces soaking wastewater pollution by up to 50%
- Process green (unsalted fresh) hides where chilling and cooling facilities are available
- Avoid dyes containing hazardous heavy metals such as lead, cadmium, and chromium VI
- Avoid fat liquoring agents based on chlorinated paraffins; use eco-friendly synthetic fat liquors instead
- Avoid benzidine-based and other azo-dyes that may reduce to carcinogenic amines (restricted under ECHA REACH Regulation)
- Avoid finishing pigments containing environmentally hazardous heavy metals
- Use water-based finishes and solvents wherever possible
Energy Efficiency BAT
- Insulate all surfaces above 50°C with optimum insulation thickness
- Remove redundant utility lines and optimise routing
- Periodically evaluate efficiencies of utilities — boilers, generators, compressors — across generation, distribution, and utilisation
- Inspect steam, hot water, freshwater, and compressed air lines for leakages regularly
- Use solar water heating for process water
- Use solar air drying for hides and skins wherever feasible
- Integrate photovoltaic systems into existing power supply infrastructure
- Use desalting drums to improve process efficiency
- Switch to newer drum tanning technology
Workforce & Management BAT
- Build training routines for staff at all hierarchical levels on environmental and safety procedures
For organisations implementing an environmental management system alongside these techniques, alignment with ISO 14001 Environmental Management is strongly recommended. The Leather Working Group (LWG) also provides an internationally recognised environmental audit protocol for leather manufacturers.
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