TANNERIES AND LEATHER SECTOR
The origins of leather production date back over 7,000 years and, today, leather remains a strong and durable natural product used in various applications. It is considered circular in nature since it is a by-product of the meat industry. The global leather market is valued at over USD 270 billion annually (in 2022) and serves as a vital and accessible manufacturing export source for countries in the Global South1.
Being made from natural and renewable resources, leather has the potential to have a lower environmental impact compared to most synthetic fibres, which are plastic-based and linked to the petrochemical industry and fossil fuel emissions2.
The traditional techniques of drying the hides and skins in the sun, preserving it with salt or through smoking, and tanning the leather with plant-derived tannins, laid the foundation for the production methods still used today. The modern leather-making process involves three main stages: preparation to tanning, tanning, and processing the tanned leather. As a crucial first step, hides are preserved to prevent decomposition through methods such as air-drying, salting, or pickling before reaching the tannery. At the tannery, the hides undergo soaking (to remove the salt), liming (to loosen hair), and cleaning processes, including deliming, bating, and pickling, to prepare them for tanning. Tanning stabilises the hide by displacing water in the protein fibres, thereby binding these fibres together. Tanning can be done by using plant-derived tannins (vegetable tanning) and can take weeks to months, resulting in firm, water-resistant leather. Approximately 10% of all leather is vegetable tanned. In contrast, mineral tanning, often using chromium salts, is faster (taking hours or days) and produces softer, more pliable leather.
Beneath the allure of this treasured craft lies a more complex story. All these production processes involve various chemicals and generate both effluent and solid waste (hair, grease, oils, fleshings and trimming waste)3. If not properly treated, these can have harmful environmental effects on air, water, and soil. It can also pose health risks to workers handling hazardous chemicals, especially trivalent chromium that becomes hexavalent chromium in the oxidation process (which is a carcinogen), as well as to communities downstream that depend on the surrounding environment. See the schematic below that shows pollution pathways that could potentially emanate from untreated tanneries waste and processes.

How is SMEP intervening to address these challenges?
Following an open and competitive procurement process, SMEP contracted a range of grantees that aim to address environmental pollution emanating from this sector through innovative solutions within the tanneries value chain. Key impact pathways for this procurement stream address pollution mitigation, chemical reduction and/or substitution (and the correlation with human health), innovations in technology and traceability, policy reform, and supporting suppliers to comply with changing standards and certifications.
It is anticipated that the SMEP pilots will contribute to strengthening an enabling environment in the implementation countries. Specifically, the grantees are focusing on the following areas:
- Traceability Systems: The University of Northampton is leading the development of a traceability system in Bangladesh, while WWF-Pakistan is piloting a similar system in Pakistan.
- Waste Valorisation: Various waste valorisation solutions (trimmings, fleshings, etc.) are being piloted or scaled as part of the SMEP projects. CSIR-CLRI India is leading a project to be implemented in Ethiopia, with additional efforts from WWF-Pakistan in Pakistan.
- Environmental Pollution Reduction: Several biotechnology solutions, such as enzymatic treatments, are being piloted to replace hazardous chemicals used in specific stages of the leather production process.
- Occupational Health and Safety Compliance: The Ethical Trading Initiative is supporting the capacity of several tanneries in Bangladesh to comply with environmental and occupational health and safety regulations as well as international standards to enable market access for medium sized operations in the Savar Tanneries Estate.
Pakistan Leather Sector: Traceability, Cleaner Production and Circularity
PAKISTAN
LeatherTrace Bangladesh
BANGLADESH
Improving the environmental and social conditions in the Tannery Industrial Estate in Savar, Bangladesh
BANGLADESH
The Green Tannery Initiative
Led by CSIR-CLRI India, this project aims to enhance the sustainability of Ethiopia’s leather sector by implementing eco-friendly practices. It seeks to replace harmful sodium sulphide with enzymes for unhairing and to develop advanced waste management technologies to convert tannery solid wastes, such as hair and fleshings, into value-added products, thereby reducing environmental and health risks.
ETHIOPIA
REFERENCES
1 & 3. Hira, A., Pacini, H., Attafuah-Wadee, K., Sikander, M., Oruko, R., & Dinan, A. (2022). Mitigating Tannery Pollution in Sub-Saharan Africa and South Asia. Journal of Developing Societies, 38(3), 360–383. https://doi.org/10.1177/0169796X221104856
2. Stockholm Environment Institute Report. Manufacturing Pollution in sub-Saharan Africa and South Asia: Implications for the environment, health, and future work, 2020. SMEP Programme