The European Union leather industry, 70% of which is located in Italy and Spain, represents a significant share of global production and is an important economic sector for the whole EU. However, leather production is traditionally responsible for heavy environmental impacts. In particular, industrial leather tanning entails significant use of:
In addition, there are difficulties in recycling and disposal of semi-finished or finished products containing toxic metals. The whole sector needs to significantly improve the environmental sustainability of its processes.
The LIFETAN project would demonstrate innovative natural products and technologies for the degreasing, fatliquoring, bating (softening), dyeing and tanning phases of leather production. It would build on the results of previous LIFE projects that substituted toxic chemicals used during the leather tanning cycle to produce significantly more sustainable products. In particular, the project would:
- Use natural fatliquoring and degreasing products that do not exceed the legal limits for hazardous substances in leather goods;
- Obtain the European Ecolabel for the fatliquoring and degreasing products;
- Reduce contamination of waste water by enhancing the biodegradability of fatliquoring and degreasing products;
- Recycle and use poultry waste in the bating phase of the tanning cycle;
- Design natural dyes based on lactose from waste milk serum that comply with EU's REACH chemicals regulation; and
- Apply an innovative chrome-free tanning technology.
The LIFETAN project demonstrated that natural agents could be used as substitutes of conventional toxic products in the whole leather tanning processes to produce goods with a higher eco-sustainability profile. The project identified five tanning cycles, which use natural/naturalised agents and combinations of them, and demonstrated that the processes are technically feasible on a pre-industrial scale. Chemical and physical analysis of the leathers samples showed that they have the same commercial qualities as those treated with conventional agents. Compliance with the criteria of the European Eco-label for footwear (Decision 2002/231/EC) was also verified; the results confirmed that all leather types comply with the recommended values and are suitable for footwear manufacturing.
The project thus showed that tanneries can significantly reduce the environmental impact of their wastewater by adopting the LIFETAN tanning cycles. Environmental benefits include:
- Avoidance of heavy metals such as chromium in the wastewater of the tanning process, since the process is 100% chromium-free;
- Avoidance of heavy metals in wastewater treatment sludge with a subsequent reduction in the sludge management of 20-30%;
- Substitution of traditional formulations based on raw materials of petrochemical origin or toxic (i.e. Chloroparaffins, sulphochloroparaffins, synthetic chemical dyes, alkyl phenyl ethoxylates);
- Reduction of the COD of the global tanning process of 11-19% (up to 22.4 % in 1000 kg test but lower than the expected 30%;
- Reduction of the BOD5 of the global tanning process of 2-20%;
- Reduction of the NTK of the global tanning process of 52-67% (higher than the expected 30%)
- Increase in the biodegradability of wastewater of 8-21%.
The project team also evaluated the economic viability by carrying out two case studies in Italy and Spain. The natural products entail higher costs than products conventionally used in the tanning process, but the high-quality market for the goods could accept slightly higher prices. Moreover, the economic assessment showed that the production scale influences the costs of natural agents: the bigger the scale the lower is the cost. The future new tanning agents and their application in the tanning industry is therefore dependent on the will of chemical manufacturers to get involved and invest in these new formulations. The introduction of the natural products would help improve environmental status of a geographic area.
Further information on the project can be found in the project's layman report (see "Read more" section).