Measuring the Environmental Footprint of Leather Processing Technologies

The selection of materials and manufacturing processes often determines most of the environmental impact that a product will have during its life cycle. In directing consumption toward products with the least impact on the environment, measuring and comparing material alternatives with site-specific data is a fundamental prerequisite. Within the apparel and footwear industry, some famous brands have recently been basing their advertising on the claim that vegetable-tanned leather is more environmentally friendly than chromium-tanned leather. However, there is a lack of scientific research assessing and comparing vegetable- and chromium-tanned leather in a wider context than the toxicity of chromium. To fill this gap, this study measured and compared the carbon, water, and energy footprint of vegetable and chromium leather processing technology and intermediate processing stages in 12 selected tanneries in seven different countries worldwide. Each tannery proved to be very individual, and therefore attempting to perform this type of analysis without simply producing meaningless generalities is a challenge for companies, researchers, and regulators. The variability in results demonstrates that secondary data for the tanning phase should be utilized with caution in a decision-making context. The use of primary data would be advisable for life cycle assessment studies of leather goods. No significant differences were found in the footprint of vegetable and chromium leather processes, but these are only indicative findings and need confirmation in further studies. An important area needing investigation is then how a fair comparison can be made between renewable natural materials and nonrenewable materials used in both leather-processing technologies.