Life Cycle Assessment of a Plant-Based, Regionally Marketed Shampoo and Analysis of Refill Options

The environmental impact of a plant-based shampoo produced and marketed in Zurich, Switzerland, was analyzed using the life cycle assessment method. Beside the identification of environmental hotspots and mitigation possibilities, the focus of the study was on the analysis and comparison of different refill offers. The results of the study show that one hair wash using the investigated shampoo is related to greenhouse gas emissions of 161 gCO2eq. For all investigated impact categories, the use phase represents the dominant life stage, except for land use, which is dominated by the production of the purely plant-based shampoo ingredients. The environmental impact related to the use phase is highly sensitive on the consumers’ showering habits, such as water consumption and water temperature, due to predominantly fossil-based heating in Zurich. On the producer’s side, a switch to renewable energy sources both for heating and electricity is identified as most effective measure to reduce the environmental impact of the manufacturing phase. As to the product end-of-life, the results suggest that emissions of the shampoo ingredients after wastewater treatment have a negligible impact on freshwater ecotoxicity. In this context, a need for further research is identified with respect to characterization factors and specific removal rates in wastewater treatment plants. From a life cycle perspective, packaging production and disposal have rather low contributions. Offering refill possibilities can reduce the packaging related contributions by several percentage points, however, higher mitigation potentials are found for use phase and manufacturing.