Water consumption by rinse-off cosmetic products: The case of the shower

Abstract

Objective: This article measures and discusses the effects of different shower gels on the consumption of water used during a shower. Methods: A sensory panel was created for quantifying water consumption associated with the use of shower gels. Fifteen French panellists were recruited (age: 59 ± 7, height: 163 cm ± 9 and weight: 68 kg ± 20) and trained to assess rinsed skin in a standardized way. Effective panellists were then asked to assess 25 shower gels covering the variety of existing products on the market. Results: Results showed that the average volume was 4.77 L for heating the water and wetting the body and 4.15 L for rinsing the shower gel off the full body. We observed a significant shower gel effect (p < 0.0001) with the water volume needed to rinse the 25 shower gels ranging 3.21 L to 5.65 L. Conclusion: This paper demonstrates the impact of shower gel formulation on water consumption during a shower. It thus demonstrates the importance of formulating shower gels to reduce the total amount of water needed to shower. It also introduces the distinction between ‘useful water’ which refers strictly to the volume of water objectively needed to rinse off a product and the ‘used water’ which refers to the total shower volume of water. This distinction helps to better strategize actions in order to reduce water consumption from rinse-off cosmetic products used during showers.