Open Access

Natalie Fuss, Sabine Bornkessel, Thomas Mattern, Rainer Stamminger

• In the past few years, studies have been carried out to record and analyse the consumer behaviour of manual dishwashing. Manual dishwashing in households is performed in many ways that influence the use of resources. Furthermore, knowledge has been gained on the basis of experiments on how to optimize the use of resources in manual dishwashing. Optimization here means achieving the best possible cleaning performance with a minimum input of resources. This experimental knowledge, combined with the experience of everyday life, was transferred into Best Practice Tips. The aim of this study is to verify whether it is possible to save resources while applying these Best Practice Tips in comparison with the consumers' previous behaviour. In a laboratory study, 53 consumers from Europe (23 Germans, 30 other Europeans) were asked to apply the Best Practice Tips while washing up 12 place settings of dishes. The data gained were compared with that of previous studies recording consumers' everyday behaviour while washing up the same amount of dishes. The sample consisted of 113 European consumers and the sample of the second study consisted of 60 Europeans. On average, the 53 test participants applying the Best Practice Tips used around 60% less water, 70% less energy and 30% less detergent compared with the average everyday behaviour the other subjects used. Additionally, they achieved a slightly better cleaning result. An evaluation questionnaire showed that the Best Practice Tips were, in general, highly accepted; however, some concerns were given about their exact application in everyday life. Because of the wide variation of washing-up habits and resource consumption among individuals, the confidence intervals of the studies are rather large. The results should therefore be seen as tendencies on how resource savings are possible when people are trained how to optimize resources in manual dishwashing. Nevertheless, this study should be the basis for further ones in which the learning is verified in everyday life and over a longer period of time.