Sustainability is a guiding principle for a responsible, future‐oriented 21st century lifestyle and this already begins in private households with the daily household tasks. Approximately 25% of an average household's electricity consumption is required to do the laundry and dishwashing – 5% alone is for washing clothes with a corresponding energy consumption of 6 billion kilowatt hours. In addition, 600 000 tonnes of detergent and 330 million cubic metres of water are used for textile care in Germany. These figures provide the rationale for the scientific study of current practices of using washing machines and for a resulting estimate of the latent energy‐saving potential in German households. In the context of the in‐home study presented here, 236 private households throughout Germany were studied with respect to their washing practices and existing knowledge about topics on the sustainable, energy‐saving use of their washing machines. Overall, across all households 2867 wash cycles were individually recorded and subsequently analysed over a 4‐week period. The results of this study show that washing machines tend to be underloaded, and therefore maximum loading of the machines could lead to a reduction of wash cycles per household. With respect to detergent dosage, it was determined that the consumer does not adjust the dosage to the textile type, load size, soil level and/or water hardness, and this can lead to under‐ or overdosing depending on prevailing conditions. Finally, the selection of the wash temperature showed a 90°C/95°C programme was only chosen in 2.3% of all recorded wash cycles, however, every fourth cycle was completed at 60°C. Therefore, adjusting the load size and detergent dosage as well as selecting the right wash temperature are key themes to be taken into account in future consumer communication about energy‐saving households.

Laundry washing consumes resources. It is therefore a clear task for everyone, especially the industry and the consumer, to try to reduce the amount of resources needed as much as possible. Many possibilities and alternatives to the classical cleaning process using a washing machine and a readily formulated detergent are in discussion and are offered to the consumer. Task of this study is to investigate the effectiveness of some of these alternative methods to see whether the task to save resources can be accomplished by them. This is done by carrying out washing performance tests in a common household washing machine using stain monitors and stain strips as indicators for the washing effect in a 30°C and 60°C cotton program and comparing those alternatives (soap nuts, soapwort, two kind of wash-balls) with the use of regular detergent and washing with pure water. As result it is shown, that none of the investigated alternative cleaning methods does deliver any washing effect better than the result achieved with pure water, besides for soapwort that also included other surfactants. Interesting to note that on most stains the use of just 50% of the detergent delivers already a cleaning performance not much lower as 100% of detergent does provide.

No abstract