Introduction: Washing laundry is one of the basic tasks in every household. The EU Directive on Water, Energy and Waste regulates the use of laundry programs at lower washing temperatures (30-40 °C) and lower water consumption, mainly due to the large amount of consumed electricity and waste water disposal. Therefore we are balancing the efficacy of laundry washing and its impact on the environment. Purpose: This study aims to analyse the effectiveness of soil removal and bacteria reduction in different washing scenarios combining temperatures (40 °C and 60 °C) and reference detergent concentrations. In last step we analysed the environmental impact of different washing scenarios. Methods: We tested the efficacy of standard soil removal from cotton and the reduction of E. coli, S. aureus and P. aeruginosa on cotton carriers at temperature 40 °C and 60 °C with different concentrations of standard detergent (5 g/L, 10 g/L in 20 g/L). A life cycle analysis for different washing cycles was also performed. Results: The results show that washing at 40 °C and 10 g/L was the most effective and resulted in good removal of standard soiling. However, bacteria reduction was highest at 60 °C, 5 g/L and 40 °C, 20 g/L (> 5 log CFU/cm2). With the 40 °C, 10 g/L scenario, we approached the standard requirements for household laundry of ~ 4 log CFU/carrier reduction and good soil removal. Discussion and conclusion: We found that we have an increased positive effect of the detergent on the removal of standard bacteria and a partially positive effect on the removal of standard soil. With the help of the LCA analysis, we found that increasing detergent has a large impact on the environment. Manufacturers of detergents are thus faced with a new challenge, how to prepare formulations of detergents that will be effective in removing bacteria and standard soil and at the same time will have a positive impact on the environment.
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