Integrated low-temperature washing and drying for sustainable hygiene of domestic laundry

Low-temperature laundering is promoted to reduce the environmental impact of domestic textile care; however, washing at ≤ 40 °C is insufficient for hygienic decontamination, rendering the drying stage critical, as microbial survival strongly depends on moisture availability and drying conditions. This study systematically investigates the antimicrobial efficacy of low-temperature washing combined with different drying methods under controlled, household-relevant conditions, and directly links hygiene performance to environmental impact using life cycle assessment (LCA). Cotton carriers inoculated with representative bioindicators were washed at 30 °C using a commercial detergent and subsequently dried by high- and low-temperature tumble drying, controlled indoor air drying, and simulated outdoor solar exposure (Xenotest). Low-temperature washing alone resulted in limited microbial reduction, whereas drying led to substantial additional inactivation. Both high- and low-temperature tumble drying eliminated most microorganisms (>7 log CFU cm⁻²), while simulated indoor air drying achieved significant reductions (∼6 log CFU cm⁻²), indicating that moisture reduction is a dominant mechanism of microbial inactivation, even without elevated drying temperatures. In this respect Xenotest treatment was less effective. The LCA showed that drying accounts for more than 50 % of the total environmental impact of the laundering process, with low-temperature tumble drying reducing overall impacts by approximately 20 % compared to high-temperature drying due to lower electricity consumption. By quantitatively linking microbial hygiene outcomes with environmental impacts, this study provides decision-relevant evidence for optimising domestic laundry practices, demonstrating that energy-efficient drying strategies can compensate for the hygienic limitations of low-temperature washing while significantly reducing the environmental footprint of textile care. • Domestic low-temperature washing does not meet hygiene standards. • Drying is essential for achieving hygiene, as all methods significantly reduced microorganisms. • High-temperature drying completely eliminated E. coli and C. albicans . • Low-temperature drying is effective and reduces environmental impact. • Combining low-temperature washing and drying provides hygiene and sustainability.