Doing the dishes spoils more than your hands

People who despise dishwashing chores and long for a dishwasher can take a guilt-free trip to their nearest electrical store. A new study shows that handwashing dishes wastes up to ten times more water and energy than an economy dishwasher.



Edie News Service reports that 75 volunteers from seven European countries were recruited by the German University of Bonn to wash up a typical family load of 140 pots and plates coated with hardened egg, spinach and margarine.



To the surprise of Professor Rainer Stamminger, author of the test study, handwashing was found to use between 20 and 345 litres of water, and 1 to 12 kWh. The average was 88 litres of water and 2.4kWh of energy, compared with a conventional European dishwasher that uses around 15 to 20 litres of water and 1kWh of electricity.



Professor Stamminger also observed a wide range of washing up methods. “Whether it be a housewife or a househusband, a German or a Pole, a Spaniard or a Turk, they all have different ways of doing the washing-up,” he said. German and British test handwashers were more economical than their Spanish and Turkish counterparts, though the Spaniards produced the cleanest dishes. The performance of the Germans, who are supposed to be particularly clean, was no more than mediocre, adds Stamminger.



“We were able to characterise three entirely different types of [human] dishwasher,” says Stamminger. The super-dishwasher attaches considerable importance to a good result, while the dishwashing economiser manages with as little water, energy and detergent as possible. The carefree dishwasher doesn’t worry about the amount of water or energy used or the result.



The Professor’s tips for environmentally friendly dishwashing by hand include preventing the food from hardening on the plates, soaking them prior to washing, and using a main hot water bath followed by a cold wash rinse.

Check Also

Waste management poses challenges, but could unlock major environmental and economic gains

Every day, the city of Rio de Janeiro, one of the largest metropolises in the Southern Hemisphere, generates 17,000 tonnes of waste, ranging from large industrial debris to candy wrappers bought innocently at newspaper stands. While this waste presents a serious and urgent environmental challenge, it also fuels an increasingly significant portion of the economy, with benefits extending beyond financial gains. - When we look at developed European countries, many are already recycling between 40% and 50%, with some reaching 60%. From an economic standpoint, both recyclable materials and organic waste hold tremendous value - stated Adalberto Maluf, National Secretary for Environment and Environmental Quality at the Ministry of the Environment (MMA), during the Methane Forum: Climate Emergency Brake, at the Rio Nature and Climate Week. Citing a 2025 report, Maluf mentioned that Brazil literally throws away R$27 billion annually, while municipalities spend significantly more - R$45 billion - managing all this waste, often overlooking the environmental impact or economic potential buried in landfills and dumps. - We spend R$45 billion to collect and dispose of waste in landfills, yet we manage to recycle less than a third of the potential. I believe it will be necessary to review contracts, create performance-based remuneration mechanisms, and pay for both effectively sorted materials and those diverted from landfills - he added. According to the IBGE, 60.5% of Brazilian municipalities adopt some form of selective waste collection, and several initiatives serve as examples of how to manage city waste. In his panel presentation, Bernardo Ornelas, Project Coordinator at the Rio de Janeiro Municipal Urban Cleaning Company (Comlurb), highlighted Ecoparque do Caju, a national benchmark in waste management and recycling. There, received materials are sorted and can be used for biogas production, organic compounds for urban gardens, or human consumption, in the case of still...