Residue from commercial rinse agents used in professional-grade dishwashers can damage the natural protective layer in the gut and contribute to the onset of chronic diseases, according to researchers at the Swiss Institute of Allergy and Asthma Research (SIAF), an associated institute of the University of Zurich (UZH). The study found that high doses of rinse agents killed intestinal epithelial cells and lower doses made it more permeable, potentially triggering inflammatory responses. The researchers identified alcohol ethoxylates, a common component of commercial rinse agents, as responsible for this reaction.

Commercial dishwashers typically involve circulating hot water and detergent for around 60 seconds at high pressure, followed by a 60-second washing and drying cycle in which water and a rinse agent are applied. However, in many appliances, there is no additional wash cycle to remove the remaining rinse aid, meaning potentially toxic substances remain on the dishes and can end up in the gastrointestinal tract.

The study used newly developed technology – human intestinal organoids and intestinal cells on microchips – to investigate what effect the components of commercial-grade detergents and rinse agents have on the epithelial barrier in the gut, the layer of cells that lines the intestinal tract and controls what enters the body. A defect in this barrier is associated with conditions such as food allergies, gastritis, diabetes, obesity, cirrhosis of the liver, rheumatoid arthritis, multiple sclerosis, autism spectrum disorders, chronic depression, and Alzheimer’s disease.

The researchers warn that the effect they found could mark the beginning of the destruction of the gut’s epithelial layer and trigger the onset of many chronic diseases. They call for immediate action to inform the public about this risk, since alcohol ethoxylates seem to be commonly used in commercial dishwashers. This study highlights the potential risks associated with commonly used household appliances and the importance of further research in this area to protect public health.