A 2023 laboratory study from the Swiss Institute of Allergy and Asthma Research found that dishwasher rinse aid, not detergent, damaged human gut lining cells and loosened the barrier they form, and identified alcohol ethoxylates, a class of surfactant, as the component responsible. The cells were exposed at the concentrations used in professional dishwashers. The study was done on cells and tissue models, not in people, and it did not measure household dishwashers. Those two limits are the study’s own, and they are the difference between what it found and what a headline about it might suggest.
The study
Gut epithelial barrier damage caused by dishwasher detergents and rinse aids
What it does not show. The study was done on cells and tissue models, not in people, so it measured barrier damage in a dish rather than any health outcome in a person. The concentrations the authors tied their findings to are those used in professional dishwashers, and the residue they measured came from professional machines. The abstract reports no measurement of household dishwashers or of what reaches a person from them. The link to chronic inflammatory disease in the paper's background is the hypothesis that motivated the work, not a result of it. Our reading is of the PubMed abstract. The full text is not open access.
Abstract read Sep 30, 2026 on PubMedWhat was studied
The researchers grew human gut lining cells in three laboratory models. The first was a layer of cells on a permeable support, a standard setup for measuring how tight the seal between cells is. The second was organoids, small three-dimensional clusters of gut tissue. The third was a gut-on-a-chip, a device that runs fluid past the cells the way the gut does. They then exposed the cells to dishwasher detergent and to rinse aid, the product that lowers water’s surface tension in the final rinse so water sheets off dishes instead of beading, as our rinse aid explainer describes.
They measured four things. Whether the cells died. The electrical resistance across the cell layer, which falls when the seal between cells loosens. How much material leaked between the cells. And the appearance of the tight junctions, the protein structures that hold neighboring cells together. They also read the cells’ gene and protein activity to see which processes changed.
What it found
The damage the researchers measured came from the rinse aid rather than the detergent. It scaled with the dose, and it was still measurable at a dilution of one part rinse aid in 20,000 parts water. In all three models the rinse aid loosened the barrier. Resistance across the cell layer fell, leakage between cells rose, and the tight junctions stained irregularly under the microscope.
The researchers then tested the rinse aid’s ingredients one at a time. Alcohol ethoxylates, a class of surfactant used to make water spread and rinse cleanly, produced the strong toxic and barrier-damaging effect on their own. The gene and protein readouts showed changes in cell death, inflammation and immune signaling at the concentrations used in professional dishwashers.
One more finding sits apart from the cell work. The researchers collected the residue left on dishware that had been washed in professional dishwashers and found it still carried enough rinse aid to damage the cells.
What it does not show
The study was done on cells and tissue models. It did not study people, and it did not measure any health outcome in a person. A loosened barrier in a dish is a laboratory measurement, and the step from that measurement to a disease in a person is a hypothesis the paper states as its motivation, not a result it reports.
The concentrations are the second limit. The authors tied their findings to the amounts used in professional dishwashers, the machines in restaurants and institutions, which run shorter, hotter cycles than a home machine. The residue they measured came from those machines. The abstract reports no measurement of a household dishwasher, so the study does not say how much rinse aid a home machine leaves on a plate, or whether that amount matters.
Our reading is of the abstract PubMed publishes. The full paper is not open access, so a detail the abstract leaves out, such as which rinse aid products were tested, is not something we can report.
What a household reader can take from it
The study names an ingredient class, alcohol ethoxylates, and a mechanism, damage to the seal between gut lining cells. That is specific enough to act on in one way. A rinse aid’s ingredient list, on the brand’s own site or the label, is where an alcohol ethoxylate would appear, and it is now a line worth reading with a question in mind. Runlow does not yet carry product records for rinse aids, so we can’t tell you which ones list one. When we do, that fact will render from the record, the way every ingredient fact on this site does.
What the study does not license is a verdict about the bottle in your dishwasher. It did not test household machines or household exposure, and we won’t fill that gap with a guess in either direction. Rinse aid does one job, which is preventing the spots and film that our white film explainer covers, and whether that job is worth an ingredient the study flagged is a question the study leaves open.
Frequently asked questions
- Did the study find that rinse aid is harmful to people?
- No. It measured damage to human gut lining cells grown in the laboratory, in organoids and in a gut-on-a-chip model. No person was studied and no health outcome in a person was measured. The authors' background framing about chronic inflammatory disease is the hypothesis that motivated the work, not a finding of it.
- Does the study apply to a home dishwasher?
- The concentrations the authors tied their findings to are those used in professional dishwashers, and the residue they measured on dishware came from professional machines. The abstract reports no measurement of household dishwashers, so the study does not say what a home machine leaves behind.
- Which ingredient did the researchers identify?
- Alcohol ethoxylates, a class of surfactant. When the researchers tested the rinse aid's components one at a time, this class produced the strong toxic and barrier-damaging effect they had seen from the whole product.
- Should I stop using rinse aid?
- The study does not answer that for a household, and neither do we. It tells you which ingredient class the researchers identified and at what kind of concentration, which is enough to read a rinse aid's ingredient list with a specific question in mind.
