CleanTok Says Dishwasher Rinse Aid Causes IBS. Actually, That's False.

New York Times

07-07-2025

Rinse aid is a liquid that can be added to a dishwasher to help prevent water spots on glassware, which are especially persistent if you have hard water. You add the rinse aid to a compartment in your dishwasher about once a month, and the rinse aid dispenses in small amounts (usually around 3 to 5 mL) toward the end of each wash cycle. The rinse aid compartment is often located near the detergent dispenser in your dishwasher door. Andrea Barnes/NYT Wirecutter
Rinse aid contains surfactants, or surface active agents. When rinse aid meets water, these surfactants break water tension, allowing droplets of water to sheet off dishes and glassware. This expedites drying and helps glassware dry without spots.
Rinse aid also aids in drying, picking up some of the slack from the machine's drying system, which can help save time and energy usage in a typical dishwasher cycle. The mug and bowl on the left were dipped in food coloring and water, while the mug and bowl on the right were dipped in the same solution with a half teaspoon of rinse aid added. Andrea Barnes/NYT Wirecutter The bowl on the left was dipped in a solution of water and food coloring. The bowl on the right was dipped in the same solution with a teaspoon of rinse aid added. The rinse aid helps water glide off surfaces, leaving the bowl on the right with fewer water droplets. Andrea Barnes/NYT Wirecutter The mug and bowl on the left were dipped in food coloring and water, while the mug and bowl on the right were dipped in the same solution with a half teaspoon of rinse aid added. Andrea Barnes/NYT Wirecutter
The study making the rounds online was published in 2022 in The Journal of Allergy and Clinical Immunology, a peer-reviewed journal. Scientists at the Swiss Institute of Allergy and Asthma Research (SIAF), part of the University of Zurich in Switzerland, wanted to explore how common dish cleaning products might impact the gut. Specifically, they were interested in epithelial cells, the cells lining the intestines, which are thought to be a key component of the immune system's defenses.
Researchers washed dishes in both commercial and residential dishwashers and then examined them for residue. They then directly exposed epithelial cells in vitro (outside of the body) to various dilutions of professional rinse aid and other detergents in water to see how they responded. Professional rinse aid was shown to impair epithelial cells after being exposed for 24 continuous hours, and the study pinpointed alcohol ethoxylates as the main culprit.
The study found that cups washed in household dishwashers had undetectable concentrations of detergent, context that social media posts often fail to mention. Instead, the findings being highlighted on social media are from studying residue on dishes washed in commercial dishwashers with professional rinse aid.
Here's the catch: professional rinse aid is highly concentrated and meant for use in commercial dishwashers. It isn't rinsed as thoroughly, due to the speed at which dishes must be washed. Commercial kitchens need to sanitize dishes quickly to satisfy health department requirements, and dishes must be dried quickly to keep up with demand. Professional rinse aid makes quick drying possible.
Household dishwashers, on the other hand, have longer cycles and a final rinse of clean water. The rinse aid used in homes is also less concentrated. Because of this, the likelihood of similar amounts of alcohol ethoxylates remaining on your dishes at home is far lower than what might happen in the commercial settings that the experiment was studying. This is a commercial dishwasher, which is meant to wash dishes much faster than a typical household dishwasher. Andrea Barnes/NYT Wirecutter
But whether the dishwasher is commercial or residential, the rinse aid dilutions used in this study do not reflect a manufacturer's recommended use, noted Joseph Zagorski, a toxicologist and associate professor at the Center for Research on Ingredient Safety, a toxicology research center at Michigan State University. 'When used as directed, with the proper dilution, alcohol ethoxylates are considered safe for use. The referenced paper uses dilutions that are outside of the manufacturer's requirements,' said Zagorski.
But what if a small amount of rinse aid did manage to make it onto your glass and you accidentally ingested it? Would it reach the protective barrier of your intestines?
'The odds are pretty stacked against it,' said Thomas Wallach, MD, chief of pediatric gastroenterology at SUNY Downstate, whose research focuses on the gut's epithelial barrier. (Epithelial cells are cells on the surfaces of the body, such as skin and the inside of your intestines. )
At the very least, it's unlikely to occur at the concentrations of alcohol ethoxylates reflected in the study.
Here's why: For a person's epithelial cells in their intestines to be exposed to the level of rinse aid described in the study, not only would there need to be an unusually large amount of rinse aid left on their dishes, but trace amounts of previously dried rinse aid would then need to make it through saliva, the esophagus, and then the stomach and its enzymes and acids, before finally reaching the intestines. There, it would need to penetrate the gut's mucus barrier, which Wallach described to me as highly unlikely.
Emerging research studies like this one are designed to highlight subject areas where more research (and funding) is justified, said Wallach. 'I would look at this as the beginning of a process,' he said about the 2022 rinse aid study. 'I would definitely not consider this a conclusion.'
I have celiac disease, an autoimmune disorder that affects the small intestine, and I often wonder what might have triggered the gene lurking in my body. Was it a viral illness, an allergic reaction, or perhaps chronic exposure to a chemical or contaminant? I, and the medical establishment, don't know. And that's what's tricky about studies like this one. They pose more questions than they answer, and that's the point: These studies are designed to show areas we should continue to explore.
Hopefully you're not still worrying about using rinse aid, but if you're wondering about alcohol-ethoxylate-free alternatives, you have options.
Not all rinse aids are formulated with alcohol ethoxylates. Though we don't recommend a specific rinse aid at Wirecutter, in my own home, I use Ecover Rinse Aid, which is citric-acid-based and happens to contain no alcohol ethoxylates.
This alcohol-ethoxylate-free rinse aid leaves streak-free dishes and spot-free glassware. But it's among the pricier rinse aids available.
If you're concerned about rinse aid agents in some dishwasher detergent pods, these agents are formulated to be rinsed off by the final cycle. But if you prefer to avoid them altogether, you can switch to either of our powder detergent picks, Cascade Complete Powder or Dirty Labs 2-in-1 Bio Enzyme Dishwasher Detergent + Booster, which don't contain rinse aid.
And of course, if you don't mind spots on your glasses, you can forgo using rinse aid altogether.
This powder detergent is free of dyes, allergenic fragrance, PVA/PVOH, and plastic packaging. It cleans very well, but it falls short on grease and glassware, and it's the most expensive powder we tested.
This affordable and powerful powder detergent wipes away baked-on and greasy foods, but you may need to use more than the recommended dose to get the best results.
Some people recommend vinegar as an alternative to rinse aid. Vinegar will likely help prevent mineral deposits on glassware, but at Wirecutter, we don't recommend the prolonged use of vinegar in your dishwasher. Ongoing exposure to the highly acidic liquid could eventually cause issues with internal components of the machine. Rinse aid is a safer, more effective bet.
If this entire study has you wondering what simple ingredient swaps you might be able to make for dishwasher detergent, too, I cannot emphasize this enough: I do not recommend making your own dishwasher detergent, for safety concerns as well as effectiveness. A vintage ad for Cascade detergent shows that the desire for spot-free glass solutions has been around for some time. Photo courtesy of Procter & Gamble Heritage Center & Archives.
Unlike your average DIY dishwasher detergent recipe, the dishwasher detergents we recommend are designed by chemists and other cleaning experts. This year, I toured Procter & Gamble's dishwasher detergent testing labs and saw firsthand the level to which products are tested and researched for both safety and efficacy. Conversely, many DIY dishwasher detergent recipes call for borax, or sodium borate, a cleaning agent that is banned in the European Union and can cause potential harm if ingested.
Besides the possible safety concerns, DIY dishwasher detergent just isn't that effective. We mixed DIY dishwasher detergent in-house for our dishwasher detergent guide using washing soda, borax, and citric acid; it made me sneeze repeatedly, and within a month or two it had caked into a solid brick that we couldn't break open. (We ended up using water to dissolve it.) It also did not clean dishes very well, especially when compared with our two powder detergent picks.
I love a satisfying CleanTok as much as the next person (rug restoration, anyone?), but I have learned to think twice when a talking head tells me to be scared of a common cleaning product. It would be awesome if you could cure gastrointestinal issues by swapping out cleaning products, but is anything ever that simple? Based on what we know now, the answer is no — so I happily continue to use rinse aid.
This article was edited by Katie Okamoto and Megan Beauchamp. Dishwashers save water, time, and energy. Here are some tips for getting the most out of your machine.
Dishwasher detergents are better than ever, and after testing over 30 of them, we've found that Cascade Free & Clear ActionPacs deliver the best overall clean.
Inexpensive doesn't necessarily mean bad. Cascade Complete Powder costs just pennies per load and is the best powdered dishwasher detergent we've tested.
What I Cover
I research and report on dishwashers, washing machines, dryers, and laundry. This involves touring factories, visiting showrooms, attending trade shows, speaking with appliance-brand representatives, interviewing experts, studying patents and schematics, and reading manuals. I am based in New York City, and I test appliances in our Long Island City office.