Potential Risks of Commercial Dishwashers
According to researchers from the Swiss Institute of Allergy and Asthma Research working with organoids, residue from rinse agents on dishes after cleaning in professional-grade dishwashers can harm the natural protective layer in the gut and contribute to the development of chronic diseases
Commercial dishwashers are a convenient way to quickly clean and dry plates, glasses, and cutlery in various settings such as restaurants, schools, and barracks. However, a recent study conducted by researchers at the Swiss Institute of Allergy and Asthma Research (SIAF), an associated institute of the University of Zurich (UZH) has revealed that these appliances come with a risk. The study found that an ingredient in commercial rinse agents has a toxic effect on the gastrointestinal tract.
Chemical Residue on Clean Plates
A typical cycle in a commercial dishwasher involves circulating hot water and detergent for around 60 seconds at high pressure. Afterward, there is a second 60-second washing and drying cycle in which water and a rinse agent are applied. “What’s especially alarming is that in many appliances, there’s no additional wash cycle to remove the remaining rinse aid,” says Cezmi Akdis, UZH professor of experimental allergology and immunology and director of the SIAF, who led the study. “This means that potentially toxic substances remain on the dishes, where they then dry in place.” When the dishes are used the next time, this dried chemical residue can easily end up in the gastrointestinal tract.
This inspired the research team under Akdis 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.
Similar protective layers are also present on the skin and in the lungs. As numerous studies have shown, many additives and chemicals that we encounter in everyday life can damage these layers. “We assume that defective epithelial barriers play a role in triggering the onset of two billion chronic illnesses,” says Akdis. This connection is explained by the epithelial barrier hypothesis, which Akdis has helped develop during his more than 20 years of research in this field.
Toxic Substances in Rinse Agents
The researchers used a newly developed technology for their study – human intestinal organoids and intestinal cells on microchips. The tissue forms a three-dimensional clump of cells that is very similar to the intestinal epithelium in humans. The team used various biomolecular methods to analyze the effect that commercial detergents and rinse aids have on these cells. They diluted these substances to reflect the amounts that would be present on dry dishes (1:10,000 to 1:40,000).
The result was that high doses of rinse agents killed the intestinal epithelial cells and lower doses made it more permeable. Researchers also observed the activation of several genes and cell signaling proteins that could trigger inflammatory responses. A more detailed analysis showed that one component of the rinse agent – alcohol ethoxylates – was responsible for this reaction.
According to Akdis, these findings have significant implications for public health. “The effect that we found could mark the beginning of the destruction of the gut’s epithelial layer and trigger the onset of many chronic diseases,” he says. Akdis calls for an immediate response: “It is important to inform the public about this risk since alcohol ethoxylates seem to be commonly used in commercial dishwashers.”
Reference: “Gut epithelial barrier damage caused by dishwasher detergents and rinse aids” by Ismail Ogulur, Yagiz Pat, Tamer Aydin, Duygu Yazici, Beate Rückert, Yaqi Peng, Juno Kim, Urszula Radzikowska, Patrick Westermann, Milena Sokolowska, Raja Dhir, Mubeccel Akdis, Kari Nadeau and Cezmi A. Akdis, 1 December 2022, Journal of Allergy and Clinical Immunology.
DOI: 10.1016/j.jaci.2022.10.020
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18 Comments
I’ve been paranoid about this for years, leaving the rinse-aid out and wondering what detergents are left on the dishes with an extra rinse. There’s alcohol ethoxylates in residential dishwasher rinse aid too, in Jet-Dry and Finish. I can’t tell if it’s in Cascade since they don’t list ingredients. I didn’t see it in Fairy or Brillo or Seventh Generation.
A rinse cycle after the rinse agent would defeat the purpose, leaving those nasty calcium water spots again instead of gloriously spotless toxic chemicals.
This is very interesting and something that I have often worried about as we drink out of the glasses and eat off the plates. Is it just the rinse agent? I have never used a rinse agent because I’ve always been of the mindset, use the least amount of chemicals necessary to do the job. I also use 7th Generation pods…according to their package…”The Safer Choice”…so I guess that’s sort of admitting that it’s still not the best choice? I know one thing, I certainly don’t want to wash all the dishes by hand for our family of 6. I guess there is a price to pay for everything. Still glad I have never used the rinse agent. In this day and age one must really be choosy about what we are putting in and on our bodies and what we are using around the home. The wonderful thing is, the best cleaning products are water, elbow grease and vinegar! According to what I have read, you can use vinegar as a rinse agent in the dishwasher! Three cheers for going natural. Help you body and the planet.
Vinegar is a great cleaner. I’ve read where it’s great for the dishwasher. Other articles states that Vinegar can damage a dishwasher. I wonder which articles are actually correct?
Vinegar should never be used in any appliance dishwasher or washing machine. Vinegar is very damaging to the rubber hoses seals and eventually these will fail and the machine will start to leak.
How long you can get away with doing it before it breaks is anybody’s guess it can happen right away or it might take years.
For anyone who has been using vinegar and has not had a problem, consider yourself lucky.
Unfortunately manufacturers need to be more clear about this and they don’t always say so in the owners manual not to use it.
Sometimes the only mention about not to use vinegar is in the fine print in the warranty under the excluded items.
It’s usually pretty clearly states in that fine print that they will not cover the repairs even while under warranty for any damage as a result of vinegar.
The factory technicians that’s the first thing they look for if there’s a leak in the machine they will feel along the seals and the gaskets. All of those seals need to be flexible and move around and retain their shape and if they don’t if they are hard and they crack there’s only one thing that does that and it’s vinegar. They will make that report first thing in the notes and then your appliance company will refuse to pay for repairs.
Please elaborate.
I’ve always had the thought that dishwashers are probably not so safe. It’s bad enough the residues left on the dishes but all that product goes right into the environment and affects us there as well. We really need to start considering everything we use on a regular basis and realize it doesn’t just disappear after we use it..it affects us all. Extrapolate your families use out to the whole country, it’s massive.
The article is poor. It talks about commercial dish washers and doesn’t even bring up residential ones or talk about whether not using rinse aids in home dish washers would mitigate the effect (At least some detergent ‘pods’ have rinse aid built-in so perhaps it’s not as easy to be rid of it as you might first think). Would rinsing plates or glasses before using them help? The article says NADA about any such things. Was there a study on disease rates between those who manually wash dishes and eat mostly at home or take-out versus those who use a dishwasher or eat at restaurants that use them to compare disease rates? That’s not fool-proof, as home only may (or may not) be healthier living in general. Sadly, as it stands, it seems like a SCARE article designed to get clicks more than anything else.
Agreed… this story is incredibly confusing.
If you look at how much rinse water is used in our dishwashers it is no wonder the china etc is left with residues on. I hate the things and always wash and rinse everything in clean water.
I feel like things aren’t very clear here. Compare it to home dishwashers and not using rinse aids. Is it safer in home dishwashers compared to the commercial ones? Is regular dish detergent just as bad even with no rinse aid? This seems like either an incomplete study, or incomplete article on the study.
Hmmmm….. Better living through chemistry? Uh. Now I gotta add this to my list of things to be careful buying. Life is getting complicated.
“2 billion chronic diseases” is where i stopped reading, to go see if i could find anywhere how many chronic diseases are known in the medical community and couldn’t find anything to support that claim so it throws everything else out as being just as inaccurate. Ppl keep trivializing what can harm u, when the body fights off cancer causing entities every day, nothing is safe everything humans have created has a toxic effect on ourselves and the environment.
I agree, simply using common sense, that the article or the study(or both) is flawed in several ways leaving more questions than answers. Having thought of chemicals in not only rinse aids but the soap itself that gets built up on dishes from dishwashers make me think it’s certainly a concern and deserves much more trials and studies. My dishwasher leaves a strong soapy, chemical smell on dishes. But done by hand with mild soap with limited ingredients and HOT WATER they are odorless yet sanitized. MORE STUDIES MUST BE DONE!
I feel like I’ve only gotten enough information to be worried, but not enough information to do anything about it. Would the author please provide the names of the chemicals or “active ingredients” that are problematic so that readers can determine if our own detergents contain it? Even if they are used exclusively in detergents for commercial dishwashers, I would still want to know.
I realize that home dishwashers function differently than commercial ones, and perhaps they do a better job of rinsing, and maybe it’s not an issue.
Also, correct me if I’m wrong, but it seems that the headline is a bit misleading because it names commercial dishwashers, rather than the chemicals in the rinse aids.
If I were to discover the chemical ingredient in my own dishwashing detergent, or “pods,” could I just add an extra rinse cycle?
Or maybe just follow the washing cycle with a rinse under the kitchen faucet for just the eating utensils, which actually go in your mouth?
More information, please.
Thank you
t’s possible.
What’s worse are the operations without the dish machine, the third step to hand sanitizing is a sanitizing soak.
According to health department the rinse cycle shouldn’t be hot so that the chemicals don’t penetrate.
I think that there should be specifics on the type of dishwasher and does this apply to modern or older?
Annoying. So much to think about. It’s too much. But a good note . Spots are ok. If it’s clean with water temp/ isn’t that ok? I think that alone is ok with me. Dishwashers use less water than manual washing. I don’t care about spots. Sometimes I wash with reg dish soap and put in dishwasher. Maybe they do
Maybe they don’t need more soap? Just rinse with reg dish soap and them dishwasher with hot water is good enough.
Abs. STUNNED and THANKFUL, that （knock on wood）your website doesn’t have a pop-up trying to sign us up, to garbage we don’t want or need. So please, subscribe me. The article I just read was MOST interesting and informative.
Use a combination of baking soda and borax as your dish detergent and avoid the chemicals.