Rinse aid is one of those products that you pour into the dishwasher almost without thinking, convinced that it only serves to make plates and glasses shinier. In reality it has a precise technical role and, as recent studies have shown, it can leave chemical residues on dishes that end up directly in our body.
Because you really use rinse aid
Does not shine, does not smell, does not degrease. Rinse aid acts on water: it lowers its surface tension, so that it slides off dishes without leaving drops or streaks. It is especially useful in areas with hard water, where limestone ruins glasses and cutlery, while in areas with soft water its absence can go almost unnoticed.
Its use is therefore practical, not aesthetic. But this is only part of the story.
Chemical residues remain on the dishes
A study by the Swiss Institute of Allergy and Asthma Research (SIAF), connected to the University of Zurich, has highlighted a detail ignored by many: rinse aids, particularly those with ethoxylated alcohols, do not disappear completely after washing. They can stick to dishes and end up in food.
“These chemical residues easily end up in the gastrointestinal tract during subsequent use of the dishes, putting the health of those who consume food on them at risk.”
— Cezmi Akdis, SIAF director
In professional dishwashers the risk is higher
The Swiss study examined commercial dishwashers, such as those found in canteens and restaurants. They work with very rapid cycles: one minute to wash with hot water and detergent, another to apply rinse aid. Often there is no real final rinse, and residues remain on the dishes.
Plates and glasses come out clean to sight, but invisibly contaminated.
Alcohol ethoxylates: what they do to the intestine
The researchers exposed human intestinal organoids and cells on microchips to concentrations similar to those found on washed dishes. The results are worrying:
Damage to the intestinal barrier has been linked to an increased risk of allergies, gastritis, obesity and even neurological disorders such as multiple sclerosis and Alzheimer’s. It is an important confirmation of the “epithelial barrier” hypothesis, according to which everyday chemicals can pave the way for systemic diseases.
At home the situation is different, but not without risks
Domestic dishwashers, thanks to longer rinses, eliminate residues better than professional ones, but do not eliminate them completely. If the machine is old, the cycle is too rapid or the dose of rinse aid is excessive, some of the substances still remain stuck to the dishes.
Many never adjust the dispenser wheel, others replace the product with vinegar thinking they are making a “green” choice, but vinegar is not designed to resist high temperatures and over time can damage the seals.
How to really reduce waste
Experts suggest some practical solutions:
In professional kitchens it would be necessary to introduce additional rinsing and stricter controls on chemical residues, but at a domestic level the difference is made by daily choices.
It is not to be demonized, but should be used with awareness
Rinse aid is useful and does its job, but it is not neutral. Using it blindly, ignoring dosages and composition, means accepting the risk of ingesting small quantities of chemicals every day. It’s not alarmism, it’s simple reality demonstrated by scientific studies.
The key is not to eliminate it out of fear, but to manage it wisely: choose better products, adapt its use to your context and not treat it as an insignificant detail. Behind a perfectly transparent glass there can be more than meets the eye.
