What is dishwasher rinse aid?
And do you want it coating the things that come into contact with your food?
Somewhere along the housekeeping timeline, rinse aid entered the list of products that we’re supposed to be using to keep things clean. Oh, the shame of water spots on our glassware! Bottles of it line the supermarket shelf and many new dishwashers wink with a “feed me” alert when their rinse-aid compartments are depleted. But what is a rinse agent and do we really need it?
So, the basics: Rinse aid is a surfactant that reduces the surface tension of water. Surface tension is the “skin” effect on a droplet that makes it ball up rather than spread out on a surface. (Think of droplets of water on a leaf.) As a surfactant, rinse aid prevents water from forming into droplets and instead encourages it to drain from the surface in thin sheets. Thus, spots from dissolved minerals left behind from evaporated droplets are diminished.
Rinse aid doesn’t actually help in rinsing, rather, it zaps droplets and thus hastens drying and promotes shininess. But what kind of sorcery is behind this magic? That’s where things get a bit spotty, so to speak.
The healthy products watchdog, Environmental Working Group, rated 14 different rinse aids and delivered a grade of F to four of them and a D to five. An F ranking signifies the product is of “highest concern” and has poor ingredient disclosure or poses “potentially significant hazards to health or the environment.” Products earning a D are of high concern and pose “likely hazards to health or the environment.”
The ingredients that caused these rankings include:
- Sodium tripolyphosphate: High concern for general ecotoxicity.
- Methylchloroisothiazolinone: High concern. The US EPA reports the LC50 value is very toxic to aquatic life.
- Antiredeposition agent: Moderate concern for cancer, respiratory effects, kidney and urinary effects, general systemic/organ effects; and some concern for chronic aquatic toxicity, skin irritation/allergies/damage.
- Troclosene sodium, dihydrate: Moderate concern for chronic aquatic toxicity, acute aquatic toxicity, respiratory effects; some concern for general systemic/organ effects, developmental/endocrine/reproductive effects, cancer, kidney and urinary effects, nervous system effects, digestive system effects, skin irritation/allergies/damage, damage to vision.
- Oxybenzone: Moderate concern for developmental/endocrine/reproductive effects.
And other assorted ingredients, many of which were ranked for concern of potential skin irritation.
That said, three brands were given an A grade, meaning that EWG has no problem with them. Ecover Rinse Aid, Seventh Generation Rinse Aid Free & Clear, and Nature Clean Rinse Agent are all plant-based formulas and passed muster.
Many DIY advice-givers recommend using white vinegar, but while it might make your crockery corruscate, its high acidity can damage your dishwasher, especially any rubber parts in the rinse-aid cavity. And the thing is, you may not need rinse aid at all depending on the mineral make-up of your water (and personal preference). If you’re not seeing water spots and your dishwasher seems to be drying your dishes competently, just skip it altogether. It means one less thing to buy, one less bottle that has to be made and shipped, and that much more aquatic life not exposed to compounds that the EPA reports as toxic. Not to mention, fewer questionable chemicals coming into contact with your food.