Article: published on 15 September 2025

Headlines in recent days have claimed dishwashers could be leaking toxic chemicals into your bloodstream. But is there any truth to it, or is this another example of unnecessary health fear-mongering? Dr Punam joined BBC Morning Live to set the record straight.

Much of the worry has been sparked by TikTok videos, with some racking up millions of views. They claim residue left on plates by dishwasher tablets could trigger inflammation, food intolerances, and even autoimmune conditions. The worry is that chemicals left behind on plates are then consumed.

These claims have leaned on a 2023 study in the Journal of Allergy and Clinical Immunology, which suggested that certain chemicals designed to prevent streaks and spots on dishes might damage stomach lining cells, potentially allowing toxins and bacteria to "leak" into the body. But experts have since challenged the findings, pointing out that the concentrations tested were far higher than anyone would encounter in real life. One experiment used levels more than 300 times stronger than typical exposure, while even the lowest concentrations tested were still double what you'd get at home.

Dishwasher tablets do contain chemicals that can be toxic in high doses. This is why manufacturers warn to keep them away from children and seek medical advice if they are swallowed. Some ingredients can also irritate skin. But when used as intended, dishwashers dilute these chemicals so they pose little risk.

In fact, dishwashers and tablets serve an important role: removing grease and bacteria that, if left behind, could cause food poisoning. At present, there is little evidence to suggest that long-term exposure to the chemicals in dishwasher pods is harmful, though more research is needed. If you are concerned, you could give dishes an extra rinse with water or choose eco-friendly tablets made with fewer chemicals, although these are often more expensive.

For context, washing-up liquid isn't worse or better than dishwasher pods at cleaning, they are simply formulated differently. Pods are made for machines, with enzymes and low-suds detergents, while washing-up liquid is designed for hand use and relies on foaming bubbles to cut through grease.

Morning Live regular Greg Foot also explored the topic in detail for his BBC Radio 4 podcast Sliced Bread, which you can listen back to on BBC Sounds.

Punam says:

"Keeping your dishwasher itself clean is just as important as washing the dishes. Leftover food and grime can build up, creating the perfect environment for bacteria and mould. You can buy specialist cleaners from the supermarket, but simple tricks also help. Adding a lemon in a mesh bag into the machine makes use of citric acid to break down gunk and remove odours.

It is also worth cleaning the filter regularly, as well as wiping down the drawers and the compartment where the tablet goes. Even how you stack your dishwasher matters, as poor stacking can make it less effective and stop it draining properly."

Always refer to manufacturers instructions when cleaning appliances.

Check out Consumer Journalist Harry Kind's tips on how to stack your dishwasher below

Sponges, often used for hand-washing dishes, are another concern.

Warm, damp, and full of food particles, they provide ideal conditions for bacteria. A 2017 study identified 362 species of microbes in kitchen sponges, with densities reaching up to 54 billion per square centimetre. Yet another study found that only a small proportion of sponges contained harmful bacteria, and even then, the amounts were low.

In other words, sponges are packed with microbes, but most are harmless. To keep them hygienic, replace sponges weekly, or clean them in boiling water with disinfectant. Avoid leaving them in the sink, and squeeze out food and moisture after each use. Alternatively, brushes can be a cleaner option since they dry more quickly and are easier to wash.

Eco-friendly washing-up liquids are also available if you prefer to cut down on chemicals when cleaning by hand.

So, are dishwashers dangerous to your health? The evidence suggests not, as long as you use them properly and keep your machine clean.