If you’re like most Australians, your dishwasher is a trusty sidekick in the kitchen—saving you time, elbow grease, and the dreaded after-dinner squabble over who’s on washing-up duty.
But what if we told you that some of the most common items you pop in your dishwasher could be causing a hidden—and rather disturbing—problem, not just for your machine, but for the environment and even your own health?
A recent Australian study from the University of Queensland has shone a spotlight on a surprisingly sneaky source of plastic pollution: your dishwasher.
Researchers found that running a full load of plastic containers and utensils can shed a staggering 920,000 tiny plastic fragments into the water during just one wash cycle. That’s nearly a million microscopic pieces swirling down the drain every time you hit ‘start’—and it all adds up.
The five offenders: What’s lurking in your kitchen?
The study, led by research fellow Dr Elvis Okoffo, focused on five types of plastics commonly found in household kitchenware:
- Polypropylene (PP)
- Polyethylene (PE)
- Polystyrene (PS)
- Nylon
- Polyethylene terephthalate (PET)
These are the plastics that make up everything from your favourite takeaway containers to those handy reusable water bottles and even some utensils. The verdict? Dr Okoffo’s advice is clear: if you want to cut down on plastic pollution, avoid putting any plastic items in your dishwasher altogether.
How big is the problem?
You might be thinking, ‘Surely a few plastic bits here and there can’t hurt?’ But the numbers are eye-opening.
While a single household dishwasher might only shed the equivalent of a rice grain’s worth of plastic each year, that still adds up to around 33 million particles being flushed into wastewater annually from just one home.
Multiply that by millions of households, and you start to see the scale of the issue.
Dr Okoffo points out that while dishwashers are a significant source of these plastic particles, their overall mass contribution to plastic pollution is still minor compared to other sources, like synthetic clothing in washing machines.
However, the sheer number of particles is what’s concerning—especially since these microplastics are so tiny, they’re almost impossible to filter out completely.
Avoiding these materials could lengthen your dishwasher’s lifespan. Image source: Photo by Mohammad Esmaili on Unsplash
Where do all these plastics go?
You might be relieved to know that most of the plastic particles in wastewater are captured before they reach the ocean. But that’s not the end of the story.
Many of these particles are repurposed as biosolids—treated sewage that’s spread on farmland and used as landscape topsoil.
Dr Okoffo’s previous research estimated that 4,700 metric tons of plastic particles enter the Australian environment as biosolids each year, with 3,700 metric tons ending up on agricultural land.
‘When you apply it to agricultural land, that’s when it becomes a problem,’ Dr Okoffo warns. These plastics can be absorbed by plants, eaten by animals, and eventually make their way back to us—a full circle that’s more than a little unsettling.
Why should we care?
It’s not just an environmental issue. Recent studies have found that humans, animals, and plants are all absorbing worrying amounts of these tiny plastic particles.
In fact, a study published in February revealed that our brains can contain as much as a spoonful of microplastics.
The long-term health effects are still being studied, but early research suggests links to inflammation, hormone disruption, and even neurological issues.
What can be done?
Dr Okoffo’s earlier work on microfibres from washing machines has already prompted calls for manufacturers to install filters to catch these particles.
He believes it’s time for similar technology to be added to dishwashers. In the meantime, the best thing you can do is to avoid putting plastic items in your dishwasher.
Opt for glass, ceramic, or stainless steel alternatives where possible, and hand-wash plastics if you must use them.
Tips for a cleaner, greener wash:
Switch to non-plastic kitchenware: Glass, stainless steel, and ceramic are all dishwasher-safe and don’t shed microplastics.
Hand-wash plastics: If you must use plastic containers, wash them by hand with gentle soap and cool water.
Check your dishwasher’s filter: Clean it regularly to help trap any particles before they enter the wastewater.
Support innovation: Look for dishwashers with built-in microplastic filters as they become available.
Our dishwashers may be making life easier, but they’re also quietly contributing to a growing environmental and health concern. By making a few simple changes in our kitchens, we can help reduce the flow of microplastics into our waterways, our food, and ultimately, ourselves.
Have you noticed your plastic containers looking a bit worse for wear after a few cycles? Do you have any tips for reducing plastic use in the kitchen? We’d love to hear your thoughts and experiences—share your stories in the comments below!
Also read: An unseen threat might be lurking in your home appliance! Here’s how to keep your family safe
