Are you a religious fresh produce washer, or do you give your broccoli more of a cursory splash? Or maybe you don't bother at all.
Testing recently uncovered the presence of a banned chemical called thiometon in fresh berries sold in New South Wales. High levels of another legal pesticide were also detected during this testing.
On some blueberry samples, the levels of the legal pesticide, dimethoate, were within the legal residue limits but still high enough that both children and adults could exceed the acceptable daily intake (ADI) by eating less than a standard 125g punnet.
With this in mind, we wondered how effective washing fruit and veggies was at removing chemicals and reducing the amount we consume.
Can pesticides be washed off fruits and veggies?
Julian Cox is an associate professor of food microbiology at the University of New South Wales and a member of the Food Safety Information Council board.
Dr Cox says washing fresh produce "reduces risks in all sorts of ways".
"Any washing will mitigate risk … and simply the physical act of washing will help move material from the surface, be it bugs, be it soil, be it chemical residues."
Some produce is easier to wash than others, Dr Cox says.
"With something like raspberries — softer fruits — you really can't do too much with them in terms of physical action."
He says this is why a lot of fruit and vegetables sold commercially are washed before sale using a food-grade cleaning solution with an ingredient such as chlorine.
Food and nutrition scientist Emma Beckett, based in Newcastle/Awabakal, says she cleans raspberries by dunking them into a mixture of vinegar and water.
She says it doesn't negatively impact the flavour at all.
Dr Beckett also advises washing your hands before washing your fresh produce.
"Otherwise, you're washing what's on your hand onto the thing you think you're washing."
Jian Zhao is also an associate professor at the University of New South Wales, whose research areas fall within food science and technology.
He says washing fresh produce does reduce your risk of chemical intake, particularly with the help of baking soda.
Dr Zhao says this is because baking soda is an "alkaline substance" that will "accelerate the breakdown of certain types of chemical residue".
If the produce is smooth-skinned, he says running water with some rubbing is probably enough, but for harder-to-clean produce, he recommends soaking them in water with some salt or baking soda for about 10 minutes.
How is pesticide use controlled in Australia?
A spokesperson from Food Standards Australia New Zealand (FSANZ) — which sets out the legal requirements for food produced and sold in Australia — says it "undertakes periodic safety checks for chemicals of public health concern".
The spokesperson says the Australian Pesticides and Veterinary Medicines Authority (APVMA) registers and approves chemical uses and sets maximum residue limits (MRLs).
The spokesperson says these are "set well below the level that could pose health and safety risks to consumers".
The ABC's Background Briefing found residue testing happens every 4–6 years nationally, and it's largely focused on exports.
Following the investigation, the APVMA announced a review into the use of dimethoate on blueberries, raspberries and blackberries as "new information" revealed Australians were eating "significantly more berries" than when it had last reviewed the use of dimethoate in 2017.
Do pesticides get absorbed into fruit and veggies?
Dr Zhao says, "fruit and vegetables do absorb a small amount of pesticides, which is considered as part of the [MRLs]".
Dr Beckett says that "some pesticides are incorporated into the structures of the plants, and others sit on the outside of the plant as a barrier".
This impacts the usage limits and rules around when this product can be used in relation to when it is harvested (the withholding period), she explains.
According to FSANZ, "Where a chemical specifies a withholding period or pre-harvest time between application and harvest, these directions must be followed. In this way, any residues left on the produce should meet the MRL requirements."
Dr Beckett says if concern about chemical residue "became a reason for people to eat fewer fruits and vegetables, that would be really sad" because we're already not getting enough of them.
Editor's note 16/9/25: This story has been updated to include more information about residue testing in Australia.
