Almost three-quarters of rice cakes and other rice-based foods aimed at babies and young children contain dangerously high levels of arsenic, which has been linked to health problems including cancer.The findings raise doubts about the effectiveness of EU rules brought in only last year designed to reduce the amount of the toxic chemical, which can impair a baby’s physical and mental development.

Dangerously high levels of inorganic arsenic are also often found in babies who have been reared on formula milks, especially non-dairy versions, according to the research from experts at Queen’s University Belfast.

“This research has shown direct evidence that babies are exposed to illegal levels of arsenic despite the EU regulation to specifically address the health challenge. Babies are particularly vulnerable to the damaging effects of arsenic that can prevent healthy development of a baby’s growth, IQ and immune system to name but a few,” said Andy Meharg, a professor of plant and soil sciences at Queen’s, who led the research.

“Products such as rice cakes and rice cereals are common in babies’ diets. This study found that almost three-quarters of baby crackers specifically marketed for children exceeded the maximum amount of arsenic,” he added.

In January 2016 the European commission introduced new rules setting out the legal maximum amount of inorganic arsenic that food manufacturers can put in rice and other rice products consumed by many children. However, Meharg and his co-authors have found out that the composition of rice-based snack foods has not become healthier despite that move.

“Little has changed since this law was passed and 50% of baby rice products still contain an illegal level of inorganic arsenic,” according to the study, which has been published in the journal Plos One.

Rice usually has 10 times more inorganic arsenic in it than other foods and overconsumption has been linked to developmental problems, diabetes, heart problems and nervous system damage.

The authors said there is “an urgent need” for food manufacturers to do more to cut the amount of arsenic in their products aimed at babies and children. Parents should seek out the rice products with the lowest arsenic content “in order to protect this vulnerable group”.

Meharg and colleagues based their findings on urine samples taken from 79 infants tested before and after they had been weaned, and on analysis of unnamed branded products of that type.

Food producers could reduce arsenic levels by as much as 85% by percolating the rice before using it, said Meharg. “Simple measures can be taken to dramatically reduce the arsenic in these products so there is no excuse for manufacturers to be selling baby food products with such harmful levels of this carcinogenic substance,” he said.

The Food Standards Agency urged parents not to give children aged between one and four-and-a-half rice drinks but offered no advice as to whether they should keep eating rice cakes and other foods.

“We recommend that consumers eat a balanced, varied and healthy diet. Rice and rice products can be part of that, including for young children. However, we do advise that toddlers and young children – ages one to four-and-a-half years – should not be given rice drinks as a substitute for breast milk, infant formula or cows’ milk. This is because of their proportionally higher milk consumption and lower bodyweight compared to other consumers,” said a spokeswoman.