Experts are calling on the government to take action after new research showed some types of baby formula contain 100 times more aluminium than breast milk.
A team led by Professor Chris Exley at Keele University found at least twice the amount of aluminium in formula as is allowed in tap water, which they said could pose risks to health.
Top brands including Aptamil, Cow and Gate and Hipp Organic all contained levels of aluminium tare too high, the researchers said.
Their study, published in the journal BMC Pediatrics, examined 30 types of formula sold in the UK, including infant first milks and toddler milks.
It follows on from research published by the team three years ago highlighting the potential dangers of aluminium in formula.
Prof Exley said: “We know an awful lot about aluminium but we don’t know an awful lot about how it impacts on human health.
“People have almost certainly heard about the link with Alzheimer’s disease and other neurological conditions and we know from studies that it influences the way in which bones form.
“Aluminium can also produce anaemia in individuals, which is not then helped by giving people more iron.
“How may this aluminium be impacting on the immediate and long-term health of the baby - these are questions that are still unanswered.
“What we don’t know is whether aluminium is accumulating in the bodies of formula-fed babies. If it is, aluminium has no biological function at all, you have no requirement for it.
“Simply the fact we don’t have experiments showing that it’s either safe or not safe in humans certainly doesn’t mean it’s not an issue.”
Prof Exley accused formula milk manufacturers of complacency over the issue and said it was time for the government to take steps to issue limits on aluminium in formula.
Some formulas have amounts of aluminium 100 times higher than the same amount of breast milk, he said.
“We believe this is too much aluminium to be subjecting a human to at their most vulnerable stage of life.
“Manufacturers have done absolutely nothing, no attempt to address this whatsoever.
“They are complacent because they don’t have to do anything about it.
“We expected something to be done about this since our last research but, if anything, the amount of aluminium in packaging has increased.”
Prof Exley said it was unclear how the aluminium was getting into the milk.
“There’s a very good chance that some of this aluminium is coming from the packaging and an equal chance it is in the ingredients. Processing is also likely to be a source.”
The study involved both ready-to-drink formulas and powdered varieties - all 30 types were found to contain aluminium.
Results showed both ready-to-drink and powdered varieties had a similar concentration of aluminium overall, but it was highest in soya-based milks.
Among ready-to-drink types, SMA toddler milk had the lowest concentration, followed by Hipp Organic first infant milk, Aptamil hungry baby milk, SMA first infant milk and Aptamil first milk.
The growing up milks produced by Cow and Gate and Aptamil had the highest concentrations, with Aptamil toddler milk having almost three times as much aluminium as SMA toddler milk.
For powdered milks, Hipp Organic growing up milk had the lowest level, followed by Aptamil hungry, Aptamil first milk and Hipp Organic follow-on milk.
At the other end of the scale, soya-based formulations had the highest concentrations of aluminium but SMA toddler milk and Hipp Organic first infant milk also had high levels.
Prof Exley added: “Clearly the manufacturers of infant formulas are not concerned about reducing their content of aluminium and the extensive use of aluminium-based packaging for infant formulas seems to confirm this.”