A chemical commonly found in food and drink packaging has the potential to affect embryonic brain development, say US scientists.
The chemical, Bisphenol A, can be found in the lining of food and drink packaging, including some plastic bottles and in the lining of metal cans. It is used to protect against contamination and extend the content's shelf life.
Known as BPA, the chemical has also been found in some baby bottles. Last year the federal government announced a voluntary phase-out of BPA use in polycarbonate baby bottles.
Outlined in the journal Proceedings of the National Academy of Sciences on Tuesday, the study got pregnant mice to ingest the chemical and then studied the neurons from the offspring to establish the effect of BPA on brain development.
"Our study found that BPA may impair the development of the central nervous system," said neurologist and lead author Wolfgang Liedtke from Duke University. "[It] raises the question as to whether exposure could predispose animals and humans to neurodevelopmental disorders."
The chemical was capable of oppressing a gene vital to nerve cell function and to the development of the central nervous system. However local researchers said the amounts of BPA studied did not reflect normal consumption rates.
Neuroendocrinologist Wah Chin Boon from the Florey Institute of Neuroscience and Mental Health said the dosage used in the study was 20 times higher than the amount approved by Australian, New Zealand and American food standards bodies.
"The approved level is a lot higher than what someone would consume anyway, so it is very unlikely someone would consume that volume," Dr Boon said.
Australia, New Zealand and America have the same maximum consumption standard for BPA at 50 micrograms per kilogram of body weight per day.
The American study used 10 milligrams per kilogram per day.
"I don't think a person could consume that much," she said.
A senior lecturer at Adelaide University's faculty of medicine, Dr Ian Musgrave, agreed, saying while the research threw light on aspects of gene regulation, it was not relevant to human exposure to the chemical.
But Dr Boon said as a scientific study, it was useful to learn about the mechanisms at play because while BPA has been shown to affect the developing nervous system, little is known about how this occurs.
"This research shows that if the dose is high enough it can shut down the sodium channel, which is important for brain development" she said.
The chemical has raised questions before - mainly whether exposure to it can predispose people to a range of health problems including reproductive and immune system disorders, cancer and obesity.
Food Standards Australia New Zealand says an "extremely large amount" of food and drink would need to be consumed to even reach a tolerable daily intake for BPA.
A survey by consumer group Choice found that a nine-month old baby weighing nine kilograms would have to eat more than one kilogram of canned baby custard containing BPA each day to reach the tolerable level. And that was assuming the custard contained the highest level of the chemical.