Fresh bread, takeaway hamburgers and meat pizzas are some of the foods the national regulator has found contain hormone-disrupting chemicals that have leached from plastic packaging, a report reveals.
Food Standards Australia New Zealand has detected two types of phthalates, or plastic softeners, in samples of popular foods at amounts exceeding international safety limits, triggering plans for further research.
What are phthalates doing in our food?
Food Standards Australia New Zealand has detected worrying levels of phthalates in some samples of food. Should consumers be concerned?
Overall, it said, chemicals that have migrated from packaging into food are a low risk to public health and safety.
It found that four out of six takeaway hamburgers tested for the phthalate DEHP contained between 67 and 180 per cent more than the amount permitted under European Union laws to be released from packaging into food, which is 1.5 milligrams a kilogram.
It reported one sample of fresh, savoury, "fancy" bread contained 347 per cent more than the limit.
And in samples tested for the phthalate DINP, Food Standards found a takeaway hamburger sample had 14mg a kilo and a pizza topped with meat and vegetables had 16mg a kilo - both exceeding "tolerable daily intake" levels.
"Consuming 0.6kg of either of these foods daily would be sufficient to reach the [tolerable daily intake]," the report said.
In animal studies DEHP has been linked with testicular toxicity in rats while DINP has been shown to affect the liver and kidney in rats, the report says.
Overall, Food Standards found half of the 30 chemicals it tested for, including bisphenol A (BPA), epoxidised soybean oil (ESBO) and phthalates, were at detectable levels "above the limit of reporting".
Steve McCutcheon, Food Standards chief executive, said the Australian Total Diet Study into chemical migration from packaging into food detected very low residues of some chemicals in a small number of samples.
"After undertaking a very conservative safety assessment on these very low levels, FSANZ has concluded there are no safety concerns," he said.
"The screening study identified that further work was required for two of the chemicals tested for [phthalates] and FSANZ will be sampling a wider range of foods for these chemicals so a full dietary exposure assessment can be undertaken."
Phthalates (pronounced with a silent 'ph'), or plasticisers, are also used in various solvents, coatings and adhesives. They can be found in PVC tubing, gaskets, cling wraps, printing inks, paper and cardboard packaging and laminated aluminium foil.
Experts have urged pregnant women to avoid phthalates after a University of Michigan study published in the medical journal JAMA Pediatrics found increased levels of some phthalates in urine during pregnancy correlated with higher odds of premature birth.
Catherine Itman, a research lecturer in physiology at the University of the Sunshine Coast, said Food Standards' results were "potentially concerning", considering the conclusions of various animal studies.
"However, we must recognise firstly that we are exposed to phthalates from many different sources, so it must be considered whether the phthalates present in some foods do substantially contribute to our overall phthalate exposure," she said.
"Secondly, we actually have very little direct information about the human health impacts of phthalates, as most toxicology studies have been performed using concentrations that do not reflect typical exposure levels and our knowledge of the effects of exposure to combinations of phthalates or phthalates plus other chemicals is wholly inadequate," she said.
"Until more is known, we should be be cautious with regard to how much phthalate exposure we consider to be acceptable."
Dr Itman, who also holds a conjoint appointment at the University of Newcastle, said until more studies were done, it would be wise to be cautious. She also questioned whether Food Standards' "watching brief" was sufficient.
Ian Musgrave, a senior pharmacology lecturer at the University of Adelaide, said in regards to DEHP and DINP, further studies would be undertaken as well as consultation with industry to ensure reduced levels.
"Even so, the risks identified were low. In the case of DINP, out of 48 foods tested, high levels were found in a single sample of peanut butter, one hamburger and one pizza," he said.
"You would need to consume 200g of that peanut butter or 0.6kg of that pizza daily to exceed the tolerable daily intake level."
In Australia, the onus for the safety of food contact materials is on manufacturers and retailers. Regulations are much stricter in the United States, the European Union and Canada.
Professor Ian Rae, honorary professorial fellow at the University of Melbourne, said the levels of packaging chemicals in Australian foods were shown to be very low by international standards and mostly below levels of concern set by the European Union.
"Canny manufacturers can see the way the winds are blowing. They are seeking alternatives, but we are not there yet and of course there are some laggards," he said.
"Although it's not always easy to replace a custom-designed chemical, experience shows that it's usually possible, even if a small cost increase is involved."
In 2014, Fairfax Media reported that 80 per cent of food and packaging companies surveyed by Food Standards said packaging rules under the code were "inadequate", "minimalistic at best" and "largely irrelevant", sparking fears among public safety advocates.