What's the problem?

Research has found some phthalates produce toxic effects in animals, particularly reproductive defects. Infertility, decreased sperm count and other reproductive abnormalities in male animals have been reported. These effects have been dubbed "the phthalate syndrome".

There's limited data on the health effects on humans but a recent report by the US National Research Council (NRC) says there's evidence showing widespread human exposure to phthalates at all stages of life. This exposure can be by ingestion, inhalation, or absorption through the skin. The NRC has called for an assessment of the cumulative risks of exposure to these and other chemicals that are linked to reproductive defects.

There are also unanswered questions about epoxidised soy bean oil (ESBO), particularly its use in the lid seals of glass jars. While ESBO itself is not considered harmful, it's known to generate potentially toxic derivatives that can migrate into foods. As yet, not all ESBO derivatives have been identified and there's a lack of good data about the long-term safety of those that have been.

What research does tell us is that ESBO dissolves in fats and oils and that there may be higher levels of the substance - and hence its derivatives - in fatty foods.

Under the lid

What's under the lid?

The Australian consumer organisation Choice recently tested 25 foods in glass jars for plasticiser residues. Products tested included a range of pasta and stir-fry sauces, pickles and preserves, many of which are found here. Most had a fat content of four percent or higher.

Nine of the products contained the plasticiser ESBO at levels well above those set by the EU. One product (a pasta sauce with 26 percent fat) had concentrations 14 times the EU limit.

Food Standards Australia New Zealand carried out a preliminary risk-assessment of Choice's test results. It concluded that consumption of the products is unlikely to pose an "immediate health risk". However, Choice remains concerned about the long-term health implications of plasticisers migrating into foods. We do too.

Choice approached manufacturers of the products it tested for a response to the results. One company, Heinz, voluntarily withdrew two products pending further investigation. Two other companies, Leggo's and Riviana Foods, said they'd follow up the issue with suppliers.