Manufacturers have been ordered to ensure that the contamination is reduced.

The Ministry of Agriculture, Fisheries and Food (MAFF) responded to reports from two independent expert advisory committees that found 66 of 137 samples of baby food from glass bottles contained the chemical, epoxidised soya bean oil or ESBO.

However, ESBO is only dangerous in large quantities and the MAFF said there was no "immediate health risk".

Baby food companies are already acting to reduce the amount of ESBO used in their products and the MAFF told them to continue with the work.

High levels

ESBO is used on jars to prevent contamination from bacteria or anything else by creating an airtight seal, and it helps make signs of tampering more obvious.

A Swedish study earlier this year found that ESBO levels of up to 105mg per kilogram were seeping into baby food.

Another study, by the Joint Food Safety and Standards Group (JFSSG), found 48% of its sample was contaminated to the same degree.

The UK Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment recommends a maximum daily intake of one milligram per kilogram of body mass.

It, along with the Food Advisory Committee, has examined the studies and passed on its conclusions to the MAFF.

A spokesman for the ministry said: "The committees have concluded that although the findings do not indicate any immediate health risk, it would be prudent for action to be taken to reduce ESBO levels in baby foods packaged in glass jars.

"The JFSSG accepts this advice, and is today telling industry to continue with its action to reduce ESBO levels in glass jars."

Safety measures

Dr Nigel Dickie, a nutrition consultant for Heinz welcomed the findings as it put the company in the clear.

"The data from the study show that in Heinz varieties, ESBO was either not detected or so low as not to be quantified," he told BBC News Online. "It is not a problem for us but we continue to take it seriously.

He said there is a crucial stage in the cooking process when contamination could occur.

"We make sure that the food does not come into contact with the cap at that crucial stage."