Now a British Government study is expected to confirm a link between the chemicals and temper tantrums, poor concentration, asthma and rashes.
The research funded by the Food Standards Agency focuses on six artificial colours and one preservative.
These are used in thosands of soft drinks, sweets, biscuits, cake and processed foods found on supermarket shelves.
Though the results have not yet been released, experts are already warning parents to keep their children away from these products.
This has potentially explosive consequences for manufacturers, who may need to reformulate many products.
The FSA refused to comment until the research has been published. The results will be published in a scientific journal after peer reviews.
From the May 23, 2007, Prepared Foods e-Flash