Under a new law, coming into force in 2014 under the Food Information for Consumers Regulation, firms will have to highlight potential allergen risks in a product's ingredients list in bold or a different background colour.
But the FSA is in discussion with the European Commission over concerns that consumers might not check the list. It wants signposts on pack to flag up the need for allergy sufferers to consult the label.
Jeff Rooker, outgoing chairman of the FSA, said it would be confusing and "dangerous" not to have consistent signposting. "This is not about asking for gold plating," he said. "This is about asking for information that saves people's lives."
Sue Hattersley, head of the Food Allergy Branch at the FSA, said the mandatory changes should make it easier for consumers to find this information quickly, "regardless of the product or manufacturer". She said it would also help standardise labelling across the industry, both in the UK and Europe."
However, these rules will not apply to precautionary warnings, such as the 'may contain' labels that indicate the potential risk of cross-contamination.
It is widely believed that the new regulation will result in many firms no longer using voluntary 'may contain' labels, forcing allergy sufferers to read full ingredients lists to see if they are at risk.
'Don't understand labelling'
René Crevel, science leader for allergy and immunology at Unilever, said: "There is pretty good evidence that consumers don't understand labelling. Statements should be concise and clear and backed by good science."
Hattersley added: "By April we will have guidance to compliance, so it will very clear to firms and consumers what they need to do."
However, Crevel feared moving away from the use of 'may contain' labels, because they alert the consumer to allergy risks that don't necessarily stem from an ingredient.
"We still need a way of conveying that there is a risk from the process [used to manufacture]," he said.
But Ray Boggiano, consultant at global security company Red24, argued 'may contain' labels were too vague and needed replacing.