Fresh health fears over caramel colouring used in fizzy drinks, including Coca Cola: Company vows to reduce amount of chemicals that may cause cancer

Health authorities have launched a fresh inquiry into the safety of a caramel colouring used in soft drinks such as Coca-Cola and Pepsi.

The decision has been taken by the American Food and Drug Administration (FDA) in response to research showing varying levels of 4-methylimidazole (4-MI) in 12 brands of soft drink.

The agency said it is also reviewing new data on the safety of 4-MI in other products.

In the past the FDA, as well as food watchdogs in Britain and Europe, ruled that the chemical poses no threat to the health of consumers.

However, health authorities in California include the substance on a list of cancer-causing agents.

As a result drinks companies are required to put a cancer warning on products containing raised levels of 4-MI.

In response to the law, Coke, Pepsi and other manufacturers directed their caramel-colour suppliers to reduce the levels of 4-MI.

Coca-Cola subsequently promised to reduce levels of 4-MI in drinks sold around the world. 

However, the same safeguard  was not applied by Pepsi in a decision which outraged food campaigners in the UK.

American campaigning group Consumer Reports tested Sprite, Diet Coke, Coca-Cola, Coke Zero, Dr Pepper, Dr Snap, Brisk Iced Tea, A&W Root Beer, Pepsi, Diet Pepsi, Pepsi One and Malta Goya.

The tests found that single servings of two products purchased in California – Pepsi One and Malta Goya – exceeded the level of 4-MI which should have required a cancer warning on the label. No significant level was found in Sprite, and consistently low levels were found in Coke products.

Toxicologist Dr Urvashi Rangan, who led the Consumer Reports investigation in the US, said:  ‘There is no reason why consumers need to be exposed to this avoid-able and unnecessary risk that can stem from colouring food and beverages brown.’ 

However, PepsiCo has challenged the accuracy of the test results. 

Aurora Gonzalez, a spokesman for the firm, said the company was ‘extremely concerned’ about the reliability of the study.

She said: ‘PepsiCo abides by the law everywhere we do business.’ 

The UK arm of the drinks business has rejected claims that 4-MI poses any risk. 

Last year, the company said: ‘There is no scientific evidence that 4-MI in foods and beverages is a threat to human health.

‘Current regulation in the EU states that caramel colouring (4-MI) poses no health risks.’