Tests funded by the Food Standards Agency on 21 types of packaging have shown that a third were contaminated with latex, which in some cases was transferred to the food.

The findings have prompted calls for new labelling rules to ensure that consumers are aware of the use of latex in packaging across Europe.

In one chocolate biscuit the amount of latex found was almost 20 times the level that can trigger a reaction in a person sensitive to latex rubber.

Contamination by rubber proteins was also discovered in ice-lollies and pastry, in stickers used on fresh produce such as avocados and apples, on rubber bands used to tie spring onions and asparagus and in the netting that keeps joints of meat intact.

Natural latex, derived from the sap of rubber trees, is commonly found in the adhesive used to cold-seal ice-cream, chocolate bars and biscuits and other chilled foods where heat exposure would cause the product to deteriorate.

It can contain rubber proteins known to be harmful or even dangerous to sensitive individuals. Four of these proteins, known as “Hev” allergens, are recognised as being a health risk.

At present manufacturers are not required to include latex warnings on packaging labels.

There is no agreement on what constitutes a safe level, but as little as a billionth of a gram (1 ng/ml) has been known to trigger an allergic response.

The research, which is published today in Chemistry & Industry, the magazine for the Society of Chemical Industry, was conducted by Leatherhead Food International, a leading science research laboratory, on behalf of the Food Standards Agency. It is the first known study to quantify the presence of latex in food and packaging.

The agency said that it was too early to draw firm conclusions. It advised people not to alter their eating habits or the way they prepare food.

Joanna Topping, a food technologist who led the research, said that the survey of 21 food products found that one third of the packaging contained latex. Highest levels were found in ice-cream wrappers, including one choc-ice wrapper containing 374 ng/ml of latex protein.

Another possible route for contamination is the widespread use of latex gloves by workers in the food industry.

Graham Lowe, a consultant dermatologist in Dundee, called for the use of latex to be listed on food labels. He said that the use of latex gloves should be reduced in production, adding that they were largely unnecessary.

ALLERGIC REACTION

• Latex intolerance affects between 1 and 6 per cent of the population. Extremely sensitive individuals exposed to the allergens could suffer a fatal anaphylactic reaction
• Typical reactions for a mild latex allergy sufferer include itching, redness or swelling, but it can also affect eyes and breathing and in the most sensitive individuals can trigger heart attacks
• People tend to learn of their allergy when they try to blow up a balloon or wear kitchen rubber gloves
• In the UK there are known to be at least 350 people who suffer serious problems and who are now members of the UK Latex Allergy Support Group

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