MONDAY, Aug. 7 (HealthDay News) -- Food packaging that contains latex should be labeled in order to prevent latex-sensitive people from being exposed to potentially deadly levels of the allergen, a group of experts said in response to a recent study.

The U.K. study found that a third of food packaging tested was contaminated with latex and that, in some cases, the latex was transferred to the food. One brand of chocolate biscuit contained 20 times the amount of latex that can cause a reaction. It's believed that as little as a billionth of a gram (1 ng/ml) can be enough to cause a reaction.

Researchers measured the presence of four major latex allergens in 21 types of food packaging for fruits and vegetables, meat, confectionary, pastry and dairy products. The highest latex levels were on ice-cream wrappers. One ice-cream wrapper had more than 370 ng/ml of latex, and the ice cream itself contained about 14 ng/ml.

One company told researchers that it sprayed entire wrappers with latex adhesive, so that the wrappers could be sealed with minimum wastage.

The study was published in the Journal of the Science of Food and Agriculture.

The findings are significant, experts from the U.K. Latex Allergy Support Group (LASG) Advisory Panel told the journal Chemistry & Industry.

"For a few people, natural rubber latex is a very potent allergen, and for these individuals, there is no safe level of exposure," LASG representative Graham Lowe said in a prepared statement. Latex transfer to food could account for some currently unexplained reactions, he noted.

SOURCE: Chemistry & Industry, news release, Aug. 6, 2006