HealthDay News — Food labels may not accurately list all possible food allergens, reported the Food and Drug Administration in a consumer update. These undeclared allergens are the leading cause of FDA-requested food recalls, added the agency.

Roughly one-third of all foods reported as serious health risks involved allergens that were not included on food labels. Most often, the foods involved were bakery products, snack foods, candy, dairy products, and dressings or sauces. The allergens most involved in frequent recalls were milk, wheat, and soy, reported the FDA.

Labeling errors most often occur due to use of the wrong label; this happens when similar products are sold in similar packages but contain different ingredients, including allergens.

To prevent FDA recalls, the agency said is it investigating why some possible allergens are omitted from food labels. The agency also reported it is working with the food industry to improve testing for the presence of possible allergens.

“The data suggest that food allergen recalls can be reduced through improved industry awareness and simple changes in the way packages, labels and ingredients are handled and tracked within production facilities,” said the FDA.