As a parent of a toddler and a dietitian, I have spent many hours reading about foods that may cause an allergic reaction and how to find potential allergens on food labels. You may have noticed wording on some labels that state "may contain" peanuts, shellfish, or other ingredients known to cause allergies in some people. But it's not always this clear what's safe for your child to eat if he or she has a food allergy.

Did you know that according to the Food and Drug Administration, food allergies affect between 2 and 8 percent of children and 2 percent of adults? Though the percentages seem small, the risk of food allergy is important because these allergies can be lethal. If you shop for a person of any age who suffers from these allergies, it's imperative to read labels every time you go to the store. Remember, manufacturers frequently change product lines and ingredients, which means that you may have to take a previously "safe" food off your grocery list.

To help Americans more easily identify foods they may be allergic to, Congress passed the 2004 Food Allergen Labeling and Consumer Protection Act. Starting on January 1, 2006, packaged foods containing milk, eggs, fish, crustacean shellfish, peanuts, tree nuts, wheat, and soy must be labeled in plain language to identify that food on the ingredient list. The label must list even ingredients that are part of a coloring, flavoring, or spice blend. When nuts or seafood are used, the specific nut (such as tree nut) or seafood (such as lobster) must be listed.

You'll see allergens listed on food labels in one of these two ways:

1. The word "contains" immediately followed by the name of the food source from which the major food allergen is derived. The food source must be listed in at least the same size font as the ingredients, as in "contains soy."
   
   
2. The food source from which the allergen is derived immediately after the affected ingredient, as in "albumin (eggs)."

Many foods not covered by the new law also have been linked to food allergies, but research has shown that the eight foods covered by the Act cause 90 percent of food-related allergic reactions.

This law will help the estimated 12 million Americans who suffer from food allergies. Nevertheless, the Food Allergy and Anaphylaxis Network reminds us that packages that were manufactured before January 2006 may still be on store shelves for up to one year and, consequently, you should continue to carefully review all ingredient lists when you shop.