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Why We Need To Heed Food Label “May Contain” Warnings


Ongoing allergy education for the caregivers of food allergic kids is necessary, according to a recent Canadian study.

The researchers found a third of the 92 childhood anaphylaxis events they looked into occurred as adults supervised children who were eating. Further, 65 percent of those supervising were caregivers other than parents, and many of them disregarded the “may contain” warning on food labels.

The Labels Were Ignored

In 32 of the studied cases, where allergic reactions were associated with packaged food, ten of the supervising adults (31 percent) called the food labels “unclear.” The remaining adults (69 percent) admitted they had not paid any attention to the food label.

Dr. Moshe Ben-Shoshan, researcher, and a pediatric allergist at the McGill University Health Centre in Montreal, warns parents and caregivers against ignoring precautionary statements on packaged foods. “A common case is that a parent will tell me their child has a tree nut allergy, but can usually tolerate a bar that says “may contain,” so they continue feeding that to their child,” says Ben-Shoshan.

The best policy is to always avoid foods that “may contain” a child’s allergen. The “may contain” warning refers to the possibility of cross-contamination during product manufacture, and there could be enough allergen present to cause a reaction.

May Contain

“May contain” on a food label indicates the product might contain an allergen owed to different products being made on the same equipment. Although equipment is cleaned after processing an item, small amounts of an ingredient might remain and become part of the next manufactured food.

If, for instance, equipment is used to make cookies with peanuts, traces of peanut might survive the equipment’s cleaning, and subsequently become part of the crackers that are produced next. So, the cracker label might say, “may contain peanuts,” though whether the product actually does contain peanut is unknown. However, as the Canadian study shows, ignoring this warning sometimes leads to life-threatening food allergy emergencies.

Many companies use “may contain” statements on their packaging, though doing so is voluntary.


Manufacturers are required to state the presence of the eight major food allergens - and any ingredients containing the allergen proteins - on all food labels. They can do this by:

  • Making allergens part of the ingredient list, or?
  • Using a separate “Contains” statement, such as “Contains: milk, peanuts.” This statement is placed immediately after, or next to the ingredient list.

If there is no “Contains” statement on a label, adults must carefully read the entire ingredient list to determine whether a child’s allergen is present. This is something non-parent caregivers should be periodically reminded to do.

“We hope [our] study increases food allergy awareness,” says Ben-Shoshan. "Tell whomever you are leaving your child with to read labels carefully."

Sources: Mariam Matti / Allergic Living; FDA Consumer Updates
Photo credit: Donnie Ray Jones

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