How Food Allergens Contaminate Your Food

Food allergens can be sneaky, entering the food supply in surprising ways. It’s not enough to keep a vigilant eye on your food allergens. And, it’s not enough to avoid them. You have to know how, why, and where potential food allergens creep into the foods you eat.

Here are 6 sneaky ways food allergens get into your food:


Utensils can contaminate food. Image Source/Getty Images

Imagine this scenario: You are at the ice cream shop and you order vanilla ice cream, taking care to avoid tree nuts because you are allergic to them. The server grabs the ice cream scoop from the pralines and cream ice cream bucket and uses it to scoop out the vanilla ice cream. Because the server used the same scooper for both ice creams, the vanilla ice cream is now contaminated with tree nuts (pralines—a candied pecan). This situation can happen at a salad bar, at home when one utensil, such as a spoon, is used for multiple dishes, or in a restaurant if staff are inadequately trained to accommodate food allergies. Research suggests that close to half of all fatal food allergy reactions are attributed to eating outside of the home.  

Food Processing

Food processing
Allergen contaminates can get into food during processing. andresr/Getty Images

A variety of different foods are processed by both large and small food manufacturers. Think of large companies who have several different brands and food lines—how do they do it?  Do they use separate conveyor belts for each food? No! Conveyor belts must be wiped down thoroughly between food production lines to ensure allergens are eradicated prior to processing another food. If they aren’t, cross-contamination can occur. Remember, although many manufacturers include potential contamination notices on their food packages, they are not required to do so--it is a voluntary notification. 

Misleading Ingredient Labels

ingredients labels
Some ingredients labels can be misleading.

Some food labels can be unclear.  For example, they may include ingredients that are listed according to their function, such as an emulsifier, instead of noted by their ingredient (an emulsifier containing egg). Or, an ingredient may be listed as a whole food, such as mayonnaise, rather than by the ingredients it contains, egg, oil, vinegar and salt, listed individually. This can cause confusion and may lead to purchasing a product that may not be safe for you or your child.

Trace Ingredients

nutrition facts panel
Not all ingredients are included on the label. Jason Antony, stock.xchng

Often, very small ingredient amounts aren’t listed on the label but they are still there. The eight most prominent food allergens will be included on the label by law, but other, less common food allergens in trace amounts may not be listed. This can be problematic for individuals with food intolerance or food sensitivities

Ingredient Substitutions

Manufacturers may use a substitute ingredient if they run out of ingredients. Nico Tondini/Photographer's Choice/Getty Images

Occasionally, a food manufacturer may run out of an ingredient and decide to make a substitution. For example, one type of oil may be substituted for another type of oil, such as canola oil for a shortage of safflower oil. What makes this scenario difficult is the obvious change in the product ingredients and the potential for not updating the ingredient listing. 

Kitchen Preparation

Kitchen prep areas must be thoroughly cleaned.

Crumbs in the toaster, unclean pans, or sharing a butter knife are all ways allergen-free food can become contaminated with food allergens. When you have someone in the house with food allergies, care must be taken to wash dishes and utensils thoroughly, wipe and disinfect countertops and clean kitchen machinery. A 2004 study in the Journal of Allergy and Clinical Immunology showed that peanut residue was easily cleaned from counter-top surfaces with common household spray cleaners and sanitizing wipes but not with dishwashing liquid alone. 

Better Safe than Sorry

Watching out for food allergen contaminants is an ongoing job. Keep these six sneaky ways your food could be contaminated with food allergens in mind and you'll be safe, not sorry.

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