25 Ways Cross-Contact Could Happen (And How to Avoid It)

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Cross-contact is a concern when you’re living gluten-free, especially if you have been diagnosed with celiac disease or non-celiac gluten sensitivity. 

What exactly is cross-contact?

Cross-contact is when gluten crumbs or particles get into gluten-free ingredients or food in amounts that could cause an adverse reaction. This risk can occur at any stage of food production, including farm fields, food storage areas, and shipping containers before ingredients even get to manufacturers. 

Cross-contact can happen when you live in a mixed household of both gluten-free and gluten eaters or when you’re eating away from home and have less control over the food preparation. Here are 25 ways cross-contact might occur and how to avoid it. 

At Home/Home Life 

  1. Wash All Surfaces and Utensils. Thorough cleaning of cooking equipment and utensils with soap and water is sufficient for most items. For more information, read our article 7 Tips for Avoiding Gluten Cross-Contact at Home.
  1. Get Two of Each (as Needed).  Items like colanders, sifters, and waffle irons are more difficult to clean thoroughly. These should not be shared between gluten-free and non-gluten-free use, if possible. If not, it is important to clean the item thoroughly between every use.
  1. Keep it Separate. If you’re not living in a fully-gluten-free home, keep designated areas in your kitchen for gluten-free food storage and prep. Wipe down any food prep or cooking surface often and always after preparing or making dishes with gluten-containing ingredients.
  1. Rearrange It. Flour or baking mixes could make dust. Crackers and cookies could generate crumbs. If you store both gluten-free and gluten-containing food in the same fridge or cupboard, put the gluten-free packages above the gluten-containing ones and keep them securely packaged.
  1. Label It. When in doubt, create labels for food items in your kitchen, even utensils and cookware. Designate what is gluten-free or to be used for gluten-free food prep, cooking, baking, and storage.
  1. Go Totally Gluten-Free (optional). While this option is not for every household, some families choose to go entirely gluten-free. Note that this may not always be healthy for all family members who do not have celiac disease, NCGS, or other conditions that might require a gluten-free diet. Gluten-free diets can lack nutrients. 
  1. Don’t Double-Dip. One of the most common ways gluten crumbs can get into gluten-free food is through “double-dipping” or the use of the same serving utensil in both types of food. A knife in a condiment jar—like mayonnaise—used to spread mayo onto wheat bread then dipping the same knife back into the mayo to spread it on gluten-free bread is a cross-contact warning!
  1. Keep Topicals Out of Your Mouth. We know you wouldn’t eat a product for external use only on purpose. To date, medical research does not show that the topical application of gluten to the skin causes a reaction related to celiac disease. That goes for topicals such as lotions, sunscreen, and bug spray. The main concern is when a topical gets into the mouth and is ingested. For more information about skin care products, read our article “Gluten-Free Skin Care.”
  1. Double-Check Dietary Supplements and Medications Dietary supplements that are labeled gluten-free are covered by the FDA gluten-free labeling regulation and should be safe. You can also find GFCO certified gluten-free supplements here: https://gfco.org/product-directory/.  Gluten-free labeling regulations do not apply to over the counter or prescription medications. While most prescription medications are gluten-free, confirm that any excipients (inactive ingredients) they contain are gluten-free. Double-check medications and dietary supplements. Ask your pharmacist to confirm gluten-free status, and/or check with the manufacturer yourself. Check out our article “Are Your Medications and Supplements Gluten-Free?” for more information. 

Food and Drink

  1. Oats. Individuals with celiac disease should only consume oats that are certified, or at the least labeled, gluten-free and generally only in small amounts. Individuals with celiac disease should consult with their physician or dietitian before introducing oats into their diet. For more details, read: Are Oats and Oat Flour Gluten-Free?
  1. Milk and Cheese. Most milk and cheese products found at the grocery store are safe to consume, even if they are not labeled gluten-free. Just as with any non-labeled or non-certified product, read the ingredient list carefully to confirm there are no gluten-containing ingredients added as flavorings. Cultured dairy products could, in some cases, contain small amounts of gluten since cultures can be grown on gluten-containing grains.
  1. Spices. To be safest, choose spices that are labeled gluten-free in accordance with FDA regulations, or for additional assurance, that are GFCO-certified as gluten-free. As is the case with all food products, gluten-free labeling is voluntary. Read more about spices and their gluten-free status.
  1. Alcoholic Beverages. Distilled spirits and wine are usually gluten-free. Learn more about wine in our article Is Wine Gluten-Free? and more about spirits in our article Fermentation Versus Distillation.


Away from Home/Social Life

  1. Look for GFCO’s Certification Mark. When grocery shopping, choosing packaged foods labeled “gluten-free” should mean that you’re purchasing food under the FDA’s standards of less than 20ppm of gluten, however, there is no guarantee those foods are being properly tested for their gluten content. For added assurance, purchasing GFCO-certified food means it meets the threshold of 10ppm of gluten or less.
  1. Read Labels. When food shopping, label reading can reveal gluten-containing ingredients in prepared foods. Learn what you should be looking for in our article 3 Tips for Gluten-Free Label Reading.
  1. Watch the Bulk Bins. Stay clear of the store’s bulk section where gluten-containing ingredients could linger on scoops or surrounding bins, leading to unavoidable cross-contact. Even if the scoop is in the bin of a gluten-free food, it could contain gluten particles from a previous bin or from exposure to a gluten-containing food elsewhere in the bulk bin area.
  1. Ask Questions. Eating out? Check out the questions you should be asking wait staff, the manager, or the cook or chef about how they handle their gluten-free food. Restaurant Dining: 7 Tips for Staying Gluten-Free.
  1. Look for a GFFS Gluten Free Safe Spot. A GFFS-validated Gluten Free Safe Spot is a food service establishment where staff are trained in safely preparing gluten-free food.
  1. Ask for the Gluten-Free Menu. More restaurants are paying attention to the gluten-free needs of their customers and produce a separate menu with gluten-free dishes or modified dishes made to be gluten-free. While this effort is helpful, not all places know how to prepare gluten-free foods safely. When there isn’t a separate gluten-free menu to peruse, ask wait staff—or the manager or chef—for gluten-free options. Even when there is a gluten-free menu, it’s important to ask questions since staff are not necessarily aware of the details involved in preparing safe gluten-free food.
  1. Watch the Salad Bar. Any buffet-style display of food introduces new opportunities for cross-contact. A salad bar typically has a combination of naturally gluten-free food like vegetables and fruit alongside gluten-containing food like croutons, crackers, and even some salad dressings. Even if kept apart, the serving utensils might inadvertently be used in both. Salad bars are best avoided (unless at a food service establishment validated as safely gluten-free).
  1. Ask to See the Package. When eating out and in doubt about the ingredients in a prepared dish—or the wait staff are unsure of the ingredients—ask to see the package of any questionable ingredients that went into preparing the food. Most eating establishments can accommodate this request.
  1. Speak Up. If you are eating at the home of someone who is unfamiliar with your requirement for gluten-free food, communicate about your dietary needs in advance. You may not always feel comfortable doing this, but you will be able to enjoy the meal with more confidence when you advocate for yourself.
  1. Educate the Host. If you believe the host would be receptive—and especially if it is someone you expect to interact with in the future—graciously inform them of your gluten-free needs, and the importance of avoiding cross-contact of gluten-free foods they may be offering with any that do contain gluten.
  1. Bring Your Own. If attending an event and you do not know the host very well, you may wish to bring your own gluten-free food. Traveling by train or plane? While planes are typically good at accommodating dietary restrictions, trains are not. Even when on a road trip, bringing your own snacks is a great way to have a backup of something to eat if you need it. See Gluten-Free Eating on the Go and Gluten-Free on Planes, Trains, and Automobiles.
  1. Be Prepared. The best way to stay safely gluten-free is to be informed, ask questions, and know ahead of time where cross-contact might happen so you can avoid it or be prepared for it. Being prepared—and choosing GFCO-certified products—helps bring peace of mind to your eating experience so you can enjoy what you eat!


The information on this website is for educational purposes only. Consult your healthcare team when considering this information.

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