Ask Shelley Case: How to Avoid Cross-Contamination

Question: I prepare most of my own gluten-free meals but think I am still somehow ingesting gluten. Could it be cross-contamination while preparing and cooking meals at home? I think I’m careful, but could you give me some pointers on how to avoid potential cross-contamination in my own kitchen?

Answer: In addition to always checking the ingredients in any food you eat, you must also be aware of the possibility of cross-contamination (a process by which a gluten-free product comes into contact with something that is not gluten-free).

Many people, as careful as they are, unwillingly still ingest gluten by cross-contamination, even in their own homes. Here are some pointers and guidelines to help you prevent this avoidable ingestion of gluten:

• Label It: Store all gluten-free products in separate labeled containers. Some families buy bright stickers and put them on everything that is and/or should remain gluten-free. In addition, you may want to keep all gluten-free foods in a separate place in the cupboard and refrigerator. Another tip is to store gluten-free products on the upper shelves of the pantry or cupboards ABOVE the gluten-containing products to prevent flour dust and crumbs from falling onto the packages and containers of gluten-free items.

• No Sharing Allowed: Buy separate containers of items like peanut butter or jam and label “gluten-free” to prevent them from becoming cross-contaminated by other family members preparing gluten-containing products (e.g. toast, sandwiches).

• Give it a Squeeze:  Buy squeeze bottles of condiments such as ketchup, mustard, relish and mayonnaise. This prevents any crumbs from getting in the containers.

• No Double Dipping: Avoid other’s crumbs! Have a separate butter or margarine container designated for gluten-free users only.

• Even a Little Gluten and You’re Toast: Have your own toaster. If not, use a toaster oven, where the rack can be removed and washed if others have used it. Another option is to buy special toaster bags for gluten-free bread that can be placed in a regular toaster. These bags can be washed and re-used. Available from,, or

• Space it Out: Always make sure that the counter space you are using to prepare gluten-free foods is freshly washed to ensure it is free from crumbs or flour dust.

• Scrub, Scrub, Scrub: Make sure pots, utensils, etc., that are also used for other foods are thoroughly scrubbed before using with gluten-free foods.

• Pasta Concerns: Do not boil gluten-free pasta in the same water that previously had gluten-containing pasta. Also use a separate colander to drain gluten-free pasta, as it is difficult to remove traces of pasta from the colander.

•You-Tensils: Have your own set of utensils and other items for gluten-free baking and cooking (e.g., wooden spoons, cutting boards, sifter.)


Ask Shelley Case is a feature of It is published the second Tuesday of each month. Shelley Case is a Registered Dietitian, Consulting Dietitian, Speaker and Author of Gluten-Free Diet: A Comprehensive Resource Guide. Visit Shelley and get more gluten-free tips & info at:

Tags: ,

9 Responses to “Ask Shelley Case: How to Avoid Cross-Contamination”

  1. Darlene Rhoads Says:

    I am a celiac we also have chicken’s their scratch grain has wheat,barley,rye in it does this pass into the egg’s?
    When I breathe the dust from the chicken feed cause gluten to get into my system?
    I handle their food with bare hand’s can the gluten go through my skin?
    I have been using medical gloves to feed them should I keep using these gloves?
    Darlene Rhoads

  2. Heather Says:

    We use the squeeze bottle idea but one thing we learned to be careful of is contaminating the outside of the bottles. It seems to happen frequently, especially when there are groups of people using it (especially like picnics, backyard BBQ’s ect). The bottle gets wet/greasy what ever and then gluten crumbs gets stuck to it. The a GF person uses the bottle and before you know it there own food is contaminated and you have a sick miserable person. At least thats been my experience as a very sensitive celiac.

  3. Rebecca Stocking Says:

    I’d like to add a few:
    Remember to also wash the microwave after ANY gluten is heated in it – or buy microwave-safe food covers.
    Keep in mind that if you have an automatic dishwasher, the dishes come out sanitized, so you only need to have duplicates of porous dishes and utensils. Stainless steel and glass will not retain gluten.
    Also, if you wash things by hand, be careful that you aren’t washing the gluten dishes, and that the sink is clean when you begin washing dishes. Wear gloves!
    If you can afford it, invest in an air-cleaner for your kitchen. It will pull flour dust particles out of the air and into it’s filter.
    It is so much easier and great for my peace-of-mind to have a gluten free kitchen where I know that I will not have ANY cross-contamination. If you are a head-of-household, you should discuss this with your family. My family has agreed to eat gluten free at home.

  4. Joe Says:

    I think that the public needs to be better educated on this issue. I have been to so many parties where there will be food labeled “gluten free” and one of two things will happen:
    1. Somebody takes a utensil from a glutenous food and uses it in the gluten-free food.
    2. Somebody serves the gluten-free food on the same plate as glutenous food.

    This is rather frustrating to me! On top of that, the FDA needs to add “gluten” to their list of known allergens. Simply adding the words “Contains wheat” or “Prepared on the same equipment as wheat products) is not enough. I was diagnosed with gluten intolerance about a year ago. I just recently learned that malt contains gluten. There is a whole freaking list of items that “may” contain gluten. Nothing seems to be concrete. Yet we are warned that gluten can do so many bad things to your body if you are sensitive to it. I am so sensitive to gluten, that there have been times when I have been sick for a couple of days at a time and I do absolutely EVERYTHING in my power to keep that crap out of my system. I have learned that in China, some places coat wheat on their food to keep it from sticking together in the package. This is not even listed in the ingredient list. Doesn’t this frustrate anybody else here?

  5. Barb Says:

    Like Rebecca, I have a gluten free kitchen. My husband eats what I eat. He has regular cereal and keeps it in a different cupboard than mine. I have part of a large utility cupboard where I keep gluten free products. When our daughter comes home to visit, I buy regular bread for her and wash down the counter when she is done using it. I also bought some new cutting boards and marked the old ones with an x to be used for gluten bread. I think it would be stressful to have to balance two diets in my kitchen. I have a separate toaster for gluten free, a new stainless steel colander, and have thrown out my wooden spoons. I bought a bread machine with a gluten free setting and replaced some old small appliances with new ones. I bought new cookie sheets, bread pans, and cake pans since the old ones had some scratches on them and I was concerned about gluten hiding in the scratches.

  6. Sam Says:

    I’m wondering about the oven. I’ve had reactions a couple of times when something has been baked in the oven. It wasn’t baked WITH gluten products in there, but gluten has been baked in there. Is it possible that caused the reaction?

  7. Shelley Case, RD Says:

    Although poultry, pork and beef can be fed gluten-containing grains, individuals can consumer these foods as the toxic 33 mer gluten peptide that triggers the celiac reaction is not in the meat . So enjoy beef, pork, poultry and fish.

    Regarding inhaled gluten:
    There was a case report in the New England Journal of Medicine (356;24 june 14, 2007) about non responsive celiac disease because of inhaled gluten. Two farmers with celiac disease following a strict gluten-free diet who fed cattle with a wheat and barley containing feed continued to have elevated celiac antibody levels and villous atrophy. Wearing a mask resulted in resolution of symptoms, decreased antibody levels and healed villi in one farmer and the other farmer had a resolution of symptoms. The physicians concluded that individuals with a farming background with celiac disease should wear a mask and limit exposure to feeding animals to reduce exposure to inhaled gluten. This can “markedly reduce symptoms and improve histological abnormalities.” So it is possible that inhaled gluten can make someone sick especially with repeated exposure.

    The issue of cross contact of gluten and skin has been debated for sometime. D. John Zone, dermatologist and celiac expert as well as Dr. Alessio Fasano states that gluten must be ingested through the mouth to cause a celiac reaction. Cross contact with gluten on the skin is not a concern. Here is a link that discusses this further:

  8. Cali Says:

    What about spices?

    I’ve had great difficulty in finding gluten free spices. Although Mccormicks is fairly good, and actually uses strictly ‘spice’ lines, they don’t have everything. I called President’s choice the other day, to ask how their food processing takes place for spices and they process spices on the same line that gluten containing products are processed on. But they claimed that with strict sanitizing procedures that the spices do not in fact have gluten in them. How trust worthy is that type of situation? Anybody just use spices without even thinking about it? I’m looking for gluten free sesame seeds, and coming up short.

    Thanks for any info anyone wants to throw my way.

  9. Kathleen Reale Says:

    Wow! These are all great comments! Shelley thanks so much for your reply too. We all appreciate you posting answers to the additional questions.

    This reminds me to have everyone sign up for Shelley’s webinars on 06/15 & 06/22. Shelley will answer tons of questions like this. These webinars are informative and fun… so make sure you attend! You can find more info and register to attend here:

    Cali- You can find information on spices and seasonings on a blog post Shelley wrote for BeFreeForMe a few months back – here is the link:
    I’ve had good luck with the McCormick spices, but does anyone else out there use any others with luck? If so, please let us know!

    Thanks everyone for the community and support with helping each other out. I love all the additional ideas and thoughts on this blog post!

    Be Free!

Leave a Reply

Be Free For Me Blog is proudly powered by WordPress
Entries (RSS) and Comments (RSS).