Cross contact is an important risk to be aware of when you have food allergies or Celiac disease. In this guide, we’ll dive into what cross-contact is, where it can happen, and how to prevent it so you stay healthy and safe.
What is Cross-Contact?
I see the terms cross-contamination and cross-contact used interchangeably a lot. While they both generally mean the same thing, there is an important distinction between the two.
First, let’s talk about cross-contamination. This happens when you transfer bacteria from one food to another. It can happen at any time during food production and can cause food-borne illness (aka food poisoning).
To prevent this, you must keep foods that are raw or not washed away from prepared, ready-to-eat foods.
For example, if you put a piece of raw meat on a cutting board and then use the same cutting board to chop up raw veggies for your salad, you have introduced potentially harmful bacteria to your salad. This is cross-contamination.
Now, when you cook that meat to a certain temperature the bacteria would be killed and it would be safe to eat.
So, what is cross-contact? This happens when foods come into contact with each other and their proteins mix. When this happens, each food contains a little bit of protein from the other.
Even the tiniest amount of a food allergen can cause a reaction. Cooking the food doesn't remove the allergen.
This is the key difference between cross-contamination and cross-contact.
In the food allergy world, we use the term cross-contact when referring to allergens because, again, cooking foods with allergens does not remove the allergens.
When you have food allergies, it doesn’t really matter what you call it as long as whoever is preparing the food understands that important point.
Tips for preventing cross-contact while preparing food
Wash all utensils with soap and water before and after handling food allergen(s). This includes pots, pans, knives, stirring spoons, cutting boards, etc. Many people may think it is good enough to just "wipe off" utensils. Unfortunately, this is a very common mistake. If you're trying to explain it to someone and they're not getting it, use the raw meat analogy.
Wash all surfaces where foods containing food allergen(s) were prepared with soap and water. This one goes right along with the utensils. Again, treat the allergen(s) the way you would raw foods to avoid cross-contamination.
Wash hands often. You really can't go wrong with good handwashing habits!
Be mindful of shared containers
Shared containers of food are one example of where cross-contact happens at home. This is especially challenging for people avoiding gluten/wheat.
Think about how you normally would make a peanut butter (or sunflower butter) and jelly sandwich. You get out your bread, then you take your knife to the jar of peanut butter, spread it on the bread, and then dip the knife into the jelly jar, then spread it on the sandwich.
Oops....that jelly is now the victim of cross-contact which puts you at risk if you're following a strict wheat/gluten free diet.
If you’re a family that has one person who is allergic to a food but the rest of you eat it, you will want to have strategies in place to avoid this.
One thing I do is only use spoons in jars instead of knives. Yes, you can use a spoon to spread things on bread but using a spoon is a reminder to me that I’m taking what I need and not dipping it back into the jar. If I must get more, I need to get another spoon.
Another shared container that might be contaminated with wheat is sugar containers when baking with wheat flour.
Many people measure out flour first and then use the same measuring cups to measure out sugar. This introduces wheat into the sugar and anything you bake with it (using gluten free flour or not) will potentially contain wheat.
These are just a few examples of cross-contact in shared containers. Take some time to think about your allergens and kitchen processes where cross-contact might occur. Then create systems to prevent it.
Cross-contact when dining out
Dining out is one of the most challenging parts of eating with food allergies because we don’t have control over what is going on in the kitchen.
My son who is allergic to wheat, barley, dairy, eggs, and peanuts loves a certain Mexican restaurant where almost everything is safe for him. The only thing he can’t have there are flour tortillas, cheese, and sour cream. It’s a place where he can get a healthy, well-balanced meal and he really enjoys it!
But just because most of the ingredients are safe doesn’t mean he can always get a safe meal there. As workers put together each order, shredded cheese creeps into other containers making those safe ingredients unsafe.
So what can you do?
Communicate clearly about your allergens. This can be hard but the more you do it, the easier it will be. Many restaurant staff members really care and want to make sure you have a safe meal.
Ask workers if they can change their gloves. Don't worry if it feels high maintenance. Your safety is important and you're worth the trouble!
Ask if there are certain ingredients available from a fresh container that hasn’t been contaminated. Sometimes restaurants will have portioned out ingredients for takeout orders or for people with food allergies. You’ll never know if you don’t ask! And asking might help plant the seed that doing that would be helpful for future diners with allergies.
Go to the dining out with food allergies post for more tips.
Cross-contact during gatherings
Whether it’s a family gathering, a company party, or gathering with friends there is one thing that is almost certain: there will be food!
Now, there are lots of things to consider when it comes to gatherings. We’ll just focus on preventing cross-contact during a buffet-style meal.
In this type of meal, each person goes through the line and dishes up their own food. The risk of cross-contact can be high, even when being very aware.
For example, when serving some type of meat on a bun such as pulled pork or a sloppy joe, it is very difficult not to touch the bun with the tongs or spoon. That utensil then goes back into the meat causing cross-contact.
You can do some things to reduce the risk whether you’re hosting or attending a buffet-style gathering:
- Allow those with food allergies to dish up first. When we get together with my family, my kids always go through the line first. We encourage them to take a generous portion so they don’t have to go back through the line after everyone else has dished up.
- Set aside some of the dishes that might come into contact with allergens (such as meat that will go on a bun). Keep that separate from other foods.
- Set up the serving area to keep “safe” foods separate from foods that contain allergens. For example, if someone has a shellfish allergy, move the shrimp cocktail to a separate table or area on the buffet line. If you are having tacos and someone has a dairy allergy, move the cheese and sour cream to a separate area.
- Have separate utensils for everything!
- Teach little ones to use utensils or ask for help in dishing up rather than using their fingers.
Even with all of the strategies in place, cross-contact happens. The important thing is that you don’t take the risk of eating the food that has come into contact with your allergen(s).
For this reason, try to have a backup plan. Pack a meal in case there isn’t safe food available. This isn’t ideal but it’s better than watching everyone else eat while you’re starving!
For more about label reading and cross-contact, visit the common food allergies page.