Salt sounds like such a pure product, but actually *most* brands available for sale in the grocery store cause issues for those with corn allergies, even those of medium sensitivity. The below statements apply to sea salt and table salt both:
- Packaging: Cardboard, especially recycled cardboard can contain corn fibers and may be dusted with corn starch to prevent it sticking together. Plastic may contain polymers from corn starch or may be dusted or oiled with corn products to prevent sticking.
- Ingredients: Iodized salt contains dextrose from corn to help the iodine stick to the salt crystals. Non-iodized salt often contains an anti-caking agent, which may not be directly from corn but often causes more sensitive corn allergics to react, probably due to cross contamination.
- Cross contamination: Companies that mine/extract/synthesize and package salt often produce a number of different products. Cargill is one example. Many of those products contain corny ingredients, and cross contamination is possible in the facilities.
The most sensitive folks with corn allergies actually have a very, very hard time with salt. In fact there is NO salt product out there that SOME corn allergic person hasn’t reacted to. Not one. You just have to pick some best bets based on who has reacted and how much their particular sensitivity matches yours, as people react differently to different derivatives.
What works for many people who cannot tolerate any pre-ground salt is to get a slab of himalayan salt intended for cooking, or large chunks of himalyan salt and rinse the outside under safe water for long enough to remove a layer from the exterior (presumably washing any contaminants down the drain with that layer), and then let it dry again and use a large blunt implement to whack the salt down into coarse chunks which you can load into a grinder. I use a large mortar and pestle designed for guacamole for this. DO NOT STICK LARGE ROCKS OF SALT INTO YOUR BLENDER, not even if you have a Vitamix or Blendtec. These are essentially rocks and will bust a hole through the side of your blender jar. If you get the rocks down to gravel sized that should be fine for the blender however.
Another technique I’ve been using lately is to use the chunks, rinse the outside, and then stick them in a jar full of water and shake it around to make a strong salt solution. This is much easier, but can be a bit difficult to measure how much salt to use. Full credit to Marci for this particular innovation.
Corn Allergy Girl 
I knew it! With all my combined food allergies, potato chips used to be the one thing I could safely eat. For quite some time I have had reactions to eating chips and thought they were sneaking corn oil in even if the label said otherwise. The only thing left is salt. How can companies get away with not disclosing this? It is an ingredient. We’ve come so far with labelling but still a ways to go..
Hi Beth! In addition to the salt, the oil the chips were fried in could also be an issue. A number of oils such as canola and sunflower need a degummer during the pressing process, and citric acid is commonly used for that. Additionally, there could be cross contamination in the facilities, such as if the same factory processes potato chips flavored with maltodextrin.
Kettle used to work but about a year ago something changed and everyone started reacting. 😦
You might like to check with the folks on the Facebook corn allergy group or the Delphi Avoiding Corn forums to see if they are using any chips successfully. I am so sensitive to tiny traces of cross contamination these days that I avoid all prepackaged/precooked items. So I can’t give you a product suggestion, but they might have ideas.
As for labeling, indeed there is a long way to go. It would help immensely if corn was considered a top 8 allergen by the FDA. If that were the case, manufacturers would be required to print warnings such as “may contain corn,” on products that were produced in the same facilities or that have ingredients that were derived from corn. But even then, people do not always comply with these rules. Heck, sometimes they don’t even list all the ingredients on their label, period! Sometimes they are breaking the law by doing so, and sometimes they are taking advantage of loopholes in labeling laws. It’s all very frustrating, and when you reach a certain level of sensitivity unfortunately your best choice is to just avoid things you didn’t make yourself. Depressing, I know.
I am currently having good results from HimalaSalt brand himalayan sea salt. In the chips department, I have best luck with Boulder Canyon Sea Salt flavor although I do wipe off most of the salt along with some oil (all chips taste better this way!)
What about Kosher salt? Same everything applies? I’m very new to avoiding corn although I’m very experienced at avoiding gluten/dairy/egg. It seems like some kosher things are strictly corn free and some less so?
To answer your salt question- kosher salt usually is just salt, but may contain anti-caking agents and iodine and dextrose. You’d need to check the ingredients label. Nothing about the rules of kosher (vs kosher for passover) would make the addition of those ingredients not kosher.
To explain why you see some kosher items that contain obvious corn and some that do not, that’s because kosher and kosher for passover are two different things. “Kosher” is food that conforms to the rules of kashrut. Kosher food can contain corn.
https://www.myjewishlearning.com/article/kosher-food/
Kosher for passover is kosher food that follows additional rules specific to that holiday. Specifically chametz (leavening) is avoided, and in some traditions, kitniyot (legumes and several kinds of grains including corn) is avoided too.
https://www.myjewishlearning.com/article/passover-foods-and-the-passover-kitchen/
This religious tradition has been very helpful to people who are “corn lite” meaning they need to avoid direct corn ingredients. But it isn’t foolproof- not all traditions agree on what is included in kitniyot (such as derivatives) or even whether kitniyot needs to be avoided. In the end the kosher for passover label can be one more helpful guide to something that could be safe, but since it is a label intended for religious observance, it isn’t necessarily going to cover our needs.