Why Gluten Parts Per Million Numbers Matter

More information is better when it comes to trace gluten amounts

As it’s commonly used, the term "gluten-free" does not mean free of all gluten. Instead, it means that a particular product is free of almost all gluten. But almost may not be good enough for many of us.

Gluten-free grains on a stone surface with a gluten-free logo in the center
What do gluten parts per million numbers mean?. Janine Lamontagne / Getty Images

Unless precisely defined, the term "gluten-free" is misleading. I don’t care how much the term is thrown around by manufacturers and writers, most "gluten-free" products are not really gluten-free — they just contain far less gluten than other products in their categories. The problem faced by those of us who are sensitive to trace amounts of gluten is that products rarely are labeled to specify the precise range of gluten they contain. Even the U.S. Food and Drug Administration (FDA) authorizes gluten-free food labels for products still "containing less than 20 parts per million of gluten or 20 mg/kg," proving some grain protein remains in "gluten-free" items.

Trace Gluten Reactions Vary a Lot

The amount of gluten in a "gluten-free" product can make a huge difference in how we react, just as the amount of alcohol in a drink can determine how we react to the drink. For example, we all know that drinking a jigger of rum that is 40% alcohol will cause a greater alcohol reaction than drinking a jigger of wine that is 12% alcohol.

And of course (to continue the alcohol analogy), we all know that the degree of our reaction to alcohol is not determined merely by a drink’s alcohol content, but also by how many drinks we consume. Drinking three jiggers of rum cause a greater reaction than drinking just one jigger.

But it gets even more complicated: Different people react differently to the same amount of alcohol. Depending on body weight, how much alcohol you’re accustomed to drinking, and other factors, one person may feel the effects of drinking those three jiggers much more than another person.

And so it is with gluten. Reactions to it vary from person to person, and those reactions are determined not merely by how much gluten is in a "gluten-free" product we consume, but also by how much of that product we consume.

How Can You Determine How Much Trace Gluten a Product Contains?

As with information about alcohol content, you would think that shoppers would be provided with reliable, meaningful information about the amount of gluten that’s in the "gluten-free" products they use. But in many cases, we aren’t provided with that information. I hope to help change that.

The quantity of gluten in a particular product can be expressed scientifically as a certain number of parts of gluten contained in each million parts of the product: parts per million, or ppm, of gluten. Another way to think of the concept of "parts per million" is that it is in effect a percentage of gluten in a particular product (for example, foods that contain 20 parts per million of gluten contain 0.002% gluten).

In August 2013, the FDA finalized regulations that would allow food manufacturers to place "gluten-free" labels on foods that contain less than 20 ppm of gluten. In addition, Canada considers 20 ppm to be "gluten-free", as do countries in the European Union.

However, many people react to food products that are labeled "gluten-free" but still contain less than 20 ppm of gluten. Manufacturers know this, and some voluntarily adhere to a more stringent testing standard than 20 ppm — typically, they use 10 ppm or 5 ppm.

Currently, it's not possible to test down to zero ppm of gluten. The most sensitive commercially available test can detect gluten down to 3 ppm, and that test reports anything lower as "undetectable."

However, for some of us, "undetectable" doesn't apply to our bodies — our bodies are quite capable of detecting gluten below that 3 ppm level. If you experience your typical glutening reaction to a food that tested "undetectable," you should assume your body is more sensitive than the most sensitive test available today, and that the food indeed contains gluten (albeit at levels below 3 ppm).

Finally (as if all this wasn't complicated enough already), rather than state a specific number of ppm of gluten in a product, the industry uses "less than" ranges. For example, a product is referred to as "20 ppm" if it contains less than 20 ppm of gluten. This means the product may contain anywhere from as many as 19 ppm of gluten down to zero gluten. As a practical matter, we should all assume the worst and treat that product as containing 19 ppm.

If we want to be sure a product contains less trace gluten, then we would want to know that it is considered a 10 ppm, 5 ppm or 3 ppm product. For ease of reference, I use the term "GF-20" to mean that a product contains less than 20 ppm of gluten, "GF-10" to mean less than 10 ppm, and so on.

You Might React When Someone Else Doesn't

Everyone's reaction is different. For example, depending on your sensitivity level, you might not react at all to a given quantity of GF-3 food, such as eating one GF-3 cookie. However, you might have a mild reaction to eating one GF-5 cookie, a greater reaction to one GF-10 cookie, and an even greater reaction to a GF-20 cookie.

And of course, as with alcohol, it’s not just how potent the cookie is, it’s how many you consume that can affect you. So even if you didn't react at all to eating one GF-3 cookie, you might have a reaction if you eat two or three GF-3 cookies.

You also might react even if someone else doesn't — that's why you shouldn't listen to people who tell you that "I didn't react, so it has to be perfectly gluten-free!" Everyone's reaction is different.

A Resource to Help Determine Gluten PPM Amounts

So it’s important that we know the ppm rating for a particular product before we use it. At present, that information is not generally displayed on product labels. However, I have culled from the companies information about those ratings and am presenting the information in what I call my Gluten Parts Per Million Table. (Note that I cannot and have not attempted to independently verify the accuracy of the companies' stated ppm levels.)

How any given person reacts to any given quantity of a product with any given level of gluten varies dramatically from person to person. It likely costs companies more to produce products with lower levels of gluten, and presumably, these higher costs are reflected in higher product prices. If you know that you do not react to GF-20 products, then why pay more for GF-10, 5 or 3 products? In other words, providing more ppm information actually may save some consumers money.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Diez-Sampedro A, Olenick M, Maltseva T, Flowers M. A gluten-free diet, not an appropriate choice without a medical diagnosis. Journal of Nutrition and Metabolism. 2019;2019:e2438934. doi: 10.1155/2019/2438934

  2. Roberts WC. Determining the quantity of alcohol consumed. The American Journal of Cardiology. 2012;110(5):761. doi: 10.1016/j.amjcard.2012.06.008

  3. Food labeling: gluten-free labeling of foods. Final rule. Fed Regist. 2013;78(150):47154-79.

  4. Cohen IS, Day AS, Shaoul R. Gluten in celiac disease-more or less? Rambam Maimonides Med J. 2019;10(1).:e0007. doi: 10.5041/RMMJ.10360

By Jane Anderson
Jane Anderson is a medical journalist and an expert in celiac disease, gluten sensitivity, and the gluten-free diet.