Editor’s Note (June 2026): This article has been updated to reflect current research, labeling regulations, and best practices for people with celiac disease and gluten-related disorders.
If you’ve spent any time in the gluten-free community, you’ve probably heard people question whether the FDA’s 20 parts per million (ppm) gluten threshold is truly safe for people with celiac disease.
After all, if laboratories can detect gluten below 20 ppm and some certification programs require even lower levels, why did the FDA choose 20 ppm? And is that threshold enough to protect people with celiac disease?
In this article, I’ll explain how the FDA arrived at the 20 ppm standard, what the research says about low-level gluten exposure, and why many experts continue to support the current gluten-free labeling guidelines. Please see my disclosures.
Understanding Gluten-Free Labeling
The Food Allergen Labeling and Consumer Protection Act (FALCPA), passed in 2004, requires food manufacturers to clearly disclose the presence of major allergens, including wheat, on packaged food labels.
In 2013, the FDA finalized its gluten-free labeling rule, establishing a national standard for foods labeled:
- Gluten-Free
- No Gluten
- Free of Gluten
- Without Gluten
Under the rule, a product may carry a gluten-free claim if it:
- Contains less than 20 parts per million (ppm) of gluten
- Does not contain wheat, barley, rye, or their crossbred hybrids as ingredients, unless those ingredients have been processed to remove gluten and the finished product contains less than 20 ppm gluten
It’s important to understand that gluten-free labeling is voluntary. Manufacturers are not required to label a product gluten-free, even if it meets the FDA definition.
It’s also important to understand that a food labeled gluten-free may still contain trace amounts of gluten. For example, a product testing at 10 ppm or even 19 ppm may legally carry a gluten-free claim.
The FDA’s less-than-20-ppm standard aligns with regulations adopted by many countries and international organizations, including the Codex Alimentarius, which helps guide global food standards.
Why 20 Parts Per Million?
The FDA didn’t randomly select 20 parts per million (ppm) as the threshold for gluten-free labeling. The agency reviewed scientific evidence, testing limitations, and real-world manufacturing practices before arriving at the standard.
According to the FDA, the 20 ppm threshold was chosen because:
- It is the lowest level that can be reliably detected in foods using validated testing methods.
- Research suggests that most people with celiac disease can tolerate trace amounts of gluten below this level without experiencing intestinal damage.
- The standard aligns with international gluten-free labeling regulations used throughout much of the world.
- It creates a practical framework that manufacturers can consistently achieve and verify.
One of the researchers who helped inform the FDA’s decision was Dr. Alessio Fasano, Director of the Center for Celiac Research at Mass General for Children.
In his book, Gluten Freedom, Dr. Fasano describes research in which adults with celiac disease in remission consumed varying amounts of gluten each day. Researchers found that participants consuming 10 milligrams (mg) of gluten daily did not experience measurable intestinal damage, while those consuming 50 mg per day showed evidence of intestinal injury.
These findings helped researchers estimate how much gluten people with celiac disease could safely consume and informed the FDA’s decision to adopt the current gluten-free labeling standard.
Researchers also found that a person could consume approximately 300 grams of gluten-free foods containing 20 ppm gluten and remain below the 10 mg daily gluten threshold identified in the study.
While no regulatory standard is perfect, the 20 ppm threshold remains grounded in the best available evidence and is widely accepted by celiac organizations, regulatory agencies, and food manufacturers around the world.
Dr. Fasano includes the following chart in his book to further explain how his team determined the 20 ppm gluten threshold.
What Does 20 ppm of Gluten Look Like?
One reason the FDA’s gluten-free labeling rule creates confusion is that most people have no idea what 20 parts per million (ppm) actually looks like in the real world.
Twenty ppm is a very small amount of gluten. To visualize it, imagine one million grains of sand. Only 20 of those grains would represent gluten.
Another way to think about it is this: a product labeled gluten-free may contain trace amounts of gluten, but those amounts are extremely small and generally considered safe for most people with celiac disease when consumed as part of a normal diet.
The National Celiac Association offers a helpful comparison. According to the organization, a person would need to consume a large quantity of foods containing 20 ppm gluten to approach the 10 mg daily gluten threshold identified in research studies. By contrast, a tiny crumb of regular wheat bread can easily exceed that amount.
This is why celiac experts often focus on overall gluten exposure rather than obsessing over whether a product contains 5 ppm, 10 ppm, or 19 ppm gluten. While those differences may sound significant, they are often less meaningful than avoiding obvious sources of gluten contamination altogether.
Is the 20 ppm Gluten Threshold Enough?
Many people in the gluten-free community have questioned whether the FDA’s 20 ppm standard should be lowered. After all:
- Some testing methods can detect gluten below 20 ppm.
- Some certification programs, such as GFCO, require products to meet standards below the FDA threshold.
- Devices like Nima may occasionally detect gluten at levels below 20 ppm.
- Many people with celiac disease continue to experience symptoms or fail to achieve complete intestinal healing despite following a gluten-free diet.
These are important considerations and have fueled ongoing discussion within the gluten-free community.
However, it’s important to understand that gluten thresholds are not based solely on what laboratories can detect. They are based on what research suggests is safe for the overwhelming majority of people with celiac disease while remaining practical for food manufacturers to consistently achieve and verify.
One of the biggest misconceptions is that if 20 ppm is safe, then 10 ppm must be safer and 5 ppm must be safer still. While that may sound logical, the research doesn’t currently demonstrate that lowering the FDA’s threshold would improve health outcomes for most people with celiac disease.
As Dr. Alessio Fasano noted in his In Defense of 20 Parts Per Million, regulatory thresholds should be based on evidence of harm—not simply advances in testing technology.
To date, there is no compelling evidence showing that foods containing less than 10 ppm gluten result in better outcomes than foods containing less than 20 ppm gluten for the vast majority of people with celiac disease.
That doesn’t mean the current system is perfect. No labeling system can eliminate all risk, and occasional manufacturing failures do occur. However, the available evidence suggests that the current FDA standard strikes a reasonable balance between consumer safety, scientific evidence, and real-world food production.
Bottom Line: Is 20 ppm of Gluten Enough?
For most people with celiac disease, the FDA’s 20 ppm gluten-free labeling standard is safe and effective. The standard is based on the best available evidence and is supported by major celiac organizations, researchers, and regulatory agencies around the world.
That doesn’t mean the system is perfect. Manufacturing errors can occur, and some individuals may be more sensitive to gluten than others. In addition, researchers continue to study why some people with celiac disease experience persistent symptoms or fail to achieve complete intestinal healing despite following a gluten-free diet.
However, it’s important not to assume that every lingering symptom is the result of trace gluten exposure or that lowering the gluten-free threshold from 20 ppm to 10 ppm or 5 ppm would automatically improve health outcomes.
For most people, focusing on overall dietary adherence, learning how to identify meaningful sources of gluten exposure, and maintaining a balanced approach to living gluten-free will have a far greater impact on health than worrying about the difference between 20 ppm and 10 ppm.
A truly zero-gluten diet is virtually impossible to achieve in the real world and may create unnecessary restrictions without providing additional benefit for most people with celiac disease.
The goal isn’t perfection. The goal is to stay safe, stay healthy, and maintain a quality of life that allows you to fully participate in the world around you.
Additional Reading:
Can You Be Too Gluten-Free? How to Balance Celiac Disease, Food Safety, and Quality of Life
Gluten-Free Labeling Laws Explained: How to Read Food Labels and Avoid Hidden Gluten
As someone who just got a reaction from eating a gluten free certified food, I think 20 ppm is too high. Gluten free should mean completely free of gluten.
When the new labeling began, my gut feeling right from the start has been…if I consume many products labeled GF in one day that have no more than 20ppm, I will be consuming much more than 20ppm. A friend of mine called to tell me she experienced that when she attended a gf vendor fair and she tested many products that were all labeled gf. She had a terrible reaction and got very sick that night. I feel anything labeled gf should be free of all gluten, which I’m sure is very difficult today for manufacturers and any food suppliers….Just my take!!
I have been reading/researching about gluten free options since I was medically diagnosed with Celiac disease in 2011. I thought I was crazy for many years because I kept getting sick eating GF labeled food until I came across an article informing me of the FDA’s 20ppm rule for “gluten free” labeling. Apparently, I am extremely sensitive to gluten (need 0ppm). Now I read ingredient labels very carefully and have had to learn the derivatives of sources, e.g. hydrolyzed protein. I have learned to trust a few brands. I wish the FDA would allow labeling like those in Australia so that the consumers could make a more educated decision about the products they buy. The FDA is not concerned about the ppm level and most likely will not ever change it, unless someone in their family gets sick (i.e. General Mills). The FDA does not care about the consumer, only his/her support of the economy.
I am happy to see you are considering the 20ppm standard. Many maintain that 20ppm threshold is arbitrary and more to do with the limits of testing at the time the rules were promulgated than actual scientific evidence. Are you familiar with a meta study performed by FDA published in 2011 looking at this very issue? It is entitled Health Hazard Assessment for Gluten Exposure in Individuals with Celiac Disease: Determination of Tolerable Daily Intake Levels and Levels of Concern for Gluten? The take away is that for many folks, there really is no safe level of exposure. The authors concluded: ‘The LOC values for gluten in food that correspond with these TDI values at the 90th percentile level of intake
are less than 1 ppm for both morphological (~0.5 ppm) and clinical (~0.02 ppm) adverse
effects. In sum, these findings indicate that a less than 1 ppm level of gluten in foods is
the level of exposure for individuals with CD on a GFD that protects the most sensitive
individuals with CD and thus, also protects the most number of individuals with CD from
experiencing any detrimental health effects from extended to long-term exposure to
gluten.’
I would also like to point out that the FDA rules do not require testing by food manufacturers when labeling a product gluten free. Only when challenged by a complaint is a manufacturer obligated to demonstrate that their product meets the 20 ppm standard.
Finally, I want to touch on the matter of follow-up endoscopy to assess gut healing. I am not sure how many people actually receive this although it is considered the standard of care: a person with an endoscopically confirmed celiac diagnosis is supposed to follow up in six months to gauge the efficacy of the GF diet. In my case, I have been on a dedicated GF diet since Jan 2015 and only recently did I manage to have the follow up procedure. Result? mucosa indicative of celiac disease and villous blunting. While I cannot be sure of the cause of villous blunting in September 2022 – was it the result of some accidental gluten ingestion in the weeks prior – overall I was very please to see that I had villi in the duodenum, albeit blunted.
My point in bringing up my personal experience in relation to the 20 ppm standard is that it is very likely that one can be exposed to gluten at cellularly damaging levels and not have any overt symptoms. I have read that it takes only 3 hours after gluten exposure to register an immunological reaction. And we all know what that means: autoimmune attack leading to potentially systemic inflammation. My concern is that the 20 ppm standard is too high to protect people from the effects of low level chronic gluten exposure. Consider for a moment that the target of the auto-immune response – the enzyme transglutaminase – is found throughout our bodies and not limited to the gut – and you can envision the wide ranging impact of even minute amounts of gluten.
Personally I know that 20ppm isn’t enough for me to not have symptoms.
I appreciate Dr Fasano point of not wanting needless restrictions on consumers or manufacturers. But he also set the standard for treatment for non responsive Celiac disease. The Fasano Diet for non responsive Celiac disease includes no prepackaged foods. (Including prechopped veggies or frozen fruit) due to the risk of gluten contamination. And it has amazing success rate of helping patients go into remission because they are getting glutened from gluten free foods!
There has to be a middle ground between Celiacs continuing to feel sick and having safe and tasty options.
Also how does Australia and New Zealand pull this off, while other countries deem it too restrictive?
Thank you for such great articles! I look forward to your email every Friday.
Look at that chart in the article. You can potentially be safe eating up to 10 mg of gluten each day. Ten milligrams is equal to approximately one-eighth of a teaspoon of flour. Ten milligrams translated into ppms is equivalent to the daily ingestion of more than a pound of gluten-free products containing 20 ppm of gluten.
Does consuming multiple gf products or servings allow gluten to accumulate above that ppm threshold on a daily basis or over time? If so the only safe diet for celiacs is to not consume processed gf foods at all. What’s the thinking on that?