Are Oats and Oat Flour Gluten-Free?

Print Friendly, PDF & Email

Updated February 2021

Oats are a hot button topic within the celiac and gluten-free communities. Oats are not considered a top allergen, and in their pure form, oats are safe for the majority of people with celiac disease. Unlike wheat, barley, and rye, oats are not considered a source of gluten in many countries.  

The concern with oats is that they come into contact with gluten grains from the field to processing. The term for gluten grains getting into non-gluten grains during growth, harvest, transport, or storage is agricultural comingling and the proper term for gluten getting into non-gluten foods during processing is “cross-contact” (not cross-contamination which describes bacteria such as salmonella, not food particles). Read more about agricultural commingling in our article, Gluten in Your Food: Cross-Contact or Cross-Contamination?” 

Agricultural comingling and cross-contact with gluten are valid concerns with oats, leading to the question “Are these oats really gluten-free?”  

Here’s a breakdown of oats and oat processing to help clear up widespread confusion about the safety of oats as well as oat flour. 

Fact 1: Oats are not considered a gluten source in many countries.

As we mentioned above, oats are not typically placed in the same category as wheat, barley, or rye when it comes to gluten regulations. 

Canada, Europe, and many other countries follow a uniform set of guidelines to ensure food safety called Codex Alimentarius Standard_118-1979. The Codex includes oats in its definition of gluten grains. However, in a footnote, the Codex standard states: 

“Oats can be tolerated by most, but not all, people who are intolerant to gluten. Therefore, the allowance of oats that are not contaminated with wheat, rye or barley in foods covered by this standard may be determined at the national level.” 

Most European countries allow oats in products labeled gluten-freeCanada issued a Marketing Authorization in 2015 that allows the use of gluten-free claims for gluten-free oats, and foods that contain them, as ingredients. In this case, the oats must be specially grown or processed to ensure that they are gluten-free and are tested to have no more than 20 ppm of gluten grains.  

In Canada, the term “gluten-free oats” must clearly identify the oats wherever they are referenced, including in the list of ingredients. Note that in the U.S., the FDA does not allow any descriptions in the ingredient lists on packaged food labels. 

Exceptions to this rule are Australia and New Zealand, two countries that include oats as a restricted grain along with wheat, barley, and rye in any gluten-free products produced or sold in those countries.     

Fact 2: Oat processors have different methods to make sure that their oats are gluten-free.

There are two main ways that oat processors currently avoid or remove potential agricultural co-mingling with gluten grainsBoth ways can be used to produce gluten-free oat products, and the two methods are often combined: 

1. Purity Protocol takes place during the growing, harvesting, transporting, storageprocessing, and manufacturing of oats. This process consists of a non-regulated set of steps to address the early stages of oat production. 

2. Mechanical sorting takes place during the processing of the oats. A set of machines are used to sort oats to ensure proper size, shape, and color and to eliminate mold and other unwanted particles, including errant grains. Sorting happens after oats arrive at an oat processing facility, but in most cases the processor has limits on what level of gluten presence can be tolerated when the oats are received, and will reject oats with high levels of gluten grains. 

Some oat processors use Purity Protocol alone as an assurance their oats are gluten-free. Some processors use a combination of Purity Protocol followed by mechanical sorting. Otherrely on mechanical sorting to rid their oats of gluten grains. 

While there is still no consistency in producing gluten-free oatsmore consumers are demanding transparency in oat processing methods to feel confident the oats they are purchasing are safe to consume. Let’s dig into both of these methods of oat processing that take place prior to packaging. 

Purity Protocol

Purity Protocol is the term describing a method for producing gluten-free oats developed by Montana Gluten Free Processors, and later adopted by some U.S. and Canadian oat companies as a way to differentiate their oats from their competitors. The protocol consists of a set of steps growers and processors can take to minimize the risk of cross-contact between their oats and errant gluten grains. 

In order to create more consistency in carrying out Purity Protocol, Gluten-Free Certification Organization (GFCO) worked with oat processors to come up with an industry standard for Purity Protocol in 2017.  

Mechanical Sorting

Sorting oats by machines may sound like a process that could create more opportunities for cross-contact. The interesting thing about mechanical sorting, however, is that it is a very extensive process with many steps that can literally identify and remove gluten grains, getting oats that much closer to being truly gluten-free. And because of the intricacies of the process and the machine settings, oat producers are not using their sorting equipment for handling other grains, so the process is dedicated to oats.

Producers of mechanically sorted oats often also institute requirements on their growers to make sure that the starting oats have as little contamination as possible, and they perform visual examination of the oats (done by trained personnel) on receipt to make sure the incoming oats meet their requirements. This same type of visual examination is also performed at the end of the sorting process, to be sure the sort was effective and if an unacceptable level of gluten grains are identified during the visual review, the machines can be recalibrated with new parameters and the oats can be run through the system again.

Potential cross-contact can happen at any stage of Purity Protocol or Mechanical Sorting, but both methods are effective ways of producing gluten-free oats.

Fact 3: A thorough third-party certification process can help ensure a gluten-free product

The best way to know oats are gluten-free is to look for a third-party gluten-free certification mark, like the one used by GFCO. The requirements of certification are intended to help processors identify and remove potential risks of cross-contact with gluten. Many processors of Purity Protocol and mechanically sorted oats come to GFCO to have their oats certified. 

During GFCO certificationall procedures involved in oat processing are audited and oats are tested multiple times to verify that they are gluten-free. Testing alone does not guarantee oats are gluten-free because there are many steps before and after testing where cross-contact could happen if proper procedures aren’t followed.  

The GFCO certification process includes 80 requirements for product certification that apply to any product, including oats and foods containing oats. These requirements include: 

  1. Supplier review and approval 
  2. Purchasing protocols to make sure the materials purchased are gluten-free 
  3. Examination and review of incoming shipments to make sure they are correct and that there has been no gluten cross-contact 
  4. Correct storage of gluten-free and gluten-containing raw materials 
  5. Proper facility set-up to avoid cross-contact 
  6. Cleaning protocols and schedules 
  7. Visual examinations in addition to testing products 
  8. Ongoing review of processes, particularly when there are changes in the plant 
  9. Training of staff on gluten sources and health risks 

You can review all of the GFCO certification steps listed starting on page 48 of the GFCO Manual. 

GFCO also maintains stricter criteria for gluten-free products than the FDA, namely in the amount of gluten allowed in a product: the FDA requires less than 20 ppm whereas GFCO requires 10 ppm or less gluten content. GFCO will not certify any foods, including oats or foods containing oats in any form, unless there is a high degree of confidence that they are gluten-free because they’ve passed the many criteria to earn the GFCO certification mark. 

The safest oat products are those that have been certified gluten-free. While products labeled gluten-free should comply with the FDA definition of containing no more than 20 ppm of gluten, this is not third-party verified. 

What About Oat Flour?

Some people are concerned about oat flour and the chances of cross-contact taking place during the milling of the flour. Oat flour, like any processed and packaged product, can be tested for gluten.  

In fact, it is much easier to test for gluten in oat flour than in whole, unprocessed oat groats because if there are gluten grains present, they have been more evenly distributed throughout the flour. More even distribution means it is easier to detect gluten in much smaller samples taken for testing.  

GFCO recognizes that the distribution of gluten in a milled oat flour is not 100% uniform and requires manufacturers to test all oat ingredients multiple times as part of certification. 

The Bottom Line about Gluten-Free Oats

When in doubt about the safety of oats, look for a mark on the packaging that says “Certified Gluten-Free” for peace of mind or look for the new GFCO certification mark: 

Gluten-free consumers should be cautious of oat products that are not labeled or certified gluten-free. If an oat product is certified gluten-freethe certification mark verifies that the product is safe to eat. 

If someone believes they are sensitive to oats, they should consult with their physician before adding oats to their diet. If someone is sensitive to gluten or has been diagnosed with celiac disease, looking for a reliable certification on an oat product will offer the best assurances available that the product is safe. When one’s health is on the line, erring on the side of caution can be the best route, but understanding the science and the facts around gluten-free oats can help put their safety into perspective. 

More on Oats in a Gluten-Free Diet

The majority of information in the scientific literature supports the case that gluten-free oats are safe for the majority of individuals with celiac disease. Oats should only be introduced into the diets of people with celiac disease under the guidance of a personal healthcare team and in limited amounts.  

Why oats should be included in diet at all if there is any question as to their safety? Oats are a good source of nutrients that are often lacking in the gluten-free diet. Since the gluten-free diet is already limited, adding additional restrictions can have negative effects on quality of life. Thissue of oats can seem complex and confusing due primarily to the following factors: 

1. The risks of agricultural comingling and cross-contact: Unless certified gluten-free, oats may contain gluten-containing grains, potentially leading to the belief that the oats themselves are problematic. Gluten grains can still get into oats through wind, animals, and human error prior to processing. Over recent years, certified gluten-free oats – and products containing certified gluten-free oats or oat flour – have become more widely available, making this issue less prevalent.

2. Some people are sensitive to oats: Oats contain avenin, a storage protein that bears some similarities to the gluten found in wheat, rye, and barley. The amount is relatively small. Research on sensitivity to avenin generally indicates that avenin does not cause a reaction in the majority of celiac disease patients. Oats should be introduced in consultation with one’s healthcare team to monitor any potential issues.

GIG and GFCO will continue to monitor research and food safety issues regarding oats and will update this article accordingly. 

Terms Used in This Article

Agricultural Comingling – The inadvertent mixing of different grains due to shared planting and harvesting equipment, shared transportation and storage facilities, and other things like the activities of birds, wind, and weather. 

Cross-Contact – The proper term for gluten getting into non-gluten foods during processing is “cross-contact” (cross-contamination describes bacteria, such as salmonella, not food particles). 

Purity Protocol – Developed by Montana Gluten Free Processors and later adopted by some U.S. and Canadian oat companies as a way to differentiate their oats from their competitors. Purity Protocol takes place during the growing, harvesting, transporting, storage, processing, and manufacturing of oats. 

Mechanical sorting – A specialized process involving a complex system of machines calibrated to find and remove gluten grains. Mechanical sorting takes place in the latter part of oat processing. 


Disclaimer: The information on this website is for educational purposes only. Consult your healthcare team when considering this information. 

7 Tips for Avoiding Gluten Cross-Contact at Home