Understanding the 'Gluten-Free' Standard: How Many Parts of Gluten Are Needed to Be Gluten-Free?

November 11, 2025 •

3 min read

According to the U.S. Food and Drug Administration (FDA) and other international standards like the Codex Alimentarius, a food product must contain less than 20 parts per million (ppm) of gluten to be voluntarily labeled 'gluten-free'. This threshold answers how many parts of gluten are needed to be gluten-free for the safety of those with celiac disease.

Quick Summary

The international standard for a product to be considered gluten-free is less than 20 parts per million (ppm) of gluten. This minimal trace amount is considered safe for the vast majority of individuals with celiac disease and other gluten sensitivities.

Key Points

The 20 PPM Standard: For a product to be labeled 'gluten-free' in many countries, it must contain less than 20 parts per million (ppm) of gluten, a level deemed safe for most with celiac disease.
Not a Zero-Gluten Standard: The 20 ppm threshold is not a measure of zero gluten, but a scientifically determined limit that accounts for trace amounts.
International Consistency: The 20 ppm limit is consistent with international guidelines set by the Codex Alimentarius Commission.
Managing Cross-Contact: The 20 ppm regulation is designed to address potential gluten cross-contamination during manufacturing and preparation.
Individual Sensitivity Varies: Some highly sensitive individuals may react to gluten levels below 20 ppm, so personal vigilance is still crucial.
Labeling and Certification: While the 'gluten-free' label is voluntary, using a third-party certified product can provide an extra layer of assurance.

What Does 20 Parts Per Million Actually Mean?

To understand how many parts of gluten are needed to be gluten-free, one must first grasp the measurement. Parts per million (ppm) is an incredibly small unit of measurement, equivalent to 20 milligrams of gluten per one kilogram of food (20 mg/kg). In contrast, a single slice of conventional wheat bread can contain thousands of milligrams of gluten. The 20 ppm standard signifies a minuscule, trace amount. This specific threshold is used because it's the lowest amount consistently detectable by reliable scientific methods, and research indicates most people with celiac disease can tolerate this quantity without adverse health effects.

The Science Behind the 20 ppm Threshold

The 20 ppm standard is an evidence-based consensus among international food safety organizations, such as the Codex Alimentarius Commission. Clinical studies suggest a daily gluten intake of less than 10-50 mg is generally safe for most individuals with celiac disease. While consuming small amounts from multiple products meeting the 20 ppm standard is unlikely to exceed this safe daily intake, caution is advised. However, a small number of highly sensitive individuals may react to even lower traces of gluten.

Cross-Contamination and the Gluten-Free Label

Preventing cross-contamination (or cross-contact) is a major challenge for gluten-free manufacturers. This occurs when gluten is unintentionally introduced to a gluten-free food, for example, through shared equipment. The 20 ppm standard takes this risk into account, requiring manufacturers to implement strict controls to ensure labeled products stay below this limit, even with potential cross-contact. While some certification programs require lower levels, 20 ppm is the legal standard for labeling.

Practical Steps for Reducing Cross-Contamination at Home

Minimizing cross-contact is crucial in households with both gluten-free and gluten-containing foods. Effective strategies include:

Dedicated Equipment: Use separate toasters, cutting boards, and colanders for gluten-free items. Research shows cooking gluten-free pasta in shared water can lead to unsafe gluten levels.
Separate Condiments: Use individual containers or clean utensils for shared spreads to avoid crumb contamination.
Storage Practices: Store gluten-free items on higher shelves to prevent accidental spills from gluten-containing products.
Thorough Cleaning: Wash all shared surfaces and utensils diligently with soap and hot water to remove gluten residue.

How to Read Food Labels for Gluten-Free Products

While the 'gluten-free' label is reliable, it is a voluntary claim, making consumer vigilance important.

Look for these indicators on packaging:

'Gluten-Free' Certification Seal: A third-party seal, such as the Crossed Grain symbol, indicates additional oversight and testing, often ensuring gluten levels are well below 20 ppm.
Ingredient List: Always check for common gluten sources like wheat, rye, barley, malt, or brewer's yeast.
'May Contain' Warnings: Be cautious of advisory statements like 'made on shared equipment with wheat.' Although not FDA regulated, manufacturers are still responsible for ensuring the labeled product meets the 20 ppm rule.

Comparison of Gluten-Free Labeling Standards


Standard	Threshold	Region	Comment
Codex Alimentarius	≤ 20 ppm	International	A global standard adopted by many countries.
United States (FDA)	< 20 ppm	US	Legally defined for voluntary labeling of most foods.
European Union	≤ 20 ppm	EU	Part of Regulation (EU) No 828/2014, covering pre-packaged and catering foods.
Very Low Gluten	21-100 ppm	EU	A separate, regulated category for products made with processed gluten-containing ingredients.
Australia/NZ	Not Detectable	Australia/NZ	Historically a stricter 'no detectable' standard, though harmonizing with Codex standards is an ongoing discussion.

Conclusion

To be labeled 'gluten-free,' a product must meet the strict standard of containing less than 20 parts per million of gluten. This level is widely accepted as safe for most individuals with celiac disease and is a key benchmark for food safety and labeling. While it doesn't mean zero gluten, the 20 ppm standard represents the lowest reliably detectable level and poses minimal risk to most sensitive individuals. Understanding this standard helps consumers make safe dietary choices. For more information on celiac disease, the Celiac Disease Foundation is a helpful resource.

Frequently Asked Questions

The 20 ppm standard was chosen because it is the lowest level of gluten that can be consistently and reliably detected with scientifically validated testing methods. Additionally, this amount is tolerated without adverse health effects by most individuals with celiac disease.

Parts per million (ppm) is a tiny unit of measure. 20 ppm is equivalent to 20 milligrams of gluten per one kilogram of food. To put it another way, if you were to consume a kilogram of a food that tested right at the 20 ppm threshold, you would have consumed only 20 milligrams of gluten.

No. 'Wheat-free' means a product contains no wheat, but it may still contain other gluten-containing grains such as barley or rye. A 'gluten-free' label confirms the product meets the less than 20 ppm standard, regardless of the grain source.

Cross-contamination, or cross-contact, is the unintentional introduction of gluten into a product. The 20 ppm standard is meant to account for this. Manufacturers labeling products 'gluten-free' must have procedures in place to prevent or limit cross-contact to ensure the final product is below 20 ppm.

For distilled spirits and wines, a 'gluten-free' label is generally safe. However, malted beverages like beer that are 'crafted' or 'processed to remove gluten' are not considered safe for those with celiac disease, as testing is not yet reliable for fermented products.

Oats are naturally gluten-free, but they are often cross-contaminated during harvesting or processing with wheat, rye, or barley. Therefore, unless oats are specifically certified and labeled as gluten-free, they should be assumed to be unsafe for a gluten-free diet.

Even with a 'gluten-free' label, it's wise to check for common hidden sources. Look for ingredients such as malt, brewer's yeast, or 'natural flavors' where the source is not specified. Reading the full ingredients list and the 'contains' allergen statement is key.