Why it contains gluten

Certified gluten-free vs "no gluten ingredients"

The short answer

These are three different claims, and only two of them are claims at all. A GFCO certification means an audited supply chain tested to 10 ppm. A plain "gluten-free" label means the manufacturer is legally on the hook for under 20 ppm. An ingredient list with no gluten grain on it means nobody has tested anything. It is the absence of a claim, not a quiet version of one. The gap between the second and the third is where almost every unverified verdict on this site lives.

How it works

Tier one: certification. The Gluten-Free Certification Organization, a programme of the Gluten Intolerance Group, runs what it describes as an 80-step verification process. GFCO reviews every ingredient, "Every ingredient used in certified products is reviewed by the GFCO team to make sure it is safe to use in gluten-free products", requires ongoing testing of ingredients, shared equipment and finished products with results submitted quarterly, and confirms compliance "during annual, in-person audits at every manufacturing facility where GFCO-certified products are made." It also runs "random sampling or 'surveillance' testing on hundreds of GFCO-certified products each year." The threshold is 10 ppm: any detection above it must be reported to GFCO immediately. The Gluten Intolerance Group describes the FDA's 20 ppm as "twice as lenient" as its own standard.

The practical content of a certification is not really the number. It is the audit. Certification is the only tier where somebody other than the manufacturer has walked the plant.

Tier two: the gluten-free claim. Under 21 CFR 101.91, a food bearing a "gluten-free" claim in the US must contain no gluten-containing grain ingredient, no ingredient derived from one that has not been processed to remove gluten, and under 20 ppm gluten in total. The claim is voluntary (the Celiac Disease Foundation notes that naturally gluten-free foods "may be labeled gluten-free. However, this is not required"), but once made, it is enforceable. The UK and EU work the same way at the same number: Coeliac UK's guidance is that "only foods that contain 20 parts per million (ppm) or less of gluten can be labelled gluten free."

An unlabelled product made by a company that also runs a gluten-free line is not covered by any of this. The claim attaches to the product, not the company.

Tier three: a clean ingredient list. No wheat, no barley, no rye on the panel, and no claim on the pack. This tells you what was deliberately added. It tells you nothing about the fill line, the shared conveyor, the reworked product from yesterday's run, or the flavouring house's own facility. And on a US label it cannot even tell you about deliberately added barley, because barley is not a declarable allergen.

Tier zero: a "may contain" advisory. Precautionary allergen labelling is voluntary and non-standardised. Coeliac UK's guidance to manufacturers is that "PAL statements are voluntary and should only be used if there is an unavoidable risk of allergen contamination which cannot be sufficiently controlled by segregation and cleaning." The US position is the same in practice: the advisory is a choice. Two consequences follow, and both matter. A "may contain wheat" line does not mean the product contains wheat. It means the manufacturer will not vouch for the line. And the absence of that line does not mean the plant is clean; it may only mean the manufacturer chose not to print one.

Where this catches people

"No gluten ingredients" gets read as a verdict. It is the most common error in this category, and the whole reason this site exists. The reasoning goes: nothing bad on the panel, no warning on the pack, therefore safe. Every step of that is an inference, and the last one is not supported by anything.

A missing claim gets read as a warning. This is the opposite error and it is just as wrong. Certification costs money, requires audits and creates legal exposure. Plain dairy, single-ingredient produce, bottled water and a two-line cream panel have never needed a seal and mostly do not have one. A dairy declining to certify half & half is telling you about its budget, not about your risk.

So the honest reading of a missing claim is: this has not been checked. Not "this is dangerous." Not "this is fine." It is genuinely unresolved, and for most low-risk categories the practical risk is low while remaining unverified. Those two facts coexist and a good page states both.

Mars Wrigley is the worked example. In consumer-care correspondence republished by celiac advocates, Mars states that it does not label its chocolate products gluten-free because those products either contain gluten, are made on machinery that also makes gluten-containing products, or are made in a facility that uses gluten elsewhere, and that regardless of whether a product carries a "may contain" statement, it is never labelled gluten-free, because the company cannot guarantee it. Mars also says it does not maintain a list of gluten-free chocolate products.

Read that last part carefully, because it destroys the usual workaround. On a Mars product, the absence of an advisory carries no information at all. The company has said so. This is why every Mars page on this site resolves to unverified unless a gluten grain is declared, no matter how clean the panel looks. Dove, Orbit, Hubba Bubba, Snickers-adjacent lines: same policy, same outcome.

Manufacturers who decline to test are a distinct case. When Ball Park's brand team was asked, the answer was that they do not promote or certify products as gluten-free because they do not test for gluten. That is not a company hiding a bad result. It is a company saying the result does not exist. Cross-contact on those lines is unmeasured, not measured-and-acceptable.

Certification marks are not interchangeable. A Certified Paleo seal does not test for gluten. A "grain-free" seal from the same body does, at 10 ppm. Organic, non-GMO and vegan marks say nothing about gluten. Coeliac UK's Crossed Grain and GFCO are gluten programmes; most other seals on a pack are not.

How to tell

1. Look for a certification mark first. GFCO's mark, Coeliac UK's Crossed Grain, or an AOECS-licensed equivalent. This is an audited 10 ppm and it ends the question.
2. Then look for the words "gluten free" as a claim. Front of pack, or in the allergen block. This is an enforceable 20 ppm.
3. Then read the panel for gluten grains. Wheat, barley, rye, malt, malt extract, brewer's yeast. Any hit is a hard no regardless of everything above.
4. Then decide what the silence is worth in this category. A two-ingredient dairy product with no claim is a different proposition from a candy made on a line that also runs a wafer bar. Ask what else the plant makes.
5. Do not treat "may contain" as a scale. It is binary and it is voluntary. Its presence is a refusal to vouch; its absence is not a promise.
6. If it matters, ask. "Is this product tested to the FDA's under-20-ppm standard, and is it made on shared equipment with wheat or barley?" gets a usable answer far more often than "is this gluten-free?"

Related questions

Is a certified product actually safer than a labelled one? On paper yes, a lower threshold plus annual plant audits plus quarterly testing plus surveillance sampling. Whether the difference is clinically meaningful for you depends on how much of your diet comes from processed food and how sensitive you are. For most people the labelled 20 ppm product is fine; for people who react at very low exposures, the audit is the point.

Does the FDA test products to enforce the 20 ppm rule? The claim is enforceable and FDA does sample, but there is no routine pre-market testing of every gluten-free product. The claim is a legal commitment the manufacturer makes and can be held to, not a certificate issued after inspection.

Why does this site publish unverified instead of guessing? Because "probably fine" and "confirmed fine" are different pieces of information and readers with celiac disease are entitled to know which one they have. A page that says nobody has confirmed this, here is why, and here is how to confirm it yourself is more useful than a coin flip dressed as a verdict.

Does a company's overall gluten-free programme cover an unlabelled SKU? No. The claim attaches to the individual product. A brand can run a certified line and an untested one in the same building.

What if a product is certified in one country and not another? Then you have information about one supply chain only. Formulations, plants and certification scope all vary by market, which is why we treat regional variants as separate products.

How we checked

Overall source tier: A on the certification half, GFCO is a certification body describing its own standard, which is exactly what tier A means. The Mars example is deliberately carried at tier D and flagged as such, and it is the reason the Mars verdicts are unverified rather than not-gluten-free.

Last verified: 13 August 2026. Certification scopes and manufacturer policies change. The pack in your hand outranks this page.

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