“May Contain”: The Codex Establishes When That Warning Is Actually Justified

“May contain traces of tree nuts.” That phrase is the most visible form of precautionary allergen labeling — and one of the most misused.

This precautionary allergen labeling statement appears on thousands of food product labels. Some manufacturers include it because there is a genuine cross-contamination risk on the production line. Others add it as a precaution, without any specific risk assessment behind it. And many simply copy it from other labels or carry it over from earlier product versions without ever reviewing it.

Furthermore, the Codex Alimentarius itself acknowledges in its new guidelines that precautionary allergen labeling has been used excessively or without adequate technical justification. That is precisely one of the problems these guidelines set out to correct.

Precautionary allergen labeling: what the Codex approved in July 2026

On 6 July 2026, at the 49th session of the Codex Alimentarius Commission held in Geneva, new guidelines on the use of precautionary allergen labeling (PAL) were adopted. They are integrated as an annex to the General Standard for the Labelling of Prepackaged Foods (CXS 1-1985).

Specifically, the standard they establish is clear: “may contain” cannot be a generic precautionary decision. For it to be justified, the manufacturer must be able to demonstrate two things.

First, that it has implemented adequate allergen management measures — cleaning procedures, line separation, controls in storage and transport, staff training — and that those measures have not been sufficient to eliminate the risk.

Additionally, a documented scientific risk assessment supports that conclusion. A documented assessment, not an informal estimate.

In other words, only when preventive measures have been applied and residual risk demonstrably persists does precautionary labeling make sense. If the risk can be controlled through appropriate procedures, the warning is not justified.

Furthermore, one significant innovation in these guidelines is the introduction of Reference Doses as standardised quantitative thresholds at global level. For the first time, they allow a more objective assessment of whether a residual risk is significant for most people with allergies. This is also the first time a reference dose has been established for cereals containing gluten — something the coeliac community and industry professionals had been awaiting for years.

What these guidelines are NOT: a binding rule in the EU

However, this distinction is important and worth stating clearly from the outset.

Codex guidelines are voluntary. They are not directly applicable in any country. Codex texts function as international technical references — and as such, the World Trade Organisation uses them to resolve disputes between countries on food matters — but they do not replace national or EU legislation.

In the European Union, the regulatory framework governing allergen labelling remains Regulation (EU) 1169/2011. This Regulation establishes the obligation to declare the fourteen mandatory allergens when present as ingredients, but does not specifically regulate precautionary labelling. In the EU, “may contain” remains voluntary and there is no harmonised binding standard for when it must be used.

Indeed, what these guidelines do is establish, for the first time, an internationally recognised technical benchmark backed by seven expert consultations from FAO and WHO. In practice, this carries real weight even without creating direct obligations.

Why it matters, even if it is not mandatory

There are two concrete reasons why these guidelines are relevant now, even for manufacturers operating exclusively in the EU.

First, the check concerns the day-to-day work of inspectors and auditors. Food control authorities and certification auditors already use Codex documents as technical references to assess whether a company’s allergen management systems are adequate. A manufacturer using precautionary labelling without documented assessment may not be in breach of current European Regulation. But it diverges from the international technical standard the Codex has just consolidated — and that standard is the one used as a reference during an inspection or audit.

Second, this is about long-term regulatory positioning. These guidelines represent a relevant international technical benchmark in the event of a future revision of European allergen standards. No one can predict whether or how the European Commission will incorporate them. This is, however, the most robust technical document that exists today on this subject — the kind that tends to shape regulatory review processes.

Ultimately, having documentation in order today is a technical management decision, not anticipation of an obligation that does not yet exist.

What lies behind a label that looks simple

There is an idea that underpins the entire logic of these guidelines and defines the approach we take at LegaleGo Regulatory:

A label is not validated by what is written on it. It is validated by the technical justification that exists behind it.

In practice, writing “may contain traces of tree nuts” takes a matter of seconds. Demonstrating that the warning reflects a real assessment requires documenting allergen management at the facility: cleaning procedures and their validation, line separation measures. When required, it also includes analyses confirming whether residual risk exists.

Consequently, the difference between the two situations — writing the phrase versus supporting it — is precisely what the Codex has just codified as the international technical standard.

This applies in the opposite direction too. A company that has implemented robust allergen management procedures and can demonstrate that the risk has been eliminated has grounds to remove precautionary labelling. The warning may have been on its product for years without any assessment to justify it. This gives the company grounds to remove it.

What makes sense to review now

In short, the point is not to adapt processes to a future standard that may or may not arrive. The point is to verify whether the precautionary labelling already in use has sufficient technical and documentary justification.

Concretely, the question worth asking for every “may contain” warning on a label is straightforward: is there a risk assessment behind it? Is it documented? Does it reflect what actually happens on the production line today — not five years ago?

In many cases, the answer is that the assessment does not exist, or that the available documentation is not up to date. Not because anyone decided against doing it, but because no one had ever requested it at this level of specificity.

The review covers allergen management in production — shared lines, cleaning procedures, suppliers, storage — and the traceability of that documentation. When the risk profile warrants it, verification analyses are included.

Moreover, the outcome of that work is not just a label that is more defensible in the event of an inspection. Moreover, it is a technical position the company can defend with distributors, sales platforms, or buyers who increasingly demand evidence behind manufacturer declarations.

At LegaleGo Regulatory, we work with manufacturers on exactly this type of review: examining what lies behind current labelling and assessing whether the technical justification is sufficient to sustain it. Our team does not carry out a superficial review of what the label says. We assess whether it can be defended. You may also find it useful to read about food supplement notifications in Spain.

LegaleGo Regulatory

Sources:
FAO/WHO — Codex adopts new guidance on “may contain” allergen labels
General Standard for the Labelling of Prepackaged Foods (CXS 1-1985)
ELIKA — New Codex guidelines on precautionary allergen labelling
Regulation (EU) 1169/2011 on the provision of food information to consumers