Voluntary "May Contain" Allergen Warnings Under FALCPA
"May contain" advisory warnings are voluntary under FALCPA — but that doesn't mean they're unimportant. Here's how to use them responsibly.
"May contain" advisory statements — such as "may contain traces of peanuts" or "produced in a facility that also processes tree nuts" — are not required by FALCPA. They are voluntary. But voluntary doesn't mean optional for responsible food businesses, and how you use them matters.
Why "May Contain" Warnings Exist
Advisory warnings exist to communicate cross-contact risk to allergic consumers — the risk that a product may contain trace amounts of an allergen not intentionally added, due to shared equipment or facilities. This is distinct from an allergen that is a deliberate ingredient, which must always be declared under FALCPA.
When to Use Them
Use advisory warnings when there is a genuine and documented cross-contact risk. This means a shared production line, shared cleaning protocols, or demonstrated environmental contamination. "May contain" statements should not be used as a blanket disclaimer to avoid proper allergen management — this is sometimes called "precautionary labelling" and the FDA has criticised its overuse as it erodes consumer trust and makes the warning meaningless.
Common Advisory Formats
Common formats include "May contain [allergen]", "Produced in a facility that also processes [allergen]", and "Made on shared equipment with [allergen]". The FDA has no prescribed format for these voluntary statements, but they should be clear, specific, and not positioned in a way that could be confused with a mandatory "Contains" declaration.
Advisory Warnings on Your Shopify Store
If your physical product carries advisory allergen warnings, your Shopify product pages should reflect this. Customers with severe allergies will often search for "may contain" information before purchasing online — making this information visible on your product page can prevent both a dangerous purchase and a negative review.
Display complete allergen information including cross-contact warnings on your Shopify store.
The Difference Between Cross-Contact Risk and Ingredient Declaration
Understanding the distinction between a cross-contact risk and an intentional ingredient is foundational to using advisory warnings correctly. Under FALCPA, if a major allergen is deliberately added to a product — even as a minor flavouring or processing aid — it must be declared in the ingredient list or in a separate "Contains" statement. Cross-contact is different: it refers to the unintentional presence of an allergen introduced through shared equipment, shared facilities, or inadequate cleaning procedures between production runs. The advisory warning is the mechanism used to communicate that second, unintentional category of risk.
What makes this distinction practically important is that the two types of risk carry different regulatory weight and different consumer expectations. A consumer reading a "Contains" statement is receiving a legal declaration backed by FALCPA. A consumer reading "may contain" is receiving a voluntary disclosure that reflects your manufacturing environment. If your facility genuinely processes peanuts on adjacent equipment, an allergic consumer deserves to know that — and conflating voluntary and mandatory declarations by placing them in the same typographic style or location on your label creates confusion that can have serious consequences.
For Shopify merchants selling food products, this means your online product descriptions should be structured to separate mandatory ingredient-level allergen declarations from advisory cross-contact statements. Presenting them together without distinction can mislead customers into treating a precautionary warning as a mandatory one, or vice versa. Clear structure — a dedicated allergen section that distinguishes "Contains" from "May Contain" — helps customers with allergies make accurate, informed decisions before they complete a purchase.
How to Assess Whether an Advisory Warning Is Warranted
Before adding an advisory warning to any product, food businesses should conduct a documented allergen risk assessment. This is not a bureaucratic exercise — it is the evidence base that justifies the language you are putting on your label. A risk assessment should examine your ingredient sourcing (do any suppliers share facilities with allergen-containing products?), your internal production sequence (are allergen and non-allergen products made on the same lines?), and your cleaning validation data (does your current cleaning protocol reliably remove allergen residues to below detectable thresholds?). If the answer to any of these questions introduces genuine uncertainty, an advisory warning is appropriate.
The FDA's position — and the broader consensus among food safety professionals — is that "may contain" statements should reflect actual, assessed risk rather than theoretical possibility. Adding a blanket "may contain" warning to every product regardless of your manufacturing controls undermines the credibility of the warning across your entire range. Consumers with severe allergies learn quickly to discount warnings that appear on every product from a given brand, including products where the risk is real. The warning only functions as a useful communication tool when it is applied selectively and accurately.
Smaller food businesses selling through Shopify — particularly cottage producers or businesses using co-manufacturers — may find allergen risk assessment more difficult because they have less visibility into their co-manufacturer's facility practices. In these cases, it is entirely appropriate to request allergen management documentation from your co-manufacturer and reflect their disclosed risks in your own advisory labelling. If your co-manufacturer processes tree nuts and cannot confirm segregation, your product label and your Shopify product page should say so. Passing that risk information through to the consumer is both the ethical and the commercially prudent approach.
Advisory Warnings and Consumer Trust
There is a well-documented tension in precautionary allergen labelling between providing complete information and creating warning fatigue. Research into consumer behaviour among allergic individuals consistently shows that when "may contain" warnings are overused — appearing on products with no realistic cross-contact pathway — allergic consumers begin to ignore them, including on products where the risk is genuine. This is the core reason the FDA has raised concerns about indiscriminate precautionary labelling, and why food safety advocates argue that advisory warnings should be reserved for real, assessed risk rather than applied defensively.
For your Shopify store, this consumer trust dimension translates directly into commercial outcomes. If a customer with a peanut allergy visits your product page and sees "may contain peanuts" on a product that is manufactured in a completely peanut-free facility, you have potentially lost a sale you could have made safely. Worse, if the same customer sees that warning on every product in your catalogue regardless of the actual risk profile, they may conclude your allergen information is not reliable and take their purchasing elsewhere. Accurate advisory labelling — applied where warranted, omitted where not — is not just a safety practice; it is a brand trust practice.
The practical implication for online food retail is that your Shopify product pages should reflect the same level of allergen specificity as your physical labels, and that specificity should be grounded in your actual manufacturing data. A product page that simply states "may contain allergens" without naming the specific allergen, or that copies a generic disclaimer across all products, is doing the bare minimum — and the bare minimum in allergen communication is rarely enough for consumers whose health depends on accurate information. Detailed, product-specific advisory statements build the kind of credibility that keeps allergic consumers coming back.
Keeping Advisory Statements Consistent Across Label and Listing
One of the most common compliance errors food businesses make when selling through Shopify is allowing their online product listings to fall out of sync with their physical labels. This happens for understandable reasons — labels are updated after a formulation change or a new co-manufacturer agreement, but the Shopify product description is not updated at the same time. For mandatory FALCPA declarations, this inconsistency can carry regulatory risk. For advisory warnings, it creates a different but equally serious problem: a customer may make a purchasing decision based on an advisory statement on your website that no longer reflects your current manufacturing environment.
Establishing a process for synchronising label updates with your Shopify product pages is therefore part of responsible allergen management, not just a nice-to-have housekeeping task. When you update a physical label — whether to add an advisory warning, remove one, or change the format — that update should trigger a corresponding review and update of the relevant Shopify listing. Building this into your internal change-management process, however informal, prevents the drift that creates liability and consumer risk.
Tools like Allergen Matrix are designed to help Shopify merchants manage allergen information across their product catalogue in a structured, consistent way. Rather than maintaining allergen data in scattered product descriptions that are easy to overlook, a dedicated allergen management tool lets you update cross-contact information centrally and ensure it is displayed consistently across your storefront. For businesses with a growing catalogue or frequent formulation changes, this kind of systematic approach is far more reliable than manual description editing, and far more visible to the customers who need the information most.
Regulatory Direction of Travel on Precautionary Labelling
While "may contain" advisory statements remain voluntary under FALCPA as it currently stands, the regulatory and legislative environment around precautionary allergen labelling is evolving. There is ongoing discussion in the food safety community — and some movement at state level in the US — about whether standardised formats or threshold-based rules for advisory labelling should be introduced. The UK, following Brexit, has been exploring greater specificity requirements for precautionary labelling. Australia and New Zealand have implemented the VITAL system, which provides a science-based framework for determining when a "may contain" warning is warranted based on quantified risk thresholds. These international developments are worth monitoring even for US-focused brands, particularly those that export or sell across borders through Shopify's international commerce tools.
The direction of travel in most regulatory frameworks is toward greater specificity, greater consistency, and greater accountability in how food businesses communicate allergen risk. Voluntary today does not necessarily mean voluntary indefinitely, and businesses that have already invested in robust allergen management practices — including structured, accurate advisory labelling on both physical products and online storefronts — will be better positioned to adapt as requirements tighten. Building good habits now, when the standards are voluntary, is considerably less disruptive than retrofitting compliance after a regulatory change.
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SaltAI Team
SaltAI builds focused Shopify apps for food merchants and general merchants. Every app is tested in production at a real food store — including Vanda's Kitchen — before it ships.