In the U.S., food makers must label the top 9 allergens when they’re among ingredients of a packaged food. But when it comes precautionary labels – such as “may contain” or “made in a facility with” – those warnings for possible allergen exposure in manufacturing are voluntary.
There are no standards governing these precautionary allergen labels (PAL). Some manufacturers use them, others don’t. The result is that the consumer is in the dark about the true degree of allergy risk.
Now, the U.S. Food and Drug Administration is exploring the use of allergen thresholds as the precautionary labeling solution. A threshold is the amount of an allergenic protein a person with an allergy can consume before having symptoms.
The FDA held public meetings in February 2026 to discuss how thresholds could be used as risk assessment tools. The public is invited to submit comments about food allergen thresholds and labeling here on the Regulations.gov website until May 19, 2026.
To help inform your thoughts, Allergic Living offers a Q&A below with food safety consultant Steven Gendel, PhD. He shares candid opinions on the pros and cons of threshold allergen labeling.
Gendel knows allergens, food manufacturing and allergen regulations thoroughly. He was the original FDA food allergen coordinator, and worked for two decades on science and policy at the agency. He has advanced training in risk assessment, food law and preventive controls.
Allergen Thresholds: Years in the Making
First, though, a little background on how we’ve arrived at thresholds. The international body called the Codex Alimentarius Commission has been working for years on standardizing advisory labels through research and meetings. (The commission oversees what’s known as the Food Code, a collection of global food standards and guidelines.)
A Codex committee suggested in May 2023 that to standardize PAL, the “may contain” labels should only be used based on risk assessment that is determined by threshold levels.
Under threshold labeling, a food would not need to be completely allergen-free to avoid a precautionary label. But it must be below the established limit.
Sensitivity to threshold levels varies from person to person. However, newer food challenge and oral immunotherapy studies allow researchers to estimate a dose at which 95 percent of people with a given allergy are unlikely to react. Also called a “reference dose,” it falls between 1 and 5 milligrams (mg) for most top allergens.
Proposed reference doses are 1 mg for walnut, pecan, cashew, pistachio, and almond; 2 mg for peanut, egg, milk or sesame; 3 mg for hazelnut; 5 mg of wheat or fish; and 200 mg of shellfish. They were developed by the Food & Agriculture Organization (FOA) of the United Nations.
Calls for a Mandatory U.S. System
During the FDA meetings in February 2026, scientists, allergists, food industry representatives, and patient advocates mostly supported the concept of using thresholds for labeling.
For example, Dr. Brian Vickery, chief of the Division of Allergy and Immunology at Emory University, noted that a threshold-based approach “grounded in the best science” would provide more clarity. “I see this as a big step in the right direction,” he said.
Regulators also pointed to the risk-based system in Australia during the February meeting. The Voluntary Incidental Trace Allergen Labelling (VITAL) program uses allergen reference doses to guide precautionary labels.
However, the Australian labeling system is voluntary, which was cause for concern for meeting participants. Several stressed that a mandatory system is necessary in the U.S.
As with any controversial topic, not all experts are on the same page. While the general consensus is that the inconsistent allergen warning labels need to change, how that is accomplished is up for debate.
Following is Allergic Living’s recent discussion with expert Steven Gendel. Our discussion explored his opinions about the possible use of food allergen thresholds as a way to fix the current unreliable system for allergen warning labels.
Q&A on Precautionary Label Thresholds with Steven Gendel, PhD
What is the benefit of using thresholds to determine PAL statements?
Steven Gendel: This discussion is sorely needed. The current system doesn’t work for either side – industry doesn’t know what to do, and the consumers don’t know what the warning labels really mean.
Right now, PAL statements are being used in situations with no (or very low) levels of cross-contact and not being used in other situations with high levels of cross-contact. Setting a threshold is expected to correct both problems and provide more accurate information to consumers.
While I have concerns, it is important that we do something. If this is the best we can do, maybe we need to do it.
It’s a problem and it needs a solution. The data the FDA is using from an expert global committee may be the best hope we have for moving toward a solution.
What is your biggest concern about using thresholds for allergen labeling?
Gendel: My biggest concern is that much of the data used by the FAO panel is secret. [The UN agency called the Food and Agriculture Organization oversees the Codex Commission.] That means no one can check the calculations, analyze them differently, or look for additional patterns. This seems to ignore the importance in science of replication. That’s especially so for data used to set public health policy.
Without knowing the data and without really understanding its impact, I think we’re moving too fast. Even if I agreed 100 percent with the calculations, I would still be uncomfortable about the fact that nobody else could reproduce them or look at them. It is the secrecy that makes it impossible to reproduce. The statistical techniques are state-of-the-art, but other experts could do the same type of analyses if they had the same data.
In addition, it’s not a simple implementation. For example, companies need to know how much of the allergen is present in their food and how much of a food people eat.
A reference dose has been determined for each top allergen based on the concentration of the protein in the product. But what serving size is factored into that threshold determination? For example, if a person eats a single-serving bag of chips from a vending machine, they will have a low exposure. However, if they eat a lot of chips from a “family-size” bag, they will have a high exposure.
The FDA standard “serving size” used for nutrition labeling is the same in both situations. But the risk to a sensitive consumer is very different. It is not clear how a manufacturer should take this difference into account when deciding whether to use an advisory label.
[Gendel is also concerned about the lack of access to allergy specialists, which would limit the ability for consumers to learn their own tolerance level.]
If you were still at the FDA, what would you be asking the expert panel for, especially regarding the data?
Gendel: If I were still at FDA, I would have many questions. For example, I would like to know how many of the patients who were tested had allergies to multiple foods? Were those patients equally sensitive to each food? For foods like milk that come in different forms (liquid whole milk, nonfat dry milk, casein, etc.), are consumers equally sensitive to all forms?
Is the economic status of individual patients or their geographic origin related in any way to their sensitivity? It may be that the data are not sufficient to answer these and similar questions; in that case these uncertainties should be considered in establishing thresholds.
How can thresholds answer the need for clarity in allergen labeling for industry and consumers?
Gendel: This system will only work if the implementation is mandatory. Otherwise, consumers will still not have clear information.
The mandatory process would be for FDA to require manufacturers to carry out an assessment about whether the product has an allergen that is above or below the threshold. If it is below the threshold, the company can’t use a “may contain” and if it’s above the threshold, they have to use a “may contain.” That’s the ideal.
If it’s voluntary, how do people know whether the lack of a statement is because there is no allergy present, or because the company hasn’t bothered to do anything? If it isn’t something that is applied uniformly, then we’re back in the same boat again.
How would you explain to a food allergy mom what the use of thresholds will mean to her family?
Gendel: With a clear, mandatory system, a food allergy mom would know that the absence of an advisory label could be trusted to mean that unintended allergen presence was absent or very low.
She would also know the presence of an advisory label was the result of a technical evaluation carried out in the same way by all companies. This puts the power to make informed choices about what to buy, or not buy, in her hands.
How has food testing improved to allow manufacturers to test for the lower concentrations of allergens?
Gendel: In the last decade, the sensitivity and quality of allergen tests have improved tremendously. I don’t think that sensitivity is a problem for most food allergens. What will be important is figuring out how much testing is needed to ensure consumer safety.
How can the FDA involve more feedback from consumers? What should consumers be asking?
Gendel: I have to hand it to FDA, they’re asking for public input. Codex is adopting these. The FDA will likely go along with what Codex says to be consistent with international standards.
I absolutely think that more input is needed from the affected consumers. Importantly, it’s also needed from people with expertise in consumer communication and behavior.
The FAO expert panel members were highly skilled risk models and assessors. None are trained to understand consumers’ concerns, but they made some important assumptions about what consumers want and what is good for them.
For example, the scientists seem to have reached a consensus that “may contain” is the best wording to use for a PAL statement. Yet, no one has done any research on consumer preferences.
In all the comments, the FDA will want something professionally useful. It isn’t helpful to just say, “We do or don’t want this.” Comments should articulate what specifically is needed. Be specific. Give the agency some guidance of what they need to do.
Editor’s note: Reminder that comments on food allergen thresholds can be submitted here on the Regulations.gov website until May 19, 2026.
Related Reading:
FDA Weighs Moving Food Allergen Warnings to Thresholds System
Food Allergy Experts Weigh In on: Global ‘May Contain’ Labels
Mom’s Warning of Son’s Reaction Triggered Jolly Rancher Recall
