What the adjusted gluten reference dose means for precautionary allergen labeling

What an allergen “Reference Dose” really means — in plain English

Precautionary labels are notoriously confusing for consumers, AND for many people inside the food industry. Reference doses (RfDs) aim to make them simpler.

If you’ve ever stood in a grocery aisle staring at a “may contain gluten” or “produced in a facility that handles eggs” label and wondered what on earth it really means, you’re not alone. “May contain” warnings or precautionary labels (PAL) are supposed to be used as a last resort. They are meant for use only after a manufacturer has determined that there is no feasible way to eliminate the risk of allergenic cross-contact — they are not meant to replace GMPs or help a food manufacturer “cover their bases.” In theory, PAL should help consumers stay safe. In reality, they often create confusion.

Increasingly, experts from around the world have been encouraging use of a tool called a reference dose (RfD) when considering precautionary allergen labeling and recall decisions.  

This sounds — and is! — technical. But it’s not hard to understand. This post breaks it down in everyday language.

FAO/WHO experts recently recommended adjustments to the gluten reference dose used in determining  PAL, so we’re going to use gluten as an example below. However! This information applies to allergens / the idea of reference doses generally. 

Experts have suggested updating the reference dose for gluten for in a risk-based determination of using PAL. To better-include individuals with celiac disease (instead of strictly those with a wheat allergy) and create a safe, uniform framework, they suggest switching from 5mg total wheat protein to 4mg gluten.  

First: What IS a “reference dose” or RfD?

A reference dose is a predetermined amount of something — in this case, the amount of gluten an affected individual could potentially ingest from one food in one sitting without risking their health. 

Is a 20 ppm (20 mg/kg) a “reference dose”?

No. A reference dose is a concrete amount. It is NOT a ratio. Two item could contain gluten in the same concentration but if they are ingested in different amounts — they would pose different risks to the person eating them.

For example, imagine a powdered dietary supplement with a standard serving of one 10g scoop. Now imagine there was an unavoidable risk of cross-contact, and the powder could contain up to 15ppm of gluten. This means that in a kilogram of powder, there could be 15mg of gluten. 

A person taking one scoop (10g) of powder would not ingest 15mg of gluten. They consumed 0.01 kilograms of supplement, which could mean up to 0.15mg of gluten.  Even if a person chose to have three times the recommended amount of supplement — they would still consume less than 1mg gluten. This item would not require PAL. 

Now imagine an ice cream with the same unavoidable risk: up to 15ppm of gluten. While the printed serving size might be half a cup of ice cream, we all know that’s not realistic. So how much gluten could a person accidentally ingest if they ate a full pint of this ice cream?  

A kilogram of this ice cream could contain up to 15mg of gluten. Assuming the pint weighs 475g — almost half a kilogram — the full pint could have more than 7mg of gluten. This is above the suggested 4mg RfD. This ice cream should have PAL. 

What DOESN’T the gluten RfD address?

• It doesn’t apply to foods that intentionally contain gluten.
• It doesn’t change the definition of “gluten-free” or the validity of the  20mg/kg (20 ppm) threshold for gluten-free foods.
• It doesn’t tell companies how much gluten they’re allowed to have in their products.
• It is not a recommended intake level or “safe” amount of gluten

Instead, it answers one question:

At what theoretical level of accidental gluten cross-contact should a food company consider adding a label warning like “may contain gluten”?

After reviewing all the science, the expert group recommended a 4 mg gluten reference dose. This is the threshold above which, if gluten were accidentally present in a realistic serving of a food, a person’s total daily intake could become a problem.

It’s like budgeting. While data indicates most people with celiac disease can tolerate a few mg of gluten per day without intestinal damage (likely around 10mg), this isn’t true of everyone and it doesn’t address the needs and sensitivities of people with wheat allergy. Additionally, cumulative gluten ingestion over time can be a problem for people with celiac disease. The new 4 mg reference dose helps prevent accidental exposure from multiple foods adding up over time.

So what does this mean for labels?

Right now, companies are inconsistent. Some put “may contain” on almost everything (to protect themselves), while others rarely use precautionary labels.

Adhering to a single risk-based reference dose aims to fix this. It could create better, clearer, and more consistent labeling.

• If a food might contain MORE than 4 mg of accidental gluten in the amount a person could conceivably eat in one sitting, companies should consider using a precautionary label.
• If the possible  ingested gluten is LESS than 4 mg, then a warning label probably isn’t needed.
• And to repeat — NO — this does NOT change “gluten-free” standards, rules or advice.  

Why this matters for consumers

Better reference doses and clearer rules:

• Reduce confusing “may contain” warnings
• Help people with celiac disease and wheat allergy better judge risk
• Improve trust in labels
• Encourage companies to assess cross-contact more methodically

The new gluten reference dose is a guideline to help companies decide when to add a precautionary label. It doesn’t change gluten-free rules — it just makes warnings more consistent and more meaningful.