What difference does a food label make? A whole heck of a lot, according to the Food and Drug Administration. Which means if your product doesn’t abide by federal guidelines, it can’t masquerade as something it’s not. As such, the FDA is warning the makers of “Just Mayo,” a vegan-friendly spread, that it can’t call itself mayo because mayonnaise contains eggs, which its product does not.

Back at the end of last year, Hellmann’s maker Unilever backed off on a lawsuit it’d filed against Hampton Creek over the mayo/not mayo issue, noting that it yanked the suit “so that Hampton Creek can address its label directly with industry groups and appropriate regulatory authorities.”

Eight months later, the appropriate regulatory authorities have come a’knocking, by way of a warning letter from the FDA to Hampton Creek, dated Aug. 12 and posted online on Tuesday. The letter addresses “Just Mayo” and “Just Mayo Sriracha” products.

“The use of the term ‘mayo’ in the product names and the image of an egg may be misleading to consumers because it may lead them to believe that the products are the standardized food, mayonnaise,” the FDA said, which must contain eggs by definition.

“Additionally, the use of the term ‘Just’ together with ‘Mayo’ reinforces the impression that the products are real mayonnaise by suggesting that they are ‘all mayonnaise’ or ‘nothing but’ mayonnaise,” the FDA adds, though again, the products aren’t technically mayonnaise. They also include “contain additional ingredients that are not permitted by the standard of identity for mayonnaise, such as modified food starch,” the agency notes.

The FDA also takes issue with Hampton Creek’s claim that Just Mayo is cholesterol-free, and points to statements the company makes on its site about heart health, including, “When your heart is healthy, well, we’re happy. You’ll never find cholesterol in our products.”

“Adjacent to this statement is a heart-shaped symbol with a smiling face,” notes the FDA. “Together these statements and heart symbol are an implied health claim that these products can reduce the risk of heart disease due to the absence of cholesterol.”

However, the FDA says, Just Mayo contains too much fat to make such health claims.

The agency instructs Hampton Creek to ensure its products comply with regulations and gave the company 15 days to respond to the letter.

When reached for comment, a Hampton Creek Foods shared a statement from CEO Josh Tetrick.

“We had a good call with the FDA yesterday. They get the import of what we’re doing — and why it matters to our food system,” Tetrick said. “This is larger than a conversation about mayo, as innovation, especially when it has a positive impact, is important to them. We’ll sit down with them shortly, and are excited to talk with them about our approach. They get it much more than folks realize.

And we’re solid on keeping our name. ”

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