An ingredient Impossible Foods says makes its plant-based burgers “meaty” should have undergone more testing by the Food and Drug Administration, the Center for Food Safety contends in a brief filed in federal appeals court in California.

“FDA applied an incorrect, lower safety standard than required by its own color additive regulations when it approved soy leghemoglobin as a color additive,” thus violating the Federal Food, Drug and Cosmetic Act, CFS said in its filing last week. The group has sued FDA, but Impossible Foods has intervened.

Impossible produces the protein, found naturally in soy roots, through fermentation of a genetically modified strain of yeast. In a brief filed in the case last year, Impossible contended the court has no jurisdiction over the Center’s petition because it “is grounded purely on generalized, speculative, and unsubstantiated concerns.” It also said sufficient testing had been done.

Interested in more coverage and insights? Receive a free month of Agri-Pulse West.

CFS, however, says “the novelty of soy leghemoglobin, and the large amount consumers are exposed to, place it in FDA’s ‘highest probable risk to human health’ category, which according to FDA’s own authoritative guidelines should have triggered extensive toxicity testing, including subchronic, chronic, carcinogenicity, and reproductive testing.”

The case is scheduled for oral argument in April.

For more news, go to