The U.S. Department of Health and Human Services and U.S. Food and Drug Administration (FDA) announced “a series of new measures to phase out all petroleum-based synthetic dyes from the nation’s food supply,” according to a press release.

The FDA said it is fast-tracking the review of calcium phosphate, Galdieria extract blue, gardenia blue, butterfly pea flower extract and other natural alternatives to synthetic food dyes. The agency is also “taking steps to issue guidance and provide regulatory flexibility to industries.”

Which dyes carry risk to human health and at what level is unclear, reported CNN. “Historically, research on food dyes has been underfunded, and the FDA hasn’t thoroughly reviewed food dyes for decades, experts say. Some studies show that dyes can pass through the human body quickly, but others show that they may accumulate over time.”

The Consumer Brands Association, a trade association for the makers of consumer-packaged goods, said that ingredients in the U.S. food supply have been “rigorously studied following an objective science and risk-based evaluation process and have been demonstrated to be safe.”

CNN wrote that for decades, research in animals has shown a potential link between artificial food dyes like red No. 3, red No. 40, blue No. 2 and green No. 3 and an increased risk of cancer or tumors. Other research shows that red No. 40 and yellow No. 5 and No. 6 contain or may be contaminated with known carcinogens.

In January, under the Biden administration, the FDA announced that it had banned the use of red dye No. 3 in ingested drugs, food and beverages.

In 2023, California became the first state to ban red dye No. 3 along with three other food additives that have been linked to disease. It is already banned for food use in Europe, Australia and New Zealand, with a notable exception: maraschino cherries, according to the New York Times.