Titanium dioxide is set to be banned in the European Union in August, the complaint noted. The ban comes after a food safety regulator there had deemed the chemical compound unsafe because of “genotoxicity,” or the ability to change DNA.

The European Food Safety Authority announced in May 2021 that titanium dioxide “can no longer be considered safe as a food additive.” The authority said that it “could not exclude genotoxicity concerns after consumption of titanium dioxide particles,” adding, “After oral ingestion, the absorption of titanium dioxide particles is low, however they can accumulate in the body.”

The lawsuit from Thames said that people who consume Mars’s products “are at heightened risk of a host of health effects for which they were unaware stemming from genotoxicity—the ability of a chemical substance to change DNA.”

In a statement to news outlets, a Mars spokesperson said the company does not comment on pending litigation, but that Mars’s use of titanium dioxide is in compliance with regulations under the U.S. Food and Drug Administration (FDA).

Mars had publicly stated in February 2016 that it would phase out artificial colors from its food products over the following five years, attorneys for Thames noted in the complaint.

The lawsuit alleged that Mars “has long known of the health problems posed by TiO2.”

In October 2016, Mars confirmed that titanium dioxide was among the artificial colors being removed, according to the Center for Food Safety, citing an email from Mars.

According to the lawsuit, the reason for eliminating titanium dioxide is “simple.”

“TiO2—which is used in paints, coatings, adhesives, plastics, printing inks, and roofing materials—has demonstrated an ability to pass through biological membranes, circulate through the body, and enter cells,” the complaint reads.

“Research shows that the effects are serious, including DNA and chromosomal damage, organ damage, inflammation, brain damage, genital malformations, lesions in the liver and kidneys, and cell neurosis.”