U.S. District Judge Edward Chen has decided (pdf) that Pepsi must confront allegations that its popular soft drinks contain unhealthy levels of a carcinogen because of their caramel coloring.

The civil case, representing nine class-action lawsuits combined together, claims Pepsi, Diet Pepsi and Pepsi One have levels of the carcinogenic 4-methylimidazole (4-MeI) that exceed what’s allowed under California Proposition 65. That law established a maximum allowable limit of 4-MeI at 29 micrograms a day. Drinks containing the chemical at higher levels have been proven to produce a significant risk of cancer.

The plaintiffs, however, say that Pepsi’s products contain 4-MeI at levels above this safety threshold. They cite a 2014 Consumer Reports study (pdf) that showed the levels of 4-MeI in Pepsi beverages were higher than in other soft drinks tested and, in fact, exceeded more than 29 mcg per can or bottle.

Lead plaintiff Mary Hall claims that, according to Pepsi’s annual reports, the company has known that their drinks breached the safety level. When Proposition 65 was passed in California, Pepsi gave the public the impression it had complied with the new chemical requirement when, in fact, it had not, states the complaint. The soft drink maker intentionally misled the public, said Hall.

Additionally, the lawsuit argues that many consumers drink more than one 12-ounce serving of Pepsi a day, putting them at an even greater risk from unhealthy exposure to the chemical. Judge Chen seemed inclined to agree with that assessment. He wrote:

“In particular, the CAC [Consolidated Amended Complaint] alleges that studies show that consumers who drink soda consume, on average, more than one 12-ounce serving per day. Assuming the facts alleged in the CAC to be true, a plausible inference that, where each serving of the Pepsi beverages contained more than 29 micrograms of 4-MeI, the average daily exposure to a consumer who drinks more than one serving per day exceeds 29 micrograms.”

Chemical 4-MeI is produced as a byproduct in the sodas as a result of the caramel coloring that gives them their distinct look. The chemical has been shown to cause lung tumors in laboratory animals.

–Noel Brinkerhoff, Danny Biederman

To Learn More:

Pepsi Must Defend Against Carcinogen Claims (by Elizabeth Warmerdam, Courthouse News Service)

Caramel Color: The Health Risk That May Be in Your Soda (Consumer Reports)

Pepsi and Coke Remove Harmful Substance from Sports Drinks after Teenager’s Online Campaign (by Noel Brinkerhoff, AllGov)

Stacey Sciortino v. PepsiCo. (U.S. District Court, Northern California) (pdf)