A proposed class action lawsuit was filed Tuesday against McDonald’s, the latest litigation over the E. coli outbreak linked to the fast-food chain’s Quarter Pounders.

The complaint, which needs court certification to proceed as a class action, seeks damages exceeding $5 million for customers across the country who purchased contaminated Quarter Pounders. It alleges that McDonald’s failed to properly disclose that there was a risk of E. coli associated with its menu items. 

“McDonald’s has a responsibility to source its products that it is going to serve other people from safe facilities,” said Roy Willey, the attorney representing the plaintiffs. “In the event that they cannot guarantee that, then they have a responsibility to warn, ‘perhaps this product may be dangerous.’”

No “reasonable consumer” would pay for Quarter Pounders if they knew they were contaminated with a pathogen, Willey added. 

“McDonald’s has a responsibility to step up, reimburse people and do better,” he said.

The lawsuit was filed on behalf of Amanda McCray of Chicago and William Michael Kraft of Davie, Florida — customers who purchased Quarter Pounders earlier this month and then experienced “many of the symptoms associated with E. coli infection,” according to the complaint, which did not specify how ill they became.

McDonald’s declined to comment Wednesday on the lawsuit, which was filed in the Northern District of Illinois. The chain, headquartered in Chicago, has apologized to customers and vowed to regain their trust following the outbreak. 

“The issue appears to be contained to a particular ingredient and geography, and we remain very confident that any contaminated product related to this outbreak has been removed from our supply chain and is out of all McDonald’s restaurants,” McDonald’s North America chief supply chain officer Cesar Piña said in a statement on Sunday, adding that testing of Quarter Pounder beef patties showed no detection of E. coli.

Both McDonald’s and the Centers for Disease Control and Prevention have said that the most likely source of the contamination appears to be slivered onions that came from one supplier, Taylor Farms, and were served on Quarter Pounders. McDonald’s has removed the onions from its restaurants. 

Taylor Farms has said it is working with the CDC and the Food and Drug Administration and has voluntarily recalled the onions.

At least 90 people across 13 states have been sickened with E. coli following meals at McDonald’s, and one person has died, according to the CDC. There have been at least 27 hospitalizations, including a teenager battling kidney failure after developing hemolytic uremic syndrome, a rare and potentially life-threatening complication.

Typical symptoms from E. coli infections include stomach cramps, diarrhea and vomiting, the CDC says. Most people who get sick recover without treatment within a week. Those younger than 5 and older than 65, as well as anyone with a compromised immune system, are at risk of more serious illness. 

The proposed class action lawsuit is at least the third suit related to the E. coli outbreak. A Nebraska woman and a Colorado man each filed injury lawsuits against McDonald’s earlier this month. Both had to go to the emergency room for their illnesses, according to the complaints.

The plaintiffs in Tuesday’s suit allege that McDonald’s breached its duty to provide products that are safe for consumption and alleges the company engaged in “fraudulent, unfair, deceptive, misleading, and/or unlawful conduct stemming from its omissions surrounding the risk of E. coli contamination affecting the Products.”

McDonald’s declined to respond to the suit’s allegations.

Willey said he has received “a lot” of calls from people looking to join the class action suit and he expects the number represented to grow. He said he hopes that the lawsuit will do more than just secure financial compensation for customers.

“The hope would be twofold: one, that McDonald’s does the right thing, comes forward and says, ‘Here’s what happened in full transparency, here’s the money back that you paid,’” the attorney said. “‘And going forward, we are going to look into our suppliers more closely to ensure that they’re following food safety protocols.’”