In periods of uncertainty, it can be comforting to find common ground.

For salad lovers, the current cyclospora outbreak has become an opportunity to throw shade at one of the least fresh leafy green options: iceberg lettuce.

After the U.S. Food and Drug Administration linked the outbreak to iceberg lettuce, more details about the contaminated food supply continue to evolve.

Still, some salad chains have been quick to point out that their lunch would be safe to eat, as the contaminated leaf is flora non grata in their kitchens.

“We do not serve shredded iceberg lettuce,” Chipotle said in a recent all-caps message to users of its app.

Elsewhere on its site, the company specifies that its “super greens” salad mix is ​​made from romaine lettuce, kale, and baby spinach.

“We want to assure our guests that we do not serve iceberg lettuce in our restaurants,” Chopt Creative Salad Company, a Northeast-based chain, said in a notice on its website.

“Sweetgreen does not use iceberg lettuce on our menu,” national chain Sweetgreen said in a similar alert.

On Monday, Just Salad founder and CEO Nick Kenner sent out an email titled “lettuce you can trust,” assuring customers that his company “does not serve iceberg, pre-cut or shredded lettuce.”

The Centers for Disease Control and Prevention has tracked cyclospora cases in 31 states since May 1, including more than 800 confirmed cases and another 1,500 cases under investigation. The cyclospora parasite is transmitted to people who have ingested food or water contaminated with human feces at some point during production, and an infection usually causes severe diarrhea.

The outbreak appears to be dragging down foot traffic, according to location data analytics firm Placer.ai.

On Friday, July 17, visits to Chipotle were down nearly 7% compared to the weekday average at the beginning of the year. Chopt took a 14.3% hit, while Sweetgreen took a modest 1.4% drop, according to the data. Just Salad was not included in the report.

This episode is the latest in a series of bad public relations for iceberg lettuce, which has been criticized for its lack of flavor and nutrition.

“It’s at the bottom of the salad food chain,” Chick-fil-A chief innovation officer David Farmer told Business Insider in 2016. “There’s no nutritional value in iceberg lettuce.”

The farmer removed the ingredient from the chicken chain’s recipes.

Other nutritionists praise iceberg’s ability to stay fresh and crisp where other vegetables wilt, noting that it can be a good source of fiber and hydration.

Either way, avoiding the iceberg is one way to keep your lunch from feeling like a leap of faith.