Three customers and two employees suffered chemical burns at a Chili's Grill & Bar in Forest City, North Carolina, last Wednesday, Fox News reports. The Foothills Health District said the margaritas had been made with an industrial degreaser. Staff had mistaken it for sugar or salt.

The mix-up began on the Monday before, Fox News reports, citing early findings. An employee got the degreaser from a contracted worker and put it in an unmarked container. The New York Times reports the contractor had been hired to power wash the outside of the building.

On Wednesday, an employee getting the bar ready for lunch found the product, Fox News reports. The worker used it at the margarita station. Three customers who ordered margaritas felt a burn right away and raised concerns with staff, the Times reports. Two workers then tasted it and had the same symptoms.

All five went to local urgent care centers, said Megan Rollins, a spokesperson for the health district, according to the Times. "They had pretty instantaneous symptoms," she said, "so they didn't ingest any more than they did." The Times says it is unclear how bad the burns were.

The health district suspended the restaurant's food permit. The permit was given back on Thursday after checks found the restaurant met all other food safety rules, Fox News reports.

In a statement, Chili's called it "an isolated incident" and said it acted right away to support those affected, Fox News reports. Fox notes that the company's statement spoke of injuries to two guests. The health district said three customers were burned.

"This incident highlights the importance of proper chemical labeling, storage, and handling in food service establishments," said Jason Masters, the health director of the district, according to Fox News. The district reminded all food businesses in the state to label chemicals and keep them away from food.