SALT LAKE CITY (AP) -- An industrial cleaning solution that ended up in tea that a woman drank at a Utah restaurant was unintentionally mixed into a bag of sugar a month earlier, authorities said Friday.
South Jordan Cpl. Sam Winkler said a former employee told authorities the mixing of the cleaning product into the sugar bag happened July 5.
On Sunday, a worker took large quantities of the substance thought to be sugar and poured it into the iced-tea dispenser, he said.
A 67-year-old customer, Jan Harding, drank the tea that day at Dickey's Barbecue in South Jordan, severely burning her esophagus and mouth. She remained hospitalized Friday in critical condition.
The cleaning product is meant for degreasing deep fryers and contains the odorless chemical lye, the active ingredient in drain cleaners.
Winkler said police are waiting to see what happens with Harding's condition before moving forward with any arrests or charges.
KSTU-TV in Salt Lake City first reported what led to the mix-up.
Dickey's Barbecue Restaurants Inc. said in a statement late Friday that it was an isolated incident and nothing like it had happened in the 73 years the Dallas-based chain has operated.
"There is nothing more important to us than the trust and safety of our guests," the statement said, adding that the franchise owner, John Thomson, was deeply saddened and is cooperating with authorities.
His restaurant is one of 400 Dickey's around the country. South Jordan is a suburb of 60,000 about 15 miles south of Salt Lake City.
Doctors have determined Harding has deep, ulcerated burns in her upper esophagus, family attorney Paxton Guymon said. They found the internal damage Thursday while doing an endoscopy, which involves inserting a tube with a light and camera into the digestive tract.
"The news was very disappointing and disheartening for the family," Guymon said in a statement. "The burns were deeper and more extensive than we had hoped."
Harding and her husband had just arrived at the restaurant for lunch with friends when she filled her cup with sweet tea from a self-serve beverage station. She took one sip before spitting it out and exclaiming to her husband: "I think I just drank acid."
Police have determined Harding is the only victim, Winkler said. It appears she was the first to drink the tea that day, and Dickey's employees disposed of it after she was burned, he said.
The establishment remains open after county health officials inspected it and found all chemicals properly labeled and separated from food items.