A woman who drank sweet tea laced with a highly toxic industrial cleaning solution at a Utah restaurant has suffered deep, ulcerated burns in her upper esophagus.

Family attorney Paxton Guymon said in a statement Friday that 67-year-old Jan Harding remains in critical condition. She also has severe mouth burns.

Guymon says Harding's family is very disappointed with the news. He says the internal burns are deeper and more widespread than they hoped.

Harding has been in critical condition since Sunday, when she drank the tea at Dickey's Barbecue Pit in South Jordan.

Guymon says investigators and the restaurant manager have told the Hardings that a worker mistook the cleaning product for sugar and accidentally mixed large quantities of it into the iced-tea dispenser. The product was meant for degreasing deep fryers and contained the odorless chemical lye.