A Hazmat crew from the Charleston Fire Department raced to a James Island Wal-Mart Thursday afternoon after several people became ill, coughing and complaining of irritated throats.
Firefighters found no dangerous substances in the air, and the store was allowed to re-open, authorities said.
Crews were sent to the store at 1231 Folly Road after people reported the symptoms and officials evacuated the store, according to fire officials.
At 4 p.m. the Hazmat crew entered the building to determine the cause. CARTA buses were also sent to house those affected by the unknown element, according to Capt. Ryan Kunitzer.
Thirteen people were affected, and they were treated on scene, and no one was hospitalized, according to Kunitzer.
After finding no threat, crews allowed the store to re-open around 4:30 p.m. Officials were not able to determine what caused the respiratory irritations.