Benjamin Damian, 44, was listed in critical condition at the Joseph M. Still Burn Center at Doctors Hospital in Augusta hours after the midday accident, hospital spokeswoman Olena Scarboro said.
Damian and fellow worker Amando Serritos were dismantling the tank with a torch when the container blew up, Garden City Fire Chief James Crosby said.
The tank, roughly 8 feet wide and 20 feet long, appeared to contain oil residue when firefighters arrived at the Tremont Road facility, Crosby said.
Both Damian and Serritos were initially taken by ambulance to Memorial University Medical Center.
Serritos, age not available, was treated in Savannah and released, while Damian was transferred to the burn center in Augusta, Memorial spokesman Michael Notrica said.