Torsiello said he was not authorized to release the man's name.
Two cats were rescued from the basement, he said.
Based on his initial investigation, Deputy State Fire Marshal James Michael Woods said it appeared the man was working on a car in the garage when some gasoline spilled, emitting fumes that were ignited by an undetermined source.
That appears to have caused a "low-order" explosion, which pushed the bottom of the garage out more than a foot and sent debris flying more than 60 feet, Woods said.
The fire didn't spread to the house, where a female resident was at the time, he said.
"We pretty much just had a contained fireball," Woods said.
The explosion damaged the interior of the garage and its contents, including two cars, a pickup truck, cabinets and tools.
Neighbor Charles Young said he was watching television and didn't know there was an explosion until he heard Banzhoff banging on the door.
"He got burned real bad," said Young, who said Banzhoff appeared to have burns on both hands, the side of his face and his shoulder.
He said Banzhoff restores cars.
Washington County Hospital spokeswoman Beth Kirkpatrick confirmed the hospital had a patient named Darryl Banzhoff but said he had been transferred to another facility.
A nursing supervisor at the Johns Hopkins Bayview Medical Center in Baltimore said late Wednesday that the hospital was expecting a patient by that name but it would be several hours before a condition would be available.