Emergency crews were called to a high voltage UPS battery fire overnight at a Beresfield business.
On a arrived staff on site quickly directed crews to a computer room filled with toxic smoke from the battery.
Firefighters quickly don on their breathing apparatus equipment and begun working on the night voltage battery.
NSW ambulance was called to the scene to treat several Fire Fighters who received static electricity shocks from the co2 fire extinguishers.
The fire fighters were accessed by NSW Ambulance and were given an ECG test before returning to duties.