"You can extinguish fire with this."
"It's an empty extinguisher. I must fill it with the extinguishant before I can use it."
The extinguisher is an event item in Resident Evil CODE: Veronica and Resident Evil CODE: Veronica X.
It is also used to put out the fire at the Antarctic Base to obtain the Magnum in the weapon storage bay.
It is found when a large metal shutter that is close to the anatomy room is opened. When emptied, it can be refilled at the Antarctic Base.