Mentioned by the Computer system in the Rockfort Island Military Training Facility in Resident Evil CODE:Veronica. Not much is known on how it classified either. However, logically, it is less serious than a Biohazard Level 4 Contamination. To stop a level 3 contamination, the section is closed off after forty seconds of the alarm being triggered. Poisonous gas fills the room in order to kill any living organism whether infected or not. The poisonous gas is then automatically vented out of the room and the section can be re-entered after the all-clear is given.