Green patina corrosion on Marioff HI-FOG a2000 high-pressure water mist nozzles prevented water release, causing a passenger vessel firefighting system to fail in accommodation spaces.
Consequently, the firefighting system failed to activate in multiple accommodation spaces. Upon expanding the examination, Port State Control Officers determined that the high-pressure water mist nozzles in question were manufactured by Marioff ("a2000" series) as part of the "HI-FOG" system. The accumulation of green patina on the nozzles, a sign of corrosion, rendered them unable to release water after the glass bulb broke.
Source: USCG