Anticipated lifetime in years until 5% dark brown rust.
C1: Very Low (Internal buildings with clean atmospheres) 100 years +
C2: Low (Low level of pollution, mostly rural areas) 100 years +
C3: Medium (Urban and industrial atmospheres, moderate sulphur dioxide pollution, coastal areas with with low salinity) 93 years
C4: High (Industrial areas and coastal areas with moderate salinity) 47 years
C5: Very High (Industrial areas with high humidity and aggressive atmosphere, coastal and offshore areas with high salinity) 25 years
CX: Extreme (Extreme industrial areas, coastal and offshore areas with contact with salt spray) < 10 years