For corrosion category C5 conditions (very high corrosion activity) according to ISO 12944, the most thorough surface preparation is required, as these conditions involve extreme loads (industrial areas with high humidity and aggressive environments or coastal/marine zones with high salt content). The minimum preparation grade is Sa 2.5 according to ISO 8501.
Nominal dry film thickness is the thickness of the dried coating, specified for each layer or the entire coating system.
Considering the aggressiveness of these conditions, the standard does not permit the use of alkyd coatings.