Avgrening

Corrosion class

C1

C2

C3

C4

C5

CX

Environmental corrosion

Very low

Low

Average

High

Very high

Extreme

Examples of environments

Indoors

Heated areas with arid atmosphere and insignificant quantities of pollutant, e.g. offices, shops, schools and hotels.

Non-heated areas with fluctuating levels of temperature and humidity. Few instances of condensation and low levels of airborne pollution, e.g. sports halls and warehouses.

Average levels of humidity and some airborne pollution resulting from production processes, e.g. breweries, dairies, laundries.

High humidity and considerable airborne pollution as the result of production processes, e.g. chemical plants, swimming pools and dockyards.

Buildings with almost permanent condensation and with high pollution

Industrial buildings with extreme humidity and aggressive atmosphere.

Outdoors

Atmospheres with low levels of airborne pollution. Rural areas.

Atmospheres containing some salt or average levels of air-borne pollution. Urban and light industrial areas. Areas affected by coastal conditions.

Atmospheres with average salt content or discernible levels of airborne pollution. Industrial and coastal areas.

Industrial areas with high humidity and aggressive atmosphere, and coastal areas with high salinity

Offshore areas with high salinity, industrial areas with extreme humidity, and aggressive atmospheres, sub-tropical or tropical atmospheres.

Wibe Group designation

Exceeds requirements. Extremely high durability.

Recommended very high durability ( >20 years)

Possible alternative. High durability (10-20 years)

Electro-galvanized (EG)

Pre-galvanized (PG)

Zinc+ (Z+)

Hot-dip galvanized (HDG)

Zinkpox (ZP)

Stainless steel AISI 304L(SS304)

Stainless steel AISI 316L (SS316)

Glass Fibre Reinforced Polymer (FRP/GRP)