ENVIRONMENT
For applications where the prepainted products are submitted to the influence of exterior atmospheres, the end user has to consider the environments for successful usage and correct product application for its long-term service. Here are some examples and descriptions of environments:
RURAL
ENVIRONMENT
Rural areas are an environment with low corrosion impact. Typical coatings of corrosion resistance category RC2 according to EN10169 provide adequate and effective functionality of buildings in this environment. There are also other coatings available with a higher corrosion resistance category which prolong the lifetime and durability of coated objects.
URBAN
AREA
Urban areas are an environment with moderate corrosivity. Typical coatings for buildings in an urban area have corrosion resistance category RC3 according to EN10169 which provides adequate and effective functionality of buildings. Available are also coatings with a higher corrosion resistance category which prolong the lifetime and durability of coated objects.
INDUSTRIAL
AREA
Industrial areas are an environment with industrial pollution that negatively influences the durability of the coating. The extent of coating deterioration is related to the content of SO2 in the atmosphere. For buildings in an industrial environment it is necessary to specify a coating with a corrosion resistance category RC3, RC4 or RC5 according to EN10169 depending on SO2 levels. Coatings with lower corrosion resistance are not recommended, as the functionality and appearance of coatings can be negatively affected and the lifetime of buildings shortened.
MARINE
AREA
Coastal and at the same time industrial areas are considered as the most critical and severe environment for prepainted steel. This is an environment with combined industrial pollution together with humidity and salts which pose a threat to the durability of the coating. For the buildings in a coastal and industrial area, a coating with a corrosion resistance category RC5 according to EN10169 should be required and applied. Coatings with lower corrosion resistance are not recommended, as the lifetime, functionality and appearance of coatings can be negatively affected.
COASTAL
AREA
Coastal areas are an environment with presence of humidity and salts from the sea that have negative impact on the durability of coatings and the lifetime of the buildings. For buildings to be located in coastal area it is necessary to specify coatings with a corrosion resistance category RC3, RC4 or RC5 according to EN10169, depending on the vicinity to the seashore and overall salinity of the air. Coatings with lower corrosion resistance are not recommended, as the functionality and appearance of coatings can be negatively affected and the lifetime of buildings shortened.
RELATIONSHIP BETWEEN CORROSION RESISTANCE CATEGORIES, CORROSIVITY CATEGORIES AND TYPES OF ATMOSPHERE - TYPICAL ENVIRONMENTS IN A MODERATE CLIMATE (SEE ALSO EN ISO 12944-2)
|
Corrosion resistance category |
Corrosivity |
Rural area |
Urban area |
Industrial area |
Marine area |
Polution |
Coastal area |
|---|---|---|---|---|---|---|---|
|
RC 1 |
C1 - very low |
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RC 2 |
C2 - low |
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RC 3 |
C3 - medium |
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Low SO2 |
Low salinity |
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RC 4 |
C4 - high |
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Moderate SO2 |
Moderate salinity |
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RC 5 |
C5-I - very high |
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High SO2 |
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C5-M - very high |
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High salinity |
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High salinity |
Description of environmental corrosivity (EN ISO 12944-2:2017)
|
Corrosivity class |
Environmental corrosivity |
Environment example – exterior |
Appropriate coating system |
|---|---|---|---|
|
C1 |
Very low - All |
- |
All |
|
C2 |
Low |
Atmospheres with low levels of air pollutants, mainly rural environment. |
All |
|
C3 |
Moderate |
Urban and industry atmospheres with moderate levels of air pollution by sulphur dioxide, coastal atmospheres with a low degree of salinity. |
All |
|
C4 |
High |
Industrial atmospheres and coastal atmospheres with a moderate degree of salinity. |
PUR 50; HDP 50; HBP 50 |
|
C5-I |
Very high (Industrial) |
Industrial environment with high humidity and aggressive atmospheres. |
* After prior agreement |
|
C5-M |
Very high (Maritime) |
Coastal and offshore environment with high levels of salinity. |
* After prior agreement |
Information!
Applicable zone of hot dip galvanized sheets with organic coatings should be at least 3km inland from the coast.
INTERIOR
Categories of corrosivity
According to the corrosivity of the atmosphere inside a building the interior atmospheres may be classified into different categories.
The following corrosion conditions should be taken into account:
- The aggressivity of the atmosphere including (when applicable) the conditions for cleaning the interior walls of the building, e.g. frequency of cleaning, aggressivity of the cleaning solutions and use of disinfecting treatments,
- The risk of condensation, i.e. risk of occasional condensation, frequent condensation, permanent condensation.
Non-agressive environment
Very low aggressivity to the coating specified according to atmosphere category A1, as defined in EN10169. The atmosphere has no chemical aggressivity and the periodicity of cleaning operations with neutral cleaning products is not more than once a month.
Examples: offices, schools, residential (except kitchens and bathrooms), dry storage.
Low-agressive environment
Low aggressivity to the coating specified according to atmosphere category A2, as defined in EN10169. The atmosphere has no chemical aggressivity and the periodicity of cleaning operations with neutral cleaning products is not more than once a week.
Examples: sports halls, cinemas, theatres, cold stores, supermarkets.
Medium-agressive environment
Moderate aggressivity to the coating specified according to atmosphere category A3, as defined in EN10169. The atmosphere has low chemical aggressivity and periodicity of cleaning operations with cleaning products of pH between 5 and 9 is not more than once a week.
Examples: kitchens and bathrooms, food processing, industrial buildings with dry processes.
Agressive environment
High aggressivity to the coating specified according to atmosphere category A4, as defined in EN10169. The atmosphere has chemical aggressivity or risk of moulds and periodicity of cleaning operations with cleaning products of pH between 5 and 9 is not more than once per day.
Examples: swimming pools, factory buildings with wet industrial processes (e.g. breweries, wine cellars).
Very agressive environment
Very high aggressivity to the coating specified according to atmosphere category A5, as defined in EN10169. The atmosphere has high chemical aggressivity or high risk of moulds and periodicity of cleaning operations with cleaning products of pH between 5 and 9 is minimum once per day. This must be agreed at the time of inquiry and order.
Examples: Mushroom culture, livestock buildings, dairies, paper mills, seafood processing.
Information!
Standard material is produced for A1 and A2, non and low-agressive ambience; higher upon request.