In August 2006, the International Association of Classification Societies (IACS) released a document titled the "Unified Requirements for Polar Ships" which standardized global ice classification specifications.
The IACS established seven different Polar classes, with each level representing changes with respect to the operational capability and strength of steel ships.
|Polar class||Ice description (based on WMO Sea Ice Nomenclature)|
|PC 1||Year-round operation in all Polar waters|
|PC 2||Year-round operation in moderate multi-year ice conditions|
|PC 3||Year-round operation in second-year ice which may include multiyear ice inclusions.|
|PC 4||Year-round operation in thick first-year ice which may include old ice inclusions|
|PC 5||Year-round operation in medium first-year ice which may include old ice inclusions|
|PC 6||Summer/autumn operation in medium first-year ice which may include old ice inclusions|
|PC 7||Summer/autumn operation in thin first-year ice which may include old ice inclusions|
- "Guidelines for Ships Operating in Arctic Ice-covered Waters" (pdf). International Association of Classification Societies. Retrieved 2013-02-18.