This part of IEC 61249 gives requirements for properties of phenolic cellulose paper, reinforced copper-clad laminated sheets of high electrical grade in thicknesses of 0,8 mm to 3,2 mm. This standard covers materials with different requirements on flammability and are designated according to the following: Material 61249-2-2-1; Material 61249-2-2-2; and Material 61249-2-2-3.