This part of IEC 61249 gives requirements for properties of phenolic cellulose paper reinforced copper-clad laminated sheets, economic grade in thicknesses of 0,8 mm up to 3,2 mm. This standard covers materials with different requirements on flammability, designated according to the following: Material 61249-2-1-1: general purpose grade, requirement on flammability not specified, and Material 61249-2-1-2: materials of defined flammability (vertical burning test). These grades of material cover one of two flammability requirements, designated at FV0 or FV1.