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 (see 7.3.1); Material 61249-2-1-2: materials of defined flammability (vertical burning test) (see 7.3.2). These grades of material cover one of two flammability requirements, designated as FV0 or FV1 and shown in Table 8. Some property requirements may have several classes of performance. The class desired should be specified on the purchase order, otherwise the default class of material may be supplied.