IEC 60332-3-25:2000 Specifies method of test for the assessment of vertical flame spread of vertically-mounted bunched wires or cables, electrical or optical, under defined conditions. The test is intended for type approval testing. The requirements for the selection of cables for testing are given. The flame spread is measured as the extent of damage of the cable sample. This procedure may be used to demonstrate the cable's ability to limit flame spread. Covers category D and relates only to small cables of overall diameter 12 mm or smaller installed on the test ladder to achieve a nominal total volume of non-metallic material of 0,5 l/m of test sample. The flame application time is 20 min. The method of mounting uses the front of the standard ladder in touching formation only. The category is intended for use with small cables where very low volumes of non-metallic material are required to be evaluated. A recommended performance requirement is also given. It has the status of a horizontal standard in accordance with IEC Guide 104.