A Comparative Study of the Fire Performance of Halogenated and Non-Halogenated Materials for Cable Applications. Part I Tests on Materials and Insulated Wires

Abstract

This paper, the first of a series of three, describes the results of an extensive study of the mechanical physical, electrical and fire properties of polymeric materials, both halogenated and non-halogenated, intended for cable applications. The objective of this study was to provide, by means of generally recognized standard tests, data, which should make possible a dispassionate fire hazard analysis of the relative merits of materials. Excellent materials were found with different chemical compositions. The results indicate the following: (1) Materials can be suitable for wire and cable applications irrespective of their chemical composition. (2) Halogen-containing materials, as a group, tend to outperform non-halogen materials in terms of the major fire properties: •Heat release •Ignitability •Flammability (3)Most commercial materials tend to have adequate mechanical and physical properties, but halogenated materials are, as a rule, slightly more satisfactory. (4)Compared to fire retarded non-halogenated materials, halogen-containing materials tend to have better performance in terms of some of the more important electrical properties, particularly dielectric breakdown voltage. (5)The resistance to ageing of non-halogenated materials is somewhat suspect, particularly with respect to attack by oils. (6)The smoke obscuration per unit mass of non-halogenated (polyolefin-based) materials is superior to that of vinyl-based materials, but differences are significantly reduced when considering the expected smoke obscuration in actual full-scale fires, due to the overall lower tendency of halogenated materials to burn; the smoke obscuration resulting from fluorinated materials is also low. (7)Smoke corrosivity is the single property where non-halogenated materials clearly outperform halogenated materials.