Analyses of electrical fire causes and derived dioxins

Abstract

Identification of molten marks is critical for the electrical fire investigation However a lack of public acceptable identification methods has challenged the credibility of investigators The current practiced metallographic method came with the risk of misjudgment for subjective assessment and nonspecific characteristics for primary molten marks (PMMs) or secondary molten marks (SMMs) This work focuses on the development of a nondestructive reproducible and objective molten mark identification method The differences of chemical structure between PMMs and SMMs is distinguished by the combined methods including X-ray diffraction (XRD) and X-ray absorption near edge structure (XANES) which is verified as a reliable method X-ray fluorescence spectrometer (XRF) is also used for on-site identification The analysis of the XRF is shown the corresponding relevance with that of the XRD and XANES data which proves the feasibility of this alternative method To realize the kinetics and derived toxic species from the burning of PVC wire jacket the weight lost data are determined by thermogravimetric analysis It is clear that by GC/MS dioxins are formed at 827-1083 K Toxic dioxin emissions during the PVC wire burning may also have a negative impact to the fire fighters The better understanding of the dioxin formation during electrical fires may reduce the risk of the fire fighters and victims to a great extent

Date of Award	2018 Aug 30
Original language	English
Supervisor	Hong-Paul Wang (Supervisor)