Analysis of a major fire incident at a home furnishings warehouse led to the conclusion that extended exposure of electrical insulating materials composing a lampholder in a fluorescent lamp were the initial items ignited. It was thought that these items, composed of thermoset polymers, were ignition-resistant materials. However, analysis showed that thermally induced degradation caused the material to degrade into an easily ignited, char-like residue. The parent polymer, highly cross-linked urea formaldehyde, had been initially cast into the lampholder configuration To prevent high voltage conditions and arcing.
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