Forensic Analysis and Fractography of Glass Candle Containers

Candle containers are generally comprised of soda-lime glass which is strong and chemically stable but also brittle and a poor thermal conductor. When candles fail, the container operates at an intersection of thermal stresses and heat transfer that result in container fractures and fire patterns that are specific to the failure mode of the candle. Understanding these interactions is critical to candle forensics, as the container forms the physical barrier that prevents inadvertent ignition of other items.

In this talk, the author reviews candle “barrier technology” relative to ASTM standards including ASTM F2601 and recent proposed changes to ASTM F2179. Testing conducted by S-E-A to induce various candle failure modes will be compared, relative to the resulting fractures of the container. These modes include flashover, wick migration, secondary ignition, and fire outside the container. These lab-induced container fractures are also compared to existing literature and fractographic references of glass containers and products. Case studies will be examined to connect the lab testing to real-world incidents.