This work highlights the characterization of epoxy materials by Thermo-Gravimetric Analysis (TGA) and shows that the materials could exhibit considerable weight loss after curing. These weight losses can be characterized by hyphenated methods like Thermo-Gravimetric Analysis Mass Spectrometry (TG-MS) or Thermo-Gravimetric Analysis-Gas Chromatography Mass Spectrometry (TG-GC/MS). Our case study is a set of three epoxies used in an electronic assembly.