TNG is Tri-NitroGlycerine, an explosive similar to TNT and others that some people think destroyed the WTC TT

Explosive because the negatively charged Nitro groups can bang into each other setting up most severe repulsion Forces among all 3 of the negatively charged Nitro groupings attached to a Propane HydroCarbon chain of only 3 carbon atoms. The result of these prodigous repulsion Forces is the decomposing of the original molecule into severely hot gases of NO3, NO2, CO2, CH4, and other small molecular weight gaseous molecules.
The same principles can be applied to TNT, C4, and many others including Gasoline, Kerosene, etc.