It's the temperature of an electric spark that ignites stuff. The charcoal in gunpowder is such a good conductor of electicity that the current going through it won't make it hot enough to ignite, usless you have currents way higher than the microamps, nay, nanoamps of current seen in a typical static discharge.
Anyway, having the charge wrapped in aluminum foil makes it safer still. One of the reasons Goex and others have used steel cans for their product was concern for static. Now even Goex is converting to plastic cans, perhaps the plastic is an electrical conductive plastic formula like the electrically conductive plastic used to package mosfets and other static sensitive electronic components.
The "g" in FFg, FFFg etc. stands for glazed. The powder granules are glazed in a coating of graphite, which is electically conductive and forms a mini Faraday cage around each granule of powder.