not sure if that is what is inside, i will check. but like you said, its the last of my worries, as long as the ifre is put out electricals can be replaced. and my truck is so basic that a couple of wires and some breakers and i am good to go.
its the other guys truck that may be an issue if my extinguisher is being used and in that case, well, its not my truck, lol.
I used a different abc a couple of years ago on my truck (fire caused by electrical short) and any bare metal that was exposed rusted within two days. and all the ends of my wires hit by the extinguisher started to corrode and oxidize.