We used flamethrowers in general up to vietnam, although they’ve never been really widespread.
Incidents of flamethrower explosions in the real world were incredibly rare.
Not sure how binary explosives got related into it, but flamethrowers do not work on the same concept. Flamethrower fuel isnt inert until mixed, it just requires a perfect storm of circumstances to be punctured in such a way that the gasses can mix in the environment and basically generate an improvised fuel/air bomb.
And all that being said, you cannot put flamethrowers in a game (or movie) without giving them a chance to explode. Pretty sure that’s at least a class II misdemeanor.