I’m at the point of deciding it’s not worth it to have one at all. The unlikely odds of a fire starting in my vicinity. The unlikelihood of putting a fire out. The better likelihood of a ‘flying projectile.’ All point in the direction of a do nothing decision.
As long as it's secured properly, the risk of it becoming a projectile is exceptionally small. In a rollover, the G-forces simply aren't anywhere near high enough to dislodge it. Really the only thing that has a chance of dislodging it (other than carelessness in securing it) is a direct head-on allision in excess of 35 mph, or perhaps hitting a parked car at 70+ mph. Even then, the motion profile is only going to be forward of wherever it is. In the case of the driver or passenger seats, it will push your legs forward and up, probably with bruising, but you will have much worse injuries elsewhere.
There are a lot of statistics available on vehicle fires and resulting fatalities, at least on-road:
https://www.usfa.fema.gov/downloads/pdf/statistics/v19i2.pdf
https://www.nfpa.org/education-and-...search/fire-statistical-reports/vehicle-fires
There is a PDF link inside the 2nd article that has some really good detailed information on how fires start based on vehicle type.
I'm not sure if there are any statistics on fatalities or injuries caused by fire extinguishers in particular, but a number of sources claim "13,000" injuries are caused annually by all loose objects:
https://www.gruber-law.com/dangers-of-loose-objects-in-auto-accidents/
Compare the number of loose fire extinguishers to the number of other loose objects in a typical car you might see in a parking lot. I would guess less than 1%, but let's guess 5% to be conservative. This would mean 650 of those 13,000 injuries are caused by loose fire extinguishers, based on these assumptions.
However, now add in the fact that the extinguisher is actually not loose, but instead hard mounted to the point that it can survive all but the absolute worst accident types. While hard to put in numbers, that likely has to bring the number down to the single or low double digits, out of the 345 million people in the US.
Meanwhile, highway fires account for 345 deaths and 1,300 injuries, and even that is just based on a narrow definition. It doesn't seem to account for fatalities caused by fires spreading beyond a vehicle (except to other vehicles).
My point is that you are way more likely to die in a vehicle fire (or more realistically, watch someone else die in a vehicle fire) than you are to be injured by your own extinguisher if it is properly secured.
In addition, it's not just vehicle fires this extinguisher could be used for. How many times have we all seen some idiot flick a smouldering cigarette butt into dry grass, or try and pour gasoline on a lit campfire and instead set the can on fire?
