Good question, keep in mind that the mount I built its completely custom, this "arrangement" is a friction fit and holds the can very tight. The insurance is the chain that holds the can from moving vertical in the mount as shown in the pic. I don't have any solid evidence to the fact other than several hundred miles of highway driving with it at 65mph. As far as bumpy trail driving goes, the chain would keep it attached to the vehicle. Years of flying and working on airplanes with very flammable substances has led me to believe that if you keep the fuel away from ignition, you will mitigate some level of hazards. This of course doesn't take into account someone slamming into the back of your vehicle.... If that is a concern, please don't mount a hazmat container externally to the rear of your vehicle. BUT if looking "cool" and not running out of gas is your thing, by all means, fab it up gents!!!