The "Fuel Safe" is FIA approved and made from high impact rubber and also has a fuel bladder. The Jazz fuel cell a "seamless cross-linked polyethylene outer shell" - which is proberly more forgiving than an alloy tank in an accident.
Both tanks have "Fuel Foam" which - and I quote "Stops sloshing, great for holding down pumps, hoses or pickups. Can be cut down to fit. important purpose or function of Fuel Cell foam is to stop a flame front from advancing, therefore helping to eliminate the possibility of an explosion. When a racing car changes direction quickly, fuel foam helps reduce surge or fuel "slosh" inside the fuel cell, creating a baffling affect. Upon receiving a sudden impact, the fuel foam inside the fuel cell helps dissipate and absorb a great amount of energy of the impact, thus reducing the risk of fuel cell rupture. The fuel foam will expand upon contact with fuel. To properly function, the fuel cell should have no more than 75% of the area filled with fuel foam. Foam should be changed every couple of years as additives in most fuels will cause the fuel foam to deteriorate over time. Check your fuel filters and other system components for signs of deterioration."