In addition to being cleaner than gasoline, GM also touts the safety benefits of using hydrogen as fuel. The main benefits are that it burns at a higher temperature than gasoline and, more importantly, it's lighter than air, so if leaks out it rises up and away from the vehicle rather pooling underneath it like gasoline.
The Equinox Fuel Cell's hydrogen tanks are made from an impermeable membrane wrapped in about an inch of carbon fiber. In tests, they've proved nearly impossible to puncture, GM claims. If they are punctured - to test the "worst case scenario," technicians shot a hole in one with a gun - the gas tank stays together while the hydrogen gas leaks out.
The vehicles have also been put through a variety of crash tests including several not required by the government but designed specifically to test this vehicles' potential weak points, GM says.
In the event of a crash, as detected by various on-board sensors, the flow of electricity and hydrogen through the vehicle would be automatically cut off, GM says.