Propane Autogas is nontoxic, has a lower flammability range than conventional gasoline, and odorized for easy detection. Their Containers are equipped with safety devices, including pressure-relief valves, shut-off valves that detect fuel line ruptures (due to collisions on the road), and overfill protection. As well as being constructed from carbon steel and are 20 times more puncture-resistant than conventional gasoline and diesel tanks.