A Safe Fuel Propane vehicle tanks are constructed from carbon steel under a code developed by the American Society of Mechanical Engineers. A propane tank is 20 times more puncture resistant than a typical gasoline, methanol or ethanol tank. New propane cylinders are manufactured with a device that shuts off the filling process when the tank reaches 80 percent of its liquid capacity. This allows for changes in fuel volume caused by temperature variations without any release of gas from the tank. Propane engine fuel systems are fitted with safety devices and shut-off valves that function automatically if the fuel line ruptures.
Propane has the lowest flammability range of any alternative fuel.
Propane leaks are easily detected because an odorant with a scent similar to rotten eggs is added as a safety measure. Propane is a nontoxic, nonpoisonous fuel that doesn't contaminate aquifers or soil. Unlike gasoline and alcohol fuels, propane can't be ingested because it is stored in a closed container under pressure. It vaporizes internally when released from its container. Propane with air won't ignite unless the source of ignition reaches at least 940 degrees Fahrenheit.