Many cities have their entire transit system running on propane or compressed natural gas, there are kits you can buy to convert you car to operate on propane, fork lifts run on propane, inside and outside of warehouses, look around, there are literally thousands of vehicles and pieces of equipment using propane on moving vehicles, it can be done safely, yes you have to use common sense, yes there is a slight risk of fire or explosion, but remember there is 11-40 gallons of highly explosive gasoline near the rear of every car/truck out there.
In Oregon, you cannot dispense gasoline into your personal vehicle, rather it has to be done by a trained and certified attendant, but that does mean that their gas is any more dangerous than the gas in California, or any other state?
It is safe with near non-existence risk to travel with your fridge running.
2011 Dodge Ram 2500 Cummins
2012 Starcraft Autumn Ridge 297 BHS