LP Gas-fired water heaters? Aren't they dangerous?

Gas-fired water heaters are no more dangerous than your LPG stove right in your kitchen.  Using gas to heat water is nothing new.  Most commercial systems, hotels and motels, the food courts in the malls, canteens in your office building, restaurants using dish washers, and gyms use LPG storage water heaters.  The Operating cost of an LPG water heater is roughly half of an equivalent electric water heater.  That's why it is popular for commercial use requiring centralized water heating systems.