Depending on the regulator valve of the barbeque, it can be either propane or butane. Propane seems to be the most common these days.
Source: http://www.infomania.co.uk/archives/234
Propane
A gas regulator helps to maintain a steady flow of gas. A propane tank is an example of an item with a gas regulator. One opens up the tank to allow the right amount of gas to flow to the BBQ.
Ethane, methane, propane, butane and natural gas are the most common.
There is only one type of propane that can be used for your BBQ. If you go to any store that sells propane for BBQs you will be able to purchase a tank of propane. However since this is the first time you will be connecting your BBQ to a propane tank you have to make sure that you have the right fittings and hose to connect to the tank.
Natural gas or electric=stoves Propane or charcoal=BBQ.
A gas BBQ grill is easier to use, and is more convenient, but a charcoal grill will give you a smoky flavor, which cannot be achieved by using a gas BBQ. Gas BBQs are also safer than charcoal grills.
Beaker Bottle Vessel
The best person to talk to about reviews on a gas BBQ is the people who sell the units. They can give you all the spec's on there BBQ's and may also have testimonials from people who have bought BBQ's from them. Another good way is to talk with people who love to BBQ. and have experience with indoor units.
Propane, LPG, or natural gas (methane)
A gas pump is used to move the fuel from the gas tank into the engine. Every gas station, from Esso, Shell, Petro Canada to Ultramar have something like this.
Autozone and Advance auto both have gas tank repair kits that can be used to patch the tank.
Yes considering BBQ does create carcinogens it can be considered carcinogenic