Gas forklifts run on natural gas. They can be refueled quickly and easily, but they require storage for the fuel, and as with diesel, the fuel can become expensive. Gas forklifts use canisters of fuel, similar to a gas cooker, but much larger of course, which are switched out to refuel, and then the empty ones are refilled. Therefore, even though gas forklifts are less expensive to purchase initially, the cost of fuel quickly adds up, making them more expensive per use than electric. Gas powered forklifts are ideally suited to outdoor use, however can be used indoors in well ventilated areas for short periods, as the emissions they produce are dangerous if inhaled in an enclosed area. These trucks can generally handle rugged or rough terrain and handle larger loads, some up to 10,000 kilos, and can be used for minor pushing or towing as well.