Forklift gas is a form of propane mixed with other compounds to varying degrees. The most common form of forklift gas is Liquified Petroleum Gas (LPG), which, in the US and Canada, is largely composed of propane. As of 2011, in European countries, it can have up to 15% of other components such as butane, sulfur, and propylene. LPG and pure propane fuel are derived from petroleum and natural gas refining processes and are the most common category of fuels for heavy duty types of forklifts.
Gas forklift machinery is less expensive to purchase than its electric counterparts, as it doesn't require the durable, rechargeable batteries upon which an electric forklift depends. The cost between these two major types of forklifts can balance out depending on usage levels, as using a forklift that runs on gas will cost more to operate in the long run than an electric model. An electric forklift will also only run for six to seven hours, and then require up to 16 hours of recharging, which can cause production bottlenecks. Forklifts running on LPG have no such limitations as long as the fuel supply is plentiful.
One of the downsides to burning forklift gas is that it produces toxic exhaust byproducts, so these machines are designed for primarily outdoor operation. An electric forklift can be operated indoors with zero emissions. A propane gas-powered forklift, or one that runs on gasoline or diesel fuel, will emit carbon monoxide, nitrogen oxide, and more, though propane is a slightly cleaner burning fuel than gasoline or diesel.
Despite increased long-term costs and the pollution factor, forklifts based on LPG fuels are the most common in industry. This is due in part to the portability and safety of storing the propane fuel tanks on site versus gasoline or diesel. A machine using forklift gas also has much more power than an electric counterpart and can lift up to 52 tons, where the maximum lift capacity for an electric forklift is in the range of five to seven tons.
Of all the types of forklifts available, those that operate on forklift gas are leaders in every application where power and long-term operation demands are high. Their superior performance tends to outweigh the fact that they can have negative long-term health effects on the operators who are exposed to fumes on a full-time basis. Other workers who must be nearby them on a constant basis, whether inside or outside, are also exposed to the detrimental emissions produced by forklift gas.