The Zippo lighter uses a specialized fuel known as Zippo lighter fluid. This fuel is a highly volatile, flammable liquid that is designed to ignite easily and provide a consistent flame for lighting cigarettes, cigars, and other items. The primary ingredient in Zippo lighter fluid is naphtha, which is a petroleum distillate. Naphtha has a low flash point, meaning it can ignite at relatively low temperatures, making it ideal for use in lighters like the Zippo.

The choice of naphtha as the main component in Zippo lighter fluid is due to its unique properties. Naphtha has a high volatility, which allows it to evaporate quickly and create a rich vapor cloud that can be easily ignited. This is crucial for the Zippo lighter's unique design, which relies on a windproof flame to ensure a consistent burn. The high volatility also means that the lighter fluid can be stored for extended periods without evaporating significantly, which is beneficial for users who may not use their lighter frequently.

According to a study published in the Journal of Analytical and Applied Pyrolysis, naphtha has a flash point of approximately -45°C (-49°F), which is well below the temperatures typically encountered in everyday use. This low flash point contributes to the ease of ignition and the reliability of the Zippo lighter. Additionally, the study notes that naphtha has a relatively low boiling point, which allows it to be easily vaporized and ignited by the spark from the lighter's flint wheel.

The use of naphtha in Zippo lighter fluid is also supported by its availability and cost-effectiveness. Naphtha is a byproduct of the petroleum refining process, making it readily available and relatively inexpensive. This has allowed Zippo to maintain a competitive edge in the market by offering a high-quality lighter at an affordable price point.

In conclusion, the Zippo lighter uses naphtha as its primary fuel due to its high volatility, low flash point, and cost-effectiveness. These properties make naphtha an ideal choice for a lighter that requires a consistent and reliable flame, as is the case with the Zippo lighter.