The primary fuel used in lighters is typically butane or a mixture of butane and propane. This fuel is chosen for its ease of ignition and portability, making it ideal for small, portable devices. According to the U.S. Fire Administration, butane lighters are the most common type, accounting for approximately 80% of all lighters in use. The fuel's low flash point allows for quick and easy ignition, which is crucial for a lighter's intended purpose. Additionally, butane is odorless and colorless, which enhances its suitability for use in lighters.