How many gases are classified as LPG?

Liquefied Petroleum Gas (LPG) primarily consists of propane and butane, which are both gases at room temperature but can be easily liquefied under pressure. The classification of LPG sometimes also includes a handful of other hydrocarbons that can be found in commercial applications. The specific number classified as LPG can vary slightly depending on regulatory definitions and geographical considerations, but typically, the broader classification includes propane, butane, isobutane, and other related hydrocarbons.

Selecting six as the answer reflects an understanding that, in addition to propane and butane, other similar compounds might be considered under the umbrella term of LPG, which is commonly used in various applications from cooking to heating. This choice accurately represents the conventional categorizations of gases that share similar properties and uses, which are grouped together within the industry standards and emergency response guidelines.