Gasoline that is still fresh can be safely added to the fuel tank of a vehicle that uses it. Otherwise, gasoline must be disposed of in a hazardous waste disposal facility.
It is never safe to dispose of gasoline in the trash or by dumping it down the drain, into a waterway or onto the ground. This is harmful to the environment and can result in a fire. Gasoline can be safely stored, especially if a fuel stabilizer is added at the beginning of the storage period, though each engine or other gasoline-burning device has a manufacturer's recommended maximum age for the gasoline used. It is important to know that specification before adding gasoline to a car or other piece of equipment.
The best way to dispose of gasoline that is too old to be used varies by location. Often, a municipal dump, recycling center or hazardous materials disposal center is equipped to dispose of old gasoline. The websites for these organizations usually specify what they can or cannot take. Many private waste management companies also offer gasoline and other hazardous materials disposal, though this varies by company. In the case of both municipal and private solutions, there is often a fee associated with disposal.