Portable generator gas tanks are frequently made of plastics similar to those used for portable gas cans, though some gas tanks are fashioned from metal. Large tanks are more likely to be made from metal, but the weight of metal tanks makes them less suitable for portable use.
Portable generator gas tanks typically range in capacity from 5 to 18 gallons of fuel regardless of the material from which they are made. In some cases, a larger 55-gallon metal drum may be useful as a portable generator fuel tank if it is possible to transport it with a vehicle along with the generator. All portable generator gas tanks must be compliant with Environmental Protection Agency guidelines to prevent spillage and reduce fire and explosion risks.