 Smaller volumes of haze can also be generated from aerosol canisters containing mineral oil under pressure.Although the density of haze generated and the volume of space that can be filled is significantly smaller than that of a haze machine, aerosol canisters have the advantages of portability, no requirements for electricity and finer control over the volume of haze generated.Liquid carbon dioxide (CO2), stored in compressed cylinders, is used in conjunction with theatrical fog machines to produce "low-lying" fog effects.