In CO2 snow cleaning, compressed liquid or gaseous carbon dioxide is expelled from a nozzle, condensing into a mixture of solid particles and gas, which impact the surface to be cleaned.[1][4]: 276 Jet velocities are frequently supersonic.[8] Snow cleaning works by a combination of momentum transfer (mechanically dislodging contaminant particles) and solvent action.[1][4]: 273 The CO2 sublimates on contact, increasing in volume up to 800 times, thereby generating pressure to sweep particles away.[8] The CO2 also dissolves hydrocarbon contaminants, and its low temperature embrittles residues such as fingerprints, making them easier to blow away.[2][9]