Cleaning systems designed to transport and store pure liquid oxygen requires the greatest care and enormous attention to safety because almost any residue or contamination could cause a catastrophic explosion. The design of these systems makes cleaning even more difficult. Tubing can wind through fuselages or airplanes or the utility channels of a hospital. Gauges, pumps, filters and valves all can entrap contaminants. The contamination is widely variable: from simple particulate to challenging residues from assembly. Lastly, cleaning is made even more complex since mechanical scrubbing usually is not possible.
Obviously, slow-drying fluids such as water are unacceptable because they could be trapped in the system. Flammable liquids, such as alcohols, also are unacceptable for safety reasons.
Oxygen system cleaning must be performed with nonflammable, fast-drying, residue-free cleaners. These include: