cleaning. Do not use it on painted surfaces. Safety solvent is not suitable for oxygen systems. It can be used for other cleaning in ultrasonic cleaning devices. Apply it by wiping, scrubbing, or booth spraying. The term safety solvent is derived from its high flash point. Many later-issue maintenance manuals refer to safety solvent as 1,1,1-trichloroethane. Methyl Ethyl Ketone (MEK). Methyl ethyl ketone (MEK) is a cleaner for bare-metal surfaces and areas where MIL-S-8802 sealant is to be removed. Normally, you apply MEK over small areas with wiping cloths or soft bristle brushes. CAUTION Avoid prolonged breathing and skin con- tact of MEK. Use MEK only in well-venti- lated spaces. Use extreme care when working around transparent plastics because MEK will damage them upon contact. Trichloroethane. This is a nonflammable degreasing agent for cleaning oxygen systems equipment. It can be harmful to paint and plastic materials and since its vapors are heavier than air, it will displace oxygen in poorly ventilated areas. Ammonium Hydroxide. Normally, you use ammonium hydroxide in the lavatories of aircraft to neutralize urine and waste products. Use a sponge to apply it, and then flush the area with fresh water. Sodium Bicarbonate. Sodium bicarbonate also neutralizes urine deposits. You apply it with a sponge, and then flush the area with fresh water. Sodium bicarbonate is also a neutralizing agent for sulfuric acid battery electrolyte deposits. Sodium Phosphate. Sodium phosphate neutralizes electrolyte spills from nickel-cadmium batteries. Remove spilled electrolyte immediately by flushing with fresh water. Neutralize the area by sponging generously with sodium phosphate solution and then flush with fresh water. Dry with clean wiping cloths. Aqueous Film-forming Foam. Aqueous film-forming foam is commonly known as AFFF. Use it for removing fire-extinguishing agent MIL-F-24385 from aircraft surfaces. Complete details for the use of AFFF as a cleaning agent are in Aircraft Weapons System Cleaning and Corrosion Control. NAVAIR 01-1A-509. Aircraft Surface Cleaning Compound Maintenance personnel use water emulsion cleaners to clean aircraft. These cleaners disperse contaminates into tiny droplets that are held in suspension. The droplets of this cleaner are then flushed from the surface. MIL-C-43616 water emulsion compounds contain emulsifying agents, coupling agents,   detergents, solvents, corrosion inhibitors, and water. Use these compounds on painted and unpainted surfaces in heavy-duty cleaning operations, when materials of lower detergency are not effective. Use these compounds in varying concentrations, depending upon the condition of the surface. Apply water emulsion cleaner by starting at the bottom of the area being cleaned. You may apply the mixed solution by spraying or brushing to avoid streaking. Loosen surface soils by mild brushing or mopping. Then, give the surface a thorough fresh water rinse by using an automatic shutoff-type water spray nozzle. This type of nozzle gives hand control from a light mist or fogging spray to a full spray with high-pressure water. Aircraft cleaning compound MIL-C-85570 is the primary cleaning compound used on naval aircraft. The five types of MIL-C-85570 are discussed in the following text. TYPE I is for cleaning painted and unpainted aircraft outdoors or where enough ventilation is available. It may be used to clean either high-gloss or tactical paint systems. TYPE II is for cleaning painted and unpainted aircraft indoors and in areas of limited ventilation. It is for cleaning either high-gloss or tactical paint systems. Type II is not as good as type I for these purposes. It may also be used outdoors. TYPE III is a mild abrasive cleaner. It is used undiluted for spot cleaning high-gloss paint systems, such as exhaust tracks, shoe scuff marks, and other areas where types I and II are not effective. TYPE IV is a spot cleaner for Tactical Paint Scheme (TPS). For spot cleaning embedded soils on TPS systems without changing the paint finish. TYPE V is for cleaning heavy soils, such as carbonized oil, aged preservatives, grease, and gun blast and exhaust deposits. This cleaner clings to 4-8