Alkaline Aqueous Overview Alkaline aqueous solutions are water-based mixtures with pH greater than 7. Most alkaline cleaners range from pH 10 to 14. They are the most common solutions in aqueous cleaning. Alkaline cleaners often contain additives to improve cleaning, such as sequestering agents, emulsifiers, and surfactants. Inhibitors are necessary with some metals, especially aluminum. These compounds can remove greases, coolants, cutting oils, shop dirt, fingerprints, cosmolene, petrolatum, and some water-soluble paints. Parts cleaned with alkaline cleaners include hydraulic valve bodies, fuel injector components, and machined aluminum castings. Alkaline solutions are used with all types of liquid processes, e.g., sprays, ultrasonics, immersion, and power washers. These solutions can clean to very high cleanliness levels with good filtration and rinsing. Cost per gallon is generally less than for semiaqueous cleaners. Do not automatically assume that alkaline aqueous solutions can be disposed of down the drain. The local water treatment authority or publicly owned treatment works (POTW) will have information on treatment and disposal of these cleaners. Adjustment of pH and dilution are usually required before disposal to a drain. State Information | Glossary | Conversion Checklist | Comments Home | Process Advisor | Alternatives | Links | Search All SAGE material, Copyright© 1992, Research Triangle Institute Last Update: 06 May 1997 sage@rti.org http://clean.rti.org/alt.cfm?id=alk&cat=ov