What is an alkaline aqueous solution?
Alkaline aqueous solutions are water-based mixtures with a pH greater than 7. Most of these types of cleaners range from a pH of 10 to 14
. Simple Green All-Purpose Cleaner
is a water-based cleaner with a pH of 8.5 to 9.5. Alkaline aqueous solutions are the most common solutions in water based cleaning. These often contain additives to improve cleaning, such as mineral and metal sequestering agents, emulsifiers and surfactants. Corrosion inhibitors may be necessary with some metals, especially aluminum.
Alkaline aqueous solutions remove foods, fats, grease, coolants, cutting oils, dirt, fingerprints, cosmoline, some water-soluble paints and more. They are also used with all types of liquid processes, e.g., spray, ultrasonic, immersion and power washers. These solutions can clean to very high levels, with good filtration and rinsing. Cost per gallon is generally less than for semi-aqueous cleaners.
What are high-alkaline, water-based cleaners, and are they hazardous?
The cleaning principle of these products is that the alkaline (high pH) strips the oil from the substrate (surface) and floats it on top of the water, thus allowing re-deposition of oil on the substrate (resulting in poor rinse ability.) Other problems with this type of aqueous cleaner is that higher alkalinity often creates health and safety issues (i.e., chemical burns, choking vapors, the need for costly protective equipment, disposal difficulties, etc.) High-alkaline cleaners also cause problems for sewage treatment plants.