An aqueous, concentrated neutral detergent composition for use in cleaning medical instruments and metal components (parts, tools, utensils, vessels, equipment, and surfaces) having scale control and corrosion inhibition properties when diluted to about 1/40 ounce per gallon to about 1/10 ounce per gallon in potable water. In addition, the concentrate may be applied directly to metal surfaces, such as stainless steel, to remove rust and other stains, without causing any additional corrosion or other damage to the metal surface.