This is a fully active Muriatic acid based on material used for the removal of scale and rust. (Inhibited against attack on all ferrous metal, brass, copper, stainless steel and most other common metals with the exception of tin, cadmium, zinc and aluminum.) Inhibited Muriatic Acid is used extensively on all types of heat exchange equipment, mechanical washing machines, diesel engine cooling systems, condensers of all types, refrigeration systems, reclaiming rust units such as nuts and bolts, all steam equipment, concrete mixers and ready-mix trucks, coolers, blanchers, brine tanks, etc.