Cleaning of hard surfaces

A dithionite composition which upon admixture with water forms a solution of pH 5 to 9 consisting essentially of:

• a. 20-60% by weight of a dithionite selected from the group consisting of alkali metal dithionites and zinc dithionites;
• b. 10-50% by weight of a water soluble sulfite selected from the group consisting of alkali metal sulfites and ammonium sulfite;
• c. 5-30% by weight of a metal-complexing agent selected from the group consisting of nitrilotriacetic acid;
• the alkali metal salts of nitrilotriacetic acid, ethylene diamine tetraacetic acid;
• the alkali metal salts of ethylene diamine tetraacetic acid;
• citric acid;
• the alkali metal salts of citric acid;
• gluconic acid;
• the alkali metal salts of gluconic acid;
• d. 0.3-5% by weight of an activator for said dithionite, wherein said activator is selected from the group consisting of OH.sup.-, Cl.sup.-, Br.sup.- or NO.sup.-.sub.2 substituted benzoquinone;
• OH.sup.-, Cl.sup.-, Br.sup.- or NO.sup.-.sub.2 substituted naphthoquinone, and SO.sub.3 H.sup.- or OH.sup.- substituted anthraquinone;
• e. 1-15% by weight of a thickening agent in an amount sufficient to result in said composition having a viscosity of about 20 to about 100 centipoises when admixed with water, said thickening agent being selected from the group consisting of derivatives of polysaccharides and hydroxyethylcellulose;
• and
• f. optionally 0-10% by weight of an anionic or nonionic organic surface active agent, and 0-40% by weight of sodium sulfate.