TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The chemical stabilizer is sodium bisulfite, sodium metabisulfite, potassium metasulfite, sodium hydrosulfide, titanium sulfate, and/or derivatives of these compounds. The alkaline agent is sodium hydroxide, sodium carbonate, sodium triphosphate, sodium metasilicate, and/or sodium silicate.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The cellular membrane disruptor is disulfide bond breaker(s), preferably ascorbic acid, lactic acid, gallic acid, ellagic acid, glycolic acid, thioglycolic acid, N-acetyl cysteine, 2-mercaptoethanol, quinone, polyphenol, proanthocyanidin, aldehyde, and/or derivative of these compounds. The composition further comprises chemical stabilizer(s), preferably oxalic acid and/or its derivatives. The diluent is water, glycol, isopropanol, ethanol, and/or methanol. Preferred Properties: The synergy index of biocidal agent and cellular membrane disruptor is less than 1 but not greater than 0.51. Preferred Composition: The composition is in powder form comprising 8-14 wt.% quat. ammonium compound, 1-6 wt.% cellular membrane disruptor, 1-6 wt.% nonionic surfactant(s), 0.5-1.5 wt.% chemical stabilizer(s), and 0.01-4 wt.% alkaline agent(s). The composition may be provided as dilutable concentrate used to make 1:256 or preferably 1:128 dilution and comprising 8-14 wt.% quat. ammonium compound, 1-6.5 wt.% disulfide bond breaker, and 0.5-1.5 wt.% chemical stabilizer(s); or as ready-to-use biocidal composition having a pH of 6-9 (preferably 6.5-7) and comprising 0.01-1 wt.% quat. ammonium compound, 0.01-5 wt.% disulfide bond breaker, and 0.05-1.5 wt.% sodium bisulfite. The composition is free of metal chelators. EXAMPLE - A biocidal composition comprising (in wt.%) Biosoft 25-7(RTM: nonionic surfactant) (1.50), BTC 885(RTM: blend of alkyl dimethyl benzyl chloride and dialkyldimethyl ammonium chloride) (50% active, 21.70), ascorbic acid (5) and deionized water (71.80) was prepared. The composition was tested according to AOAC Use-Dilution method. The composition demonstrated superior biocidal properties as compared to composition not containing blend of quat. ammonium compounds and ascorbic acid. The composition had faster rate of kill, achieved shortened required contact time, demonstrated broader spectrum of biocidal activity, and did not contain EDTA, as compared to composition not containing blend of quat. ammonium compounds and ascorbic acid.