Thickening system for incorporating fluorescent whitening agents

A freeze-thaw stable thickening system for laundry products incorporating low levels of an acid-insoluble fluorescent whitening agent, a nonionic surfactant that comprises substantially of hydrophilic polyethoxylated alcohol oligomers, a fatty acid soap, and acidic pH adjusting agent is provided. The thickening system may be formulated with a bleaching product and preferably with a peroxide bleach product. Preferred polyethoxylated alcohol oligomers comprise a mixture of alcohols having the structure CH3(CH2)n(OCH2CH2)xOH wherein n is about 11 to about 14 and x is from 0 to about 20 and wherein the average number of ethylene oxide groups per molecule is about 6-10, and preferably about 7. Preferably the total amount of polyethoxylated alcohols having x equal to 0, 1, or 2 comprise less than about 10% by weight of the mixture of polyethoxylated alcohols.