Automatic dishwashing tablets with improved chlorine stability

A method for increasing chlorine stability of a pressed automatic dishwater detergent tablet having a chlorine source in an amount sufficient to provide 0.5 to 5 percent available chlorine, said method comprising incorporating a nonionic surfactant into the dishwasher detergent tablet in an effective chorine stability enhancing amount of between about 1 to about 10 percent by weight, said nonionic surfactant having the structure:

• R—(AO1)x(AO2)y—OR′
• wherein
• R is a C6-C18 alkyl group,
• AO1 represents propylene oxide or a mixture of propylene oxide and other alkylene oxides,
• AO2 represents ethylene oxide or a mixture of ethylene oxide and other alkylene oxides,
• R′ is an alkyl or arylalkyl group with 1 to about 10 carbon atoms,
• x is 2-20, y is 0-20, and the sum of x plus y is 5 or greater, wherein y is non-zero and
• wherein the surfactant is present so as to achieve a chlorine stability of the tablet such that greater than 80 percent of the chlorine in the table remains active for eight weeks when the tablet is stored at 120° F.