Color stable hypochlorous sanitizer and methods.

摘要

Manual warewashing in common food service locations is typically performed in a multicompartment sink within three or more basins. In one basin the ware is contacted with an aqueous solution of a detergent composition. The ware is cleaned using mechanical action to remove soil. The cleaned ware is often rinsed in a subsequent sink in a potable water rinse and is then sanitized in a sanitizing solution in a subsequent basin, typically the third sink in sequence. The sanitizing solution can be rapidly depleted during periods of large volumes of hand washed ware. In order to monitor and control the concentration of the sanitizer in the sanitizer sink, we have found that even highly oxidizing hypochlorite bleaches, if adjusted to an appropriate pH, can maintain substantial sanitizing capacity while not decolorizing otherwise oxidatively sensitive dyes. In the method of the invention, the sanitizing solution adjusted to a pH of less than about 7 containing a dye can maintain a stable dye solution for a period of time greater than the time required to deplete 90% or more of the OCl-1 in solution. As a result, the hand washing staff can have a satisfactory indication of the existence of active sanitizer in the sanitizer step based on the presence of color in the aqueous solution.