This invention relates to a semi-quantitative diagnostic tool and a method for using the same to verify the efficacy of cleaning-in-place procedures in eliminating carbohydrate-based, organic residues from product contact surfaces in food, beverage and pharmaceutical manufacturing, processing and packaging facilities. The diagnostic tool comprises a permanganate-based colorimetric indicator formulation and a translucent assay container for containing the permanganate-based colorimetric indicator formulation. The diagnostic tool is characterized therein that the permanganate-based colorimetric indicator formulation is admixed with a product sample to be tested so that the admixed permanganate-based colorimetric indicator formulation undergoes a colorimetric reaction in the presence of organic residues in the product sample, the arrangement being such intensity of the colorimetric reaction displayed provides a semi-quantitative determination of a concentration of organic residue dissolved or suspended in the product sample.
