Cleaning validation procedures are carried out in order to assure that residues of cleaning agents are within acceptable limits after the cleaning process. Cleaning agents often consist of a mixture of various surfactants which are in a highly diluted state after the water rinsing procedure has been completed. This makes it difficult to find appropriate analytical methods that are sensitive enough to detect the cleaning agents. In addition, it is advantageous for the analytical methods to be simple to perform and to give results quickly. In this study, three different non-specific analytical methods are compared: visual detection of foam, pH and conductivity measurements. The analyses were performed on different dilutions of the cleaning agents Bactericidal Hydroclean and Tickopur R33. The results demonstrated that the most appropriate method for these detergents are conductivity measurements, by which it is possible to detect concentrations of cleaning agents down to 10 µg/ml. In this case, pH is an inadequate method (non-linear) and visual detection of foam is a semi--quantitative method. All these methods are easy to perform, gives a quick results, and requires no expensive instrumentation.The main objective of cleaning validation procedures is to provide documented evidence that the equipment is safe for the manufacture of the next product. For this purpose, cleaning agents are used for removal of the previously manufactured product and also for the removal microorganisms. Because cleaning agents often consist of a mixture of various surfactants, often very diluted, it may be difficult to find appropriate analytical methods that are sensitive enough for detection of the compounds.The first step in cleaning equipment is the selection of an appropriate cleaning product for the type of residue to be removed. Once this is done, an analytical strategy must be devised to determine the amount of cleaning agent residue left on surface that has been cleaned. This determination is important because if a cleaning agent effectively removes the drug--product residue but leaves behind its own residue, then one type of contamination has been exchanged for another, and the equipment has not been cleaned effectively. Detergent selection is a critical step in the Correspondening author: D. Milenović, "Zdravlje-Actavis" Company, 199 Vlajkova St.,