The article presents the results of substantiation of composition of technological aids for treatment of casings, which provides an increase in microbiological safety of the finished product. The study objects were samples of casings with signs of microbial spoilage, provided by the manufacturer, and prototypes of technological aids for treatment of casings obtained in VNIIPD. Parameters studied: microbial contamination of casings; titratable acidity, active acidity, density of test samples of the technological aids, surface tension and efficiency of aqueous solutions of the samples. Microbial contamination was determined using methods generally accepted in veterinary and sanitary examination; titratable acidity — titrimetric method; active acidity (pH) — potentiometric method; density — densimetric method; surface tension — ring method (du Noüy method). It was found that the surface microbial contamination of defective intestinal membranes includes the following microorganisms: Bacillus spp., Enterococcus spp. and Micrococcus spp. Among the microorganisms the most resistant to various types of treatment are Bacillus spp. microorganisms. It was established, that the samples of the tested synthesized prototypes of technological aids with most effective antimicrobial action were samples based on lactate-, acetate- and propionate-containing additives, including polyhexamethylene guanidine hydrochloride and alkyldimethylbenzylammonium chloride. It was shown, that test prototypes 9, 19, and 28, which include polyhexamethyleneguanidine hydrochloride, alkyldimethylbenzylammonium chloride and polyvinylpyrrolidone, have rather high antagonistic activity against test cultures of L. monocitogenes, E. coli, St. aureus, Sal. typhimurium with the folowing concentration — (600 × 106 CFU/ml). Minimum effective concentrations of solutions of technological aids for treatment of casings vary from 0,6 % up to 2,5 %. It was established that minimum effective concentration of solutions of technological aids for treatment of casings corresponds to concentration of the solution with maximum adsorption of the resulting complexes on the surface of the liquid-air phase boundary. Treatment of defective casings with aqueous solutions of the agents with concentrations of 2.5 % for 30 minutes provides suppression of growth of all detected spoilage microorganisms, including Bacillus spp.