Purpose: The purpose of this study was to determine the reduction of Pseudomonas aeruginosa biofilms when exposed to standard and elevated levels of cleaners and sanitizers.
Methods: P. aeruginosa (ATCC 15442) biofilm was exposed to 21 cleaners and sanitizers using ASTM E-2871-12. Most products were tested at three concentrations. Concentrations tested included the standard use concentrations and levels that were significantly higher than is normally used.
Results: The results were grouped into 3 different categories, products with log reductions below 3, significantly above 3, and significantly above 4. The chemicals that demonstrated a log reduction significantly greater than 3 at 95% confidence level were: A mixed halogen sanitizer diluted 1:100 and an undiluted alcohol and quaternary ammonium blend. The chemical concentrations that demonstrated a log reduction significantly greater than 4 at 95% confidence level were: A mixed halogen sanitizer diluted 1:10, a chlorinated alkali cleaner diluted 1:10, chlorine dioxide at 25 ppm, and chlorine dioxide at 100 ppm. All other cleaners and sanitizers tested inactivated less than 3 log of the biofilm.
Significance: The results show that many chemicals that are currently used as cleaners and sanitizers do not kill a P. aeruginosa biofilm at the concentrations that they are typically used, indicating that if biofilm elimination is the goal then the chemicals may need to be used at elevated levels or process changes may need to be used to make them effective against biofilms.