physical or chemical attack. Though phenols can act at the germination — beginning of growth — stage of bacterial spore development, this effect is reversible, making them unsuitable as sporicides. Quaternary Ammonium Compounds Mechanism of action: Structure and func-tion disruption. Quaternary ammonium compounds (quats) are some of the most widely used disinfectants today because of their broad spectrum effectiveness. Quaternary ammonium compounds work by denaturing the proteins of the bacterial or fungal cell, affecting the metabolic reac-tions of the cell and causing vital substanc-es to leak out of the cell, causing death. Because quats are a charged particle, something to consider is “quat absorption,” which is when quat molecules are attracted and bound to anionic — negatively charged — fabric surfaces. For example, if a pail contains the cor-rect dilution of a disinfectant with an active ingredient concentration of 800 parts per million (PPM), that concentration could be reduced by as much as half after a cotton wipe is placed in the solution and allowed to soak for 10 minutes. Some ways to solve quat absorption include using wipes made from nonreactive textiles and increasing the solution concen-tration to compensate for absorption. The Right Stuff While each of the chemicals described above are effective in certain applications, formulations are also made more or less effective by their other ingredients. In particular, surfactants are often impor-tant ingredients to disinfectant cleaning solu-tions because they achieve uniform wetting of surfaces and frequently help with cleaning. Something to consider is that some sur-factants contain positively-charged ions, which can inactivate negatively-charged antimicrobials like quaternary ammonium compounds by binding with them, making them less effective against a microbe. In contrast, low surfactant concentra-tions may improve the microbiocidal effect. The reason for the improved action is thought to be an accumulation of the agent within micelles of the surfactant, which absorb to the microorganism’s cell wall. The active substance thus becomes enriched at the cell wall, which means that a lower dose is required for the desired effect. While chemistry is important, even the best formulations will not be effective if applied incorrectly or inconsistently. Other processes and interventions must also be in place to ensure that all areas are cleaned thoroughly each time. Understanding how different chemistries work can help you evaluate which ones are best suited to your facilities’ needs. CM Still using two products to clean and disinfect? Spic and Span All-Purpose Spray and Glass Cleaner cleans and disinfects mirrors, counters and more in Before Everyday germs and bacteria After 99.9% Germs and bacteria eliminated * a single, simple step. To learn more or request a free demo, visit us at www.pgpro.com or call 1.800.817.6710 * when product used per label instructions. © 2012 P&G Product Information no. 201 on page 24 www.cmmonline.com 29
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