Editor’s note: This summary article was extracted from an article title “The science of disinfectants,” written by Kirsten Thompson and originally appeared in Cleaning & Maintenance Magazine.
Every company/industry uses some sort of disinfectant at their facility. Often, without even realizing it, we take advantage of the actions of disinfectants. This is because a lot of the times we do not understand how they work to their fullest potential. There is not only major differences in the chemicals used in disinfectants, but also how they work. For the most part disinfectants have a few major ways in which they kill harmful organisms. These ways are by cross-linking, coagulating, clumping; structure and function disruption, and oxidizing.
One of the major chemicals in disinfectants is alcohol. The main way that alcohol attacks disinfectants is by cross-linking, coagulating, and clumping. Alcohols are normally considered to be non-specified anti-microbial. This is due to the fact that alcohols tend to have many toxic effects.
So how does alcohol attack organisms? One of the main way it does this by causing cell proteins to clump and lose their function. What it does is attacks the cells membranes. This causes the cells to lose their structures and collapse, ultimately killing them.
In order to receive the full effect alcohol must be diluted with water. This is because proteins are not denatured as easily with just straight alcohol.
Another thing alcohol does is inhabits spore germination. This is done by affecting the enzymes necessary, but once its removed spores can recover.
Another key chemical used for disinfecting is chlorine. The way chlorine kills off organisms is by oxidizing. Chlorine is one of the most common disinfectants. It is used in numerous amounts of cleaning solutions, and can even be found in drinking water (this is because even in the smallest of amounts it acts fast with killing bacteria).
Chlorine kills bacteria by oxidizing proteins, lipids, and carbohydrates. When chlorine dissolves in water Hypochlorous acid is formed. Hypochlorous acid attacks the bacteria’s cell by targeting key metabolic enzymes, ultimately destroying the organism.
Chlorine compounds also affect the surface antigen in enveloped viruses and DNA. It also causes structural altercations in non-enveloped viruses.
Even though very few chemicals are sporicidal, chlorine compounds with high concentrations have killed bacterial spores such as Clostridium Difficile.
Peroxygen Compounds are another key chemical that is in disinfectants. Peroxygens attack organisms through oxidization too. Two major peroxygen compounds are peroxide and peracetic acid. When trying to control infections these two chemicals play a major role. Unlike other disinfectants these two compounds are not affected by the addition of organic matter and salts.
When Peroxygen compounds are exposed to the air a highly reactive ion is formed what is known as hydroxyl radical. This ion is deadly and kills many forms of bacteria because it is a strong oxidant. Hydroxyl radical attacks key cell components/membranes, which results in the cell collapsing.
Peroxygen compounds eliminate spores. This is done by removing proteins from the spores coat and exposing its core to deadly disinfectants.
A fourth chemical that helps kill bacteria is phenol. The main functions of phenol is cross-linking, coagulating, and clumping.
Phenol and its byproducts display numerous types of bactericidal actions. At high concentrations, phenol will infiltrate and disrupt the cell wall. This will make the cell proteins fall out of suspension.
One of the first things to happen is the stopping of essential enzymes. Next, the bacteria’s membrane loses its ability to act as a barrier to physical or chemical attack.
Even though phenols act at the beginning stages of bacterial spore development, this effect can be reverse. Therefore this makes them unsuitable as a sporicide.
The final compound that will be mentioned are quaternary ammonium compounds. The main objective of them is structure and function disruption.
Quaternary Compounds, quats for short, are some of the most widely used disinfectants due to their broad variety effectiveness. They work by denaturing the proteins of the bacterial cell. This affects the metabolic reactions of the organism. This causes vital substances to leak out of cell, which ultimately causes death.
Since quats are a charged, you have to be aware of “quat absorption.” This occurs when quat molecules are attracted and bound to anionic (negatively charged fabric surfaces). You can solve quat absorption by using wipes made from nonreactive textiles. Also, you can increase the solution concentration to compensate for absorption.