 Hey everybody, Dr. O'Hare. This video we're going to talk about a couple separate things. We're going to talk about the surfactants, but we're going to talk about soap separately. And then we're going to talk about quaternary ammonium compounds, which are some of the most commonly used cleaners in the world. So first, surfactants, what they do is they lower surface tension, just like the surfactant in your lung does. Lungs do. They are the major ingredients in both soaps and detergents. So I actually didn't know this too long ago, but soaps and detergents are different. Natural, they come from their byproduct of fats, but they leave, especially if you have hard water that has a lot of minerals in it, like calcium and magnesium. That's why they leave this soap film. Detergents don't do that because they're synthetic and they're able to wipe or wash these things away. So I saw that in a really neat example in a chemistry lab. Soaps and detergents are not the same thing. So first of all, just soap. Soap is a terrible antimicrobial. Soap is effective because it physically de-germs or removes microbes. So if I were to ask you on an exam or something about soap, soap isn't antibacterial unless you're talking about antibacterial soap. Soap is effective though because it physically removes and washes away and de-germs. So soap is a de-germing agent. All right, when it comes to the detergents, there are different types of detergents, anionic and cationic detergents, but we only care about the one major group. They would be called cationic detergents, but I don't think it's a huge deal. This very important class of disinfectants that are called the quaternary ammonium compounds, you see them called the quaternary ammonium salts here, they're referred to as quats usually. So when someone's talking about a quat, they're talking about a quaternary ammonium compound. So here's how they work. This is what makes them amazing. So here's two examples of sedyl pyridinium chloride and benzochronium chloride. These are the two most important quats. They actually can insert themselves like you see in this wonderful picture. They insert themselves right into the plasma membrane. And disrupt it. So that's going to be how they work. They're disrupting the phospholipid bilayer of a cell right there by inserting themselves right where the phospholipids should be sitting. So where are these used? Man, they're all over the place. Many of your Lysol branded products are going to have benzochronium chloride in it. You're seeing it more and more, especially as triglysanis being removed from a lot of your antibacterial products. You're seeing more of these quats being added to these things. So they're on your skin antiseptics. So they're replacing alcohol in some of your hand sanitizers as well. Oral rinses, mouth washes, you name it. And like I mentioned before, these quaternary ammonium compounds are often the most common ingredient in cleaning products used in the healthcare setting. So you are most likely working with some form of a quat. All right. So that is soap as a surfactant and a de-germing agent. And then the quaternary ammonium compounds or the quats, both get rid of microbes but soap just physically removes them. The quats actually can be disinfectants and antiseptics. All right. I hope this helps. Have a wonderful day. Be blessed.