Ammonia, or its derivatives, is one of the most common cleaning chemicals found in household formulations. If you look on the label of common disinfectants, like pine-o-clean for example, you will see the active ingredient listed as a QAC.
This stands for “quaternary ammonium compound.” Ammonia is the simplest QAC (or “QUAT”). Let’s look at its properties, and why it is such an effective and common cleaning chemical.
There are essentially three properties of ammonia that make it a very versatile cleaning chemical:
1. It’s a disinfectant. It does this by disrupting the cell walls of bacteria:
These compounds penetrate into the bacteria cell wall, reacting with the cytoplasmic membrane inducing wall lysis caused by autolytic enzymes
This in fact is a very common mechanism for disinfectants in general.
2. It is alkaline.
Many cleaning chemicals are alkaline. Drain cleaners and other cleaners typically contain caustic soda – although some of them these days use ammonia-based compounds. Sodium carbonate (washing soda) is by far the most common cleaning chemical and is the basic ingredient in most laundry powders and automatic dishwashing powders.
The reason that alkaline chemicals make such good cleaners, is that much of household grime or stains are the result of animal fats or vegetable oils, and the caustic chemicals are very effective at removing these by the process of saponification.
3. It is volatile.
“Volatile” contrary to popular belief does not mean explosive or flammable. It simply means that it evaporates very easily. And this is a good thing for a cleaning chemical, as any of it left behind after cleaning simply evaporates and there is no residue. This makes it an excellent glass cleaner, because it will evaporate, leaving no residue.
4. It is highly polar.
We have seen that all liquids may be classified as being polar or nonpolar (with a few chemicals in between), and detergents (or surfactants) are able to make the two types of chemicals mix because they are two in one molecules.
Ammonia possesses the property of being the only liquid that is more polar than water, making it the most polar industrial liquid in existence.
This has interesting implications. The only difference between soap and soap scum is the metal that it is attached to. For example, sodium stearate is soap, and calcium stearate is soap scum. The difference simply is that the sodium salt is soluble in water and the calcium salt isn’t.
But if you have an even more polar liquid than water – like ammonia – then maybe the calcium salt (the soap scum) is soluble.
For this reason, there are some that recommend it as a shower screen cleaner.