Not really sure what “pH” means, aside from the fact it has something to do with swimming pools? If so, you may want to continue reading… In fact, anyone who regularly does cleaning should know the pH scale. This applies even more so to those who do cleaning as part of their job and want to work in a competent and professional manner.

The first thing you need to know is that pH means potential hydrogen, which is the measure of acidity or alkalinity of an aqueous solution. The pH scale is therefore used to determine the acidity/alkalinity of a solution or a cleaning product. This scale is marked from 0 to 14, with 0 being the most acidic and 14 being the least acidic (or most alkaline). The midpoint of this scale is 7, which is neutral. For example, the pH of distilled water is 7, which is considered the most pure neutral solution possible.

Here is the pH for a few common solutions:

Acidic Solutions Alkaline Solutions
Vinegar = pH of 2.9 Saliva = pH of 6.5-7.2
Orange juice = pH of 3.5 Blood = pH of 7.4
Beer = pH of 4.5 Egg white = pH of 7.8
Milk = pH of 6.5 Bleach = pH of 12.0

Cleaning products fall into two main families: detergents and disinfectants. Products with a pH below 7 are acidic and have descaling properties, whereas products with a pH above 7 are alkaline (or basic) and have degreasing properties. A product’s pH therefore determines its best use: descaler (strong acid with a pH of between 2 and 0), scrub (weak acid with a pH of between 5 and 2), multi-purpose (neutral with a pH of between 5 and 9), degreaser (alkaline with a pH of between 9 and 14) or stripper (strong alkaline with a pH of between 13 and 14).

It’s also important to know that the pH is a logarithmic scale. This means that if the pH of a solution decreases by one unit, the solution becomes ten times more acidic. If its pH decreases by two units, the solution becomes 100 times more acidic.

This is why cleaning chemicals should NEVER be mixed, especially those at either end of the pH scale, as dangerous chemical reactions may occur. Mixing could also neutralize products, rendering them totally ineffective.

When it comes to cleaning products, most dirt and soil can be removed with just two products: an alkaline product (for substances of plant, animal or human origin) and an acid product (for substances of mineral, metallic or saline origin). There’s no need to use all sorts of cleaning products – just the right ones!