pH in cleaning
Why the acid or alkali choice decides both what a cleaner removes and what it damages. The two are the same property seen from opposite sides.
In detail
pH measures how acidic or alkaline a solution is, and in cleaning it is the single most useful predictor of what a product will do. Acids dissolve mineral deposits: they react with carbonates, which is what removes limescale, and they help with rust and some metal staining. Alkalis attack organic soil: they break down fats into soaps and hydrolyse proteins, which is what makes them effective on grease and food residue. Because the mechanisms are chemical reactions with the soil, they are also chemical reactions with anything else made of the same stuff. An acid that dissolves carbonate scale dissolves carbonate stone. An alkali that hydrolyses a protein stain hydrolyses a wool fibre. This symmetry is the most reliable rule of thumb in the subject: the more strongly acidic or alkaline a cleaner is, the more effective it is on its target soil and the narrower the range of surfaces it can safely touch. A near-neutral surfactant cleaner sits at the other end — less potent, and safe on far more.
Why
- Grout is explained by pH in cleaning
- Citric acid is explained by pH in cleaning
- Acetic acid (vinegar) is explained by pH in cleaning
- Descaling is explained by pH in cleaning
- Wood ash is explained by pH in cleaning
- Sodium carbonate is explained by pH in cleaning
A considerably stronger alkali than bicarbonate, and the strength is both what it is for and what restricts it.
- Sodium hydroxide is explained by pH in cleaning
- Sodium bicarbonate is explained by pH in cleaning
Sprint 29. The weaker half of the pair the register has always described together.
Sources for this page
Sources
Cleaning product science and ingredient information
American Cleaning Institute (ACI) · Trade or professional body
Relied on for: That cleaning products are formulated across a pH range according to the soil type targeted.
Verification: the work exists and is described correctly. Nobody has yet read the specific passage.
Kirk-Othmer Encyclopedia of Chemical Technology
John Wiley & Sons · Reference work
Relied on for: That alkaline hydrolysis acts on fats and proteins, and that acids react with carbonates to form soluble salts.
Verification: the work exists and is described correctly. Nobody has yet read the specific passage.
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