Harley Ryland
Most cleaning problems are chemistry problems.
When a cleaner isn't working, the first instinct is often to reach for something stronger. But stronger chemistry isn't necessarily the answer. Sometimes you simply need a different type of chemistry.
Understanding a few basic concepts about acids, alkalis, surfactants, and solvents can help you match the cleaner to the contamination instead of guessing.
That means faster cleaning, less wasted product, less unnecessary scrubbing, and a lower chance of damaging the surface underneath.
Acids and Alkalis: Understanding pH
The pH scale runs from 0 to 14, with 7 considered neutral. Values below 7 are acidic, while values above 7 are alkaline.
The scale is logarithmic. A change of one pH unit represents roughly a tenfold change in hydrogen ion activity.
But here's the important part:
That does not mean a pH 13 cleaner is simply “ten times stronger” at cleaning than a pH 12 cleaner.
Cleaning performance depends on the complete formulation, including concentration, builders, surfactants, solvents and the soil being removed.
Acidic cleaners are commonly used against mineral-based contamination such as hard-water deposits, mineral scale, efflorescence and certain rust stains.
Alkaline cleaners are commonly used against organic and greasy contamination, including fats, oils and many types of shop and industrial grime.
This is why many heavy-duty degreasers are alkaline while products designed for mineral deposits often fall on the acidic side of the pH scale. Neither is universally “stronger.”
They're different tools for different problems.
Surfactants: Helping Water Do Its Job
Water has high surface tension and doesn't naturally interact well with many oily soils.
That's where surfactants come in.
Surfactant molecules contain portions that interact differently with water and oily contamination. This allows them to improve wetting, loosen soils and help suspend oily contamination in the cleaning solution so it can be carried away during rinsing.
That's why people sometimes describe surfactants as making water “wetter.”
Different surfactants can be selected for different jobs. A formulation may be designed around wetting, detergency, emulsification, foam characteristics, rinsing or combinations of those properties.
And that's an important lesson in cleaning chemistry:
A well-designed cleaner isn't necessarily the product with the highest or lowest pH.
The entire formulation has to work together.
Solvents: When Water Isn't Enough
Solvents work differently. Rather than relying primarily on aqueous detergency, solvents can dissolve or soften soils that have an affinity for the solvent being used. That makes certain solvents particularly useful against petroleum contamination, tar, adhesives, oils and other stubborn residues.
But there's another important distinction:
Water-based does not mean solvent-free.
Many water-based cleaners contain water-soluble solvents or co-solvents alongside surfactants, builders and other ingredients.
Formula 85 is a good example. It's a water-based alkaline cleaner that also uses solvent chemistry as part of its overall cleaning system.
So when we describe a cleaner as “water-based” or “solvent-based,” we're generally talking about the overall cleaning system and primary carrier, not whether the formula contains a single ingredient that can be classified as a solvent.
For a deeper look at that distinction, see our Water-Based vs. Solvent-Based Degreasers guide.
Real Cleaners Combine Chemistry
Acids, alkalis, surfactants and solvents aren't necessarily four completely separate categories of finished products. They're pieces of a formulation. A heavy-duty water-based degreaser might combine alkalinity, builders, surfactants and a water-soluble solvent. Another cleaner may depend heavily on surfactants while remaining relatively mild in pH. The performance comes from how those ingredients work together. That's why choosing cleaning chemistry based solely on color, smell, foam level or pH can be misleading.
Start with three questions:
- What contamination am I trying to remove?
- What surface is underneath it?
- What cleaning process can I use?
Then choose the chemistry accordingly.
Dwell Time Is Part of the Process
Even the correct chemistry needs an opportunity to work.
Dwell time gives a cleaner contact with the contamination before agitation or rinsing. Depending on the formulation, that time may allow surfactants to wet and loosen soils, alkaline chemistry to attack certain greasy contamination, or acidic chemistry to react with mineral deposits.
But more dwell time isn't automatically better.
Follow the manufacturer's directions, consider the surface and environmental conditions, and don't allow a cleaner to dry on the surface unless the product specifically permits it.
Heat, agitation, pressure and concentration can also change cleaning performance. Sometimes the best way to improve a cleaning process isn't adding more chemical. It's giving the chemistry you're already using a better chance to work.
Match the Chemistry to the Problem
There isn't one universally best cleaning chemical.
A product that tears through greasy equipment may be completely wrong for mineral scale. An acid that removes a stubborn mineral deposit may damage a surface that isn't acid-resistant. A powerful solvent may be unnecessary when a diluted water-based cleaner can do the job.
The goal isn't to find the harshest cleaner on the shelf.
It's to use the right chemistry, at the right concentration, on the right surface, with the right process.