Choosing the right truck wash soap will go a long way to ensuring your fleet stays clean and runs smoothly for years to come. But there are many different types of chemicals in your detergents and soaps. Some consist of corrosive ingredients and it can be important to know if they are safe for your fleet or the people using them. 

In this blog, you’ll learn about some of the main ingredients in truck wash cleaning products, why they’re used, and how to know which one is right for your fleet.


Common Fleet Washing Detergents and Why They Are Important

Whether you’re a commercial fleet washer or manage your own fleet, understanding which ingredients are in your truck wash soaps is important. Otherwise you run the risk of damaging your truck surface, etching the glass, or just being ineffective. 

There are many different chemicals used in your truck wash soaps. But these can be broken down into two main categories:

  1. Acids / Low pH chemicals
  2. Alkalines / High pH chemicals


What is the Difference between Low pH and High pH?

Every truck wash detergent is measured by either being an acid aka low pH OR as an alkaline aka high pH.  

The pH scale ranges from 0 - 14, with a pH level of seven being neutral. Any pH level less than seven is considered acidic. Any pH level above seven means your truck wash detergent is base or alkaline.

Acids and Low pH Chemicals

Knowing there are acids in your truck wash soaps can feel intimidating. But not all acids are bad. In fact, there are many everyday items that are technically acidic but aren’t harmful; things like coffee or even red meat.

Almost all low pH presoaks are blends of different acids. Small amounts of low pH acids like hydrofluoric (HF), sulfuric, phosphoric, hydrochloric, ammonium bifluoride (ABF), and citric are common ingredients in many truck wash low pH detergents.  

That’s because they are highly effective against inorganic materials and minerals like dust, lime, or salt. They are also great for removing discoloration and oxidation from various metals, and brightening the aluminum for the fleet industry.  

Here are a few common acids in your truck wash soaps:

  • Hydrofluoric - Very effective but corrosive acid for brightening non-polished aluminum, removing oxidation from paint, and extremely cost effective solution.
  • Citric - Typically Non-Corrosive, removes oxidation from paint, some stains associated with minerals like iron ore, and is favored due to its pleasant smell and safety of it.  
  • Sulfuric - Very effective at removing stains from minerals, but is also corrosive in any strength.  Sulfuric is similar to  hydrofluoric acid in that it is typically a much more cost effective ingredient relative to some of the safer counterparts.  
  • Hydrochloric (aka Muriatic) - at higher strengths it's typically used to target specific uses in heavy duty applications such as cement, concrete, rust stains, or fly ash. It is still used within blends with other acids but at a much lower strength.
  • Phosphoric - Similar to citric acid, it tends to be on the less corrosive side, but acts as a very mild aluminum brightener, helps remove oxidation from paint, and generally is used in "safe on polish" cleaning options for fleets.  

Alkalines and High pH Chemicals

Alkalines are on the opposite side of the pH scale to acids. They are used to break down the carbon based soils that are on the vehicle's surface.  

They are effective against grease, oils, proteins, and other organic material. Some common alkaline chemicals include:

  • Sodium Metasilicate - helps boost the pH to maintain its alkaline properties, helps ‘cling’ to the surface, and is a non-corrosive ingredient. 
  • Sodium Hydroxide - Corrosive alkaline ingredient, but highly effective to attack grease, oils, proteins, and other carbon based soils, and very reactive.   
  • Potassium Hydroxide - Not as reactive as sodium hydroxide, but still very effective against carbon based soils, grease, oils, fats, etc.  

Other Chemicals

Butyl is another popular ingredient that can be interjected into an acid or alkaline base product to assist with breaking down oils that are common in our industry on the hoods and driver side doors of trucks.  Butyl is a water soluble ingredient found in many high pH alkaline truck wash detergents and degreasers and occasionally added to low pH acidic cleaners.


Why Using Both Low pH & High pH Chemicals is Helpful

Road film is a thin layer of dirt, smoke, and other contaminants that get stuck to the surface of your vehicles. It can be extremely difficult to remove, even if you brush your truck thoroughly. 

That’s because when air passes over the surface of the vehicle as it travels down the road, it creates an electrostatic bond and gives it a strength similar to a magnet. In order to rinse this film off, the bond must be broken. The fastest way to do this is by applying a 2-step chemical application process followed by a rinse.  You would apply a low pH acidic detergent as your step 1, followed by an alkaline step 2 detergent to neutralize the "electrostatic bond" so that you can easily rinse away the road film. 

By using both low pH and high pH chemical detergents, you’re more likely to remove both the positive and negative charges that create road film. In addition, using both makes sure to assist in the removal of all kinds of dirt and grime on the vehicle; the low pH targets oxidation and inorganic materials such as minerals while the high pH targets the organic, carbon-based materials such as grease and oil.  


The Bottom Line

Each truck wash detergent has a purpose and when used correctly, is highly effective at cleaning your vehicles. If you use the wrong chemical, you could damage your truck or cause injuries. That’s why it’s important to know the chemicals in your detergents and how to best use them. Always consult the manufacturer of your truck wash detergents.  To improve your truck wash process further, make sure you follow the five major cleaning factors.


About Hydro-Chem Systems

Hydro-Chem Systems is a leading manufacturer  of fleet and industrial truck cleaning solutions. For more than 50 years, we’ve dedicated ourselves to helping private fleet owners, municipalities, schools, farms, manufacturers, and mobile washers across the USA & Canada achieve the lowest cost per wash. To find more information on how you can clean more vehicles in less time, call 616-531-6420 or email us at

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