What are Aqueous Cleaners?
Aqueous cleaners are water-based cleaning solutions without volatile organic compounds (VOCs). They may include detergents, surfactants and emulsifiers to aid in cleaning effectiveness. The pH of an aqueous cleaner may range from acidic to neutral to alkaline, but alkaline is the most common.
Video: Aqueous Cleaning Solutions for Industrial Parts
What is Aqueous Cleaning?
The aqueous cleaning method uses water-based solutions to clean industrial parts. Aqueous cleaning agents emulsify and encapsulate contaminants, so they can be easily removed. Heat, agitation, and ultrasonic energy are often added. Rinsing is critical to remove any remaining residues or drag-out. Drying with heated-air dryers or blowers is a final step.
Aqueous cleaning is frequently compared to solvent cleaning, which uses waterless solvents such as BestSolv™ Engineered Fluids in conjunction with vapor degreasing machines to clean parts.
Aqueous cleaning has a reputation for being more environmentally friendly than solvent cleaning. However, both processes require attention to ensure worker safety and environmental protection. Proper treatment and disposal of wastewater is essential, even if the aqueous cleaner is biodegradable, due to material dissolved in the water.
Check out this case study for a comparison of aqueous cleaners vs. solvent cleaning for an aerospace manufacturer. Aqueous cleaning allowed this manufacturer to transition away from the hazards of nPB (n-propyl bromide) solvent cleaning for aerospace parts, to a safer aqueous parts washer solution.
Acidic Cleaner vs Alkaline Cleaner
Aqueous cleaners are available in a range of pH options, from acidic to alkaline, depending on the intended use.
| Category | pH Range | Best For |
| High Acid | <1-4 | Descaling and rust removal |
| Acid | 4-6 | Phosphating, brightening, etching |
| Neutral | 6-9.5 | Removing water-soluble and synthetic oils, lubricants and fluids from newly machined parts. Generally safe on soft metals such as aluminum. |
| Alkaline | 9.5-12 | Removing grease, organic soils, metal chips, salts and oxides. Often used on steel parts. |
| High Alkaline | >12 | Very aggressive caustic chemistry that removes paint, rust, tough oils and grease. |
How to Choose the Right Alkaline Cleaning Solution
The most important factor when choosing an aqueous cleaner or alkaline cleaning solution is the metal substrate, since softer metals require less aggressive chemistry. Be sure that your parts cleaning solution is compatible with the metal parts being cleaned.
Take into consideration the pH of the aqueous solution, as both high alkaline cleaners and high acid cleaners pose risks to worker safety and require extra effort for wastewater disposal.
Another factor to consider is the expected operating temperature of the aqueous cleaner. If higher temperatures are required, expect higher energy costs to heat the bath as well.
Aqueous cleaners are available in both liquid and powder form. While the liquid form is generally more convenient, you might consider using a powdered cleaner to reduce shipping costs.
Which Aqueous Parts Cleaner is Right for You?
Best Technology offers a full range of water-based degreasers and aqueous cleaning products to meet your industrial cleaning needs. The first step is to identify the metal or alloy that you will be cleaning. Below is a sample of our top-selling aqueous cleaners for stainless steel, aluminum and other metals. If you don’t find a match for your material on this chart, contact us for more information on other options that might be suitable for you.
Aqueous Cleaner Product Comparison
| Product Name | Best For | pH at Working Concentration | Operating Temperature Range | Physical Form |
| BestSolv-AC KleerKleen™ 4000 | Stainless steel | ~ 7.5 | Room temp or higher. Preferred range: 120 – 180 °F (49 – 82 °C) | Liquid |
| BestSolv-AC CHEMEON® Cleaner 1000 | Aluminum | 8.6 | 120 – 180 °F (49 – 82 °C) | Powder |
| BestSolv-AC CHEMEON® Cleaner 4000 | Aluminum alloys; brass and copper | 5.0 – 5.5 | 120 – 160 °F (48 – 71 °C) max for aluminum 110 – 200 °F (43 – 93 °C) for other metals | Liquid |
| BestSolv-AC Esma E589 General Purpose Cleaner | Stainless steel | 10.5 – 10.8 (at 100%) | Room temp to 200 °F (93 °C) | Liquid |
Common Applications for Aqueous Cleaners
- Pretreatment prior to other finishing processes such as passivation, electropolishing, anodizing or chromate conversion coating
- Precision cleaning of medical device, aerospace and automotive parts after machining operations
- Removal of buffing and lapping compounds
- Cleaning prior to welding, deburring, brazing, blasting or other post-process applications where surface cleanliness is critical
- General washing for maintenance, rework and/or remanufacturing
- Cleaning prior to assembly or final packaging
Aqueous Cleaning FAQs
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What’s the difference between solvent-based cleaning and aqueous cleaning?
There is an old saying when it comes to parts cleaning: “Like dissolves like”.
This comes from the world of chemistry, and is really quite a simple and useful phrase to remember. In chemistry molecules are described as being polar or non-polar. (Think north and south pole on the Earth) Polar molecules have a polarity that causes them to attract other molecules that have polarity, while non-polar molecules do not.
Water is a polar molecule. Oil is not. At the molecular level this is why “oil and water don’t mix”. Chemically they are dissimilar and cannot absorb each others molecules. By contrast salt IS polar; this is why you can dissolve salt in water.
So when should you use aqueous cleaning and when should you try cleaning with solvents? Solvent based cleaning systems (like Vapor Degreasers) are used when you need to clean true oils from your manufactured parts. Aqueous Cleaning Systems are used to clean water based materials from your parts.
Aqueous Parts Washers
Each aqueous cleaning solution is formulated for use with aqueous parts cleaning equipment. Formulations are specific to aqueous parts washer type, whether high flow and high pressure or ultrasonic cleaning. To learn more about various types of aqueous parts washers, visit these sections of our website:
Aqueous Cleaning Parts Washer
Aqueous Cleaners Price and Ordering
Please contact our chemical sales department for a quote on aqueous cleaners by clicking the “Get a Quote” button, or call 612-392-2414, ext. 2.