APC and Degreasers
This type of product is dominated by water based products although heavy degreasing can require solvent based products to avoid the need for excessive levels of alkalinity.
Water based products
These are most often blends of surfactants, sequestrants and pH modifiers designed for the removal of dirt and grease. The majority of products are alkaline in order that they can react with greasy and acidic soiling, which represents the majority of soils encountered. A notable exception to this is construction residues such as cement dust – this is strongly alkaline itself and will not be effectively removed by most APCs and degreasers. Depending upon the precise use, the blends will vary with the most significant variation being the pH and pH provider. As alluded to previously, this can be broken into caustic and non-caustic. The latter should be favoured as a truly multipurpose product since it will not product staining of sensitive finished. However, caustic based products will give notable better value for money due to the potential for higher concentrations so this should be balanced with the need for product safety.
Solvent based products
With heavy grease and oil deposits, a water based product may simply be incapable of dissolving and removing all the soiling, even when highly concentrated. In this instance it is possible to dispense with highly alkaline products and instead use products which are based on non-polar solvents. Because these solvents are chemically similar to oils and greases, they can dissolve them gently, much in the same way sugar dissolves in hot tea. These products are necessarily more expensive and cannot be diluted but will be much more effective, require less manual assistance and require less time to remove heavy deposits. Typically solvent based degreasers will be used in workshops or similar for use around engines etc.