Build-up of scale residues in bathrooms, toilets and coffee machines is a well-known problem. This scale or lime can be removed by means of an acid. PURAC is an efficient and cost-effective descaler for this purpose. Besides its mildness, neutral odor and hard-water salt solubility, it will, for example, remove scale twice as effectively as citric acid.


A good way to predict the effectiveness of an acid is by means of the so-called marble block test method. This test is a good method to predict its performance under practical conditions. The links below provide information on the descaling performance of PURAC in several conditions.

·                     Descaling performance at room temperature

·                     Descaling at elevated temperatures

·                     Descaling in combination with surfactants

Descaling performance at room temperature

The graph below shows the descaling performance of PURAC as well as some other organic acids at various concentrations. To test the descaling performance, the marble block test method was used. In this test, a well-defined Carrara marble block is submerged for 15 minutes in a test solution. The weight is measured before and after.

The graph clearly shows the effectiveness of PURAC as a descaler. For example, it is twice as effective as citric acid, and even more effective compared to glycolic acid. Although some other organic acids, like acetic and formic acids, are good descalers, they have the disadvantage of an irritating smell and are more corrosive towards metal surfaces.

PURAC, L(+)-lactic acid, is a good choice for making your formulation efficient and odorless yet cost-effective.

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Descaling at elevated temperatures

Descaling performance at elevated temperatures is an important item for industrial cleaning and coffee machine cleaners. The combination of its good descaling performance in combination with its mild behavior on metals makes PURAC the acid of choice when it comes to cleaning at elevated temperatures. The graph shows the descaling performance of four organic acids with a 5% concentration at several temperatures. PURAC outperforms all of the others.



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Descaling in combination with surfactants

Compatibility of an acid with surfactants is essential for making a proper detergent formulation. PURAC is compatible with all commonly used surfactants in the industry. The graph below shows the descaling performance of 10% acid solution neutralized to pH 3 in combination with several surfactants at a concentration of 2%.

As can be seen, the descaling performance of PURAC is not noticeably affected by the surfactant, and the superior descaling performance over citric acid remains.



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