Skip to main content

Chemical Analysis

Benzalkonium chloride is a commonly-used cationic surfactant and biocide. 

SGS Polymer Solutions provides testing of benzalkonium chloride (CAS No. 63449-41-2, also known as BZK, BKZ, and BAC) in accordance with the relevant USP Monographs. Benzalkonium chloride is used as a biocide, surfactant, and phase transfer agent for chemical reactions. The identity, purity, alkyl homolog distribution, and water content of benzalkonium chloride as a raw ingredient can be determined by SGS PSI.  SGS PSI can also determine the concentration of benzalkonium chloride in manufactured products.


Confirmation of the identity of benzalkonium chloride is accomplished by using a series of wet chemistry analytical methods in accordance with the applicable USP Monographs.

The alkyl homolog distribution of benzalkonium chloride in raw materials according to the USP monograph method is determined using an HPLC system with UV absorbance detection. Total benzalkonium chloride content is determined by titration according to the USP monograph.

The water content of benzalkonium chloride is determined by Karl Fischer titration.  During the Karl Fischer titration, water is consumed by a chemical reaction with iodide and sulfur dioxide in the presence of a base.

Sample Considerations

As a raw material, benzalkonium chloride is analyzed as a solid powder or as a solution typically in water.  A sample size of 10 grams is enough to conduct the benzalkonium chloride tests.

Sample sizes for manufactured products will vary depending on the expected benzalkonium chloride content and the specific testing methods that will be performed.

Our staff will guide the process to ensure the proper amount of a sample is submitted in order to achieve excellent data. Contact us with specific questions about your compendial USP testing of benzalkonium chloride needs.


SGS Polymer Solutions has conducted cGMP compliant benzalkonium chloride analysis in our FDA-registered laboratory for pharmaceutical clients.  We have also analyzed manufactured products for the presence of benzalkonium chloride.