Very important features of benzalkonium salts are their bactericidal and antimicrobial properties. The antimicrobial activity depends on a changing length of the side n-alkyl chain. It is well known that the C12-homolog is most effective against yeast and fungi, the C14-homologue against gram-positive bacteria and C16-homolog against gram-negative bacteria . For these reasons they are widely used as preservatives for ophthalmic, nasal and parenteral products. They are also used as topical antiseptics and disinfectants for medical equipment . 

These compounds are not generally used as single components, but rather as mixtures composed of two or three benzalkonium members differing only in the length of the alkyl chains . Such mixtures are produced on a large-scale in industry. However, a targeted synthesis of pure individuals could be of interest because of the above-mentioned specificity of each salt against different pathogens.