Polish version

Benzalkonium lactates

Benzalkonium L-lactate and benzalkonium D,L-lactate are ionic liquids with excellent biocidal properties. They contain an expanded ammonium cation, displaying biocidal properties and a mandelate anion, non-toxic and pharmaceutically acceptable. Biological activity of benzalkonium lactates against a number of microorganisms is from several to several dozen times bigger than active substances widely used in preparations available on the domestic market. Their biocidal action is most effective against the following microorganisms: Staphylococcus epidermidis, Moraxella catarhalis, Bacillus subtilis, Rhodotorula rubra.

They are food deterrents against insects e.g. khapra beetle Trogoderma granarium (larva), i.e. chemical substances, which act on taste organs of insects, reducing their appetite, up to total stopping of foraging, what eventually brings them to death.

They belong to the group of cationic surface active compounds. They display also electrostatic properties.

Benzalkonium L-lactate and benzalkonium D,L-lactate can be ingredients of:

  • biocidal preparations,
  • insecticidal preparations,
  • and disinfecting/washing preparations.


R1 = C12H25 (60 %), R1 = C14H29 (40 %)

Benzalkonium lactates are thick liquids, soluble in water, acetone and ethanol, thermally stable, with decomposition temperature > 180 °C.

They have no toxic effect on warm-blooded organisms (toxicity class IV).

A brief description of the process

Benzalkonium lactates are obtained in reaction between benzalkonium chloride and a potassium salt of L-lactic (or D,L-lactic) acid, in aqueous environment at temperature 40 °C. The product is separated by distilling off water under reduced pressure and filtering off the by-product – potassium chloride.

In order to remove water it is necessary additional drying of the product at elevated temperature and under reduced pressure.

Advantages of the technology offered

The technology is simple, low-waste and substrates are cheap. The environment of the reaction is water and the by-product is potassium chloride.

The reaction yield is high.


The apparatus set comprises a glass reactor with bottom draining valve, equipped with a high-speed mechanical stirrer, a thermometer and a dephlegmator (which can be exchanged for a distillation set) and a heating-cooling jacket, allowing to heat up and cool down the contents.

Auxiliary equipment comprises:

  • thermostat,
  • membrane vacuum pump,
  • vacuum evaporator (to distillate off water from the post-reaction mixture and for final drying of the product).

Advancement of proceedings

There has been compiled documentation concerning physicochemical properties and analytic methods have been developed. Acute toxicity studies have been performed.

There have been performed trials to obtain benzalkonium lactates on the scale of 1.5 kg of the product.


Pat. PL 207 844 (2010) „New quaternary ammonium salts of lactic acid and a method to obtain new quaternary ammonium salts of lactic acid”.

Pat. PL 209 390 (2010) „Application of benzalkonium lactate as a food deterrent”.

Pat. PL 208 416 (2010) „Application of benzalkonium lactate in washing and disinfection”.

Market competitiveness

New ionic liquids are novel compounds with fungicidal and bactericidal properties. The effect of benzalkonium lactates is against some microorganisms many times more effective than commonly used benzalkonium chloride, so they can be applied in preparations in low concentrations.

Type of expected cooperation

Cooperation in compiling registration documentation, deployment and launching production of the preparation.


Anna Wiśniewska, M.Sc., Chem. Eng.

phone: + 48 22 568 21 93