Assessment of alkylimidazolium chloride ionic liquid formulations for cleaning and disinfection of environmental surfaces

Background: Surface disinfection is fundamental to good environmental hygiene and preventing infections. Development of newer formulations that can effectively kill and remove microorganisms from the surfaces is desired. Methods: Here, we assessed the efficacy of 1-hexadecyl-3-methylimidazolium chloride [C16MIM][Cl] ionic liquid (IL) and its formulation in ethanol for killing and removing bacteria from different environmental sur-faces. Efficacy of IL and its formulation was determined on known monospecies bacterial cultures and unknown multispecies bacterial cultures on environmental surfaces. Result: The surface disinfection efficacy of [C16MIM][Cl] was concentration dependent and achieved 41 to 100% reduction in total viable bacterial counts of Gram positive and Gram negative bacteria at varied concentrations. The treatment of wooden surface with 0.1% [C16MIM][Cl] caused 98% reduction in bacterial load within 20 s contact time as against mere 45% reduction (20 s) with 70% ethanol. Antibacterial and surface dis-infection activities of [C16MIM][Cl] have increased markedly when prepared in 70% ethanol, suggesting syn-ergistic activity. A formulation comprising of 0.01% [C16MIM][Cl] in 70% ethanol showed effective surface disinfection and achieved 95% to 98% reduction in bacterial load on different surfaces.Conclusion: Ionic liquids are potent candidates for disinfection of environmental surfaces. (C) 2021 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Automated summary

This study found that the 1-hexadecyl-3-methylimidazolium chloride ionic liquid and its ethanol formulation have high efficacy and potential for killing and removing bacteria from different environmental surfaces. The concentration of the ionic liquid affects its surface disinfection efficacy, and the ethanol formulation enhances its antibacterial and surface disinfection activities.