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 [CMIM][Cl] ionic liquid (IL) and its formulation in ethanol for killing and removing bacteria from different environmental surfaces. 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 [CMIM][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% [CMIM][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 disinfection activities of [CMIM][Cl] have increased markedly when prepared in 70% ethanol, suggesting synergistic activity. A formulation comprising of 0.01% [CMIM][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.