Microbial infection of surfaces and the formation of biofilms is a pervasive problem that appears in diverse fields from medical implants to corrosion of marine structures. We show here, for the first time, the multifunctional inhibitory effects of an environmentally friendly organic salt, cetrimonium nalidixate, a dual active compound based on concepts emerging from the active ionic liquids field. This salt when incorporated into a polyurethane coating leads to complete inhibition of microbiologically influenced corrosion in the presence of several bacteria strains commonly found in marine environments.