The present technology relates to biocidal compositions and methods thatcontain and utilize at least one biocidal agent, such as a quaternary ammoniumcompound, and at least one potentiator system. The potentiator system includesasurfactant, and a solvent such as propylene glycol n-propyl ether (PnP). Theresultantcombination has an enhanced biocidal efficacy. The present technology alsodisclosesa rapid screening assay for determining biocidal compositions with enhancedefficacy,e.g., a microbial contact kill time of 5 minutes or less. Further, the presenttechnologyprovides a method of determining biocidally effective concentrations ofbiocidalcompositions comprising at least one biocidal agent and at least onepotentiatorsystem.
