The invention relates to bactericidal formulations that come into contact with human body, particularly wash formulations including liquid soaps, comprising perfume ingredients active against gram-negative bacteria. Such compositions contact the target site, for example the skin surface, only for a short time, usually not longer than 30 seconds. Therefore the antibacterial action has to be of the bactericidal type and rapid. Furthermore, the bactericidal activity has to be sufficiently high to ensure an effect even when applied to wet substrates that will dilute the bactericidal formulation.