This achievement has meant a great advance for human health. It is based on the biocidal and bacteriostatic effect of the SONOXIDE® system, used in refrigeration towers of factory buildings and installations that are prone to be the focus for the proliferation of Legionnaires' disease. In order to validate the system, the team of INASMET-Tecnalia experts designed a refrigeration tower simulation within a biologically-isolated laboratory (P2 level). A wide range of trials were carried out in this isolated and secure system in order to determine the efficacy thereof. Regarding the technology developed, it consists of a system based on low-intensity, high-frequency ultrasounds which, together with the introduction of micro-bubbles of air, produce an effect of photo-sonoluminiscence. The concentration of ultrasounds by constructive interference generates a pressure front that produces a decompression of the gases dissolved in the water. This wave front produces a luminous plasma around the bubbles, as well as high pressure and temperatures. These pressures and temperatures have two effects: on the one hand, they eliminate the circulating bacteria and, on the other, they generate an oxidative stress that is transmitted throughout the water refrigeration system. This stress, together with the continuous loss of circulating bacteria throughout the system, reduces the formation of biofilm even at extremely low levels - and maintains this to such an extent that the fixing of legionella bacteria or any other micro-organisms needing biofilm in order to grow in the system, is impeded.