COUNTERFOG will be a new, rapid response system for collapsing all kinds of dispersed agents (smoke, fog, spores, etc.) by using a fog made of a solution that could eventually contain any kind of neutralizing component. It will be a permanent installation in large public buildings like railway stations but also a portable COUNTERFOG for use outdoors, used to counteract a CBRN attack in its earliest stages, greatly reducing the number of potential fatalities. In fact, COUNTERFOG will use the same “weapon” as a CBRN attack: a dispersed state with a large surface/volume ratio. It will penetrate all the intricate holes CBRN agents are able to infiltrate. As it needs a minimum quantity of decontaminant, it is intrinsically an environmental-friendly and electric-compatible system. It would have three benefits: Firstly, to neutralize and collapse the CBRN cloud, secondly, to rapidly decontaminate all the affected people in that area, and finally, to rapidly decontaminate any equipment and the facility itself.Because of the large-scale fogging capacity of up to three components, choice of pressures and capability to simultaneously emulsify liquids and disperse solid particles and an enormous surface/volume ratio, it will be possible to counteract a CBRN cloud in large, open areas. Nozzle, sensor and solid mesoporous particles will be technological keys.A Fog Dynamic Laboratory will be designed, built and used in the project to test the ability such a system has to condense different kinds of smokes, clouds or fogs and its ability to simultaneously neutralize different kinds of CBRN agents and combined incidents (fire & CBRN). Full scale tests will be also performed. Eventually, the real applicability, side effects and compatibility with conventional fire protection facilities will also investigated, a detailed marketing plan prepared and a diffusion campaign implemented. Furthermore, a spin-off company will be set up in order to exploit the results most effectively.