The progressive statistics of forest fires in the world makes them a global problem for humankind; therefore, the issue of controlling such natural disasters is extremely urgent. This paper describes the application of fine-dispersed alumina nanoparticles in firefighting. Nanocolloids based on aluminum hydroxide are proposed as the extinguishing compositions for two purpose: fire prevention and fire suppression with alumina barrier formation. Aluminum sulfate and various hydrolyzing agents (ammonia solution or sodium bicarbonate) were used to produce hydrosols. A ceramic coating based on the gamma phase of aluminum oxide with a specific surface area up to 150 m2/g is formed as a result of heat treatment during combustion. Creation of this barrier prevents oxygen access and removes heat excess simultaneously. The preparation of low-cost fine-dispersed nanoparticles of inorganic oxides is possible directly at the fire location by the firefighters themselves. In addition, obtained ceramic foam performs stable, environmentally friendly properties and prevents re-ignition.