For those persons involved in fire prevention, the fire triangle is the starting point for any approach to protection or prevention. However, barely two decades ago, a fire was tackled from the perspective of limiting the probability of ignition, separating the fuel from the comburent through dust, foams, gas or water or saturating the rooms with inert gases.
There is actually another approach to prevention: reducing oxygen below a threshold that does not allow combustion to sustain itself. The theory is simple, and was known since Lavoisier, at the end of the 18th century, discovered the role of oxygen in combustion processes. However, the development required not only theoretical concepts but technologies, materials and management techniques that have only recently become available.
In particular it was in Germany, in the 2000s, that the ignition thresholds for the different materials finally began to be identified. A substantial difference between caution and prevention is that the second must act continuously. Maintaining a constant hypoxic atmosphere in an environment, i.e. one in which oxygen does not exceed 15% of the mixture, requires many aspects to be addressed simultaneously.
Firstly, it is necessary to have devices that act on the gases present, segregating some and increasing the concentration of others; in turn these systems must be guided by analysis and continuous control of the air parameters. But this is not enough; building waterproofing techniques are required for the premises together with air exchange systems that allow "perimeter control".