What must occur for combustion to take place?

For combustion to take place, there must be an adequate amount of both oxygen and fuel available. This combination is essential for the chemical reaction that produces fire. Combustion is a process that requires a specific mix of reactants to sustain a flame; without sufficient oxygen, flames cannot ignite or continue burning. Likewise, without an appropriate fuel, there is nothing for the fire to consume, which means combustion cannot occur.

The presence of fire suppression systems, high pressures and temperatures, and the absence of moisture are related factors, but they do not directly facilitate combustion. Fire suppression systems are designed to prevent or extinguish flames, while high pressures and temperatures may affect the combustion process but are not essential to its initiation. Additionally, moisture tends to inhibit combustion by absorbing heat and cooling the fire, but dryness alone does not guarantee that combustion will occur.