What chemical component is absolutely required for terrestrial fire or combustion aboard the ISS?

Answer

An oxidizer, typically molecular oxygen (O₂)

Terrestrial fire, or combustion, is a chemical reaction that absolutely requires an oxidizer, which is usually the molecular oxygen found in the Earth's atmosphere or carried within a spacecraft's habitat.

What chemical component is absolutely required for terrestrial fire or combustion aboard the ISS?
physicsSpacecombustionoxygenfire