Why must oxygen tanks be kept away from flammable materials?

Oxygen is essential for combustion, meaning it plays a critical role in any fire. When oxygen is present in higher concentrations, it can significantly increase the flammability of materials around it. This creates a heightened fire risk because even materials that normally wouldn't ignite can become combustible in an oxygen-rich environment. Keeping oxygen tanks away from flammable materials minimizes the risk of fire or explosion, protecting both personnel and property.

The other options do not accurately reflect the relationship between oxygen and fire safety. For instance, while oxygen can be considered cheap, that fact does not influence its flammability. Additionally, oxygen is not classified as a toxic substance in typical conditions, and rather than lowering temperatures, it can actually facilitate higher combustion temperatures, further increasing fire danger. These misunderstandings emphasize why it is crucial to recognize oxygen's role in supporting combustion.