Identify a toxin produced from combustion in an aircraft fire.

Carbon monoxide is a common and dangerous toxin produced during combustion, especially in aircraft fires. When materials such as fuels, plastics, and other organic substances burn, the combustion process can create incomplete oxidation reactions. This results in the formation of carbon monoxide, a colorless, odorless gas that can be highly toxic to humans. Exposure to carbon monoxide can lead to serious health effects, including headaches, dizziness, confusion, and can even be fatal in high concentrations.

The other substances mentioned are either not toxins or are not typically considered harmful in the context of combustion in an aircraft fire. Oxygen, for instance, is crucial for combustion but is not a byproduct of combustion itself. Carbon dioxide, while produced during combustion, is less immediately toxic compared to carbon monoxide, although elevated levels can cause suffocation in confined spaces. Nitrogen gas is a major component of the atmosphere and is generally inert, meaning it does not participate in combustion processes or pose a health risk in the context of fire. Thus, carbon monoxide stands out as a significant and harmful byproduct of aircraft fires.