What does smoldering primarily produce?

Smoldering primarily produces the same byproducts as under-ventilated combustion, but it is characterized by the production of carbon monoxide (CO) in significant quantities. This is because smoldering combustion occurs at lower temperatures and with insufficient oxygen, leading to incomplete combustion of the fuel. As a result, rather than producing primarily carbon dioxide and water vapor—typical of complete combustion—smoldering leads to a higher ratio of carbon monoxide as a byproduct, along with various unburned hydrocarbons and particulate matter.

This process is particularly relevant in environments with limited airflow, where fires can burn slowly and produce toxic gases like carbon monoxide, which can be hazardous to health. The production of carbon monoxide is a key indicator of smoldering fires, distinguishing them from fully ventilated fire scenarios. In contrast, other options either reflect the outputs of complete combustion or do not accurately represent the typical byproducts associated with smoldering combustion. This understanding of the byproducts of smoldering is crucial in both fire behavior and fire prevention strategies.