What is the flammability range of carbon monoxide (CO)?

The flammability range of carbon monoxide (CO) is between 12.5% and 74%. This range is significant because it indicates the concentration of carbon monoxide in air that can ignite and sustain combustion. At concentrations below 12.5%, the mixture is too lean to support combustion, while concentrations above 74% can also be non-flammable due to insufficient oxygen necessary for burning.

Understanding this range is essential for fire service professionals, as it informs strategies for ventilation, suppression, and rescue operations in environments where carbon monoxide is present. Recognizing the properties of CO and its flammability limits helps firefighters assess the risks related to its accumulation and potential ignition.