Which hazard is of particular concern with the use of gasoline-powered portable pumps?

Carbon monoxide is a particularly concerning hazard when using gasoline-powered portable pumps because these engines emit this toxic gas as a byproduct of combustion. When the pump is in operation, especially in enclosed or poorly ventilated spaces, the accumulation of carbon monoxide can reach dangerous levels, posing significant health risks, including headaches, dizziness, confusion, and even loss of consciousness.

Understanding the specific risks associated with gasoline-powered engines is critical for firefighter safety and operational effectiveness. Since carbon monoxide is colorless and odorless, it can go unnoticed until symptoms arise, making it even more dangerous. Proper ventilation and monitoring for carbon monoxide levels are essential preventive measures when using such equipment.

The other options, while they do represent potential hazards, do not capture the unique dangers associated with gasoline engines in the same way carbon monoxide does. Flammable liquids, overheating, and electrical hazards may also be relevant but are not as directly linked to the immediate emissions produced by running a gasoline-powered pump.