What potential risk is associated with connecting a hose line to an outlet without a flow restrictor or pressure-reducing valve?

Connecting a hose line to an outlet without a flow restrictor or pressure-reducing valve can lead to the risk of rupturing the hose. This occurs because water is delivered at a high pressure, which the hose may not be designed to withstand without proper regulation. The pressure exceeds the tolerable limits of the hose material, making it susceptible to failures such as ruptures or blowouts, which can lead to dangerous situations for the firefighter and increase the risk of injury or damage.

While other factors like lowering water pressure and increasing flow resistance might be relevant in certain contexts, in this particular situation, the immediate concern is the hose's ability to sustain the pressure. Additionally, improving nozzle handling is not relevant to the potential risk associated with uncontrolled pressure from the outlet. The correct focus is on the potential mechanical failure of the hose due to excessively high pressure when a flow restrictor or pressure-reducing valve is not in place.