Upon arriving at a scene with an overturned tanker truck leaking a clear liquid, what is your immediate action?

Requesting fire department assistance when encountering an overturned tanker truck leaking a clear liquid is the most appropriate immediate action due to safety and hazard assessment considerations. The fire department has specialized training and resources to manage hazardous materials incidents, including determining the nature of the liquid, mitigating potential dangers, and ensuring the safety of all individuals at the scene.

In situations involving hazardous materials, like a leaking tanker, it is critical to have trained personnel capable of correctly identifying the substance and determining appropriate containment and cleanup measures. By calling for assistance as the first action, you ensure that expert resources are on their way, which is essential for protecting both responders and the public from potential chemical exposure or fire hazards.

Other options may involve addressing the incident but do not prioritize safety or necessary protocols. Ensuring the ambulance is properly positioned (downwind and downhill) can be critical, but this action should follow the establishment of safety measures and verification of hazardous conditions. Approaching the tanker directly to identify the liquid could expose you to unknown risks, and attempting to remove the driver without assessing the situation poses further danger. Hence, requesting assistance first establishes a safer response strategy.