When an accident occurs involving a hazardous chemical road tanker with leaking toxic or flammable gas/liquid, what is the mandatory initial response for the driver and escort (押运员)?

1. Immediately trip the emergency shut-off valve if safe, extinguish all ignition sources, evacuate all personnel UPWIND (上风向), isolate the area, and call 119/122 stating the UN number and cargo name
2. Stand directly downwind in the vapor cloud to plug the leak with clothing
3. Use an open flame lighter to check if the leaking gas is flammable
4. Instruct passing motorists to drive faster through the chemical cloud to disperse it