What is the correct emergency response for the driver and escort if a leak, fire, or toxic release occurs on a hazardous chemicals vehicle on an expressway?

1. Park on the hard shoulder, shut off engine, place warning triangle, evacuate immediately to an upwind and uphill location, warn nearby motorists, and dial 119/122 stating the exact UN number and chemical name
2. Stay inside the cab with the air conditioning running on maximum recirculation
3. Attempt to extinguish a massive toxic gas leak using an ordinary wet cotton towel
4. Quickly dump the leaking chemical drums into the roadside drainage ditch and drive away