Gasoline Tanker Rupture Near a Creek and School
A 5,000-gallon MC-307 tanker carrying 4,200 gallons of gasoline strikes a guardrail on a two-lane road. The rear compartment is ruptured near the bottom, and gasoline is pooling in a shallow ditch that drains toward a creek 150 feet away. A visible vapor cloud is moving with a light wind toward a school about 0.4 mile downwind. There is no fire. The driver is uninjured but shaken; the engine is still running, and the battery switch is on. The shipping papers are in the cab. A bystander is walking toward the tanker with a cigarette lighter to 'see if it's diesel.' You have a fire extinguisher and a cell phone. It is 14:10, temperature 80°F, clear, and traffic is stopping.
1. List your first five actions in order and explain the priority.
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- Keep people away: shout to the bystander to stop and move upwind; no smoking, no lighter, no phone near the vapor.
- Shut off the engine and battery switch if you can do it without crossing the leak or vapor; this removes ignition sources.
- Move yourself and others upwind and uphill, away from the ditch, and call 911.
- Identify the product from the shipping papers and placards (gasoline, UN1203) and report the leak, fire risk, creek, and school.
- Isolate the area and keep traffic back; do not try to plug a 4,200-gal gasoline leak with a hand tool.
Priority is life safety and ignition control first, notification second, containment only by trained responders.
2. What initial isolation and protective action distances apply, and how do the creek and school change your notification?
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For gasoline (UN1203), the ERG guide calls for an initial isolation of at least 150 feet in all directions and a protective action distance of about 0.5 mile downwind for a small spill; a large tanker release can require more, so confirm with the ERG and responders.
The school at 0.4 mile downwind is inside that protective action distance: tell 911 to notify the school to shelter or evacuate, and give the wind direction. The ditch draining to the creek 150 feet away means the spill can reach water; notify the fire department and environmental agency, and do not flush it. Keep people out of the ditch and away from low ground where vapors collect.
3. If the gasoline ignites while you are retreating, what should you do and not do?
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Continue moving upwind and away; call 911 and tell them the tanker is on fire with gasoline. Do not attempt to fight a large flammable-liquid fire with a hand extinguisher; only use one on a small incipient fire if you have a clear escape path and training.
Do not extinguish the flame unless the leak can be stopped, because unburned vapor can collect and explode. Do not re-enter the area. From a safe distance, tell responders which compartment ruptured and where the shutoffs are. Let firefighters use foam and cooling water; your job is isolation and information.