Engine off, nothing lit within 25 feet

Gasoline gives off vapor that will burn at temperatures far below zero. On a still summer day the vapor from an open fill rolls along the ground farther than your hose reaches.

The points

• No one smokes or carries a lit cigarette, cigar or pipe on or within 25 feet of a truck carrying gasoline or other Class 3 fuel. That includes an empty tanker that hauled it placarded. An empty tank is full of vapor.
• Class 3 fuel is not loaded into or unloaded from a cargo tank with the engine running, unless the engine drives the pump. A diesel engine may run when it is 10 °F or colder outside.
• The handbrake is set and every other reasonable step is taken so the truck cannot move during the transfer. Chocks cost nothing and a torn fitting costs a spill.
• Keep fire away means more than cigarettes. A burn barrel, a welder in the next bay, a space heater in the shop door, a running generator - look around before you open a valve.
• When you fuel your own truck, the engine is off unless it is needed to fuel, the nozzle stays in contact with the fill pipe, and nobody smokes or has an open flame nearby.

Why it goes wrong

Gasoline gives off burnable vapor at every temperature you will ever work in. The vapor is heavier than air, so it rolls along the ground, into ditches, under trucks and down drains toward whatever is lit. You often cannot see it except as a shimmer. Diesel is harder to light as a puddle, but diesel mist or diesel on a hot exhaust part burns, and a compartment that last held gasoline is still a gasoline compartment.

49 CFR 397.13 says no person may smoke or carry a lighted cigarette, cigar or pipe on or within 25 feet of a motor vehicle carrying Class 3 materials, or of an empty tank vehicle that hauled them placarded. 177.834(c) and (d) add that smoking on or about the vehicle during loading or unloading is forbidden, and that extreme care is taken to keep fire away and keep people nearby from smoking, lighting matches or carrying any flame.

177.837(a) says Class 3 material is not loaded into or unloaded from a cargo tank while the engine runs, unless the engine is used to run a pump. Many tank wagons drive the pump off a PTO, so the engine runs for that reason and that reason alone. Idling for the heater or the radio while you gravity-drop is not covered. The cold-weather exception is narrow: a diesel engine, at or below 10 °F.

177.834(e) says no hazardous material is loaded or unloaded unless the handbrake is securely set and all other reasonable precautions are taken to prevent motion. A truck that creeps a foot with the hose on can tear a fitting off a tank or pull a hose out of a fill pipe at full flow. Set the brake, chock on a grade, and if anyone else needs to move a vehicle near you, they wait.

When you fuel your own truck, 49 CFR 392.50 applies. No fueling with the engine running unless it has to run to fuel, no smoking or open flame in the vicinity, the nozzle stays in continuous contact with the fill pipe, and you do not let anyone else do something likely to start a fire. A nozzle that is not touching the fill pipe is a gap where static can jump.

Look at the customer's site the way a fire would. A shop door open with a heater running, a welder on a trailer, a farm burn pile, a generator running near the tank vent, a pickup idling next to the fill. You cannot control their whole yard, but you can ask for it to stop before you open a valve, and you can refuse the drop until it does. Write down what you asked for and when.

Questions for the crew

1. At each stop today, what is the nearest flame or spark source - burn barrel, welder, heater, generator?
2. Does any truck today run its pump off the engine, and does everyone know that is the reason it runs?
3. Who at the customer's site needs to hear that the 25 feet applies to them too?

To close

Today the engine is off unless it runs the pump, the brake is set, and nothing lit comes within 25 feet.