Gasoline Spill Over a Service Pit
At 09:40, a technician is draining a 55 L fuel tank on a 2016 sedan over the workshop's 1.2 m deep service pit. The drain hose slips; about 14 L of gasoline spills onto the pit floor and spreads toward a floor drain. A portable kerosene heater is operating 4 m away because the bay doors are open. Three technicians are in the bay; one wears nitrile gloves and safety glasses but no respirator. The spill kit contains clay absorbent, two absorbent socks, a polyethylene salvage drum with lid, and a spark-free scoop. The floor drain discharges through an oil-water separator that was last serviced 14 months ago. The shop's emergency plan says evacuate and call the safety officer, but the shift supervisor is off-site. The apprentice asks whether to wash the fuel into the drain with water and then mop up. Customers are waiting; the service manager wants the bay back in 45 minutes.
1. State the immediate actions in priority order and explain the reason for each. Directly address the apprentice's proposal to wash the fuel into the drain.
Read the worked answer
- Stop the transfer and remove ignition sources first. Shut off the kerosene heater and any non-explosion-proof equipment. Gasoline has a very low flash point, and its vapor is heavier than air, so it will collect in the 1.2 m pit. The heater 4 m away is a credible ignition source even though the liquid is not touching it.
- Evacuate nonessential people and ventilate. Open bay doors only if this does not spread vapor toward the heater or other ignition sources. Use an explosion-proof fan; do not switch ordinary lights or use a shop vacuum, because brushes and switches can spark.
- Use the right PPE. Nitrile gloves and safety glasses are not adequate for a 14 L gasoline spill with unknown vapor concentration. Use fuel-resistant gloves, splash goggles plus face shield, and do not rely on an organic-vapor cartridge respirator if concentration or oxygen is unknown; evacuate and call the safety officer/emergency responders.
- Contain before recover. Place absorbent socks around the floor drain to keep liquid out of the separator. Work from the outside of the spill inward with clay absorbent and a spark-free scoop. Do not wash the fuel into the drain. Water spreads gasoline over a larger area, increases vapor generation, and can carry fuel through the oil-water separator into the drain system. The separator is overdue for service, so it may not stop the fuel.
- Recover and re-enter only after monitoring. Place absorbed material in the labeled salvage drum. Do not allow re-entry until the area is ventilated and a combustible-gas meter shows a safe reading.
2. Describe how to recover and dispose of the free fuel, absorbent, and contaminated PPE, and what records should be completed.
Read the worked answer
Free liquid should be picked up with a hand pump rated for flammable liquids or with absorbent, not with a shop vacuum. Use non-sparking tools and bond/ground metal containers if bulk transfer is necessary. Place the recovered fuel, used absorbent, contaminated rags, and disposable PPE in the polyethylene salvage drum with a tight lid. Label the drum with the date, contents (waste gasoline/absorbent), hazard class, and generator information.
The material is hazardous waste and must not go into general refuse or be poured into the drain. Arrange pickup by a licensed hazardous-waste contractor and retain the manifest. Complete an incident report with the time, quantity spilled, cause, personnel involved, notifications, corrective actions, and photos if permitted. Notify the safety officer and, if any fuel reached the drain, the municipal sewer authority or environmental regulator as required by the site permit. Record the separator inspection and any contaminated absorbent removed from it. Also record employee PPE use and any exposure symptoms. These records protect the workers and show that the shop followed its emergency plan.
3. Identify at least three root causes of this incident and propose specific corrective actions to prevent recurrence.
Read the worked answer
Root causes include: (1) the fuel transfer was started without a pre-task plan or permit, and the shift supervisor was off-site; (2) an open kerosene heater was allowed in a bay where fuel was being drained; (3) the technician's PPE was chosen for splashes, not for a flammable-liquid spill; and (4) the floor drain had no secondary containment and the separator was overdue for service.
Corrective actions should be specific: require a written permit for fuel-system work, including a drain-pan capacity at least 1.5 times the fuel volume, bonding/grounding, and a dedicated ignition-source check. Prohibit portable heaters in service bays; use fixed, approved shop heating. Stock the spill kit with a flammable-liquid pump, compatible gloves, and an explosive-gas meter, and train all technicians to use it in a drill. Install a drain seal or absorbent sock station at each floor drain and service the oil-water separator on a scheduled basis. Finally, assign a competent supervisor or alternate for every shift and audit fuel transfers monthly.