What is the potential risk?

Fuelling boats with gasoline can create a risk of explosion, leading to loss of life, injury, and significant property and environmental damage. An explosion requires four elements: fuel, ignition source, oxygen, and containment. All four elements can be present when refuelling boats.

Gasoline evaporates into a flammable vapour that’s denser than air. This vapour can accumulate in hatches, bilges, the engine compartment, and cabins near the boat’s fuelling area. If the boat is not properly ventilated to remove this flammable vapour, it can mix with air, and may reach a ratio that will result in an explosion if it contacts a nearby ignition source.

Proximity to other fuel sources such as the fuelling dock and other boats may result in the fire spreading and additional explosions. With increased activity on the water during warmer weather, as well as greater demand on fuelling docks, the potential for explosions also increases.

Who may be at risk?

Workers at risk include fuel dock attendants, tour operators, fishing and dive guides, and any other worker involved in or working near boat refuelling. The boating public is also at risk.

How can I reduce the risk in my workplace?

Develop and support procedures to be followed every time a boat is fuelled, and ensure your workers are trained in these procedures. The following procedures are recommended by Transport Canada and Maritime Safety Victoria (Australia).

Before fuelling:

• Ensure the boat is secured to the fuelling dock and that the engine has been turned off.
• Ensure passengers step off the boat. This will help keep the boat stable and reduce the likelihood of spills.
• Make sure that no one is smoking in the area and that all ignition sources such as stoves and pilot lights are extinguished. All electrical equipment that could throw a spark must also be turned off — including cellphones, electric motors, batteries and power sources, and portable radios.
• Ensure all doors, windows, and hatches where gasoline vapours could enter are closed.

During fuelling:

• Do not start the fuelling dispenser until the outlet nozzle is inserted in the tank. Hold the nozzle open by hand only — do not lock or jam the trigger open.
• Keep the outlet nozzle touching the filler neck during refuelling to prevent static sparks.
• Don’t try to top up or overfill the tank — leave room for gas to expand and avoid overflow.
• Have a cloth ready to catch any spills.
• Ensure that all air vents to the gas tank are open, and use your hand if possible to check for air escaping from the vent. When the tank is nearly full, you will feel an increase in airflow, which is the signal to stop filling.

After fuelling:

• Immediately replace the gas cap tightly. Wipe up any spills or leakage, and remove and safely dispose of any gas-soaked materials.
• Open all the doors, windows, and hatches to allow air to circulate through the boat.
• Turn on the blower to ventilate the tank and engine compartments. Be sure to run the blower for four full minutes after fuelling — or more if that’s the manufacturer’s recommendation.
• When you are completely satisfied the boat is free of vapours (gas detectors can be helpful here), start the engine and allow passengers back onboard.
• If the engine is hard to start after refuelling, don’t keep trying. This can be a sign of gasoline vapours in the engine compartment.

Communicate with the public, who may not be aware of the risks. The following are some examples:

• Develop clearly defined procedures for fuelling specific to your location. Post this information at the fuelling dock and wherever boaters are waiting to be fuelled.
• If you have radios to communicate with boaters, use this system to let boaters know about fuelling procedures.
• Emphasize the importance of the four-minute blower period to allow vapours to dissipate. Create a system to help boaters time the blower for the recommended four minutes (e.g., countdown clock, key control, red and green lights).
• Have a system for reporting and managing boater non-compliance.

Where can I find more information?

• Part 5 of the Occupational Health and Safety Regulation
• Boat Fuelling Requirements & Safety (BOATERexam.com)
• Refuelling (Transport Canada)
• Refuelling (Maritime Safety Victoria — Australia)

Learn more about managing risk in your workplace.