Liquid fuel poses several types of hazards such as poisonousness, corrosiveness, and flammability. Gasoline is the most dangerous of these fuels, although these precautions also apply to diesel fuel. Fuel safety precautions are generally standard for all vehicles and may be categorized into electrical, exposure, leaking and storage precautions. Fire prevention is also an important consideration when we perform maintenance on a fuel system.


Gasoline vapor is extremely flammable and can be ignited with a tiny spark. It is essential that we prevent fuel vapor or spray from coming into contact with any spark or flame. Disconnect the negative battery cable before beginning any test or repair procedure on a vehicle unless that procedure requires electrical power from the battery.


All fuels are corrosive to our skin and poisonous to breathe or swallow. Relieve the pressure in the fuel lines before beginning any procedure on the fuel system, including the fuel lines, fuel pump, and fuel injector. It is especially important to prevent fuel from coming into contact with our skin, eyes, and mouth when working on a vehicle with a high-pressure fuel system. The fuel pressure in these vehicles can be high enough to make the fuel penetrate our skin.


Leaks can make the risk of fire and exposure to fuel much more likely. Wrap a shop towel around the fitting on a fuel line before you loosen the fitting to absorb any leaking fuel. Wipe up any fuel leaks as quickly as possible, especially from engine surfaces. These surfaces can become hot enough to ignite spilled fuel when the car is running.

Dispose of all fuel-soaked cloth in a suitable container.

Loosen and tighten fuel-line fittings with two wrenches. This will allow us to hold the fuel line in place with one wrench while loosening or tightening the fitting with the other wrench, thus minimizing the stress on the fuel line. It is also important to inspect the O-rings for the fuel system whenever we remove them. Replace worn O-rings with new ones. Do not replace fuel pipes with fuel hoses or equivalent components.


Procedures such as relieving fuel pressure or draining the fuel tank often require us to store excess fuel temporarily and replace it after the procedure is complete. Fuel must be kept in a container that is approved by Underwriters Laboratories for the storage of fuel and will be so labeled. This generally means the container is airtight and will not react chemically with the fuel. UL-approved fuel containers may be made of metal or plastic.


PreventionFuel fires cannot be extinguished with water, so we must keep a Class B fire extinguisher in our work area. This type of fire extinguisher contains dry chemicals that will deprive a fire of oxygen.