Clear the air
If the fuel spill is found inside a closed room or building, immediately open all doors and windows to clear the air. Or simply just leave. If it happens outside, move on to the next step.
As soon as you spot fuel spill, go get yourself a bucket or any other container. Put the pail right where the fuel leaks so it can temporarily contain the fuel. If a bucket is not enough to contain the spill, try to block access to the drains. Soak up the spill with the right absorbents, the one that you can find in the First Response Spill Kit. If you don't have one ready, you can simply use the cat litter.
However, if you don't have the first response spill kit now and you haven't experienced the fuel leak yet, perhaps it's a good time to buy it now.
Stop the leak
Analyze the leak. Is it small? Can you stop it yourself without causing further damage? Do you have the means to do it? Our leak repair kits should come really handy at this point; for example the reusable drum leak patch shown above. Don't forget to wear protective gloves and safety glasses when you are dealing with fuel.
However, if the leak is too big to handle on your own, don't take any risk and call the right maintenance personal to help you fix it.
Dispose the absorbent materials correctly
Consult the environment and labor department to know the closest facility to dispose the used, fuel-contained absorbent materials. Do not throw them in the trash as this is highly flammable and can cause unwanted casualties. Do not flush fuel down the drain either.
Most importantly, be safe, try not to panic and teach the people you live and work with in case this happens when you are not present.