Gasoline
What can I do with old gasoline?
Gasoline is one of the most dangerous substances found around the home
because it’s both highly flammable and extremely toxic. Gasoline should
never be poured on the ground, thrown in the trash or dumped down the
drain. The safest way to dispose of gasoline is to burn it in an engine.
As gasoline ages, it tends to lose some if its ability to ignite in an engine.
When stored for long periods of time, gasoline may become contaminated
with rust, dirt or water. It could also undergo a slight chemical change and
become “gummed up” or form “varnish.” But even gas presumed to be
unusable because of its age or contamination can usually be reused after
reconditioning.
Two methods exist for reconditioning gasoline—one for old gas and one
for gas contaminated with water. When working with gasoline, use extreme caution. Work outside and away
from open flame or sources of heat. Do not smoke. Remember, it’s highly flammable and toxic!
Reconditioning old gas
Old gas can be filtered and reconditioned for reuse as follows:
1. Filter gas through two layers of thin cloth or a coffee filter to remove any solids or semisolids. Once dried,
the cloth or paper filter can be disposed of in the regular trash.
2. Reuse the filtered gas by mixing it with new gas at a 1:5 ratio (1 part reconditioned gas to 5 parts new gas).
3. An octane booster may also be added to further restore quality .Octane boosters can be purchased at a gas
station or auto supply store.
Reconditioning gas contaminated with water
Most gasoline contains a small amount of water that’s burned in an engine without harm. Because of their
chemical structures, gas and water don’t mix, and water in a gas tank sinks to the bottom. Gasoline
contaminated with small or large amounts of water can be reconditioned for reuse as follows:
If there’s only a small amount of water contamination:
1. Add isopropanol, a fuel dryer, to the gas. Fuel dryers contain chemicals that break up the water and
combine it with the gas, thus preventing large amounts from entering the engine at once.
2. Reuse the gas by mixing it with new gas at a 1:5 ratio (1 part reconditioned gas to 5 parts new gas).
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Department of Solid Waste
If there’s a large amount of water contamination:
1. Allow the contaminated gas to settle for a period of time so that the gas and water separate.
2. Pour or siphon off as much gas as possible, leaving mostly water in the bottom of the original container.
(Please do not suck it off with using your mouth and a tube!)
3. The gas can be reused when mixed with new gas at a 1:5 ratio (1 part reconditioned gas to 5 parts new
gas). Isopropanol, a fuel dryer, may also be added.
4. Place the remaining liquid in a shallow container and allow it to evaporate in a well-ventilated area away
from sources of ignition and children and pets.
Another disposal option
If you don’t want to recondition the gasoline, you can always drop it off at either of the Larimer County
hazardous waste sites listed below for safe disposal or recycling.
! The Estes Park Solid Waste Transfer Station, (970) 586-6478
! The Household Hazardous Waste Collection Facility at the Larimer County Landfill, (970) 498-5760
For more information on the disposal of household hazardous wastes, contact the Larimer County
Department of Solid Waste at (970) 498-5760.
Department of Solid Waste