Gasoline is everywhere around us, from vehicles to generators, and it’s not uncommon to find an old can of it tucked away in some corner of the garage. However, gasoline loses its value over time, and it’s not something we should keep for too long. My grandpa had a great solution for dealing with old gasoline—he’d use it to light up bonfires. Those were different times, and people back then were quite bold.
Today, we need solutions that are more environmentally conscious. Petroleum-based fuels can pose serious health, environmental, and fire hazards if not stored and disposed of properly. So, here are the right ways to dispose of old gas in a manner that’s safe and responsible.
How Long Does Gasoline Last, Can It Go Bad?
Gasoline doesn’t last forever, and it can indeed go bad over time. For the most part, the gas in your everyday car or the lawnmower you use every week should be fine for a few months. It generally takes a while for the quality to drop enough to be a concern.
However, if you have gas-powered machines that you only use occasionally, like boat motors, classic cars, or chainsaws, running them on old gasoline can cause poor performance and even engine damage. It might surprise you, but gasoline can actually “go bad.”
Regular vehicle fuel remains usable in your gas tank for up to six months, while diesel can last up to a year. Keep in mind that it can take up to a month for gas to travel from the refinery to your tank, so the gas in your idle vehicle could be older than you realize.
Old gas that’s still clean can be used, although it may not perform as well as fresh gas because its chemical properties change over time. If you’ve got an idle vehicle, it’s best to check the gas quality before starting it up. Pure gasoline typically lasts up to six months before it starts to degrade from oxidation, and any water that finds its way into the gasoline sinks to the bottom of the tank. To avoid putting water into your tool or vehicle, don’t use the last bit of gasoline.
As we mentioned earlier, Pure gasoline has a lifespan of three to six months, while ethanol gas, which breaks down faster, can last up to three months. Remember, the gas you pump at the station might already be a few weeks old by the time it’s in your tank. Over time, hydrocarbons in gasoline react with oxygen, forming gummy solids, and the lighter components evaporate, leaving a thickened mixture that doesn’t burn well.
Most of the gas sold in the U.S. contains ethanol, which reduces harmful emissions but attracts moisture. This can cause gasoline to absorb water, especially if it’s stored in places with fluctuating temperatures. Storage conditions, like temperature and container quality, can also impact gasoline’s shelf life. So, if you’ve got old gas, it’s a good idea to check it before using it to avoid any potential problems.
Why Does Gasoline Go Bad?
Gasoline goes bad for several reasons, and understanding these can help you avoid engine problems.
First off, gasoline is made up of hydrocarbons refined from crude oil, which provide the power your engine needs. It also contains various chemical compounds to prevent corrosion and keep the fuel stable. However, even with these additives, gasoline will eventually evaporate and oxidize, breaking down into a sludgy varnish that can clog your engine’s fuel system.
Over time, rust, dirt, and other contaminants can find their way into the gas tank. These contaminants can then end up in your fuel filter, carburetor, or fuel injectors, causing sluggish performance or even stopping your engine entirely.
Water and alcohol are two substances in gasoline that are particularly hard on fuel systems and can sometimes lead to your car failing to start up. Water can be absorbed into gasoline from direct contact or from moisture in the air. Alcohol, often added as a fuel additive, can separate out from gasoline over time. When there’s too much water, it can force the alcohol out of the gasoline, and these two will settle at the bottom of your tank. If this mixture gets pulled into the fuel lines, it can cause significant problems.
Good gasoline should be light in color, clear, and free of sediment and water, which tends to collect at the bottom of a poured sample. It should also smell like gas. If your gasoline is cloudy or dark, contains particles, or has a sour smell, it’s probably old. The easiest way to check is to pour some into a clear container and compare it to fresh gas.
How To Safely Dispose Gas
Getting rid of old gasoline safely is crucial to avoid environmental and health hazards. Here are several ways to dispose of it properly:
Visit a Hazardous Waste Facility or Recycling Center
Many household hazardous waste (HHW) facilities and recycling centers will accept used gasoline. Check their websites or give them a call to confirm if they accept old gas and whether there’s a fee involved. Note that these facilities typically serve local residents, and some recycling centers might charge a small fee for accepting vehicle fluids like gasoline.
Participate in Community Collection Events or Contact Local Services
Many municipalities host periodic collection events for hazardous materials, including gasoline. Not all events accept used gasoline, so check the list of acceptable items before you go. Additionally, some fire stations accept old gasoline and send it to the proper recycling facilities. Since not all fire departments offer this service, check with your local station first. Local auto repair shops or garages might also take uncontaminated gasoline off your hands.
Check State and Local Regulations for Disposal Options
If none of the above options work, reach out to your state’s environmental protection department for guidance. Rules for gasoline disposal vary by state and locality, so check with your town, city, or county to find out what regulations apply to you. It’s important to minimize fuel waste by avoiding overfilling power equipment fuel tanks near the end of the season and adding fuel stabilizer to new gasoline to extend its life.
To check if your gasoline is old or contaminated, pour some into a clear container and compare it with fresh gasoline in another container. If the old gas smells sour, looks darker, or contains rust, dirt, or sediment, it’s likely too old or contaminated to use. If the gasoline is old but not contaminated, you can still use it by mixing it with fresh gasoline in your tank (using more fresh gas than old). This dilutes the old gas enough to burn properly in your engine without causing significant performance issues.
