Does Kerosene Go Bad?

Kerosene is a fuel that is derived from petroleum. It is commonly used in lamps and heaters. Because kerosene is derived from petroleum, it can go bad over time.

Petroleum products are subject to condensation, bacteria, and mold growth when exposed to air and moisture for extended periods.

That’s right, just like milk and bread, kerosene can spoil and become unusable.

In this blog post, we’ll explore the science behind kerosene spoilage, how to tell if your kerosene has gone bad, how to properly store kerosene for extended life, and what to do with kerosene that has gone bad.

Why does Kerosene Goes Bad?

The main reason kerosene goes bad is due to condensation. When kerosene is exposed to air, moisture will condense on the surface of the liquid.

This happens because the kerosene molecules are attracted to the water molecules in the air. The water molecules will then stick to the kerosene molecules, forming a layer of water on the surface of the kerosene.

This moisture can lead to the growth of bacteria and mold, contaminating the kerosene and making it unsafe to use.

Additionally, the condensation can cause the kerosene to degrade, making it less effective as a fuel. This happens when water seeps into the kerosene, causing it to break down.

Kerosene Storage Tips for Prolonged Life

Kerosene can last for years if it is stored properly. However, if it’s not stored properly, it can go bad within a few months. Here are some recommendations to store kerosene the right way.

Kerosene Storage Containers

Kerosene is a highly flammable liquid, and as such, it must be stored properly to prevent accidental fires.

kerosene tank

The best way to store kerosene is in an opaque plastic container designed specifically for storing kerosene.

These containers are typically made of thick plastic and have a screw-top lid, which helps to prevent condensation, evaporation, and spillage.

Kerosene Storage Location

In many homes, fuel is stored inside the garage or basement. Well, these areas are probably not the best places to store the flammable liquid.

If there is a spill, the fumes could potentially ignite, causing an explosion. It’s best to store fuel in a cool, dry place.

So, what is the best location to store kerosene?

Kerosene should be kept in an outside storage shed or barn that is away from the house.

Additional Kerosene Storage Tips

  • Store kerosene in a well-ventilated area.
  • Do not store kerosene near any heat sources.
  • Ensure the container you’re using is made of a material that won’t react with kerosene
  • Make sure kerosene containers are tightly sealed.
  • Inspect kerosene containers regularly for any signs of damage.
  • Never store kerosene near food or beverages
  • Always keep kerosene away from any ignition sources.

While kerosene is generally safe to use, you should take all these precautions when storing it.

How Long Does Kerosene Last?

One of the biggest questions people have about kerosene is how long it will last before it goes bad. The answer to this question depends on a few factors, including how the kerosene is stored and how often it is used.

Generally speaking, kerosene can last for about 3 years before it starts to degrade.

However, if the kerosene is stored in a cool, dark place and is not used frequently, it can last much longer. For example, infrequently used kerosene in a lamp may last 5 years or more before it goes bad.

burning kerosene lamp

While kerosene can technically last for a few years, it’s generally best to use it within six months. This is because kerosene can start to degrade after a few months, which can cause problems with your fuel burning inefficiently.

Additionally, kerosene that has been sitting for a while can start to develop a bad smell, which can be unpleasant.

1-k vs 2-k Kerosene: Lifespan Comparison

It’s well known that the impurities content in 1-k grade kerosene is lower than in 2-k grade kerosene. And it is also known that sulfur is the main impurity in kerosene.

In this regard, it’s reasonable to think that 1-k grade kerosene may last longer than 2-k grade kerosene under similar conditions.

The lower impurities content in 1-k grade kerosene means that it’s less likely to break down to other components that will degrade and make the fresh fuel go bad.

2-k grade kerosene also has a higher chance of containing more water, which can cause the kerosene to degrade more quickly.

How to tell if Kerosene is bad?

Bad kerosene can not only be inefficient and produce less heat, but it can also produce harmful fumes, so it’s crucial to be able to identify it.

Here are five methods you can use to tell if your kerosene has gone bad:

Smoke and soot when burning

The most important indicator of kerosene quality is its smoke point. The smoke point is the temperature at which the kerosene produces smoke and soot when burned.

If the kerosene has a low smoke point, it will produce a lot of smoke and soot when burned, which can be dangerous.

To test the smoke point of kerosene, simply pour a small amount into a clean, dry container and light it with a match. If the kerosene produces a lot of smoke and soot, it’s of poor quality and possibly unusable.

Floating particles

Pour a small amount of kerosene into a clear container and observe it for any floating particles. If you see any floating particles in the kerosene, this is an indication that the kerosene has gone bad.

The particles are most likely products of hydrocarbon degradation. Good kerosene should be clear with no floating particles.

Suspended cloudy sludge

Another way to tell if kerosene has gone bad is to look for a suspended cloudy sludge at the bottom of the container. This sludge is a sign that the kerosene has begun to break down and is no longer suitable for use.

Bacteria or mold growth due to condensation can also lead to a suspended cloudy or yellow sludge.

Water bubbles

An easy way to tell if kerosene is bad is to look for water bubbles in the kerosene. If you see water bubbles, it means that the kerosene has come into contact with water and is now contaminated.

If you see water bubbles, do not use the kerosene as it will not burn properly.


If kerosene has gone bad, it will start to separate into layers. The bottom layer will be a dark sludge, while the top layer will be a clear liquid.

If you see this separation, it’s an indicator that the kerosene has gone bad and should be modified or discarded.

Can you Use Bad Kerosene?

You can use stale kerosene, but you’ll need to perform some modifications first.

Here is how to modify and improve bad kerosene in 3 easy steps:

Filter any suspended sludge or particles

Before using bad kerosene, it’s crucial that you filter any suspended sludge or particles. If you do not, these contaminants will cause serious damage to your equipment.

The best way to filter kerosene is with a coffee filter or cheesecloth. Simply pour the kerosene through the filter into a clean container. Make sure to dispose of the used filter properly.

Decant to separate kerosene and water

After filtering, you can go on to salvage your bad kerosene by decanting it. This process will separate the kerosene from the water, allowing you to use the kerosene for other purposes.

To decant bad kerosene, you will need a container with a spout, a funnel, and some paper towels.

First, pour the kerosene into the container using the funnel. Then, let the kerosene sit for a few hours so that the water can settle to the bottom.

Once the water has settled, carefully pour the kerosene into another container, leaving the water behind. Discard the contaminated water properly as it’s not safe to use.

Mix the modified kerosene with fresh kerosene

Assuming you have already filtered and decanted your bad kerosene, you can proceed to mix the modified kerosene with fresh kerosene.

The ratio should be 3 parts fresh kerosene to 1 part modified kerosene.

Once you have mixed the two together, allow the resulting mixture to sit for at least 24 hours so that the volatile compounds can evaporate.

After the mixture has had time to settle, you can then use it in your lantern without fear of damaging the wick or producing too much smoke.

The Problems of using Unmodified Bad Kerosene

Many problems can arise from using bad kerosene in heaters and lamps. The most common issues are burning inefficiencies, soot buildup, clogged wicks, and unpleasant fumes and smells.

Burning inefficiencies

Bad kerosene can contain impurities that can cause burning inefficiencies.

The combustion of bad kerosene is usually incomplete, which means that much of the fuel is wasted.

This fuel inefficiency translates into higher costs for consumers, as they have to purchase more kerosene to get the same amount of heat or light.

Soot buildup

Soot is a black, sticky substance that can build up on the walls of kerosene lamps and stoves.

Over time, soot can build up to the point where it can cause problems with the working of the lamp or stove.

Clogged lantern wicks

Another problem with using bad kerosene is that it can clog lantern wicks, making them difficult to light.

This can be a real problem if you’re trying to use your lantern in an emergency situation. Clogged wicks can also cause your lantern to smoke or produce a faint flame, which can be dangerous.

Unpleasant fumes and smell

Bad kerosene can cause unpleasant fumes and smells that can be harmful to your health. Inhaling these fumes can cause headaches, dizziness, and nausea.

Kerosene fumes can also irritate your eyes, nose, and throat. If you are using bad kerosene in a confined space, such as a small room, the fumes can be even more harmful.

How to Discard Bad Kerosene?

If you have kerosene that is more than a few years old and you feel it can’t be salvaged, it’s best to dispose of it.

Bad kerosene should be discarded following these tips:

  1. Do not pour kerosene down the drain, on the ground, or in storm drains.
  2. Bring kerosene to a hazardous waste facility for proper disposal.
  3. Before discarding, thoroughly inspect all containers that held kerosene to ensure that there are no leaks that could make the discarding process hazardous.
  4. Be sure to label the container as “hazardous waste” before taking it to the facility.
  5. Never attempt to burn bad kerosene as a way of discarding it, as it can produce harmful fumes.

What Lasts Longer Kerosene or Propane?

Kerosene and propane are two of the most common fuels used for heating and cooking. But which one lasts longer?

Kerosene has a shelf life of about three years. Since it’s an LPG, propane doesn’t go bad at all. However, this does not mean that kerosene will go bad after three years and propane will remain good forever.

Shelf life is simply the amount of time fuel can be stored before it begins to degrade.

Once kerosene or propane are contaminated, they will both only last for a few months.

That said, though, if you need fuel with an infinite shelf life, propane is the better option. But if you need a fuel that is cheaper and easier to find, kerosene is the way to go.

The Bottom Line

Kerosene can go bad if it’s not stored properly. Keeping kerosene in a cool, dry place, in thick, opaque plastic containers, and away from the house is paramount.

If kerosene is stored for too long (more than 5 years), it can become condensed and unusable. If you have kerosene that you are not sure is still good, it’s best to dispose of it properly.

If you’re looking to save some bucks, we’ve also discussed a strategy that you can use to salvage bad kerosene and reuse it in heating and lighting.