Is Motor Oil Flammable? (Vital Analysis)

Your car’s engine needs oil to function, making motor oil a critical fluid in the engine. The oil also serves as a lubricant, thus ensuring that the moving engine parts do not wear quickly due to friction.

When changing your car’s oil, you might wonder if motor oil can catch fire to avoid any fire outbreak. But is motor oil flammable? Will a lighted cigarette or match stick simply cause a fire hazard?

Technically, motor oil is not flammable going by the definition of flammable oils. According to OSHA, flammable liquids are liquids with very high flashpoints. Motor oil doesn’t fall under this category, having a Flashpoint of about 419 degrees Fahrenheit (215 degrees Celsius).

Here’s what you need to know about motor oil and how to stay safe around them.

Is Motor Oil Flammable?

It can be argued that almost everything can be flammable in the right circumstances. However, going by the actual definition of flammable liquids, motor oil doesn’t fall under the categories of flammable liquids.

To understand this, we must differentiate between flammable and combustible materials. Combustible materials can burn in air, while flammable materials are combustible but ignite easily on fire exposure.

Motor oil with the right amount of heat can catch fire, although at a significantly lower degree.  It can, however, be argued that motor oil falls under the category of both combustible and flammable oils.

This is because combustible fluid is defined as any fluid with a flash point lower than its boiling point.

Can Motor Oil Cause Fire?

Is Motor Oil Flammable

A follow-up to whether or not motor oil is flammable is to know if the oil can cause fire on its own. From the high flash point of motor oil, one can deduce that the fluid will need lots of heat to burn.

This technically means that motor oil cannot be the primary cause of a fire hazard but can exacerbate the situation in the right circumstances.

Remember that motor oil wasn’t classified as a flammable liquid because it requires a much higher temperature to combust. For motor oil to burn rapidly, it has to be in the presence of an ignition source (flashpoint), at around 300-400 degrees Fahrenheit

Why Is Engine Motor Oil Not Flammable?

It has been mentioned that certain persons might argue that motor oil is flammable. But technically speaking, the fluid is not exactly flammable due to its high flashing point.

For a fluid to be classified as flammable, it has to have short chains of hydrocarbons that are easy to release vapor. The quick release of vapor thus allows them to be ignited at low temperatures.

This means that motor oil does evaporate rapidly like other fluids such as gasoline because it has intermolecular forces – this simply means that motor oil molecules take a longer time to break apart.

Now imagine the trillions of molecules present in a gallon of liquid and how long it will take it to vaporize.

Also, motor oil has a heavier liquid which simply translates to it having longer molecules than most flammable liquids.

For motor oil to catch fire, it will need a pretty high temperature to force its molecule apart faster and weaken the intermolecular forces enough to produce a vapor.

Either way, for safer practices, you shouldn’t be flame close to motor oil. Remember that while motor oil is not a flammable oil, it is still a combustible liquid.

What Are the Types of Motor Oil?

There are two basic two types of motor oil: conventional motor oil and synthetic motor oil. Conventional motor oil is also mineral oil which means that it is a crude oil derivative.

Conventional oil is a friction beater, an engine sludge cleaner, a neutralizer for acids from fuels. It helps in sealing piston rings and cooling the engine.

As for synthetic oil, it was formulated around the late 1930s and early 1940s to replace crude oil, which was becoming rare in Germany. It was increasingly used very well in the military conquest as of that time.

Is Synthetic Engine Oil Flammable?

This should be a good follow-up question as to the nature of motor oil flammability. Tracing the history of synthetic oil, we discover that the oil was used in the military because it retained its viscosity in very low temperatures.

The oil was appreciated because it reduced friction drastically and worked extremely well under really high temperatures.

When discussing the flammability nature of synthetic oil, we discover that synthetic oil flash point varies between 440-degrees Fahrenheit for standard brands.

Compared to conventional motor oil, which has a flashpoint of around 302 to 392-degrees, it is lower.  This simply means that synthetic oil is even less flammable than conventional oil.

Safe Ways to Handle Motor Oil

Even though motor oil is not exactly flammable, remember it has combustible materials, so you don’t want to bring a flame extremely close to it. Thus, you need to adopt some safety measures when handling motor oil.

Below are some safety measures to adopt:

  • Keep the bottle of motor oil well ventilated
  • Find ways to contain motor oil spills
  • Keep motor oil away from potential ignition sources (at least 3 meters (10 yards) away from it)

Conclusion

Is motor oil flammable? Well, when it comes to the big question of whether or not motor oil is flammable, the simple answer to the question is No. however, the oil is combustible. Thus, you will need to adopt some safety measures when handling it.

As to synthetic and conventional oil, we discover that synthetic oil is less flammable compared to conventional oil.

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