Is Antifreeze Flammable? The answer might surprise you!

As car owners, we often focus on keeping our vehicles in top shape by regularly checking the oil, brakes, and tires.

However, one crucial component often goes overlooked – the coolant or antifreeze. This fluid regulates the engine’s temperature and prevents it from overheating.

But have you ever wondered if coolant or antifreeze is flammable? It’s a common question that deserves an answer, and in this article, we will explore this topic in-depth.

Is Antifreeze Flammable?

What Is Antifreeze?

Antifreeze, also known as engine coolant, is a liquid substance used in vehicle engines to regulate their temperature.

It is a mixture of chemicals, typically ethylene glycol or propylene glycol, and other additives.

These additives help enhance the performance and protection provided by the antifreeze.

The primary function of antifreeze is to prevent the engine coolant from freezing in cold temperatures and boiling in hot temperatures.

It achieves this by altering the freezing and boiling points of water, which is the main component of engine coolant.

In cold conditions, antifreeze lowers the freezing point of the coolant, preventing it from solidifying and potentially damaging the engine and cooling system. It also raises the boiling point of the coolant, enabling.

Is Antifreeze Flammable? 

Yes, antifreeze is flammable. Antifreeze, also known as engine coolant, is typically a mixture of ethylene glycol, propylene glycol, and other additives.

While it is primarily used to lower the freezing point and raise the boiling point of engine coolant, it does have some flammable properties.

Ethylene glycol, a common antifreeze component, is flammable and can burn in the presence of an ignition source.

It has a relatively low flash point, the minimum temperature at which it can vaporize and ignite in the air. The specific flash point can vary depending on the concentration of ethylene glycol in the antifreeze mixture.

Handling and storing antifreeze carefully is important, following the manufacturer’s instructions and taking necessary safety precautions. Proper ventilation and avoiding ignition sources are crucial to minimizing fire risk when working with or around antifreeze.


Is Antifreeze Corrosive

The answer to this question is yes. Antifreeze can be corrosive to certain engine components. Antifreeze contains chemicals such as ethylene glycol or propylene glycol, which can be harmful if they come in contact with certain metals or materials.

One of the most common materials that antifreeze can corrode is aluminum. Many modern engines are made with aluminum parts, which can be especially vulnerable to corrosion from antifreeze.

Over time, the aluminum can become pitted and weakened, leading to leaks or other problems.

Antifreeze can also corrode other brass, copper, and solder materials. These materials are commonly found in the radiator, water pump, and other parts of the engine.

If the antifreeze comes into contact with these materials, it can cause corrosion and damage to the engine.

Is Antifreeze Toxic

Yes, antifreeze can be toxic to humans, animals, and plants. The main ingredient in most antifreeze formulations, ethylene glycol, is highly toxic if ingested.

It can cause severe health problems, including kidney damage, central nervous system, and even death. Even small amounts of ethylene glycol can be harmful to humans.

Antifreeze is also toxic to animals, especially cats and dogs. Pets are attracted to the sweet taste of antifreeze and may ingest it if it is accessible. Ingestion of antifreeze can lead to poisoning and serious health issues in animals, often resulting in organ failure and death if not treated promptly.

Toxic to plants, the toxic components in antifreeze can also have detrimental effects. If antifreeze leaks or is improperly disposed of, it can contaminate soil and water, negatively impacting plant growth and potentially leading to plant death.

Types Of Antifreeze

There are primarily two types of antifreeze commonly used:

Ethylene Glycol Antifreeze: This is the most common type of antifreeze and is typically green. It comprises ethylene glycol as the main component and various additives to enhance its performance.

Ethylene glycol-based antifreeze has excellent heat transfer properties and a wide temperature range, making it suitable for most vehicles.

Propylene Glycol Antifreeze: Propylene glycol-based antifreeze is an alternative to ethylene glycol antifreeze. It is often used as a more environmentally friendly option because it is less toxic and poses lower risks to animals and humans if accidentally ingested. Propylene glycol antifreeze is typically orange or pink in color.

Both types of antifreeze offer freeze protection and help prevent engine overheating. It is important to consult the vehicle manufacturer’s recommendations or the antifreeze product label to determine which type of antifreeze is suitable for your specific vehicle.

Mixing different types of antifreeze is generally not recommended, as it can lead to reduced performance and potential damage to the cooling system.

Is Antifreeze Flammable Or Combustible?

The answer is yes, it is both. Antifreeze is a flammable liquid, which means it can ignite and burn. However, it is not highly combustible, so it is not easy to ignite and burn.

Antifreeze requires a relatively high temperature to ignite, around 437 degrees Fahrenheit.

It is important to note that while antifreeze is flammable and combustible, it is not explosive. Explosive materials release energy rapidly and violently, causing a sudden increase in pressure and temperature.

Antifreeze, however, does not release energy in this way and therefore is not explosive.

Flash Point Of Antifreeze

The flash point of antifreeze can vary depending on the specific formulation and concentration of chemicals used. However, in general, the flash point of ethylene glycol-based antifreeze is typically around 111°C (232°F) to 116°C (241°F).

Propylene glycol-based antifreeze, on the other hand, has a slightly higher flash point, typically ranging from 110°C (230°F) to 115°C (239°F).

It’s important to note that the flash point represents the minimum temperature at which the vapors of a substance can ignite when exposed to an open flame or spark.

Antifreeze should be handled and stored cautiously, ensuring proper ventilation and avoiding ignition sources to minimize the risk of fire or ignition.

Why Is Antifreeze So Important For Vehicle Engines?

Antifreeze is important for vehicle engines due to the following reasons:

Freeze Protection: Antifreeze prevents the engine coolant from freezing in cold temperatures. When water-based coolant freezes, it expands and can cause damage to the engine block, radiator, and other components.

By lowering the freezing point of the coolant, antifreeze ensures that the coolant remains in a liquid state even in extremely cold weather conditions, providing freeze protection for the engine.

Boiling Point Elevation: Antifreeze also raises the boiling point of the engine coolant. As the engine operates, it generates heat, and the coolant absorbs that heat to prevent the engine from overheating.

By increasing the boiling point of the coolant, antifreeze enables it to withstand higher temperatures without vaporizing and losing its cooling capabilities. This helps to prevent overheating and potential engine damage.

Heat Transfer: Antifreeze improves the efficiency of heat transfer in the engine. It has higher heat conductivity than water alone, allowing it to absorb heat more effectively from the engine components.

This helps to regulate the engine temperature and maintain it within the optimal operating range, promoting efficient combustion and preventing overheating.

Corrosion Prevention: Antifreeze contains additives that help protect the engine and cooling system from corrosion. These additives form a protective layer on metal surfaces, preventing the formation of rust and other corrosive deposits.

Antifreeze helps prolong the lifespan of the engine and cooling system components by inhibiting corrosion, ensuring their proper functioning.

Lubrication: Some antifreeze formulations include lubricating additives that help reduce friction and wear within the engine. This can contribute to improved engine performance and longevity.

What Happens If You Burn Antifreeze?

When antifreeze is burned, it produces several harmful chemicals, including formaldehyde and acetaldehyde.

These chemicals can cause respiratory problems, headaches, and other health issues. Additionally, they can contribute to air pollution and increase the risk of smog.

Furthermore, burning antifreeze can release heavy metals and other contaminants into the environment. These pollutants can contaminate soil and water, posing a risk to plants, animals, and humans.

In addition, improper disposal of antifreeze can result in fines or other legal consequences.

Furthermore, burning antifreeze in an enclosed space, such as a garage or workshop, can also increase the risk of a fire or explosion.

This is because the fumes from burning antifreeze can be highly flammable, and any open flames or sparks in the area can ignite the fumes and cause a fire.

Is Antifreeze Hazardous Waste

Yes, antifreeze is considered a hazardous waste due to its toxic properties. Antifreeze, particularly formulations containing ethylene glycol, can harm humans, animals, and the environment if improperly handled and disposed of.

It is classified as hazardous waste because it contains toxic, flammable substances and potentially damages ecosystems if released into the environment.

When disposing of antifreeze, it is important to follow local regulations and guidelines for hazardous waste disposal.

Many jurisdictions have specific requirements for collecting, recycling, or properly disposing of used antifreeze. It should not be poured down drains, sewers, or dumped into the environment.

Can You Mix Different Types Of Antifreeze?

The short answer is no, it’s not recommended to mix different types of antifreeze. This is because different types of antifreeze are formulated with different chemicals and additives that can react negatively when mixed.

This can lead to reduced effectiveness in the cooling system and even damage to the engine.

It’s important to understand the different types of antifreeze and their specific formulations. The most common types of antifreeze are ethylene glycol and propylene glycol.

Ethylene glycol is the traditional type of antifreeze, while propylene glycol is a newer, less toxic antifreeze that is often used in environmentally conscious applications.

There are also different colors of antifreeze, which can be confusing. The color of antifreeze is not an indicator of its type or compatibility with other types of antifreeze.

It’s important to consult your vehicle’s owner’s manual or a trusted mechanic to determine the correct type of antifreeze for your specific make and model.

Safety Precuations while Using Antifreeze

When using antifreeze, following safety precautions to minimize potential risks is important. Here are some safety precautions to consider:

Read and Follow Manufacturer Instructions: Carefully read and follow the instructions provided by the manufacturer on the product label or safety data sheet (SDS). These instructions will provide specific guidance on handling, storage, and disposal of the antifreeze.

Use Personal Protective Equipment (PPE): Wear appropriate protective equipment, such as gloves and safety glasses, when handling antifreeze. This helps prevent skin contact and eye irritation.

Ensure Adequate Ventilation: Work in a well-ventilated area to avoid inhaling vapors. Consider using a ventilation system or wearing a respirator if working in an enclosed space.

Avoid Contact and Ingestion: Avoid direct contact with antifreeze and avoid ingesting it. Ethylene glycol-based antifreeze is toxic if ingested; even small amounts can be harmful.

Keep antifreeze away from food, beverages, and areas where people or animals may accidentally come into contact with it.

Store Antifreeze Properly: Store antifreeze in tightly sealed containers in a cool, dry place away from direct sunlight and sources of heat or ignition. Ensure that containers are properly labeled to prevent confusion.

Clean Up Spills Promptly: In case of spills or leaks, clean them up immediately using appropriate absorbent materials. Do not allow antifreeze to enter drains, sewers, or bodies of water, as it can contaminate the environment.

Dispose of Antifreeze Properly: Follow local regulations and guidelines for the proper disposal of antifreeze. Many areas have specific collection centers or recycling facilities for used antifreeze. Do not dispose of antifreeze in household waste or pour it down the drain.

Keep Antifreeze Away from Children and Pets: Store antifreeze out of reach of children and pets. The sweet taste of antifreeze can be attractive to animals, but it is highly toxic if ingested.

If you have any concerns or accidents involving antifreeze, seek medical attention or contact a poison control center immediately.

Always prioritize safety when handling antifreeze to protect yourself, others, and the environment.


Antifreeze is considered flammable. Although its primary purpose is to regulate engine temperature and prevent freezing and overheating, antifreeze contains substances such as ethylene glycol that are flammable and can burn in the presence of an ignition source.

It is important to handle antifreeze cautiously, follow safety guidelines, and avoid exposing it to open flames or sparks.

Proper storage, ventilation, and adherence to manufacturer instructions are necessary to minimize fire risk and ensure safe antifreeze handling.