Is Sulfuric Acid Flammable? What You Need to Know

Sulfuric acid is a highly corrosive and hazardous chemical used in various industries. Its properties and characteristics make it an important part of many industrial processes, but one of the most important questions people have is whether or not sulfuric acid is flammable.

In this blog, we will explore the properties of sulfuric acid and answer the question of whether or not it is flammable.

WHAT Is Sulfuric Acid?

Sulfuric acid is a highly corrosive and dense liquid that is commonly used in a wide range of industrial and laboratory applications. It is a strong acid with the chemical formula H2SO4 and comprises hydrogen, sulfur, and oxygen atoms.

Sulfuric acid is a colourless, odourless, and oily liquid soluble in water and produces a highly exothermic reaction when mixed with water.

Sulfuric acid is one of the most widely used chemicals in the world and has many industrial applications, including in the production of fertilizers, detergents, dyes, and pharmaceuticals.

It also produces lead-acid batteries commonly used in cars and other vehicles.

Sulfuric acid is highly reactive and can cause severe burns and tissue damage if it comes into contact with the skin or eyes. Handling sulfuric acid carefully and following appropriate safety precautions when working with this chemical is important.

Is Sulfuric Acid Flammable?

The short answer is that sulfuric acid is not flammable but can cause fires. This is because of the nature of sulfuric acid, which is a highly reactive chemical. Exposure to an ignition source can produce combustible gases like hydrogen and sulfur dioxide.

In addition, sulfuric acid can cause explosions when exposed to certain materials, such as metals and organic compounds. This is due to its strong oxidizing properties. In some cases, sulfuric acid vapor can also be considered flammable.

For safety reasons, knowing the potential risks involved when working with sulfuric acid is important. The U.S. Department of Transportation’s Hazardous Materials Regulations states that sulfuric acid must be labelled as “Flammable” when the concentration exceeds 20%.

Is Sulfuric Acid Flammable

Any liquid sulfuric acid with a concentration of 20% or higher must be treated as a flammable material.


In addition, any container holding more than one gallon of sulfuric acid must be labeled with the appropriate warning and placed in an approved flammable storage cabinet.

When handling sulfuric acid, taking the necessary precautions to minimize the risk of fire or explosion is important. This includes wearing protective clothing, using the appropriate safety equipment, and working in a well-ventilated area.

Is Sulfuric Acid Corrosive?

The answer is yes; sulfuric acid is corrosive and can cause damage to materials it comes into contact with. It’s an extremely strong acid and can destroy metals, plastics, and other materials. Handling and storing sulfuric acid safely is important to avoid any potential damage.

What makes sulfuric acid so corrosive? The strong acidity of the chemical causes it to be so destructive. Sulfuric acid has a pH of 0.3, which is very low on the pH scale. The low pH means that it’s a very strong acid that can break down materials quickly.

When sulfuric acid comes into contact with many materials, it can cause damage. Metals, plastics, and other materials can be corroded or eaten away when exposed to sulfuric acid. It can also cause discoloration or staining of materials, making them look worn and dirty.

Sulfuric acid is also corrosive to the skin and can cause severe chemical burns if it comes into contact with your skin. It should be handled cautiously, and protective clothing should be worn when handling sulfuric acid.

Is sulfuric acid Explosive?

Sulfuric acid does not explode but can react with other chemicals and materials to produce explosive reactions.

Sulfuric acid is a strong oxidizing agent, which means it can react with combustible materials and release heat and gases that may ignite or explode.

It is also highly reactive with metals and can produce hydrogen gas, which is flammable and can ignite in the presence of a spark or flame.

When sulfuric acid comes into contact with certain organic materials, such as wood, paper, or cotton, it can cause spontaneous combustion and release heat and gases that may result in an explosion.

This can occur when sulfuric acid is spilled on these materials or when they are exposed to acid fumes.

In addition, sulfuric acid can react with other chemicals, such as nitric acid or hydrogen peroxide, to produce explosive mixtures that can detonate under certain conditions. These reactions can be highly exothermic and release large amounts of heat and gases, leading to explosions and fires.

Is Sulfuric Acid Toxic?

The short answer is yes; it is toxic and can be dangerous to humans and the environment if handled improperly.

The most common way that sulfuric acid is used is in batteries.

It is a key component in lead-acid batteries used in cars, other vehicles, and everyday items such as cell phones, laptop computers, and other electronics. The acid is also used in manufacturing processes such as metal plating, dyeing, and paper production.

Sulfuric acid can be hazardous when it comes into contact with skin, eyes, and mucous membranes. It can cause severe burns, especially when concentrated.

If swallowed, it can cause vomiting, diarrhea, and abdominal pain. Inhaling sulfuric acid fumes can cause irritation of the respiratory system and even death in extreme cases.


When handling sulfuric acid, wearing protective clothing, such as goggles and a face mask, and staying upwind of the fumes is important.

If a spill occurs, cleaning it up quickly and safely is important. The acid should be neutralized with baking soda or another base to reduce its corrosive properties.

Is Sulfuric Acid Fumes Toxic?

Yes, sulfuric acid fumes can be toxic if inhaled in large quantities or for extended periods. When exposed to air, sulfuric acid can release fumes that contain sulfur dioxide, a highly irritating and toxic gas.

Inhalation of sulfuric acid fumes can cause respiratory irritation, coughing, wheezing, and difficulty breathing. Prolonged fume exposure may lead to chronic respiratory problems like bronchitis, emphysema, or asthma. In addition, sulfuric acid fumes can irritate the eyes, nose, and throat, causing redness, burning, and inflammation.

To prevent exposure to sulfuric acid fumes, working in a well-ventilated area and avoiding working with the acid in enclosed spaces or without appropriate ventilation is important.

Personal protective equipment, such as a respirator, goggles, and gloves, should also be worn to prevent contact with the acid and inhalation of the fumes.

If exposure to sulfuric acid fumes occurs, affected individuals should move to an area with fresh air, seek medical attention if necessary, and decontaminate any contaminated clothing or equipment.

What Is Sulfuric Acid Used For

Sulfuric acid has a wide range of industrial and laboratory applications and is one of the most widely used chemicals in the world. Some common uses of sulfuric acid include:

Production of fertilizers: Sulfuric acid is used in producing phosphate fertilizers, commonly used in agriculture to promote plant growth.

Refining of petroleum: Sulfuric acid is used to refine crude oil to remove impurities and produce high-quality petroleum products.

Production of detergents and cleaning agents: Sulfuric acid is used in producing cleaning agents, such as laundry detergents and drain cleaners.

Production of dyes and pigments: Sulfuric acid is used in the production of dyes and pigments for use in textiles, paints, and other applications.

Production of pharmaceuticals: Sulfuric acid produces many pharmaceuticals, including antibiotics, pain relievers, and other medications.

Lead-acid batteries: Sulfuric acid is used in producing lead-acid batteries, commonly used in cars and other vehicles.

Pickling of metals: Sulfuric acid is used for pickling metals, such as steel and iron, to remove impurities and prepare the surface for further processing.

pH control: Sulfuric acid is used as a pH adjuster in a wide range of industrial processes, such as in producing paper, textiles, and food products.

Overall, sulfuric acid plays a critical role in many industrial processes and is an essential chemical for producing a wide range of products used in our daily lives.

Can You Burn Sulfuric Acid?

The answer is no. You cannot burn sulfuric acid. Sulfuric acid is highly corrosive and can cause serious damage to the skin and other materials. Even small amounts of sulfuric acid can cause irreparable damage if it comes into contact with any material it is not intended to be in contact with. This includes clothing, skin, and other surfaces.

Sulfuric acid is also very flammable. If it were to come into contact with an open flame or spark, it could quickly cause a dangerous fire. This is why it is important to always handle sulfuric acid with extreme caution and to keep it away from any heat source.

In general, sulfuric acid should never be purposely burned. If you do come into contact with sulfuric acid, you should immediately get away from the area and seek medical attention if necessary.

Additionally, it would be best never to attempt to neutralize sulfuric acid with other chemicals, as this can lead to dangerous reactions.

For safety purposes, trained professionals should only handle sulfuric acid in a laboratory setting. This is the only place where it can be safely handled and disposed of without risk of hazardous reactions.

Can Sulfuric Acid Burn Metal?

Yes, sulfuric acid can burn or corrode many metals, especially those that are reactive with acids. Sulfuric acid is a strong and highly corrosive acid that can eat away at metals and other materials over time.

Sulfuric acid reacts with metals by breaking down the metal’s protective oxide layer and producing hydrogen gas. This reaction can cause the metal to dissolve or corrode, leading to damage or failure of the metal structure.

The extent of the corrosion depends on several factors, including the sulfuric acid concentration, the temperature, the type of metal, and the exposure time. Some metals, such as aluminum, are particularly susceptible to corrosion by sulfuric acid, while others, such as stainless steel, are more resistant.

Sulfuric Acid Density

Sulfuric acid has a density of 1.84 g/cm3, much higher than water (1 g/cm3). Its high density allows it to be used in various applications, such as battery production, chemical manufacturing, and wastewater treatment.

The density of sulfuric acid can vary based on two different factors.

First, the concentration of sulfuric acid can affect its density.

The higher the concentration of sulfuric acid, the higher the density. Second, the temperature of the sulfuric acid can also affect its density. Generally, the higher the temperature, the lower the density of sulfuric acid.

Sulfuric acid is also a highly corrosive acid. It reacts with various metals and other materials, so it’s important to handle it with extreme care.

Safety precautions must be taken when using sulfuric acid, including proper acid storage, wearing protective equipment, and proper ventilation.

Sulfuric Acid Hazards

Sulfuric acid is a hazardous chemical that can pose several health and safety risks if improperly handled. Some of the hazards associated with sulfuric acid include:

Corrosivity: Sulfuric acid is highly corrosive and can burn or destroy skin, eyes, and clothing on contact.

Inhalation hazards: Sulfuric acid can release harmful fumes and vapors that can irritate the respiratory tract, cause coughing and difficulty breathing, and lead to chemical pneumonitis (inflammation of the lungs).

Fire and explosion hazards: Sulfuric acid is not flammable, but it can react violently with other chemicals and materials, such as organic materials and metals, to produce flammable gases or cause explosions.

Environmental hazards: Sulfuric acid is a potent acid that can cause serious environmental damage if released in large quantities, such as by accidental spills or leaks.

Does Sulfuric Acid Burn Skin

Yes, sulfuric acid can burn and damage the skin on contact. Sulfuric acid is a highly corrosive substance that can cause severe chemical burns to the skin, eyes, and respiratory tract.

When sulfuric acid comes into contact with the skin, it reacts with the proteins and lipids in the skin cells, causing tissue damage and destruction.

The severity of the skin damage depends on the concentration and duration of exposure, as well as the amount of acid that comes into contact with the skin.

Brief exposure to a dilute sulfuric acid solution may cause mild skin irritation, while prolonged or repeated exposure to a concentrated solution can cause severe burns, necrosis, and scarring.

Symptoms of sulfuric acid burns on the skin may include redness, swelling, pain, and blistering. If you are exposed to sulfuric acid and develop these symptoms, it is important to seek immediate medical attention.

Rinse the affected area with copious amounts of water for at least 20 minutes, remove any contaminated clothing or jewelry, and seek medical attention immediately.

What Happens If You Inhale Sulfuric Acid?

Inhaling sulfuric acid can be extremely dangerous and can cause serious respiratory problems. Sulfuric acid can release harmful fumes and vapors that can irritate the respiratory tract, cause coughing and difficulty breathing, and lead to chemical pneumonitis (inflammation of the lungs).

When inhaled, sulfuric acid reacts with the respiratory tract’s moisture to form sulfuric acid aerosols, which can cause immediate burning and irritation of the nose, throat, and lungs.

The severity of the effects depends on the concentration and duration of exposure, as well as the individual’s age, health, and sensitivity to the acid.

Acute exposure to high concentrations of sulfuric acid can cause serious lung damage, including bronchospasms, pulmonary edema, and chemical burns to the respiratory tract.

Long-term exposure to low concentrations of sulfuric acid can also lead to chronic respiratory problems, such as bronchitis, emphysema, and asthma.

If you inhale sulfuric acid, you should seek medical attention immediately. Move to an area with fresh air and remove any contaminated clothing. Rinse your mouth and nose with water, and do not induce vomiting.

If you are experiencing severe respiratory symptoms, such as difficulty breathing or chest pain, seek emergency medical treatment.

Does Water Neutralize Sulfuric Acid?

When sulfuric acid is mixed with water, it does become neutralized or less acidic. However, this does not mean it is safe to use or touch.

Depending on the sulfuric acid concentration, the water may still be corrosive, and it is important to take the proper safety precautions when handling sulfuric acid.

The neutralization of sulfuric acid with water is a chemical reaction. In this reaction, hydrogen ions from the water molecules react with the sulfuric acid molecules to form sulfate ions, which are neutral in their charge. This reaction produces a less acidic solution.

In addition to neutralizing sulfuric acid, water can also be used to dilute sulfuric acid. Adding more water to the sulfuric acid will make the solution less acidic.

However, it is important to note that diluting sulfuric acid with water can produce a corrosive solution that still risks human health and safety.

Sulfuric Acid Safety Precautions


Sulfuric Acid Safety Precautions

Sulfuric acid is a highly corrosive and hazardous substance that should be handled cautiously. Here are some safety precautions that should be taken when working with sulfuric acid:

Wear proper personal protective equipment (PPE): Goggles, a face shield, gloves, a lab coat or apron, and chemical-resistant boots. Ensure that all PPE is properly fitted and in good condition.

Use proper storage containers: Store sulfuric acid in a properly labeled, leak-proof container made of materials compatible with the acid. Never store sulfuric acid in a metal container, as it can corrode the metal and create a risk of leakage.

Handle with care: When handling sulfuric acid, use extreme caution and avoid splashing or spilling the acid. Add acid to water slowly and stir continuously to prevent overheating and splashing.

Ventilate the area: Sulfuric acid can release harmful fumes and vapors, so ensure the work area is well-ventilated. Use a fume hood or work in a well-ventilated area to avoid inhaling the fumes.

Know the hazards: Educate yourself on the hazards of sulfuric acid, including its corrosive and toxic properties and the potential for explosive reactions. Know what to do in case of an accident or emergency.

Have an emergency plan: Develop and implement an emergency plan in case of accidental exposure to sulfuric acid. This should include first aid procedures, evacuation procedures, and emergency contact information.

Follow proper disposal procedures: Sulfuric acid is a hazardous waste and should be disposed of properly according to local regulations. Never pour sulfuric acid down the drain or dispose of it in the regular trash.


Sulfuric acid is not flammable, as it does not easily ignite or support combustion.

However, it can react violently with certain substances, such as water and metals, producing flammable hydrogen gas or other hazardous products.

Additionally, sulfuric acid can react with organic materials, such as wood and paper, to produce heat and potentially ignite the materials. Therefore, while sulfuric acid is not flammable, it should be handled cautiously and stored and used under proper safety procedures.