How to Dispose of Sulfuric Acid (at Home and Lab)

Sulfuric acid is a corrosive and highly-reactive chemical that you should handle with extreme caution.

The Agency of Toxic Substances and Disease Registry recommends not letting sulfuric acid end up in landfill sites or waste disposal plants.

It can be a substantial environmental hazard and cause the death of wildlife.

Therefore, today we will be discussing how to dispose of sulfuric acid at home and in the lab safely.

Let’s begin!

How to Dispose of Sulfuric Acid at Home?

You might have bought some sulfuric acid for your home for various uses.

If there is some leftover, trying to store it is way more challenging than disposing of it. Follow these steps for the proper disposal of sulfuric acid at home.

Step 1

Gather all the acid you wish to dispose of on a concrete pad. Remember not to place it on grass or soil as the high acidity levels will damage it.

Your driveway or the patio is the perfect place for acid disposal.

Step 2

If you’re trying to get rid of batteries, pour out all the acid in a thick plastic container that won’t break down.

You can check the plastic’s sturdiness by pouring a small volume of acid first and leaving it in the container for a few minutes.

Step 3

Put on heavy-duty rubber gloves and overalls to eliminate any chances of skin exposure to the acid.

Now, it’s time to pour out all the acid into your container.

Step 4

Fill another large container with water.

Slowly add some of the acids to this container and stir it gently.

Step 5

Add in baking soda, one tablespoon at a time, to the acid and water mixture. The solution will bubble up and foam.

This indicates that the soda is working, and your acid is getting neutralized.

Step 6

Continue adding the soda and stirring well. Once the foaming and bubbling pauses, add another tablespoon of soda and see if a further reaction occurs.

If not, your mixture is fully neutralized and ready to be poured down the drain safely.

Step 7

Repeat this process with the rest of the acid. Once all the neutralized acid is disposed of, run lots of water down the drain for at least five minutes.

Important Note – it is vital to remember to pour small volumes of acid into the water and not the other way around.

If you pour water into the acid, it will undergo a harsh exothermic reaction and produce immense amounts of heat. This is extremely dangerous for you and the environment.

How to Dispose of Sulfuric Acid in a Lab?

In the lab, you are surrounded by various chemicals that can be used to neutralize sulfuric acid for safe disposal.

In this section, we have discussed all the chemicals that react with sulfuric acid. We have also determined which would be the best choice of chemical to use.


Zinc reacts with sulfuric acid to produce hydrogen gas, zinc sulfate salt, and water.

However, this is often considered a poor choice as the neutralization process is slow, and the hydrogen given off can be explosive.

Calcium Carbonate

The second chemical to consider is calcium carbonate. Calcium carbonate will react with sulfuric acid to form calcium sulfate (also called gypsum) and carbon dioxide.

This is a commonly used reaction to dispose of sulfuric acid in the lab. The gas produced isn’t harmful, and calcium sulfate is a fairly innocuous substance.

Sodium Hydroxide

This would react with sulfuric acid to form sodium sulfate and water. Seems safe enough, right?

In reality, sodium hydroxide is a very difficult chemical o handle. It absorbs water from the air and can cause severe burns in case of skin exposure.

Sodium hydroxide is known to eat off your flesh and cause damage to your nerves.

Moreover, the reaction with sulfuric acid is exothermic, thus producing extensive amounts of heat with the chances of a thermal explosion.

Sodium Carbonate

Lastly, we have sodium carbonate. This is the best possible choice as it is safe to store, easy to use, and neutralizes sulfuric acid quickly.

The byproducts include sodium sulfate salt, which is non-hazardous and can be swept away with a broom. It also produces carbon dioxide, which is also a safe gas. We have a winner!

Important Things to Note

When you’re disposing of sulfuric acid, there is always a chance of accidental exposure. You should always wear the appropriate protective equipment to reduce these chances.

Also, read up on the right steps to take in case of chemical exposure mentioned below. This will help you minimize injury and burns in case of an accident.

In Case of Skin Contact

If the acid has made contact with your skin, you will need to flush the exposed area with copious amounts of water.

Run room temperature water over that area for at least 15 minutes and then seek medical attention immediately.

If the exposure has occurred over a larger area, remove your clothing and rinse it thoroughly under a lukewarm shower. Then, it would be best if you headed off to the ER.

In Case of Ingestion

If there has been an accidental case of ingestion, you will need medical help immediately.

Don’t try to drown it with water or anything else. Instead, you should head off to your nearest hospital.

In Case of Inhalation

If you end up breathing in sulfuric acid, don’t panic. The smell is horrible but mostly harmless. You should more outdoors for some fresh air and breathe in deep.

However, if you mistakenly inhale fumes from a concentrated form of sulfuric acid, you might notice difficulty in breathing.

In such circumstances, it is best to seek medical help instead of handling it on your own.

The ER team is better equipped to assess your condition and determine whether the acid has caused damage to your respiratory tract.

Frequently Asked Questions

Due to sulfuric acid’s hazardous nature, people had many concerns and questions about safe disposal practices.

We scoured the Internet to collect some of the most frequently asked questions.

Below, we have done our best to clarify the doubts so you can dispose of sulfuric acid effectively, safely, and without harming the environment.

Can You Pour Sulfuric Acid Down the Drain?

Whether you can pour sulfuric acid down the drain depends on the concentration and quantity you have.

Lower concentrations and smaller amounts can be safely disposed of by flushing in the toilet or pouring down the drain.

In its diluted form, sulfuric acid is sewer and septic safe. It will continue mixing with water for an even lower concentration as it goes down the water pipes.

Moreover, pouring small volumes of sulfuric acid down the drain can even help you with clogged drains.

If your house or lab has plastic piping, you can pour sulfuric acid through them to eliminate any obstructions within an hour.

Can Sulfuric Acid Eat Through Plastic?

Yes, it can, but not always.

Most people prefer disposing of excess sulfuric acid as it poses a serious storage challenge. Sulfuric acid is a very heavy chemical and can be quite sharp at high concentrations.

If stored without being diluted first, the acid will retain its aggressive chemical nature and oxidize plastic containers. It can even corrode metals.

Therefore, you should always try to neutralize or dilute the acid before storing it.

Is it Dangerous to Smell Sulfuric Acid?

Sulfuric acid smells like rotten eggs. It isn’t dangerous but might leave you plugging your nose at the repulsive smell.

However, care should be taken when handling sulfuric acid in a concentrated form.

Inhalation of concentrated sulfuric acid can irritate your upper respiratory tract and cause difficulty in breathing.

If the inhalation continues for an extended time, it may even lead to lung damage.

How do You Neutralize Sulfuric Battery Acid?

The most effective way to neutralize sulfuric battery acid is by using sodium bicarbonate (or baking soda).

Just grab some from your kitchen and mix it into the acid for the neutralization reaction to take place.

Is Sulfuric Acid a Hazardous Waste?

Due to its corrosive nature, sulfuric acid is considered hazardous waste. It can be destructive to your eyes, skin, lungs, and even teeth in concentrated forms.

Severe exposure can lead to loss of life. That is why extreme caution needs to be taken when determining how to dispose of sulfuric acid.

At the End

Handling and using sulfuric acid can be quite a dangerous task that requires the user to be very careful.

You should always handle such corrosive acids with the proper protective equipment. Be sure to wear safety goggles, gloves, and the right attire to keep your skin safe in case of splashing.

Moreover, it would help if you read up on the right protocols to follow in case of a spill or accident. Never rush through the disposal process and consider all the precautions.

Despite being relatively safe in lower concentrations, you should still be careful and keep all chemical substances away from the reach of children.

Ensure no kids or pets are around when handling or disposing of the acid, and opt for an environment-friendly practice.

If you require further assistance on how to dispose of sulfuric acid, we are here to help! Feel free to reach out to our disposal experts.

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