What Happens If You Swim With Too Much Chlorine in Pool?




Indoors or out, public or privately owned, chances are that the pool you’re swimming in is cleaned and disinfected with chlorine. Maintaining proper chlorine levels requires careful measuring and testing. But what happens if you accidentally add too much chlorine in pool water? Is it still safe to swim?

It can be unsafe to swim in a pool with too much chlorine. It can cause skin, eye, and lung irritation. A safe level of chlorine, 1-5 ppm, should not cause health concerns, but extremely high levels of chlorine can be dangerous. Steps should be taken to reduce the chlorine level in the pool before swimming.

You may have thought you were properly maintaining your pool by adding chlorine regularly. But what happens when you accidentally add too much? How do you know if the pool has too much? Hint: you can’t tell by the smell. Knowing the proper chlorine levels can keep you safe during this fun summertime activity.

what is the highest chlorine level safe to swim in

What is the highest chlorine level safe to swim in?

Chlorine is a crucial element in maintaining the cleanliness and safety of swimming pools and spas. It acts as a disinfectant, eliminating harmful bacteria, viruses, and microorganisms that can cause health issues among swimmers.

However, while chlorine is essential for ensuring a clean and safe swimming environment, it’s important to manage its concentration to provide a pleasant and risk-free experience for swimmers.

According to safety guidelines, the chlorine level in swimming pools and spas should not exceed 4 parts per million (ppm). This upper limit is set to balance the need for effective disinfection without causing discomfort or potential harm to swimmers.

It is a threshold beyond which swimmers may experience irritating effects such as red, stinging eyes, itchy skin, and even respiratory discomfort.

Signs of too much chlorine in pool

If you go swimming with high chlorine in pool, it can affect your body in different ways. The higher the concentration of chlorine, the more severe your reaction may be.

Here are some symptoms of too much chlorine in pool:

  • Itchy, irritated eyes
  • Skin redness
  • Dry or itchy skin
  • Rash or hives
  • Asthma
  • Irritation to the respiratory tract

Chlorine poisoning

In rare instances, an extremely over-chlorinated pool may cause chlorine poisoning. Some signs to watch out for include:

  • Watery eyes and blurry vision
  • Coughing, wheezing, or difficulty breathing
  • Tightness or dull pain in the chest
  • Pain or burning in the eyes, nose, or throat
  • Nausea or vomiting

Most reactions to chlorine are mild and will disappear within a day. If you are in pain or discomfort, it may be smart to get checked out by a healthcare professional.

What chlorine level is too high to swim?

There are times you will need to raise the chlorine level higher than usual to super-chlorinate it. This process is done to remove algae, bacteria, and chloramine. When a pool is super-chlorinated, the chlorine level is raised to between 10 ppm and 20 ppm. These levels are unsafe to swim in and can burn or irritate your skin and eyes.

Is 20 ppm chlorine dangerous? Chlorine levels this high are definitely potentially dangerous to swim in. When the chlorine level is above the acceptable range of 4 ppm, it’s best to wait before swimming. 

Sometimes, waiting a short while is all that is needed for the chlorine level to drop down to a safer range. Other times, you may need to take steps to lower the level of chlorine before entering the pool again.

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How to lower chlorine in pool

If the chlorine level in your pool has become too high, you may need to work to bring the level down. There are several things you can do to fix an over chlorinated pool.

Stop chlorinating the pool

It may seem like common sense, but it is one thing for you to check. While you are trying to lower the level, make sure no sources are adding more chlorine. This includes salt cell chlorinators and floating chlorine dispensers.

Leave the pool uncovered

A bright sunny day can help to lower the level of chlorine quickly. The ultraviolet in sunlight breaks apart the chlorine and releases it. While the hot summer sun is a significant cause for needing more chlorine, you can use that to your advantage while trying to lower the level.

So if you have a solar pool cover then leave it off and after a few hours, test the water to measure the chlorine level.

Add water

Draining some of the water from your pool and adding fresh water can help dilute the amount of chlorine. This may work if your chlorine level is elevated only slightly. If it is very high, this may not be an option because of the amount of water needed.

Add chlorine neutralizer or other chemicals

If you are looking to reduce the chlorine level quickly, you can add chemicals to your pool to help. A chlorine neutralizer works effectively and rapidly. If the chlorine level is very high, you may need to add a second dose.

Common chlorine neutralizers are sodium thiosulfate and hydrogen peroxide.

Read my post How to lower chlorine levels in a pool for full details.

Wait until the chlorine level of your pool is safe again

After working to lower the level of chlorine in your pool, is the water safe?

Before entering the pool, be sure to test the water to ensure the chlorine is at an acceptable level. You may need to wait longer for the chlorine to reach a safer level

If you have added a chlorine neutralizer or other chemical, it is especially important to give it time to work. When your pool chlorine measures between 1 ppm and 5 ppm, it is safe for swimming again.

Can you be allergic to chlorine?

The good news is that you cannot be allergic to chlorine. However, you may be sensitive to it. Sensitivity is more likely to occur with longer-term exposure to chlorine. For example, lifeguards or competitive swimmers may develop skin sensitivity or have an increased risk of developing asthma.

Reducing your reaction to chlorine in your pool

There are ways to minimize or prevent your reaction to chlorinated water.

  • Rinse it off!
    After swimming, be sure to shower to rinse the chlorine off your skin.
  • Nourish dry skin.
    Moisturizer can also help prevent dry or irritated skin. 
  • Protect your hair.
    Rinsing your hair will decrease dryness and help stop it from turning green.
  • Wear goggles.
    If the pool water irritates your eyes, wearing goggles may help. After swimming, try some saline or lubricating eye drops to rinse the chlorine from them.
Reducing your reaction to chlorine in your pool - wear googles

Safeguarding your eyes from exposure to chlorine and removing any traces of it from your body post-swim are important steps in reducing potential reactions. 

Importance of testing chlorine levels in your pool

If you own a pool, you know the importance of testing the water regularly. Checking the water is the only way to know if it has the proper chlorine level. There are signs, such as the water color or smell, that let you know your pool needs some chemicals added. But without testing, there is no way to know the exact levels. 

Strong pool smell

A pool that smells like chlorine may have you wondering if it has been over-chlorinated. 

In fact, the opposite is true. What you are smelling is not chlorine, but a chemical compound called chloramine. Chloramine occurs from a mixture of chlorine with sweat, dirt, or urine from swimmers. Unhygienic behavior – such as peeing in the pool or not showering first – causes the available chlorine to be used up quickly. Proper hygiene is critical for maintaining a healthy pool.

If you can smell the chlorine in a pool, it is a sign that the water could need more chlorine, not less. 

Adding more chlorine will eliminate the chlorinates that cause the smell. A properly maintained pool should have no odor at all.

Safe levels of chlorine

Chlorine works to disinfect the water in the pool. It keeps us safe by killing many types of germs. But in order to work, the proper amount of chlorine is needed. Use either a liquid test kit or test strips to help determine the amount of chlorine in your pool.

Besides chlorine, test kits and strips will determine other levels in your pool. A pool is balanced when all are within their proper levels.

ChemicalIdeal RangeAcceptable Range
Chlorine2-4 ppm1-5 ppm
Total Alkalinity80-100 ppm60-120 ppm
Calcium Hardness200-400 ppm150-1000 ppm

Is 20 ppm chlorine dangerous in a pool?

20ppm is definitely much too high a chlorine level to swim in as the level should be no higher than 4ppm.

Is 10 ppm chlorine safe to swim in?

10ppm is definitely much too high a chlorine level to swim in as the level should be no higher than 4ppm.

What to do if chlorine is too high in pool?

You should:
Stop adding any more chlorine until the level has dropped
Do not cover the pool to allow sunlight to dissipate the chlorine
Partially drain and add new water
Use Chlorine neutralizer