The short answer is yes, you can safely swim in a pool with 10 ppm chlorine. 10 ppm (parts per million) is within the recommended chlorine range for pools. However, there are some important factors to consider when swimming in chlorinated water.
What is the Recommended Chlorine Level for Pools?
The Centers for Disease Control and Prevention (CDC) recommends keeping pool chlorine levels between 1-3 ppm for residential pools and 2-10 ppm for public pools. The ideal chlorine range helps kill germs and bacteria that can cause recreational water illnesses like diarrhea, swimmer’s ear, and skin infections.
Here are the recommended chlorine levels for pools according to the CDC:
| Pool Type | Recommended Chlorine Level (ppm) |
|---|---|
| Residential | 1-3 |
| Public/Community | 2-10 |
10 ppm falls within the safe range for public pools. However, it is on the higher end and residential pools are usually kept closer to 2-4 ppm.
Is 10 ppm Chlorine Too Much?
10 ppm chlorine is not necessarily too much for a public pool. However, any level over 3 ppm may start to cause minor irritation for some swimmers.
According to the World Health Organization (WHO), irritant effects of chlorine in pool water may start to occur at levels above 3 ppm. Effects may include:
- Mild eye irritation
- Dry, itchy skin
- Minor nose and throat irritation
These effects are temporary and subside once you leave the pool. However, people with sensitivities may experience more irritation at 10 ppm.
Factors That Increase Chlorine Irritation
Several factors can make chlorine irritation more likely, even at recommended levels:
- Length of exposure – Irritation is more likely with longer swimming times.
- Inadequate showering – Not showering before swimming leaves chlorine-reactive contaminants on your skin.
- Poor water circulation – Stagnant water builds up chloramines that irritate eyes.
- Low pH – Acidic water (pH under 7) causes more chlorine fumes that irritate airways.
- Individual sensitivities – People with asthma or allergies are more reactive to chlorine.
Well-maintained pools circulates and filters the water to prevent buildup of irritants. Showering thoroughly before swimming removes contaminants on your body that react with chlorine. These best practices reduce irritation risk.
Tips to Prevent Chlorine Irritation
Here are some tips to prevent irritation if swimming in a 10 ppm chlorine pool:
- Shower before entering the pool
- Wear goggles to protect eyes
- Limit swimming time to 30 minutes or less
- Rinse off in the shower after getting out
- Moisturize your skin after swimming
- Avoid pools if you have asthma or allergies
Is 10 ppm Chlorine Safe for Kids?
10 ppm chlorine is generally safe for kids to swim in. Young children are often more sensitive to chlorine irritation. However, pools keep chlorine levels at the lower end of the recommended range when young kids are present.
Here are some tips for kids swimming in 10 ppm chlorine pools:
- Use swim diapers for infants/toddlers
- Shower before and after swimming
- Apply moisturizer after swimming
- Provide goggles and swim caps
- Limit swim times to 10-15 minutes
- Watch kids for signs of irritation
Most kids adapt well to chlorinated water. But if a child experiences stinging eyes, coughing, or scratchy throat, shorten swim times or try a different pool.
How Does Chlorine Level Vary Throughout the Day?
Chlorine levels will fluctuate throughout the day in a public pool. Levels tend to be lowest in the mornings before opening. Chlorine dissipates as swimmers enter the pool. Pools typically close midday to boost chlorine back up to proper levels.
Here is a rough guideline of how chlorine levels progress during a typical public pool day:
| Time | Chlorine Level (ppm) |
|---|---|
| Opening (8-9 AM) | Around 5 ppm |
| Mid-morning (10 AM) | 3-5 ppm |
| Lunchtime peak (11AM – 1 PM) | 2-3 ppm |
| Closure for boosting (1-3 PM) | Less than 1 ppm |
| Re-opening (after 3 PM) | 5-10 ppm |
Pools try to maintain closer to 10 ppm when crowds are lower, such as opening and closing times. Midday when the pool is busiest, levels drop closer to the minimum of 2 ppm.
How Often Should Pool Chlorine Levels be Checked?
Pool chlorine levels should be checked multiple times per day. Commercial pools are required to document chlorine readings every 2-4 hours.
Typical public pool guidelines for checking chlorine levels include:
- Before opening
- Every 2 hours while open
- After adding more chlorine
- Before and after peak use times
- At closing
Pool test kits make it easy for staff to check chlorine levels. Results are recorded in a pool logbook. Reviewing records lets staff make sure levels are always in the ideal range.
How is Chlorine Added?
Sodium hypochlorite solution is the most common chlorine additive used at pools. Calcium hypochlorite tablets are also used in automatic dispensers.
The pool maintenance staff adds chlorine in the pump room as needed to maintain proper levels. More chlorine is added:
- In the morning before opening
- During midday closure
- At closing time
- Anytime tests show low chlorine
Well-run commercial pools have staff monitoring and adjusting chlorine multiple times daily.
What Issues May Occur if Chlorine is Too High?
Allowing the chlorine level to get too high can cause problems. Potential issues with excessive chlorine include:
- Eye and skin irritation
- Difficulty breathing
- Damage to swimsuits/towels
- Corrosion of metal fixtures
- Breach of safe regulations
Pools with chlorine above 10 ppm will likely receive complaints of irritation or be forced to close until lowering the level. A commercial pool could face fines or closure if inspectors find the chlorine exceeds 10 ppm.
Can High Chlorine Make You Sick?
High chlorine levels do not increase the risk of infectious diseases. However, the irritation effects may cause headaches, sore throat, coughing, or nausea in some people.
People with asthma or respiratory issues are more likely to experience breathing problems from high chlorine exposure. Seeking medical care is recommended if you have difficulty breathing after swimming in a heavily chlorinated pool.
Frequently Asked Questions
Why does chlorine smell stronger some days?
Chlorine has a stronger smell when the pH is lower. Pool staff may occasionally adjust pH downward, causing a chlorine spike. The smell should go away in a few hours once the pH rises back up.
Is chloride the same as chlorine in pools?
No, chloride and chlorine refer to different chemicals. Pool chlorine levels measure the amount of hypochlorous acid used as a disinfectant. Chloride is simply an element found in small amounts in pool water.
Can too much chlorine turn hair green?
No, copper pipes and minerals turn hair green, not chlorine. This myth comes from the fact that pools with improper pH and low chlorine often have a green tint.
Do chlorine pools dry out your skin?
Yes, dry skin is common after swimming in chlorinated water. The chlorine strips away protective oils. Be sure to apply moisturizer soon after leaving the pool.
Is 10 ppm chlorine too much for hot tubs?
Yes, 10 ppm is too high for hot tubs. The ideal range is 2-5 ppm for hot tubs. Higher temperatures cause chlorine to dissipate faster, so less is needed.
The Bottom Line
Swimming in a 10 ppm chlorine pool is safe for most people. Minor irritation may occur, especially with longer exposure times. Limiting swim sessions and showering properly can help reduce any bothersome effects.
Pools keep chlorine at the high end of 10 ppm when crowds are lower. During peak use times, levels are maintained closer to the 2 ppm minimum. Pool staff check and adjust chlorine levels multiple times daily to keep swimmers healthy and comfortable.
