The Long-Term Impact of Chlorine Exposure
Chlorine is everywhere - in steam, surfaces, and sunscreen reactions - and even brief exposures can inflame lungs, disrupt your thyroid, and weaken your skin.
STORY AT-A-GLANCE
Chlorine exposure from pools, tap water and cleaning products creates toxic byproducts like chloramines that damage skin, lungs and eyes, with effects building up over time
Even low-level chlorine exposure causes respiratory issues, skin irritation and is linked to increased cancer risk
Chlorine reacts with chemical sunscreens to create hormone-disrupting compounds, while also stripping protective oils from skin and hair during swimming
Pre-swimming protection includes applying barrier moisturizers like pure lanolin, rinsing with clean water beforehand and wearing protective swimwear to reduce chlorine absorption
Installing whole-house water filters, using saltwater pools instead of chlorinated ones and immediate post-swim showering significantly reduce harmful chlorine exposure
Everywhere you turn, chlorine is part of your environment, quietly embedded in your drinking water, shower steam, pool systems and the cleaning products under your sink. It's praised for its germ-killing power and assumed to be harmless in small doses. But your body tells a different story.
From the outside, chlorine looks like it's doing its job: disinfecting, sanitizing, sterilizing. But inside your body, it's interacting with delicate tissues in ways that compromise cellular function, disrupt hormones and irritate your lungs and skin. You might brush off a sore throat after scrubbing a bathroom or chalk up itchy skin to "pool chemicals," but these are early warning signs, not minor inconveniences.
People who work around chlorine, like lifeguards, janitors and health care staff, often don't realize that daily exposure builds up. Even casual swimmers and children experience side effects that seem unrelated at first, from chronic cough to recurring skin rashes. And if you're not using proper protection, even your household tap water and cleaning routine could be silently wearing down your body's defenses.
Understanding where chlorine exposure happens, how it affects different tissues and what habits make it worse is the first step to protecting your health. What you'll see next are the overlooked, underreported ways this chemical impacts your body — and what to do about it before the damage becomes permanent.
Chlorine Disrupts Your Skin, Lungs, and Hormones
Chlorine exposure triggers multiple forms of irritation, even at low levels. This goes far beyond just dry skin. Chlorine doesn't stay stable in water. Instead, it reacts with organic materials like sweat, skin cells and urine to form toxic byproducts such as chloramines and trihalomethanes, which your body absorbs through your skin or inhales during swimming.1
These chemical byproducts damage your lungs and increase asthma risk — Indoor pools are a particular problem. Chloramines accumulate in the air when ventilation is poor, making you breathe them in deeply with every stroke.
These airborne toxins irritate your airways and increase your risk of asthma and a condition called reactive airways dysfunction syndrome (RADS), a type of asthma. The telltale "chlorine smell" is actually a warning sign that chloramines are likely present at dangerous levels.
Even brief exposure to pool water increases your chance of eye irritation — A study found that swimming for more than 15 minutes increases your risk of eye irritation by 2.8 times.2 If chlorine levels are over 0.4 parts per million (ppm) — which is within legally accepted levels — the risk jumps 4.6 times.3 These effects are caused by chlorine stripping away the protective tear film on your eyes, leading to symptoms like redness, burning and blurry vision.
Your hair and skin take a hit after every swim — Chlorine disrupts the lipid layer that protects your skin from dryness and inflammation. For people with eczema or sensitive skin, this effect is even worse. One study found that chlorine concentrations as low as 0.5 ppm worsened inflammation and reduced the skin's water-holding ability.4 The result is more itching, redness and even flares of eczema or pool-related dermatitis.
Your hair isn't immune either — chlorine wrecks it. Chlorine binds to hair proteins like keratin and dissolves the natural sebum that keeps your hair strong and shiny.5 This leaves strands brittle, dry and prone to breakage and split ends. Blonde hair is especially vulnerable, often turning green due to the oxidation of copper in pool water.
Chlorine reacts with sunscreen to create hormone-disrupting toxins — Here's where the danger takes a more serious turn. Chlorine reacts with avobenzone — a common ingredient in chemical sunscreens — creating chlorinated phenols and acetylbenzene compounds.6 These are linked to hormone disruption and liver damage.7
Chloramines, not chlorine, are the true villains, and they're harder to avoid — While chlorine itself is a strong disinfectant, it's the compounds formed when it reacts with organic matter that pose the greatest risk. These secondary byproducts are more likely to be inhaled or absorbed, and they don't dissipate quickly — especially in indoor pools with stagnant air. This makes repeated exposure far more damaging than most people realize.
Chlorine Is Toxic at the Cellular Level
According to the Toxicological Profile for Chlorine from the Agency for Toxic Substances and Disease Registry (ATSDR), chlorine is classified as a highly reactive and corrosive gas that damages tissue on contact.8
Even short bursts of high exposure cause immediate injury to your respiratory tract. For people working in water treatment, public sanitation, pool maintenance or chemical manufacturing, the risk is especially dangerous, although even swimming or bathing in chlorinated water poses a risk.
The harm from everyday low-dose exposure builds up over time and is linked to cancer — The report emphasizes that long-term chlorine exposure doesn't need to be extreme to cause damage.
Even low-level, repeated contact — whether through inhalation or skin — has been linked to chronic bronchitis, asthma and permanent changes in lung function. Over time, it contributes to reduced oxygen uptake, fatigue and inflammation-driven tissue changes that don't just resolve on their own.
Hospital janitors, gym staff, university maintenance crews and those working in sewage or water treatment are among the most at-risk groups.9 Unlike people who choose to swim, these workers often handle chlorine directly, clean with it or breathe it in from treated surfaces and air systems without adequate protection. Long-term exposure, even in small doses, has been tied to chronic breathing problems, skin damage and even cancer.10
Chlorine reacts instantly with moist tissues in your eyes, mouth and lungs — When inhaled, chlorine immediately reacts with the water in your mucous membranes, forming hydrochloric and hypochlorous acids — both corrosive and damaging to delicate lung tissue. This chemical interaction causes burning sensations, coughing, chest tightness and, in some cases, delayed-onset breathing difficulties.
Your airways are the first line of damage, and the last to fully recover — The ATSDR notes that damage often begins in your upper airways, with irritation of your nose and throat, then spreads to the tiny air sacs where oxygen exchange happens. Even if symptoms improve temporarily, the underlying damage often leaves you vulnerable to long-term conditions like RADS or fibrosis, which permanently impair lung elasticity and function.
And even low-concentration exposure rewires how your lungs respond to air. According to toxicological data, people exposed to chlorine consistently show hypersensitive airway responses, meaning their lungs overreact to even small irritants like dust or cold air. This creates a vicious cycle of inflammation, swelling and narrowing of airways that mimics asthma, but without any allergic trigger.
Unlike many pollutants, chlorine doesn't just enter your body; it creates new toxins inside it — Chlorine doesn't float passively through your system. Once inhaled or absorbed, it chemically transforms into new compounds that inflict further cellular damage.
The ATSDR confirms that these secondary toxicants trigger oxidative stress, overwhelm antioxidant defenses, and damage cell membranes and mitochondrial DNA — leading to energy loss and inflammatory cascades.
The most severe cases occur when chlorine is mixed with other common chemicals — A key risk outlined in the report involves household or industrial settings where chlorine is accidentally mixed with ammonia or acidic cleaners. This produces chloramine gas, an even more dangerous compound that causes rapid onset respiratory failure. In this case, what starts as routine cleaning instantly becomes a medical emergency.
Many people clean their homes with bleach-based products in closed spaces like bathrooms or kitchens. Without fans or open windows, that gas accumulates quickly. Breathing it in regularly contributes to the same types of damage seen in workers in chemical-heavy industries.11
Simple Swim Habits That Protect Your Skin from Chlorine Damage
Coach Slava Fattakhov, a former professional swimmer and coach, published a step-by-step skin protection guide on his website designed for swimmers, families and anyone regularly exposed to pool water.12 His goal is clear: help people swim often without sacrificing their health. The guide outlines clear, simple routines that reduce chlorine's drying and irritating effects before, during and after swimming.
Hydrating your skin before swimming makes it less absorbent to pool chemicals — Coach Slava recommends rinsing your body with clean, chlorine-free water before entering the pool — not just for hygiene, but to protect your skin. This initial rinse saturates your skin cells with clean moisture, making it harder for chlorinated water to absorb deeper into your pores. It's a small habit that reduces chemical exposure every time you swim.
Using a barrier cream or natural oil like pure lanolin helps seal in moisture — Applying a layer of protection before swimming is key. Simple oils like pure lanolin or coconut act as a physical shield between your skin and the water. These oils slow down chlorine's ability to strip away your natural oils.
Clothing matters — covering up limits the damage — The guide encourages swimmers to wear long-sleeved rash guards or full-coverage swimwear. This cuts down the amount of skin directly exposed to chlorinated water. For children and those with eczema-prone skin, this simple swap is one of the most effective, passive ways to prevent irritation.
Getting chlorine off quickly is one of the most important steps — Right after your swim, rinse thoroughly with fresh water. Chlorine keeps reacting with your skin even after you leave the pool, so washing it off immediately stops that process in its tracks. The sooner you rinse, the less chance chlorine has to break down your skin barrier.
Locking in moisture after your swim speeds up recovery — Post-shower, apply a thick, nourishing moisturizer while your skin is still damp. The best moisturizer is pure lanolin, as it helps restore your skin's barrier function and retain hydration. This is especially important for frequent swimmers or anyone with dry or aging skin.
Stay hydrated inside and out to maintain healthy skin — Internal hydration matters too. Drinking pure, filtered water before and after swimming improves your skin's resilience from the inside, helping it hold up better against chemical exposure. Even mild dehydration makes your skin more reactive to irritants.
Simple Ways to Protect Your Body from Chlorine Exposure
If chlorine exposure is drying out your skin, interfering with your breathing or making your eyes sting every time you swim, it's time to change your routine. Whether you're a swimmer, a parent of water-loving children or someone working around chlorinated environments, these steps will help you take control.
Your body wasn't designed to process this kind of chemical assault on a regular basis, but you're not helpless. You just need a smarter strategy. Here's what I recommend to start reversing the damage and limiting future exposure.
Switch to a saltwater pool or skip indoor pools entirely — Chlorine exposure hits hardest when it's concentrated and trapped, like in a steamy indoor pool. That "chlorine smell" is actually toxic chloramines building up in the air. Saltwater systems use far less chlorine and don't produce the same harsh byproducts. If you have the option, outdoor saltwater pools are a much safer choice for your lungs, skin and eyes.
Apply pure lanolin as a pre-swim skin barrier — If you're going to be in chlorinated water, coat your skin with pure lanolin first. It's one of the only moisturizers that creates a thick, natural barrier without irritating sensitive skin. Use the liquid form for larger areas or the solid balm for elbows, hands and feet. This step locks in moisture and blocks chlorine from leaching into your skin.
Install a whole-house water filter to eliminate chlorine at home — You're not just exposed to chlorine in pools; it's in your shower and tap water too. A high-quality whole-house filtration system removes chlorine before it reaches your skin or lungs. This matters more than you think.
Inhaling chlorine steam during hot showers is one of the fastest ways it enters your bloodstream. You'll notice less dryness, fewer breathing issues and softer skin within days of switching. It's important to remove chlorine from your drinking water as well, as disinfection byproducts in tap water are linked to an increased risk of cancer.13
Rinse off before and after swimming — Always rinse with clean, fresh water before getting into the pool. Hydrated skin absorbs less chlorine. After you're done, shower immediately using a natural, fragrance-free cleanser. Then moisturize while your skin is still damp to lock in hydration. This two-step rinse routine reduces chlorine's contact time and minimizes its damaging effects.
Avoid chemical sunscreens — Chlorine reacts with certain sunscreen ingredients like avobenzone and oxybenzone, creating hormone-disrupting byproducts. Find shade or use clothing to cover your skin when you need to limit sun exposure.
FAQs About Chlorine Exposure
Q: What are the long-term effects of chlorine exposure?
A: Long-term exposure to chlorine damages your lungs, skin and eyes. It increases your risk for conditions like asthma, bronchitis and skin disorders such as eczema and contact dermatitis. Chlorine also reacts with other substances, forming toxic byproducts that disrupt hormones, are linked to cancer and irritate sensitive tissues.
Q: Where does chlorine exposure commonly happen?
A: Most people encounter chlorine through swimming pools, tap water, household cleaning products and workplaces like hospitals, gyms and water treatment facilities. Indoor pools and poorly ventilated cleaning areas are especially risky because toxic gases like chloramines build up in the air.
Q: How does chlorine harm my body at the cellular level?
A: Once chlorine contacts moist tissues in your eyes, lungs or skin, it forms corrosive acids that inflame and damage cells. It also triggers oxidative stress, breaking down cell membranes and disrupting mitochondrial energy production. Repeated exposure worsens inflammation and slows healing.
Q: What steps can I take to protect myself from chlorine?
A: Use pure lanolin as a barrier on your skin before swimming. Shower with filtered water and moisturize immediately after. Avoid chemical sunscreens and use a whole-house water filter to remove chlorine from your drinking water and shower. Whenever possible, choose saltwater pools or swim outdoors, and avoid mixing chlorine-based cleaners with other products.
Q: Who is most at risk for chlorine-related health issues?
A: People working in sanitation, pool maintenance, hospitals and gyms face the highest risks, along with frequent swimmers and children. Anyone exposed to chlorine regularly, especially in poorly ventilated environments, should take steps to minimize contact and support skin, lung and overall health.
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What about chlorine dioxide?