You probably don't think much about what's in your shower water. It comes out warm, it rinses off soap, and that's about it. But if you're on a municipal water supply - which covers most households in Australia and New Zealand - your water is treated with chlorine. And while chlorine does its job well (it kills bacteria and keeps water safe to drink), what it does once it hits your skin and hair is a different story.
Chlorine Is an Oxidiser - And That Matters for Your Skin
Chlorine's effectiveness as a disinfectant comes from the same property that makes it hard on your body: it's a strong oxidising agent. When it contacts the skin during a shower, it starts breaking down the acid mantle - the thin, slightly acidic film of natural oils that sits on the surface of your skin and acts as a protective barrier.
Once that barrier is disrupted, moisture escapes more easily, a process dermatologists measure as transepidermal water loss (TEWL). Research published in the Journal of Allergy and Clinical Immunology found that among 1,303 three-month-old infants, those living in areas with higher domestic chlorine concentrations showed significantly elevated rates of skin barrier dysfunction, measured directly through TEWL (Perkin et al., 2016). Infants in the highest combined water hardness and chlorine group had an 87% increased likelihood of atopic dermatitis compared to those in the lowest group.
That study focused on infants, but the mechanism - chlorine degrading the skin barrier - applies to adults too. A separate study using hairless mice exposed to chlorine-rich water over 90 days found measurable increases in oxidative stress markers, including inflammatory cytokines, alongside reductions in skin moisture and elasticity (Lee et al., 2023).
In short, daily chlorine exposure, at the concentrations found in standard tap water, can make your skin drier, more reactive, and slower to hold onto moisture.
What It Does to Your Hair
Hair is made largely of keratin, a structural protein. Chlorine oxidises keratin, weakening the protein bonds that give hair its strength and flexibility. Laboratory studies using chlorinating agents on human hair samples confirmed oxidation of keratin and physical structural damage to the hair shaft (Martz et al., 2022). Separate research has shown that chlorinated water increases hair porosity over time, allowing moisture to leak out more easily and making hair more susceptible to damage and colour fade (Luginbühl et al., 2018; Morini et al., 2017).
For anyone with colour-treated hair, this is particularly relevant. Chlorine is an oxidising bleach - the same basic chemistry used in hair lighteners - so regular exposure gradually strips artificial pigment and can cause dyed hair to look dull or brassy faster than it should.
Day to day, this shows up as frizz (the cuticle can't lie flat when it's damaged), brittleness, split ends, and that dry, straw-like texture after showering that no conditioner seems to fully fix.
The Inhalation Side of Showering
Here's the part that often gets overlooked: hot water causes chlorine to vaporise. In a small, enclosed bathroom, this creates a concentrated steam environment. Research published in the American Journal of Public Health found that inhalation during showering can result in greater exposure to chloroform (a chlorine disinfection byproduct, or THM) than drinking the same water, because the lungs absorb volatile compounds directly into the bloodstream without the filtration of the digestive system (Weisel & Jo, 1996).
This doesn't mean your shower is making you ill. For most healthy adults, the effects are subtle. But for people with asthma, respiratory sensitivity, or young children, repeated chlorine vapour exposure is worth taking seriously.
What Actually Filters Chlorine at the Showerhead
Water pitcher filters, under-sink systems, or refrigerator filters don't help here - they only treat drinking water. To reduce chlorine exposure during a shower, filtration needs to happen at the showerhead.
Effective shower filtration typically uses one or more of the following:
- KDF-55 (a copper-zinc redox medium) - neutralises free chlorine through an electrochemical reaction
- Activated carbon - adsorbs chlorine and some organic compounds
- Calcium sulfite - neutralises both chlorine and chloramine (the alternative disinfectant used by many water utilities)
- Vitamin C (ascorbic acid) - rapidly neutralises both chlorine and chloramine on contact
The PuraRush filtered showerhead by HydroFiltrr uses VC Carbon Fiber filtration - a premium activated carbon-based filter media - to reduce chlorine and other contaminants before the water reaches your skin and hair. Beyond filtration, it also includes a pressure boost, meaning you don't sacrifice water pressure for cleaner water.
If you've been dealing with dry skin after showering, dull or frizzy hair that doesn't respond to products, or a scalp that feels itchy or irritated, your water quality is a reasonable place to look. It's one of those things that's easy to overlook because it happens gradually, every single day.
The Bottom Line
Chlorine is in your water for good reason. But by the time it reaches your shower, the bacteria it was fighting are long gone - and what's left is a daily chemical exposure that can quietly degrade your skin barrier, damage your hair proteins, and fill your bathroom air with disinfection byproducts.
Filtering it out at the showerhead is a straightforward fix. And once you've showered without it for a week or two, you'll notice the difference.