Does your skin feel tight, dry or itchy after showering? Then it makes sense to look at the water. Limescale can play a part, but it's rarely the only cause. In this guide Besjaar sets out what research says about hard water and dry skin, what's a myth and what really helps.
What does limescale in your water do to your skin?
Hard water contains a lot of calcium and magnesium. These minerals react with soap and shampoo. As a result, soap lathers less and is harder to rinse off, and a thin film of soap residue stays on your skin.
In 2018, researchers from the University of Sheffield and King's College London looked at exactly this effect. They washed volunteers' skin with a common foaming agent (sodium lauryl sulfate, SLS) in water of different hardness. After washing with hard water, clearly more SLS stayed on the skin. That residue led to more moisture loss through the skin and more irritation, especially in people with eczema and an inherited weaker skin barrier. With softened water the effect was smaller.
Two caveats: it was a short laboratory test, and the study was funded by a water softener manufacturer. It shows how limescale can irritate sensitive skin, but it doesn't prove that softening water solves skin complaints.
Does hard water cause eczema?
Eczema is somewhat more common in hard water areas. But a link isn't the same as a cause. That became clear in the Softened Water Eczema Trial, a British study of 336 children with moderate to severe eczema, all living in hard water areas. Half had a water softener installed at home, the other half didn't. Eczema improved in both groups. The researchers concluded that the water softener gave no extra benefit on top of usual care.
Do you have eczema or persistent itching? Then your GP or a dermatologist is the right place to go. No shower head or filter replaces treatment.
How hard is the water in the Netherlands?
The British studies looked at really hard water: at least 200 milligrams of limescale per litre, just over 11 °dH. Most Dutch water companies soften their water centrally. As a result, Dutch tap water is soft on average, around 8 °dH. In Groningen, Zeeland and Limburg it's somewhat harder. Find out how hard yours is in our guide to water hardness by province.
For most people in the Netherlands, limescale is at most one of the factors. The other causes are often more important.
Other causes of dry skin after showering
- Hot water. Hot water washes away your skin's natural oily layer faster.
- Long showers. The longer your skin is wet, the more moisture and oil you lose.
- Soap. Ordinary soap is alkaline, while your skin is naturally slightly acidic. A lot of soap disturbs that balance.
- The season. In winter the air indoors and outdoors is drier, and your skin reacts to that.
- Age. Older skin produces less sebum and dries out faster.
What does help?
- Shower lukewarm and short. Five to ten minutes is enough. A warm rather than hot shower spares your skin, and your energy bill.
- Choose a mild body wash. A soap-free, fragrance-free product is gentler on your skin. Use it mainly where it's needed.
- Rinse thoroughly. Take a few extra seconds to rinse off all soap residue. That residue is exactly what matters with hard water.
- Pat dry and moisturise. Don't rub, but pat your skin dry with a towel. Apply a rich cream within a few minutes, while your skin is still slightly damp.
- Don't expect softer water from a shower head with a filter. A filter holds back loose particles from the pipes and breaks down free chlorine, but dissolved limescale passes straight through. It isn't a treatment either. A filter mainly makes sense where tap water is chlorinated, as in Belgium, France and Spain. Read the honest story in shower filter: worth it or not? or take a look at the Besjaar Shower Head with Filter.
- Skin still dry or itchy? Then see your GP. Dry skin can have other causes too.
Frequently asked questions
Can limescale in your water cause dry skin?
It can play a part. With hard water, more soap residue stays on your skin, and that can irritate and dry it out. Hot water, long showers and soap usually have a bigger effect.
Does a shower filter help against dry skin?
Not against limescale: dissolved limescale passes straight through. A shower filter does hold back loose particles and break down free chlorine, which can matter if your tap water is chlorinated. It isn't a medical treatment: short, lukewarm showers and moisturising well help more.
Does hard water cause eczema?
That hasn't been proven. Hard water can irritate sensitive skin more. But in a large study, a water softener gave children with eczema no extra improvement.
Besjaar makes shower heads and filters for Dutch bathrooms, from Assen. Better water, every day.
Sources
- Danby et al. (2018) – The effect of water hardness on surfactant deposition after washing and subsequent skin irritation, Journal of Investigative Dermatology
- Thomas et al. (2011) – A randomised controlled trial of ion-exchange water softeners for the treatment of eczema in children
- Anna Ziekenhuis – Skin care and ointment advice (in Dutch)