Is tap water bad for your skin and hair?
Interest in preventive healthcare has increased in the last couple of years and with this, people are starting to look into the impact of chlorinated and hard water on the skin and hair. How does chlorine and hard water impact the skin, what is the science behind this and what kind of water filters are proven to work?
In this blog post we tackle these questions and provide insights on how to choose the right water filter for home. For a short answer, jump straight to the conclusion.
Why the skin?
The skin is the largest organ of the body, and it fulfils many functions.
- A barrier function, to protect the body from the environment
- A temperature regulator
- An immune organ, to detect infections
- A sensory organ, to detect temperature, touch, and vibration
Therefore it’s pretty natural that it’s also the most exposed to problems. Skin diseases affect around 23 to 33% of the population at any given time, and are the most common reason for people to consult their doctor when a new problem arises. Non-clinical dry and irritated skin and hair affect to even more people.
Consequently, skin and hair care is a huge industry. And big money attracts both honest and dishonest companies and individuals.
So what are the facts related to how tap water impacts the skin?
First of all, we don’t need scientific studies to show that chlorinated and hard water impacts people with sensitive skin. Compare showering in hard chlorinated water with soft less chlorinated water and most people immediately notice the difference. But are there any other proven negative effects?
Scientifically, it’s been difficult to prove causality on a larger scale, as there are so many factors that impact the skin. However, in recent studies comparing post / zip codes in the UK and US found that hard water increases the risk of developing eczema – a painful skin complaint affecting one in five people.
The condition causes red, itchy, inflamed, cracked and sore skin and can be exacerbated by a number of factors, including stress, chemical detergents, soaps and perfumes as well as diet and food.
It is most common in babies, affecting at least 10% of infants at some stage. Although it often disappears in childhood, it can carry into adult life.
Dermatologists and the NHS now recognise hard water is a common trigger for exacerbating eczema. However, many other studies such as this from UK show no or very limited impact from hard or chlorinated water: http://dwi.defra.gov.uk/research/completed-research/reports/dwi70-2-257.pdf
An area which water scientists do take very seriously though is THMs. When chlorine combines with organic compounds, such as the sweat and oil on our skin, it may produce trihalomethane byproducts, commonly referred to as THMs. The levels of THMs produced when you take a hot bath or shower are rather low, however, over time, these carcinogens could have increasingly detrimental effects. Read more here.
Some research has even associated chlorine with heart defects and other medical conditions for infants. See 2002 study published in the journal Environmental Research here.
Companies and influencers promoting water filters also make the following claims, although we have not found any research or studies to back them up:
- The skin absorbs the chlorine and other contaminants from the tap water, effectively poisoning the body
- Chlorinated water accelerates the aging process, similar to the effects of extended exposure to the sun
- Chlorinated water can deplete the skin of its natural oils that hold moisture in, leading to dry and itchy skin
- Chlorine not only kills the bad bacteria that can make us sick, but it also kills good bacteria on which our our skin relies.
What kind of filters protect the skin and hair from possible negative impacts of tap water?
This is where science is of great help, because there’s a huge gap between different types of filters. Some bluntly do nothing to improve the water while others are very effective in removing certain substances, such as chlorine.
First of all, only trust filters that have an independent lab testing or certification showing effectiveness and what they filter. In Europe and the EU, certified water lab is a great quality stamp whereas for the US, NSF is the best.
Secondly, most shower filters last 2-6 months. If they claim to last longer, then make sure that this is included in the test results.
Thirdly, there’s only one technology that has been proven to work directly in the shower and that’s KDF. KDF-55 is the most efficient filtering technology to remove chlorine and water-soluble heavy metals from high pressure hot tap water. It is to be noted that since KDF is a rather expensive patented technology, some companies mix it up with other compounds such as activated carbon. Make sure you know the proportion of the different compounds that make up a filter before purchasing.
Scientifically speaking, none of the shower filters soften the water. For people with sensitive skin removing chlorine does however provide a softening experience. However, for real water softening a whole house filter system will be required. More about this here.
Other methods such as Vitamin C and activated carbon may work as a complement but not on their own. Other substances such as e.g. magnetic or black stones have no scientific proof nor other evidence that they work.
Your local tap water may cause dry and irritated skin and hair or eczema. If this is the case, then a shower filter such as TAPP 1s can help.
When choosing a water filter make sure it:
- Has independent lab tests in Europe or NSF certification in the US
- Uses a proven filtering technology a such as KDF
- Provides realistic time frame for how long it lasts (typically 2-6 months)
And once you have a water filter installed, replace it as frequently as suggested or even more if you shower a lot.
Hopefully, this will help you find a reliable solution for better skin and hair. Enjoy!
US Department of Health & Human Services