Hard Water and Face Washing: What We Know, What to Do

The USGS describes water hardness as the amount of dissolved calcium and magnesium in the water. As rain soaks into the ground and moves through soil and rock, it dissolves small amounts of naturally occurring minerals and carries them into the groundwater, and that is where hardness comes from. The CGWB's Annual Ground Water Quality Report 2024 also notes that calcium is the most abundant cation in India's groundwater, and that the type of rock making up an aquifer affects hardness. In other words, hardness can vary by area and by water source.

The BIS drinking water standard, IS 10500:2012, sets an acceptable limit for total hardness (as calcium carbonate) of 200 mg per litre, and allows up to 600 mg only when no alternative source is available. These figures are for drinking water, not values set with skin in mind. For reference, the USGS classes water at 60 mg per litre or less as soft and above 180 mg as very hard. It says hardness itself is not a health concern, but it can be a nuisance in daily life.

Observational studies from the UK, Japan, Spain and Denmark have reported a link between living in a hard water area and a higher rate of atopic eczema in children. The protocol for the SOFTER trial, published in BMJ Open in 2019, summarises these studies. Observational studies, though, only show that two things occur together. On their own, they do not show that hard water is the cause.

A 2018 study by Danby and colleagues in the Journal of Investigative Dermatology washed the skin of 80 people with the surfactant sodium lauryl sulfate in water of different hardness and compared the results. Areas washed with hard water kept more surfactant on the skin, and showed more water loss through the skin and more irritation. These changes were more marked in people with atopic eczema who also carried filaggrin gene mutations. Because the results come from controlled experimental conditions, they cannot simply be carried over to everyday face washing.

There have also been randomised trials of changing the water. The UK SWET trial, published in PLOS Medicine in 2011, randomised 336 children with moderate or more severe atopic eczema to receive either a household water softener plus usual care or usual care alone, with the primary assessment at 12 weeks, and found no added benefit over usual care in eczema severity. The SOFTER pilot trial, published in 2022, tested installing a softener before a baby was born. It was not designed to judge whether softeners work, and its conclusion was that a full trial would be feasible. In short, there are hints that hard water may affect skin, but these trials have not shown that installing a household water softener improves or prevents atopic eczema in children. They did not look at face washing on its own.

If changing your water is not practical, you can start with how you wash. The AAD advises wetting your face with lukewarm water and applying a gentle cleanser that does not contain alcohol with your fingertips. It says tools such as washcloths and mesh sponges can irritate the skin, and so can scrubbing. It also advises limiting face washing to twice a day and after sweating.

Rinse with lukewarm water too, and pat your face dry with a soft towel. If your skin is dry or itchy, the AAD suggests applying a moisturiser next. Since the Danby study looked at surfactant left on the skin after rinsing, HANARI suggests rinsing thoroughly so that no lather is left behind. There is no evidence, though, that rinsing for longer removes the effects of hard water. This note is general information, not medical advice. If tightness, redness or itching after washing keeps coming back, see a dermatologist.

The USGS explains that soap does not lather well in hard water, that calcium in the water reacts with soap to form soap scum, and that your hands may feel as if a film is left on them after washing. These signs can give you a rough idea, but only a test will give you an actual number.

If you use a piped supply, you can ask your local water utility or municipal water department for water quality information. For bore well water, you can take a sample to a water testing laboratory. In a 2024 statement, India's Ministry of Jal Shakti said states have opened water quality testing laboratories to the general public to test their water samples at a nominal rate. Look for 'total hardness (as CaCO3, mg/L)' on the report and compare it with the figures above. A home test kit can give a rough reading, but if you need an accurate value, it is better to go by a laboratory result.

HANARI's Clean Start Gel Cleanser is a gel cleanser for the step before serum and moisturiser. Post-wash tightness and residue are still to be confirmed in finished-product use testing. It uses a mixed surfactant system that includes amino acid-derived surfactants, and it is not an amino acid-only formula. Ingredient names alone do not prove mildness.

There is no basis for saying this cleanser removes minerals from water or reduces the effects of hard water, and HANARI does not say so. It is planned to launch in December 2026 and is not on sale yet. Once it is available, follow the directions on the product, and if your skin reacts in a way that bothers you, stop using it and see a dermatologist.