A new study into the effect water has on our skin has found that hard water damages our protective skin barrier, potentially contributing to the development of eczema, and that using a water softener can reduce the risk.

Researchers from the University of Sheffield and King’s College London have discovered that exposing the skin to hard water damages the skin barrier, which is our defence against outside threats such as bacteria or sunburn, and increases the sensitivity of the skin to potential irritants found in everyday wash products such as soap or washing powder.

The team of researchers examined whether removing the calcium and magnesium ions found in hard water using an ion-exchange water softener could mitigate the negative effects of hard water on the skin. They found that using a water softener reduces the harmful effects of surfactants, potentially decreasing the risk of developing eczema.

The new study, which Harvey Water Softeners was asked to fund, has been published in the Journal of Investigative Dermatology, and coincides with National Eczema Week (16 - 24 September 2017.)

Managing Director of Harvey Water Softeners, Martin Hurworth, said: “The link between hard water and eczema has been reported anecdotally for years - now for the first time there’s academic proof from this major new study. We were pleased to provide industry support to this study in the form of hard water samples and our twin-cylinder water softeners that provided the pure, softened water that was needed. Plumbers need to know this latest research for their customers.

“The results show that the softened water from our product could lower your risk of eczema by helping to protect the skin barrier from the harmful effects of soaps and shampoos. For people living with eczema or wanting to protect themselves and their family against it, this research shows that softened water could be the answer.”

Hard water contains high levels of calcium and magnesium ions that bind to surfactants such as sodium lauryl sulfate (SLS) and sodium lauryl ether sulfate (SLES) – which act as detergents or wetting agents – making them insoluble, so they precipitate onto the skin.

Skin pH is normally acidic but hard water has high alkalinity which means it can raise the skin surface pH. A shift towards alkaline pH disturbs the skin’s natural function as a physical barrier and leaves it prone to colonization by potentially pathogenic bacteria which can cause infection.

Lead author of the study, Dr Simon Danby from the University of Sheffield’s Department of Infection, Immunity and Cardiovascular Disease, said: “By damaging the skin barrier, washing with hard water may contribute to the development of eczema – a chronic skin condition characterised by an intensely itchy red rash.

“Patients with eczema are much more sensitive to the effects of hard water than people with healthy skin. This increase in sensitivity is associated with a genetic predisposition to a skin barrier defect brought about by mutations in the gene encoding filaggrin. Filaggrin is a structural protein important for the formation of our skin’s barrier to the outside environment. Up to half of all people with eczema carry a filaggrin gene.”

“This new study reveals the mechanism by which calcium and magnesium ions in hard water, surfactants, and filaggrin interact to damage the skin barrier unlocking new information about how exposure to hard water could potentially contribute to the development of eczema.”