Facial sprays are not new to the personal care industry, but have experienced a resurgence of popularity over the past several years. Many rely on water as an ingredient to boost skin moisture—the effects of which are seemingly substantiated in research claiming that fine water sprays can moisten skin to ultimately improve barrier function.
Aichi Medical University researchers sprayed three sizes of water particles—below 0.5 μm in condition A, 1.8 μm in condition B and 5.4 μm in condition C—on the faces of 17 healthy adult women aged 30-46 years. All particles were smaller than the intercellular spaces of the stratum corneum in order to better permeate the skin; additionally, water was not charged, meaning it did not pass through an electric device such as a humidifier.
Testing took place in a climate-controlled chamber in February in order to capture the mists' effects on dry winter skin. Skin conductance, transepidermal water loss (TEWL) and skin elasticity at the cheek were used as metrics to measure barrier function.
Researchers found condition A—in which water particles were smallest—best able to permeate the skin's epidermal layer to its dermal layer. This fine spray was also found to improve water retention function to last up to 360 min after spraying due to its noncharged nature and small size.
The research was published in Skin Research and Technology.