The skin is made up of 3 main layers and the skin's barrier, also known as the acid mantle, which protects the skin against bacteria, viruses, pollution and dehydration. This acid mantle is composed of the stratum corneum and the hydrolipid film. Where the stratum corneum protects the dermis layer of skin from trans epidermal water loss and external factors, the hydrolipid film is the key to the skin's protective barrier. This film is a thin, oily acidic layer mainly made of sweat, water, sebum, and other lipids. Should this layer get damaged, the acid mantle is broken, and the skin barrier becomes vulnerable to infections, dryness, dehydration, inflammation, and irritation.