The pH scale measures how acidic or alkaline a substance is on a scale of 0-14. The higher the number, the lower the acidity. Skin is mildly acidic, with a pH value around 5. Eucerin’s 24h Deodorant Sensitive Skin Roll-On also has a pH of 5 and helps to maintain skin’s natural balance. This supports skin’s barrier function making it more resistant to external irritants and reducing sensitivity.