Water is a great solvent. It’s neutral and doesn’t provide any strong positive or negative effects. It just helps components to mix better and to transport active components.
C12-15 Alkyl Benzoate is mostly used as formulation component. It gives the product a soft and silky but non-greasy feeling. As for the skin benefits, it's an emollient – it makes the skin softer and more hydrated. It also helps to kill bacteria and increase the product’s shelf life.
Butylene Glycol is a very popular synthetic alcohol. It helps the product to absorb deeper and faster. It is also a solvent for other ingredients. As for the skin benefits, it helps to attract water and helps to make the skin softer.
Unlike many other “Glycols”, it is not harmful and that's why it is used in many products. It was approved by US FDA and US EPA for usage.
Citric Acid is one of the AHAs and it is a super useful component! It’s a great antioxidant. It acts as a soft peeling that removes dead cells and kills bacteria. It becomes even more effective if used with other cosmetic acids. Combined formulations are more active, but can irritate sensitive skin if used too often. The component can also whiten the skin and remove dark areas.
It's an exfoliator, meaning it increases UV sensitivity of your skin. That's why it's very important to use sunscreen after it.