Waterproof sunscreen works by adding special ingredients that help the sunscreen stick to your skin and prevent it from washing off easily when exposed to water.
The Science Behind Waterproof Sunscreen
Manufacturers achieve waterproofing in sunscreen by including specific additional ingredients alongside the standard active ingredients that protect from UV rays. These extra components are crucial for maintaining protection during activities like swimming or sweating.
According to the provided information, a manufacturer will add additional ingredients to the active ingredients to make them waterproof. These ingredients serve a dual purpose:
- They grip the skin: This creates a more robust bond with your skin's surface, preventing the sunscreen from being easily dislodged by water or sweat.
- They make the sunscreen water-insoluble: This means the sunscreen formulation will not dissolve or mix with water, allowing it to remain intact on your skin rather than washing away.
An example of such an additional ingredient mentioned is cetyl octanoate. This ingredient, among others, contributes to the water-resistant properties of the sunscreen, ensuring it stays effective even after you've been in water.
In essence, waterproof sunscreens aren't truly impenetrable forever, but they are formulated to maintain their protective capabilities for a specified period (often indicated on the packaging as water-resistant for 40 or 80 minutes) while you are wet. The key is the inclusion of ingredients that enhance adherence and reduce solubility in water.
