Ingredients to Make Sunscreen Waterproof

To make sunscreen waterproof, you need to add film-forming polymers. These polymers create a protective layer on the skin that helps the sunscreen resist washing off when exposed to water or sweat. The choice of polymer often depends on the type of sunscreen formula (e.g., water-based or oil/silicone-based).

Here are some types of film-forming polymers commonly used for waterproofing in sunscreens, based on the products found:

• Acrylates/Octylacrylamide Copolymer: This type of polymer, like WaterGuard™ Spray, is often soluble in alcohol and is effective for creating a waterproof film, especially in spray formulations.
• Acrylates/Ethylhexyl Acrylate Copolymer (and) Acrylates/Dimethylaminoethyl Methacrylate Copolymer: Polymers such as Syntran 5778 are water-dispersed film formers that provide long-lasting and waterproof properties.
• Styrene/Acrylates Copolymer (and) Ethylene/Acrylic Acid Copolymer: Similar to the above, Syntran 5288 is a water-dispersed film former suitable for waterproof applications.
• Trimethylsiloxysilicate: Often used in combination with silicones like Cyclopentasiloxane (Silicone Film (Soft Film, Low Viscosity, Cyclopentasiloxane Base)), this creates a durable, waterproof film, commonly used in long-wear makeup and sunscreens.
• VP/Eicosene Copolymer: This oil-soluble film former provides a solid film texture for waterproofing and can also help boost SPF.
• Polyurethane-35: UV35 is a water-dispersible film former specifically designed to enhance water resistance and boost SPF values while being gentle on the skin.
• Acrylates/C12-22 Alkyl Methacrylate Copolymer: Allianz OPT is a polymer film former that provides water and wear resistance, suitable for various sunscreen formulas including low viscosity emulsions and sprays.
• Hydrogenated Polycyclopentadiene: Used in bases like Isododecane (Hydrogenated Polycyclopentadiene (Isododecane Base)), this oil film polymer helps create a long-lasting, waterproof coating.

By incorporating these film-forming agents into your sunscreen formulation at the recommended usage rates, you can achieve the desired level of water resistance.