First Aid Beauty Weightless Liquid Mineral Sunscreen With Zinc Oxide SPF 30 Versus Sephora Collection Daily Mineral Sunscreen Cream SPF 30 - USA

Polyhydroxystearic Acid is a soft wax made from castor oil.

It is is a texture thickener, emulsifier, and film-former. Emulsifiers prevent ingredients from separating, such as oils and waters.

Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin. 

It’s often used to:

Silica is a mineral naturally found in our skin. It helps to thicken and smooth the texture of a product. It also acts as an agent for other ingredients by increasing the absorption of other ingredients into the skin.

Silica is often used for absorption and can help reduce shine when products are applied. Silica occurs in naturally in materials like clay and sandstone, and it can also be produced synthetically.

Tocopherol (also known as Vitamin E) is a common antioxidant used to help protect the skin from free-radicals and strengthen the skin barrier. It's also fat soluble - this means our skin is great at absorbing it.

Vitamin E also helps keep your natural skin lipids healthy. Your lipid skin barrier naturally consists of lipids, ceramides, and fatty acids. Vitamin E offers extra protection for your skin’s lipid barrier, keeping your skin healthy and nourished.

Trisodium Ethylenediamine Disuccinate is used to help stabilize a product.

It is a chelating agent, meaning it helps prevent metal ions from binding to other ingredients. This prevents unwanted reactions in products. Metal ions can come into a product via the water ingredient. They are found in trace amounts and are not known to be harmful.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

Zinc Oxide is a mineral broad-spectrum UV filter; it is the broadest UVA and UVB reflector approved by the FDA. While it is most commonly man-made for cosmetics, it can naturally occur in zincite, a rare mineral.

Today, traditional and nano-sized zinc oxide can be found in beauty products. Nano-sized zinc oxide can enhance a product's UV protection. While it is not believed to have a negative effect on skin, nano-zinc oxide may be harmful to coral reefs - though the verdict is not entirely out on this one.