Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:

Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.

Caprylyl Glycol is a humectant and emollient, meaning it attracts and preserves moisture.

It is a common ingredient in many products, especially those designed to hydrate skin. The primary benefits are retaining moisture, skin softening, and promoting a healthy skin barrier.

Carbomer is a polymer of acrylic acid. Its main role is to create a gel consistency.

A high amount of carbomer can cause pilling or balling up of products. Don't worry, most products contain 1% or less of carbomer.

Disodium EDTA plays a role in making products more stable by aiding other preservatives.

It is a chelating agent, meaning it neutralizes metal ions that may be found in a product.

Ethylhexyl Salicylate is an organic compound used to block UV rays. It primarily absorbs UVB rays but offers a small amount of UVA protection as well.

Commonly found in sunscreens, Ethylhexyl Salicylate is created from salicylic acid and 2-ethylhexanol. You might know salicylic acid as the effective acne fighter ingredient and BHA.

Ethylhexylglycerin (we can't pronounce this either) is commonly used as a preservative and skin softener. It is derived from glyceryl.

You might see Ethylhexylglycerin often paired with other preservatives such as phenoxyethanol. Ethylhexylglycerin has been found to increase the effectiveness of these other preservatives.

Homosalate is a chemical sunscreen filter that provides protection in the UV-B range (280nm - 320 nm), with a peak protection at 306 nm. It is internationally approved for use in sunscreens.

Homosalate is not photo-stable, meaning it's strength as a UV filter degrades over time with exposure to the sun. Because of this, it's often used in combination with other chemical sunscreen filters as avobenzone (which protects from the UV-A range). Homosalate also helps act as a solvent for harder-to-dissolve UV filters.

Parfum is a catch-all term for an ingredient or more that is used to give a scent to products.

Also called "fragrance", this ingredient can be a blend of hundreds of chemicals or plant oils. This means every product with "fragrance" or "parfum" in the ingredients list is a different mixture.

Phenoxyethanol is a preservative that has germicide, antimicrobial, and aromatic properties. Studies show that phenoxyethanol can prevent microbial growth. By itself, it has a scent that is similar to that of a rose.

It's often used in formulations along with Caprylyl Glycol to preserve the shelf life of products.

Potassium hydroxide is commonly known as caustic potash. It is used to fix the pH of a product or as a cleaning agent in soap. In cleansers, it is used for the saponification of oils.

Sapnification is the process of creating fatty acid metal salts from triglycerides and a strong base. During this process, Potassium Hydroxide is used up and is not present in the final product.

Silica, also known as silicon dioxide, is a naturally occurring mineral. It is used as a fine, spherical, and porous powder in cosmetics.

Though it has exfoliant properties, the function of silica varies depending on the product.

Tocopheryl Acetate is AKA Vitamin E. It is an antioxidant and protects your skin from free radicals. Free radicals damage the skin by breaking down collagen.

One study found using Tocopheryl Acetate with Vitamin C decreased the number of sunburned cells.

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.