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.

This ingredient is an emollient, solvent, and texture enhancer. It is considered a skin-softener by helping the skin prevent moisture loss.

It helps thicken a product's formula and makes it easier to spread by dissolving clumping compounds.

Madecassic Acid is a major component of Centella Asiatica Extract. It has anti-inflammatory and antioxidant properties.

It is a triterpenoid, meaning it naturally acts as an antioxidant. Antioxidants protect your skin against damage from environmental factors such as pollution and UV.

Pentylene glycol is typically used within a product to thicken it. It also adds a smooth, soft, and moisturizing feel to the product. It is naturally found in plants such as sugar beets.

The hydrophilic trait of Pentylene Glycol makes it a humectant. As a humectant, Pentylene Glycol helps draw moisture from the air to your skin. This can help keep your skin hydrated.

Polyacrylate Crosspolymer-6 is a texture enhancer and pH adjuster.

It is be used to thicken water-based products and create a gel-texture with a velvet feel.

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

It’s often used to:

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.