Polyester-8

This ingredient is also known as Polycrylene. It is a UV photostabilizer and often used in sunscreens as an alternative to octocrylene.

Polycrylene is used to stabilize other UV filters, especially avobenzone, which is known to degrade rapidly without stabilizers. It also absorbs UVB light, but is only about 1/3 as effective as octocrylene.

At its maximum recommended strength of 4%, this ingredient is not likely to make a significant contribution to SPF factor. Polycrylene has a large molecular weight so it's unlikely to penetrate skin.

Although rare, this ingredient can cause contact dermatitis.

Due to regulatory loopholes, you'll be able to find this chemical UV filter in "100% mineral" sunscreens.