Octocrylene
Octocrylene is an oil-soluble chemical sunscreen agent (CAS #6197-30-4) that absorbs UV radiation primarily in the UVB range and somewhat in the UVA II range, with a peak absorption of 304 nm. It is a substituted acrylate ester (2-Cyano-3,3-Diphenyl Acrylic Acid 2-Ethylhexyl Ester) and is subject to EU Cosmetic Restrictions VI/10. Its UV protection is not considered strong enough on its own, but it is notably photostable, losing only about 10% of SPF protection in 95 minutes. It is commonly used in formulations to stabilize other photo-unstable UV filters such as Avobenzone and to improve product water resistance.
Octocrylene provides UVB and partial UVA II protection and is valued primarily for its photostabilizing effect on other UV filters, particularly Avobenzone. It also contributes to the water resistance of sunscreen formulations.
A review study in Contact Dermatitis reports an increasing number of patients with photo contact allergy to octocrylene. Adults with ketoprofen sensitivity and children with sensitive skin are particularly affected; octocrylene-free sunscreens are recommended for young children.
