"Perhaps the best approach to stabilizing avobenzone is to incorporate octocrylene (EU) in the formulation to help prevent the formation of the triplet state. Octocrylene is also a globally approved sunscreen (although some evidence suggests octocrylene may itself be a photo-sensitizer, causing indirect DNA damage). The key L’Oreal patents (in the United States) for stabilization of avobenzone using octocrylene expired in late 2014 and are now freely available."
An oil-soluble chemical sunscreen agent that protects skin in the UVB and somewhat in the UVA II range with a peak absorption of 304 nm. Its protection is not strong enough on its own but it is quite photostable (loses 10% of SPF protection in 95 mins) and is often used to stabilize other photo-unstable UV-filters, for example, Avobenzone. It is also often used to improve the water resistance of the products.
Octocrylene's safety profile is generally quite good, though a review study in Contact Dermatitis reports an "increasing number of patients with photo contact allergy to octocrylene." Mainly adults with ketoprofen-sensitivity and children with sensitive skin are affected, so if you have a small kid, it is probably better to use octocrylene-free sunscreens.
Not coral reefs and marine life friendly! Belongs to the HEL list of ingredients to avoid while purchasing SPF to protect the marine environment:
The HEL LIST includes:
Any form of microplastic sphere or beads.
Any nanoparticles like zinc oxide or titanium dioxide.
Para-aminobenzoic acid (PABA)