This ingredient was banned in Hawaii because it has been shown to cause harm to coral reefs.2 Not exactly a ringing endorsement for something to be smeared all over your body. Aside from that, it is a form of synthetic estrogen, according to the Environmental Working Group, and can disrupt your hormones. In its review of sunscreen ingredients, the EWG found oxybenzone to be the most troubling ingredient.
These are the main ingredients that are killing off our ocean animals and cause skin cancer. Skin Cancer is leading cancer in the entire world.
Like the oxybenzone mentioned above, octinoxate is also banned in Hawaii for coral reef reasons.2 It has been shown to cause skin allergies, and in animal studies, it had effects on the reproductive system and thyroid.3
While this ingredient has not been found to cause hormone disruption like the others, the EWG did find that it causes high rates of irritation.3 And it is not sun-stable, which means it has to be mixed with stabilizers, like Octisalate (which the EWG ranks as having moderate toxicity concerns) to be used in sunblock.
4 Sunscreen Ingredients to Avoid – Byrdie. https://www.byrdie.com/sunscreen-ingredients-to-avoid