>>4769214>putting on extra sunscreenWhich is full of metals typically not used in biological processes. Current medical consensus has an odd divide between skin and outside environment. Although it protects from the outside environment, it also absorbs all sorts of stuff coming in contact to it. That's where they will find their error.
Since sunscreen is a skin contact item, skin must be seen as a sponge rather than an impermeable layer. Given many ingredients in sunscreen are designed to last a very long time with high SPF ratings (that wildly vary), that means that it can't wash off easily. It also can't streak either, and many consumers prefer aerosolized product, which includes smaller compounds. It will absorb into the skin very easily.
That's just asking for trouble. There are few organ systems we willingly abuse more than the skin unless they're a raging alcoholic or a druggie, so it's a general high risk that I believe is well known but not disclosed to the public to have those ingredients in sunscreen.
Now if they find out how to make hippo sunscreen (they literally sweat sunscreen), I'll eat my words. However, it sweats red and it's proven difficult to synthesize. Hippos are also very poor research specimens due to their provisional needs and extreme aggression.