A natural sunscreen creates a physical barrier between your skin and the sun and contains zinc oxide and titanium dioxide. It can feel heavy and dry on the skin, which is something to consider for those hot days. Chemical sunscreens use active ingredients to filter both UVA and UVB rays. These ingredients sit on the outer layer of the skin to provide protection and the molecules do not enter the bloodstream. They also don't feel heavy or leave a white film on the skin.
While the word 'chemical may sound scary, it's not. It simply describes how the ingredients function. They essentially absorb the rays and release them from the skin. Sunscreen ingredients are designed to sit on the outer layers of the skin in order to provide protection. The molecules are not designed to enter the bloodstream, nor are they able to penetrate deeply.