PHYSICAL SUNSCREENS contain active mineral ingredients, such as titanium dioxide or zinc oxide, which work by sitting on top of the skin to deflect and scatter damaging UV rays away from the skin. Titanium dioxide protects against UVB rays, but not the full spectrum of UVA rays. Zinc oxide protects against the entire spectrum of UVB and UVA rays.

CHEMICAL SUNSCREENS contain organic (carbon-based) compounds that create a chemical reaction and work by changing UV rays into heat and then releasing that heat from the skin. Must be applied directly onto the skin!