Here are the pros and cons of both:
Physical sunscreens, more commonly known as “mineral” sunscreens, begin to work immediately after applying, by creating a physical barrier (a reflective surface) on the skin. Most mineral sunscreens contain micronized zinc oxide or titanium oxide, two ingredients recognized as safe by the FDA and often recommended for people with sensitive skin and gentle enough for children. The downside they can be chalky, and difficult to spread. Many physical sunscreens now use micronized or non-nano zinc oxide (meaning they have smaller molecules), effectively reducing that white cast appearance.
Now let's discuss Chemical sunscreens ... firstly as opposed to physical sunscreens they don't sit on the skin and block rays. Instead, they feature active ingredients that absorb UV rays, like a sponge. Therefore, it needs to be applied 20-30 minutes before sun exposure to allow for adequate absorption to protect you from ultraviolet rays. For instance, when getting out of the water and immediately reapplying a chemical sunscreen one should seek shade for at least 20-30 minutes to allow for the chemical sunscreen to be effective. This is of course in stark contrast to physical sunscreens.
If you see ingredients like:
You are dealing with a chemical sunscreen. Most chemical sunscreen's do not leave a visible film layer and they are easier to apply. Because they are designed for absorption, they go on smoothly without feeling sticky or greasy.
People with sensitive skin may experience unwanted reactions.
So, which is better? There is no clear winner. The most effective sunscreen is the one you will use consistently.