Chemical sunscreens vs. physical blocker sunscreens
Regardless of which type of sun protection you choose, there are benefits to regular use. Numerous studies that have shown that regular use of sunscreen has anti-aging effects. In a recent study in Australia, researchers compared skin aging in 900 men and women from Australia over the course of four years. They found that those that used sunscreen daily, had an undetectable increase in skin aging.
According to the FDA, sunblock with SPF 30 is the safest way to go. Anything above SPF 30 is not usually necessary as it has little incremental benefit and below 30 is not effective enough.
Physical sunscreens: use physical UV filters by deflecting or blocking the sun’s rays. Suggested for those with heat sensitive skin (like those with rosacea and redness) since it deflects the heat and energy given off by the sun away from the skin, as well as those who are acne-prone as they seem to be less likely to be pore-clogging. Common physical sunscreen ingredients include titanium dioxide (TiO2) and zinc oxide (ZnO)– these are both broad spectrum protectors, meaning they protect against both UVA and UVB rays
Pros: Physical sunscreens tend to be better tolerated by most skin types because they are not absorbed in the skin.
Cons: Physical sunscreens tend to leave a white cast or white streaks after application and don’t offer as much UVA protection compared to chemical sunscreens. Physical sunscreens are also a bit thicker so they may be more difficult to apply.
Chemical sunscreens: Chemical sunscreens work by absorbing the sun’s rays so that the skin doesn’t absorb the rays. Some chemical filters can scatter sun rays, but still mostly just absorb them. Common broad spectrum filters used include oxybenzone, octinoxate, avobenzone, and homosalate.
Pros: Pros include its ability to defend the deeper layers of skin-including collagen fibers and other tissue-against the aging effects of UVA rays; and it prevents penetration by the UVB rays responsible for tanning and sunburn.
Cons: Rubs off more easily and must be frequently reapplied.
Since they each have their pros and cons, many of today’s sunscreens contain both physical and chemical UV filters.