Choosing a sunscreen with the optimal amount of “sun protection factor” (SPF) can be confusing, so let’s try to clear the subject. There are two types of sunscreens: chemical sunscreen and physical sunscreen. The difference is that chemical sun screen must be applied 30 minutes prior to being out, whereas physical sunscreen blocks it right away. People with reactions or allergies would most likely benefit from physical sunscreen although it would feel a bit “heavier” on the skin.
Everyone knows the damage that the sun causes (e.g. cancer, premature aging), but something you might not know is that ultra-violent (UV) rays are present in all weather conditions and reflect off water, sand concrete, and snow, bouncing right back on your skin! UV rays can even go through clouds, windows, and clothing.
The number of SPF reflect two things,
- What kind of broad spectrum are you getting, and;
- The frequency of re-application.
What the different ratings mean:
- Physical sun screen gives you 100 percent protection;
- SPF 50 covers 98 percent spectrum, SPF 30 covers 94 percent…;
- SPF 30 is going to be good for 300 minutes (5 hours) SPF 20 will be good for 200 minutes ( 3 hours)…;
So don’t think you are protected when you are using SPF 15/20, because it is not enough broad protection and you are most likely not re-applying your sunscreen at adequate intervals.