The correct use of sunscreen
NPR's Short Wave podcast had a recent episode on mistakes people make using sunscreen and I learned a few things.
Pay attention to expiration date
The active ingredients can degrade, and bacteria can get into the creams, too. Several dermatologists interviewed said that each season they throw out the old, buy new.
There's also a lot more zinc oxide products available now that go on much clearer.
Unlike the old days when zinc oxide was an opaque paste.
High SPF isn't that important
A sunscreen with an SPF of 15 will block out 93% of the UV rays. And when you bump it up to SPF 30, you're blocking out about 97%. So Dr. Oyesanya says the sunscreens with the highest sun protection factor, like the 80s or the hundreds, aren't necessarily better.
Make sure to apply enough
A shot glass full of sunscreen is for the whole body (if you're going swimming). And then about a teaspoon for the face.
Reapply sunscreen every couple of hours
If you're exposed to the water, even with sunscreens labeled as water-resistant, you're really only getting about 80 to 90 minutes of protection.
Don't skip cloudy days
You're still getting about 80% of the UV rays filtered through those clouds on a cloudy day.
Do not keep it in the glove compartment of your car.
The sunscreen is actually being degraded by heat.