Buy sunscreen with SPF 30 or Higher
The American Academy of Dermatology recommends using sunscreen with sun protection factor (SPF) of 30 or higher. Sun protection factor references the amount of time a sunscreen protects you from sunburning UVB rays compared to unprotected skin. For example, if it takes your skin 10 minutes to burn in the sun without any sunscreen, applying a sunscreen with SPF 30 will protect you 30 times longer before sun burning (roughly 300 minutes or 5 hours).
Buy sunscreen that has Broad Spectrum coverage
There are 2 types of ultraviolet rays we talk about when it comes to sunscreens: UVA and UVB. UVB rays are primarily responsible for reddening the skin and sunburn while UVA rays penetrate deeper in the skin and impact aging and wrinkling. Both rays are harmful and damaging to the skin so it is recommended to buy a sunscreen with broad spectrum coverage.
Buy sunscreen that states water resistance up to 40 or 80 minutes
The Food and Drug Administration (FDA) now requires all sunscreens (in the US) to provide this information on its labeling. The product must state whether it is water resistant up to 40 or 80 minutes while sweating or in water. Sunscreen products can no longer use the words waterproof or sweat proof on its labeling.
Check the expiration date
Make sure the sunscreen you buy doesn’t have a close coming expiration date. You want to buy a product that allows a season or 2 of use, but really the tube shouldn’t last you longer than that. Sunscreen products left in the medicine cabinet sitting can reduce its effectiveness depending how it’s stored. Extreme temperatures and light can affect the product’s effectiveness.