How sunscreen works

and why sunscreen is so vital to skincare

When you’re at the beach—or just stepping out for coffee on your lunch break—the sun’s invisible rays are constantly beating down, even through a cloudy day. Ultraviolet (UV) radiation is what gives us a tan and also damages our DNA, which in worse cases leads to skin cancer.
 
There are two types of UV rays to be concerned about:

• UVB, which causes sunburn and some types of cancer
• UVA, which can penetrate more deeply into the skin and cause age spots, premature wrinkling and some skin cancers.

 
Sunscreens are one of our first—and best—defenses against the sun. Sunscreens are made of different mixes of chemicals. The first type of sunscreen (inorganic chemicals such as zinc oxide or titanium dioxide) physically block sunlight by scattering it away from your skin like an umbrella.
 
Think of the white strips—like paint!--you used to see on people’s noses back in the day. Because these inorganic chemicals deflect sunlight, they deflect both UVA and UVB rays.
 
Now, many manufacturers use smaller inorganic particles mixed with organic, carbon-based lotions that absorb the UV radiation instead of our cells. Organic chemicals, with names such as avobenzone or oxybenzone absorb UVB radiation through their chemical bonds.
 
SPF, which stands for “Sun Protection Factor” is specifically referring to how well the lotion protects against over 90 percent of UVB (not UVA, though some sunscreens claim they provide a broad-spectrum block against both, probably because of the inorganic materials reflecting sunrays away from you).

For example, SPF 30 prevents you from burning about 30 times longer than your usual time of burning.

So of course, even with the same application of sunscreen, individuals will have varying responses and requirements for protecting their skin. In any case, standard recommendations are to reapply within two hours and wear a hat and sunglasses if you’re out for a long time.
 
Most experts recommend using sunscreen with an SPF between 15 and 50. Surprisingly, SPFs above 50 have not shown to be more effective, so don’t spend the extra money on a higher rating.
 
No matter which SPF you chose, a daily sunscreen is incredibly important for your face, even if you aren’t at the beach.

Remember, sunscreen is the single most important thing you can do to help your skin age healthfully and gracefully!

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