Sunscreen

My grandma always tells me to put on sunscreen to avoid damaging my skin. Without thinking, I always listen to her. But exactly how does sunscreen protect us from the sun and the harmful UV rays?

According to Scientific American.com, here on earth, we are exposed to UVB and UVA photons. UVB rays have shorter wavelengths so they don’t penetrate deep into you skin. They cause sunburn and skin cancer.

Huh? A Photon?

Before we move on, I would like to ask, “What is a Photon?”
According to Wikipedia, a Photon is. . . “an electromagnetic phenomena. It mediates electromagnetic interactions and makes up all forms of light”


UVA rays have longer wavelengths and penetrate into the deeper layers of your skin. UVA exposure can cause premature aging of the skin and immunological problems.

Scientific American compares sunscreen as acting like a “very thin bulletproof vest” that stops the UV photons before reaching and damaging the skin.
Sunscreen contains organic and inorganic ingredients. The organic molecules such as octyl methoxycinnamate (OMC) or oxybenzone (Everyday Mysteries) absorb the UV rays and dispels it as heat. The inorganic pigments such as zinc oxide or titanium oxide absorb, scatter and reflect the UV rays.
To be effective, a sunscreen product must have adequate amounts of these protective agents. The sunscreen must also be able to be spread evenly over the skin.

SPF?


All I knew about SPF before doing this blog is that the higher the SPF the better. I guess I didn’t have the whole story. . .
On sunscreen labels, SPF stands for Sun Protection Factor.
Sunscreen with higher SPF allows fewer photons that produce sunburn to strike your skin.
Scientific American gives an example of “a SPF 10 sunscreen allowing 10 out of every 100 photons to reach the skin and an SPF 20 product as allowing only 5 out of every 100 photons to reach the skin.”
Because SPF only refers to UVB rays and sunburn, there is also a possibility that a sunscreen product can have a high SPF but still allow UVA photons to reach the skin.
To ensure that UVA rays are also being blocked, the U.S. market requires that the product contains significant levels of zinc oxide, ayobenzone or titanium dioxide. So make sure you check that out before you buy sunscreen!



What about tanning beds?
The UV output is different from bed to bed. In general, tanning beds contains less UVB and more UVA than the natural sunlight. This causes less of a burn and more tanning. In the long run, tanning beds can take a toll on your skin and therefore does not make a safe option.