ABC’s of UVA, UVB, and SPF!

Posted on October 9, 2011

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What’s the most important part of my daily skin care routine?
SUNSCREEN!

Why is it important?
Sunscreen helps protect our skin against UVA and UVB rays. These rays can cause premature aging, skin cancer, and other ugly skin damage. Don’t quote me on this, but I once heard that the sun’s harmful rays are responsible for 80% of skin aging. Even if this is an exaggeration… it makes a super important point. Sun damage is bad and sunscreen is our only defense.

What’s the difference between UVA and UVB rays?
Ultraviolet-a (UVA): UVA rays cause premature aging because they penetrate deeper into the skin.

  • UVA rays are the cause of wrinkles, sunspots, uneven skin tone and all things bad. Sunscreens labeled with SPF does NOT indicate protection from UVA rays!!!! Please make sure your sunscreen blocks both UVA and UVB rays (broad-spectrum protection). Now that you know, be sure to make sure all of your suncreens protect against both UVB and UVA rays!

Ultraviolet-b (UVB): These shorter wavelengths causes sun burn and skin cancer.

  • UVB protection is indicated by SPF.

What should I know about SPF?

The Sun Protection Factor (SPF) refers to the sunscreen’s ability to screen or block out the sun’s harmful UVB rays.

For example: With a SPF 15, you can be in the sun 15 times longer that you can without sunscreen before burning (remember SPF indicates protection against UVB which causes sun burns and skin cancer, not UVA). Knowing the difference between PA and SPF will be very helpful in making sure you’re fully protected.

Also, SPF protection does not increase proportionally with an increased SPF number.

For example: SPF of 2 will absorb 50% of ultraviolet radiation, but a SPF of 15 absorbs 93%… not 100%. A SPF of 34 absorbs 97%. So as you can see, it’s really important to wear at least a SPF of 15. I typically like to wear at least a SPF of 30 for daily, and something higher for a day at the beach.

When should I apply?
EVERYDAY!!!… Even if you’re indoors most of the day.

  • Apply 20 minutes before going out in the sun, and reapply every 2 hours.
  • If UVB and UVA rays can penetrate the skin, they can penetrate through clouds. So even if you’re in the shade or it’s a cloudy day… sunscreen is still needed.

How should I apply?
Most people don’t apply enough, so be sure to apply a generous amount. Instead of rubbing the sunscreen on, use dabbing motions to seal your skin under the sunscreen. Don’t forget your neck and hands… Your neck and hands are 2 areas that can give your age away without you even realizing it.

Which one do I use?

I don’t like to use moisturizers with sunscreen in them. In my mind… A moisturizer sunscreen combo is like a woven basket, with holes that rays can get through. I want a solid coat of moisturizer covered by a solid coat of sunscreen.  Also, most moisturizer sunscreen combos indicate SPF which protects against UVB rays… but leaves out UVA ray protection!

I currently am using Kiehl’s, which is a chemical sunscreen (scroll down to * for more details on ingredients). It’s nice and light on the skin, and not thick and pasty.

  • Active ingredients for UVA protection: Avobenzone, Oxybenzone
  • Active ingredients for UVB protection: Homosalate, Octisalate, Octocrylene

Important but FUN facts

  • The fairer your skin, the easier you’ll burn.
  • A typical shirt only offer SPF of 6.5. Darker clothes provide a little more protection than lighter clothes.

I hope you’ve enjoyed this post. I consider sunscreen one of the most important part of my skin care routine… If you haven’t been applying sunscreen, I hope this post encourages you to incorporate sunscreen into your daily routine!!!! You’re pretty skin will thank you :)


* Ps… just in case you’re interested in the ingredients…

There are 2 types of sunscreen ingredients: Chemical and Physical.

A chemical sunscreen ingredient absorbs sunlight. Some people are allergic to this type of sunscreen because it is actually absorbed into the skin. I recommend making sure you’re not allergic before purchasing.

UVA chemical ingredients

  • Avobenzone, Parsol 1789, Dioxybenzone (UVB, UVAII), Ecamsule, Menthyl Anthranilate, Meradimate, Oxybenzone (benzophenone, benzophenone-3), Sulisobenzone (UVB, UVAII).

UVB chemical ingredients

  • Aminobenzoic acid, Cinnamates (octyl methoxycinnamate (OMC), Ethylhexyl p-Methoxycinnamate, high incident of contact irritation, non comedogenic, widely used), Cinoxate, Dioxybenzone (UVB, UVAII), Ensulizole, Homosalate, Octocrylene, Octinoxate, Octisalate, Oxybenzone (UVB, UVAII), Octyl dimethyl paba, Padimate O, Para-aminobenzoic acid (PABA), Salicylates (octyl salicytate (OCS), high incident of contact irritation, widely used), Sulisobenzone (UVB, UVAII), Trolamine salicylate.

A physical ingredient actually sits on your skin to form a protective barrier. The ingredient absorbs the sunlight or simply reflect it back like a mirror!  Recommend physical ingredients for people with sensitive skin (won’t absorb into the skin) and children, but these tend to be a bit thicker in consistency.

  • Zinc oxide protects you from UVB and most of UVA
  • Titanium dioxide (oxide) protects you from UVB and short UVA radiation, but not long UVA which causes sun damage and aging.

Until next time! Bye!~

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