Thursday, April 26, 2012

Have fun in the sun!


I have been researching on sunblocks, sunscreens, ultraviolet rays and such and I found information which would be good to share with everyone!! A reason for this research is because it will be related to the next post coming up! So... I have came across two pages that summarized almost everything I wanted to know. Contents on this blog post are from here and here!

Try this pop quiz!

  1. Do sunscreens provide better UVA protection than UVB protection?
  2. Is SPF 45 sunscreen three times stronger than SPF 15 sunscreen? Does it last three times longer?
  3. What works better, sunscreens or sunblocks?
  4. Do "broad-spectrum" sunscreens protect against all UV rays?

If you are not sure of the answers... I was once like you. Hahaha. But I do know what SPF is, because I go on frequent fishing trips with boyfriend and out of curiousity I went to google the differences between the SPF number.


I usually hear of UVA and UVB but I have absolutely no idea of what they are and whats the difference. I shall do away with all the technical terms and explain in layman terms!

UVB (ultraviolet-B) are short-wave solar rays that is usually the culprit behind sun-burnt skin. They are more potent than UVA in producing sunburns and these rays could only penetrate at epidermis / dermis level of your skin. They do not significantly penetrates glass, but at reflective surfaces such as snow or ice, UVB rays can bounce back by 80% so they hit the skin twice!

UVA (ultraviolet-A) are in turn the long- wave solar rays. Although they are less likely to cause sunburn than UVB, UVA penetrates the skin more deeply into the subcutaneous layer of the skin (as seen above) and they are the chief culprit behind wrinkles. Studies have also shown that UVA not only increases UVB 's cancer-causing effects, but may directly cause some skin cancers, including melanomas. They can even penetrate clouds and glass! Photobucket This is why sunscreens are important even though it seems like a cloudy day..

I usually only have SPF 25 BB Cream on my face and a spray on SPF 50 sunscreen only on days when I'm out swimming or fishing.

What SPF tells you is the length of time the sunscreen can protect your skin from reddening! But then again it's hard to know how long it takes to suffer from sun burnt because sometimes reddening only appears some time later after I get burnt! So I'll take the time it takes for me to feel the prickly sensation on my skin..

So lets say it takes 10 minutes for me to get red from the sun without protection... using an SPF 15 sunscreen theoretically prevents reddening 15 times longer -- about 5 hours! But to maintain the SPF, I usually reapply sunscreen around 2 hours later or so.

SPF is not an amount of protection per se and hence a sunscreen of SPF 45 does not means it is 3 times stronger than a SPF 15 product.

The Skin Cancer Foundation recommends SPF's of at least 15, which block 93 percent of UVB. While SPF's higher than 30 block only 4 percent more UVB, they may be advisable for sun-sensitive individuals, skin cancer patients, and people at high risk of developing skin cancer. They also allow some margin for error if too little sunscreen is applied.

Difference between sunscreen and sunblock?
Sunscreens chemically absorb UV rays, sunblocks physically deflect them. So what is the difference between doing it chemically and physically?

There are currently 17 active ingredients approved by the FDA for use in sunscreens. These filters fall into two broad categories: chemical and physical. Most UV filters are chemical: They form a thin, protective film on the surface of the skin and absorb the UV radiation before it penetrates the skin. The physical sunscreens are insoluble particles that reflect UV away from the skin. Most sunscreens contain a mixture of chemical and physical active ingredients.

And speaking about Broad-Spectrum Sunscreens, it indicates that a product shields against UVA as well as UVB. It does not guarantee protection against all UVA wavelengths, however. Most broad-spectrum sunscreens and sunblocks with an SPF of 15 or higher do a good job against UVB and short UVA rays; if they also contain avobenzone, zinc oxide, or titanium dioxide, they should be effective against the entire UVA spectrum.



And here is the list of FDA - Approved Sunscreens! Quite fun to take out my sunscreens to find out which ingredients were used and what rays do they provide protection from.

One last tip is to keep away from the sun between 10am and 4pm!! And I always thought that the morning sun until 11am would be able to provide me natural Vitamin D. Photobucket


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