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Thu Jun 14, 2007 10:51 am  |
Got this one from Lifescript.com
UV Basics
Hale explains the difference between the two harmful types of UV rays:
UVA rays: Reach deep into the skin, leading to premature aging
UVB rays: Pass just below the skin’s surface, causing sunburn
Both UVA and UVB rays contribute to the development of skin cancer. A third type, UVC rays, are filtered out by the ozone layer and don’t reach the earth’s surface.
A sunscreen’s SPF refers only to the amount of protection offered from UVB rays. Another rating system, PFA, is able to measure the percentage of UVA rays that are blocked; it is still being reviewed by the Food and Drug Administration (FDA).
“There is no way to communicate to the consumer how much UVA protection a sunscreen offers,” says dermatologist Dr. James Spencer, a renowned skin cancer expert. “A formula can merely indicate the presence of UVA protection.”
To shield yourself from both types of rays, look for a label that reads “broad-spectrum protection,” Spencer says. This means that the formula protects against both UVA and UVB rays – though not necessarily equally.
All sunscreens will shield you from UVB rays. The following ingredients protect against UVA rays: Mexoryl, oxybenzone, titanium dioxide, zinc oxide, and avobenzone (also known as Parsol 1789).
SPF Basics
Logic tells us that a sunscreen with SPF 30 is twice as good as SPF 15, but this isn’t the case.
According to The Skin Cancer Foundation, SPF 15 blocks out 93% of UVB rays, while SPF 30 blocks 97% of the rays. However, many patients don’t use the sunscreen correctly, thus decreasing a formula’s effectiveness by as much as half.
While choosing an adequate SPF is important, “the most important thing is the frequency of application,” Spencer says.
Apply an adequate amount of sunscreen before sun exposure and make sure to reapply every two hours. It doesn’t matter how good your formula is if it never makes it out of the bottle. “If it’s not present, it can’t protect you,” Spencer says.
Both our doctors recommend a broad-spectrum sunscreen with an SPF of at least 15 applied daily – not just when you’re sunbathing. “I use a broad-spectrum sunscreen every day, and I always reapply – even when it’s cloudy or raining,” Hale says.
If you stay indoors all day, you might think you’re safe, but take a look around you. Are you by a window? Although glass blocks UVB rays, it doesn’t block UVA.
What’s New?
Ecamsule, better known as Mexoryl, is an agent that filters out short-wave UVA rays. (Other UVA-blocking sunscreens only protect against longer-wave UVA rays.) One of the most effective UVA-blocking chemicals, Mexoryl, has been available in Europe for over a decade and just recently received FDA approval for use in the United States.
“Mexoryl should have been available in our country long before it was,” Hale says. Why the delay? As over-the-counter products, sunscreens are regulated by the government. To get approval for a new ingredient, manufacturers have to conduct trials that can cost hundreds of millions of dollars. Mexoryl is the only sunscreen filter to be approved by the FDA in 25 years.
Unlike most chemical sunscreens, Mexoryl is photo-stable, meaning it doesn’t break down when exposed to UV rays. In other words, Mexoryl continues to work even after exposure to UV light; most other sunscreens break down.
Cosmetics giant L’Oreal holds the patent for Mexoryl; it is found in the line’s Ombrelle sunscreen.
Neutrogena has also developed a new complex that protects against UVB and UVA rays. Called Helioplex, the compound contains both avobenzone and oxybenzone.
Protective Clothing
Throwing a white T-shirt over your swimsuit at the beach is a good start, but it’s not nearly enough. According the American Academy of Dermatology (AAD.org), a white tee offers a dismal SPF 3. “Fifty percent of UV rays go right through,” Spencer says. If the shirt gets wet, the SPF decreases even more.
To provide adequate UV protection, the fabric of your clothing should be dark and tightly woven.
But let’s face it, wearing a black track suit on a hot day by the pool isn’t fun. Instead, try washing your summer clothes with a UV-protective product like Rit Sun Guard, a colorless dye you add to your laundry at the beginning of the wash cycle. It can raise the UPF of your clothing up to 30. (UPF is a measurement of how many UV rays pass through clothing and is similar to SPF.) The UV protection lasts for 20 washings and works even if the clothing gets wet.
You can also buy clothing with UPF already built right in. Solumbra clothing, manufactured by Sun Precautions (SunPrecautions.com), is made with a patented fabric equivalent to SPF 30. Styles include chic jackets, feminine tops and beach cover-ups in pretty colors.
Coolibar clothing (Coolibar.com) has a UPF of 50 and offers a variety of loungewear, such as linen blouses, loose-fitting pants and polo tees. Both lines offer children’s clothing as well. |
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