Sunscreens – All That You Need To Know

By Marilynn Syrett Published 09/24/2009 | Beauty
Sunscreens are an indispensable part of the skin care regimen. They are characterized by their SPF contents and protect the skin against the harmful radiations emitted by the sun. Here are some things about sunscreens that you need to know...

UV Rays of the Sun

The sun emits three types of ultraviolet rays – UVA, UVB and UVC rays.

The UVC rays are the most dangerous of all. But fortunately, they get absorbed by the atmosphere and do not reach the earth's surface.

The UVB rays, often called the 'burning rays' have a shorter wavelength and are responsible for sun burns caused by exposure to sunlight.

The UVA rays are called the 'aging rays' and are responsible for premature aging of the skin and even skin cancer in extreme cases.

Most sunscreens only protect the skin against UVB rays and not against the UVA rays. Therefore, even though there may not be any visible damage like sun burns, the UVA rays would be penetrating your skin surface and causing damage to the skin cells. Therefore, always use a sunscreen that guarantees “broad spectrum” protection against the sun's rays that shields against both the UVB as well as the UVA rays. Some of the ingredients you should look out for is Avobenzone, Titanium Dioxide, Zinc Oxide and Oxybenzone.

Sun Protection Factor (SPF)

The sun protection factor of a sunscreen is the number that informs about how well the sunscreen protects against the ultraviolet radiations of the sun. It represents the amount of time one can stay out in the sun without getting burnt. According to the SPF of the sunscreen, you can stay out in the sun longer than what you otherwise can without getting burnt.

SPF 15 - 93.3% protection
SPF 30 - 97% protection
SPF 50 - 98% protection

Note: A very high SPF doesn't really guarantee better protection. In fact, anything higher than SPF 50 provides just as much protection as itself. The higher SPF is just because of the increased concentration of chemicals in the product.

Ingredients of Sunscreen

There are basically two types of sunscreens – Physical sunscreens and Chemical Sunscreens.

Chemical sunscreens absorb the UV rays of the sun. This lowers the energy level of UV rays and releases the energy as heat. Common ingredients in chemical sunscreens are avobenzene, oxybenzene, homosalate, octinoxate, and octisalate.

Physical sunscreens scatter and reflect the sun’s UV rays and thus protect the skin. Physical sunscreens are ideal for people who are prone to acne breakouts and skin irritation.Zinc Oxide and Titanium Dioxide are popular ingredients found in physical sunscreens.

Important Facts about Sunscreens

Apply about one shot glass amount of sunscreen. Unless you slather on a thick layer of sunscreen, it would not protect against the UV rays. Applying less than the recommended doses actually causes the SPF to decrease.

Always reapply the sunscreen after every two to four hours in order to get continued protection from the sun's rays. In fact, if you are swimming, exercising or generally sweating a lot, it becomes all the more important to reapply the sunscreen.

Water-resistant or waterproof sunscreens don't guarantee continued protection. It only restrains against water till about 80 minutes. You would still need to reapply it.

Dr. Marilynn Syrett is a graduate from Western University of Health Sciences, College of Osteopathic Medicine Of The Pacific. She has authored several articles about skin care products like Anti-aging Skin Care Products, Sun Tanning & Sunscreens and so on.