What is Sunscreen?
Sunscreen, also commonly known as sun cream, is a lotion, spray, gel or other topical product that absorbs or reflects some of the sun’s ultraviolet (UV) radiation on the skin exposed to sunlight and thus helps protect against sunburn. Skin lightening products have sunscreen to protect lightened skin because light skin is more susceptible to sun damage than darker skin. The sun rays consist of two types of harmful rays:
UVB rays are referred to as “burning” rays. They are the rays that cause us to get sunburns…their effects can be immediate and harmful.
UVA rays are thought of as “aging” rays. These rays are responsible for most skin cancer, as well as signs of premature aging (like wrinkles and sun spots)! The scary fact about UVA rays is that they don’t necessarily produce any visible redness on the skin, so we don’t get any sign when they are bombarding us
Sun Protection Factor (SPF)
The SPF of a sunscreen is a laboratory measure of the effectiveness of sunscreen — the higher the SPF, the more protection a sunscreen offers against UV-B (the ultraviolet radiation that causes sunburn).
Does SPF30 give me Double the Protection as SPF15?
No. Sun Protection Factor (SPF) is a measure of a sunscreen ability to protect against the UVB rays, the rays that cause sunburn. The SPF is the amount of UV radiation required to cause sunburn on skin with the sunscreen on, relative to the amount required without the sunscreen. So, wearing a sunscreen with SPF 15, your skin will not burn until it has been exposed to 15 times the amount of solar energy that would normally cause it to burn. That means that it has cut down the radiation to 1/15 of the original or blocked 14/15 or 93% of UVB rays. Using the same logic SPF 30 stops (1 – 1/30) or 97 percent of UVB rays. If you go as high as SPF 50 it stops 98 percent of UVB rays. But no matter how high the SPF, it is only a protection against UVB, and NOT the UVA. Many sunscreens do not block UVA radiation, which does not cause sunburn but can increase the rate of melanoma, another kind of skin cancer, so people using sunscreens may be getting too much UVA without realizing it. UVA rays also cause premature aging, including wrinkles, sagging and discoloration. To protect against UVA look for sunscreens with ‘broad protection’ on it. “Broad spectrum” sunscreens are designed to protect against both UVB and UVA.
How to Apply Sunscreen:
The dose used in FDA sunscreen testing is 2 mg/cm² of exposed skin. Provided one assumes an “average” adult build of height 5 ft 4 in (163 cm) and weight 150 lb (68 kg) with a 32 in (82 cm) waist, that adult wearing a bathing suit covering the groin area should apply 29 g (approximately 1 oz) evenly to the uncovered body area. Considering only the face, this translates to about 1/4 to 1/3 of a teaspoon for the average adult face. Larger individuals should scale these quantities accordingly.
The thumb rule is that use SPF15 for normal everyday brief exposures and SPF 30 if you are going to stay in the sun for a longer period (for example playing outdoor sports). If you have got very fair or sensitive skin or red hair, use SPF50.
Research indicates that sunscreen needs to be reapplied within 2 hours in order to remain effective. Not reapplying could even cause more cell damage than not using sunscreen at all, due to the release of extra free radicals from those sunscreen chemicals which were absorbed into the skin.
Myth 1: I don’t need to wear sunscreens in winter or on cloudy days: Not true. Although the sun seems less severe in winters or in the rainy seasons you need as much protection from the UV rays in these seasons as in summers.
Myth 2: I don’t need to wear sunscreens if I am wearing long sleeves: UV rays may not be as good as the X-rays but they can penetrate through your clothing. So wear your sunscreen under your long sleeves.
Myth 3: I do not need a sunscreen if I need a tan: There are many other things beside a tanned look that UV rays of the sun cause- cancer, premature aging, including wrinkles, sagging and discoloration. So do yourself a favour and use that SPF tube.