Sunscreen is an over-the-counter drug designed to protect your skin from ultraviolet radiation (UV). UV rays can cause wrinkles, age spots, and premature aging. There are three types of UV rays- UVA, UVB, and UVC. They have different wavelength and differs in their biological activity and the depth to which they penetrate into the skin.
UVA is long wavelength (320-400 mm) UV. UVA radiation can penetrate glass and clouds and can be 30 to 50 times more prevalent than UVB rays. UVA rays can penetrate into the deep layers of the skin and cause skin aging, wrinkles, and skin cancers.
UVB is middle-range (290-320 mm) UV. UVB rays do not penetrate glass. Although UVB is less penetrative than UVA, UVB is more intense. UVB causes burning, tanning, acceleration of skin aging and the development of skin cancer.
UVC is the shortest (less than 290 mm) UV. It is filtered by the ozone so it does not reach the earth’s surface. UVC does not contribute to skin damage.
Benefits of Sunscreen
– Minimize the effects of UVA and UVB.
– Shield important proteins such as collagen, elastin, and keratin.
– Protect skin from developing too high concentration of melanin which causes age spots and freckles.
– Help prevent skin from developing skin cancers.
What is SPF?
SPF or Sun Protection Factor indicates relative protection from UVB. The higher the SPF, the more protection a sunscreen offers against UVB.
The SPF number represents the length of time you can stay out in the sun without burning. So, for example, a person who would normally start to burn in 10 minutes, could theoretically have 150 minutes of sun protection with a sunscreen that has an SPF of 15.
What is PA?
PA refers to the amount of protection the sunscreen offers from the UVA rays. PA rankings are listed as PA+, PA++ or PA+++. + indicates the ability of sunscreen to protect the skin from UVA. The more +, the more protection a sunscreen offers against UVA.
What is in Sunscreen?
The active ingredients of sunscreen fall into two broad categories: organic and inorganic. Organic sunscreen absorbs UV rays before they penetrate the skin while inorganic sunscreen reflects UV rays away from the skin. Today, many sunscreens contain a mixture of organic and inorganic ingredients.
How to Choose Sunscreen?
– Select a sunscreen that provides multispectrum protection, broad-spectrum protection or UVA/UVB protection – not just a sunscreen with a high SPF (UVB) rating.
– Choose sunscreen with SPF 15 and above.
-Look for sunscreen with zinc oxide and/or titanium dioxide. These ingredients are insoluble particles which absorb and reflect UV away from the skin.
How to Apply Sunscreen?
Sunscreen should be the last step of skin care regimen so that it can shield your skin and block UV rays. Apply sunscreen after applying moisturize.