Many types of radiations are emitted by sun. As soon as UVR reach the skin, it is easily absorbed by the skin molecules that mix very strongly with a certain wavelength. This can lead to harming the skin proteins, lipids and cellular DNA, and ultimately causing skin cancer. Ultraviolet radiation is divided into 3 types:
UV-A: It is longest wavelength that crosses the ozone layer and ultimately enters the deeper layers of skin.
UV-B: It is partly blocked by the ozone layer and is responsible for sunburns.
UV-C: It is completely absorbed by the atmosphere, and the only places you get it are artificial radiation sources.
Sunscreens can absorb or redirect these dangerous rays prior to their interaction with the skin. A sunscreen usually contains a mixture of chemical and moisturizing constituents. Some ingredients can effectively block UVB while others block UVA. Chemical sunscreen constituents are: PABA esters, cinnamates, para-aminobenzoic acid (PABA), benzophenes, salicylates, octocrylene and dibenzoyl-methane. Titanium dioxide and zinc oxide are physical blockers and board spectrum and can protect against both UVB and UVA.
What does SPF mean
SPF means Sun Protection Factor. The number is decided and set by the amount of light that causes redness in skins, protected by sunscreen and separated by the amount of light that causes redness in unprotected skins is called as SPF. It is a measure of protection against UVB and lies between 1-45+. A sunscreen product with SPF of 15 will block 92% of the UVB. Alternatively, a sunscreen product with SPF 15 will delay the start of sunburn in a person who would normally burn within 10 minutes to burn in 150 minutes. The SPF 15 sunscreen lets a person stay out in the sun 15 times longer.
Sunscreen Applications and Selection
1) Always read the label before purchasing a sunscreen product. Ensure it can block and absorb both UVA and UVB.
2) Find out level of protection offered by the product. Choose it depending on how long you plan to remain in the sun.
3) Cheaper brands are equally effective as the costlier brands.
4) Find out the expiry date. An expired product will not be effective and so will not yield results. This can cause severe sun burn.
5) Buy a product, labeled board spectrum, for total skin protection against UVB, UVA and UVC.
6) As lighter skin tends to burn faster than darker skin, always go for higher SPF if you have light skin.
7) Ensure product complies and adheres to the standard AS/NZS2604 to bolster their claims and declaration of SPF, water resistance and board spectrum. It should be mentioned on their label.
8) Read the products formulation. It must be hypoallergenic, making it safer to apply on sensitive skin and face. It should be nonacnegenic to prevent the clogging of the pores.
9) Go for a PABA-free product, as it is free from irritating chemicals and can be safely applied on the face.
10) Always go for waterproof sunscreen.
11) Read the label to check that besides sun protection, it also has necessary skin moisturizers to nurture your skin.
12) Clean and dry your skin prior to applying a sunscreen to help in its proper absorption.
13) Apply sunscreen generously all over the body and be more careful to the face, nose, ears, cheeks, and scalp since these areas are more likely to suffer from sun burn.
14) Keep on reapplying if sweating profusely or swimming. It is recommended to apply it 15 minutes before venturing out in the sun.
16) Don’t forget to apply sunscreen even on cloudy days.
17) Stay out of the sun during the hottest hours of the day even though you have applied sunscreen. This period is normally between 10-4.
18) Reflectors like zinc cream fend UV rays off the skin, and should be applied on small parts of the skin because they are likely to reduce sweating.