If you need to test the convincing ability of commercials, then simply watch sunscreen lotion advertisements on your TV. Watching all those pretty women on the beach, scantily dressed, playing volleyball, basking in the sun, and remaining fair-skinned, has thousands of women and even men running to the nearest store just to buy that magical X sunscreen. Well, sunscreen lotions are available in a wide variety of sunscreen ratings (SPF ratings) which makes choosing the ideal sunscreen lotion a real headache for many people. But what is SPF, and how does it determine the type of sunscreen that you are supposed to choose? Well, read on!
What is Sunscreen SPF?
First and foremost, for those who are not knowledgeable about the purpose or necessity of sunscreens, SPF in full form is 'Sun Protection Factor'. Prolonged exposure of the skin to the sun always lead to sunburns (skin reddening). Applying sunscreen lotion to the exposed areas of the skin protects it from the harmful UV rays from the sun, and also minimizes the risk of skin problems, such as skin cancer. Now that you understand the use of sunscreen, let us tackle the different types of SPF sun protection ratings. When a certain sunscreen lotion is advertised to be SPF 30, what does this mean?
Different Types of SPF Ratings
In simple words, the SPF rating of a sunblock lotion indicates how long the sunscreen will remain effective and not how strong it is. Here is an example.
Let’s assume you have two sunscreen lotions, with one having SPF 30 and the other having SPF 15. There is a misconception that the actual SPF numbers themselves show how much time the sunscreen will remain effective. However, the SPF numbers are multiplied by what is known as a constant in mathematical terms. This constant is simply how much time your skin takes to show signs of sunburn or reddening, when left exposed to the hot sun.
That means, if your skin takes 20 minutes to redden when left exposed to the sun, then 20 is your constant. Now, you can calculate how much time the sunscreen will remain effective by simply multiplying your individual constant with the SPF rating of the lotion. So, if your sunscreen lotion has SPF 15 and your constant is 20, then you get 15 x 20 = 300 minutes. This is the time for which the sunblock lotion will remain effective once you have applied it.
The constant will definitely vary from one individual to another. For you, it can be 20 minutes while for someone else, 10 minutes of exposure to direct sunlight could be what it takes for the skin to redden. This implies that the safe duration with regards to direct exposure to sunlight does not remain constant for every individual, even if they apply the same sunscreen lotion. For example, consider a case where you and your spouse go for sunbathing at the beach for 3 hours and you both use an SPF 15 sunblock lotion. If you have a constant of 20 while your partner has 10, this implies that the SPF 15 lotion will protect your skin for 300 minutes, while it would protect your spouse for only 150 minutes! Therefore, your partner will have to reapply the lotion after about two hours, or go for a higher SPF sunscreen, like SPF 30 sunscreen.
Generally, sunscreen lotions with 30 and 50 SPF ratings are ideal for outdoor activities such as sunbathing, swimming, sea bathing etc. Water and sweat often make the sunscreen lotion to wear off the body, so it is important to reapply it regularly in such cases. It advisable look for sunscreen lotions containing titanium dioxide and zinc oxide as they offer excellent protection.
Now that you understand the meaning and importance of SPF sunscreen ratings, the next step is to buy the best lotion for your skin. The key to buying the best sunscreen lotions in the market is to shop around. Besides SPF, there are other factors you need to consider when buying a sunscreen lotion such as how it feels on your skin, easy application on the skin, the part of the body to be protected and the activities you are participating in. Remember, in addition to using a sunscreen, it is also important to wear sun protective clothing to ensure proper protection of the skin from sunlight.