Summer is here, and the beaches are starting to fill. Along the first layers of clothes that were shed, doctors started reminding people not to forget to use sunscreen when they exit their house. The various brands of sunscreens on the market make it difficult for people to choose between brands, SPF degree, and other such features. However, the question remains, what is SPF and how should we choose a sunscreen?

What is SPF?

SPF is the abbreviation for “Sun Protection Factor.” In order to better understand what the acronym stands for it is important to know the scientific process that determines the various SPF degrees of a cream.

When a sunscreen is developed, researchers put some of the lotion on a skin sample and then expose it to ultraviolet radiation (UV). The amount of UV needed to burn the treated skin as opposed to that needed to burn a blank piece of tissue determines the SPF factor.

In other words, if your skin usually reddens after spending roughly 15 minutes in the sun, then a sun lotion with 15 SPF will help you resist the UVs for fifteen times more time. Mathematically, an SPF 15 lotion can protect you for five hours. However, sweating, swimming, and the ever increasing amount of dangerous ultra-violets makes it compulsory to re-apply the cream after two hours.

What is the difference between SPF 15, 30, 50, and 70?

The numbers show not only the amount of time you can safely spend in the sun but also the degree of protection against the entire UV spectrum.

SPF 15 is the most basic cream. It protects the users from approximately 93 percent of ultraviolet rays. SPF 30 can be used to block 97 percent of all rays, SPF 50 is useful against 98 percent of UV rays, and SPF 70 is effective for more than 99 percent of harmful UV rays.

How Should We Choose a Sunscreen?

When selecting a sunscreen, you must bear in mind the type of skin you and your family have. For children, doctors recommend a sun lotion with an SPF factor of 50 and higher.

However, the best way to approach this dilemma is by consulting with a dermatologist. A doctor is the most qualified person to recommend such a product for a safe use.

In conclusion, what is SPF? The number after the acronym designates both the amount of time you can spend in the sun after applying the lotion and the amount of protection against UV rays that the sunscreen offers.

Image source: Wikipedia